All of lore.kernel.org
 help / color / mirror / Atom feed
* [moderation/CI] Re: loop: Detect write requests that failed to wait for completion.
@ 2026-10-11 15:15 syzbot ci
  0 siblings, 0 replies; 4+ messages in thread
From: syzbot ci @ 2026-10-11 15:15 UTC (permalink / raw)
  To: syzkaller-upstream-moderation; +Cc: syzbot

syzbot ci has tested the following series

[v1] loop: Detect write requests that failed to wait for completion.
https://lore.kernel.org/all/380f04ef-902d-4664-9ae3-228692d2efb9@I-love.SAKURA.ne.jp
* [PATCH] loop: Detect write requests that failed to wait for completion.

and found the following issues:
* BUG: syz.NUM.NUM/NUM is doing I/O request on loop1 in Lo_rundown state.
* BUG: syz.NUM.NUM/NUM is doing I/O request on loop4 in Lo_rundown state.

Full report is available here:
https://ci.syzbot.org/series/1d6e1ed8-5255-4499-b944-1491f0fc2111

***

BUG: syz.NUM.NUM/NUM is doing I/O request on loop1 in Lo_rundown state.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/9ff9d467-08f4-48f3-814f-1605ea27467a/config
syz repro: https://ci.syzbot.org/findings/2daf7154-e0e1-4e75-863e-48d5787f46d1/syz_repro

BUG: syz.1.1804/9447 is doing I/O request on loop1 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0 drivers/block/loop.c:1902
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.1.1804/9447 is doing I/O request on loop1 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0 drivers/block/loop.c:1902
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.1.1804/9447 is doing I/O request on loop1 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0 drivers/block/loop.c:1902
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.1.1804/9447 is doing I/O request on loop1 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0 drivers/block/loop.c:1902
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.1.1804/9447 is doing I/O request on loop1 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0 drivers/block/loop.c:1902
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state


***

BUG: syz.NUM.NUM/NUM is doing I/O request on loop4 in Lo_rundown state.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/9ff9d467-08f4-48f3-814f-1605ea27467a/config
AI triage: https://ci.syzbot.org/findings/99783fd2-a03a-4f81-a151-fc2aaea45886/triage_trajectory

BUG: syz.4.84/6446 is doing I/O request on loop4 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.4.84/6446 is doing I/O request on loop4 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.4.84/6446 is doing I/O request on loop4 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.4.84/6446 is doing I/O request on loop4 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.4.84/6446 is doing I/O request on loop4 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.4.84/6446 is doing I/O request on loop4 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.4.84/6446 is doing I/O request on loop4 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: syz.4.84/6446 is doing I/O request on loop4 in Lo_rundown state.
Call Trace:
     loop_queue_rq+0x8b/0xed0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.

Notes:
- The patch will be applied on top of the tested series (as an
  incremental fix).
- To test a new version of the whole series, please send it directly
  to syzbot@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.

The email will later be sent to:
[axboe@kernel.dk bvanassche@acm.org eadavis@qq.com hch@lst.de jfs-discussion@lists.sourceforge.net linux-block@vger.kernel.org nilay@linux.ibm.com penguin-kernel@i-love.sakura.ne.jp shaggy@kernel.org]

If the report looks fine to you, reply with:
#syz upstream

If the report is a false positive, reply with
#syz invalid


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [moderation/CI] Re: loop: Detect write requests that failed to wait for completion.
@ 2026-10-11 16:23 syzbot ci
  0 siblings, 0 replies; 4+ messages in thread
From: syzbot ci @ 2026-10-11 16:23 UTC (permalink / raw)
  To: syzkaller-upstream-moderation; +Cc: syzbot

syzbot ci has tested the following series

[v2] loop: Detect write requests that failed to wait for completion.
https://lore.kernel.org/all/696e5e7c-e3f1-4181-be2a-8915fd1753cf@I-love.SAKURA.ne.jp
* [PATCH v2] loop: Detect write requests that failed to wait for completion.

and found the following issues:
* BUG: loop0 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.
* BUG: loop1 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.
* BUG: loop2 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.
* BUG: loop3 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.
* BUG: loop4 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.

Full report is available here:
https://ci.syzbot.org/series/76836433-2e8b-4ec6-910a-ff3ed4a39a9d

***

BUG: loop0 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/a9ce0306-33bb-438b-b7e8-a71d334ea05a/config
syz repro: https://ci.syzbot.org/findings/697b1531-4355-43f2-abf4-67f34fb95053/syz_repro

BUG: loop0 has no users, but backend found I/O issued by syz.0.19/5781.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.19/5781.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.19/5781.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.47/5809.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f


***

BUG: loop1 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/a9ce0306-33bb-438b-b7e8-a71d334ea05a/config
syz repro: https://ci.syzbot.org/findings/b07804ae-02b6-47e8-8a4b-462c9ca5d6e3/syz_repro

BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.25/5812.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.27/5816.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.65/5953.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.98/6019.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.98/6019.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.98/6019.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.98/6019.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.98/6019.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop0 has no users, but backend found I/O issued by syz.0.98/6019.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop1 has no users, but backend found I/O issued by syz.1.124/6071.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f


***

BUG: loop2 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/a9ce0306-33bb-438b-b7e8-a71d334ea05a/config
syz repro: https://ci.syzbot.org/findings/e242f078-0279-4480-a331-d902d1ccb008/syz_repro

BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop2 has no users, but backend found I/O issued by syz.2.35/5886.
Call Trace:
     loop_queue_rq+0x82/0xcb0 drivers/block/loop.c:1890
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f


***

BUG: loop3 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/a9ce0306-33bb-438b-b7e8-a71d334ea05a/config
AI triage: https://ci.syzbot.org/findings/abd85940-485e-443b-acb7-5a684fdd8cb9/triage_trajectory

BUG: loop3 has no users, but backend found I/O issued by syz.3.573/12573.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     ocfs2_read_blocks+0x85e/0x14d0
     ocfs2_read_virt_blocks+0x3e5/0x9c0
     ocfs2_find_entry+0x3c3/0x2050
     ocfs2_find_files_on_disk+0xe0/0x340
     ocfs2_lookup_ino_from_name+0x52/0x100
     ocfs2_get_system_file_inode+0x32f/0x810
     ocfs2_init_global_system_inodes+0x318/0x6e0
     ocfs2_fill_super+0x456e/0x6840
     get_tree_bdev_flags+0x430/0x4f0
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop3 has no users, but backend found I/O issued by syz.3.573/12573.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     ocfs2_read_blocks+0x85e/0x14d0
     ocfs2_read_virt_blocks+0x3e5/0x9c0
     ocfs2_find_entry+0x3c3/0x2050
     ocfs2_find_files_on_disk+0xe0/0x340
     ocfs2_lookup_ino_from_name+0x52/0x100
     ocfs2_get_system_file_inode+0x32f/0x810
     ocfs2_init_global_system_inodes+0x318/0x6e0
     ocfs2_fill_super+0x456e/0x6840
     get_tree_bdev_flags+0x430/0x4f0
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop3 has no users, but backend found I/O issued by syz.3.573/12573.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     ocfs2_read_blocks+0x85e/0x14d0
     ocfs2_read_virt_blocks+0x3e5/0x9c0
     ocfs2_find_entry+0x3c3/0x2050
     ocfs2_find_files_on_disk+0xe0/0x340
     ocfs2_lookup_ino_from_name+0x52/0x100
     ocfs2_get_system_file_inode+0x32f/0x810
     ocfs2_init_global_system_inodes+0x318/0x6e0
     ocfs2_fill_super+0x456e/0x6840
     get_tree_bdev_flags+0x430/0x4f0
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop3 has no users, but backend found I/O issued by syz.3.573/12573.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     ocfs2_read_blocks+0x85e/0x14d0
     ocfs2_read_virt_blocks+0x3e5/0x9c0
     ocfs2_find_entry+0x3c3/0x2050
     ocfs2_find_files_on_disk+0xe0/0x340
     ocfs2_lookup_ino_from_name+0x52/0x100
     ocfs2_get_system_file_inode+0x32f/0x810
     ocfs2_init_global_system_inodes+0x318/0x6e0
     ocfs2_fill_super+0x456e/0x6840
     get_tree_bdev_flags+0x430/0x4f0
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop3 has no users, but backend found I/O issued by syz.3.573/12573.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     ocfs2_read_blocks+0x85e/0x14d0
     ocfs2_read_virt_blocks+0x3e5/0x9c0
     ocfs2_find_entry+0x3c3/0x2050
     ocfs2_find_files_on_disk+0xe0/0x340
     ocfs2_lookup_ino_from_name+0x52/0x100
     ocfs2_get_system_file_inode+0x32f/0x810
     ocfs2_init_global_system_inodes+0x318/0x6e0
     ocfs2_fill_super+0x456e/0x6840
     get_tree_bdev_flags+0x430/0x4f0
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop3 has no users, but backend found I/O issued by syz.3.573/12573.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     ocfs2_read_blocks+0x85e/0x14d0
     ocfs2_read_virt_blocks+0x3e5/0x9c0
     ocfs2_find_entry+0x3c3/0x2050
     ocfs2_find_files_on_disk+0xe0/0x340
     ocfs2_lookup_ino_from_name+0x52/0x100
     ocfs2_get_system_file_inode+0x32f/0x810
     ocfs2_init_global_system_inodes+0x318/0x6e0
     ocfs2_fill_super+0x456e/0x6840
     get_tree_bdev_flags+0x430/0x4f0
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop3 has no users, but backend found I/O issued by syz.3.573/12573.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     ocfs2_read_blocks+0x85e/0x14d0
     ocfs2_read_virt_blocks+0x3e5/0x9c0
     ocfs2_find_entry+0x3c3/0x2050
     ocfs2_find_files_on_disk+0xe0/0x340
     ocfs2_lookup_ino_from_name+0x52/0x100
     ocfs2_get_system_file_inode+0x32f/0x810
     ocfs2_init_global_system_inodes+0x318/0x6e0
     ocfs2_fill_super+0x456e/0x6840
     get_tree_bdev_flags+0x430/0x4f0
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
ntfs3(loop9): ino=5, mi_enum_attr
ntfs3(loop9): ino=5, mi_enum_attr


***

BUG: loop4 has no users, but backend found I/O issued by syz.NUM.NUM/NUM.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/a9ce0306-33bb-438b-b7e8-a71d334ea05a/config
AI triage: https://ci.syzbot.org/findings/4b53dd56-32be-4fad-98f2-7631c2f9c672/triage_trajectory

BUG: loop4 has no users, but backend found I/O issued by syz.4.3047/1758.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop4 has no users, but backend found I/O issued by syz.4.3047/1758.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop4 has no users, but backend found I/O issued by syz.4.3047/1758.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop4 has no users, but backend found I/O issued by syz.4.3047/1758.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop4 has no users, but backend found I/O issued by syz.4.3047/1758.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: loop4 has no users, but backend found I/O issued by syz.4.3047/1758.
Call Trace:
     loop_queue_rq+0x82/0xcb0
     blk_mq_try_issue_directly+0x3f4/0x880
     blk_mq_submit_bio+0x21de/0x2bb0
     submit_bio_noacct_nocheck+0x2f4/0xa40
     __breadahead+0x15c/0x1f0
     nilfs_search_super_root+0x2be/0x1530
     load_nilfs+0x363/0xfb0
     nilfs_fill_super+0x1a0/0x4e0
     nilfs_get_tree+0x491/0x850
     vfs_get_tree+0x92/0x2a0
     do_new_mount+0x319/0xdc0
     __se_sys_mount+0x31d/0x420
     do_syscall_64+0x166/0x520
     entry_SYSCALL_64_after_hwframe+0x77/0x7f


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.

Notes:
- The patch will be applied on top of the tested series (as an
  incremental fix).
- To test a new version of the whole series, please send it directly
  to syzbot@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.

The email will later be sent to:
[axboe@kernel.dk bvanassche@acm.org eadavis@qq.com hch@lst.de jfs-discussion@lists.sourceforge.net linux-block@vger.kernel.org nilay@linux.ibm.com penguin-kernel@i-love.sakura.ne.jp shaggy@kernel.org]

If the report looks fine to you, reply with:
#syz upstream

If the report is a false positive, reply with
#syz invalid


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [moderation/CI] Re: loop: Detect write requests that failed to wait for completion.
@ 2026-10-11 17:38 syzbot ci
  2026-10-11 19:21 ` Aleksandr Nogikh
  0 siblings, 1 reply; 4+ messages in thread
From: syzbot ci @ 2026-10-11 17:38 UTC (permalink / raw)
  To: syzkaller-upstream-moderation; +Cc: syzbot

syzbot ci has tested the following series

[v3] loop: Detect write requests that failed to wait for completion.
https://lore.kernel.org/all/cc2910d3-3113-44d4-94ef-0c8d365fac9c@I-love.SAKURA.ne.jp
* [PATCH v3] loop: Detect write requests that failed to wait for completion.

and found the following issues:
* BUG: found I/O issued by syz.NUM.NUM/NUM but loop0 is no longer bound.
* BUG: found I/O issued by syz.NUM.NUM/NUM but loop2 is no longer bound.

Full report is available here:
https://ci.syzbot.org/series/d3a0b036-fd1e-44c6-8869-386ea1642385

***

BUG: found I/O issued by syz.NUM.NUM/NUM but loop0 is no longer bound.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/a23afb97-88bb-4fba-8885-d3062b5890e2/config
syz repro: https://ci.syzbot.org/findings/c9ad5ff9-784f-4528-805f-7971e0359600/syz_repro

BUG: found I/O issued by syz.0.760/7647 but loop0 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.0.760/7647 but loop0 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f


***

BUG: found I/O issued by syz.NUM.NUM/NUM but loop2 is no longer bound.

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/a23afb97-88bb-4fba-8885-d3062b5890e2/config
syz repro: https://ci.syzbot.org/findings/bad9ae98-7887-4209-8226-7e84bb070faa/syz_repro

BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
Call Trace:
     loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
     __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
     blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
     blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
     __submit_bio_noacct_mq block/blk-core.c:756 [inline]
     submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
     bh_submit fs/buffer.c:1146 [inline]
     __bh_read fs/buffer.c:2943 [inline]
     bh_readahead include/linux/buffer_head.h:437 [inline]
     __breadahead+0x15c/0x1f0 fs/buffer.c:1359
     nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
     load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
     nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
     nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
     vfs_get_tree+0x92/0x2a0 fs/super.c:1932
     fc_mount fs/namespace.c:1198 [inline]
     do_new_mount_fc fs/namespace.c:3772 [inline]
     do_new_mount+0x319/0xdc0 fs/namespace.c:3848
     do_mount fs/namespace.c:4181 [inline]
     __do_sys_mount fs/namespace.c:4397 [inline]
     __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
     do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
     do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
     entry_SYSCALL_64_after_hwframe+0x77/0x7f


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.

Notes:
- The patch will be applied on top of the tested series (as an
  incremental fix).
- To test a new version of the whole series, please send it directly
  to syzbot@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.

The email will later be sent to:
[axboe@kernel.dk bvanassche@acm.org eadavis@qq.com hch@lst.de jfs-discussion@lists.sourceforge.net linux-block@vger.kernel.org nilay@linux.ibm.com penguin-kernel@i-love.sakura.ne.jp shaggy@kernel.org]

If the report looks fine to you, reply with:
#syz upstream

If the report is a false positive, reply with
#syz invalid


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [moderation/CI] Re: loop: Detect write requests that failed to wait for completion.
  2026-10-11 17:38 syzbot ci
@ 2026-10-11 19:21 ` Aleksandr Nogikh
  0 siblings, 0 replies; 4+ messages in thread
From: Aleksandr Nogikh @ 2026-10-11 19:21 UTC (permalink / raw)
  To: syzbot ci; +Cc: syzkaller-upstream-moderation, syzbot

#syz upstream

On Sun, Oct 11, 2026 at 7:38 PM syzbot ci
<syzbot+ciebc1a7ad3d6a80ae@syzkaller.appspotmail.com> wrote:
>
> syzbot ci has tested the following series
>
> [v3] loop: Detect write requests that failed to wait for completion.
> https://lore.kernel.org/all/cc2910d3-3113-44d4-94ef-0c8d365fac9c@I-love.SAKURA.ne.jp
> * [PATCH v3] loop: Detect write requests that failed to wait for completion.
>
> and found the following issues:
> * BUG: found I/O issued by syz.NUM.NUM/NUM but loop0 is no longer bound.
> * BUG: found I/O issued by syz.NUM.NUM/NUM but loop2 is no longer bound.
>
> Full report is available here:
> https://ci.syzbot.org/series/d3a0b036-fd1e-44c6-8869-386ea1642385
>
> ***
>
> BUG: found I/O issued by syz.NUM.NUM/NUM but loop0 is no longer bound.
>
> tree:      axboe
> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
> base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
> arch:      amd64
> compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
> config:    https://ci.syzbot.org/builds/a23afb97-88bb-4fba-8885-d3062b5890e2/config
> syz repro: https://ci.syzbot.org/findings/c9ad5ff9-784f-4528-805f-7971e0359600/syz_repro
>
> BUG: found I/O issued by syz.0.760/7647 but loop0 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.0.760/7647 but loop0 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
>
> ***
>
> BUG: found I/O issued by syz.NUM.NUM/NUM but loop2 is no longer bound.
>
> tree:      axboe
> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
> base:      4da93acb4f2ed06640255ad98801d0f0c734ff07
> arch:      amd64
> compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
> config:    https://ci.syzbot.org/builds/a23afb97-88bb-4fba-8885-d3062b5890e2/config
> syz repro: https://ci.syzbot.org/findings/bad9ae98-7887-4209-8226-7e84bb070faa/syz_repro
>
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> BUG: found I/O issued by syz.2.866/7955 but loop2 is no longer bound.
> Call Trace:
>      loop_queue_rq+0x232/0xc90 drivers/block/loop.c:1922
>      __blk_mq_issue_directly block/blk-mq.c:2708 [inline]
>      blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2768
>      blk_mq_submit_bio+0x21de/0x2bb0 block/blk-mq.c:3220
>      __submit_bio_noacct_mq block/blk-core.c:756 [inline]
>      submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
>      bh_submit fs/buffer.c:1146 [inline]
>      __bh_read fs/buffer.c:2943 [inline]
>      bh_readahead include/linux/buffer_head.h:437 [inline]
>      __breadahead+0x15c/0x1f0 fs/buffer.c:1359
>      nilfs_search_super_root+0x2be/0x1530 fs/nilfs2/recovery.c:891
>      load_nilfs+0x363/0xfb0 fs/nilfs2/the_nilfs.c:259
>      nilfs_fill_super+0x1a0/0x4e0 fs/nilfs2/super.c:1073
>      nilfs_get_tree+0x491/0x850 fs/nilfs2/super.c:1226
>      vfs_get_tree+0x92/0x2a0 fs/super.c:1932
>      fc_mount fs/namespace.c:1198 [inline]
>      do_new_mount_fc fs/namespace.c:3772 [inline]
>      do_new_mount+0x319/0xdc0 fs/namespace.c:3848
>      do_mount fs/namespace.c:4181 [inline]
>      __do_sys_mount fs/namespace.c:4397 [inline]
>      __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
>      do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>      do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
>
> ***
>
> If these findings have caused you to resend the series or submit a
> separate fix, please add the following tag to your commit message:
>   Tested-by: syzbot@syzkaller.appspotmail.com
>
> ---
> This report is generated by a bot. It may contain errors.
> syzbot ci engineers can be reached at syzkaller@googlegroups.com.
>
> To test a fix for this bug, please reply with `#syz test`
> (on a separate line) and attach the patch to the email.
>
> Notes:
> - The patch will be applied on top of the tested series (as an
>   incremental fix).
> - To test a new version of the whole series, please send it directly
>   to syzbot@lists.linux.dev.
> - Arguments like custom git repos and branches are not supported.
>
> The email will later be sent to:
> [axboe@kernel.dk bvanassche@acm.org eadavis@qq.com hch@lst.de jfs-discussion@lists.sourceforge.net linux-block@vger.kernel.org nilay@linux.ibm.com penguin-kernel@i-love.sakura.ne.jp shaggy@kernel.org]
>
> If the report looks fine to you, reply with:
> #syz upstream
>
> If the report is a false positive, reply with
> #syz invalid
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-upstream-moderation" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-upstream-moderation+unsubscribe@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-upstream-moderation/6acbc9a8.6d14cce4.2677ed.012d.GAE%40google.com.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2026-10-11 19:21 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-10-11 16:23 [moderation/CI] Re: loop: Detect write requests that failed to wait for completion syzbot ci
  -- strict thread matches above, loose matches on Subject: below --
2026-10-11 17:38 syzbot ci
2026-10-11 19:21 ` Aleksandr Nogikh
2026-10-11 15:15 syzbot ci

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.