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From: syzbot ci <syzbot+ci6aeba55b683f90f0@syzkaller.appspotmail.com>
To: syzkaller-upstream-moderation@googlegroups.com
Cc: syzbot@lists.linux.dev
Subject: [moderation/CI] Re: loop: Detect write requests that failed to wait for completion.
Date: Sun, 11 Oct 2026 09:23:44 -0700	[thread overview]
Message-ID: <6acbb810.bbc4c7f9.15faa7.0086.GAE@google.com> (raw)

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


             reply	other threads:[~2026-10-11 16:23 UTC|newest]

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

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