From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f69.google.com (mail-oa1-f69.google.com [209.85.160.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 70BA223E334 for ; Sun, 11 Oct 2026 16:23:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791735833; cv=none; b=rxRv8A1/88Iwz5Yl24I6i1HvkwLH57l633OPEOlFkZ0zqTD/gtRWlTYPObFTasEJEs/HuDLnMOSY+kqjcV4+jPzRk/YWgQIgiQRWrlsM3lqGuChqjVAK8Hlmpl1jpneXAcdLS7MyMqg4CYcWnRxGEEknhQdYhEKcY/or//ddJp8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791735833; c=relaxed/simple; bh=JUwjomTlAKVJV5nYwGFv2nU/PWDojowyesQQwPj5t2Q=; h=MIME-Version:Date:Message-ID:Subject:From:To:Cc:Content-Type; b=A/958G4/C/U1VqnulweujbKv4S1MP0GPNfRiTWze1jXr5p+tIhQnRkObuHrp2tPtzDPn5kRBUVwH3EV8uyXp3d8gBaStjlr9/4UwX0jZKdIamso6Fhzgm5VEkMJY+xbYYSbxbgnqx1S4wLRdO2cqBa91skQr/rv0fzsYAuflFX4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.160.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oa1-f69.google.com with SMTP id 586e51a60fabf-45e6091d8a1so1156687fac.1 for ; Sun, 11 Oct 2026 09:23:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791735824; x=1792340624; h=content-type:cc:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=3YrgsTRGa2qmLgFiS7PKDXFLCFAqgOsjj7OVvrJxYfk=; b=b7ctJDw8gFb9AWSnfR/gnPO5rSEn9XleUkefZ1Ns+9BSgCJLRlfskaIQsRjJJsEXkj I9DRJdSt99aRrEfnM2vsOGQEc5h66nvTPcrLFp5CNRqpQURCx4exTMIdG+gYrYHrm08n 6rGDpjI4/f0SeW01CW7KAkgxn69dyF0a41/IbPTo4a66GAB7TSMnEZegorUf7BbUjEyy 4IuT0PMN2w3Mv3pURUT9dQ9OaGutlDB5pU/qIiG9EaHkxgbGSfE5IkeOGKf1RxOsgnxB l153wy7CZowKLGrtQL49Yu8pn2bu17h35ZryBhlEDbdwJDXEEdVHG4Any4dOucawExkK LbPQ== X-Gm-Message-State: AFq9FYKVWjIhtM26/DjszCMEjNjH7Go6VVh+d2AdpGXyCBCGcuyE0nHn Tabw+lmK2wp3/5zpQ23EXuVaWJmJfN6vFN/4ZOAalgfkNsYlLRrecIQx+ZpA4FhHcYMj3kfeA0A sl6vRw0F/XA6o+s1FQIM7P1CZ1UNEFgM6DZQon1pSjqLsK92XReAJY+ktQmU= Precedence: bulk X-Mailing-List: syzbot@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:191e:b0:4f9:6348:cd3b with SMTP id 5614622812f47-50c55b860a9mr7820798b6e.41.1791735824196; Sun, 11 Oct 2026 09:23:44 -0700 (PDT) Date: Sun, 11 Oct 2026 09:23:44 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6acbb810.bbc4c7f9.15faa7.0086.GAE@google.com> Subject: [moderation/CI] Re: loop: Detect write requests that failed to wait for completion. From: syzbot ci To: syzkaller-upstream-moderation@googlegroups.com Cc: syzbot@lists.linux.dev Content-Type: text/plain; charset="UTF-8" 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