[bug report] WARNING: block/blk-mq-debugfs.c:620 at debugfs_create_files.isra.0+0x54/0x60, CPU#220: kworker/u1036:7/70421
Shinichiro Kawasaki
shinichiro.kawasaki at wdc.com
Thu Feb 5 23:25:41 PST 2026
On Feb 03, 2026 / 20:28, Yi Zhang wrote:
> Hello
>
> CKI reported the following failure today. Seems it was introduced from
> the recently blk-mq-debugfs update, please help check and let me know
> if you need any testing/info.
>
> Reproducer: blktests nvme/tcp nvme/005
> Commit message: Merge branch 'for-7.0/block' into for-next
>
> dmesg:
> [ 951.319384] run blktests nvme/005 at 2026-02-02 17:59:35
> [ 951.346116] loop0: detected capacity change from 0 to 2097152
> [ 951.356428] nvmet: adding nsid 1 to subsystem blktests-subsystem-1
> [ 951.370823] nvmet_tcp: enabling port 0 (127.0.0.1:4420)
> [ 951.397438] nvmet: Created nvm controller 1 for subsystem
> blktests-subsystem-1 for NQN
> nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.
> [ 951.412081] nvme nvme0: creating 128 I/O queues.
> [ 951.425914] nvme nvme0: mapped 128/0/0 default/read/poll queues.
> [ 951.467027] nvme nvme0: new ctrl: NQN "blktests-subsystem-1", addr
> 127.0.0.1:4420, hostnqn:
> nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349
> [ 951.784608] nvmet: Created nvm controller 2 for subsystem
> blktests-subsystem-1 for NQN
> nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.
> [ 951.798920] nvme nvme0: creating 128 I/O queues.
> [ 951.871600] nvme nvme0: mapped 128/0/0 default/read/poll queues.
> [ 951.880680] ------------[ cut here ]------------
> [ 951.885309] WARNING: block/blk-mq-debugfs.c:620 at
> debugfs_create_files.isra.0+0x54/0x60, CPU#220: kworker/u1036:7/70421
FYI, I also observe this WARN at debugfs_create_files() using the blktests test
case zbd/012. When I repeat zbd/012 several times on the kernel with the tag
next-20260204, the WARN below is reported:
[ 1304.543824] [ T12755] ------------[ cut here ]------------
[ 1304.545792] [ T12755] WARNING: block/blk-mq-debugfs.c:620 at debugfs_create_files+0x247/0x2c0, CPU#2: check/12755
[ 1304.547377] [ T12755] Modules linked in: scsi_debug null_blk nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables qrtr sunrpc 9pnet_virtio 9pnet pcspkr netfs i2c_piix4 i2c_smbus loop fuse dm_multipath nfnetlink vsock_loopback vmw_vsock_virtio_transport_common zram vsock xfs bochs drm_client_lib drm_shmem_helper drm_kms_helper nvme drm nvme_core floppy sym53c8xx nvme_keyring e1000 scsi_transport_spi nvme_auth hkdf serio_raw ata_generic pata_acpi i2c_dev qemu_fw_cfg [last unloaded: scsi_debug]
[ 1304.554851] [ T12755] CPU: 2 UID: 0 PID: 12755 Comm: check Not tainted 6.19.0-rc8-next-20260204 #383 PREEMPT(full)
[ 1304.556421] [ T12755] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014
[ 1304.557886] [ T12755] RIP: 0010:debugfs_create_files+0x247/0x2c0
[ 1304.559074] [ T12755] Code: ff e8 1d b0 83 01 83 f8 01 0f 85 67 fe ff ff 0f 0b e9 60 fe ff ff 0f 0b e9 59 fe ff ff 48 89 ef e8 2e 59 69 ff e9 07 fe ff ff <0f> 0b e9 6e ff ff ff e8 fd 58 69 ff e9 9a fe ff ff 48 89 df e8 30
[ 1304.562112] [ T12755] RSP: 0018:ffff888147b77530 EFLAGS: 00010202
[ 1304.563343] [ T12755] RAX: 0000000000000000 RBX: ffffffffaa567360 RCX: 0000000000000001
[ 1304.564728] [ T12755] RDX: 0000000000000001 RSI: ffffffffaae6910d RDI: ffff888130361a48
[ 1304.566104] [ T12755] RBP: ffffffffabe49734 R08: 0000000000000001 R09: ffffed1022804075
[ 1304.567487] [ T12755] R10: 0000000000000002 R11: ffff88812610c390 R12: ffff8881140202f0
[ 1304.568850] [ T12755] R13: ffff888130361310 R14: ffff888130361310 R15: ffffffffaa567af0
[ 1304.570246] [ T12755] FS: 00007f40d67a1740(0000) GS:ffff8884011ea000(0000) knlGS:0000000000000000
[ 1304.571721] [ T12755] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1304.573019] [ T12755] CR2: 000000001e02a810 CR3: 00000001148f6000 CR4: 00000000000006f0
[ 1304.574409] [ T12755] Call Trace:
[ 1304.575361] [ T12755] <TASK>
[ 1304.576229] [ T12755] blk_mq_sched_reg_debugfs+0x28/0xe0
[ 1304.577287] [ T12755] elevator_change_done+0x2f2/0x610
[ 1304.578342] [ T12755] ? lockdep_hardirqs_on_prepare+0x50/0x1b0
[ 1304.579452] [ T12755] ? __pfx_elevator_change_done+0x10/0x10
[ 1304.580469] [ T12755] ? find_held_lock+0x2b/0x80
[ 1304.581346] [ T12755] ? elevator_change+0x2ed/0x4f0
[ 1304.582246] [ T12755] ? lock_release+0x1a7/0x320
[ 1304.583142] [ T12755] ? __pfx_sysfs_kf_write+0x10/0x10
[ 1304.584087] [ T12755] elevator_change+0x283/0x4f0
[ 1304.584970] [ T12755] ? __pfx_sysfs_kf_write+0x10/0x10
[ 1304.585887] [ T12755] elv_iosched_store+0x31d/0x3a0
[ 1304.586784] [ T12755] ? __pfx_elv_iosched_store+0x10/0x10
[ 1304.587724] [ T12755] ? lock_acquire+0x1b0/0x340
[ 1304.588597] [ T12755] ? kernfs_fop_write_iter+0x257/0x5e0
[ 1304.589523] [ T12755] ? __pfx___might_resched+0x10/0x10
[ 1304.590396] [ T12755] ? __might_fault+0x97/0x140
[ 1304.591265] [ T12755] ? __pfx_sysfs_kf_write+0x10/0x10
[ 1304.592185] [ T12755] queue_attr_store+0x235/0x360
[ 1304.593064] [ T12755] ? __lock_acquire+0x497/0x2230
[ 1304.593929] [ T12755] ? __pfx_queue_attr_store+0x10/0x10
[ 1304.594787] [ T12755] ? lock_acquire+0x1b0/0x340
[ 1304.595629] [ T12755] ? sysfs_file_kobj+0x1d/0x1b0
[ 1304.596473] [ T12755] ? lock_acquire+0x1c0/0x340
[ 1304.597261] [ T12755] ? find_held_lock+0x2b/0x80
[ 1304.598107] [ T12755] ? sysfs_file_kobj+0xaf/0x1b0
[ 1304.598937] [ T12755] ? lock_release+0x1a7/0x320
[ 1304.599766] [ T12755] ? sysfs_file_kobj+0xb9/0x1b0
[ 1304.600598] [ T12755] ? sysfs_kf_write+0x61/0x160
[ 1304.601378] [ T12755] ? __pfx_sysfs_kf_write+0x10/0x10
[ 1304.602276] [ T12755] kernfs_fop_write_iter+0x3d6/0x5e0
[ 1304.603148] [ T12755] ? __pfx_kernfs_fop_write_iter+0x10/0x10
[ 1304.604048] [ T12755] vfs_write+0x523/0xf80
[ 1304.604784] [ T12755] ? arch_stack_walk+0xb3/0x100
[ 1304.605573] [ T12755] ? __pfx_vfs_write+0x10/0x10
[ 1304.606283] [ T12755] ? lock_acquire+0x1b0/0x340
[ 1304.607038] [ T12755] ? get_close_on_exec+0x1f/0x230
[ 1304.607774] [ T12755] ? get_close_on_exec+0xfc/0x230
[ 1304.608502] [ T12755] ? lock_release+0x1a7/0x320
[ 1304.609150] [ T12755] ksys_write+0xfb/0x200
[ 1304.609803] [ T12755] ? __pfx_ksys_write+0x10/0x10
[ 1304.610495] [ T12755] ? lock_release+0x1a7/0x320
[ 1304.611181] [ T12755] do_syscall_64+0x136/0x1540
[ 1304.611845] [ T12755] ? do_wp_page+0x168d/0x3610
[ 1304.612505] [ T12755] ? lock_acquire+0x1b0/0x340
[ 1304.613151] [ T12755] ? __pfx_do_wp_page+0x10/0x10
[ 1304.613803] [ T12755] ? lock_acquire+0x1b0/0x340
[ 1304.614439] [ T12755] ? do_raw_spin_lock+0x124/0x260
[ 1304.615078] [ T12755] ? lock_acquire+0x1c0/0x340
[ 1304.615697] [ T12755] ? __pfx_do_raw_spin_lock+0x10/0x10
[ 1304.616369] [ T12755] ? __pfx_pte_write+0x10/0x10
[ 1304.617022] [ T12755] ? __handle_mm_fault+0x12b2/0x1d50
[ 1304.617677] [ T12755] ? __lock_acquire+0x497/0x2230
[ 1304.618336] [ T12755] ? __pfx_css_rstat_updated+0x10/0x10
[ 1304.619065] [ T12755] ? lock_acquire+0x1b0/0x340
[ 1304.619677] [ T12755] ? count_memcg_events_mm.constprop.0+0x22/0x130
[ 1304.620438] [ T12755] ? rcu_is_watching+0x11/0xb0
[ 1304.621074] [ T12755] ? count_memcg_events+0x106/0x4a0
[ 1304.621741] [ T12755] ? find_held_lock+0x2b/0x80
[ 1304.622376] [ T12755] ? rcu_read_unlock+0x17/0x60
[ 1304.623047] [ T12755] ? lock_release+0x1a7/0x320
[ 1304.623656] [ T12755] ? find_held_lock+0x2b/0x80
[ 1304.624290] [ T12755] ? exc_page_fault+0x83/0x110
[ 1304.624926] [ T12755] ? lock_release+0x1a7/0x320
[ 1304.625553] [ T12755] ? rcu_is_watching+0x11/0xb0
[ 1304.626170] [ T12755] ? irqentry_exit+0xdd/0x6a0
[ 1304.626793] [ T12755] ? lockdep_hardirqs_on_prepare+0xce/0x1b0
[ 1304.627499] [ T12755] ? irqentry_exit+0xe2/0x6a0
[ 1304.628114] [ T12755] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 1304.628821] [ T12755] RIP: 0033:0x7f40d681277e
[ 1304.629425] [ T12755] Code: 4d 89 d8 e8 d4 bc 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa
[ 1304.631432] [ T12755] RSP: 002b:00007ffd15db4a60 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[ 1304.632364] [ T12755] RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f40d681277e
[ 1304.633275] [ T12755] RDX: 000000000000000c RSI: 000000001e02a810 RDI: 0000000000000001
[ 1304.634198] [ T12755] RBP: 00007ffd15db4a70 R08: 0000000000000000 R09: 0000000000000000
[ 1304.635127] [ T12755] R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000c
[ 1304.636044] [ T12755] R13: 000000001e02a810 R14: 00007f40d698d5c0 R15: 0000000000000000
[ 1304.636962] [ T12755] </TASK>
[ 1304.637532] [ T12755] irq event stamp: 6849
[ 1304.638170] [ T12755] hardirqs last enabled at (6861): [<ffffffffa76e6bae>] __up_console_sem+0x5e/0x70
[ 1304.639207] [ T12755] hardirqs last disabled at (6872): [<ffffffffa76e6b93>] __up_console_sem+0x43/0x70
[ 1304.640247] [ T12755] softirqs last enabled at (5936): [<ffffffffa7521b66>] __irq_exit_rcu+0x126/0x240
[ 1304.641299] [ T12755] softirqs last disabled at (5925): [<ffffffffa7521b66>] __irq_exit_rcu+0x126/0x240
[ 1304.642338] [ T12755] ---[ end trace 0000000000000000 ]---
More information about the Linux-nvme
mailing list