Zorro Lang reported the following lockdep splat:
"While running fstests xfs/556 on kernel 7.0.0-rc4+ (HEAD=04a9f1766954),
a lockdep warning was triggered indicating an inconsistent lock state
for sb->s_type->i_lock_key.
"The deadlock might occur because iomap_read_end_io (called from a
hardware interrupt completion path) invokes fserror_report, which then
calls igrab. igrab attempts to acquire the i_lock spinlock. However,
the i_lock is frequently acquired in process context with interrupts
enabled. If an interrupt occurs while a process holds the i_lock, and
that interrupt handler calls fserror_report, the system deadlocks.
"I hit this warning several times by running xfs/556 (mostly) or
generic/648 on xfs. More details refer to below console log."
along with this dmesg, for which I've cleaned up the stacktraces:
run fstests xfs/556 at 2026-03-18 20:05:30
XFS (sda3): Mounting V5 Filesystem 396e9164-c45a-4e05-be9d-b38c2c5c6477
XFS (sda3): Ending clean mount
XFS (sda3): Unmounting Filesystem 396e9164-c45a-4e05-be9d-b38c2c5c6477
XFS (sda3): Mounting V5 Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
XFS (sda3): Ending clean mount
XFS (sda3): Unmounting Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
XFS (dm-0): Mounting V5 Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
XFS (dm-0): Ending clean mount
device-mapper: table: 253:0: adding target device (start sect 209 len 1) caused an alignment inconsistency
device-mapper: table: 253:0: adding target device (start sect 210 len 62914350) caused an alignment inconsistency
buffer_io_error: 6 callbacks suppressed
Buffer I/O error on dev dm-0, logical block 209, async page read
Buffer I/O error on dev dm-0, logical block 209, async page read
XFS (dm-0): Unmounting Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
XFS (dm-0): Mounting V5 Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
XFS (dm-0): Ending clean mount
================================
WARNING: inconsistent lock state
7.0.0-rc4+ #1 Tainted: G S W
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
od/2368602 [HC1[1]:SC0[0]:HE0:SE1] takes:
ff1100069f2b4a98 (&sb->s_type->i_lock_key#31){?.+.}-{3:3}, at: igrab+0x28/0x1a0
{HARDIRQ-ON-W} state was registered at:
__lock_acquire+0x40d/0xbd0
lock_acquire.part.0+0xbd/0x260
_raw_spin_lock+0x37/0x80
unlock_new_inode+0x66/0x2a0
xfs_iget+0x67b/0x7b0 [xfs]
xfs_mountfs+0xde4/0x1c80 [xfs]
xfs_fs_fill_super+0xe86/0x17a0 [xfs]
get_tree_bdev_flags+0x312/0x590
vfs_get_tree+0x8d/0x2f0
vfs_cmd_create+0xb2/0x240
__do_sys_fsconfig+0x3d8/0x9a0
do_syscall_64+0x13a/0x1520
entry_SYSCALL_64_after_hwframe+0x76/0x7e
irq event stamp: 3118
hardirqs last enabled at (3117): [<ffffffffb54e4ad8>] _raw_spin_unlock_irq+0x28/0x50
hardirqs last disabled at (3118): [<ffffffffb54b84c9>] common_interrupt+0x19/0xe0
softirqs last enabled at (3040): [<ffffffffb290ca28>] handle_softirqs+0x6b8/0x950
softirqs last disabled at (3023): [<ffffffffb290ce4d>] __irq_exit_rcu+0xfd/0x250
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&sb->s_type->i_lock_key#31);
<Interrupt>
lock(&sb->s_type->i_lock_key#31);
*** DEADLOCK ***
1 lock held by od/2368602:
#0: ff1100069f2b4b58 (&sb->s_type->i_mutex_key#19){++++}-{4:4}, at: xfs_ilock+0x324/0x4b0 [xfs]
stack backtrace:
CPU: 15 UID: 0 PID: 2368602 Comm: od Kdump: loaded Tainted: G S W 7.0.0-rc4+ #1 PREEMPT(full)
Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN
Hardware name: Dell Inc. PowerEdge R660/0R5JJC, BIOS 2.1.5 03/14/2024
Call Trace:
<IRQ>
dump_stack_lvl+0x6f/0xb0
print_usage_bug.part.0+0x230/0x2c0
mark_lock_irq+0x3ce/0x5b0
mark_lock+0x1cb/0x3d0
mark_usage+0x109/0x120
__lock_acquire+0x40d/0xbd0
lock_acquire.part.0+0xbd/0x260
_raw_spin_lock+0x37/0x80
igrab+0x28/0x1a0
fserror_report+0x127/0x2d0
iomap_finish_folio_read+0x13c/0x280
iomap_read_end_io+0x10e/0x2c0
clone_endio+0x37e/0x780 [dm_mod]
blk_update_request+0x448/0xf00
scsi_end_request+0x74/0x750
scsi_io_completion+0xe9/0x7c0
_scsih_io_done+0x6ba/0x1ca0 [mpt3sas]
_base_process_reply_queue+0x249/0x15b0 [mpt3sas]
_base_interrupt+0x95/0xe0 [mpt3sas]
__handle_irq_event_percpu+0x1f0/0x780
handle_irq_event+0xa9/0x1c0
handle_edge_irq+0x2ef/0x8a0
__common_interrupt+0xa0/0x170
common_interrupt+0xb7/0xe0
</IRQ>
<TASK>
asm_common_interrupt+0x26/0x40
RIP: 0010:_raw_spin_unlock_irq+0x2e/0x50
Code: 0f 1f 44 00 00 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 b5 73 5e fd 48 89 df e8 ed e2 5e fd e8 08 78 8f fd fb bf 01 00 00 00 <e8> 8d 56 4d fd 65 8b 05 46 d5 1d 03 85 c0 74 06 5b c3 cc cc cc cc
RSP: 0018:ffa0000027d07538 EFLAGS: 00000206
RAX: 0000000000000c2d RBX: ffffffffb6614bc8 RCX: 0000000000000080
RDX: 0000000000000000 RSI: ffffffffb6306a01 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffffb75efc67 R11: 0000000000000001 R12: ff1100015ada0000
R13: 0000000000000083 R14: 0000000000000002 R15: ffffffffb6614c10
folio_wait_bit_common+0x407/0x780
filemap_update_page+0x8e7/0xbd0
filemap_get_pages+0x904/0xc50
filemap_read+0x320/0xc20
xfs_file_buffered_read+0x2aa/0x380 [xfs]
xfs_file_read_iter+0x263/0x4a0 [xfs]
vfs_read+0x6cb/0xb70
ksys_read+0xf9/0x1d0
do_syscall_64+0x13a/0x1520
Zorro's diagnosis makes sense, so the solution is to kick the failed
read handling to a workqueue much like we added for writeback ioends in
commit 294f54f849 ("fserror: fix lockdep complaint when igrabbing
inode").
Cc: Zorro Lang <zlang@redhat.com>
Link: https://lore.kernel.org/linux-xfs/20260319194303.efw4wcu7c4idhthz@doltdoltdolt/
Fixes: a9d573ee88 ("iomap: report file I/O errors to the VFS")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Link: https://patch.msgid.link/20260323210017.GL6223@frogsfrogsfrogs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
f621324dfb