linux-kernel - [PATCH 2/2] xfs: take a breath in xfsaild()

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Message-ID: <20260205082621.2259895-3-alexjlzheng@tencent.com>
Date: Thu,  5 Feb 2026 16:26:21 +0800
From: alexjlzheng@...il.com
To: cem@...nel.org
Cc: linux-xfs@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Jinliang Zheng <alexjlzheng@...cent.com>
Subject: [PATCH 2/2] xfs: take a breath in xfsaild()

From: Jinliang Zheng <alexjlzheng@...cent.com>

We noticed a softlockup like:

  crash> bt
  PID: 5153     TASK: ffff8960a7ca0000  CPU: 115  COMMAND: "xfsaild/dm-4"
   #0 [ffffc9001b1d4d58] machine_kexec at ffffffff9b086081
   #1 [ffffc9001b1d4db8] __crash_kexec at ffffffff9b20817a
   #2 [ffffc9001b1d4e78] panic at ffffffff9b107d8f
   #3 [ffffc9001b1d4ef8] watchdog_timer_fn at ffffffff9b243511
   #4 [ffffc9001b1d4f28] __hrtimer_run_queues at ffffffff9b1e62ff
   #5 [ffffc9001b1d4f80] hrtimer_interrupt at ffffffff9b1e73d4
   #6 [ffffc9001b1d4fd8] __sysvec_apic_timer_interrupt at ffffffff9b07bb29
   #7 [ffffc9001b1d4ff0] sysvec_apic_timer_interrupt at ffffffff9bd689f9
  --- <IRQ stack> ---
   #8 [ffffc90031cd3a18] asm_sysvec_apic_timer_interrupt at ffffffff9be00e86
      [exception RIP: part_in_flight+47]
      RIP: ffffffff9b67960f  RSP: ffffc90031cd3ac8  RFLAGS: 00000282
      RAX: 00000000000000a9  RBX: 00000000000c4645  RCX: 00000000000000f5
      RDX: ffffe89fffa36fe0  RSI: 0000000000000180  RDI: ffffffff9d1ae260
      RBP: ffff898083d30000   R8: 00000000000000a8   R9: 0000000000000000
      R10: ffff89808277d800  R11: 0000000000001000  R12: 0000000101a7d5be
      R13: 0000000000000000  R14: 0000000000001001  R15: 0000000000001001
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   #9 [ffffc90031cd3ad8] update_io_ticks at ffffffff9b6602e4
  #10 [ffffc90031cd3b00] bdev_start_io_acct at ffffffff9b66031b
  #11 [ffffc90031cd3b20] dm_io_acct at ffffffffc18d7f98 [dm_mod]
  #12 [ffffc90031cd3b50] dm_submit_bio_remap at ffffffffc18d8195 [dm_mod]
  #13 [ffffc90031cd3b70] dm_split_and_process_bio at ffffffffc18d9799 [dm_mod]
  #14 [ffffc90031cd3be0] dm_submit_bio at ffffffffc18d9b07 [dm_mod]
  #15 [ffffc90031cd3c20] __submit_bio at ffffffff9b65f61c
  #16 [ffffc90031cd3c38] __submit_bio_noacct at ffffffff9b65f73e
  #17 [ffffc90031cd3c80] xfs_buf_ioapply_map at ffffffffc23df4ea [xfs]
  #18 [ffffc90031cd3ce0] _xfs_buf_ioapply at ffffffffc23df64f [xfs]
  #19 [ffffc90031cd3d50] __xfs_buf_submit at ffffffffc23df7b8 [xfs]
  #20 [ffffc90031cd3d70] xfs_buf_delwri_submit_buffers at ffffffffc23dffbd [xfs]
  #21 [ffffc90031cd3df8] xfsaild_push at ffffffffc24268e5 [xfs]
  #22 [ffffc90031cd3eb8] xfsaild at ffffffffc2426f88 [xfs]
  #23 [ffffc90031cd3ef8] kthread at ffffffff9b1378fc
  #24 [ffffc90031cd3f30] ret_from_fork at ffffffff9b042dd0
  #25 [ffffc90031cd3f50] ret_from_fork_asm at ffffffff9b007e2b

This patch adds cond_resched() to avoid softlockups similar to the one
described above.

Signed-off-by: Jinliang Zheng <alexjlzheng@...cent.com>
---
 fs/xfs/xfs_buf.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 47edf3041631..f1f8595d5e40 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -2026,6 +2026,8 @@ xfs_buf_delwri_submit_nowait(
 		bp->b_flags |= XBF_ASYNC;
 		xfs_buf_list_del(bp);
 		xfs_buf_submit(bp);
+
+		cond_resched();
 	}
 	blk_finish_plug(&plug);
 
-- 
2.49.0