Re: generic/753 crash with LARP

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Feb 02, 2026 at 06:28:53AM -0800, Christoph Hellwig wrote:
> I've seen a few crashed during xfstests where generic/753 crashed during
> attr log recovery.  They never reproduced when running the test
> standalone in the loop, which made me realize that normally the
> test does not even hit attr log recovery.  Forcing using the attr log
> items using:
> 
> echo 1 > /sys/fs/xfs/debug/larp
> 
> Now makes it crash immediately for me.  I plan to separately look why
> LARP is enabled during my -g auto run, probably some issue with the
> actual LARP tests, but for now here is the trace.  Sending this to
> Darrick as I think he touched that area last and might have ideas.

Huh, that's interesting.  I still get other weird failures in g/753 like
attr fork block 0 containing random garbage, but I've not seen this one
yet.

I suspect what's happening is that the attr intent code might have
finished writing the new attr and cleared incomplete but didn't manage
to write the attrd log item to disk before the fs went down.

The strange thing that I think I'm seeing is a dirty log with an ondisk
transaction that ends with the updates needed to allocate and map a new
block into the attr fork at fileoff 0, but oddly is missing the buffer
log item to set the contents of the new block 0 to an attr leaf block.

But it takes a good hour of pounding before that happens, so it's hard
even to add debugging to chase this down.

--D

> [   40.121475] XFS (dm-0): Mounting V5 Filesystem 82ccfb3f-c733-4297-a560-0b583af89968
> [   40.325118] XFS (dm-0): Starting recovery (logdev: internal)
> [   40.947262] XFS: Assertion failed: (entry->flags & XFS_ATTR_INCOMPLETE) == 0, file: fs/xfs/libxfs/xfs_attr_leaf.c, line: 2996
> [   40.947950] ------------[ cut here ]------------
> [   40.948205] kernel BUG at fs/xfs/xfs_message.c:102!
> [   40.948500] Oops: invalid opcode: 0000 [#1] SMP NOPTI
> [   40.948932] CPU: 0 UID: 0 PID: 4585 Comm: mount Not tainted 6.19.0-rc6+ #3467 PREEMPT(full) 
> [   40.949483] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
> [   40.950048] RIP: 0010:assfail+0x2c/0x35
> [   40.950252] Code: 40 d6 49 89 d0 41 89 c9 48 c7 c2 58 ed f8 82 48 89 f1 48 89 fe 48 c7 c7 d6 33 02 83 e8 fd fd ff ff 80 3d 7e ce 84 02 00 74 02 <0f> 0b 0f 0b c3 cc cc cc cc 48 8d 45 10 48 89 e2 4c 89 e6 48 89 1c
> [   40.950871] RSP: 0018:ffffc90006dc3a68 EFLAGS: 00010202
> [   40.950871] RAX: 0000000000000000 RBX: ffff8881130bd158 RCX: 000000007fffffff
> [   40.950871] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff830233d6
> [   40.950871] RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000000a
> [   40.950871] R10: 000000000000000a R11: 0fffffffffffffff R12: ffff88811ac9c000
> [   40.950871] R13: ffff88811ac9c0d0 R14: ffff888117b8e300 R15: ffff8881130bd100
> [   40.950871] FS:  00007f35a3087840(0000) GS:ffff8884eb58a000(0000) knlGS:0000000000000000
> [   40.950871] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   40.950871] CR2: 00007fff920deed8 CR3: 000000012821e004 CR4: 0000000000770ef0
> [   40.950871] PKRU: 55555554
> [   40.950871] Call Trace:
> [   40.950871]  <TASK>
> [   40.950871]  xfs_attr3_leaf_setflag+0x188/0x1e0
> [   40.950871]  xfs_attr_set_iter+0x46d/0xbb0
> [   40.950871]  xfs_attr_finish_item+0x48/0x110
> [   40.950871]  xfs_defer_finish_one+0xfd/0x2a0
> [   40.950871]  xlog_recover_finish_intent+0x68/0x80
> [   40.950871]  xfs_attr_recover_work+0x360/0x5a0
> [   40.950871]  xfs_defer_finish_recovery+0x1f/0x90
> [   40.950871]  xlog_recover_process_intents+0x9f/0x2b0
> [   40.950871]  ? _raw_spin_unlock_irqrestore+0x1d/0x40
> [   40.950871]  ? debug_object_activate+0x1ec/0x250
> [   40.950871]  xlog_recover_finish+0x46/0x320
> [   40.950871]  xfs_log_mount_finish+0x16a/0x1c0
> [   40.950871]  xfs_mountfs+0x52e/0xa60
> [   40.950871]  ? xfs_mru_cache_create+0x179/0x1c0
> [   40.950871]  xfs_fs_fill_super+0x669/0xa30
> [   40.950871]  ? __pfx_xfs_fs_fill_super+0x10/0x10
> [   40.950871]  get_tree_bdev_flags+0x12f/0x1d0
> [   40.950871]  vfs_get_tree+0x24/0xd0
> [   40.950871]  vfs_cmd_create+0x54/0xd0
> [   40.950871]  __do_sys_fsconfig+0x4f6/0x6b0
> [   40.950871]  do_syscall_64+0x50/0x2a0
> [   40.950871]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> [   40.950871] RIP: 0033:0x7f35a32ac4aa
> [   40.950871] Code: 73 01 c3 48 8b 0d 4e 59 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 af 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1e 59 0d 00 f7 d8 64 89 01 48
> [   40.950871] RSP: 002b:00007ffce01ac698 EFLAGS: 00000246 ORIG_RAX: 00000000000001af
> [   40.950871] RAX: ffffffffffffffda RBX: 00005625531e3ad0 RCX: 00007f35a32ac4aa
> [   40.950871] RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003
> [   40.950871] RBP: 00005625531e4bf0 R08: 0000000000000000 R09: 0000000000000000
> [   40.950871] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> [   40.950871] R13: 00007f35a343e580 R14: 00007f35a344026c R15: 00007f35a3425a23
> [   40.950871]  </TASK>
> [   40.950871] Modules linked in:
> [   40.964577] ---[ end trace 0000000000000000 ]---
> [   40.965044] RIP: 0010:assfail+0x2c/0x35
> [   40.965274] Code: 40 d6 49 89 d0 41 89 c9 48 c7 c2 58 ed f8 82 48 89 f1 48 89 fe 48 c7 c7 d6 33 02 83 e8 fd fd ff ff 80 3d 7e ce 84 02 00 74 02 <0f> 0b 0f 0b c3 cc cc cc cc 48 8d 45 10 48 89 e2 4c 89 e6 48 89 1c
> [   40.966296] RSP: 0018:ffffc90006dc3a68 EFLAGS: 00010202
> [   40.966588] RAX: 0000000000000000 RBX: ffff8881130bd158 RCX: 000000007fffffff
> [   40.967151] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff830233d6
> [   40.967546] RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000000a
> [   40.967947] R10: 000000000000000a R11: 0fffffffffffffff R12: ffff88811ac9c000
> [   40.968322] R13: ffff88811ac9c0d0 R14: ffff888117b8e300 R15: ffff8881130bd100
> [   40.968687] FS:  00007f35a3087840(0000) GS:ffff8884eb58a000(0000) knlGS:0000000000000000
> [   40.969101] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   40.969437] CR2: 00007f9fd47ad3f0 CR3: 000000012821e004 CR4: 0000000000770ef0
> [   40.969806] PKRU: 55555554
>