Just to remind, running xfstests/generic/273 could trigger the lockdep
deadlock warning.
--
Su
On 2019/10/23 9:22 AM, Darrick J. Wong wrote:
On Tue, Oct 22, 2019 at 03:24:22PM -0700, Andrew Morton wrote:
(switched to email. Please respond via emailed reply-to-all, not via the
bugzilla web interface).
On Tue, 22 Oct 2019 09:02:22 +0000 bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote:
https://bugzilla.kernel.org/show_bug.cgi?id=205135
--- Comment #7 from goodmirek@xxxxxxxxxxxxx ---
Everyone who uses a swapfile on XFS filesystem seem affected by this hang up.
Not sure about other filesystems, I did not have a chance to test it elsewhere.
This unreproduced bot crash could be related:
https://lore.kernel.org/linux-mm/20190910071804.2944-1-hdanton@xxxxxxxx/
Thanks. Might be core MM, might be XFS, might be Fedora.
Hilf, does your patch look related? That seems to have gone quiet?
Should we progress Tetsuo's patch?
Hmm...
Oct 09 15:44:52 kernel: Linux version 5.4.0-0.rc1.git1.1.fc32.x86_64 (mockbuild@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) (gcc version 9.2.1 20190827 (Red Hat 9.2.1-1) (GCC)) #1 SMP Fri Oct 4 14:57:23 UTC 2019
...istr 5.4-rc1 had some writeback bugs in it...
-> #1 (fs_reclaim){+.+.}:
Oct 09 13:47:08 kernel: fs_reclaim_acquire.part.0+0x25/0x30
Oct 09 13:47:08 kernel: __kmalloc+0x4f/0x330
Oct 09 13:47:08 kernel: kmem_alloc+0x83/0x1a0 [xfs]
Oct 09 13:47:08 kernel: kmem_alloc_large+0x3c/0x100 [xfs]
Oct 09 13:47:08 kernel: xfs_attr_copy_value+0x5d/0xa0 [xfs]
Oct 09 13:47:08 kernel: xfs_attr_get+0xe7/0x1d0 [xfs]
Oct 09 13:47:08 kernel: xfs_get_acl+0xad/0x1e0 [xfs]
Oct 09 13:47:08 kernel: get_acl+0x81/0x110
Oct 09 13:47:08 kernel: posix_acl_create+0x58/0x160
Oct 09 13:47:08 kernel: xfs_generic_create+0x7e/0x2f0 [xfs]
Oct 09 13:47:08 kernel: lookup_open+0x5bd/0x820
Oct 09 13:47:08 kernel: path_openat+0x340/0xcb0
Oct 09 13:47:08 kernel: do_filp_open+0x91/0x100
Oct 09 13:47:08 kernel: do_sys_open+0x184/0x220
Oct 09 13:47:08 kernel: do_syscall_64+0x5c/0xa0
Oct 09 13:47:08 kernel: entry_SYSCALL_64_after_hwframe+0x49/0xbe
That's XFS trying to allocate memory to load an acl off disk, only it
looks this thread does a MAYFAIL allocation. It's a GFP_FS (since we
don't set KM_NOFS) allocation so we recurse into fs reclaim, and the
ACL-getter has locked the inode (which is probably why lockdep
triggers). I wonder if that's really a deadlock vs. just super-slow
behavior, but otoh I don't think we're supposed to allow reclaim to jump
into the filesystems when the fs has locks held.
That kmem_alloc_large should probably be changed to KM_NOFS. Dave?
--D
