From: "Theodore Tso" <tytso@mit.edu>
To: Matthew Wilcox <willy@infradead.org>
Cc: linux-mm@kvack.org,
Ext4 Developers List <linux-ext4@vger.kernel.org>,
linux-xfs@vger.kernel.org
Subject: [REGRESSION] generic/127 failure caused by "mm: Use folio_next_pos()"
Date: Mon, 24 Nov 2025 13:18:11 -0600 [thread overview]
Message-ID: <20251124191811.GA26781@mac.lan> (raw)
[-- Attachment #1: Type: text/plain, Size: 1632 bytes --]
While testing the ext4 large blocksize patches I merged in
linux-next/fs-next to pick up the mm changes needed to prevent the
warnings when allocating larger blocks with GFP_NOFAIL, and I found
some unrelated regressions with three tests, including generic/127
(the other two regressions seem unrelated to this commit; I'll bisect
them separately).
Further testing found that regression occurred somewhere between
fs-current and fs-next, and I also found that it was failing not just
for ext4, but also for ext4. A git bisect run localized the failure
to this commit:
commit 60a70e61430b2d568bc5e96f629c5855ee159ace
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Fri Oct 24 18:08:18 2025 +0100
mm: Use folio_next_pos()
This is one instruction more efficient than open-coding folio_pos() +
folio_size(). It's the equivalent of (x + y) << z rather than
x << z + y << z.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://patch.msgid.link/20251024170822.1427218-11-willy@infradead.org
I then checked out linux-next (aka linux-next/master) and verified
that the problem was reproducible there, using
kvm-xfstests -c ext4/4k generic/127 --fail-loop-count 0 --kernel-build
And then when I reverted commit 60a70e61430b, the test passed. I also
checked and found that this commit was also causing generic/127 to
fail for xfs:
kvm-xfstests -c xfs/4k generic/127 --fail-loop-count 0 --kernel-build
And, with the commit reverted the problem went away.
The test logs for ext4 and xfs are attached. Willy, could you take a
look? Many thanks!!
- Ted
[-- Attachment #2: ext4-generic-127.log --]
[-- Type: text/plain, Size: 4948 bytes --]
^[c^[[?7l^[[2J^[[0mSeaBIOS (version 1.17.0-debian-1.17.0-1)
Booting from ROM..^[c^[[?7l^[[2J^[[!p^[]104\a^[[?7h[^[[0;1;31mFAILED^[[0m] Failed to start ^[[0;1;39mnbd-server.service^[[0m - Network Block Device server.
CMDLINE: "-c ext4/4k generic/127 --fail-loop-count 0"
KERNEL: kernel 6.18.0-rc6-next-20251124-xfstests #20 SMP PREEMPT_DYNAMIC Mon Nov 24 14:04:48 EST 2025 x86_64
FSTESTVER: blktests 4badb27 (Fri, 31 Oct 2025 19:53:27 +0900)
FSTESTVER: fio fio-3.41 (Fri, 5 Sep 2025 14:21:17 -0600)
FSTESTVER: fsverity v1.7 (Tue, 4 Nov 2025 17:28:17 -0800)
FSTESTVER: ima-evm-utils v1.5 (Mon, 6 Mar 2023 07:40:07 -0500)
FSTESTVER: libaio libaio-0.3.108-82-gb8eadc9 (Thu, 2 Jun 2022 13:33:11 +0200)
FSTESTVER: ltp 20250930 (Tue, 30 Sep 2025 13:53:45 +0200)
FSTESTVER: quota v4.05-77-g22ff3d9 (Tue, 2 Sep 2025 08:12:02 -0400)
FSTESTVER: util-linux v2.41.2 (Mon, 22 Sep 2025 12:56:34 +0200)
FSTESTVER: xfsprogs v6.17.0 (Mon, 20 Oct 2025 16:49:00 +0200)
FSTESTVER: xfstests v2025.11.04-12-g64e3dbda7 (Thu, 13 Nov 2025 19:58:03 -0500)
FSTESTVER: xfstests-bld gce-xfstests-202504292206-33-g3844cb58 (Thu, 13 Nov 2025 21:05:49 -0500)
FSTESTVER: zz_build-distro trixie
FSTESTCFG: "ext4/4k"
FSTESTSET: "generic/127"
FSTESTEXC: ""
FSTESTOPT: "fail_loop_count 0 aex"
MNTOPTS: ""
CPUS: "2"
MEM: "1969.56"
total used free shared buff/cache available
Mem: 1969 208 1749 0 143 1760
Swap: 0 0 0
BEGIN TEST 4k (1 test): Ext4 4k block Mon Nov 24 14:05:27 EST 2025
DEVICE: /dev/vdb
EXT_MKFS_OPTIONS: -b 4096
EXT_MOUNT_OPTIONS: -o block_validity
FSTYP -- ext4
PLATFORM -- Linux/x86_64 kvm-xfstests 6.18.0-rc6-next-20251124-xfstests #20 SMP PREEMPT_DYNAMIC Mon Nov 24 14:04:48 EST 2025
MKFS_OPTIONS -- -F -q -b 4096 /dev/vdc
MOUNT_OPTIONS -- -o acl,user_xattr -o block_validity /dev/vdc /vdc
generic/127 31s ... [14:05:28][ 3.901891] run fstests generic/127 at 2025-11-24 14:05:28
[ 4.092040] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (42) finished: extent logical block 25, len 15; IO logical block 25, len 8
[ 4.101284] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (47) finished: extent logical block 25, len 15; IO logical block 25, len 8
[ 4.125984] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (47) finished: extent logical block 35, len 9; IO logical block 39, len 1
[ 4.129140] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (47) finished: extent logical block 35, len 4; IO logical block 36, len 3
[ 4.181406] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (42) finished: extent logical block 3, len 14; IO logical block 8, len 9
[ 4.194278] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (42) finished: extent logical block 31, len 11; IO logical block 31, len 10
[ 4.198459] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (47) finished: extent logical block 3, len 14; IO logical block 8, len 9
[ 4.207676] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (50) finished: extent logical block 25, len 15; IO logical block 25, len 8
[ 4.217111] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (47) finished: extent logical block 31, len 11; IO logical block 31, len 10
[ 4.221635] EXT4-fs warning (device vdb): ext4_convert_unwritten_extents_endio:3774: Inode (41) finished: extent logical block 25, len 15; IO logical block 25, len 8
[14:05:39]- output mismatch (see /results/ext4/results-4k/generic/127.out.bad)
--- tests/generic/127.out 2025-11-13 21:05:49.000000000 -0500
+++ /results/ext4/results-4k/generic/127.out.bad 2025-11-24 14:05:39.225714867 -0500
@@ -1,7 +1,34117 @@
QA output created by 127
+/root/xfstests/ltp/fsx -q -l 262144 -o 65536 -S 191110531 -N 100000 -R -W fsx_std_nommap
+READ BAD DATA: offset = 0x11303, size = 0xf7b0, fname = /vdb/fsx_std_nommap
+OFFSET GOOD BAD RANGE
+0x14000 0x0000 0xfc9f 0x0
+operation# (mod 256) for the bad data may be 252
+0x14001 0x0000 0x9ffc 0x1
...
(Run 'diff -u /root/xfstests/tests/generic/127.out /results/ext4/results-4k/generic/127.out.bad' to see the entire diff)
Ran: generic/127
Failures: generic/127
Failed 1 of 1 tests
Xunit report: /results/ext4/results-4k/result.xml
total used free shared buff/cache available
Mem: 1969 206 1822 0 28 1762
Swap: 0 0 0
END TEST: Ext4 4k block Mon Nov 24 14:05:39 EST 2025
[-- Attachment #3: xfs-generic-127.log --]
[-- Type: text/plain, Size: 7436 bytes --]
^[c^[[?7l^[[2J^[[0mSeaBIOS (version 1.17.0-debian-1.17.0-1)
Booting from ROM..^[c^[[?7l^[[2J^[[!p^[]104\a^[[?7h[^[[0;1;31mFAILED^[[0m] Failed to start ^[[0;1;39mnbd-server.service^[[0m - Network Block Device server.
CMDLINE: "-c xfs/4k generic/127 --fail-loop-count 0"
KERNEL: kernel 6.18.0-rc6-next-20251124-xfstests #20 SMP PREEMPT_DYNAMIC Mon Nov 24 14:04:48 EST 2025 x86_64
FSTESTVER: blktests 4badb27 (Fri, 31 Oct 2025 19:53:27 +0900)
FSTESTVER: fio fio-3.41 (Fri, 5 Sep 2025 14:21:17 -0600)
FSTESTVER: fsverity v1.7 (Tue, 4 Nov 2025 17:28:17 -0800)
FSTESTVER: ima-evm-utils v1.5 (Mon, 6 Mar 2023 07:40:07 -0500)
FSTESTVER: libaio libaio-0.3.108-82-gb8eadc9 (Thu, 2 Jun 2022 13:33:11 +0200)
FSTESTVER: ltp 20250930 (Tue, 30 Sep 2025 13:53:45 +0200)
FSTESTVER: quota v4.05-77-g22ff3d9 (Tue, 2 Sep 2025 08:12:02 -0400)
FSTESTVER: util-linux v2.41.2 (Mon, 22 Sep 2025 12:56:34 +0200)
FSTESTVER: xfsprogs v6.17.0 (Mon, 20 Oct 2025 16:49:00 +0200)
FSTESTVER: xfstests v2025.11.04-12-g64e3dbda7 (Thu, 13 Nov 2025 19:58:03 -0500)
FSTESTVER: xfstests-bld gce-xfstests-202504292206-33-g3844cb58 (Thu, 13 Nov 2025 21:05:49 -0500)
FSTESTVER: zz_build-distro trixie
FSTESTCFG: "xfs/4k"
FSTESTSET: "generic/127"
FSTESTEXC: ""
FSTESTOPT: "fail_loop_count 0 aex"
MNTOPTS: ""
CPUS: "2"
MEM: "1969.56"
total used free shared buff/cache available
Mem: 1969 212 1745 0 143 1756
Swap: 0 0 0
meta-data=/dev/vdd isize=512 agcount=4, agsize=327680 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=1
= reflink=1 bigtime=1 inobtcount=1 nrext64=1
= exchange=0 metadir=0
data = bsize=4096 blocks=1310720, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1, parent=0
log =internal log bsize=4096 blocks=16384, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
= rgcount=0 rgsize=0 extents
= zoned=0 start=0 reserved=0
Discarding blocks...Done.
BEGIN TEST 4k (1 test): XFS 4k block Mon Nov 24 14:06:31 EST 2025
DEVICE: /dev/vdd
XFS_MKFS_OPTIONS: -bsize=4096
XFS_MOUNT_OPTIONS:
FSTYP -- xfs (debug)
PLATFORM -- Linux/x86_64 kvm-xfstests 6.18.0-rc6-next-20251124-xfstests #20 SMP PREEMPT_DYNAMIC Mon Nov 24 14:04:48 EST 2025
MKFS_OPTIONS -- -f -bsize=4096 /dev/vdc
MOUNT_OPTIONS -- /dev/vdc /vdc
generic/127 31s ... [14:06:33][ 6.886269] run fstests generic/127 at 2025-11-24 14:06:33
[ 7.333668] vdd: writeback error on inode 137, offset 208896, sector 2622528
[ 7.338078] XFS (vdd): Corruption of in-memory data (0x8) detected at xfs_trans_mod_sb+0x2b6/0x370 (fs/xfs/xfs_trans.c:353). Shutting down filesystem.
[ 7.341384] XFS (vdd): Please unmount the filesystem and rectify the problem(s)
[ 7.342570] XFS: Assertion failed: tp->t_blk_res >= tp->t_blk_res_used, file: fs/xfs/xfs_trans.c, line: 120
[ 7.344123] ------------[ cut here ]------------
[ 7.344851] WARNING: fs/xfs/xfs_message.c:104 at assfail+0x33/0x3a, CPU#1: kworker/1:0/23
[ 7.346172] CPU: 1 UID: 0 PID: 23 Comm: kworker/1:0 Not tainted 6.18.0-rc6-next-20251124-xfstests #20 PREEMPT(none)
[ 7.347861] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
[ 7.349936] Workqueue: xfs-conv/vdd xfs_end_io
[ 7.350759] RIP: 0010:assfail+0x33/0x3a
[ 7.351341] Code: 49 89 d0 41 89 c9 48 c7 c2 d8 18 a8 82 48 89 f1 48 89 fe 48 c7 c7 e4 0c b0 82 e8 b8 fd ff ff 80 3d 59 6d ba 01 00 74 02 0f 0b <0f> 0b e9 41 da ed ff 48 8d 45 10 48 89 e2 48 89 de 4c 89 34 24 48
[ 7.354327] RSP: 0018:ffa00000000cbc00 EFLAGS: 00010246
[ 7.355161] RAX: 0000000000000000 RBX: ff11000011dafbc8 RCX: 000000007fffffff
[ 7.356328] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff82b00ce4
[ 7.357522] RBP: ff11000011dafd98 R08: 0000000000000000 R09: 000000000000000a
[ 7.358681] R10: 000000000000000a R11: 0fffffffffffffff R12: 000000050002f3f8
[ 7.359835] R13: 0000000000039a46 R14: ff11000011dafe68 R15: ff11000011dafe68
[ 7.361031] FS: 0000000000000000(0000) GS:ff110000fa430000(0000) knlGS:0000000000000000
[ 7.362325] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7.363273] CR2: 00007fbb37aaa350 CR3: 0000000002c2e003 CR4: 0000000000771ef0
[ 7.364422] PKRU: 55555554
[ 7.364872] Call Trace:
[ 7.365309] <TASK>
[ 7.365671] xfs_trans_dup+0x16e/0x1c0
[ 7.366287] xfs_trans_roll+0x2e/0xd0
[ 7.366906] xfs_defer_trans_roll+0x53/0x130
[ 7.367608] ? srso_alias_return_thunk+0x5/0xfbef5
[ 7.368393] xfs_defer_finish_noroll+0x2cd/0x500
[ 7.369419] xfs_trans_commit+0x4c/0x70
[ 7.370486] ? xfs_iomap_write_unwritten+0x180/0x320
[ 7.371227] xfs_iomap_write_unwritten+0xce/0x320
[ 7.371932] xfs_end_ioend+0x207/0x2b0
[ 7.372517] xfs_end_io+0xb5/0x100
[ 7.373046] process_one_work+0x18c/0x360
[ 7.373697] worker_thread+0x268/0x3b0
[ 7.374265] ? __pfx_worker_thread+0x10/0x10
[ 7.374910] kthread+0x10a/0x230
[ 7.375422] ? __pfx_kthread+0x10/0x10
[ 7.375989] ? __pfx_kthread+0x10/0x10
[ 7.376577] ret_from_fork+0x95/0x110
[ 7.377142] ? __pfx_kthread+0x10/0x10
[ 7.377709] ret_from_fork_asm+0x1a/0x30
[ 7.378303] </TASK>
[ 7.378663] ---[ end trace 0000000000000000 ]---
[ 7.379365] vdd: writeback error on inode 132, offset 184320, sector 888
_check_xfs_filesystem: filesystem on /dev/vdd has dirty log
(see /results/xfs/results-4k/generic/127.full for details)
_check_xfs_filesystem: filesystem on /dev/vdd is inconsistent (r)
(see /results/xfs/results-4k/generic/127.full for details)
Trying to repair broken TEST_DEV file system
_check_dmesg: something found in dmesg (see /results/xfs/results-4k/generic/127.dmesg)
[14:06:34]- output mismatch (see /results/xfs/results-4k/generic/127.out.bad)
--- tests/generic/127.out 2025-11-13 21:05:49.000000000 -0500
+++ /results/xfs/results-4k/generic/127.out.bad 2025-11-24 14:06:34.037856472 -0500
@@ -1,7 +1,25950 @@
QA output created by 127
-All 100000 operations completed A-OK!
-All 100000 operations completed A-OK!
-All 100000 operations completed A-OK!
-All 100000 operations completed A-OK!
-All 100000 operations completed A-OK!
-All 100000 operations completed A-OK!
...
(Run 'diff -u /root/xfstests/tests/generic/127.out /results/xfs/results-4k/generic/127.out.bad' to see the entire diff)
Ran: generic/127
Failures: generic/127
Failed 1 of 1 tests
Xunit report: /results/xfs/results-4k/result.xml
total used free shared buff/cache available
Mem: 1969 309 1719 0 30 1660
Swap: 0 0 0
END TEST: XFS 4k block Mon Nov 24 14:06:34 EST 2025
next reply other threads:[~2025-11-24 19:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-24 19:18 Theodore Tso [this message]
2025-11-24 19:20 ` [REGRESSION] generic/127 failure caused by "mm: Use folio_next_pos()" Matthew Wilcox
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