On Fri, Oct 18, 2024 at 04:59:01PM +0200, Jan Kara wrote:
> Currently we clear BH_New bit in case of error and also in the standard
> ext4_write_end() handler (in block_commit_write()). However
> ext4_journalled_write_end() misses this clearing and thus we are leaving
> stale BH_New bits behind. Generally ext4_block_write_begin() clears
> these bits before any harm can be done but in case blocksize < pagesize
> and we hit some error when processing a page with these stale bits,
> we'll try to zero buffers with these stale BH_New bits and jbd2 will
> complain (as buffers were not prepared for writing in this transaction).
> Fix the problem by clearing BH_New bits in ext4_journalled_write_end()
> and WARN if ext4_block_write_begin() sees stale BH_New bits.
>
> Reported-and-tested-by: Baolin Liu <liubaolin@xxxxxxxxxx>
> Reported-and-tested-by: Zhi Long <longzhi@xxxxxxxxxxxxxx>
> Fixes: 3910b513fcdf ("ext4: persist the new uptodate buffers in ext4_journalled_zero_new_buffers")
> Signed-off-by: Jan Kara <jack@xxxxxxx>
This patch is causing quite a lot of regressions:
ext4/adv: 569 tests, 36 failures, 61 skipped, 6510 seconds
Failures: ext4/307 generic/069 generic/079 generic/082 generic/130
generic/131 generic/219 generic/230 generic/231 generic/232
generic/233 generic/234 generic/235 generic/241 generic/244
generic/270 generic/280 generic/355 generic/379 generic/381
generic/382 generic/400 generic/422 generic/464 generic/566
generic/571 generic/572 generic/587 generic/600 generic/601
generic/681 generic/682 generic/691
This appears to be caused by inline data, so a quick reproducer for
bisection purposes was:
kvm-xfststs -c ext4/inline ext4/307
Attached below please find the warning which is triggering the
"_check_dmesg: something found in dmesg" test failure.
I suspect this should be fairly easy to fix, but I'm going to drop it
from my tree for now.
- Ted
WARNING: CPU: 0 PID: 2473 at fs/ext4/inode.c:1059 ext4_block_write_begin+0x2f9/0x470
CPU: 0 UID: 0 PID: 2473 Comm: md5sum Not tainted 6.12.0-rc4-xfstests-00028-g9af1fa3b363b #437
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:ext4_block_write_begin+0x2f9/0x470
Code: 40 01 89 44 24 34 e9 c4 fe ff ff 49 8b 01 a8 08 0f 84 b9 fe ff ff 48 8b 03 a8 01 0f 85 ae fe ff ff f0 80 0b 01 e9 a5 fe ff ff <0f> 0b f0 80 23 df e9 12 fe ff ff 0f b7 10 66 81 e2 00 f0 66 81 fa
RSP: 0018:ffffc90003187cd8 EFLAGS: 00010202
RAX: 0000000000000133 RBX: ffff888007c70270 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000001000 RDI: ffff888007d39c88
RBP: 0000000000001000 R08: ffffffff81466c60 R09: ffffea00003b5940
R10: 0000000000000000 R11: 00000000000000c0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000001000 R15: 0000000000000000
FS: 00007f337bc40740(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562a05dff538 CR3: 000000000c9ba005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<TASK>
? show_trace_log_lvl+0x1a5/0x2e0
? show_trace_log_lvl+0x1a5/0x2e0
? ext4_da_write_begin+0x153/0x270
? ext4_block_write_begin+0x2f9/0x470
? __warn.cold+0x8e/0xe8
? ext4_block_write_begin+0x2f9/0x470
? report_bug+0x123/0x190
? handle_bug+0x53/0x90
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? __pfx_ext4_da_get_block_prep+0x10/0x10
? ext4_block_write_begin+0x2f9/0x470
? ext4_block_write_begin+0x77/0x470
? __pfx_ext4_da_get_block_prep+0x10/0x10
ext4_da_write_begin+0x153/0x270
generic_perform_write+0xd7/0x290
ext4_buffered_write_iter+0x64/0x100
vfs_write+0x277/0x450
ksys_write+0x6d/0xf0
do_syscall_64+0x4b/0x110
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f337bd3b240
Code: 40 00 48 8b 15 c1 9b 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d a1 23 0e 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007fff53588b08 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000043 RCX: 00007f337bd3b240
RDX: 0000000000000043 RSI: 0000562a05df54d0 RDI: 0000000000000001
RBP: 0000562a05df54d0 R08: 00007f337bddd4e0 R09: 0000000000000078
R10: 00007fff53588a86 R11: 0000000000000202 R12: 0000000000000043
R13: 00007f337be16760 R14: 0000000000000043 R15: 00007f337be119e0
</TASK>
---[ end trace 0000000000000000 ]---
