Re: next-20250626: WARNING fs jbd2 transaction.c start_this_handle with ARM64_64K_PAGES

[Naresh Kamboju]

On Thu, 26 Jun 2025 at 19:23, Zhang Yi <yi.zhang@xxxxxxxxxxxxxxx> wrote:
>
> Hi, Naresh!
>
> On 2025/6/26 20:31, Naresh Kamboju wrote:
> > Regressions noticed on arm64 devices while running LTP syscalls mmap16
> > test case on the Linux next-20250616..next-20250626 with the extra build
> > config fragment CONFIG_ARM64_64K_PAGES=y the kernel warning noticed.
> >
> > Not reproducible with 4K page size.
> >
> > Test environments:
> > - Dragonboard-410c
> > - Juno-r2
> > - rk3399-rock-pi-4b
> > - qemu-arm64
> >
> > Regression Analysis:
> > - New regression? Yes
> > - Reproducibility? Yes
> >
> > Test regression: next-20250626 LTP mmap16 WARNING fs jbd2
> > transaction.c start_this_handle
> >
> > Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
>
> Thank you for the report. The block size for this test is 1 KB, so I
> suspect this is the issue with insufficient journal credits that we
> are going to resolve.

I have applied your patch set [1] and tested and the reported
regressions did not fix.
Am I missing anything ?

[1] https://lore.kernel.org/linux-ext4/20250611111625.1668035-1-yi.zhang@xxxxxxxxxxxxxxx/

>
> Thanks,
> Yi.

- Naresh

> >
> > ## Test log
> > <6>[   89.498969] loop0: detected capacity change from 0 to 614400
> > <3>[   89.609561] operation not supported error, dev loop0, sector
> > 20352 op 0x9:(WRITE_ZEROES) flags 0x20000800 phys_seg 0 prio class 0
> > <6>[   89.707795] EXT4-fs (loop0): mounted filesystem
> > 6786a191-5e0d-472b-8bce-4714e1a4fb44 r/w with ordered data mode. Quota
> > mode: none.
> > <3>[   90.023985] JBD2: kworker/u8:2 wants too many credits
> > credits:416 rsv_credits:21 max:334
> > <4>[   90.024973] ------------[ cut here ]------------
> > <4>[ 90.025062] WARNING: fs/jbd2/transaction.c:334 at
> > start_this_handle+0x4c0/0x4e0, CPU#0: 2/42
> > <4>[   90.026661] Modules linked in: btrfs blake2b_generic xor
> > xor_neon raid6_pq zstd_compress sm3_ce sha3_ce fuse drm backlight
> > ip_tables x_tables
> > <4>[   90.027952] CPU: 0 UID: 0 PID: 42 Comm: kworker/u8:2 Not tainted
> > 6.16.0-rc3-next-20250626 #1 PREEMPT
> > <4>[   90.029043] Hardware name: linux,dummy-virt (DT)
> > <4>[   90.029524] Workqueue: writeback wb_workfn (flush-7:0)
> > <4>[   90.030050] pstate: 63402009 (nZCv daif +PAN -UAO +TCO +DIT
> > -SSBS BTYPE=--)
> > <4>[ 90.030311] pc : start_this_handle (fs/jbd2/transaction.c:334
> > (discriminator 1))
> > <4>[ 90.030481] lr : start_this_handle (fs/jbd2/transaction.c:334
> > (discriminator 1))
> > <4>[   90.030656] sp : ffffc000805cb650
> > <4>[   90.030785] x29: ffffc000805cb690 x28: fff00000dd1f5000 x27:
> > ffffde2ec0272000
> > <4>[   90.031097] x26: 00000000000001a0 x25: 0000000000000015 x24:
> > 0000000000000002
> > <4>[   90.031360] x23: 0000000000000015 x22: 0000000000000c40 x21:
> > 0000000000000008
> > <4>[   90.031618] x20: fff00000c231da78 x19: fff00000c231da78 x18:
> > 0000000000000000
> > <4>[   90.031875] x17: 0000000000000000 x16: 0000000000000000 x15:
> > 0000000000000000
> > <4>[   90.032859] x14: 0000000000000000 x13: 00000000ffffffff x12:
> > 0000000000000000
> > <4>[   90.033225] x11: 0000000000000000 x10: ffffde2ebfba8bd0 x9 :
> > ffffde2ebd34e944
> > <4>[   90.033607] x8 : ffffc000805cb278 x7 : 0000000000000000 x6 :
> > 0000000000000001
> > <4>[   90.033971] x5 : ffffde2ebfb29000 x4 : ffffde2ebfb293d0 x3 :
> > 0000000000000000
> > <4>[   90.034294] x2 : 0000000000000000 x1 : fff00000c04dc080 x0 :
> > 000000000000004c
> > <4>[   90.034772] Call trace:
> > <4>[ 90.035068] start_this_handle (fs/jbd2/transaction.c:334
> > (discriminator 1)) (P)
> > <4>[ 90.035366] jbd2__journal_start (fs/jbd2/transaction.c:501)
> > <4>[ 90.035586] __ext4_journal_start_sb (fs/ext4/ext4_jbd2.c:117)
> > <4>[ 90.035807] ext4_do_writepages (fs/ext4/ext4_jbd2.h:242
> > fs/ext4/inode.c:2846)
> > <4>[ 90.036004] ext4_writepages (fs/ext4/inode.c:2953)
> > <4>[ 90.036233] do_writepages (mm/page-writeback.c:2636)
> > <4>[ 90.036406] __writeback_single_inode (fs/fs-writeback.c:1680)
> > <4>[ 90.036616] writeback_sb_inodes (fs/fs-writeback.c:1978)
> > <4>[ 90.036891] wb_writeback (fs/fs-writeback.c:2156)
> > <4>[ 90.037122] wb_workfn (fs/fs-writeback.c:2303 (discriminator 1)
> > fs/fs-writeback.c:2343 (discriminator 1))
> > <4>[ 90.037318] process_one_work (kernel/workqueue.c:3244)
> > <4>[ 90.037517] worker_thread (kernel/workqueue.c:3316 (discriminator
> > 2) kernel/workqueue.c:3403 (discriminator 2))
> > <4>[ 90.037752] kthread (kernel/kthread.c:463)
> > <4>[ 90.037903] ret_from_fork (arch/arm64/kernel/entry.S:863)
> > <4>[   90.038217] ---[ end trace 0000000000000000 ]---
> > <2>[   90.039950] EXT4-fs (loop0): ext4_do_writepages: jbd2_start:
> > 9223372036854775807 pages, ino 14; err -28
> > <3>[   90.040291] JBD2: kworker/u8:2 wants too many credits
> > credits:416 rsv_credits:21 max:334
> > <4>[   90.040374] ------------[ cut here ]------------
> > <4>[ 90.040386] WARNING: fs/jbd2/transaction.c:334 at
> > start_this_handle+0x4c0/0x4e0, CPU#1: 2/42
> >
> >
> > ## Source
> > * Kernel version: 6.16.0-rc3-next-20250626
> > * Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git
> > * Git sha: ecb259c4f70dd5c83907809f45bf4dc6869961d7
> > * Git describe: 6.16.0-rc3-next-20250626
> > * Project details:
> > https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20250626/
> > * Architectures: arm64
> > * Toolchains: gcc-13
> > * Kconfigs: gcc-13-lkftconfig-64k_page_size
> >
> > ## Build arm64
> > * Test log: https://qa-reports.linaro.org/api/testruns/28894530/log_file/
> > * Test LAVA log 1:
> > https://lkft.validation.linaro.org/scheduler/job/8331353#L6841
> > * Test LAVA log 2:
> > https://lkft.validation.linaro.org/scheduler/job/8331352#L8854
> > * Test details:
> > https://regressions.linaro.org/lkft/linux-next-master/next-20250626/log-parser-test/exception-warning-fsjbd2transaction-at-start_this_handle/
> > * Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/2z2V7LhiJecGzINkU7ObVQTwoR1/
> > * Kernel config:
> > https://storage.tuxsuite.com/public/linaro/lkft/builds/2z2V7LhiJecGzINkU7ObVQTwoR1/config
> >
> > --
> > Linaro LKFT
> > https://lkft.linaro.org
> >
>