linux-kernel - Re: [syzbot] [bcachefs?] WARNING in bch2_recovery_pass_want

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Message-ID: <68f431e4.a70a0220.205af.000e.GAE@google.com>
Date: Sat, 18 Oct 2025 17:33:40 -0700
From: syzbot <syzbot+3bf8b0169d7fcc0ebcd5@...kaller.appspotmail.com>
To: kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [bcachefs?] WARNING in bch2_recovery_pass_want_ratelimit

syzbot has found a reproducer for the following issue on:

HEAD commit:    bf45a62baffc Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=172ae492580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=bd2356106f507975
dashboard link: https://syzkaller.appspot.com/bug?extid=3bf8b0169d7fcc0ebcd5
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=124fda14580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14fb3de2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f0d4874557e9/disk-bf45a62b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0bf44a13b5b2/vmlinux-bf45a62b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/18db8bc9907c/Image-bf45a62b.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/0638961e34c6/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3bf8b0169d7fcc0ebcd5@...kaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 6755 at fs/bcachefs/recovery_passes.c:174 bch2_recovery_pass_want_ratelimit+0x1c0/0x270 fs/bcachefs/recovery_passes.c:174
Modules linked in:
CPU: 1 UID: 0 PID: 6755 Comm: bch-copygc/loop Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : bch2_recovery_pass_want_ratelimit+0x1c0/0x270 fs/bcachefs/recovery_passes.c:174
lr : bch2_recovery_pass_want_ratelimit+0x1c0/0x270 fs/bcachefs/recovery_passes.c:174
sp : ffff8000a1a76af0
x29: ffff8000a1a76af0 x28: ffff0000f69b8028 x27: ffff0000d4bfe198
x26: 1ffff0001434ed70 x25: dfff800000000000 x24: 0000000000000001
x23: ffff8000a1a76c00 x22: dfff800000000000 x21: 0000000000000000
x20: ffff0000ecf80000 x19: 000000000000000e x18: 00000000ffffffff
x17: ffff80008280dad8 x16: ffff80008052b264 x15: 0000000000000001
x14: 1fffe00018c07b0b x13: 0000000000000000 x12: 0000000000000000
x11: 1ffff0001434ed95 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : ffff0000c8658000 x7 : 2020202020202020 x6 : 696d206874697720
x5 : ffff0000c603d85d x4 : ffff0000c603d85b x3 : 0000000000000002
x2 : ffff8000a1a76b84 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 bch2_recovery_pass_want_ratelimit+0x1c0/0x270 fs/bcachefs/recovery_passes.c:174 (P)
 recovery_pass_needs_set+0xa0/0x468 fs/bcachefs/recovery_passes.c:302
 bch2_run_explicit_recovery_pass+0x4c/0xec fs/bcachefs/recovery_passes.c:416
 bch2_check_bucket_backpointer_mismatch+0x34c/0x3a0 fs/bcachefs/backpointers.c:1220
 __bch2_move_data_phys+0x684/0x144c fs/bcachefs/move.c:1011
 bch2_evacuate_bucket+0x220/0x34c fs/bcachefs/move.c:1082
 bch2_copygc+0x2d80/0x3570 fs/bcachefs/movinggc.c:234
 bch2_copygc_thread+0x898/0xd8c fs/bcachefs/movinggc.c:409
 kthread+0x5fc/0x75c kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844
irq event stamp: 236
hardirqs last  enabled at (235): [<ffff800080c664d0>] kasan_quarantine_put+0x1a0/0x1c8 mm/kasan/quarantine.c:234
hardirqs last disabled at (236): [<ffff80008b05ee64>] el1_brk64+0x20/0x54 arch/arm64/kernel/entry-common.c:434
softirqs last  enabled at (0): [<ffff8000803ba294>] copy_process+0x1134/0x31ec kernel/fork.c:2119
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace 0000000000000000 ]---
bc


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.