WARNING in __bch2_truncate_folio

Hello,

syzbot found the following issue on:

HEAD commit:    b6394d6f7159 Merge tag 'pull-misc' of git://git.kernel.org..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=14953df4980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=713476114e57eef3
dashboard link: https://syzkaller.appspot.com/bug?extid=3d11e35eeafe176a6c5b
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15c2ef84980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=115a1592980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e8e1377d4772/disk-b6394d6f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/19fbbb3b6dd5/vmlinux-b6394d6f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4dcce16af95d/bzImage-b6394d6f.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/cff7ebd31dbf/mount_0.gz

The issue was bisected to:

commit f7643bc9749f270d487c32dc35b578575bf1adb0

Author: Kent Overstreet <[email protected]>
Date:   Wed Apr 17 05:26:02 2024 +0000

bcachefs: make btree read errors silent during scan

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=11f1b784980000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=13f1b784980000
console output: https://syzkaller.appspot.com/x/log.txt?x=15f1b784980000

IMPORTANT: if you fix the issue, please add the following tag to the commit:

bcachefs (loop0): resume_logged_ops... done
bcachefs (loop0): going read-write
bcachefs (loop0): done starting filesystem

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5083 at fs/bcachefs/fs-io.c:327 __bch2_truncate_folio+0x1a33/0x1d80 fs/bcachefs/fs-io.c:327
Modules linked in:
CPU: 0 PID: 5083 Comm: syz-executor322 Not tainted 6.9.0-syzkaller-10729-gb6394d6f7159 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:__bch2_truncate_folio+0x1a33/0x1d80 fs/bcachefs/fs-io.c:327
Code: 41 5f 5d c3 cc cc cc cc e8 3a 00 6f fd 48 c7 c7 fa 04 c0 8d e8 4e 1c ea ff 89 05 18 02 6a 10 e9 ed ea ff ff e8 1e 00 6f fd 90 <0f> 0b 90 e9 0a fa ff ff 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c f0
RSP: 0018:ffffc900033df6c0 EFLAGS: 00010293
RAX: ffffffff84273a52 RBX: 0000000000000000 RCX: ffff888078fb8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900033df950 R08: ffffffff84273457 R09: 1ffffd400014f498
R10: dffffc0000000000 R11: fffff9400014f499 R12: 1ffff1100ecd900a
R13: ffff88807420075a R14: 0000000000000000 R15: ffff8880766c8050
FS:  000055555b7d5380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f47f45440f8 CR3: 0000000077134000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_truncate_folios fs/bcachefs/fs-io.c:366 [inline]
 bchfs_fpunch fs/bcachefs/fs-io.c:520 [inline]
 bch2_fallocate_dispatch+0x6fb/0x3810 fs/bcachefs/fs-io.c:785
 vfs_fallocate+0x564/0x6c0 fs/open.c:330
 ksys_fallocate fs/open.c:353 [inline]
 __do_sys_fallocate fs/open.c:361 [inline]
 __se_sys_fallocate fs/open.c:359 [inline]
 __x64_sys_fallocate+0xbd/0x110 fs/open.c:359
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f47f44c7a99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffec1ed9828 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f47f44c7a99
RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007f47f45405f0 R08: 000055555b7d64c0 R09: 000055555b7d64c0
R10: 0000000000010000 R11: 0000000000000246 R12: 00007ffec1ed9850
R13: 00007ffec1ed9a78 R14: 431bde82d7b634db R15: 00007f47f451003b
 </TASK>

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