[syzbot] WARNING in find_free_extent_update_loop

syzbot
2022-10-29T13:35:56Z

Hello,

syzbot found the following issue on:

HEAD commit: b229b6ca5abb Merge tag 'perf-tools-fixes-for-v6.1-2022-10-..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12c0475a880000
kernel config: https://syzkaller.appspot.com/x/.config?x=1d3548a4365ba17d
dashboard link: https://syzkaller.appspot.com/bug?extid=1ab183c4029913aa8e4c
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/24728b72a896/disk-b229b6ca.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/10a3c40c60e1/vmlinux-b229b6ca.xz
kernel image: https://storage.googleapis.com/syzbot-assets/69f963b02b7e/bzImage-b229b6ca.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1ab183c4029913aa8e4c@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 31718 at fs/btrfs/extent-tree.c:4118 find_free_extent_update_loop+0xa1a/0xd00 fs/btrfs/extent-tree.c:4118
Modules linked in:
CPU: 0 PID: 31718 Comm: syz-executor.1 Not tainted 6.1.0-rc2-syzkaller-00105-gb229b6ca5abb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
RIP: 0010:find_free_extent_update_loop+0xa1a/0xd00 fs/btrfs/extent-tree.c:4118
Code: 00 48 c7 c6 a0 33 da 8a 44 89 f2 31 c0 e8 b0 a1 ad 06 eb 1a e8 c7 a6 03 fe 48 c7 c7 a0 32 da 8a 44 89 f6 31 c0 e8 16 45 cb fd <0f> 0b b3 01 4c 8b 6c 24 08 44 0f b6 c3 4c 89 ff 48 c7 c6 40 48 da
RSP: 0018:ffffc9000354e950 EFLAGS: 00010246
RAX: 9bc899dcf6ac9a00 RBX: 00000000fffffff4 RCX: 0000000000040000
RDX: ffffc9000d255000 RSI: 000000000000f22a RDI: 000000000000f22b
RBP: ffff888088f3e050 R08: ffffffff816b8dfd R09: ffffed1017344f13
R10: ffffed1017344f13 R11: 1ffff11017344f12 R12: 0000000000000000
R13: 1ffff110111e7c0a R14: 00000000fffffff4 R15: ffff888088f3e000
FS: 00007f875efde700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020701000 CR3: 00000000271de000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
find_free_extent+0x1740/0x4230 fs/btrfs/extent-tree.c:4470
btrfs_reserve_extent+0x421/0x800 fs/btrfs/extent-tree.c:4563
cow_file_range+0x52e/0xfa0 fs/btrfs/inode.c:1276
btrfs_run_delalloc_range+0xed4/0x11a0 fs/btrfs/inode.c:2229
writepage_delalloc+0x25e/0x540 fs/btrfs/extent_io.c:1968
__extent_writepage+0x5d6/0x14d0 fs/btrfs/extent_io.c:2272
extent_write_cache_pages+0x9e7/0x12d0 fs/btrfs/extent_io.c:3186
extent_writepages+0x228/0x550 fs/btrfs/extent_io.c:3308
do_writepages+0x3c3/0x680 mm/page-writeback.c:2469
filemap_fdatawrite_wbc+0x11e/0x170 mm/filemap.c:388
__filemap_fdatawrite_range mm/filemap.c:421 [inline]
filemap_fdatawrite_range+0x175/0x200 mm/filemap.c:439
btrfs_fdatawrite_range fs/btrfs/file.c:4140 [inline]
start_ordered_ops fs/btrfs/file.c:2026 [inline]
btrfs_sync_file+0x39e/0x1140 fs/btrfs/file.c:2102
generic_write_sync include/linux/fs.h:2883 [inline]
btrfs_do_write_iter+0xa6f/0x1370 fs/btrfs/file.c:1975
call_write_iter include/linux/fs.h:2191 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x7dc/0xc50 fs/read_write.c:584
ksys_write+0x177/0x2a0 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f875fc8b5a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007f875efde168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f875fdac050 RCX: 00007f875fc8b5a9
RDX: 0000000000000010 RSI: 0000000020000bc0 RDI: 0000000000000003
RBP: 00007f875efde1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffd6082437f R14: 00007f875efde300 R15: 0000000000022000
</TASK>

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