[syzbot] [ext4?] WARNING in ext4_da_update_reserve_space (2)

From: syzbot
Date: Sun Mar 26 2023 - 06:45:33 EST


Hello,

syzbot found the following issue on:

HEAD commit: fff5a5e7f528 Merge tag 'for-linus' of git://git.armlinux.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=106ebc66c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=d40f6d44826f6cf7
dashboard link: https://syzkaller.appspot.com/bug?extid=a1232eabd7a3d43d4fb5
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10fd867ac80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15094596c80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8f6445f85469/disk-fff5a5e7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a04a9ef0da2b/vmlinux-fff5a5e7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/414b78e64804/bzImage-fff5a5e7.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/0563d853a594/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a1232eabd7a3d43d4fb5@xxxxxxxxxxxxxxxxxxxxxxxxx

EXT4-fs warning (device loop1): ext4_da_update_reserve_space:372: ext4_da_update_reserve_space: ino 18, used 1 with only 0 reserved data blocks
------------[ cut here ]------------
WARNING: CPU: 1 PID: 41 at fs/ext4/inode.c:373 ext4_da_update_reserve_space+0x419/0x730 fs/ext4/inode.c:369
Modules linked in:
CPU: 1 PID: 41 Comm: kworker/u4:2 Not tainted 6.3.0-rc3-syzkaller-00026-gfff5a5e7f528 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Workqueue: writeback wb_workfn (flush-7:1)
RIP: 0010:ext4_da_update_reserve_space+0x419/0x730 fs/ext4/inode.c:373
Code: 4c 89 ff 48 c7 c6 69 9e 82 8c ba 74 01 00 00 48 c7 c1 c0 3c fc 8a 49 c7 c0 69 9e 82 8c 41 55 41 54 e8 9b bb 0e 00 48 83 c4 10 <0f> 0b 48 bd 00 00 00 00 00 fc ff df 0f b6 04 2b 84 c0 0f 85 8f 01
RSP: 0018:ffffc90000b26cd0 EFLAGS: 00010282
RAX: cf4d35dbf73d9100 RBX: 1ffff1100e9b024d RCX: cf4d35dbf73d9100
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff888074d80cf8 R08: ffffffff816dfe9c R09: fffffbfff205be51
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 0000000000000000 R14: ffff888074d80cb8 R15: ffff88807db7e000
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc7e69ab88 CR3: 00000000764a4000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_map_blocks+0xb64/0x1cf0 fs/ext4/inode.c:672
mpage_map_one_extent fs/ext4/inode.c:2421 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline]
ext4_do_writepages+0x189f/0x3d20 fs/ext4/inode.c:2876
ext4_writepages+0x1e5/0x290 fs/ext4/inode.c:2964
do_writepages+0x3a6/0x670 mm/page-writeback.c:2551
__writeback_single_inode+0x155/0xfb0 fs/fs-writeback.c:1600
writeback_sb_inodes+0x8ef/0x11d0 fs/fs-writeback.c:1891
wb_writeback+0x458/0xc70 fs/fs-writeback.c:2065
wb_do_writeback fs/fs-writeback.c:2208 [inline]
wb_workfn+0x400/0xff0 fs/fs-writeback.c:2248
process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2390
worker_thread+0xa63/0x1210 kernel/workqueue.c:2537
kthread+0x270/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>


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