Re: [bug] scrub on low disk space leads to Transaction aborted

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 2021/1/9 下午4:53, Anand Jain wrote:
>
>   I ran scrub when disk space was low on a btrfs with some raid1 csum
>   errors, on a system with kernel 5.11.0-rc2+. It lead to transaction
>   aborted and rdonly FS.
>

Would you please provide `btrfs fi usage` output?

There is a bug in recent kernel that global rsv is not increased
properly so that we have a much higher chance to exhaust metadata space.

Thanks,
Qu

> [ 2365.314375] ------------[ cut here ]------------
> [ 2365.314385] BTRFS: Transaction aborted (error -28)
> [ 2365.314470] WARNING: CPU: 2 PID: 4672 at fs/btrfs/inode.c:2823
> btrfs_finish_ordered_io+0x8e6/0x950 [btrfs]
> <snap>
> [ 2365.314921] CPU: 2 PID: 4672 Comm: kworker/u8:11 Not tainted
> 5.11.0-rc2+ #3
> [ 2365.314933] Hardware name: LENOVO 20FAS6PN00/20FAS6PN00, BIOS
> N1CET47W (1.15 ) 08/08/2016
> [ 2365.314939] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
> [ 2365.315093] RIP: 0010:btrfs_finish_ordered_io+0x8e6/0x950 [btrfs]
> <snap>
> [ 2365.315290] Call Trace:
> [ 2365.315309] BTRFS warning (device sda6):
> btrfs_finish_ordered_io:2823: Aborting unused transaction(No space left).
> [ 2365.315305]  finish_ordered_fn+0x15/0x20 [btrfs]
> [ 2365.315532]  btrfs_work_helper+0xcc/0x2f0 [btrfs]
> [ 2365.315763]  process_one_work+0x1ee/0x390
> [ 2365.315781]  worker_thread+0x50/0x3d0
> [ 2365.315797]  kthread+0x114/0x150
> [ 2365.315811]  ? process_one_work+0x390/0x390
> [ 2365.315824]  ? kthread_park+0x90/0x90
> [ 2365.315836]  ret_from_fork+0x22/0x30
> [ 2365.315861] ---[ end trace b0e289a2c3d424e8 ]---
> [ 2365.315871] BTRFS warning (device sda6):
> btrfs_finish_ordered_io:2823: Aborting unused transaction(No space left).
> [ 2365.316713] BTRFS warning (device sda6):
> btrfs_finish_ordered_io:2823: Aborting unused transaction(No space left).
> [ 2365.316796] BTRFS warning (device sda6): Skipping commit of aborted
> transaction.
> [ 2365.316809] BTRFS: error (device sda6) in cleanup_transaction:1938:
> errno=-30 Readonly filesystem
> [ 2365.316824] BTRFS info (device sda6): forced readonly
> [ 2365.359195] BTRFS info (device sda6): scrub: not finished on devid 2
> with status: -125