Re: [PATCH v2 0/5] btrfs: fix relocation on RAID stripe-tree filesystems

[Qu Wenruo]

在 2024/7/30 20:03, Johannes Thumshirn 写道:
> When doing relocation on RST backed filesystems, there is a possibility of
> a scatter-gather list corruption.
>
> See patch 4 for details.
>
> CI Link: https://github.com/btrfs/linux/actions/runs/10143804038
>
> ---
> Changes in v2:
> - Change RST lookup error message to debug
> - Link to v1: https://lore.kernel.org/r/20240729-debug-v1-0-f0b3d78d9438@xxxxxxxxxx
>
> ---
> Johannes Thumshirn (5):
>        btrfs: don't dump stripe-tree on lookup error
>        btrfs: rename btrfs_io_stripe::is_scrub to rst_search_commit_root
>        btrfs: set rst_search_commit_root in case of relocation
>        btrfs: don't readahead the relocation inode on RST
>        btrfs: change RST lookup error message to debug

Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>

The solution looks fine to me, but I have one extra question related to
the readahead.

  Does the readahead fail because it's reading some range not covered by
  any extent?

If so, you may want to add an example to patch 4 to explain the problem
better.

Thanks,
Qu

>   fs/btrfs/bio.c              |  3 ++-
>   fs/btrfs/raid-stripe-tree.c |  8 +++-----
>   fs/btrfs/relocation.c       | 14 ++++++++++----
>   fs/btrfs/scrub.c            |  2 +-
>   fs/btrfs/volumes.h          |  2 +-
>   5 files changed, 17 insertions(+), 12 deletions(-)
> ---
> base-commit: 543cb1b052748dc53ff06b23273fcb78f11b8254
> change-id: 20240726-debug-f1fe805ea37b
>
> Best regards,