Re: [PATCH v4 00/14] btrfs: more RST delete fixes

[David Sterba <dsterba@suse.cz>]

On Mon, Jan 13, 2025 at 08:31:41PM +0100, Johannes Thumshirn wrote:
> Here's another set of fixes for the delete path on RAID stripe-tree backed
> filesystems.
> 
> Josef's CI system started tripping over a bad key order due to the usage
> of btrfs_set_item_key_safe() in btrfs_partially_delete_raid_extent() and
> while investigating what is happening there I found more bugs and not
> handled corner cases, which resulted in more fixes and test-cases.
> 
> Unfortunately I couldn't fix the bad key order problem and had to resort
> to re-creating the item in btrfs_partially_delete_raid_extent() and insert
> the new one after deleting the old.
> 
> Fstests btrfs/06* are extremely good in exhibiting these failures and
> btrfs/060 has been extensively run while developing this series.
> 
> A full CI run of v1 can be found here:
> https://github.com/btrfs/linux/actions/runs/12291668397
> 
> Changes to v1:
> - Handle extent_map lookup failure in 1/14
> - Don't use key.offset = -1 for initial search in 3/14
> - Don't break before calling btrfs_previous_item if we're on slot 0 in
>   6/14
> - Remove btrfs_mark_buffer_dirty calls
> - Remove line breaks at 80 chars if we're just a bit over
> - Fix multiple issues on comment styling
> 
> Link to v1:
> https://lore.kernel.org/linux-btrfs/cover.1733989299.git.jth@kernel.org
> 
> Note:
> I did not copy the implementation of btrfs_drop_extents() as I'd like to
> have feedback on this variant first, before putting the time and energy in
> a "completely new" implementation.
> 
> ---
> Changes in v4:
> - Handle case when btrfs_previous_item returns 1
> - Explicitly document that the root cause of the tree corruption is
>   unclear
> - Link to v3: https://lore.kernel.org/r/20250109-rst-delete-fixes-v3-0-b5c73a4b2a80@kernel.org

I've added the series to for-next, with some minor fixups.