Re: [PATCH] btrfs: dont loop for nowait writes when checking for cross references

[Josef Bacik <josef@toxicpanda.com>]

On Fri, Nov 15, 2024 at 03:52:38PM +0000, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> When checking for delayed refs when verifying if there are cross
> references for a data extent, we stop if the path has nowait set and we
> can't try lock the delayed ref head's mutex, returning -EAGAIN with the
> goal of making a write fallback to a blocking context. However we ignore
> the -EAGAIN at btrfs_cross_ref_exist() when check_delayed_ref() returns
> it, and keep looping instead of immediately returning the -EGAIN to the
> caller.
> 
> Fix this by not looping if we get -EAGAIN and we have a nowait path.
> 
> Fixes: 26ce91144631 ("btrfs: make can_nocow_extent nowait compatible")
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef