Re: [PATCH 01/13] btrfs: fix missed extent on fsync after dropping extent maps

[Anand Jain <anand.jain@oracle.com>]

On 19/09/2022 22:06, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> When dropping extent maps for a range, through btrfs_drop_extent_cache(),
> if we find an extent map that starts before our target range and/or ends
> before the target range, and we are not able to allocate extent maps for
> splitting that extent map, then we don't fail and simply remove the entire
> extent map from the inode's extent map tree.


> +		if (testend && em->start + em->len > start + len)

  %len comes from

  	u64 len = end - start + 1;

  IMO >= was correct here; because including %start + %len is already
  after the range as in the original code. No?

> +			ends_after_range = true;
>   		flags = em->flags;
>   		gen = em->generation;
>   		if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
> -			if (testend && em->start + em->len >= start + len) {
> +			if (ends_after_range) {
>   				free_extent_map(em);
>   				write_unlock(&em_tree->lock);
>   				break;