2024-02-03 17:57:45

by Theodore Ts'o

[permalink] [raw]
Subject: Re: [PATCH v3 03/26] ext4: correct the hole length returned by ext4_map_blocks()

On Sat, Jan 27, 2024 at 09:58:02AM +0800, Zhang Yi wrote:
> From: Zhang Yi <[email protected]>
>
> In ext4_map_blocks(), if we can't find a range of mapping in the
> extents cache, we are calling ext4_ext_map_blocks() to search the real
> path and ext4_ext_determine_hole() to determine the hole range. But if
> the querying range was partially or completely overlaped by a delalloc
> extent, we can't find it in the real extent path, so the returned hole
> length could be incorrect.
>
> Fortunately, ext4_ext_put_gap_in_cache() have already handle delalloc
> extent, but it searches start from the expanded hole_start, doesn't
> start from the querying range, so the delalloc extent found could not be
> the one that overlaped the querying range, plus, it also didn't adjust
> the hole length. Let's just remove ext4_ext_put_gap_in_cache(), handle
> delalloc and insert adjusted hole extent in ext4_ext_determine_hole().
>
> Signed-off-by: Zhang Yi <[email protected]>
> Suggested-by: Jan Kara <[email protected]>
> Reviewed-by: Jan Kara <[email protected]>

Thanks, applied.

- Ted