On Tue 07-05-24 14:25:42, Ritesh Harjani (IBM) wrote:
> If the extent spans the block that contains i_size, we need to handle
> both halves separately so that we properly zero data in the page cache
> for blocks that are entirely outside of i_size. But this is needed only
> when i_size is within the current folio under processing.
> "orig_pos + length > isize" can be true for all folios if the mapped
> extent length is greater than the folio size. That is making plen to
> break for every folio instead of only the last folio.
>
> So use orig_plen for checking if "orig_pos + orig_plen > isize".
>
> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
> cc: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/iomap/buffered-io.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 4e8e41c8b3c0..9f79c82d1f73 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -241,6 +241,7 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio,
> unsigned block_size = (1 << block_bits);
> size_t poff = offset_in_folio(folio, *pos);
> size_t plen = min_t(loff_t, folio_size(folio) - poff, length);
> + size_t orig_plen = plen;
> unsigned first = poff >> block_bits;
> unsigned last = (poff + plen - 1) >> block_bits;
>
> @@ -277,7 +278,7 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio,
> * handle both halves separately so that we properly zero data in the
> * page cache for blocks that are entirely outside of i_size.
> */
> - if (orig_pos <= isize && orig_pos + length > isize) {
> + if (orig_pos <= isize && orig_pos + orig_plen > isize) {
> unsigned end = offset_in_folio(folio, isize - 1) >> block_bits;
>
> if (first <= end && last > end)
> --
> 2.44.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
