On Mon, Sep 09, 2019 at 08:27:08PM +0200, Christoph Hellwig wrote:
> That keeps the function a little easier to understand, and easier to
> modify for pending enhancements.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/iomap/buffered-io.c | 33 ++++++++++++++++-----------------
> 1 file changed, 16 insertions(+), 17 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 0b05551d9b5a..fe099faf540f 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -547,19 +547,12 @@ iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
> }
>
> static int
> -iomap_read_page_sync(struct inode *inode, loff_t block_start, struct page *page,
> - unsigned poff, unsigned plen, unsigned from, unsigned to,
> - struct iomap *iomap)
> +iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff,
> + unsigned plen, struct iomap *iomap)
> {
> struct bio_vec bvec;
> struct bio bio;
>
> - if (iomap_block_needs_zeroing(inode, iomap, block_start)) {
> - zero_user_segments(page, poff, from, to, poff + plen);
> - iomap_set_range_uptodate(page, poff, plen);
> - return 0;
> - }
> -
> bio_init(&bio, &bvec, 1);
> bio.bi_opf = REQ_OP_READ;
> bio.bi_iter.bi_sector = iomap_sector(iomap, block_start);
> @@ -577,7 +570,7 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
> loff_t block_start = pos & ~(block_size - 1);
> loff_t block_end = (pos + len + block_size - 1) & ~(block_size - 1);
> unsigned from = offset_in_page(pos), to = from + len, poff, plen;
> - int status = 0;
> + int status;
>
> if (PageUptodate(page))
> return 0;
> @@ -588,17 +581,23 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
> if (plen == 0)
> break;
>
> - if ((from > poff && from < poff + plen) ||
> - (to > poff && to < poff + plen)) {
> - status = iomap_read_page_sync(inode, block_start, page,
> - poff, plen, from, to, iomap);
> - if (status)
> - break;
> + if ((from <= poff || from >= poff + plen) &&
> + (to <= poff || to >= poff + plen))
> + continue;
> +
> + if (iomap_block_needs_zeroing(inode, iomap, block_start)) {
> + zero_user_segments(page, poff, from, to, poff + plen);
> + iomap_set_range_uptodate(page, poff, plen);
> + continue;
> }
>
> + status = iomap_read_page_sync(block_start, page, poff, plen,
> + iomap);
> + if (status)
> + return status;
> } while ((block_start += plen) < block_end);
>
> - return status;
> + return 0;
> }
>
> static int
> --
> 2.20.1
>
