On Fri, Aug 02, 2019 at 05:00:37PM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
>
> In case of a IOMAP_COW, read a page from the srcmap before
> performing a write on the page.
Looks ok, I think...
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
>
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
> ---
> fs/iomap/buffered-io.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index f27756c0b31c..a96cc26eec92 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -581,7 +581,7 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
>
> static int
> iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
> - struct page **pagep, struct iomap *iomap)
> + struct page **pagep, struct iomap *iomap, struct iomap *srcmap)
> {
> const struct iomap_page_ops *page_ops = iomap->page_ops;
> pgoff_t index = pos >> PAGE_SHIFT;
> @@ -607,6 +607,8 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
>
> if (iomap->type == IOMAP_INLINE)
> iomap_read_inline_data(inode, page, iomap);
> + else if (iomap->type == IOMAP_COW)
> + status = __iomap_write_begin(inode, pos, len, page, srcmap);
> else if (iomap->flags & IOMAP_F_BUFFER_HEAD)
> status = __block_write_begin_int(page, pos, len, NULL, iomap);
> else
> @@ -772,7 +774,7 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> }
>
> status = iomap_write_begin(inode, pos, bytes, flags, &page,
> - iomap);
> + iomap, srcmap);
> if (unlikely(status))
> break;
>
> @@ -871,7 +873,7 @@ iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> return PTR_ERR(rpage);
>
> status = iomap_write_begin(inode, pos, bytes,
> - AOP_FLAG_NOFS, &page, iomap);
> + AOP_FLAG_NOFS, &page, iomap, srcmap);
> put_page(rpage);
> if (unlikely(status))
> return status;
> @@ -917,13 +919,13 @@ iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
> EXPORT_SYMBOL_GPL(iomap_file_dirty);
>
> static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
> - unsigned bytes, struct iomap *iomap)
> + unsigned bytes, struct iomap *iomap, struct iomap *srcmap)
> {
> struct page *page;
> int status;
>
> status = iomap_write_begin(inode, pos, bytes, AOP_FLAG_NOFS, &page,
> - iomap);
> + iomap, srcmap);
> if (status)
> return status;
>
> @@ -961,7 +963,7 @@ iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
> if (IS_DAX(inode))
> status = iomap_dax_zero(pos, offset, bytes, iomap);
> else
> - status = iomap_zero(inode, pos, offset, bytes, iomap);
> + status = iomap_zero(inode, pos, offset, bytes, iomap, srcmap);
> if (status < 0)
> return status;
>
> --
> 2.16.4
>
