On Wed, Feb 19, 2025 at 12:50:44PM -0500, Brian Foster wrote:
> Update the DAX zero range iomap iter handler to advance the iter
> directly. Advance by the full length in the hole/unwritten case, or
> otherwise advance incrementally in the zeroing loop. In either case,
> return 0 or an error code for success or failure.
>
> Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
Pretty straightforward
Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
--D
> ---
> fs/dax.c | 33 +++++++++++++++++----------------
> 1 file changed, 17 insertions(+), 16 deletions(-)
>
> diff --git a/fs/dax.c b/fs/dax.c
> index 139e299e53e6..f4d8c8c10086 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1358,13 +1358,12 @@ static s64 dax_zero_iter(struct iomap_iter *iter, bool *did_zero)
> {
> const struct iomap *iomap = &iter->iomap;
> const struct iomap *srcmap = iomap_iter_srcmap(iter);
> - loff_t pos = iter->pos;
> u64 length = iomap_length(iter);
> - s64 written = 0;
> + s64 ret;
>
> /* already zeroed? we're done. */
> if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN)
> - return length;
> + return iomap_iter_advance(iter, &length);
>
> /*
> * invalidate the pages whose sharing state is to be changed
> @@ -1372,33 +1371,35 @@ static s64 dax_zero_iter(struct iomap_iter *iter, bool *did_zero)
> */
> if (iomap->flags & IOMAP_F_SHARED)
> invalidate_inode_pages2_range(iter->inode->i_mapping,
> - pos >> PAGE_SHIFT,
> - (pos + length - 1) >> PAGE_SHIFT);
> + iter->pos >> PAGE_SHIFT,
> + (iter->pos + length - 1) >> PAGE_SHIFT);
>
> do {
> + loff_t pos = iter->pos;
> unsigned offset = offset_in_page(pos);
> - unsigned size = min_t(u64, PAGE_SIZE - offset, length);
> pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);
> - long rc;
> int id;
>
> + length = min_t(u64, PAGE_SIZE - offset, length);
> +
> id = dax_read_lock();
> - if (IS_ALIGNED(pos, PAGE_SIZE) && size == PAGE_SIZE)
> - rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
> + if (IS_ALIGNED(pos, PAGE_SIZE) && length == PAGE_SIZE)
> + ret = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
> else
> - rc = dax_memzero(iter, pos, size);
> + ret = dax_memzero(iter, pos, length);
> dax_read_unlock(id);
>
> - if (rc < 0)
> - return rc;
> - pos += size;
> - length -= size;
> - written += size;
> + if (ret < 0)
> + return ret;
> +
> + ret = iomap_iter_advance(iter, &length);
> + if (ret)
> + return ret;
> } while (length > 0);
>
> if (did_zero)
> *did_zero = true;
> - return written;
> + return ret;
> }
>
> int dax_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
> --
> 2.48.1
>
>
