On Wed, Feb 19, 2025 at 12:50:46PM -0500, Brian Foster wrote:
> Advance the iter on successful dedupe. Dedupe range uses two iters
> and iterates so long as both have outstanding work, so
> correspondingly this needs to advance both on each iteration. Since
> dax_range_compare_iter() now returns status instead of a byte count,
> update the variable name in the caller as well.
>
> Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
Double iterators, hrhghghggh
Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
--D
> ---
> fs/dax.c | 21 ++++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/fs/dax.c b/fs/dax.c
> index c0fbab8c66f7..c8c0d81122ab 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -2001,12 +2001,13 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf, unsigned int order,
> }
> EXPORT_SYMBOL_GPL(dax_finish_sync_fault);
>
> -static loff_t dax_range_compare_iter(struct iomap_iter *it_src,
> +static int dax_range_compare_iter(struct iomap_iter *it_src,
> struct iomap_iter *it_dest, u64 len, bool *same)
> {
> const struct iomap *smap = &it_src->iomap;
> const struct iomap *dmap = &it_dest->iomap;
> loff_t pos1 = it_src->pos, pos2 = it_dest->pos;
> + u64 dest_len;
> void *saddr, *daddr;
> int id, ret;
>
> @@ -2014,7 +2015,7 @@ static loff_t dax_range_compare_iter(struct iomap_iter *it_src,
>
> if (smap->type == IOMAP_HOLE && dmap->type == IOMAP_HOLE) {
> *same = true;
> - return len;
> + goto advance;
> }
>
> if (smap->type == IOMAP_HOLE || dmap->type == IOMAP_HOLE) {
> @@ -2037,7 +2038,13 @@ static loff_t dax_range_compare_iter(struct iomap_iter *it_src,
> if (!*same)
> len = 0;
> dax_read_unlock(id);
> - return len;
> +
> +advance:
> + dest_len = len;
> + ret = iomap_iter_advance(it_src, &len);
> + if (!ret)
> + ret = iomap_iter_advance(it_dest, &dest_len);
> + return ret;
>
> out_unlock:
> dax_read_unlock(id);
> @@ -2060,15 +2067,15 @@ int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
> .len = len,
> .flags = IOMAP_DAX,
> };
> - int ret, compared = 0;
> + int ret, status;
>
> while ((ret = iomap_iter(&src_iter, ops)) > 0 &&
> (ret = iomap_iter(&dst_iter, ops)) > 0) {
> - compared = dax_range_compare_iter(&src_iter, &dst_iter,
> + status = dax_range_compare_iter(&src_iter, &dst_iter,
> min(src_iter.len, dst_iter.len), same);
> - if (compared < 0)
> + if (status < 0)
> return ret;
> - src_iter.processed = dst_iter.processed = compared;
> + src_iter.processed = dst_iter.processed = status;
> }
> return ret;
> }
> --
> 2.48.1
>
>
