On Thu, Apr 08, 2021 at 08:04:29PM +0800, Shiyang Ruan wrote:
> Some operations, such as comparing a range of data in two files under
> fsdax mode, requires nested iomap_open()/iomap_end() on two file. Thus,
> we introduce iomap_apply2() to accept arguments from two files and
> iomap_actor2_t for actions on two files.
>
> Signed-off-by: Shiyang Ruan
Kinda wish we weren't propagating even more indirect call usage, but oh
well.
Reviewed-by: Darrick J. Wong
--D
> ---
> fs/iomap/apply.c | 52 +++
> include/linux/iomap.h | 7 +-
> 2 files changed, 58 insertions(+), 1 deletion(-)
>
> diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c
> index 26ab6563181f..0493da5286ad 100644
> --- a/fs/iomap/apply.c
> +++ b/fs/iomap/apply.c
> @@ -97,3 +97,55 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t
> length, unsigned flags,
>
> return written ? written : ret;
> }
> +
> +loff_t
> +iomap_apply2(struct inode *ino1, loff_t pos1, struct inode *ino2, loff_t
> pos2,
> + loff_t length, unsigned int flags, const struct iomap_ops *ops,
> + void *data, iomap_actor2_t actor)
> +{
> + struct iomap smap = { .type = IOMAP_HOLE };
> + struct iomap dmap = { .type = IOMAP_HOLE };
> + loff_t written = 0, ret, ret2 = 0;
> + loff_t len1 = length, len2, min_len;
> +
> + ret = ops->iomap_begin(ino1, pos1, len1, flags, &smap, NULL);
> + if (ret)
> + goto out;
> + if (WARN_ON(smap.offset > pos1)) {
> + written = -EIO;
> + goto out_src;
> + }
> + if (WARN_ON(smap.length == 0)) {
> + written = -EIO;
> + goto out_src;
> + }
> + len2 = min_t(loff_t, len1, smap.length);
> +
> + ret = ops->iomap_begin(ino2, pos2, len2, flags, &dmap, NULL);
> + if (ret)
> + goto out_src;
> + if (WARN_ON(dmap.offset > pos2)) {
> + written = -EIO;
> + goto out_dest;
> + }
> + if (WARN_ON(dmap.length == 0)) {
> + written = -EIO;
> + goto out_dest;
> + }
> + min_len = min_t(loff_t, len2, dmap.length);
> +
> + written = actor(ino1, pos1, ino2, pos2, min_len, data, &smap, &dmap);
> +
> +out_dest:
> + if (ops->iomap_end)
> + ret2 = ops->iomap_end(ino2, pos2, len2,
> + written > 0 ? written : 0, flags, &dmap);
> +out_src:
> + if (ops->iomap_end)
> + ret = ops->iomap_end(ino1, pos1, len1,
> + written > 0 ? written : 0, flags, &smap);
> +out:
> + if (written)
> + return written;
> + return ret ?: ret2;
> +}
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index d202fd2d0f91..9493c48bcc9c 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -150,10 +150,15 @@ struct iomap_ops {
> */
> typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len,
> void *data, struct iomap *iomap, struct iomap *srcmap);
> -
> +typedef loff_t (*iomap_actor2_t)(struct inode *ino1, loff_t pos1,
> + struct inode *ino2, loff_t pos2, loff_t len, void *data,
> + struct iomap *smap, struct iomap *dmap);
> loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length,
> unsigned flags, const struct iomap_ops *ops, void *data,
> iomap_actor_t actor);
> +loff_t iomap_apply2(struct inode *ino1, loff_t pos1, struct inode *ino2,
> + loff_t pos2, loff_t length, unsigned int flags,
> + const struct iomap_ops *ops, void *data, iomap_actor2_t actor);
>
> ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
> const struct iomap_ops *ops);
> --
> 2.31.0
>
>
>
