diff mbox series

[v3,07/10] iomap: Introduce iomap_apply2() for operations on two files

Message ID 20210319015237.993880-8-ruansy.fnst@fujitsu.com (mailing list archive)
State Superseded
Headers show
Series fsdax,xfs: Add reflink&dedupe support for fsdax | expand

Commit Message

ruansy.fnst@fujitsu.com March 19, 2021, 1:52 a.m. UTC
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 <ruansy.fnst@fujitsu.com>
---
 fs/iomap/apply.c      | 56 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/iomap.h |  7 +++++-
 2 files changed, 62 insertions(+), 1 deletion(-)

Comments

Ritesh Harjani April 1, 2021, 7:12 a.m. UTC | #1
On 21/03/19 09:52AM, 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 <ruansy.fnst@fujitsu.com>
> ---
>  fs/iomap/apply.c      | 56 +++++++++++++++++++++++++++++++++++++++++++
>  include/linux/iomap.h |  7 +++++-
>  2 files changed, 62 insertions(+), 1 deletion(-)
>
> diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c
> index 26ab6563181f..fbc38ce3d5b6 100644
> --- a/fs/iomap/apply.c
> +++ b/fs/iomap/apply.c
> @@ -97,3 +97,59 @@ 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_src;

if above call fails we need not call ->iomap_end() on smap.

> +	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_dest;

ditto

> +	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);
> +

I guess, this maynot be a problem, but I still think we should be
consistent w.r.t len argument we are passing in ->iomap_end() for both type of
iomap_apply* family of functions.
IIUC, we used to call ->iomap_end() with the length argument filled by the
filesystem from ->iomap_begin() call.

whereas above breaks that behavior. Although I don't think this is FATAL, but
still it is better to be consistent with the APIs.
Thoughts?


> +	if (ret)
> +		return written ? written : ret;
> +
> +	if (ret2)
> +		return written ? written : ret2;
> +
> +	return written;
> +}

	if (written)
		return written;

	return ret ? ret : ret2;

Is above a simpler version?

-ritesh
diff mbox series

Patch

diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c
index 26ab6563181f..fbc38ce3d5b6 100644
--- a/fs/iomap/apply.c
+++ b/fs/iomap/apply.c
@@ -97,3 +97,59 @@  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_src;
+	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_dest;
+	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);
+
+	if (ret)
+		return written ? written : ret;
+
+	if (ret2)
+		return written ? written : ret2;
+
+	return written;
+}
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 5bd3cac4df9c..913f98897a77 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -148,10 +148,15 @@  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);