diff mbox series

[v21,03/30] splice: Rename direct_splice_read() to copy_splice_read()

Message ID 20230520000049.2226926-4-dhowells@redhat.com (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

David Howells May 20, 2023, midnight UTC
Rename direct_splice_read() to copy_splice_read() to better reflect as to
what it does.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Steve French <sfrench@samba.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
---
 fs/cifs/cifsfs.c   |  4 ++--
 fs/cifs/file.c     |  2 +-
 fs/splice.c        | 11 +++++------
 include/linux/fs.h |  6 +++---
 4 files changed, 11 insertions(+), 12 deletions(-)

Comments

Christoph Hellwig May 20, 2023, 4:09 a.m. UTC | #1
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Christian Brauner May 20, 2023, 9:23 a.m. UTC | #2
On Sat, May 20, 2023 at 01:00:22AM +0100, David Howells wrote:
> Rename direct_splice_read() to copy_splice_read() to better reflect as to
> what it does.
> 
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Christoph Hellwig <hch@lst.de>
> cc: Steve French <sfrench@samba.org>
> cc: Jens Axboe <axboe@kernel.dk>
> cc: Al Viro <viro@zeniv.linux.org.uk>
> cc: linux-cifs@vger.kernel.org
> cc: linux-mm@kvack.org
> cc: linux-block@vger.kernel.org
> cc: linux-fsdevel@vger.kernel.org
> ---

For the future it'd be nice if exported functions would always get
proper kernel doc,
Reviewed-by: Christian Brauner <brauner@kernel.org>
David Howells May 20, 2023, 9:51 a.m. UTC | #3
Christian Brauner <brauner@kernel.org> wrote:

> For the future it'd be nice if exported functions would always get
> proper kernel doc,

Good point.  It wasn't meant to remain exported originally.  I'll add a patch
to add that.

David
David Howells May 22, 2023, 7:55 a.m. UTC | #4
> For the future it'd be nice if exported functions would always get
> proper kernel doc,

Something like the attached?

David
---
commit 0362042ba0751fc5457b0548fb9006f9d7dfbeca
Author: David Howells <dhowells@redhat.com>
Date:   Mon May 22 08:34:24 2023 +0100

    splice: kdoc for filemap_splice_read() and copy_splice_read()
    
    Provide kerneldoc comments for filemap_splice_read() and
    copy_splice_read().
    
    Signed-off-by: David Howells <dhowells@redhat.com>
    cc: Christian Brauner <brauner@kernel.org>
    cc: Christoph Hellwig <hch@lst.de>
    cc: Jens Axboe <axboe@kernel.dk>
    cc: Steve French <smfrench@gmail.com>
    cc: Al Viro <viro@zeniv.linux.org.uk>
    cc: linux-mm@kvack.org
    cc: linux-block@vger.kernel.org
    cc: linux-cifs@vger.kernel.org
    cc: linux-fsdevel@vger.kernel.org

diff --git a/fs/splice.c b/fs/splice.c
index 9be4cb3b9879..5292a8fa929d 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -299,8 +299,25 @@ void splice_shrink_spd(struct splice_pipe_desc *spd)
 	kfree(spd->partial);
 }
 
-/*
- * Copy data from a file into pages and then splice those into the output pipe.
+/**
+ * copy_splice_read -  Copy data from a file and splice the copy into a pipe
+ * @in: The file to read from
+ * @ppos: Pointer to the file position to read from
+ * @pipe: The pipe to splice into
+ * @len: The amount to splice
+ * @flags: The SPLICE_F_* flags
+ *
+ * This function allocates a bunch of pages sufficient to hold the requested
+ * amount of data (but limited by the remaining pipe capacity), passes it to
+ * the file's ->read_iter() to read into and then splices the used pages into
+ * the pipe.
+ *
+ * On success, the number of bytes read will be returned and *@ppos will be
+ * updated if appropriate; 0 will be returned if there is no more data to be
+ * read; -EAGAIN will be returned if the pipe had no space, and some other
+ * negative error code will be returned on error.  A short read may occur if
+ * the pipe has insufficient space, we reach the end of the data or we hit a
+ * hole.
  */
 ssize_t copy_splice_read(struct file *in, loff_t *ppos,
 			 struct pipe_inode_info *pipe,
diff --git a/mm/filemap.c b/mm/filemap.c
index 603b562d69b1..1f235a6430fd 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2871,9 +2871,24 @@ size_t splice_folio_into_pipe(struct pipe_inode_info *pipe,
 	return spliced;
 }
 
-/*
- * Splice folios from the pagecache of a buffered (ie. non-O_DIRECT) file into
- * a pipe.
+/**
+ * filemap_splice_read -  Splice data from a file's pagecache into a pipe
+ * @in: The file to read from
+ * @ppos: Pointer to the file position to read from
+ * @pipe: The pipe to splice into
+ * @len: The amount to splice
+ * @flags: The SPLICE_F_* flags
+ *
+ * This function gets folios from a file's pagecache and splices them into the
+ * pipe.  Readahead will be called as necessary to fill more folios.  This may
+ * be used for blockdevs also.
+ *
+ * On success, the number of bytes read will be returned and *@ppos will be
+ * updated if appropriate; 0 will be returned if there is no more data to be
+ * read; -EAGAIN will be returned if the pipe had no space, and some other
+ * negative error code will be returned on error.  A short read may occur if
+ * the pipe has insufficient space, we reach the end of the data or we hit a
+ * hole.
  */
 ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
 			    struct pipe_inode_info *pipe,
Christian Brauner May 22, 2023, 12:53 p.m. UTC | #5
On Mon, May 22, 2023 at 08:55:14AM +0100, David Howells wrote:
> > For the future it'd be nice if exported functions would always get
> > proper kernel doc,
> 
> Something like the attached?
> 
> David
> ---
> commit 0362042ba0751fc5457b0548fb9006f9d7dfbeca
> Author: David Howells <dhowells@redhat.com>
> Date:   Mon May 22 08:34:24 2023 +0100
> 
>     splice: kdoc for filemap_splice_read() and copy_splice_read()
>     
>     Provide kerneldoc comments for filemap_splice_read() and
>     copy_splice_read().
>     
>     Signed-off-by: David Howells <dhowells@redhat.com>
>     cc: Christian Brauner <brauner@kernel.org>
>     cc: Christoph Hellwig <hch@lst.de>
>     cc: Jens Axboe <axboe@kernel.dk>
>     cc: Steve French <smfrench@gmail.com>
>     cc: Al Viro <viro@zeniv.linux.org.uk>
>     cc: linux-mm@kvack.org
>     cc: linux-block@vger.kernel.org
>     cc: linux-cifs@vger.kernel.org
>     cc: linux-fsdevel@vger.kernel.org
> 
> diff --git a/fs/splice.c b/fs/splice.c
> index 9be4cb3b9879..5292a8fa929d 100644
> --- a/fs/splice.c
> +++ b/fs/splice.c
> @@ -299,8 +299,25 @@ void splice_shrink_spd(struct splice_pipe_desc *spd)
>  	kfree(spd->partial);
>  }
>  
> -/*
> - * Copy data from a file into pages and then splice those into the output pipe.
> +/**
> + * copy_splice_read -  Copy data from a file and splice the copy into a pipe
> + * @in: The file to read from
> + * @ppos: Pointer to the file position to read from
> + * @pipe: The pipe to splice into
> + * @len: The amount to splice
> + * @flags: The SPLICE_F_* flags
> + *
> + * This function allocates a bunch of pages sufficient to hold the requested
> + * amount of data (but limited by the remaining pipe capacity), passes it to
> + * the file's ->read_iter() to read into and then splices the used pages into
> + * the pipe.
> + *
> + * On success, the number of bytes read will be returned and *@ppos will be
> + * updated if appropriate; 0 will be returned if there is no more data to be
> + * read; -EAGAIN will be returned if the pipe had no space, and some other
> + * negative error code will be returned on error.  A short read may occur if
> + * the pipe has insufficient space, we reach the end of the data or we hit a
> + * hole.
>   */

I think kdoc expects:

* Return: On success, the number of bytes read will be returned and *@ppos will be
* updated if appropriate; 0 will be returned if there is no more data to be
* read; -EAGAIN will be returned if the pipe had no space, and some other
* negative error code will be returned on error.  A short read may occur if
* the pipe has insufficient space, we reach the end of the data or we hit a
* hole.

and similar for filemap_splice_read() other than that this looks good!

>  ssize_t copy_splice_read(struct file *in, loff_t *ppos,
>  			 struct pipe_inode_info *pipe,
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 603b562d69b1..1f235a6430fd 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -2871,9 +2871,24 @@ size_t splice_folio_into_pipe(struct pipe_inode_info *pipe,
>  	return spliced;
>  }
>  
> -/*
> - * Splice folios from the pagecache of a buffered (ie. non-O_DIRECT) file into
> - * a pipe.
> +/**
> + * filemap_splice_read -  Splice data from a file's pagecache into a pipe
> + * @in: The file to read from
> + * @ppos: Pointer to the file position to read from
> + * @pipe: The pipe to splice into
> + * @len: The amount to splice
> + * @flags: The SPLICE_F_* flags
> + *
> + * This function gets folios from a file's pagecache and splices them into the
> + * pipe.  Readahead will be called as necessary to fill more folios.  This may
> + * be used for blockdevs also.
> + *
> + * On success, the number of bytes read will be returned and *@ppos will be
> + * updated if appropriate; 0 will be returned if there is no more data to be
> + * read; -EAGAIN will be returned if the pipe had no space, and some other
> + * negative error code will be returned on error.  A short read may occur if
> + * the pipe has insufficient space, we reach the end of the data or we hit a
> + * hole.
>   */
>  ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
>  			    struct pipe_inode_info *pipe,
>
diff mbox series

Patch

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 43a4d8603db3..fa2477bbcc86 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -1416,7 +1416,7 @@  const struct file_operations cifs_file_direct_ops = {
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
 	.mmap = cifs_file_mmap,
-	.splice_read = direct_splice_read,
+	.splice_read = copy_splice_read,
 	.splice_write = iter_file_splice_write,
 	.unlocked_ioctl  = cifs_ioctl,
 	.copy_file_range = cifs_copy_file_range,
@@ -1470,7 +1470,7 @@  const struct file_operations cifs_file_direct_nobrl_ops = {
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
 	.mmap = cifs_file_mmap,
-	.splice_read = direct_splice_read,
+	.splice_read = copy_splice_read,
 	.splice_write = iter_file_splice_write,
 	.unlocked_ioctl  = cifs_ioctl,
 	.copy_file_range = cifs_copy_file_range,
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index c5fcefdfd797..023496207c18 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -5091,6 +5091,6 @@  ssize_t cifs_splice_read(struct file *in, loff_t *ppos,
 	if (unlikely(!len))
 		return 0;
 	if (in->f_flags & O_DIRECT)
-		return direct_splice_read(in, ppos, pipe, len, flags);
+		return copy_splice_read(in, ppos, pipe, len, flags);
 	return filemap_splice_read(in, ppos, pipe, len, flags);
 }
diff --git a/fs/splice.c b/fs/splice.c
index 3e06611d19ae..2478e065bc53 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -300,12 +300,11 @@  void splice_shrink_spd(struct splice_pipe_desc *spd)
 }
 
 /*
- * Splice data from an O_DIRECT file into pages and then add them to the output
- * pipe.
+ * Copy data from a file into pages and then splice those into the output pipe.
  */
-ssize_t direct_splice_read(struct file *in, loff_t *ppos,
-			   struct pipe_inode_info *pipe,
-			   size_t len, unsigned int flags)
+ssize_t copy_splice_read(struct file *in, loff_t *ppos,
+			 struct pipe_inode_info *pipe,
+			 size_t len, unsigned int flags)
 {
 	struct iov_iter to;
 	struct bio_vec *bv;
@@ -390,7 +389,7 @@  ssize_t direct_splice_read(struct file *in, loff_t *ppos,
 	kfree(bv);
 	return ret;
 }
-EXPORT_SYMBOL(direct_splice_read);
+EXPORT_SYMBOL(copy_splice_read);
 
 /**
  * generic_file_splice_read - splice data from file to a pipe
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 21a981680856..e3c22efa413e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2752,9 +2752,9 @@  ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
 ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
 			    struct pipe_inode_info *pipe,
 			    size_t len, unsigned int flags);
-ssize_t direct_splice_read(struct file *in, loff_t *ppos,
-			   struct pipe_inode_info *pipe,
-			   size_t len, unsigned int flags);
+ssize_t copy_splice_read(struct file *in, loff_t *ppos,
+			 struct pipe_inode_info *pipe,
+			 size_t len, unsigned int flags);
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
 		struct pipe_inode_info *, size_t, unsigned int);
 extern ssize_t iter_file_splice_write(struct pipe_inode_info *,