Rename direct_splice_read() to copy_splice_read() to better reflect as to
what it does.
Suggested-by: Christoph Hellwig <[email protected]>
Signed-off-by: David Howells <[email protected]>
cc: Christoph Hellwig <[email protected]>
cc: Steve French <[email protected]>
cc: Jens Axboe <[email protected]>
cc: Al Viro <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
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(-)
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 *,
Looks good:
Reviewed-by: Christoph Hellwig <[email protected]>
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 <[email protected]>
> Signed-off-by: David Howells <[email protected]>
> cc: Christoph Hellwig <[email protected]>
> cc: Steve French <[email protected]>
> cc: Jens Axboe <[email protected]>
> cc: Al Viro <[email protected]>
> cc: [email protected]
> cc: [email protected]
> cc: [email protected]
> cc: [email protected]
> ---
For the future it'd be nice if exported functions would always get
proper kernel doc,
Reviewed-by: Christian Brauner <[email protected]>
Christian Brauner <[email protected]> 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
> 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 <[email protected]>
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 <[email protected]>
cc: Christian Brauner <[email protected]>
cc: Christoph Hellwig <[email protected]>
cc: Jens Axboe <[email protected]>
cc: Steve French <[email protected]>
cc: Al Viro <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
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,
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 <[email protected]>
> 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 <[email protected]>
> cc: Christian Brauner <[email protected]>
> cc: Christoph Hellwig <[email protected]>
> cc: Jens Axboe <[email protected]>
> cc: Steve French <[email protected]>
> cc: Al Viro <[email protected]>
> cc: [email protected]
> cc: [email protected]
> cc: [email protected]
> cc: [email protected]
>
> 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,
>