Commit 9eee8bd8 authored by David Howells's avatar David Howells Committed by Jens Axboe
Browse files

splice: kdoc for filemap_splice_read() and copy_splice_read() 



Provide kerneldoc comments for filemap_splice_read() and
copy_splice_read().

Signed-off-by: default avatarDavid 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
Link: https://lore.kernel.org/r/20230522135018.2742245-32-dhowells@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3fc40265

fs/splice.c

+19 −2
Original line number Diff line number Diff line
@@ -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.

 *

 * 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.

 */

ssize_t copy_splice_read(struct file *in, loff_t *ppos,

			 struct pipe_inode_info *pipe,

mm/filemap.c

+18 −3
Original line number Diff line number Diff line
@@ -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.

 *

 * 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.

 */

ssize_t filemap_splice_read(struct file *in, loff_t *ppos,

			    struct pipe_inode_info *pipe,