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@xxxxxxxxxx> > 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@xxxxxxxxxx> > cc: Christian Brauner <brauner@xxxxxxxxxx> > cc: Christoph Hellwig <hch@xxxxxx> > cc: Jens Axboe <axboe@xxxxxxxxx> > cc: Steve French <smfrench@xxxxxxxxx> > cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > cc: linux-mm@xxxxxxxxx > cc: linux-block@xxxxxxxxxxxxxxx > cc: linux-cifs@xxxxxxxxxxxxxxx > cc: linux-fsdevel@xxxxxxxxxxxxxxx > > 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, >
