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authorDavid Howells <dhowells@redhat.com>2023-05-22 14:50:18 +0100
committerJens Axboe <axboe@kernel.dk>2023-05-24 08:42:17 -0600
commit9eee8bd81421c5e961cbb1a3c3fa1a06fad545e8 (patch)
tree47742122776e33a8ad5aee574d0452f5e5b74619 /fs/splice.c
parent3fc40265ae2b48a7475c41c5c0b256374c419f4b (diff)
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 Link: https://lore.kernel.org/r/20230522135018.2742245-32-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/splice.c')
-rw-r--r--fs/splice.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/fs/splice.c b/fs/splice.c
index 9be4cb3b9879..2420ead610a7 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.
+ *
+ * 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,