Commit 313d64a3 authored by Al Viro's avatar Al Viro
Browse files

do_splice_to(): move the logics for limiting the read length in 



Both callers have the identical logics limiting the amount of
data we try to read into pipe - no more than would fit into
that pipe.  Move that into do_splice_to() itself.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 5c8fe583

fs/splice.c

+7 −14
Original line number Diff line number Diff line
@@ -771,11 +771,16 @@ static long do_splice_to(struct file *in, loff_t *ppos, 
			 struct pipe_inode_info *pipe, size_t len,

			 unsigned int flags)

{

	unsigned int p_space;

	int ret;



	if (unlikely(!(in->f_mode & FMODE_READ)))

		return -EBADF;



	/* Don't try to read more the pipe has space for. */

	p_space = pipe->max_usage - pipe_occupancy(pipe->head, pipe->tail);

	len = min_t(size_t, len, p_space << PAGE_SHIFT);



	ret = rw_verify_area(READ, in, ppos, len);

	if (unlikely(ret < 0))

		return ret;
@@ -856,15 +861,10 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, 
	WARN_ON_ONCE(!pipe_empty(pipe->head, pipe->tail));



	while (len) {

		unsigned int p_space;

		size_t read_len;

		loff_t pos = sd->pos, prev_pos = pos;



		/* Don't try to read more the pipe has space for. */

		p_space = pipe->max_usage -

			pipe_occupancy(pipe->head, pipe->tail);

		read_len = min_t(size_t, len, p_space << PAGE_SHIFT);

		ret = do_splice_to(in, &pos, pipe, read_len, flags);

		ret = do_splice_to(in, &pos, pipe, len, flags);

		if (unlikely(ret <= 0))

			goto out_release;
@@ -1083,15 +1083,8 @@ long do_splice(struct file *in, loff_t *off_in, struct file *out, 


		pipe_lock(opipe);

		ret = wait_for_space(opipe, flags);

		if (!ret) {

			unsigned int p_space;



			/* Don't try to read more the pipe has space for. */

			p_space = opipe->max_usage - pipe_occupancy(opipe->head, opipe->tail);

			len = min_t(size_t, len, p_space << PAGE_SHIFT);



		if (!ret)

			ret = do_splice_to(in, &offset, opipe, len, flags);

		}

		pipe_unlock(opipe);

		if (ret > 0)

			wakeup_pipe_readers(opipe);