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Commit 29e35094 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

splice: add SPLICE_F_NONBLOCK flag 



It doesn't make the splice itself necessarily nonblocking (because the
actual file descriptors that are spliced from/to may block unless they
have the O_NONBLOCK flag set), but it makes the splice pipe operations
nonblocking.

Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b45e516f

fs/splice.c

+21 −4
Original line number Diff line number Diff line
@@ -106,7 +106,7 @@ static struct pipe_buf_operations page_cache_pipe_buf_ops = { 


static ssize_t move_to_pipe(struct inode *inode, struct page **pages,

			    int nr_pages, unsigned long offset,

			    unsigned long len)

			    unsigned long len, unsigned int flags)

{

	struct pipe_inode_info *info;

	int ret, do_wakeup, i;
@@ -159,6 +159,12 @@ static ssize_t move_to_pipe(struct inode *inode, struct page **pages, 
			break;

		}



		if (flags & SPLICE_F_NONBLOCK) {

			if (!ret)

				ret = -EAGAIN;

			break;

		}



		if (signal_pending(current)) {

			if (!ret)

				ret = -ERESTARTSYS;
@@ -191,7 +197,7 @@ static ssize_t move_to_pipe(struct inode *inode, struct page **pages, 
}



static int __generic_file_splice_read(struct file *in, struct inode *pipe,

				      size_t len)

				      size_t len, unsigned int flags)

{

	struct address_space *mapping = in->f_mapping;

	unsigned int offset, nr_pages;
@@ -279,7 +285,7 @@ static int __generic_file_splice_read(struct file *in, struct inode *pipe, 
	 * Now we splice them into the pipe..

	 */

splice_them:

	return move_to_pipe(pipe, pages, i, offset, len);

	return move_to_pipe(pipe, pages, i, offset, len, flags);

}



ssize_t generic_file_splice_read(struct file *in, struct inode *pipe,
@@ -291,7 +297,7 @@ ssize_t generic_file_splice_read(struct file *in, struct inode *pipe, 
	ret = 0;

	spliced = 0;

	while (len) {

		ret = __generic_file_splice_read(in, pipe, len);

		ret = __generic_file_splice_read(in, pipe, len, flags);



		if (ret <= 0)

			break;
@@ -299,6 +305,11 @@ ssize_t generic_file_splice_read(struct file *in, struct inode *pipe, 
		in->f_pos += ret;

		len -= ret;

		spliced += ret;



		if (!(flags & SPLICE_F_NONBLOCK))

			continue;

		ret = -EAGAIN;

		break;

	}



	if (spliced)
@@ -527,6 +538,12 @@ static ssize_t move_from_pipe(struct inode *inode, struct file *out, 
				break;

		}



		if (flags & SPLICE_F_NONBLOCK) {

			if (!ret)

				ret = -EAGAIN;

			break;

		}



		if (signal_pending(current)) {

			if (!ret)

				ret = -ERESTARTSYS;

include/linux/pipe_fs_i.h

+3 −0
Original line number Diff line number Diff line
@@ -60,5 +60,8 @@ void free_pipe_info(struct inode* inode); 
 * add the splice flags here.

 */

#define SPLICE_F_MOVE	(0x01)	/* move pages instead of copying */

#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */

				 /* we may still block on the fd we splice */

				 /* from/to, of course */



#endif