linux-master/fs/splice.c

1281 static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
1308 	struct pipe_inode_info *ipipe;
1317 	ipipe = get_pipe_info(in, true);
1320 	if (ipipe && opipe) {
1325 		if (ipipe == opipe)
1331 		ret = splice_pipe_to_pipe(ipipe, opipe, len, flags);
1332 	} else if (ipipe) {
1354 		ret = do_splice_from(ipipe, out, &offset, len, flags);
1406 	struct pipe_inode_info *ipipe;
1411 	ipipe = get_pipe_info(in, true);
1414 	if (ipipe) {
1737  * Splice contents of ipipe to opipe.
1739 static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
1752 	ret = ipipe_prep(ipipe, flags);
1765 	pipe_double_lock(ipipe, opipe);
1767 	i_tail = ipipe->tail;
1768 	i_mask = ipipe->ring_size - 1;
1782 		i_head = ipipe->head;
1785 		if (pipe_empty(i_head, i_tail) && !ipipe->writers)
1808 			pipe_unlock(ipipe);
1813 		ibuf = &ipipe->bufs[i_tail & i_mask];
1818 			 * Simply move the whole buffer from ipipe to opipe
1823 			ipipe->tail = i_tail;
1833 			if (!pipe_buf_get(ipipe, ibuf)) {
1858 	pipe_unlock(ipipe);
1868 		wakeup_pipe_writers(ipipe);
1874  * Link contents of ipipe to opipe.
1876 static ssize_t link_pipe(struct pipe_inode_info *ipipe,
1891 	pipe_double_lock(ipipe, opipe);
1893 	i_tail = ipipe->tail;
1894 	i_mask = ipipe->ring_size - 1;
1906 		i_head = ipipe->head;
1917 		ibuf = &ipipe->bufs[i_tail & i_mask];
1924 		if (!pipe_buf_get(ipipe, ibuf)) {
1949 	pipe_unlock(ipipe);
1970 	struct pipe_inode_info *ipipe = get_pipe_info(in, true);
1979 	 * Duplicate the contents of ipipe to opipe without actually
1982 	if (ipipe && opipe && ipipe != opipe) {
1987 		 * Keep going, unless we encounter an error. The ipipe/opipe
1990 		ret = ipipe_prep(ipipe, flags);
1994 				ret = link_pipe(ipipe, opipe, len, flags);