[PATCH 4/5] pipe: move wait_for_space to fs/pipe.c and rename it

[Askar Safin <safinaskar@gmail.com>]

This is needed, because I plan to use it in fs/read_write.c.

Signed-off-by: Askar Safin <safinaskar@gmail.com>
---
 fs/pipe.c                 | 17 +++++++++++++++++
 fs/splice.c               | 19 +------------------
 include/linux/pipe_fs_i.h |  2 ++
 3 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/fs/pipe.c b/fs/pipe.c
index 9841648c9..c0ccf21b9 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1451,6 +1451,23 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned int arg)
 	return ret;
 }
 
+int pipe_wait_for_space(struct pipe_inode_info *pipe, bool non_block)
+{
+	for (;;) {
+		if (unlikely(!pipe->readers)) {
+			send_sig(SIGPIPE, current, 0);
+			return -EPIPE;
+		}
+		if (!pipe_is_full(pipe))
+			return 0;
+		if (non_block)
+			return -EAGAIN;
+		if (signal_pending(current))
+			return -ERESTARTSYS;
+		pipe_wait_writable(pipe);
+	}
+}
+
 static const struct super_operations pipefs_ops = {
 	.destroy_inode = free_inode_nonrcu,
 	.statfs = simple_statfs,
diff --git a/fs/splice.c b/fs/splice.c
index 707db2c2c..d12243d19 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1239,23 +1239,6 @@ ssize_t splice_file_range(struct file *in, loff_t *ppos, struct file *out,
 }
 EXPORT_SYMBOL(splice_file_range);
 
-static int wait_for_space(struct pipe_inode_info *pipe, bool non_block)
-{
-	for (;;) {
-		if (unlikely(!pipe->readers)) {
-			send_sig(SIGPIPE, current, 0);
-			return -EPIPE;
-		}
-		if (!pipe_is_full(pipe))
-			return 0;
-		if (non_block)
-			return -EAGAIN;
-		if (signal_pending(current))
-			return -ERESTARTSYS;
-		pipe_wait_writable(pipe);
-	}
-}
-
 static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
 			       struct pipe_inode_info *opipe,
 			       size_t len, unsigned int flags);
@@ -1268,7 +1251,7 @@ ssize_t splice_file_to_pipe(struct file *in,
 	ssize_t ret;
 
 	pipe_lock(opipe);
-	ret = wait_for_space(opipe, flags & SPLICE_F_NONBLOCK);
+	ret = pipe_wait_for_space(opipe, flags & SPLICE_F_NONBLOCK);
 	if (!ret)
 		ret = do_splice_read(in, offset, opipe, len, flags);
 	pipe_unlock(opipe);
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index a1eeed800..be653625d 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -335,4 +335,6 @@ struct pipe_inode_info *get_pipe_info(struct file *file, bool for_splice);
 int create_pipe_files(struct file **, int);
 unsigned int round_pipe_size(unsigned int size);
 
+int pipe_wait_for_space(struct pipe_inode_info *pipe, bool non_block);
+
 #endif
-- 
2.47.3