fs: rename pipe_buf ->steal to ->try_steal

And replace the arcane return value convention with a simple bool
where true means success and false means failure.

[AV: braino fix folded in]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 37 insertions, 39 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 97eec7522bf2..7a2b2de87b1f 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -805,7 +805,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
 	if (cs->len != PAGE_SIZE)
 		goto out_fallback;
 
-	if (pipe_buf_steal(cs->pipe, buf) != 0)
+	if (!pipe_buf_try_steal(cs->pipe, buf))
 		goto out_fallback;
 
 	newpage = buf->page;
diff --git a/fs/pipe.c b/fs/pipe.c
index 58890897402a..c7c4fb5f345f 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -140,21 +140,20 @@ static void anon_pipe_buf_release(struct pipe_inode_info *pipe,
 		put_page(page);
 }
 
-static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
-			       struct pipe_buffer *buf)
+static bool anon_pipe_buf_try_steal(struct pipe_inode_info *pipe,
+		struct pipe_buffer *buf)
 {
 	struct page *page = buf->page;
 
-	if (page_count(page) == 1) {
-		memcg_kmem_uncharge_page(page, 0);
-		__SetPageLocked(page);
-		return 0;
-	}
-	return 1;
+	if (page_count(page) != 1)
+		return false;
+	memcg_kmem_uncharge_page(page, 0);
+	__SetPageLocked(page);
+	return true;
 }
 
 /**
- * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer
+ * generic_pipe_buf_try_steal - attempt to take ownership of a &pipe_buffer
  * @pipe:	the pipe that the buffer belongs to
  * @buf:	the buffer to attempt to steal
  *
@@ -165,8 +164,8 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
  *	he wishes; the typical use is insertion into a different file
  *	page cache.
  */
-int generic_pipe_buf_steal(struct pipe_inode_info *pipe,
-			   struct pipe_buffer *buf)
+bool generic_pipe_buf_try_steal(struct pipe_inode_info *pipe,
+		struct pipe_buffer *buf)
 {
 	struct page *page = buf->page;
 
@@ -177,12 +176,11 @@ int generic_pipe_buf_steal(struct pipe_inode_info *pipe,
 	 */
 	if (page_count(page) == 1) {
 		lock_page(page);
-		return 0;
+		return true;
 	}
-
-	return 1;
+	return false;
 }
-EXPORT_SYMBOL(generic_pipe_buf_steal);
+EXPORT_SYMBOL(generic_pipe_buf_try_steal);
 
 /**
  * generic_pipe_buf_get - get a reference to a &struct pipe_buffer
@@ -216,9 +214,9 @@ void generic_pipe_buf_release(struct pipe_inode_info *pipe,
 EXPORT_SYMBOL(generic_pipe_buf_release);
 
 static const struct pipe_buf_operations anon_pipe_buf_ops = {
-	.release = anon_pipe_buf_release,
-	.steal = anon_pipe_buf_steal,
-	.get = generic_pipe_buf_get,
+	.release	= anon_pipe_buf_release,
+	.try_steal	= anon_pipe_buf_try_steal,
+	.get		= generic_pipe_buf_get,
 };
 
 /* Done while waiting without holding the pipe lock - thus the READ_ONCE() */
diff --git a/fs/splice.c b/fs/splice.c
index bc834073cf74..2c2f45a9afc0 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -44,8 +44,8 @@
  * addition of remove_mapping(). If success is returned, the caller may
  * attempt to reuse this page for another destination.
  */
-static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
-				     struct pipe_buffer *buf)
+static bool page_cache_pipe_buf_try_steal(struct pipe_inode_info *pipe,
+		struct pipe_buffer *buf)
 {
 	struct page *page = buf->page;
 	struct address_space *mapping;
@@ -76,7 +76,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
 		 */
 		if (remove_mapping(mapping, page)) {
 			buf->flags |= PIPE_BUF_FLAG_LRU;
-			return 0;
+			return true;
 		}
 	}
 
@@ -86,7 +86,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
 	 */
 out_unlock:
 	unlock_page(page);
-	return 1;
+	return false;
 }
 
 static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe,
@@ -139,26 +139,26 @@ error:
 }
 
 const struct pipe_buf_operations page_cache_pipe_buf_ops = {
-	.confirm = page_cache_pipe_buf_confirm,
-	.release = page_cache_pipe_buf_release,
-	.steal = page_cache_pipe_buf_steal,
-	.get = generic_pipe_buf_get,
+	.confirm	= page_cache_pipe_buf_confirm,
+	.release	= page_cache_pipe_buf_release,
+	.try_steal	= page_cache_pipe_buf_try_steal,
+	.get		= generic_pipe_buf_get,
 };
 
-static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,
-				    struct pipe_buffer *buf)
+static bool user_page_pipe_buf_try_steal(struct pipe_inode_info *pipe,
+		struct pipe_buffer *buf)
 {
 	if (!(buf->flags & PIPE_BUF_FLAG_GIFT))
-		return 1;
+		return false;
 
 	buf->flags |= PIPE_BUF_FLAG_LRU;
-	return generic_pipe_buf_steal(pipe, buf);
+	return generic_pipe_buf_try_steal(pipe, buf);
 }
 
 static const struct pipe_buf_operations user_page_pipe_buf_ops = {
-	.release = page_cache_pipe_buf_release,
-	.steal = user_page_pipe_buf_steal,
-	.get = generic_pipe_buf_get,
+	.release	= page_cache_pipe_buf_release,
+	.try_steal	= user_page_pipe_buf_try_steal,
+	.get		= generic_pipe_buf_get,
 };
 
 static void wakeup_pipe_readers(struct pipe_inode_info *pipe)
@@ -330,15 +330,15 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
 EXPORT_SYMBOL(generic_file_splice_read);
 
 const struct pipe_buf_operations default_pipe_buf_ops = {
-	.release = generic_pipe_buf_release,
-	.steal = generic_pipe_buf_steal,
-	.get = generic_pipe_buf_get,
+	.release	= generic_pipe_buf_release,
+	.try_steal	= generic_pipe_buf_try_steal,
+	.get		= generic_pipe_buf_get,
 };
 
 /* Pipe buffer operations for a socket and similar. */
 const struct pipe_buf_operations nosteal_pipe_buf_ops = {
-	.release = generic_pipe_buf_release,
-	.get = generic_pipe_buf_get,
+	.release	= generic_pipe_buf_release,
+	.get		= generic_pipe_buf_get,
 };
 EXPORT_SYMBOL(nosteal_pipe_buf_ops);