From: Christoph Hellwig <hch@lst.de>
Date: Wed, 20 May 2020 15:58:14 +0000 (+0200)
Subject: fs: make the pipe_buf_operations ->steal operation optional
X-Git-Tag: v5.8-rc1~167^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=76887c256744740d6121af9bc4aa787712a1f694;p=thirdparty%2Flinux.git

fs: make the pipe_buf_operations ->steal operation optional

Just return 1 for failure if it is not present.

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

diff --git a/fs/splice.c b/fs/splice.c
index fb9670e7fc1f0..6c19bda274c8f 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -337,17 +337,10 @@ const struct pipe_buf_operations default_pipe_buf_ops = {
 	.get = generic_pipe_buf_get,
 };
 
-int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
-			     struct pipe_buffer *buf)
-{
-	return 1;
-}
-
 /* Pipe buffer operations for a socket and similar. */
 const struct pipe_buf_operations nosteal_pipe_buf_ops = {
 	.confirm = generic_pipe_buf_confirm,
 	.release = generic_pipe_buf_release,
-	.steal = generic_pipe_buf_nosteal,
 	.get = generic_pipe_buf_get,
 };
 EXPORT_SYMBOL(nosteal_pipe_buf_ops);
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 3f7b07b388249..e022b24593015 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -206,6 +206,8 @@ static inline int pipe_buf_confirm(struct pipe_inode_info *pipe,
 static inline int pipe_buf_steal(struct pipe_inode_info *pipe,
 				 struct pipe_buffer *buf)
 {
+	if (!buf->ops->steal)
+		return 1;
 	return buf->ops->steal(pipe, buf);
 }
 
@@ -232,7 +234,6 @@ void free_pipe_info(struct pipe_inode_info *);
 bool generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
 int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *);
 int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
-int generic_pipe_buf_nosteal(struct pipe_inode_info *, struct pipe_buffer *);
 void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);
 
 extern const struct pipe_buf_operations nosteal_pipe_buf_ops;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bc9783797d275..29fa25cfb6c26 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7576,7 +7576,6 @@ static bool buffer_pipe_buf_get(struct pipe_inode_info *pipe,
 static const struct pipe_buf_operations buffer_pipe_buf_ops = {
 	.confirm		= generic_pipe_buf_confirm,
 	.release		= buffer_pipe_buf_release,
-	.steal			= generic_pipe_buf_nosteal,
 	.get			= buffer_pipe_buf_get,
 };
 
diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
index 39d7b34d06d23..5fe25279702d2 100644
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -129,16 +129,9 @@ out:
 	sock_put(sk);
 }
 
-static int smc_rx_pipe_buf_nosteal(struct pipe_inode_info *pipe,
-				   struct pipe_buffer *buf)
-{
-	return 1;
-}
-
 static const struct pipe_buf_operations smc_pipe_ops = {
 	.confirm = generic_pipe_buf_confirm,
 	.release = smc_rx_pipe_buf_release,
-	.steal = smc_rx_pipe_buf_nosteal,
 	.get = generic_pipe_buf_get
 };