fs: prevent page refcount overflow in pipe_buf_get

[mirror_ubuntu-bionic-kernel.git] / include / linux / pipe_fs_i.h

diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index ac6f64dc5c07863215808475e2aff12a21584453..4e3776429d6303fc16713872cf412f7defbe4c31 100644 (file)
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -108,18 +108,20 @@ struct pipe_buf_operations {
        /*
         * Get a reference to the pipe buffer.
         */
-       void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
+       bool (*get)(struct pipe_inode_info *, struct pipe_buffer *);
 };
 
 /**
  * pipe_buf_get - get a reference to a pipe_buffer
  * @pipe:      the pipe that the buffer belongs to
  * @buf:       the buffer to get a reference to
+ *
+ * Return: %true if the reference was successfully obtained.
  */
-static inline void pipe_buf_get(struct pipe_inode_info *pipe,
+static inline __must_check bool pipe_buf_get(struct pipe_inode_info *pipe,
                                struct pipe_buffer *buf)
 {
-       buf->ops->get(pipe, buf);
+       return buf->ops->get(pipe, buf);
 }
 
 /**
@@ -179,7 +181,7 @@ struct pipe_inode_info *alloc_pipe_info(void);
 void free_pipe_info(struct pipe_inode_info *);
 
 /* Generic pipe buffer ops functions */
-void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
+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 *);