pipe: add pipe_buf_confirm() helper

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 18 insertions, 10 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index d82414a1f936..e5d5cc922c70 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -728,7 +728,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
                 struct pipe_buffer *buf = cs->pipebufs;
 
                 if (!cs->write) {
-                        err = buf->ops->confirm(cs->pipe, buf);
+                        err = pipe_buf_confirm(cs->pipe, buf);
                         if (err)
                                 return err;
 
@@ -828,7 +828,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
 
         fuse_copy_finish(cs);
 
-        err = buf->ops->confirm(cs->pipe, buf);
+        err = pipe_buf_confirm(cs->pipe, buf);
         if (err)
                 return err;
 
diff --git a/fs/pipe.c b/fs/pipe.c
index 67b5f1923835..4fc422f0dea8 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -267,7 +267,6 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to)
                 if (bufs) {
                         int curbuf = pipe->curbuf;
                         struct pipe_buffer *buf = pipe->bufs + curbuf;
-                        const struct pipe_buf_operations *ops = buf->ops;
                         size_t chars = buf->len;
                         size_t written;
                         int error;
@@ -275,7 +274,7 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to)
                         if (chars > total_len)
                                 chars = total_len;
 
-                        error = ops->confirm(pipe, buf);
+                        error = pipe_buf_confirm(pipe, buf);
                         if (error) {
                                 if (!ret)
                                         ret = error;
@@ -382,11 +381,10 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
                 int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &
                                                         (pipe->buffers - 1);
                 struct pipe_buffer *buf = pipe->bufs + lastbuf;
-                const struct pipe_buf_operations *ops = buf->ops;
                 int offset = buf->offset + buf->len;
 
-                if (ops->can_merge && offset + chars <= PAGE_SIZE) {
-                        ret = ops->confirm(pipe, buf);
+                if (buf->ops->can_merge && offset + chars <= PAGE_SIZE) {
+                        ret = pipe_buf_confirm(pipe, buf);
                         if (ret)
                                 goto out;
 
diff --git a/fs/splice.c b/fs/splice.c
index ae90cd1d2999..aa38901a4f10 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -520,7 +520,7 @@ static int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_des
                 if (sd->len > sd->total_len)
                         sd->len = sd->total_len;
 
-                ret = buf->ops->confirm(pipe, buf);
+                ret = pipe_buf_confirm(pipe, buf);
                 if (unlikely(ret)) {
                         if (ret == -ENODATA)
                                 ret = 0;
@@ -759,7 +759,7 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
                         if (idx == pipe->buffers - 1)
                                 idx = -1;
 
-                        ret = buf->ops->confirm(pipe, buf);
+                        ret = pipe_buf_confirm(pipe, buf);
                         if (unlikely(ret)) {
                                 if (ret == -ENODATA)
                                         ret = 0;
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index d24fa6da6ae3..654413334537 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -140,6 +140,17 @@ static inline void pipe_buf_release(struct pipe_inode_info *pipe,
         ops->release(pipe, buf);
 }
 
+/**
+ * pipe_buf_confirm - verify contents of the pipe buffer
+ * @pipe:       the pipe that the buffer belongs to
+ * @buf:        the buffer to confirm
+ */
+static inline int pipe_buf_confirm(struct pipe_inode_info *pipe,
+                                   struct pipe_buffer *buf)
+{
+        return buf->ops->confirm(pipe, buf);
+}
+
 /* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
    memory allocation, whereas PIPE_BUF makes atomicity guarantees.  */
 #define PIPE_SIZE               PAGE_SIZE
@@ -154,7 +165,6 @@ extern unsigned long pipe_user_pages_hard;
 extern unsigned long pipe_user_pages_soft;
 int pipe_proc_fn(struct ctl_table *, int, void __user *, size_t *, loff_t *);
 
-
 /* Drop the inode semaphore and wait for a pipe event, atomically */
 void pipe_wait(struct pipe_inode_info *pipe);