pipe: add pipe_buf_release() helper

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

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index b50220c..d82414a 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1985,10 +1985,9 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
 
        ret = fuse_dev_do_write(fud, &cs, len);
 
-       for (idx = 0; idx < nbuf; idx++) {
-               struct pipe_buffer *buf = &bufs[idx];
-               buf->ops->release(pipe, buf);
-       }
+       for (idx = 0; idx < nbuf; idx++)
+               pipe_buf_release(pipe, &bufs[idx]);
+
 out:
        kfree(bufs);
        return ret;

diff --git a/fs/pipe.c b/fs/pipe.c
index 4ebe6b2..67b5f19 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -299,8 +299,7 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to)
                        }
 
                        if (!buf->len) {
-                               buf->ops = NULL;
-                               ops->release(pipe, buf);
+                               pipe_buf_release(pipe, buf);
                                curbuf = (curbuf + 1) & (pipe->buffers - 1);
                                pipe->curbuf = curbuf;
                                pipe->nrbufs = --bufs;
@@ -664,7 +663,7 @@ void free_pipe_info(struct pipe_inode_info *pipe)
        for (i = 0; i < pipe->buffers; i++) {
                struct pipe_buffer *buf = pipe->bufs + i;
                if (buf->ops)
-                       buf->ops->release(pipe, buf);
+                       pipe_buf_release(pipe, buf);
        }
        if (pipe->tmp_page)
                __free_page(pipe->tmp_page);

diff --git a/fs/splice.c b/fs/splice.c
index 188a386..ae90cd1 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -238,8 +238,7 @@ ssize_t add_to_pipe(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
                pipe->nrbufs++;
                return buf->len;
        }
-       buf->ops->release(pipe, buf);
-       buf->ops = NULL;
+       pipe_buf_release(pipe, buf);
        return ret;
 }
 EXPORT_SYMBOL(add_to_pipe);
@@ -516,7 +515,6 @@ static int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_des
 
        while (pipe->nrbufs) {
                struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
-               const struct pipe_buf_operations *ops = buf->ops;
 
                sd->len = buf->len;
                if (sd->len > sd->total_len)
@@ -542,8 +540,7 @@ static int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_des
                sd->total_len -= ret;
 
                if (!buf->len) {
-                       buf->ops = NULL;
-                       ops->release(pipe, buf);
+                       pipe_buf_release(pipe, buf);
                        pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
                        pipe->nrbufs--;
                        if (pipe->files)
@@ -789,11 +786,9 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
                while (ret) {
                        struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
                        if (ret >= buf->len) {
-                               const struct pipe_buf_operations *ops = buf->ops;
                                ret -= buf->len;
                                buf->len = 0;
-                               buf->ops = NULL;
-                               ops->release(pipe, buf);
+                               pipe_buf_release(pipe, buf);
                                pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
                                pipe->nrbufs--;
                                if (pipe->files)
@@ -1032,10 +1027,8 @@ out_release:
        for (i = 0; i < pipe->buffers; i++) {
                struct pipe_buffer *buf = pipe->bufs + i;
 
-               if (buf->ops) {
-                       buf->ops->release(pipe, buf);
-                       buf->ops = NULL;
-               }
+               if (buf->ops)
+                       pipe_buf_release(pipe, buf);
        }
 
        if (!bytes)

diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 10876f3..d24fa6d 100644 (file)
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -126,6 +126,20 @@ static inline void pipe_buf_get(struct pipe_inode_info *pipe,
        buf->ops->get(pipe, buf);
 }
 
+/**
+ * pipe_buf_release - put a reference to a pipe_buffer
+ * @pipe:      the pipe that the buffer belongs to
+ * @buf:       the buffer to put a reference to
+ */
+static inline void pipe_buf_release(struct pipe_inode_info *pipe,
+                                   struct pipe_buffer *buf)
+{
+       const struct pipe_buf_operations *ops = buf->ops;
+
+       buf->ops = NULL;
+       ops->release(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

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 659eaaf..48b8c27 100644 (file)
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -709,9 +709,7 @@ static void pipe_advance(struct iov_iter *i, size_t size)
                int unused = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
                /* [curbuf,unused) is in use.  Free [idx,unused) */
                while (idx != unused) {
-                       buf = &pipe->bufs[idx];
-                       buf->ops->release(pipe, buf);
-                       buf->ops = NULL;
+                       pipe_buf_release(pipe, &pipe->bufs[idx]);
                        idx = next_idx(idx, pipe);
                        pipe->nrbufs--;
                }