sh: convert /proc/cpu/aligmnent, /proc/cpu/kernel_alignment to seq_file

[safe/jmp/linux-2.6] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 13414ec..ae17d02 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -68,8 +68,8 @@ void pipe_double_lock(struct pipe_inode_info *pipe1,
                pipe_lock_nested(pipe1, I_MUTEX_PARENT);
                pipe_lock_nested(pipe2, I_MUTEX_CHILD);
        } else {
-               pipe_lock_nested(pipe2, I_MUTEX_CHILD);
-               pipe_lock_nested(pipe1, I_MUTEX_PARENT);
+               pipe_lock_nested(pipe2, I_MUTEX_PARENT);
+               pipe_lock_nested(pipe1, I_MUTEX_CHILD);
        }
 }
 
@@ -302,6 +302,20 @@ int generic_pipe_buf_confirm(struct pipe_inode_info *info,
        return 0;
 }
 
+/**
+ * generic_pipe_buf_release - put a reference to a &struct pipe_buffer
+ * @pipe:      the pipe that the buffer belongs to
+ * @buf:       the buffer to put a reference to
+ *
+ * Description:
+ *     This function releases a reference to @buf.
+ */
+void generic_pipe_buf_release(struct pipe_inode_info *pipe,
+                             struct pipe_buffer *buf)
+{
+       page_cache_release(buf->page);
+}
+
 static const struct pipe_buf_operations anon_pipe_buf_ops = {
        .can_merge = 1,
        .map = generic_pipe_buf_map,
@@ -763,36 +777,55 @@ pipe_rdwr_release(struct inode *inode, struct file *filp)
 static int
 pipe_read_open(struct inode *inode, struct file *filp)
 {
-       /* We could have perhaps used atomic_t, but this and friends
-          below are the only places.  So it doesn't seem worthwhile.  */
+       int ret = -ENOENT;
+
        mutex_lock(&inode->i_mutex);
-       inode->i_pipe->readers++;
+
+       if (inode->i_pipe) {
+               ret = 0;
+               inode->i_pipe->readers++;
+       }
+
        mutex_unlock(&inode->i_mutex);
 
-       return 0;
+       return ret;
 }
 
 static int
 pipe_write_open(struct inode *inode, struct file *filp)
 {
+       int ret = -ENOENT;
+
        mutex_lock(&inode->i_mutex);
-       inode->i_pipe->writers++;
+
+       if (inode->i_pipe) {
+               ret = 0;
+               inode->i_pipe->writers++;
+       }
+
        mutex_unlock(&inode->i_mutex);
 
-       return 0;
+       return ret;
 }
 
 static int
 pipe_rdwr_open(struct inode *inode, struct file *filp)
 {
+       int ret = -ENOENT;
+
        mutex_lock(&inode->i_mutex);
-       if (filp->f_mode & FMODE_READ)
-               inode->i_pipe->readers++;
-       if (filp->f_mode & FMODE_WRITE)
-               inode->i_pipe->writers++;
+
+       if (inode->i_pipe) {
+               ret = 0;
+               if (filp->f_mode & FMODE_READ)
+                       inode->i_pipe->readers++;
+               if (filp->f_mode & FMODE_WRITE)
+                       inode->i_pipe->writers++;
+       }
+
        mutex_unlock(&inode->i_mutex);
 
-       return 0;
+       return ret;
 }
 
 /*