[PATCH] introduce a "kernel-internal pipe object" abstraction

[linux-2.6] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 109a102c150d3483da33f08d4ce69768de69b751..705b4869262765c17124b2c361359686dce6e202 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -36,7 +36,7 @@
  */
 
 /* Drop the inode semaphore and wait for a pipe event, atomically */
-void pipe_wait(struct inode * inode)
+void pipe_wait(struct pipe_inode_info *pipe)
 {
        DEFINE_WAIT(wait);
 
@@ -44,11 +44,13 @@ void pipe_wait(struct inode * inode)
         * Pipes are system-local resources, so sleeping on them
         * is considered a noninteractive wait:
         */
-       prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE);
-       mutex_unlock(PIPE_MUTEX(*inode));
+       prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE);
+       if (pipe->inode)
+               mutex_unlock(&pipe->inode->i_mutex);
        schedule();
-       finish_wait(PIPE_WAIT(*inode), &wait);
-       mutex_lock(PIPE_MUTEX(*inode));
+       finish_wait(&pipe->wait, &wait);
+       if (pipe->inode)
+               mutex_lock(&pipe->inode->i_mutex);
 }
 
 static int
@@ -95,6 +97,8 @@ static void anon_pipe_buf_release(struct pipe_inode_info *info, struct pipe_buff
 {
        struct page *page = buf->page;
 
+       buf->flags &= ~PIPE_BUF_FLAG_STOLEN;
+
        /*
         * If nobody else uses this page, and we don't already have a
         * temporary page, let's keep track of it as a one-deep
@@ -124,7 +128,7 @@ static void anon_pipe_buf_unmap(struct pipe_inode_info *info, struct pipe_buffer
 static int anon_pipe_buf_steal(struct pipe_inode_info *info,
                               struct pipe_buffer *buf)
 {
-       buf->stolen = 1;
+       buf->flags |= PIPE_BUF_FLAG_STOLEN;
        return 0;
 }
 
@@ -221,7 +225,7 @@ pipe_readv(struct file *filp, const struct iovec *_iov,
                        wake_up_interruptible_sync(PIPE_WAIT(*inode));
                        kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT);
                }
-               pipe_wait(inode);
+               pipe_wait(inode->i_pipe);
        }
        mutex_unlock(PIPE_MUTEX(*inode));
        /* Signal writers asynchronously that there is more room.  */
@@ -368,7 +372,7 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
                        do_wakeup = 0;
                }
                PIPE_WAITING_WRITERS(*inode)++;
-               pipe_wait(inode);
+               pipe_wait(inode->i_pipe);
                PIPE_WAITING_WRITERS(*inode)--;
        }
 out:
@@ -673,6 +677,20 @@ static struct file_operations rdwr_pipe_fops = {
        .fasync         = pipe_rdwr_fasync,
 };
 
+struct pipe_inode_info * alloc_pipe_info(struct inode *inode)
+{
+       struct pipe_inode_info *info;
+
+       info = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);
+       if (info) {
+               init_waitqueue_head(&info->wait);
+               info->r_counter = info->w_counter = 1;
+               info->inode = inode;
+       }
+
+       return info;
+}
+
 void free_pipe_info(struct inode *inode)
 {
        int i;
@@ -689,23 +707,6 @@ void free_pipe_info(struct inode *inode)
        kfree(info);
 }
 
-struct inode* pipe_new(struct inode* inode)
-{
-       struct pipe_inode_info *info;
-
-       info = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);
-       if (!info)
-               goto fail_page;
-       inode->i_pipe = info;
-
-       init_waitqueue_head(PIPE_WAIT(*inode));
-       PIPE_RCOUNTER(*inode) = PIPE_WCOUNTER(*inode) = 1;
-
-       return inode;
-fail_page:
-       return NULL;
-}
-
 static struct vfsmount *pipe_mnt __read_mostly;
 static int pipefs_delete_dentry(struct dentry *dentry)
 {
@@ -722,8 +723,10 @@ static struct inode * get_pipe_inode(void)
        if (!inode)
                goto fail_inode;
 
-       if(!pipe_new(inode))
+       inode->i_pipe = alloc_pipe_info(inode);
+       if (!inode->i_pipe)
                goto fail_iput;
+
        PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 1;
        inode->i_fop = &rdwr_pipe_fops;