[Devel] [PATCH 3/6] SUNRPC: cleanup PipeFS redundant RPC inode usage

[Stanislav Kinsbursky]

This patch removes redundant RPC inode references from PipeFS. These places are
actually where pipes operations are performed.

Signed-off-by: Stanislav Kinsbursky <skinsbursky at parallels.com>

---
 net/sunrpc/rpc_pipe.c |   93 ++++++++++++++++++++++++-------------------------
 1 files changed, 46 insertions(+), 47 deletions(-)

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index a95ba18..edf140a 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -112,28 +112,28 @@ rpc_timeout_upcall_queue(struct work_struct *work)
 int
 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
 {
-	struct rpc_inode *rpci = RPC_I(inode);
+	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 	int res = -EPIPE;
 
-	spin_lock(&rpci->pipe->lock);
-	if (rpci->pipe->ops == NULL)
+	spin_lock(&pipe->lock);
+	if (pipe->ops == NULL)
 		goto out;
-	if (rpci->pipe->nreaders) {
-		list_add_tail(&msg->list, &rpci->pipe->pipe);
-		rpci->pipe->pipelen += msg->len;
+	if (pipe->nreaders) {
+		list_add_tail(&msg->list, &pipe->pipe);
+		pipe->pipelen += msg->len;
 		res = 0;
-	} else if (rpci->pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
-		if (list_empty(&rpci->pipe->pipe))
+	} else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
+		if (list_empty(&pipe->pipe))
 			queue_delayed_work(rpciod_workqueue,
-					&rpci->pipe->queue_timeout,
+					&pipe->queue_timeout,
 					RPC_UPCALL_TIMEOUT);
-		list_add_tail(&msg->list, &rpci->pipe->pipe);
-		rpci->pipe->pipelen += msg->len;
+		list_add_tail(&msg->list, &pipe->pipe);
+		pipe->pipelen += msg->len;
 		res = 0;
 	}
 out:
-	spin_unlock(&rpci->pipe->lock);
-	wake_up(&rpci->pipe->waitq);
+	spin_unlock(&pipe->lock);
+	wake_up(&pipe->waitq);
 	return res;
 }
 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
@@ -201,23 +201,23 @@ rpc_destroy_inode(struct inode *inode)
 static int
 rpc_pipe_open(struct inode *inode, struct file *filp)
 {
-	struct rpc_inode *rpci = RPC_I(inode);
+	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 	int first_open;
 	int res = -ENXIO;
 
 	mutex_lock(&inode->i_mutex);
-	if (rpci->pipe->ops == NULL)
+	if (pipe->ops == NULL)
 		goto out;
-	first_open = rpci->pipe->nreaders == 0 && rpci->pipe->nwriters == 0;
-	if (first_open && rpci->pipe->ops->open_pipe) {
-		res = rpci->pipe->ops->open_pipe(inode);
+	first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
+	if (first_open && pipe->ops->open_pipe) {
+		res = pipe->ops->open_pipe(inode);
 		if (res)
 			goto out;
 	}
 	if (filp->f_mode & FMODE_READ)
-		rpci->pipe->nreaders++;
+		pipe->nreaders++;
 	if (filp->f_mode & FMODE_WRITE)
-		rpci->pipe->nwriters++;
+		pipe->nwriters++;
 	res = 0;
 out:
 	mutex_unlock(&inode->i_mutex);
@@ -268,39 +268,39 @@ static ssize_t
 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 {
 	struct inode *inode = filp->f_path.dentry->d_inode;
-	struct rpc_inode *rpci = RPC_I(inode);
+	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 	struct rpc_pipe_msg *msg;
 	int res = 0;
 
 	mutex_lock(&inode->i_mutex);
-	if (rpci->pipe->ops == NULL) {
+	if (pipe->ops == NULL) {
 		res = -EPIPE;
 		goto out_unlock;
 	}
 	msg = filp->private_data;
 	if (msg == NULL) {
-		spin_lock(&rpci->pipe->lock);
-		if (!list_empty(&rpci->pipe->pipe)) {
-			msg = list_entry(rpci->pipe->pipe.next,
+		spin_lock(&pipe->lock);
+		if (!list_empty(&pipe->pipe)) {
+			msg = list_entry(pipe->pipe.next,
 					struct rpc_pipe_msg,
 					list);
-			list_move(&msg->list, &rpci->pipe->in_upcall);
-			rpci->pipe->pipelen -= msg->len;
+			list_move(&msg->list, &pipe->in_upcall);
+			pipe->pipelen -= msg->len;
 			filp->private_data = msg;
 			msg->copied = 0;
 		}
-		spin_unlock(&rpci->pipe->lock);
+		spin_unlock(&pipe->lock);
 		if (msg == NULL)
 			goto out_unlock;
 	}
 	/* NOTE: it is up to the callback to update msg->copied */
-	res = rpci->pipe->ops->upcall(filp, msg, buf, len);
+	res = pipe->ops->upcall(filp, msg, buf, len);
 	if (res < 0 || msg->len == msg->copied) {
 		filp->private_data = NULL;
-		spin_lock(&rpci->pipe->lock);
+		spin_lock(&pipe->lock);
 		list_del_init(&msg->list);
-		spin_unlock(&rpci->pipe->lock);
-		rpci->pipe->ops->destroy_msg(msg);
+		spin_unlock(&pipe->lock);
+		pipe->ops->destroy_msg(msg);
 	}
 out_unlock:
 	mutex_unlock(&inode->i_mutex);
@@ -311,13 +311,13 @@ static ssize_t
 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 {
 	struct inode *inode = filp->f_path.dentry->d_inode;
-	struct rpc_inode *rpci = RPC_I(inode);
+	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 	int res;
 
 	mutex_lock(&inode->i_mutex);
 	res = -EPIPE;
-	if (rpci->pipe->ops != NULL)
-		res = rpci->pipe->ops->downcall(filp, buf, len);
+	if (pipe->ops != NULL)
+		res = pipe->ops->downcall(filp, buf, len);
 	mutex_unlock(&inode->i_mutex);
 	return res;
 }
@@ -325,16 +325,15 @@ rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *of
 static unsigned int
 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 {
-	struct rpc_inode *rpci;
+	struct rpc_pipe *pipe = RPC_I(filp->f_path.dentry->d_inode)->pipe;
 	unsigned int mask = 0;
 
-	rpci = RPC_I(filp->f_path.dentry->d_inode);
-	poll_wait(filp, &rpci->pipe->waitq, wait);
+	poll_wait(filp, &pipe->waitq, wait);
 
 	mask = POLLOUT | POLLWRNORM;
-	if (rpci->pipe->ops == NULL)
+	if (pipe->ops == NULL)
 		mask |= POLLERR | POLLHUP;
-	if (filp->private_data || !list_empty(&rpci->pipe->pipe))
+	if (filp->private_data || !list_empty(&pipe->pipe))
 		mask |= POLLIN | POLLRDNORM;
 	return mask;
 }
@@ -343,23 +342,23 @@ static long
 rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = filp->f_path.dentry->d_inode;
-	struct rpc_inode *rpci = RPC_I(inode);
+	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 	int len;
 
 	switch (cmd) {
 	case FIONREAD:
-		spin_lock(&rpci->pipe->lock);
-		if (rpci->pipe->ops == NULL) {
-			spin_unlock(&rpci->pipe->lock);
+		spin_lock(&pipe->lock);
+		if (pipe->ops == NULL) {
+			spin_unlock(&pipe->lock);
 			return -EPIPE;
 		}
-		len = rpci->pipe->pipelen;
+		len = pipe->pipelen;
 		if (filp->private_data) {
 			struct rpc_pipe_msg *msg;
 			msg = filp->private_data;
 			len += msg->len - msg->copied;
 		}
-		spin_unlock(&rpci->pipe->lock);
+		spin_unlock(&pipe->lock);
 		return put_user(len, (int __user *)arg);
 	default:
 		return -EINVAL;
@@ -789,7 +788,7 @@ static int rpc_rmdir_depopulate(struct dentry *dentry,
  * @private: private data to associate with the pipe, for the caller's use
  * @ops: operations defining the behavior of the pipe: upcall, downcall,
  *	release_pipe, open_pipe, and destroy_msg.
- * @flags: rpc_inode flags
+ * @flags: rpc_pipe flags
  *
  * Data is made available for userspace to read by calls to
  * rpc_queue_upcall().  The actual reads will result in calls to