SUNRPC: split SUNPRC PipeFS dentry and private pipe data creation

This patch is a final step towards to removing PipeFS inode references from
kernel code other than PipeFS itself. It makes all kernel SUNRPC PipeFS users
depends on pipe private data, which state depend on their specific operations,
etc.
This patch completes SUNRPC PipeFS preparations and allows to create pipe
private data and PipeFS dentries independently.
Next step will be making SUNPRC PipeFS dentries allocated by SUNRPC PipeFS
network namespace aware routines.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 67 insertions, 41 deletions

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 304b8309f21..f684ce60666 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -81,7 +81,7 @@ struct gss_auth {
 	 * mechanism (for example, "krb5") and exists for
 	 * backwards-compatibility with older gssd's.
 	 */
-	struct dentry *dentry[2];
+	struct rpc_pipe *pipe[2];
 };
 
 /* pipe_version >= 0 if and only if someone has a pipe open. */
@@ -449,7 +449,7 @@ gss_alloc_msg(struct gss_auth *gss_auth, struct rpc_clnt *clnt,
 		kfree(gss_msg);
 		return ERR_PTR(vers);
 	}
-	gss_msg->pipe = RPC_I(gss_auth->dentry[vers]->d_inode)->pipe;
+	gss_msg->pipe = gss_auth->pipe[vers];
 	INIT_LIST_HEAD(&gss_msg->list);
 	rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 	init_waitqueue_head(&gss_msg->waitqueue);
@@ -799,21 +799,33 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 	 * that we supported only the old pipe.  So we instead create
 	 * the new pipe first.
 	 */
-	gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry,
-					 "gssd",
-					 clnt, &gss_upcall_ops_v1,
-					 RPC_PIPE_WAIT_FOR_OPEN);
-	if (IS_ERR(gss_auth->dentry[1])) {
-		err = PTR_ERR(gss_auth->dentry[1]);
+	gss_auth->pipe[1] = rpc_mkpipe_data(&gss_upcall_ops_v1,
+					    RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(gss_auth->pipe[1])) {
+		err = PTR_ERR(gss_auth->pipe[1]);
 		goto err_put_mech;
 	}
 
-	gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry,
-					 gss_auth->mech->gm_name,
-					 clnt, &gss_upcall_ops_v0,
-					 RPC_PIPE_WAIT_FOR_OPEN);
-	if (IS_ERR(gss_auth->dentry[0])) {
-		err = PTR_ERR(gss_auth->dentry[0]);
+	gss_auth->pipe[0] = rpc_mkpipe_data(&gss_upcall_ops_v0,
+					    RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(gss_auth->pipe[0])) {
+		err = PTR_ERR(gss_auth->pipe[0]);
+		goto err_destroy_pipe_1;
+	}
+
+	gss_auth->pipe[1]->dentry = rpc_mkpipe_dentry(clnt->cl_path.dentry,
+						      "gssd",
+						      clnt, gss_auth->pipe[1]);
+	if (IS_ERR(gss_auth->pipe[1]->dentry)) {
+		err = PTR_ERR(gss_auth->pipe[1]->dentry);
+		goto err_destroy_pipe_0;
+	}
+
+	gss_auth->pipe[0]->dentry = rpc_mkpipe_dentry(clnt->cl_path.dentry,
+						      gss_auth->mech->gm_name,
+						      clnt, gss_auth->pipe[0]);
+	if (IS_ERR(gss_auth->pipe[0]->dentry)) {
+		err = PTR_ERR(gss_auth->pipe[0]->dentry);
 		goto err_unlink_pipe_1;
 	}
 	err = rpcauth_init_credcache(auth);
@@ -822,9 +834,13 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 
 	return auth;
 err_unlink_pipe_0:
-	rpc_unlink(gss_auth->dentry[0]);
+	rpc_unlink(gss_auth->pipe[0]->dentry);
 err_unlink_pipe_1:
-	rpc_unlink(gss_auth->dentry[1]);
+	rpc_unlink(gss_auth->pipe[1]->dentry);
+err_destroy_pipe_0:
+	rpc_destroy_pipe_data(gss_auth->pipe[0]);
+err_destroy_pipe_1:
+	rpc_destroy_pipe_data(gss_auth->pipe[1]);
 err_put_mech:
 	gss_mech_put(gss_auth->mech);
 err_free:
@@ -837,8 +853,10 @@ out_dec:
 static void
 gss_free(struct gss_auth *gss_auth)
 {
-	rpc_unlink(gss_auth->dentry[1]);
-	rpc_unlink(gss_auth->dentry[0]);
+	rpc_unlink(gss_auth->pipe[0]->dentry);
+	rpc_unlink(gss_auth->pipe[1]->dentry);
+	rpc_destroy_pipe_data(gss_auth->pipe[0]);
+	rpc_destroy_pipe_data(gss_auth->pipe[1]);
 	gss_mech_put(gss_auth->mech);
 
 	kfree(gss_auth);
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 4093da79d51..6dd8b96e8df 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -206,7 +206,6 @@ static void
 rpc_i_callback(struct rcu_head *head)
 {
 	struct inode *inode = container_of(head, struct inode, i_rcu);
-	kfree(RPC_I(inode)->pipe);
 	kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 }
 
@@ -575,34 +574,44 @@ init_pipe(struct rpc_pipe *pipe)
 			    rpc_timeout_upcall_queue);
 	pipe->ops = NULL;
 	spin_lock_init(&pipe->lock);
+	pipe->dentry = NULL;
+}
 
+void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
+{
+	kfree(pipe);
 }
+EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
 
-static int __rpc_mkpipe(struct inode *dir, struct dentry *dentry,
-			umode_t mode,
-			const struct file_operations *i_fop,
-			void *private,
-			const struct rpc_pipe_ops *ops,
-			int flags)
+struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
 {
 	struct rpc_pipe *pipe;
-	struct rpc_inode *rpci;
-	int err;
 
 	pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
 	if (!pipe)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 	init_pipe(pipe);
+	pipe->ops = ops;
+	pipe->flags = flags;
+	return pipe;
+}
+EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
+
+static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
+			       umode_t mode,
+			       const struct file_operations *i_fop,
+			       void *private,
+			       struct rpc_pipe *pipe)
+{
+	struct rpc_inode *rpci;
+	int err;
+
 	err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
-	if (err) {
-		kfree(pipe);
+	if (err)
 		return err;
-	}
 	rpci = RPC_I(dentry->d_inode);
 	rpci->private = private;
 	rpci->pipe = pipe;
-	rpci->pipe->flags = flags;
-	rpci->pipe->ops = ops;
 	fsnotify_create(dir, dentry);
 	return 0;
 }
@@ -819,9 +828,8 @@ static int rpc_rmdir_depopulate(struct dentry *dentry,
  * The @private argument passed here will be available to all these methods
  * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
  */
-struct dentry *rpc_mkpipe(struct dentry *parent, const char *name,
-			  void *private, const struct rpc_pipe_ops *ops,
-			  int flags)
+struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
+				 void *private, struct rpc_pipe *pipe)
 {
 	struct dentry *dentry;
 	struct inode *dir = parent->d_inode;
@@ -829,9 +837,9 @@ struct dentry *rpc_mkpipe(struct dentry *parent, const char *name,
 	struct qstr q;
 	int err;
 
-	if (ops->upcall == NULL)
+	if (pipe->ops->upcall == NULL)
 		umode &= ~S_IRUGO;
-	if (ops->downcall == NULL)
+	if (pipe->ops->downcall == NULL)
 		umode &= ~S_IWUGO;
 
 	q.name = name;
@@ -842,8 +850,8 @@ struct dentry *rpc_mkpipe(struct dentry *parent, const char *name,
 	dentry = __rpc_lookup_create_exclusive(parent, &q);
 	if (IS_ERR(dentry))
 		goto out;
-	err = __rpc_mkpipe(dir, dentry, umode, &rpc_pipe_fops,
-			   private, ops, flags);
+	err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
+				  private, pipe);
 	if (err)
 		goto out_err;
 out:
@@ -856,7 +864,7 @@ out_err:
 			err);
 	goto out;
 }
-EXPORT_SYMBOL_GPL(rpc_mkpipe);
+EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
 
 /**
  * rpc_unlink - remove a pipe