sunrpc: document the rpc_pipefs kernel api (93a44a75) · Commits · e / devices / android_kernel_fairphone_FP5

net/sunrpc/rpc_pipe.c

+51 −1

Original line number	Diff line number	Diff line
		@@ -76,6 +76,16 @@ rpc_timeout_upcall_queue(struct work_struct *work)
		rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
		}

		/**
		* rpc_queue_upcall
		* @inode: inode of upcall pipe on which to queue given message
		* @msg: message to queue
		*
		* Call with an @inode created by rpc_mkpipe() to queue an upcall.
		* A userspace process may then later read the upcall by performing a
		* read on an open file for this inode. It is up to the caller to
		* initialize the fields of @msg (other than @msg->list) appropriately.
		*/
		int
		rpc_queue_upcall(struct inode inode, struct rpc_pipe_msg msg)
		{
		@@ -663,7 +673,16 @@ rpc_lookup_negative(char path, struct nameidata nd)
		return dentry;
		}


		/**
		* rpc_mkdir - Create a new directory in rpc_pipefs
		* @path: path from the rpc_pipefs root to the new directory
		* @rpc_clnt: rpc client to associate with this directory
		*
		* This creates a directory at the given @path associated with
		* @rpc_clnt, which will contain a file named "info" with some basic
		* information about the client, together with any "pipes" that may
		* later be created using rpc_mkpipe().
		*/
		struct dentry *
		rpc_mkdir(char path, struct rpc_clnt rpc_client)
		{
		@@ -699,6 +718,10 @@ rpc_mkdir(char path, struct rpc_clnt rpc_client)
		goto out;
		}

		/**
		* rpc_rmdir - Remove a directory created with rpc_mkdir()
		* @dentry: directory to remove
		*/
		int
		rpc_rmdir(struct dentry *dentry)
		{
		@@ -717,6 +740,25 @@ rpc_rmdir(struct dentry *dentry)
		return error;
		}

		/**
		* rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
		* @parent: dentry of directory to create new "pipe" in
		* @name: name of pipe
		* @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, and destroy_msg.
		*
		* Data is made available for userspace to read by calls to
		* rpc_queue_upcall(). The actual reads will result in calls to
		* @ops->upcall, which will be called with the file pointer,
		* message, and userspace buffer to copy to.
		*
		* Writes can come at any time, and do not necessarily have to be
		* responses to upcalls. They will result in calls to @msg->downcall.
		*
		* 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, struct rpc_pipe_ops ops, int flags)
		{
		@@ -764,6 +806,14 @@ rpc_mkpipe(struct dentry parent, const char name, void *private, struct rpc_pi
		goto out;
		}

		/**
		* rpc_unlink - remove a pipe
		* @dentry: dentry for the pipe, as returned from rpc_mkpipe
		*
		* After this call, lookups will no longer find the pipe, and any
		* attempts to read or write using preexisting opens of the pipe will
		* return -EPIPE.
		*/
		int
		rpc_unlink(struct dentry *dentry)
		{