Subversion Repositories HelenOS

/*

 * Copyright (c) 2008 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/** @addtogroup fs

 * @{

 */

/**

 * @file vfs.c

 * @brief VFS service for HelenOS.

 */

#include <ipc/ipc.h>

#include <ipc/services.h>

#include <async.h>

#include <errno.h>

#include <stdio.h>

#include <bool.h>

#include <string.h>

#include <as.h>

#include <libadt/list.h>

#include <atomic.h>

#include "vfs.h"

#define NAME "vfs"

static void vfs_connection(ipc_callid_t iid, ipc_call_t *icall)

{

	bool keep_on_going = true;

	/*

	 * The connection was opened via the IPC_CONNECT_ME_TO call.

	 * This call needs to be answered.

	 */

	ipc_answer_0(iid, EOK);

	/*

	 * Here we enter the main connection fibril loop.

	 * The logic behind this loop and the protocol is that we'd like to keep

	 * each connection open until the client hangs up. When the client hangs

	 * up, we will free its VFS state. The act of hanging up the connection

	 * by the client is equivalent to client termination because we cannot

	 * distinguish one from the other. On the other hand, the client can

	 * hang up arbitrarily if it has no open files and reestablish the

	 * connection later.

	 */

	while (keep_on_going) {

		ipc_call_t call;

		ipc_callid_t callid = async_get_call(&call);

		fs_handle_t fs_handle;

		int phone;

		switch (IPC_GET_METHOD(call)) {

		case IPC_M_PHONE_HUNGUP:

			keep_on_going = false;

			break;

		case IPC_M_CONNECT_ME_TO:

			/*

			 * Connect the client file system to another one.

			 */

			/* FIXME:

			 * Prevent ordinary clients from connecting to file

			 * system servers directly. This should be solved by

			 * applying some security mechanisms.

			 */

			fs_handle = IPC_GET_ARG1(call);

			phone = vfs_grab_phone(fs_handle);

			(void) ipc_forward_fast(callid, phone, 0, 0, 0,

			    IPC_FF_NONE);

			vfs_release_phone(phone);

			break;

		case VFS_REGISTER:

			vfs_register(callid, &call);

			/*

			 * Keep the connection open so that a file system can

			 * later ask us to connect it to another file system.

			 * This is necessary to support non-root mounts.

			 */

			break;

		case VFS_MOUNT:

			vfs_mount(callid, &call);

			break;

		case VFS_OPEN:

			vfs_open(callid, &call);

			break;

		case VFS_CLOSE:

			vfs_close(callid, &call);

			break;

		case VFS_READ:

			vfs_read(callid, &call);

			break;

		case VFS_WRITE:

			vfs_write(callid, &call);

			break;

		case VFS_SEEK:

			vfs_seek(callid, &call);

			break;

		case VFS_TRUNCATE:

			vfs_truncate(callid, &call);

			break;

		case VFS_MKDIR:

			vfs_mkdir(callid, &call);

			break;

		case VFS_UNLINK:

			vfs_unlink(callid, &call);

			break;

		case VFS_RENAME:

			vfs_rename(callid, &call);

			break;

		default:

			ipc_answer_0(callid, ENOTSUP);

			break;

		}

	}

	/* TODO: cleanup after the client */

}

int main(int argc, char **argv)

{

	printf(NAME ": HelenOS VFS server\n");

	/*

	 * Initialize the list of registered file systems.

	 */

	list_initialize(&fs_head);

	/*

	 * Initialize VFS node hash table.

	 */

	if (!vfs_nodes_init()) {

		printf(NAME ": Failed to initialize VFS node hash table\n");

		return ENOMEM;

	}

	/*

	 * Allocate and initialize the Path Lookup Buffer.

	 */

	list_initialize(&plb_head);

	plb = as_get_mappable_page(PLB_SIZE);

	if (!plb) {

		printf(NAME ": Cannot allocate a mappable piece of address space\n");

		return ENOMEM;

	}

	if (as_area_create(plb, PLB_SIZE, AS_AREA_READ | AS_AREA_WRITE |

	    AS_AREA_CACHEABLE) != plb) {

		printf(NAME ": Cannot create address space area\n");

		return ENOMEM;

	}

	memset(plb, 0, PLB_SIZE);

	/*

	 * Set a connectio handling function/fibril.

	 */

	async_set_client_connection(vfs_connection);

	/*

	 * Register at the naming service.

	 */

	ipcarg_t phonead;

	ipc_connect_to_me(PHONE_NS, SERVICE_VFS, 0, 0, &phonead);

	/*

	 * Start accepting connections.

	 */

	printf(NAME ": Accepting connections\n");

	async_manager();

	return 0;

}

/**

 * @}

 */