WebSVN – HelenOS – Blame – /branches/dd/uspace/srv/fs/fat/fat.c

Rev	Author	Line No.	Line
4419	trochtova	1	/*
		2	* Copyright (c) 2006 Martin Decky
		3	* Copyright (c) 2008 Jakub Jermar
		4	* All rights reserved.
		5	*
		6	* Redistribution and use in source and binary forms, with or without
		7	* modification, are permitted provided that the following conditions
		8	* are met:
		9	*
		10	* - Redistributions of source code must retain the above copyright
		11	* notice, this list of conditions and the following disclaimer.
		12	* - Redistributions in binary form must reproduce the above copyright
		13	* notice, this list of conditions and the following disclaimer in the
		14	* documentation and/or other materials provided with the distribution.
		15	* - The name of the author may not be used to endorse or promote products
		16	* derived from this software without specific prior written permission.
		17	*
		18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		28	*/
		29
		30	/** @addtogroup fs
		31	* @{
		32	*/
		33
		34	/**
		35	* @file fat.c
		36	* @brief FAT file system driver for HelenOS.
		37	*/
		38
		39	#include "fat.h"
		40	#include <ipc/ipc.h>
		41	#include <ipc/services.h>
		42	#include <async.h>
		43	#include <errno.h>
		44	#include <unistd.h>
		45	#include <stdio.h>
		46	#include <libfs.h>
		47	#include "../../vfs/vfs.h"
		48
		49
		50	vfs_info_t fat_vfs_info = {
		51	.name = "fat",
		52	};
		53
		54	fs_reg_t fat_reg;
		55
		56	/**
		57	* This connection fibril processes VFS requests from VFS.
		58	*
		59	* In order to support simultaneous VFS requests, our design is as follows.
		60	* The connection fibril accepts VFS requests from VFS. If there is only one
		61	* instance of the fibril, VFS will need to serialize all VFS requests it sends
		62	* to FAT. To overcome this bottleneck, VFS can send FAT the IPC_M_CONNECT_ME_TO
		63	* call. In that case, a new connection fibril will be created, which in turn
		64	* will accept the call. Thus, a new phone will be opened for VFS.
		65	*
		66	* There are few issues with this arrangement. First, VFS can run out of
		67	* available phones. In that case, VFS can close some other phones or use one
		68	* phone for more serialized requests. Similarily, FAT can refuse to duplicate
		69	* the connection. VFS should then just make use of already existing phones and
		70	* route its requests through them. To avoid paying the fibril creation price
		71	* upon each request, FAT might want to keep the connections open after the
		72	* request has been completed.
		73	*/
		74	static void fat_connection(ipc_callid_t iid, ipc_call_t *icall)
		75	{
		76	if (iid) {
		77	/*
		78	* This only happens for connections opened by
		79	* IPC_M_CONNECT_ME_TO calls as opposed to callback connections
		80	* created by IPC_M_CONNECT_TO_ME.
		81	*/
		82	ipc_answer_0(iid, EOK);
		83	}
		84
		85	dprintf("VFS-FAT connection established.\n");
		86	while (1) {
		87	ipc_callid_t callid;
		88	ipc_call_t call;
		89
		90	callid = async_get_call(&call);
		91	switch (IPC_GET_METHOD(call)) {
		92	case VFS_MOUNTED:
		93	fat_mounted(callid, &call);
		94	break;
		95	case VFS_MOUNT:
		96	fat_mount(callid, &call);
		97	break;
		98	case VFS_LOOKUP:
		99	fat_lookup(callid, &call);
		100	break;
		101	case VFS_READ:
		102	fat_read(callid, &call);
		103	break;
		104	case VFS_WRITE:
		105	fat_write(callid, &call);
		106	break;
		107	case VFS_TRUNCATE:
		108	fat_truncate(callid, &call);
		109	break;
4537	trochtova	110	case VFS_CLOSE:
		111	fat_close(callid, &call);
		112	break;
4419	trochtova	113	case VFS_DESTROY:
		114	fat_destroy(callid, &call);
		115	break;
4537	trochtova	116	case VFS_OPEN_NODE:
		117	fat_open_node(callid, &call);
		118	break;
		119	case VFS_DEVICE:
		120	fat_device(callid, &call);
		121	break;
		122	case VFS_SYNC:
		123	fat_sync(callid, &call);
		124	break;
4419	trochtova	125	default:
		126	ipc_answer_0(callid, ENOTSUP);
		127	break;
		128	}
		129	}
		130	}
		131
		132	int main(int argc, char **argv)
		133	{
		134	int vfs_phone;
		135	int rc;
		136
		137	printf("fat: HelenOS FAT file system server.\n");
		138
		139	rc = fat_idx_init();
		140	if (rc != EOK)
		141	goto err;
		142
		143	vfs_phone = ipc_connect_me_to_blocking(PHONE_NS, SERVICE_VFS, 0, 0);
		144	if (vfs_phone < EOK) {
		145	printf("fat: failed to connect to VFS\n");
		146	return -1;
		147	}
		148
		149	rc = fs_register(vfs_phone, &fat_reg, &fat_vfs_info, fat_connection);
		150	if (rc != EOK) {
		151	fat_idx_fini();
		152	goto err;
		153	}
		154
		155	dprintf("FAT filesystem registered, fs_handle=%d.\n",
		156	fat_reg.fs_handle);
		157
		158	async_manager();
		159	/* not reached */
		160	return 0;
		161
		162	err:
		163	printf("Failed to register the FAT file system (%d)\n", rc);
		164	return rc;
		165	}
		166
		167	/**
		168	* @}
		169	*/

Subversion Repositories HelenOS

(root)/branches/dd/uspace/srv/fs/fat/fat.c – Rev 4537