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)) {
4668	trochtova	92	case IPC_M_PHONE_HUNGUP:
		93	return;
		94	case VFS_OUT_MOUNTED:
4419	trochtova	95	fat_mounted(callid, &call);
		96	break;
4668	trochtova	97	case VFS_OUT_MOUNT:
4419	trochtova	98	fat_mount(callid, &call);
		99	break;
4668	trochtova	100	case VFS_OUT_LOOKUP:
4419	trochtova	101	fat_lookup(callid, &call);
		102	break;
4668	trochtova	103	case VFS_OUT_READ:
4419	trochtova	104	fat_read(callid, &call);
		105	break;
4668	trochtova	106	case VFS_OUT_WRITE:
4419	trochtova	107	fat_write(callid, &call);
		108	break;
4668	trochtova	109	case VFS_OUT_TRUNCATE:
4419	trochtova	110	fat_truncate(callid, &call);
		111	break;
4668	trochtova	112	case VFS_OUT_STAT:
		113	fat_stat(callid, &call);
		114	break;
		115	case VFS_OUT_CLOSE:
4537	trochtova	116	fat_close(callid, &call);
		117	break;
4668	trochtova	118	case VFS_OUT_DESTROY:
4419	trochtova	119	fat_destroy(callid, &call);
		120	break;
4668	trochtova	121	case VFS_OUT_OPEN_NODE:
4537	trochtova	122	fat_open_node(callid, &call);
		123	break;
4668	trochtova	124	case VFS_OUT_SYNC:
4537	trochtova	125	fat_sync(callid, &call);
		126	break;
4419	trochtova	127	default:
		128	ipc_answer_0(callid, ENOTSUP);
		129	break;
		130	}
		131	}
		132	}
		133
		134	int main(int argc, char **argv)
		135	{
		136	int vfs_phone;
		137	int rc;
		138
		139	printf("fat: HelenOS FAT file system server.\n");
		140
		141	rc = fat_idx_init();
		142	if (rc != EOK)
		143	goto err;
		144
		145	vfs_phone = ipc_connect_me_to_blocking(PHONE_NS, SERVICE_VFS, 0, 0);
		146	if (vfs_phone < EOK) {
		147	printf("fat: failed to connect to VFS\n");
		148	return -1;
		149	}
		150
		151	rc = fs_register(vfs_phone, &fat_reg, &fat_vfs_info, fat_connection);
		152	if (rc != EOK) {
		153	fat_idx_fini();
		154	goto err;
		155	}
		156
		157	dprintf("FAT filesystem registered, fs_handle=%d.\n",
		158	fat_reg.fs_handle);
		159
		160	async_manager();
		161	/* not reached */
		162	return 0;
		163
		164	err:
		165	printf("Failed to register the FAT file system (%d)\n", rc);
		166	return rc;
		167	}
		168
		169	/**
		170	* @}
		171	*/

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