WebSVN – HelenOS – Diff – /trunk/uspace/srv/fs/fat/fat.c


/*
 * Copyright (c) 2006 Martin Decky
 * Copyright (c) 2007 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    fat.c
 * @brief   FAT file system driver for HelenOS.
 */
 
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <async.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <as.h>
#include "../../vfs/vfs.h"
 
#define dprintf(...)    printf(__VA_ARGS__)
 
vfs_info_t fat_vfs_info = {
    .name = "fat",
    .ops = {
        [IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_OPEN)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_CREATE)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_NULL,
        [IPC_METHOD_TO_VFS_OP(VFS_SEEK)] = VFS_OP_DEFAULT
    }
};
 
uint8_t *plb_ro = NULL;
 
int fs_handle = 0;
 
/**
 * This connection fibril processes VFS requests from VFS.
 *
 * In order to support simultaneous VFS requests, our design is as follows.
 * The connection fibril accepts VFS requests from VFS. If there is only one
 * instance of the fibril, VFS will need to serialize all VFS requests it sends
 * to FAT. To overcome this bottleneck, VFS can send FAT the IPC_M_CONNECT_ME_TO
 * call. In that case, a new connection fibril will be created, which in turn
 * will accept the call. Thus, a new phone will be opened for VFS.
 *
 * There are few issues with this arrangement. First, VFS can run out of
 * available phones. In that case, VFS can close some other phones or use one
 * phone for more serialized requests. Similarly, FAT can refuse to duplicate
 * the connection. VFS should then just make use of already existing phones and
 * route its requests through them. To avoid paying the fibril creation price
 * upon each request, FAT might want to keep the connections open after the
 * request has been completed.
 */
static void fat_connection(ipc_callid_t iid, ipc_call_t *icall)
{
    if (iid) {
        /*
         * This only happens for connections opened by
         * IPC_M_CONNECT_ME_TO calls as opposed to callback connections
         * created by IPC_M_CONNECT_TO_ME.
         */
        ipc_answer_fast(iid, EOK, 0, 0);
    }
   
    dprintf("VFS-FAT connection established.\n");
    while (1) {
        ipc_callid_t callid;
        ipc_call_t call;
   
        callid = async_get_call(&call);
        switch  (IPC_GET_METHOD(call)) {
        default:
            ipc_answer_fast(callid, ENOTSUP, 0, 0);
            break;
        }
    }
}
 
int main(int argc, char **argv)
{
    int vfs_phone;
 
    printf("FAT: HelenOS FAT file system server.\n");
 
    vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0);
    while (vfs_phone < EOK) {
        usleep(10000);
        vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0);
    }
   
    /*
     * Tell VFS that we are here and want to get registered.
     * We use the async framework because VFS will answer the request
     * out-of-order, when it knows that the operation succeeded or failed.
     */
    ipc_call_t answer;
    aid_t req = async_send_2(vfs_phone, VFS_REGISTER, 0, 0, &answer);
 
    /*
     * Send our VFS info structure to VFS.
     */
    int rc = ipc_data_send(vfs_phone, &fat_vfs_info, sizeof(fat_vfs_info));
    if (rc != EOK) {
        async_wait_for(req, NULL);
        return rc;
    }
 
    /*
     * Ask VFS for callback connection.
     */
    ipcarg_t phonehash;
    ipc_connect_to_me(vfs_phone, 0, 0, &phonehash);
 
    /*
     * Allocate piece of address space for PLB.
     */
    plb_ro = as_get_mappable_page(PLB_SIZE);
    if (!plb_ro) {
        async_wait_for(req, NULL);
        return ENOMEM;
    }
 
    /*
     * Request sharing the Path Lookup Buffer with VFS.
     */
    rc = ipc_call_sync_3(vfs_phone, IPC_M_AS_AREA_RECV, (ipcarg_t) plb_ro,
        PLB_SIZE, 0, NULL, NULL, NULL);
    if (rc) {
        async_wait_for(req, NULL);
        return rc;
    }
     
    /*
     * Pick up the answer for the request to the VFS_REQUEST call.
     */
    async_wait_for(req, NULL);
    fs_handle = (int) IPC_GET_ARG1(answer);
    dprintf("FAT filesystem registered, fs_handle=%d.\n", fs_handle);
 
    /*
     * Create a connection fibril to handle the callback connection.
     */
    async_new_connection(phonehash, 0, NULL, fat_connection);
   
    /*
     * Tell the async framework that other connections are to be handled by
     * the same connection fibril as well.
     */
    async_set_client_connection(fat_connection);
 
 
 
 
 
 
 
    async_create_manager();
 
    /*
     * TODO: Interestingly, if we merely return, the only thread dies.
     *   If the only thread dies, the whole task is destroyed.
     *   Prevent the thread from exiting when there are active fibrils.
     */
    fibril_schedule_next_adv(FIBRIL_FROM_DEAD);
    /* not reached */
 
    return 0;
}
 
/**
 * @}
 */
 

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat.c @ 4718 – Rev 2543 → 2546

Rev 2543		Rev 2546
1	/*	1	/*
2	* Copyright (c) 2006 Martin Decky	2	* Copyright (c) 2006 Martin Decky
3	* Copyright (c) 2007 Jakub Jermar	3	* Copyright (c) 2007 Jakub Jermar
4	* All rights reserved.	4	* All rights reserved.
5	*	5	*
6	* Redistribution and use in source and binary forms, with or without	6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions	7	* modification, are permitted provided that the following conditions
8	* are met:	8	* are met:
9	*	9	*
10	* - Redistributions of source code must retain the above copyright	10	* - Redistributions of source code must retain the above copyright
11	* notice, this list of conditions and the following disclaimer.	11	* notice, this list of conditions and the following disclaimer.
12	* - Redistributions in binary form must reproduce the above copyright	12	* - Redistributions in binary form must reproduce the above copyright
13	* notice, this list of conditions and the following disclaimer in the	13	* notice, this list of conditions and the following disclaimer in the
14	* documentation and/or other materials provided with the distribution.	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	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.	16	* derived from this software without specific prior written permission.
17	*	17	*
18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	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	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	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	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	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	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.	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28	*/	28	*/
29		29
30	/** @addtogroup fs	30	/** @addtogroup fs
31	* @{	31	* @{
32	*/	32	*/
33		33
34	/**	34	/**
35	* @file fat.c	35	* @file fat.c
36	* @brief FAT file system driver for HelenOS.	36	* @brief FAT file system driver for HelenOS.
37	*/	37	*/
38		38
39	#include <ipc/ipc.h>	39	#include <ipc/ipc.h>
40	#include <ipc/services.h>	40	#include <ipc/services.h>
41	#include <async.h>	41	#include <async.h>
42	#include <errno.h>	42	#include <errno.h>
43	#include <unistd.h>	43	#include <unistd.h>
44	#include <stdio.h>	44	#include <stdio.h>
45	#include <as.h>>	45	#include <as.h>
46	#include "../../vfs/vfs.h"	46	#include "../../vfs/vfs.h"
47		47
48	#define dprintf(...) printf(__VA_ARGS__)	48	#define dprintf(...) printf(__VA_ARGS__)
49		49
50	vfs_info_t fat_vfs_info = {	50	vfs_info_t fat_vfs_info = {
51	.name = "fat",	51	.name = "fat",
52	.ops = {	52	.ops = {
53	[IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] = VFS_OP_DEFINED,	53	[IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] = VFS_OP_DEFINED,
54	[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_DEFINED,	54	[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_DEFINED,
55	[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_DEFINED,	55	[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_DEFINED,
56	[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED,	56	[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED,
57	[IPC_METHOD_TO_VFS_OP(VFS_OPEN)] = VFS_OP_DEFINED,	57	[IPC_METHOD_TO_VFS_OP(VFS_OPEN)] = VFS_OP_DEFINED,
58	[IPC_METHOD_TO_VFS_OP(VFS_CREATE)] = VFS_OP_DEFINED,	58	[IPC_METHOD_TO_VFS_OP(VFS_CREATE)] = VFS_OP_DEFINED,
59	[IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] = VFS_OP_DEFINED,	59	[IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] = VFS_OP_DEFINED,
60	[IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED,	60	[IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED,
61	[IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_NULL,	61	[IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_NULL,
62	[IPC_METHOD_TO_VFS_OP(VFS_SEEK)] = VFS_OP_DEFAULT	62	[IPC_METHOD_TO_VFS_OP(VFS_SEEK)] = VFS_OP_DEFAULT
63	}	63	}
64	};	64	};
65		65
66	uint8_t *plb_ro = NULL;	66	uint8_t *plb_ro = NULL;
67		67
-		68	int fs_handle = 0;
-		69
68	/**	70	/**
69	* This connection fibril processes VFS requests from VFS.	71	* This connection fibril processes VFS requests from VFS.
70	*	72	*
71	* In order to support simultaneous VFS requests, our design is as follows.	73	* In order to support simultaneous VFS requests, our design is as follows.
72	* The connection fibril accepts VFS requests from VFS. If there is only one	74	* The connection fibril accepts VFS requests from VFS. If there is only one
73	* instance of the fibril, VFS will need to serialize all VFS requests it sends	75	* instance of the fibril, VFS will need to serialize all VFS requests it sends
74	* to FAT. To overcome this bottleneck, VFS can send FAT the IPC_M_CONNECT_ME_TO	76	* to FAT. To overcome this bottleneck, VFS can send FAT the IPC_M_CONNECT_ME_TO
75	* call. In that case, a new connection fibril will be created, which in turn	77	* call. In that case, a new connection fibril will be created, which in turn
76	* will accept the call. Thus, a new phone will be opened for VFS.	78	* will accept the call. Thus, a new phone will be opened for VFS.
77	*	79	*
78	* There are few issues with this arrangement. First, VFS can run out of	80	* There are few issues with this arrangement. First, VFS can run out of
79	* available phones. In that case, VFS can close some other phones or use one	81	* available phones. In that case, VFS can close some other phones or use one
80	* phone for more serialized requests. Similarly, FAT can refuse to duplicate	82	* phone for more serialized requests. Similarly, FAT can refuse to duplicate
81	* the connection. VFS should then just make use of already existing phones and	83	* the connection. VFS should then just make use of already existing phones and
82	* route its requests through them. To avoid paying the fibril creation price	84	* route its requests through them. To avoid paying the fibril creation price
83	* upon each request, FAT might want to keep the connections open after the	85	* upon each request, FAT might want to keep the connections open after the
84	* request has been completed.	86	* request has been completed.
85	*/	87	*/
86	static void fat_connection(ipc_callid_t iid, ipc_call_t *icall)	88	static void fat_connection(ipc_callid_t iid, ipc_call_t *icall)
87	{	89	{
88	if (iid) {	90	if (iid) {
89	/*	91	/*
90	* This only happens for connections opened by	92	* This only happens for connections opened by
91	* IPC_M_CONNECT_ME_TO calls as opposed to callback connections	93	* IPC_M_CONNECT_ME_TO calls as opposed to callback connections
92	* created by IPC_M_CONNECT_TO_ME.	94	* created by IPC_M_CONNECT_TO_ME.
93	*/	95	*/
94	ipc_answer_fast(iid, EOK, 0, 0);	96	ipc_answer_fast(iid, EOK, 0, 0);
95	}	97	}
96		98
97	dprintf("VFS-FAT connection established.\n");	99	dprintf("VFS-FAT connection established.\n");
98	while (1) {	100	while (1) {
99	ipc_callid_t callid;	101	ipc_callid_t callid;
100	ipc_call_t call;	102	ipc_call_t call;
101		103
102	callid = async_get_call(&call);	104	callid = async_get_call(&call);
103	switch (IPC_GET_METHOD(call)) {	105	switch (IPC_GET_METHOD(call)) {
104	default:	106	default:
105	ipc_answer_fast(callid, ENOTSUP, 0, 0);	107	ipc_answer_fast(callid, ENOTSUP, 0, 0);
106	break;	108	break;
107	}	109	}
108	}	110	}
109	}	111	}
110		112
111	int main(int argc, char **argv)	113	int main(int argc, char **argv)
112	{	114	{
113	int vfs_phone;	115	int vfs_phone;
114		116
115	printf("FAT: HelenOS FAT file system server.\n");	117	printf("FAT: HelenOS FAT file system server.\n");
116		118
117	vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0);	119	vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0);
118	while (vfs_phone < EOK) {	120	while (vfs_phone < EOK) {
119	usleep(10000);	121	usleep(10000);
120	vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0);	122	vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0);
121	}	123	}
122		124
123	/*	125	/*
124	* Tell VFS that we are here and want to get registered.	126	* Tell VFS that we are here and want to get registered.
125	* We use the async framework because VFS will answer the request	127	* We use the async framework because VFS will answer the request
126	* out-of-order, when it knows that the operation succeeded or failed.	128	* out-of-order, when it knows that the operation succeeded or failed.
127	*/	129	*/
128	ipc_call_t answer;	130	ipc_call_t answer;
129	aid_t req = async_send_2(vfs_phone, VFS_REGISTER, 0, 0, &answer);	131	aid_t req = async_send_2(vfs_phone, VFS_REGISTER, 0, 0, &answer);
130		132
131	/*	133	/*
132	* Send our VFS info structure to VFS.	134	* Send our VFS info structure to VFS.
133	*/	135	*/
134	int rc = ipc_data_send(vfs_phone, &fat_vfs_info, sizeof(fat_vfs_info));	136	int rc = ipc_data_send(vfs_phone, &fat_vfs_info, sizeof(fat_vfs_info));
135	if (rc != EOK) {	137	if (rc != EOK) {
136	async_wait_for(req, NULL);	138	async_wait_for(req, NULL);
137	return rc;	139	return rc;
138	}	140	}
139		141
140	/*	142	/*
141	* Ask VFS for callback connection.	143	* Ask VFS for callback connection.
142	*/	144	*/
143	ipcarg_t phonehash;	145	ipcarg_t phonehash;
144	ipc_connect_to_me(vfs_phone, 0, 0, &phonehash);	146	ipc_connect_to_me(vfs_phone, 0, 0, &phonehash);
145		147
146	/*	148	/*
147	* Allocate piece of address space for PLB.	149	* Allocate piece of address space for PLB.
148	*/	150	*/
149	plb_ro = as_get_mappable_page(PLB_SIZE);	151	plb_ro = as_get_mappable_page(PLB_SIZE);
150	if (!plb_ro) {	152	if (!plb_ro) {
151	async_wait_for(req, NULL);	153	async_wait_for(req, NULL);
152	return ENOMEM;	154	return ENOMEM;
153	}	155	}
154		156
155	/*	157	/*
156	* Request sharing the Path Lookup Buffer with VFS.	158	* Request sharing the Path Lookup Buffer with VFS.
157	*/	159	*/
158	rc = ipc_call_sync_3(vfs_phone, IPC_M_AS_AREA_RECV, plb_ro, PLB_SIZE, 0,	160	rc = ipc_call_sync_3(vfs_phone, IPC_M_AS_AREA_RECV, (ipcarg_t) plb_ro,
159	NULL, NULL, NULL);	161	PLB_SIZE, 0, NULL, NULL, NULL);
160	if (rc) {	162	if (rc) {
161	async_wait_for(req, NULL);	163	async_wait_for(req, NULL);
162	return rc;	164	return rc;
163	}	165	}
164		166
165	/*	167	/*
-		168	* Pick up the answer for the request to the VFS_REQUEST call.
-		169	*/
-		170	async_wait_for(req, NULL);
-		171	fs_handle = (int) IPC_GET_ARG1(answer);
-		172	dprintf("FAT filesystem registered, fs_handle=%d.\n", fs_handle);
-		173
-		174	/*
166	* Create a connection fibril to handle the callback connection.	175	* Create a connection fibril to handle the callback connection.
167	*/	176	*/
168	async_new_connection(phonehash, 0, NULL, fat_connection);	177	async_new_connection(phonehash, 0, NULL, fat_connection);
169		178
170	/*	179	/*
171	* Tell the async framework that other connections are to be handled by	180	* Tell the async framework that other connections are to be handled by
172	* the same connection fibril as well.	181	* the same connection fibril as well.
173	*/	182	*/
174	async_set_client_connection(fat_connection);	183	async_set_client_connection(fat_connection);
175		184
176	/*	-
177	* Pick up the answer for the request to the VFS_REQUEST call.	-
178	*/	-
179	async_wait_for(req, NULL);	-
180	dprintf("FAT filesystem registered.\n");	-
181		-
182	async_create_manager();	185	async_create_manager();
183		186
184	/*	187	/*
185	* TODO: Interestingly, if we merely return, the only thread dies.	188	* TODO: Interestingly, if we merely return, the only thread dies.
186	* If the only thread dies, the whole task is destroyed.	189	* If the only thread dies, the whole task is destroyed.
187	* Prevent the thread from exiting when there are active fibrils.	190	* Prevent the thread from exiting when there are active fibrils.
188	*/	191	*/
189	fibril_schedule_next_adv(FIBRIL_FROM_DEAD);	192	fibril_schedule_next_adv(FIBRIL_FROM_DEAD);
190	/* not reached */	193	/* not reached */
191		194
192	return 0;	195	return 0;
193	}	196	}
194		197
195	/**	198	/**
196	* @}	199	* @}
197	*/	200	*/
198		201