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


/*
 * Copyright (c) 2006 Martin Decky
 * 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    tmpfs.c
 * @brief   File system driver for in-memory file system.
 *
 * Every instance of tmpfs exists purely in memory and has neither a disk layout
 * nor any permanent storage (e.g. disk blocks). With each system reboot, data
 * stored in a tmpfs file system is lost.
 */
 
#include "tmpfs.h"
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <async.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <libfs.h>
#include "../../vfs/vfs.h"
 
 
vfs_info_t tmpfs_vfs_info = {
    .name = "tmpfs",
    .ops = {
        [IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_TRUNCATE)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_DEFINED,
        [IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_NULL,
        [IPC_METHOD_TO_VFS_OP(VFS_DESTROY)] = VFS_OP_DEFINED,
    }
};
 
fs_reg_t tmpfs_reg;
 
/**
 * 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 TMPFS 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. Similarily, TMPFS 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, TMPFS might want to keep the connections open after the
 * request has been completed.
 */
static void tmpfs_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_0(iid, EOK);
    }
   
    dprintf("VFS-TMPFS connection established.\n");
    while (1) {
        ipc_callid_t callid;
        ipc_call_t call;
   
        callid = async_get_call(&call);
        switch  (IPC_GET_METHOD(call)) {
        case VFS_MOUNT:
            tmpfs_mount(callid, &call);
            break;
        case VFS_LOOKUP:
            tmpfs_lookup(callid, &call);
            break;
        case VFS_READ:
            tmpfs_read(callid, &call);
            break;
        case VFS_WRITE:
            tmpfs_write(callid, &call);
            break;
        case VFS_TRUNCATE:
            tmpfs_truncate(callid, &call);
            break;
        case VFS_DESTROY:
            tmpfs_destroy(callid, &call);
            break;
        default:
            ipc_answer_0(callid, ENOTSUP);
            break;
        }
    }
}
 
int main(int argc, char **argv)
{
    int vfs_phone;
 
    printf("TMPFS: HelenOS TMPFS file system server.\n");
 
    vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);
    while (vfs_phone < EOK) {
        usleep(10000);
        vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);
    }
   
    int rc;
    rc = fs_register(vfs_phone, &tmpfs_reg, &tmpfs_vfs_info,
        tmpfs_connection);
    if (rc != EOK) {
        printf("Failed to register the TMPFS file system (%d)\n", rc);
        return rc;
    }
   
    dprintf("TMPFS filesystem registered, fs_handle=%d.\n",
        tmpfs_reg.fs_handle);
 
    async_manager();
    /* not reached */
    return 0;
}
 
/**
 * @}
 */
 

Rev 2742	Rev 2958
1	/*	1	/*
2	* Copyright (c) 2006 Martin Decky	2	* Copyright (c) 2006 Martin Decky
3	* Copyright (c) 2008 Jakub Jermar	3	* Copyright (c) 2008 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 tmpfs.c	35	* @file tmpfs.c
36	* @brief File system driver for in-memory file system.	36	* @brief File system driver for in-memory file system.
37	*	37	*
38	* Every instance of tmpfs exists purely in memory and has neither a disk layout	38	* Every instance of tmpfs exists purely in memory and has neither a disk layout
39	* nor any permanent storage (e.g. disk blocks). With each system reboot, data	39	* nor any permanent storage (e.g. disk blocks). With each system reboot, data
40	* stored in a tmpfs file system is lost.	40	* stored in a tmpfs file system is lost.
41	*/	41	*/
42		42
43	#include "tmpfs.h"	43	#include "tmpfs.h"
44	#include <ipc/ipc.h>	44	#include <ipc/ipc.h>
45	#include <ipc/services.h>	45	#include <ipc/services.h>
46	#include <async.h>	46	#include <async.h>
47	#include <errno.h>	47	#include <errno.h>
48	#include <unistd.h>	48	#include <unistd.h>
49	#include <stdio.h>	49	#include <stdio.h>
50	#include <libfs.h>	50	#include <libfs.h>
51	#include "../../vfs/vfs.h"	51	#include "../../vfs/vfs.h"
52		52
53		53
54	vfs_info_t tmpfs_vfs_info = {	54	vfs_info_t tmpfs_vfs_info = {
55	.name = "tmpfs",	55	.name = "tmpfs",
56	.ops = {	56	.ops = {
57	[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED,	57	[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED,
58	[IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED,	58	[IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED,
59	[IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_DEFINED,	59	[IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_DEFINED,
60	[IPC_METHOD_TO_VFS_OP(VFS_TRUNCATE)] = VFS_OP_DEFINED,	60	[IPC_METHOD_TO_VFS_OP(VFS_TRUNCATE)] = VFS_OP_DEFINED,
61	[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_NULL,	61	[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_DEFINED,
62	[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_NULL,	62	[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_NULL,
63	[IPC_METHOD_TO_VFS_OP(VFS_DESTROY)] = VFS_OP_DEFINED,	63	[IPC_METHOD_TO_VFS_OP(VFS_DESTROY)] = VFS_OP_DEFINED,
64	}	64	}
65	};	65	};
66		66
67	fs_reg_t tmpfs_reg;	67	fs_reg_t tmpfs_reg;
68		68
69	/**	69	/**
70	* This connection fibril processes VFS requests from VFS.	70	* This connection fibril processes VFS requests from VFS.
71	*	71	*
72	* In order to support simultaneous VFS requests, our design is as follows.	72	* In order to support simultaneous VFS requests, our design is as follows.
73	* The connection fibril accepts VFS requests from VFS. If there is only one	73	* The connection fibril accepts VFS requests from VFS. If there is only one
74	* instance of the fibril, VFS will need to serialize all VFS requests it sends	74	* instance of the fibril, VFS will need to serialize all VFS requests it sends
75	* to FAT. To overcome this bottleneck, VFS can send TMPFS the	75	* to FAT. To overcome this bottleneck, VFS can send TMPFS the
76	* IPC_M_CONNECT_ME_TO call. In that case, a new connection fibril will be	76	* IPC_M_CONNECT_ME_TO call. In that case, a new connection fibril will be
77	* created, which in turn will accept the call. Thus, a new phone will be	77	* created, which in turn will accept the call. Thus, a new phone will be
78	* opened for VFS.	78	* opened for VFS.
79	*	79	*
80	* 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
81	* 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
82	* phone for more serialized requests. Similarily, TMPFS can refuse to duplicate	82	* phone for more serialized requests. Similarily, TMPFS can refuse to duplicate
83	* 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
84	* 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
85	* upon each request, TMPFS might want to keep the connections open after the	85	* upon each request, TMPFS might want to keep the connections open after the
86	* request has been completed.	86	* request has been completed.
87	*/	87	*/
88	static void tmpfs_connection(ipc_callid_t iid, ipc_call_t *icall)	88	static void tmpfs_connection(ipc_callid_t iid, ipc_call_t *icall)
89	{	89	{
90	if (iid) {	90	if (iid) {
91	/*	91	/*
92	* This only happens for connections opened by	92	* This only happens for connections opened by
93	* IPC_M_CONNECT_ME_TO calls as opposed to callback connections	93	* IPC_M_CONNECT_ME_TO calls as opposed to callback connections
94	* created by IPC_M_CONNECT_TO_ME.	94	* created by IPC_M_CONNECT_TO_ME.
95	*/	95	*/
96	ipc_answer_0(iid, EOK);	96	ipc_answer_0(iid, EOK);
97	}	97	}
98		98
99	dprintf("VFS-TMPFS connection established.\n");	99	dprintf("VFS-TMPFS connection established.\n");
100	while (1) {	100	while (1) {
101	ipc_callid_t callid;	101	ipc_callid_t callid;
102	ipc_call_t call;	102	ipc_call_t call;
103		103
104	callid = async_get_call(&call);	104	callid = async_get_call(&call);
105	switch (IPC_GET_METHOD(call)) {	105	switch (IPC_GET_METHOD(call)) {
-		106	case VFS_MOUNT:
-		107	tmpfs_mount(callid, &call);
-		108	break;
106	case VFS_LOOKUP:	109	case VFS_LOOKUP:
107	tmpfs_lookup(callid, &call);	110	tmpfs_lookup(callid, &call);
108	break;	111	break;
109	case VFS_READ:	112	case VFS_READ:
110	tmpfs_read(callid, &call);	113	tmpfs_read(callid, &call);
111	break;	114	break;
112	case VFS_WRITE:	115	case VFS_WRITE:
113	tmpfs_write(callid, &call);	116	tmpfs_write(callid, &call);
114	break;	117	break;
115	case VFS_TRUNCATE:	118	case VFS_TRUNCATE:
116	tmpfs_truncate(callid, &call);	119	tmpfs_truncate(callid, &call);
117	break;	120	break;
118	case VFS_DESTROY:	121	case VFS_DESTROY:
119	tmpfs_destroy(callid, &call);	122	tmpfs_destroy(callid, &call);
120	break;	123	break;
121	default:	124	default:
122	ipc_answer_0(callid, ENOTSUP);	125	ipc_answer_0(callid, ENOTSUP);
123	break;	126	break;
124	}	127	}
125	}	128	}
126	}	129	}
127		130
128	int main(int argc, char **argv)	131	int main(int argc, char **argv)
129	{	132	{
130	int vfs_phone;	133	int vfs_phone;
131		134
132	printf("TMPFS: HelenOS TMPFS file system server.\n");	135	printf("TMPFS: HelenOS TMPFS file system server.\n");
133		136
134	vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);	137	vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);
135	while (vfs_phone < EOK) {	138	while (vfs_phone < EOK) {
136	usleep(10000);	139	usleep(10000);
137	vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);	140	vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);
138	}	141	}
139		142
140	int rc;	143	int rc;
141	rc = fs_register(vfs_phone, &tmpfs_reg, &tmpfs_vfs_info,	144	rc = fs_register(vfs_phone, &tmpfs_reg, &tmpfs_vfs_info,
142	tmpfs_connection);	145	tmpfs_connection);
143	if (rc != EOK) {	146	if (rc != EOK) {
144	printf("Failed to register the TMPFS file system (%d)\n", rc);	147	printf("Failed to register the TMPFS file system (%d)\n", rc);
145	return rc;	148	return rc;
146	}	149	}
147		150
148	dprintf("TMPFS filesystem registered, fs_handle=%d.\n",	151	dprintf("TMPFS filesystem registered, fs_handle=%d.\n",
149	tmpfs_reg.fs_handle);	152	tmpfs_reg.fs_handle);
150		153
151	async_manager();	154	async_manager();
152	/* not reached */	155	/* not reached */
153	return 0;	156	return 0;
154	}	157	}
155		158
156	/**	159	/**
157	* @}	160	* @}
158	*/	161	*/
159		162

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/tmpfs/tmpfs.c – Rev 2742 → 2958