source: mainline/uspace/srv/fs/tmpfs/tmpfs.c@ 7329e6a

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 7329e6a was 3c11713, checked in by Jakub Jermar <jakub@…>, 15 years ago

Add dummy libfs unmount support and change all file systems to use it.
Add dummy VFS_OUT_UNMOUNTED support to all file systems.
  • Property mode set to 100644
File size: 5.1 KB
Line 
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 tmpfs.c
36 * @brief File system driver for in-memory file system.
37 *
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
40 * stored in a tmpfs file system is lost.
41 */
42
43#include "tmpfs.h"
44#include <ipc/ipc.h>
45#include <ipc/services.h>
46#include <async.h>
47#include <errno.h>
48#include <unistd.h>
49#include <stdio.h>
50#include <task.h>
51#include <libfs.h>
52#include "../../vfs/vfs.h"
53
54#define NAME "tmpfs"
55
56
57vfs_info_t tmpfs_vfs_info = {
58 .name = NAME,
59};
60
61fs_reg_t tmpfs_reg;
62
63/**
64 * This connection fibril processes VFS requests from VFS.
65 *
66 * In order to support simultaneous VFS requests, our design is as follows.
67 * The connection fibril accepts VFS requests from VFS. If there is only one
68 * instance of the fibril, VFS will need to serialize all VFS requests it sends
69 * to FAT. To overcome this bottleneck, VFS can send TMPFS the
70 * IPC_M_CONNECT_ME_TO call. In that case, a new connection fibril will be
71 * created, which in turn will accept the call. Thus, a new phone will be
72 * opened for VFS.
73 *
74 * There are few issues with this arrangement. First, VFS can run out of
75 * available phones. In that case, VFS can close some other phones or use one
76 * phone for more serialized requests. Similarily, TMPFS can refuse to duplicate
77 * the connection. VFS should then just make use of already existing phones and
78 * route its requests through them. To avoid paying the fibril creation price
79 * upon each request, TMPFS might want to keep the connections open after the
80 * request has been completed.
81 */
82static void tmpfs_connection(ipc_callid_t iid, ipc_call_t *icall)
83{
84 if (iid) {
85 /*
86 * This only happens for connections opened by
87 * IPC_M_CONNECT_ME_TO calls as opposed to callback connections
88 * created by IPC_M_CONNECT_TO_ME.
89 */
90 ipc_answer_0(iid, EOK);
91 }
92
93 dprintf(NAME ": connection opened\n");
94 while (1) {
95 ipc_callid_t callid;
96 ipc_call_t call;
97
98 callid = async_get_call(&call);
99 switch (IPC_GET_METHOD(call)) {
100 case IPC_M_PHONE_HUNGUP:
101 return;
102 case VFS_OUT_MOUNTED:
103 tmpfs_mounted(callid, &call);
104 break;
105 case VFS_OUT_MOUNT:
106 tmpfs_mount(callid, &call);
107 break;
108 case VFS_OUT_UNMOUNTED:
109 tmpfs_unmounted(callid, &call);
110 break;
111 case VFS_OUT_UNMOUNT:
112 tmpfs_unmount(callid, &call);
113 break;
114 case VFS_OUT_LOOKUP:
115 tmpfs_lookup(callid, &call);
116 break;
117 case VFS_OUT_READ:
118 tmpfs_read(callid, &call);
119 break;
120 case VFS_OUT_WRITE:
121 tmpfs_write(callid, &call);
122 break;
123 case VFS_OUT_TRUNCATE:
124 tmpfs_truncate(callid, &call);
125 break;
126 case VFS_OUT_CLOSE:
127 tmpfs_close(callid, &call);
128 break;
129 case VFS_OUT_DESTROY:
130 tmpfs_destroy(callid, &call);
131 break;
132 case VFS_OUT_OPEN_NODE:
133 tmpfs_open_node(callid, &call);
134 break;
135 case VFS_OUT_STAT:
136 tmpfs_stat(callid, &call);
137 break;
138 case VFS_OUT_SYNC:
139 tmpfs_sync(callid, &call);
140 break;
141 default:
142 ipc_answer_0(callid, ENOTSUP);
143 break;
144 }
145 }
146}
147
148int main(int argc, char **argv)
149{
150 printf(NAME ": HelenOS TMPFS file system server\n");
151
152 if (!tmpfs_init()) {
153 printf(NAME ": failed to initialize TMPFS\n");
154 return -1;
155 }
156
157 int vfs_phone = ipc_connect_me_to_blocking(PHONE_NS, SERVICE_VFS, 0, 0);
158 if (vfs_phone < EOK) {
159 printf(NAME ": Unable to connect to VFS\n");
160 return -1;
161 }
162
163 int rc = fs_register(vfs_phone, &tmpfs_reg, &tmpfs_vfs_info,
164 tmpfs_connection);
165 if (rc != EOK) {
166 printf(NAME ": Failed to register file system (%d)\n", rc);
167 return rc;
168 }
169
170 printf(NAME ": Accepting connections\n");
171 task_retval(0);
172 async_manager();
173 /* not reached */
174 return 0;
175}
176
177/**
178 * @}
179 */
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