source: mainline/uspace/srv/vfs/vfs.c@ 5a5abf1

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 5a5abf1 was 5a5abf1, checked in by Jakub Jermar <jakub@…>, 16 years ago

Allow VFS to interconnect two file system servers.
  • Property mode set to 100644
File size: 5.1 KB
Line 
1/*
2 * Copyright (c) 2008 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup fs
30 * @{
31 */
32
33/**
34 * @file vfs.c
35 * @brief VFS service for HelenOS.
36 */
37
38#include <ipc/ipc.h>
39#include <ipc/services.h>
40#include <async.h>
41#include <errno.h>
42#include <stdio.h>
43#include <bool.h>
44#include <string.h>
45#include <as.h>
46#include <libadt/list.h>
47#include <atomic.h>
48#include "vfs.h"
49
50#define NAME "vfs"
51
52static void vfs_connection(ipc_callid_t iid, ipc_call_t *icall)
53{
54 bool keep_on_going = 1;
55
56 /*
57 * The connection was opened via the IPC_CONNECT_ME_TO call.
58 * This call needs to be answered.
59 */
60 ipc_answer_0(iid, EOK);
61
62 /*
63 * Here we enter the main connection fibril loop.
64 * The logic behind this loop and the protocol is that we'd like to keep
65 * each connection open until the client hangs up. When the client hangs
66 * up, we will free its VFS state. The act of hanging up the connection
67 * by the client is equivalent to client termination because we cannot
68 * distinguish one from the other. On the other hand, the client can
69 * hang up arbitrarily if it has no open files and reestablish the
70 * connection later.
71 */
72 while (keep_on_going) {
73 ipc_callid_t callid;
74 ipc_call_t call;
75 int phone;
76 fs_handle_t fs_handle;
77
78 callid = async_get_call(&call);
79
80 switch (IPC_GET_METHOD(call)) {
81 case IPC_M_PHONE_HUNGUP:
82 keep_on_going = false;
83 break;
84 case IPC_M_CONNECT_ME_TO:
85 /*
86 * Connect the client file system to another one.
87 */
88 /* FIXME:
89 * Prevent ordinary clients from connecting to file
90 * system servers directly. This should be solved by
91 * applying some security mechanisms.
92 */
93 fs_handle = IPC_GET_ARG1(call);
94 phone = vfs_grab_phone(fs_handle);
95 (void) ipc_forward_fast(callid, phone, 0, 0, 0,
96 IPC_FF_NONE);
97 vfs_release_phone(phone);
98 break;
99 case VFS_REGISTER:
100 vfs_register(callid, &call);
101 /*
102 * Keep the connection open so that a file system can
103 * later ask us to connect it to another file system.
104 * This is necessary to support non-root mounts.
105 */
106 break;
107 case VFS_MOUNT:
108 vfs_mount(callid, &call);
109 break;
110 case VFS_OPEN:
111 vfs_open(callid, &call);
112 break;
113 case VFS_CLOSE:
114 vfs_close(callid, &call);
115 break;
116 case VFS_READ:
117 vfs_read(callid, &call);
118 break;
119 case VFS_WRITE:
120 vfs_write(callid, &call);
121 break;
122 case VFS_SEEK:
123 vfs_seek(callid, &call);
124 break;
125 case VFS_TRUNCATE:
126 vfs_truncate(callid, &call);
127 break;
128 case VFS_MKDIR:
129 vfs_mkdir(callid, &call);
130 break;
131 case VFS_UNLINK:
132 vfs_unlink(callid, &call);
133 break;
134 case VFS_RENAME:
135 vfs_rename(callid, &call);
136 break;
137 default:
138 ipc_answer_0(callid, ENOTSUP);
139 break;
140 }
141 }
142
143 /* TODO: cleanup after the client */
144
145}
146
147int main(int argc, char **argv)
148{
149 ipcarg_t phonead;
150
151 printf(NAME ": HelenOS VFS server\n");
152
153 /*
154 * Initialize the list of registered file systems.
155 */
156 list_initialize(&fs_head);
157
158 /*
159 * Initialize VFS node hash table.
160 */
161 if (!vfs_nodes_init()) {
162 printf(NAME ": Failed to initialize VFS node hash table\n");
163 return ENOMEM;
164 }
165
166 /*
167 * Allocate and initialize the Path Lookup Buffer.
168 */
169 list_initialize(&plb_head);
170 plb = as_get_mappable_page(PLB_SIZE);
171 if (!plb) {
172 printf(NAME ": Cannot allocate a mappable piece of address space\n");
173 return ENOMEM;
174 }
175 if (as_area_create(plb, PLB_SIZE, AS_AREA_READ | AS_AREA_WRITE |
176 AS_AREA_CACHEABLE) != plb) {
177 printf(NAME ": Cannot create address space area\n");
178 return ENOMEM;
179 }
180 memset(plb, 0, PLB_SIZE);
181
182 /*
183 * Set a connectio handling function/fibril.
184 */
185 async_set_client_connection(vfs_connection);
186
187 /*
188 * Register at the naming service.
189 */
190 ipc_connect_to_me(PHONE_NS, SERVICE_VFS, 0, 0, &phonead);
191
192 /*
193 * Start accepting connections.
194 */
195 printf(NAME ": Accepting connections\n");
196 async_manager();
197 return 0;
198}
199
200/**
201 * @}
202 */
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