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2642 jermar 1
/*
2747 jermar 2
 * Copyright (c) 2008 Jakub Jermar
2642 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 libfs
30
 * @{
31
 */
32
/**
33
 * @file
34
 * Glue code which is commonod to all FS implementations.
35
 */
36
 
37
#include "libfs.h" 
2643 jermar 38
#include "../../srv/vfs/vfs.h"
39
#include <errno.h>
40
#include <async.h>
41
#include <ipc/ipc.h>
42
#include <as.h>
2747 jermar 43
#include <assert.h>
44
#include <dirent.h>
2642 jermar 45
 
2643 jermar 46
/** Register file system server.
47
 *
48
 * This function abstracts away the tedious registration protocol from
49
 * file system implementations and lets them to reuse this registration glue
50
 * code.
51
 *
52
 * @param vfs_phone Open phone for communication with VFS.
53
 * @param reg       File system registration structure. It will be
54
 *          initialized by this function.
55
 * @param info      VFS info structure supplied by the file system
56
 *          implementation.
57
 * @param conn      Connection fibril for handling all calls originating in
58
 *          VFS.
59
 *
60
 * @return      EOK on success or a non-zero error code on errror.
61
 */
62
int fs_register(int vfs_phone, fs_reg_t *reg, vfs_info_t *info,
63
    async_client_conn_t conn)
64
{
65
    /*
66
     * Tell VFS that we are here and want to get registered.
67
     * We use the async framework because VFS will answer the request
68
     * out-of-order, when it knows that the operation succeeded or failed.
69
     */
70
    ipc_call_t answer;
71
    aid_t req = async_send_0(vfs_phone, VFS_REGISTER, &answer);
72
 
73
    /*
74
     * Send our VFS info structure to VFS.
75
     */
2678 jermar 76
    int rc = ipc_data_write_start(vfs_phone, info, sizeof(*info));
2643 jermar 77
    if (rc != EOK) {
78
        async_wait_for(req, NULL);
79
        return rc;
80
    }
81
 
82
    /*
83
     * Ask VFS for callback connection.
84
     */
85
    ipc_connect_to_me(vfs_phone, 0, 0, 0, &reg->vfs_phonehash);
86
 
87
    /*
88
     * Allocate piece of address space for PLB.
89
     */
90
    reg->plb_ro = as_get_mappable_page(PLB_SIZE);
91
    if (!reg->plb_ro) {
92
        async_wait_for(req, NULL);
93
        return ENOMEM;
94
    }
95
 
96
    /*
97
     * Request sharing the Path Lookup Buffer with VFS.
98
     */
2678 jermar 99
    rc = ipc_share_in_start_0_0(vfs_phone, reg->plb_ro, PLB_SIZE);
2643 jermar 100
    if (rc) {
101
        async_wait_for(req, NULL);
102
        return rc;
103
    }
104
 
105
    /*
106
     * Pick up the answer for the request to the VFS_REQUEST call.
107
     */
108
    async_wait_for(req, NULL);
109
    reg->fs_handle = (int) IPC_GET_ARG1(answer);
110
 
111
    /*
112
     * Create a connection fibril to handle the callback connection.
113
     */
114
    async_new_connection(reg->vfs_phonehash, 0, NULL, conn);
115
 
116
    /*
117
     * Tell the async framework that other connections are to be handled by
118
     * the same connection fibril as well.
119
     */
120
    async_set_client_connection(conn);
121
 
122
    return IPC_GET_RETVAL(answer);
123
}
124
 
2750 jermar 125
/** Lookup VFS triplet by name in the file system name space.
126
 *
2751 jermar 127
 * The path passed in the PLB must be in the canonical file system path format
128
 * as returned by the canonify() function.
129
 *
2750 jermar 130
 * @param ops       libfs operations structure with function pointers to
131
 *          file system implementation
132
 * @param fs_handle File system handle of the file system where to perform
133
 *          the lookup.
134
 * @param rid       Request ID of the VFS_LOOKUP request.
135
 * @param request   VFS_LOOKUP request data itself.
136
 */
2747 jermar 137
void libfs_lookup(libfs_ops_t *ops, int fs_handle, ipc_callid_t rid,
138
    ipc_call_t *request)
139
{
140
    unsigned next = IPC_GET_ARG1(*request);
141
    unsigned last = IPC_GET_ARG2(*request);
142
    int dev_handle = IPC_GET_ARG3(*request);
143
    int lflag = IPC_GET_ARG4(*request);
2763 jermar 144
    int index = IPC_GET_ARG5(*request); /* when L_LINK specified */
2747 jermar 145
 
146
    if (last < next)
147
        last += PLB_SIZE;
148
 
2758 jermar 149
    void *par = NULL;
2747 jermar 150
    void *cur = ops->root_get();
151
    void *tmp = ops->child_get(cur);
152
 
153
    if (ops->plb_get_char(next) == '/')
154
        next++;     /* eat slash */
155
 
156
    char component[NAME_MAX + 1];
157
    int len = 0;
158
    while (tmp && next <= last) {
159
 
160
        /* collect the component */
161
        if (ops->plb_get_char(next) != '/') {
162
            if (len + 1 == NAME_MAX) {
163
                /* comopnent length overflow */
164
                ipc_answer_0(rid, ENAMETOOLONG);
165
                return;
166
            }
167
            component[len++] = ops->plb_get_char(next);
168
            next++; /* process next character */
169
            if (next <= last)
170
                continue;
171
        }
172
 
173
        assert(len);
174
        component[len] = '\0';
175
        next++;     /* eat slash */
176
        len = 0;
177
 
178
        /* match the component */
2760 jermar 179
        while (tmp && !ops->match(cur, tmp, component))
2747 jermar 180
            tmp = ops->sibling_get(tmp);
181
 
182
        /* handle miss: match amongst siblings */
183
        if (!tmp) {
2763 jermar 184
            if (next <= last) {
185
                /* there are unprocessed components */
186
                ipc_answer_0(rid, ENOENT);
187
                return;
188
            }
189
            /* miss in the last component */
190
            if (lflag & (L_CREATE | L_LINK)) {
191
                /* request to create a new link */
2747 jermar 192
                if (!ops->is_directory(cur)) {
193
                    ipc_answer_0(rid, ENOTDIR);
194
                    return;
2763 jermar 195
                }
196
                void *nodep;
197
                if (lflag & L_CREATE)
198
                    nodep = ops->create(lflag);
199
                else
200
                    nodep = ops->node_get(fs_handle,
201
                        dev_handle, index);
2747 jermar 202
                if (nodep) {
203
                    if (!ops->link(cur, nodep, component)) {
2763 jermar 204
                        if (lflag & L_CREATE)
205
                            ops->destroy(nodep);
2747 jermar 206
                        ipc_answer_0(rid, ENOSPC);
207
                    } else {
208
                        ipc_answer_5(rid, EOK,
209
                            fs_handle, dev_handle,
2763 jermar 210
                            ops->index_get(nodep),
211
                            ops->size_get(nodep),
2747 jermar 212
                            ops->lnkcnt_get(nodep));
213
                    }
214
                } else {
215
                    ipc_answer_0(rid, ENOSPC);
216
                }
217
                return;
2763 jermar 218
            } else if (lflag & L_PARENT) {
219
                /* return parent */
220
                ipc_answer_5(rid, EOK, fs_handle, dev_handle,
221
                    ops->index_get(cur), ops->size_get(cur),
222
                    ops->lnkcnt_get(cur));
223
            }
2747 jermar 224
            ipc_answer_0(rid, ENOENT);
225
            return;
226
        }
227
 
228
        /* descend one level */
2758 jermar 229
        par = cur;
2747 jermar 230
        cur = tmp;
231
        tmp = ops->child_get(tmp);
232
    }
233
 
234
    /* handle miss: excessive components */
235
    if (!tmp && next <= last) {
2763 jermar 236
        if (lflag & (L_CREATE | L_LINK)) {
2747 jermar 237
            if (!ops->is_directory(cur)) {
238
                ipc_answer_0(rid, ENOTDIR);
239
                return;
240
            }
241
 
242
            /* collect next component */
243
            while (next <= last) {
244
                if (ops->plb_get_char(next) == '/') {
245
                    /* more than one component */
246
                    ipc_answer_0(rid, ENOENT);
247
                    return;
248
                }
249
                if (len + 1 == NAME_MAX) {
250
                    /* component length overflow */
251
                    ipc_answer_0(rid, ENAMETOOLONG);
252
                    return;
253
                }
254
                component[len++] = ops->plb_get_char(next);
255
                next++; /* process next character */
256
            }
257
            assert(len);
258
            component[len] = '\0';
259
            len = 0;
260
 
2763 jermar 261
            void *nodep;
262
            if (lflag & L_CREATE)
263
                nodep = ops->create(lflag);
264
            else
265
                nodep = ops->node_get(fs_handle, dev_handle,
266
                    index);
2747 jermar 267
            if (nodep) {
268
                if (!ops->link(cur, nodep, component)) {
2763 jermar 269
                    if (lflag & L_CREATE)
270
                        ops->destroy(nodep);
2747 jermar 271
                    ipc_answer_0(rid, ENOSPC);
272
                } else {
273
                    ipc_answer_5(rid, EOK,
274
                        fs_handle, dev_handle,
2763 jermar 275
                        ops->index_get(nodep),
276
                        ops->size_get(nodep),
2747 jermar 277
                        ops->lnkcnt_get(nodep));
278
                }
279
            } else {
280
                ipc_answer_0(rid, ENOSPC);
281
            }
282
            return;
283
        }
284
        ipc_answer_0(rid, ENOENT);
285
        return;
286
    }
287
 
288
    /* handle hit */
2763 jermar 289
    if (lflag & L_PARENT) {
290
        cur = par;
291
        if (!cur) {
292
            ipc_answer_0(rid, ENOENT);
293
            return;
294
        }
295
    }
296
    if (lflag & L_UNLINK) {
2747 jermar 297
        unsigned old_lnkcnt = ops->lnkcnt_get(cur);
2758 jermar 298
        int res = ops->unlink(par, cur);
2747 jermar 299
        ipc_answer_5(rid, (ipcarg_t)res, fs_handle, dev_handle,
300
            ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
301
        return;
302
    }
2763 jermar 303
    if (((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) ||
304
        (lflag & L_LINK)) {
2747 jermar 305
        ipc_answer_0(rid, EEXIST);
306
        return;
307
    }
308
    if ((lflag & L_FILE) && (ops->is_directory(cur))) {
309
        ipc_answer_0(rid, EISDIR);
310
        return;
311
    }
312
    if ((lflag & L_DIRECTORY) && (ops->is_file(cur))) {
313
        ipc_answer_0(rid, ENOTDIR);
314
        return;
315
    }
316
 
317
    ipc_answer_5(rid, EOK, fs_handle, dev_handle, ops->index_get(cur),
318
        ops->size_get(cur), ops->lnkcnt_get(cur));
319
}
320
 
2642 jermar 321
/** @}
322
 */