source: mainline/uspace/lib/libfs/libfs.c@ 1313ee9

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 1313ee9 was 1313ee9, checked in by Martin Decky <martin@…>, 16 years ago

introduce device namespaces

  • add support for explicit open in libfs (needed by devfs, but also possibly for other filesystems which need to track some stateful information)
  • extend libfs to be more generic, make proper adjustments to libc, tmpfs and fat
  • various updates to make use of the device namespaces
  • code cleanup
  • Property mode set to 100644
File size: 14.1 KB
Line 
1/*
2 * Copyright (c) 2009 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 libfs
30 * @{
31 */
32/**
33 * @file
34 * Glue code which is common to all FS implementations.
35 */
36
37#include "libfs.h"
38#include "../../srv/vfs/vfs.h"
39#include <errno.h>
40#include <async.h>
41#include <ipc/ipc.h>
42#include <as.h>
43#include <assert.h>
44#include <dirent.h>
45#include <mem.h>
46#include <sys/stat.h>
47
48#define on_error(rc, action) \
49 do { \
50 if ((rc) != EOK) \
51 action; \
52 } while (0)
53
54#define combine_rc(rc1, rc2) \
55 ((rc1) == EOK ? (rc2) : (rc1))
56
57#define answer_and_return(rid, rc) \
58 do { \
59 ipc_answer_0((rid), (rc)); \
60 return; \
61 } while (0)
62
63/** Register file system server.
64 *
65 * This function abstracts away the tedious registration protocol from
66 * file system implementations and lets them to reuse this registration glue
67 * code.
68 *
69 * @param vfs_phone Open phone for communication with VFS.
70 * @param reg File system registration structure. It will be
71 * initialized by this function.
72 * @param info VFS info structure supplied by the file system
73 * implementation.
74 * @param conn Connection fibril for handling all calls originating in
75 * VFS.
76 *
77 * @return EOK on success or a non-zero error code on errror.
78 *
79 */
80int fs_register(int vfs_phone, fs_reg_t *reg, vfs_info_t *info,
81 async_client_conn_t conn)
82{
83 /*
84 * Tell VFS that we are here and want to get registered.
85 * We use the async framework because VFS will answer the request
86 * out-of-order, when it knows that the operation succeeded or failed.
87 */
88 ipc_call_t answer;
89 aid_t req = async_send_0(vfs_phone, VFS_IN_REGISTER, &answer);
90
91 /*
92 * Send our VFS info structure to VFS.
93 */
94 int rc = async_data_write_start(vfs_phone, info, sizeof(*info));
95 if (rc != EOK) {
96 async_wait_for(req, NULL);
97 return rc;
98 }
99
100 /*
101 * Ask VFS for callback connection.
102 */
103 ipc_connect_to_me(vfs_phone, 0, 0, 0, &reg->vfs_phonehash);
104
105 /*
106 * Allocate piece of address space for PLB.
107 */
108 reg->plb_ro = as_get_mappable_page(PLB_SIZE);
109 if (!reg->plb_ro) {
110 async_wait_for(req, NULL);
111 return ENOMEM;
112 }
113
114 /*
115 * Request sharing the Path Lookup Buffer with VFS.
116 */
117 rc = async_share_in_start_0_0(vfs_phone, reg->plb_ro, PLB_SIZE);
118 if (rc) {
119 async_wait_for(req, NULL);
120 return rc;
121 }
122
123 /*
124 * Pick up the answer for the request to the VFS_IN_REQUEST call.
125 */
126 async_wait_for(req, NULL);
127 reg->fs_handle = (int) IPC_GET_ARG1(answer);
128
129 /*
130 * Create a connection fibril to handle the callback connection.
131 */
132 async_new_connection(reg->vfs_phonehash, 0, NULL, conn);
133
134 /*
135 * Tell the async framework that other connections are to be handled by
136 * the same connection fibril as well.
137 */
138 async_set_client_connection(conn);
139
140 return IPC_GET_RETVAL(answer);
141}
142
143void fs_node_initialize(fs_node_t *fn)
144{
145 memset(fn, 0, sizeof(fs_node_t));
146}
147
148void libfs_mount(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
149 ipc_call_t *request)
150{
151 dev_handle_t mp_dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
152 fs_index_t mp_fs_index = (fs_index_t) IPC_GET_ARG2(*request);
153 fs_handle_t mr_fs_handle = (fs_handle_t) IPC_GET_ARG3(*request);
154 dev_handle_t mr_dev_handle = (dev_handle_t) IPC_GET_ARG4(*request);
155 int res;
156 ipcarg_t rc;
157
158 ipc_call_t call;
159 ipc_callid_t callid;
160
161 /* Accept the phone */
162 callid = async_get_call(&call);
163 int mountee_phone = (int)IPC_GET_ARG1(call);
164 if ((IPC_GET_METHOD(call) != IPC_M_CONNECTION_CLONE) ||
165 (mountee_phone < 0)) {
166 ipc_answer_0(callid, EINVAL);
167 ipc_answer_0(rid, EINVAL);
168 return;
169 }
170
171 /* Acknowledge the mountee_phone */
172 ipc_answer_0(callid, EOK);
173
174 res = async_data_write_receive(&callid, NULL);
175 if (!res) {
176 ipc_hangup(mountee_phone);
177 ipc_answer_0(callid, EINVAL);
178 ipc_answer_0(rid, EINVAL);
179 return;
180 }
181
182 fs_node_t *fn;
183 res = ops->node_get(&fn, mp_dev_handle, mp_fs_index);
184 if ((res != EOK) || (!fn)) {
185 ipc_hangup(mountee_phone);
186 ipc_answer_0(callid, combine_rc(res, ENOENT));
187 ipc_answer_0(rid, combine_rc(res, ENOENT));
188 return;
189 }
190
191 if (fn->mp_data.mp_active) {
192 ipc_hangup(mountee_phone);
193 (void) ops->node_put(fn);
194 ipc_answer_0(callid, EBUSY);
195 ipc_answer_0(rid, EBUSY);
196 return;
197 }
198
199 rc = async_req_0_0(mountee_phone, IPC_M_CONNECT_ME);
200 if (rc != EOK) {
201 ipc_hangup(mountee_phone);
202 (void) ops->node_put(fn);
203 ipc_answer_0(callid, rc);
204 ipc_answer_0(rid, rc);
205 return;
206 }
207
208 ipc_call_t answer;
209 aid_t msg = async_send_1(mountee_phone, VFS_OUT_MOUNTED, mr_dev_handle,
210 &answer);
211 ipc_forward_fast(callid, mountee_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
212 async_wait_for(msg, &rc);
213
214 if (rc == EOK) {
215 fn->mp_data.mp_active = true;
216 fn->mp_data.fs_handle = mr_fs_handle;
217 fn->mp_data.dev_handle = mr_dev_handle;
218 fn->mp_data.phone = mountee_phone;
219 }
220
221 /*
222 * Do not release the FS node so that it stays in memory.
223 */
224 ipc_answer_3(rid, rc, IPC_GET_ARG1(answer), IPC_GET_ARG2(answer),
225 IPC_GET_ARG3(answer));
226}
227
228/** Lookup VFS triplet by name in the file system name space.
229 *
230 * The path passed in the PLB must be in the canonical file system path format
231 * as returned by the canonify() function.
232 *
233 * @param ops libfs operations structure with function pointers to
234 * file system implementation
235 * @param fs_handle File system handle of the file system where to perform
236 * the lookup.
237 * @param rid Request ID of the VFS_OUT_LOOKUP request.
238 * @param request VFS_OUT_LOOKUP request data itself.
239 *
240 */
241void libfs_lookup(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
242 ipc_call_t *request)
243{
244 unsigned int first = IPC_GET_ARG1(*request);
245 unsigned int last = IPC_GET_ARG2(*request);
246 unsigned int next = first;
247 dev_handle_t dev_handle = IPC_GET_ARG3(*request);
248 int lflag = IPC_GET_ARG4(*request);
249 fs_index_t index = IPC_GET_ARG5(*request);
250 char component[NAME_MAX + 1];
251 int len;
252 int rc;
253
254 if (last < next)
255 last += PLB_SIZE;
256
257 fs_node_t *par = NULL;
258 fs_node_t *cur = NULL;
259 fs_node_t *tmp = NULL;
260
261 rc = ops->root_get(&cur, dev_handle);
262 on_error(rc, goto out_with_answer);
263
264 if (cur->mp_data.mp_active) {
265 ipc_forward_slow(rid, cur->mp_data.phone, VFS_OUT_LOOKUP,
266 next, last, cur->mp_data.dev_handle, lflag, index,
267 IPC_FF_ROUTE_FROM_ME);
268 (void) ops->node_put(cur);
269 return;
270 }
271
272 /* Eat slash */
273 if (ops->plb_get_char(next) == '/')
274 next++;
275
276 while (next <= last) {
277 bool has_children;
278
279 rc = ops->has_children(&has_children, cur);
280 on_error(rc, goto out_with_answer);
281 if (!has_children)
282 break;
283
284 /* Collect the component */
285 len = 0;
286 while ((next <= last) && (ops->plb_get_char(next) != '/')) {
287 if (len + 1 == NAME_MAX) {
288 /* Component length overflow */
289 ipc_answer_0(rid, ENAMETOOLONG);
290 goto out;
291 }
292 component[len++] = ops->plb_get_char(next);
293 /* Process next character */
294 next++;
295 }
296
297 assert(len);
298 component[len] = '\0';
299 /* Eat slash */
300 next++;
301
302 /* Match the component */
303 rc = ops->match(&tmp, cur, component);
304 on_error(rc, goto out_with_answer);
305
306 if ((tmp) && (tmp->mp_data.mp_active)) {
307 if (next > last)
308 next = last = first;
309 else
310 next--;
311
312 ipc_forward_slow(rid, tmp->mp_data.phone,
313 VFS_OUT_LOOKUP, next, last, tmp->mp_data.dev_handle,
314 lflag, index, IPC_FF_ROUTE_FROM_ME);
315 (void) ops->node_put(cur);
316 (void) ops->node_put(tmp);
317 if (par)
318 (void) ops->node_put(par);
319 return;
320 }
321
322 /* Handle miss: match amongst siblings */
323 if (!tmp) {
324 if (next <= last) {
325 /* There are unprocessed components */
326 ipc_answer_0(rid, ENOENT);
327 goto out;
328 }
329
330 /* Miss in the last component */
331 if (lflag & (L_CREATE | L_LINK)) {
332 /* Request to create a new link */
333 if (!ops->is_directory(cur)) {
334 ipc_answer_0(rid, ENOTDIR);
335 goto out;
336 }
337
338 fs_node_t *fn;
339 if (lflag & L_CREATE)
340 rc = ops->create(&fn, dev_handle,
341 lflag);
342 else
343 rc = ops->node_get(&fn, dev_handle,
344 index);
345 on_error(rc, goto out_with_answer);
346
347 if (fn) {
348 rc = ops->link(cur, fn, component);
349 if (rc != EOK) {
350 if (lflag & L_CREATE)
351 (void) ops->destroy(fn);
352 ipc_answer_0(rid, rc);
353 } else {
354 ipc_answer_5(rid, EOK,
355 fs_handle, dev_handle,
356 ops->index_get(fn),
357 ops->size_get(fn),
358 ops->lnkcnt_get(fn));
359 (void) ops->node_put(fn);
360 }
361 } else
362 ipc_answer_0(rid, ENOSPC);
363
364 goto out;
365 }
366
367 ipc_answer_0(rid, ENOENT);
368 goto out;
369 }
370
371 if (par) {
372 rc = ops->node_put(par);
373 on_error(rc, goto out_with_answer);
374 }
375
376 /* Descend one level */
377 par = cur;
378 cur = tmp;
379 tmp = NULL;
380 }
381
382 /* Handle miss: excessive components */
383 if (next <= last) {
384 bool has_children;
385 rc = ops->has_children(&has_children, cur);
386 on_error(rc, goto out_with_answer);
387
388 if (has_children)
389 goto skip_miss;
390
391 if (lflag & (L_CREATE | L_LINK)) {
392 if (!ops->is_directory(cur)) {
393 ipc_answer_0(rid, ENOTDIR);
394 goto out;
395 }
396
397 /* Collect next component */
398 len = 0;
399 while (next <= last) {
400 if (ops->plb_get_char(next) == '/') {
401 /* More than one component */
402 ipc_answer_0(rid, ENOENT);
403 goto out;
404 }
405
406 if (len + 1 == NAME_MAX) {
407 /* Component length overflow */
408 ipc_answer_0(rid, ENAMETOOLONG);
409 goto out;
410 }
411
412 component[len++] = ops->plb_get_char(next);
413 /* Process next character */
414 next++;
415 }
416
417 assert(len);
418 component[len] = '\0';
419
420 fs_node_t *fn;
421 if (lflag & L_CREATE)
422 rc = ops->create(&fn, dev_handle, lflag);
423 else
424 rc = ops->node_get(&fn, dev_handle, index);
425 on_error(rc, goto out_with_answer);
426
427 if (fn) {
428 rc = ops->link(cur, fn, component);
429 if (rc != EOK) {
430 if (lflag & L_CREATE)
431 (void) ops->destroy(fn);
432 ipc_answer_0(rid, rc);
433 } else {
434 ipc_answer_5(rid, EOK,
435 fs_handle, dev_handle,
436 ops->index_get(fn),
437 ops->size_get(fn),
438 ops->lnkcnt_get(fn));
439 (void) ops->node_put(fn);
440 }
441 } else
442 ipc_answer_0(rid, ENOSPC);
443
444 goto out;
445 }
446
447 ipc_answer_0(rid, ENOENT);
448 goto out;
449 }
450
451skip_miss:
452
453 /* Handle hit */
454 if (lflag & L_UNLINK) {
455 unsigned int old_lnkcnt = ops->lnkcnt_get(cur);
456 rc = ops->unlink(par, cur, component);
457 ipc_answer_5(rid, (ipcarg_t) rc, fs_handle, dev_handle,
458 ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
459 goto out;
460 }
461
462 if (((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) ||
463 (lflag & L_LINK)) {
464 ipc_answer_0(rid, EEXIST);
465 goto out;
466 }
467
468 if ((lflag & L_FILE) && (ops->is_directory(cur))) {
469 ipc_answer_0(rid, EISDIR);
470 goto out;
471 }
472
473 if ((lflag & L_DIRECTORY) && (ops->is_file(cur))) {
474 ipc_answer_0(rid, ENOTDIR);
475 goto out;
476 }
477
478out_with_answer:
479
480 if (rc == EOK) {
481 if (lflag & L_OPEN)
482 rc = ops->node_open(cur);
483
484 ipc_answer_5(rid, rc, fs_handle, dev_handle,
485 ops->index_get(cur), ops->size_get(cur),
486 ops->lnkcnt_get(cur));
487 } else
488 ipc_answer_0(rid, rc);
489
490out:
491
492 if (par)
493 (void) ops->node_put(par);
494
495 if (cur)
496 (void) ops->node_put(cur);
497
498 if (tmp)
499 (void) ops->node_put(tmp);
500}
501
502void libfs_stat(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
503 ipc_call_t *request)
504{
505 dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
506 fs_index_t index = (fs_index_t) IPC_GET_ARG2(*request);
507
508 fs_node_t *fn;
509 int rc = ops->node_get(&fn, dev_handle, index);
510 on_error(rc, answer_and_return(rid, rc));
511
512 ipc_callid_t callid;
513 size_t size;
514 if ((!async_data_read_receive(&callid, &size)) ||
515 (size != sizeof(struct stat))) {
516 ops->node_put(fn);
517 ipc_answer_0(callid, EINVAL);
518 ipc_answer_0(rid, EINVAL);
519 return;
520 }
521
522 struct stat stat;
523 memset(&stat, 0, sizeof(struct stat));
524
525 stat.fs_handle = fs_handle;
526 stat.dev_handle = dev_handle;
527 stat.index = index;
528 stat.lnkcnt = ops->lnkcnt_get(fn);
529 stat.is_file = ops->is_file(fn);
530 stat.is_directory = ops->is_directory(fn);
531 stat.size = ops->size_get(fn);
532 stat.device = ops->device_get(fn);
533
534 ops->node_put(fn);
535
536 async_data_read_finalize(callid, &stat, sizeof(struct stat));
537 ipc_answer_0(rid, EOK);
538}
539
540/** Open VFS triplet.
541 *
542 * @param ops libfs operations structure with function pointers to
543 * file system implementation
544 * @param rid Request ID of the VFS_OUT_OPEN_NODE request.
545 * @param request VFS_OUT_OPEN_NODE request data itself.
546 *
547 */
548void libfs_open_node(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
549 ipc_call_t *request)
550{
551 dev_handle_t dev_handle = IPC_GET_ARG1(*request);
552 fs_index_t index = IPC_GET_ARG2(*request);
553 fs_node_t *fn;
554 int rc;
555
556 rc = ops->node_get(&fn, dev_handle, index);
557 on_error(rc, answer_and_return(rid, rc));
558
559 if (fn == NULL) {
560 ipc_answer_0(rid, ENOENT);
561 return;
562 }
563
564 rc = ops->node_open(fn);
565 ipc_answer_3(rid, rc, ops->size_get(fn), ops->lnkcnt_get(fn),
566 (ops->is_file(fn) ? L_FILE : 0) | (ops->is_directory(fn) ? L_DIRECTORY : 0));
567
568 (void) ops->node_put(fn);
569}
570
571/** @}
572 */
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