source: mainline/uspace/lib/libfs/libfs.c@ 3c11713

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 3c11713 was 3c11713, checked in by Jakub Jermar <jakub@…>, 16 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: 14.8 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
228void libfs_unmount(libfs_ops_t *ops, ipc_callid_t rid, ipc_call_t *request)
229{
230 ipc_answer_0(rid, ENOTSUP);
231}
232
233/** Lookup VFS triplet by name in the file system name space.
234 *
235 * The path passed in the PLB must be in the canonical file system path format
236 * as returned by the canonify() function.
237 *
238 * @param ops libfs operations structure with function pointers to
239 * file system implementation
240 * @param fs_handle File system handle of the file system where to perform
241 * the lookup.
242 * @param rid Request ID of the VFS_OUT_LOOKUP request.
243 * @param request VFS_OUT_LOOKUP request data itself.
244 *
245 */
246void libfs_lookup(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
247 ipc_call_t *request)
248{
249 unsigned int first = IPC_GET_ARG1(*request);
250 unsigned int last = IPC_GET_ARG2(*request);
251 unsigned int next = first;
252 dev_handle_t dev_handle = IPC_GET_ARG3(*request);
253 int lflag = IPC_GET_ARG4(*request);
254 fs_index_t index = IPC_GET_ARG5(*request);
255 char component[NAME_MAX + 1];
256 int len;
257 int rc;
258
259 if (last < next)
260 last += PLB_SIZE;
261
262 fs_node_t *par = NULL;
263 fs_node_t *cur = NULL;
264 fs_node_t *tmp = NULL;
265
266 rc = ops->root_get(&cur, dev_handle);
267 on_error(rc, goto out_with_answer);
268
269 if (cur->mp_data.mp_active) {
270 ipc_forward_slow(rid, cur->mp_data.phone, VFS_OUT_LOOKUP,
271 next, last, cur->mp_data.dev_handle, lflag, index,
272 IPC_FF_ROUTE_FROM_ME);
273 (void) ops->node_put(cur);
274 return;
275 }
276
277 /* Eat slash */
278 if (ops->plb_get_char(next) == '/')
279 next++;
280
281 while (next <= last) {
282 bool has_children;
283
284 rc = ops->has_children(&has_children, cur);
285 on_error(rc, goto out_with_answer);
286 if (!has_children)
287 break;
288
289 /* Collect the component */
290 len = 0;
291 while ((next <= last) && (ops->plb_get_char(next) != '/')) {
292 if (len + 1 == NAME_MAX) {
293 /* Component length overflow */
294 ipc_answer_0(rid, ENAMETOOLONG);
295 goto out;
296 }
297 component[len++] = ops->plb_get_char(next);
298 /* Process next character */
299 next++;
300 }
301
302 assert(len);
303 component[len] = '\0';
304 /* Eat slash */
305 next++;
306
307 /* Match the component */
308 rc = ops->match(&tmp, cur, component);
309 on_error(rc, goto out_with_answer);
310
311 /*
312 * If the matching component is a mount point, there are two
313 * legitimate semantics of the lookup operation. The first is
314 * the commonly used one in which the lookup crosses each mount
315 * point into the mounted file system. The second semantics is
316 * used mostly during unmount() and differs from the first one
317 * only in that the last mount point in the looked up path,
318 * which is also its last component, is not crossed.
319 */
320
321 if ((tmp) && (tmp->mp_data.mp_active) &&
322 (!(lflag & L_MP) || (next <= last))) {
323 if (next > last)
324 next = last = first;
325 else
326 next--;
327
328 ipc_forward_slow(rid, tmp->mp_data.phone,
329 VFS_OUT_LOOKUP, next, last, tmp->mp_data.dev_handle,
330 lflag, index, IPC_FF_ROUTE_FROM_ME);
331 (void) ops->node_put(cur);
332 (void) ops->node_put(tmp);
333 if (par)
334 (void) ops->node_put(par);
335 return;
336 }
337
338 /* Handle miss: match amongst siblings */
339 if (!tmp) {
340 if (next <= last) {
341 /* There are unprocessed components */
342 ipc_answer_0(rid, ENOENT);
343 goto out;
344 }
345
346 /* Miss in the last component */
347 if (lflag & (L_CREATE | L_LINK)) {
348 /* Request to create a new link */
349 if (!ops->is_directory(cur)) {
350 ipc_answer_0(rid, ENOTDIR);
351 goto out;
352 }
353
354 fs_node_t *fn;
355 if (lflag & L_CREATE)
356 rc = ops->create(&fn, dev_handle,
357 lflag);
358 else
359 rc = ops->node_get(&fn, dev_handle,
360 index);
361 on_error(rc, goto out_with_answer);
362
363 if (fn) {
364 rc = ops->link(cur, fn, component);
365 if (rc != EOK) {
366 if (lflag & L_CREATE)
367 (void) ops->destroy(fn);
368 ipc_answer_0(rid, rc);
369 } else {
370 ipc_answer_5(rid, EOK,
371 fs_handle, dev_handle,
372 ops->index_get(fn),
373 ops->size_get(fn),
374 ops->lnkcnt_get(fn));
375 (void) ops->node_put(fn);
376 }
377 } else
378 ipc_answer_0(rid, ENOSPC);
379
380 goto out;
381 }
382
383 ipc_answer_0(rid, ENOENT);
384 goto out;
385 }
386
387 if (par) {
388 rc = ops->node_put(par);
389 on_error(rc, goto out_with_answer);
390 }
391
392 /* Descend one level */
393 par = cur;
394 cur = tmp;
395 tmp = NULL;
396 }
397
398 /* Handle miss: excessive components */
399 if (next <= last) {
400 bool has_children;
401 rc = ops->has_children(&has_children, cur);
402 on_error(rc, goto out_with_answer);
403
404 if (has_children)
405 goto skip_miss;
406
407 if (lflag & (L_CREATE | L_LINK)) {
408 if (!ops->is_directory(cur)) {
409 ipc_answer_0(rid, ENOTDIR);
410 goto out;
411 }
412
413 /* Collect next component */
414 len = 0;
415 while (next <= last) {
416 if (ops->plb_get_char(next) == '/') {
417 /* More than one component */
418 ipc_answer_0(rid, ENOENT);
419 goto out;
420 }
421
422 if (len + 1 == NAME_MAX) {
423 /* Component length overflow */
424 ipc_answer_0(rid, ENAMETOOLONG);
425 goto out;
426 }
427
428 component[len++] = ops->plb_get_char(next);
429 /* Process next character */
430 next++;
431 }
432
433 assert(len);
434 component[len] = '\0';
435
436 fs_node_t *fn;
437 if (lflag & L_CREATE)
438 rc = ops->create(&fn, dev_handle, lflag);
439 else
440 rc = ops->node_get(&fn, dev_handle, index);
441 on_error(rc, goto out_with_answer);
442
443 if (fn) {
444 rc = ops->link(cur, fn, component);
445 if (rc != EOK) {
446 if (lflag & L_CREATE)
447 (void) ops->destroy(fn);
448 ipc_answer_0(rid, rc);
449 } else {
450 ipc_answer_5(rid, EOK,
451 fs_handle, dev_handle,
452 ops->index_get(fn),
453 ops->size_get(fn),
454 ops->lnkcnt_get(fn));
455 (void) ops->node_put(fn);
456 }
457 } else
458 ipc_answer_0(rid, ENOSPC);
459
460 goto out;
461 }
462
463 ipc_answer_0(rid, ENOENT);
464 goto out;
465 }
466
467skip_miss:
468
469 /* Handle hit */
470 if (lflag & L_UNLINK) {
471 unsigned int old_lnkcnt = ops->lnkcnt_get(cur);
472 rc = ops->unlink(par, cur, component);
473 ipc_answer_5(rid, (ipcarg_t) rc, fs_handle, dev_handle,
474 ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
475 goto out;
476 }
477
478 if (((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) ||
479 (lflag & L_LINK)) {
480 ipc_answer_0(rid, EEXIST);
481 goto out;
482 }
483
484 if ((lflag & L_FILE) && (ops->is_directory(cur))) {
485 ipc_answer_0(rid, EISDIR);
486 goto out;
487 }
488
489 if ((lflag & L_DIRECTORY) && (ops->is_file(cur))) {
490 ipc_answer_0(rid, ENOTDIR);
491 goto out;
492 }
493
494 if ((lflag & L_ROOT) && par) {
495 ipc_answer_0(rid, EINVAL);
496 goto out;
497 }
498
499out_with_answer:
500
501 if (rc == EOK) {
502 if (lflag & L_OPEN)
503 rc = ops->node_open(cur);
504
505 ipc_answer_5(rid, rc, fs_handle, dev_handle,
506 ops->index_get(cur), ops->size_get(cur),
507 ops->lnkcnt_get(cur));
508 } else
509 ipc_answer_0(rid, rc);
510
511out:
512
513 if (par)
514 (void) ops->node_put(par);
515
516 if (cur)
517 (void) ops->node_put(cur);
518
519 if (tmp)
520 (void) ops->node_put(tmp);
521}
522
523void libfs_stat(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
524 ipc_call_t *request)
525{
526 dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
527 fs_index_t index = (fs_index_t) IPC_GET_ARG2(*request);
528
529 fs_node_t *fn;
530 int rc = ops->node_get(&fn, dev_handle, index);
531 on_error(rc, answer_and_return(rid, rc));
532
533 ipc_callid_t callid;
534 size_t size;
535 if ((!async_data_read_receive(&callid, &size)) ||
536 (size != sizeof(struct stat))) {
537 ops->node_put(fn);
538 ipc_answer_0(callid, EINVAL);
539 ipc_answer_0(rid, EINVAL);
540 return;
541 }
542
543 struct stat stat;
544 memset(&stat, 0, sizeof(struct stat));
545
546 stat.fs_handle = fs_handle;
547 stat.dev_handle = dev_handle;
548 stat.index = index;
549 stat.lnkcnt = ops->lnkcnt_get(fn);
550 stat.is_file = ops->is_file(fn);
551 stat.is_directory = ops->is_directory(fn);
552 stat.size = ops->size_get(fn);
553 stat.device = ops->device_get(fn);
554
555 ops->node_put(fn);
556
557 async_data_read_finalize(callid, &stat, sizeof(struct stat));
558 ipc_answer_0(rid, EOK);
559}
560
561/** Open VFS triplet.
562 *
563 * @param ops libfs operations structure with function pointers to
564 * file system implementation
565 * @param rid Request ID of the VFS_OUT_OPEN_NODE request.
566 * @param request VFS_OUT_OPEN_NODE request data itself.
567 *
568 */
569void libfs_open_node(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
570 ipc_call_t *request)
571{
572 dev_handle_t dev_handle = IPC_GET_ARG1(*request);
573 fs_index_t index = IPC_GET_ARG2(*request);
574 fs_node_t *fn;
575 int rc;
576
577 rc = ops->node_get(&fn, dev_handle, index);
578 on_error(rc, answer_and_return(rid, rc));
579
580 if (fn == NULL) {
581 ipc_answer_0(rid, ENOENT);
582 return;
583 }
584
585 rc = ops->node_open(fn);
586 ipc_answer_3(rid, rc, ops->size_get(fn), ops->lnkcnt_get(fn),
587 (ops->is_file(fn) ? L_FILE : 0) | (ops->is_directory(fn) ? L_DIRECTORY : 0));
588
589 (void) ops->node_put(fn);
590}
591
592/** @}
593 */
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