Rev 3397 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
2689 | jermar | 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_ops.c |
||
35 | * @brief Operations that VFS offers to its clients. |
||
36 | */ |
||
37 | |||
2763 | jermar | 38 | #include "vfs.h" |
2689 | jermar | 39 | #include <ipc/ipc.h> |
40 | #include <async.h> |
||
41 | #include <errno.h> |
||
42 | #include <stdio.h> |
||
43 | #include <stdlib.h> |
||
44 | #include <string.h> |
||
45 | #include <bool.h> |
||
46 | #include <futex.h> |
||
47 | #include <rwlock.h> |
||
48 | #include <libadt/list.h> |
||
49 | #include <unistd.h> |
||
50 | #include <ctype.h> |
||
2708 | jermar | 51 | #include <fcntl.h> |
2689 | jermar | 52 | #include <assert.h> |
2763 | jermar | 53 | #include <vfs/canonify.h> |
2689 | jermar | 54 | |
2748 | jermar | 55 | /* Forward declarations of static functions. */ |
2770 | jermar | 56 | static int vfs_truncate_internal(fs_handle_t, dev_handle_t, fs_index_t, size_t); |
2748 | jermar | 57 | |
2689 | jermar | 58 | /** |
59 | * This rwlock prevents the race between a triplet-to-VFS-node resolution and a |
||
60 | * concurrent VFS operation which modifies the file system namespace. |
||
61 | */ |
||
62 | RWLOCK_INITIALIZE(namespace_rwlock); |
||
63 | |||
2766 | jermar | 64 | futex_t rootfs_futex = FUTEX_INITIALIZER; |
3109 | jermar | 65 | vfs_pair_t rootfs = { |
2689 | jermar | 66 | .fs_handle = 0, |
3109 | jermar | 67 | .dev_handle = 0 |
2689 | jermar | 68 | }; |
69 | |||
70 | void vfs_mount(ipc_callid_t rid, ipc_call_t *request) |
||
71 | { |
||
2770 | jermar | 72 | dev_handle_t dev_handle; |
2689 | jermar | 73 | vfs_node_t *mp_node = NULL; |
3255 | jermar | 74 | ipc_callid_t callid; |
75 | ipc_call_t data; |
||
2957 | jermar | 76 | int rc; |
2958 | jermar | 77 | int phone; |
3255 | jermar | 78 | size_t size; |
2689 | jermar | 79 | |
80 | /* |
||
81 | * We expect the library to do the device-name to device-handle |
||
82 | * translation for us, thus the device handle will arrive as ARG1 |
||
83 | * in the request. |
||
84 | */ |
||
2770 | jermar | 85 | dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
2689 | jermar | 86 | |
87 | /* |
||
88 | * For now, don't make use of ARG2 and ARG3, but they can be used to |
||
89 | * carry mount options in the future. |
||
90 | */ |
||
91 | |||
92 | /* |
||
93 | * Now, we expect the client to send us data with the name of the file |
||
94 | * system. |
||
95 | */ |
||
96 | if (!ipc_data_write_receive(&callid, &size)) { |
||
97 | ipc_answer_0(callid, EINVAL); |
||
98 | ipc_answer_0(rid, EINVAL); |
||
99 | return; |
||
100 | } |
||
101 | |||
102 | /* |
||
103 | * Don't receive more than is necessary for storing a full file system |
||
104 | * name. |
||
105 | */ |
||
106 | if (size < 1 || size > FS_NAME_MAXLEN) { |
||
107 | ipc_answer_0(callid, EINVAL); |
||
108 | ipc_answer_0(rid, EINVAL); |
||
109 | return; |
||
110 | } |
||
111 | |||
2707 | jermar | 112 | /* Deliver the file system name. */ |
2689 | jermar | 113 | char fs_name[FS_NAME_MAXLEN + 1]; |
114 | (void) ipc_data_write_finalize(callid, fs_name, size); |
||
115 | fs_name[size] = '\0'; |
||
116 | |||
117 | /* |
||
3255 | jermar | 118 | * Wait for IPC_M_PING so that we can return an error if we don't know |
119 | * fs_name. |
||
120 | */ |
||
121 | callid = async_get_call(&data); |
||
122 | if (IPC_GET_METHOD(data) != IPC_M_PING) { |
||
123 | ipc_answer_0(callid, ENOTSUP); |
||
124 | ipc_answer_0(rid, ENOTSUP); |
||
125 | return; |
||
126 | } |
||
127 | |||
128 | /* |
||
2689 | jermar | 129 | * Check if we know a file system with the same name as is in fs_name. |
130 | * This will also give us its file system handle. |
||
131 | */ |
||
2770 | jermar | 132 | fs_handle_t fs_handle = fs_name_to_handle(fs_name, true); |
2689 | jermar | 133 | if (!fs_handle) { |
3255 | jermar | 134 | ipc_answer_0(callid, ENOENT); |
2689 | jermar | 135 | ipc_answer_0(rid, ENOENT); |
136 | return; |
||
137 | } |
||
138 | |||
3255 | jermar | 139 | /* Acknowledge that we know fs_name. */ |
140 | ipc_answer_0(callid, EOK); |
||
141 | |||
2707 | jermar | 142 | /* Now, we want the client to send us the mount point. */ |
2689 | jermar | 143 | if (!ipc_data_write_receive(&callid, &size)) { |
144 | ipc_answer_0(callid, EINVAL); |
||
145 | ipc_answer_0(rid, EINVAL); |
||
146 | return; |
||
147 | } |
||
148 | |||
2707 | jermar | 149 | /* Check whether size is reasonable wrt. the mount point. */ |
2689 | jermar | 150 | if (size < 1 || size > MAX_PATH_LEN) { |
151 | ipc_answer_0(callid, EINVAL); |
||
152 | ipc_answer_0(rid, EINVAL); |
||
153 | return; |
||
154 | } |
||
2707 | jermar | 155 | /* Allocate buffer for the mount point data being received. */ |
3492 | rimsky | 156 | char *buf; |
2752 | jermar | 157 | buf = malloc(size + 1); |
2689 | jermar | 158 | if (!buf) { |
159 | ipc_answer_0(callid, ENOMEM); |
||
160 | ipc_answer_0(rid, ENOMEM); |
||
161 | return; |
||
162 | } |
||
163 | |||
2707 | jermar | 164 | /* Deliver the mount point. */ |
2689 | jermar | 165 | (void) ipc_data_write_finalize(callid, buf, size); |
2752 | jermar | 166 | buf[size] = '\0'; |
2689 | jermar | 167 | |
3109 | jermar | 168 | /* Resolve the path to the mountpoint. */ |
2691 | jermar | 169 | vfs_lookup_res_t mp_res; |
2689 | jermar | 170 | futex_down(&rootfs_futex); |
171 | if (rootfs.fs_handle) { |
||
2707 | jermar | 172 | /* We already have the root FS. */ |
2689 | jermar | 173 | rwlock_write_lock(&namespace_rwlock); |
2788 | jermar | 174 | if ((size == 1) && (buf[0] == '/')) { |
175 | /* Trying to mount root FS over root FS */ |
||
176 | rwlock_write_unlock(&namespace_rwlock); |
||
177 | futex_up(&rootfs_futex); |
||
178 | free(buf); |
||
179 | ipc_answer_0(rid, EBUSY); |
||
180 | return; |
||
181 | } |
||
2752 | jermar | 182 | rc = vfs_lookup_internal(buf, L_DIRECTORY, &mp_res, NULL); |
2689 | jermar | 183 | if (rc != EOK) { |
2707 | jermar | 184 | /* The lookup failed for some reason. */ |
2689 | jermar | 185 | rwlock_write_unlock(&namespace_rwlock); |
186 | futex_up(&rootfs_futex); |
||
187 | free(buf); |
||
188 | ipc_answer_0(rid, rc); |
||
189 | return; |
||
190 | } |
||
2691 | jermar | 191 | mp_node = vfs_node_get(&mp_res); |
2689 | jermar | 192 | if (!mp_node) { |
193 | rwlock_write_unlock(&namespace_rwlock); |
||
194 | futex_up(&rootfs_futex); |
||
195 | free(buf); |
||
196 | ipc_answer_0(rid, ENOMEM); |
||
197 | return; |
||
198 | } |
||
199 | /* |
||
200 | * Now we hold a reference to mp_node. |
||
201 | * It will be dropped upon the corresponding VFS_UNMOUNT. |
||
202 | * This prevents the mount point from being deleted. |
||
203 | */ |
||
204 | rwlock_write_unlock(&namespace_rwlock); |
||
205 | } else { |
||
2707 | jermar | 206 | /* We still don't have the root file system mounted. */ |
2689 | jermar | 207 | if ((size == 1) && (buf[0] == '/')) { |
3397 | rimsky | 208 | vfs_lookup_res_t mr_res; |
209 | vfs_node_t *mr_node; |
||
210 | ipcarg_t rindex; |
||
211 | ipcarg_t rsize; |
||
212 | ipcarg_t rlnkcnt; |
||
213 | |||
2958 | jermar | 214 | /* |
215 | * For this simple, but important case, |
||
216 | * we are almost done. |
||
217 | */ |
||
218 | free(buf); |
||
219 | |||
3109 | jermar | 220 | /* Tell the mountee that it is being mounted. */ |
221 | phone = vfs_grab_phone(fs_handle); |
||
3397 | rimsky | 222 | rc = async_req_1_3(phone, VFS_MOUNTED, |
223 | (ipcarg_t) dev_handle, &rindex, &rsize, &rlnkcnt); |
||
2958 | jermar | 224 | vfs_release_phone(phone); |
3397 | rimsky | 225 | |
226 | if (rc != EOK) { |
||
227 | futex_up(&rootfs_futex); |
||
228 | ipc_answer_0(rid, rc); |
||
229 | return; |
||
3109 | jermar | 230 | } |
2958 | jermar | 231 | |
3397 | rimsky | 232 | mr_res.triplet.fs_handle = fs_handle; |
233 | mr_res.triplet.dev_handle = dev_handle; |
||
234 | mr_res.triplet.index = (fs_index_t) rindex; |
||
235 | mr_res.size = (size_t) rsize; |
||
236 | mr_res.lnkcnt = (unsigned) rlnkcnt; |
||
237 | |||
238 | rootfs.fs_handle = fs_handle; |
||
239 | rootfs.dev_handle = dev_handle; |
||
2689 | jermar | 240 | futex_up(&rootfs_futex); |
3397 | rimsky | 241 | |
242 | /* Add reference to the mounted root. */ |
||
243 | mr_node = vfs_node_get(&mr_res); |
||
244 | assert(mr_node); |
||
245 | |||
2958 | jermar | 246 | ipc_answer_0(rid, rc); |
2689 | jermar | 247 | return; |
248 | } else { |
||
249 | /* |
||
250 | * We can't resolve this without the root filesystem |
||
251 | * being mounted first. |
||
252 | */ |
||
253 | futex_up(&rootfs_futex); |
||
254 | free(buf); |
||
255 | ipc_answer_0(rid, ENOENT); |
||
256 | return; |
||
257 | } |
||
258 | } |
||
259 | futex_up(&rootfs_futex); |
||
260 | |||
261 | free(buf); /* The buffer is not needed anymore. */ |
||
262 | |||
263 | /* |
||
264 | * At this point, we have all necessary pieces: file system and device |
||
3109 | jermar | 265 | * handles, and we know the mount point VFS node. |
2689 | jermar | 266 | */ |
267 | |||
2958 | jermar | 268 | phone = vfs_grab_phone(mp_res.triplet.fs_handle); |
3109 | jermar | 269 | rc = async_req_4_0(phone, VFS_MOUNT, |
2691 | jermar | 270 | (ipcarg_t) mp_res.triplet.dev_handle, |
2957 | jermar | 271 | (ipcarg_t) mp_res.triplet.index, |
3109 | jermar | 272 | (ipcarg_t) fs_handle, |
273 | (ipcarg_t) dev_handle); |
||
2689 | jermar | 274 | vfs_release_phone(phone); |
275 | |||
2957 | jermar | 276 | if (rc != EOK) { |
3109 | jermar | 277 | /* Mount failed, drop reference to mp_node. */ |
2689 | jermar | 278 | if (mp_node) |
279 | vfs_node_put(mp_node); |
||
280 | } |
||
281 | |||
2957 | jermar | 282 | ipc_answer_0(rid, rc); |
2689 | jermar | 283 | } |
284 | |||
285 | void vfs_open(ipc_callid_t rid, ipc_call_t *request) |
||
286 | { |
||
287 | if (!vfs_files_init()) { |
||
288 | ipc_answer_0(rid, ENOMEM); |
||
289 | return; |
||
290 | } |
||
291 | |||
292 | /* |
||
2700 | jermar | 293 | * The POSIX interface is open(path, oflag, mode). |
294 | * We can receive oflags and mode along with the VFS_OPEN call; the path |
||
2689 | jermar | 295 | * will need to arrive in another call. |
2700 | jermar | 296 | * |
297 | * We also receive one private, non-POSIX set of flags called lflag |
||
298 | * used to pass information to vfs_lookup_internal(). |
||
2689 | jermar | 299 | */ |
2700 | jermar | 300 | int lflag = IPC_GET_ARG1(*request); |
301 | int oflag = IPC_GET_ARG2(*request); |
||
302 | int mode = IPC_GET_ARG3(*request); |
||
2689 | jermar | 303 | size_t len; |
304 | |||
2708 | jermar | 305 | if (oflag & O_CREAT) |
306 | lflag |= L_CREATE; |
||
307 | if (oflag & O_EXCL) |
||
308 | lflag |= L_EXCLUSIVE; |
||
309 | |||
2689 | jermar | 310 | ipc_callid_t callid; |
311 | |||
312 | if (!ipc_data_write_receive(&callid, &len)) { |
||
313 | ipc_answer_0(callid, EINVAL); |
||
314 | ipc_answer_0(rid, EINVAL); |
||
315 | return; |
||
316 | } |
||
2752 | jermar | 317 | char *path = malloc(len + 1); |
2689 | jermar | 318 | if (!path) { |
319 | ipc_answer_0(callid, ENOMEM); |
||
320 | ipc_answer_0(rid, ENOMEM); |
||
321 | return; |
||
322 | } |
||
323 | int rc; |
||
324 | if ((rc = ipc_data_write_finalize(callid, path, len))) { |
||
325 | ipc_answer_0(rid, rc); |
||
326 | free(path); |
||
327 | return; |
||
328 | } |
||
2752 | jermar | 329 | path[len] = '\0'; |
2689 | jermar | 330 | |
331 | /* |
||
332 | * Avoid the race condition in which the file can be deleted before we |
||
333 | * find/create-and-lock the VFS node corresponding to the looked-up |
||
334 | * triplet. |
||
335 | */ |
||
2708 | jermar | 336 | if (lflag & L_CREATE) |
337 | rwlock_write_lock(&namespace_rwlock); |
||
338 | else |
||
339 | rwlock_read_lock(&namespace_rwlock); |
||
2689 | jermar | 340 | |
2707 | jermar | 341 | /* The path is now populated and we can call vfs_lookup_internal(). */ |
2691 | jermar | 342 | vfs_lookup_res_t lr; |
2752 | jermar | 343 | rc = vfs_lookup_internal(path, lflag, &lr, NULL); |
2689 | jermar | 344 | if (rc) { |
2708 | jermar | 345 | if (lflag & L_CREATE) |
346 | rwlock_write_unlock(&namespace_rwlock); |
||
347 | else |
||
348 | rwlock_read_unlock(&namespace_rwlock); |
||
2689 | jermar | 349 | ipc_answer_0(rid, rc); |
350 | free(path); |
||
351 | return; |
||
352 | } |
||
353 | |||
2748 | jermar | 354 | /* Path is no longer needed. */ |
2689 | jermar | 355 | free(path); |
356 | |||
2691 | jermar | 357 | vfs_node_t *node = vfs_node_get(&lr); |
2708 | jermar | 358 | if (lflag & L_CREATE) |
359 | rwlock_write_unlock(&namespace_rwlock); |
||
360 | else |
||
361 | rwlock_read_unlock(&namespace_rwlock); |
||
2689 | jermar | 362 | |
2748 | jermar | 363 | /* Truncate the file if requested and if necessary. */ |
364 | if (oflag & O_TRUNC) { |
||
2749 | jermar | 365 | rwlock_write_lock(&node->contents_rwlock); |
2748 | jermar | 366 | if (node->size) { |
367 | rc = vfs_truncate_internal(node->fs_handle, |
||
368 | node->dev_handle, node->index, 0); |
||
369 | if (rc) { |
||
2749 | jermar | 370 | rwlock_write_unlock(&node->contents_rwlock); |
2748 | jermar | 371 | vfs_node_put(node); |
372 | ipc_answer_0(rid, rc); |
||
373 | return; |
||
374 | } |
||
375 | node->size = 0; |
||
376 | } |
||
2749 | jermar | 377 | rwlock_write_unlock(&node->contents_rwlock); |
2748 | jermar | 378 | } |
379 | |||
2689 | jermar | 380 | /* |
381 | * Get ourselves a file descriptor and the corresponding vfs_file_t |
||
382 | * structure. |
||
383 | */ |
||
384 | int fd = vfs_fd_alloc(); |
||
385 | if (fd < 0) { |
||
386 | vfs_node_put(node); |
||
387 | ipc_answer_0(rid, fd); |
||
388 | return; |
||
389 | } |
||
390 | vfs_file_t *file = vfs_file_get(fd); |
||
391 | file->node = node; |
||
2710 | jermar | 392 | if (oflag & O_APPEND) |
2709 | jermar | 393 | file->append = true; |
2689 | jermar | 394 | |
395 | /* |
||
396 | * The following increase in reference count is for the fact that the |
||
397 | * file is being opened and that a file structure is pointing to it. |
||
398 | * It is necessary so that the file will not disappear when |
||
399 | * vfs_node_put() is called. The reference will be dropped by the |
||
400 | * respective VFS_CLOSE. |
||
401 | */ |
||
402 | vfs_node_addref(node); |
||
403 | vfs_node_put(node); |
||
404 | |||
2707 | jermar | 405 | /* Success! Return the new file descriptor to the client. */ |
2689 | jermar | 406 | ipc_answer_1(rid, EOK, fd); |
407 | } |
||
408 | |||
2734 | jermar | 409 | void vfs_close(ipc_callid_t rid, ipc_call_t *request) |
410 | { |
||
411 | int fd = IPC_GET_ARG1(*request); |
||
3215 | jermar | 412 | int rc = vfs_fd_free(fd); |
413 | ipc_answer_0(rid, rc); |
||
2734 | jermar | 414 | } |
415 | |||
2689 | jermar | 416 | static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read) |
417 | { |
||
418 | |||
419 | /* |
||
420 | * The following code strongly depends on the fact that the files data |
||
421 | * structure can be only accessed by a single fibril and all file |
||
422 | * operations are serialized (i.e. the reads and writes cannot |
||
423 | * interleave and a file cannot be closed while it is being read). |
||
424 | * |
||
425 | * Additional synchronization needs to be added once the table of |
||
426 | * open files supports parallel access! |
||
427 | */ |
||
428 | |||
429 | int fd = IPC_GET_ARG1(*request); |
||
3079 | decky | 430 | |
2707 | jermar | 431 | /* Lookup the file structure corresponding to the file descriptor. */ |
2689 | jermar | 432 | vfs_file_t *file = vfs_file_get(fd); |
433 | if (!file) { |
||
434 | ipc_answer_0(rid, ENOENT); |
||
435 | return; |
||
436 | } |
||
3079 | decky | 437 | |
2689 | jermar | 438 | /* |
439 | * Now we need to receive a call with client's |
||
440 | * IPC_M_DATA_READ/IPC_M_DATA_WRITE request. |
||
441 | */ |
||
442 | ipc_callid_t callid; |
||
443 | int res; |
||
444 | if (read) |
||
445 | res = ipc_data_read_receive(&callid, NULL); |
||
446 | else |
||
447 | res = ipc_data_write_receive(&callid, NULL); |
||
448 | if (!res) { |
||
449 | ipc_answer_0(callid, EINVAL); |
||
450 | ipc_answer_0(rid, EINVAL); |
||
451 | return; |
||
452 | } |
||
3079 | decky | 453 | |
2689 | jermar | 454 | /* |
455 | * Lock the open file structure so that no other thread can manipulate |
||
456 | * the same open file at a time. |
||
457 | */ |
||
458 | futex_down(&file->lock); |
||
3079 | decky | 459 | |
2689 | jermar | 460 | /* |
461 | * Lock the file's node so that no other client can read/write to it at |
||
462 | * the same time. |
||
463 | */ |
||
464 | if (read) |
||
465 | rwlock_read_lock(&file->node->contents_rwlock); |
||
466 | else |
||
467 | rwlock_write_lock(&file->node->contents_rwlock); |
||
3079 | decky | 468 | |
2689 | jermar | 469 | int fs_phone = vfs_grab_phone(file->node->fs_handle); |
470 | |||
2707 | jermar | 471 | /* Make a VFS_READ/VFS_WRITE request at the destination FS server. */ |
2689 | jermar | 472 | aid_t msg; |
473 | ipc_call_t answer; |
||
2709 | jermar | 474 | if (!read && file->append) |
475 | file->pos = file->node->size; |
||
2689 | jermar | 476 | msg = async_send_3(fs_phone, IPC_GET_METHOD(*request), |
477 | file->node->dev_handle, file->node->index, file->pos, &answer); |
||
478 | |||
479 | /* |
||
480 | * Forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the |
||
481 | * destination FS server. The call will be routed as if sent by |
||
482 | * ourselves. Note that call arguments are immutable in this case so we |
||
483 | * don't have to bother. |
||
484 | */ |
||
485 | ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME); |
||
3079 | decky | 486 | |
2689 | jermar | 487 | vfs_release_phone(fs_phone); |
3079 | decky | 488 | |
2707 | jermar | 489 | /* Wait for reply from the FS server. */ |
2689 | jermar | 490 | ipcarg_t rc; |
491 | async_wait_for(msg, &rc); |
||
492 | size_t bytes = IPC_GET_ARG1(answer); |
||
3079 | decky | 493 | |
2707 | jermar | 494 | /* Unlock the VFS node. */ |
2689 | jermar | 495 | if (read) |
496 | rwlock_read_unlock(&file->node->contents_rwlock); |
||
497 | else { |
||
498 | /* Update the cached version of node's size. */ |
||
2710 | jermar | 499 | if (rc == EOK) |
500 | file->node->size = IPC_GET_ARG2(answer); |
||
2689 | jermar | 501 | rwlock_write_unlock(&file->node->contents_rwlock); |
502 | } |
||
3079 | decky | 503 | |
2707 | jermar | 504 | /* Update the position pointer and unlock the open file. */ |
2710 | jermar | 505 | if (rc == EOK) |
506 | file->pos += bytes; |
||
2689 | jermar | 507 | futex_up(&file->lock); |
3079 | decky | 508 | |
2689 | jermar | 509 | /* |
510 | * FS server's reply is the final result of the whole operation we |
||
511 | * return to the client. |
||
512 | */ |
||
513 | ipc_answer_1(rid, rc, bytes); |
||
514 | } |
||
515 | |||
516 | void vfs_read(ipc_callid_t rid, ipc_call_t *request) |
||
517 | { |
||
518 | vfs_rdwr(rid, request, true); |
||
519 | } |
||
520 | |||
521 | void vfs_write(ipc_callid_t rid, ipc_call_t *request) |
||
522 | { |
||
523 | vfs_rdwr(rid, request, false); |
||
524 | } |
||
525 | |||
526 | void vfs_seek(ipc_callid_t rid, ipc_call_t *request) |
||
527 | { |
||
528 | int fd = (int) IPC_GET_ARG1(*request); |
||
529 | off_t off = (off_t) IPC_GET_ARG2(*request); |
||
530 | int whence = (int) IPC_GET_ARG3(*request); |
||
531 | |||
532 | |||
2707 | jermar | 533 | /* Lookup the file structure corresponding to the file descriptor. */ |
2689 | jermar | 534 | vfs_file_t *file = vfs_file_get(fd); |
535 | if (!file) { |
||
536 | ipc_answer_0(rid, ENOENT); |
||
537 | return; |
||
538 | } |
||
539 | |||
540 | off_t newpos; |
||
541 | futex_down(&file->lock); |
||
542 | if (whence == SEEK_SET) { |
||
543 | file->pos = off; |
||
544 | futex_up(&file->lock); |
||
545 | ipc_answer_1(rid, EOK, off); |
||
546 | return; |
||
547 | } |
||
548 | if (whence == SEEK_CUR) { |
||
549 | if (file->pos + off < file->pos) { |
||
550 | futex_up(&file->lock); |
||
551 | ipc_answer_0(rid, EOVERFLOW); |
||
552 | return; |
||
553 | } |
||
554 | file->pos += off; |
||
555 | newpos = file->pos; |
||
556 | futex_up(&file->lock); |
||
557 | ipc_answer_1(rid, EOK, newpos); |
||
558 | return; |
||
559 | } |
||
560 | if (whence == SEEK_END) { |
||
561 | rwlock_read_lock(&file->node->contents_rwlock); |
||
562 | size_t size = file->node->size; |
||
563 | rwlock_read_unlock(&file->node->contents_rwlock); |
||
564 | if (size + off < size) { |
||
565 | futex_up(&file->lock); |
||
566 | ipc_answer_0(rid, EOVERFLOW); |
||
567 | return; |
||
568 | } |
||
569 | newpos = size + off; |
||
570 | futex_up(&file->lock); |
||
571 | ipc_answer_1(rid, EOK, newpos); |
||
572 | return; |
||
573 | } |
||
574 | futex_up(&file->lock); |
||
575 | ipc_answer_0(rid, EINVAL); |
||
576 | } |
||
577 | |||
2770 | jermar | 578 | int |
579 | vfs_truncate_internal(fs_handle_t fs_handle, dev_handle_t dev_handle, |
||
580 | fs_index_t index, size_t size) |
||
2748 | jermar | 581 | { |
582 | ipcarg_t rc; |
||
583 | int fs_phone; |
||
584 | |||
585 | fs_phone = vfs_grab_phone(fs_handle); |
||
586 | rc = async_req_3_0(fs_phone, VFS_TRUNCATE, (ipcarg_t)dev_handle, |
||
587 | (ipcarg_t)index, (ipcarg_t)size); |
||
588 | vfs_release_phone(fs_phone); |
||
589 | return (int)rc; |
||
590 | } |
||
591 | |||
2693 | jermar | 592 | void vfs_truncate(ipc_callid_t rid, ipc_call_t *request) |
593 | { |
||
594 | int fd = IPC_GET_ARG1(*request); |
||
595 | size_t size = IPC_GET_ARG2(*request); |
||
2748 | jermar | 596 | int rc; |
2693 | jermar | 597 | |
598 | vfs_file_t *file = vfs_file_get(fd); |
||
599 | if (!file) { |
||
600 | ipc_answer_0(rid, ENOENT); |
||
601 | return; |
||
602 | } |
||
603 | futex_down(&file->lock); |
||
604 | |||
605 | rwlock_write_lock(&file->node->contents_rwlock); |
||
2748 | jermar | 606 | rc = vfs_truncate_internal(file->node->fs_handle, |
607 | file->node->dev_handle, file->node->index, size); |
||
2693 | jermar | 608 | if (rc == EOK) |
609 | file->node->size = size; |
||
610 | rwlock_write_unlock(&file->node->contents_rwlock); |
||
611 | |||
612 | futex_up(&file->lock); |
||
2748 | jermar | 613 | ipc_answer_0(rid, (ipcarg_t)rc); |
2693 | jermar | 614 | } |
615 | |||
2707 | jermar | 616 | void vfs_mkdir(ipc_callid_t rid, ipc_call_t *request) |
617 | { |
||
618 | int mode = IPC_GET_ARG1(*request); |
||
2735 | jermar | 619 | |
2707 | jermar | 620 | size_t len; |
621 | ipc_callid_t callid; |
||
622 | |||
623 | if (!ipc_data_write_receive(&callid, &len)) { |
||
624 | ipc_answer_0(callid, EINVAL); |
||
625 | ipc_answer_0(rid, EINVAL); |
||
626 | return; |
||
627 | } |
||
2752 | jermar | 628 | char *path = malloc(len + 1); |
2707 | jermar | 629 | if (!path) { |
630 | ipc_answer_0(callid, ENOMEM); |
||
631 | ipc_answer_0(rid, ENOMEM); |
||
632 | return; |
||
633 | } |
||
634 | int rc; |
||
635 | if ((rc = ipc_data_write_finalize(callid, path, len))) { |
||
636 | ipc_answer_0(rid, rc); |
||
637 | free(path); |
||
638 | return; |
||
639 | } |
||
2752 | jermar | 640 | path[len] = '\0'; |
2707 | jermar | 641 | |
642 | rwlock_write_lock(&namespace_rwlock); |
||
643 | int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE; |
||
2752 | jermar | 644 | rc = vfs_lookup_internal(path, lflag, NULL, NULL); |
2707 | jermar | 645 | rwlock_write_unlock(&namespace_rwlock); |
646 | free(path); |
||
647 | ipc_answer_0(rid, rc); |
||
648 | } |
||
649 | |||
2735 | jermar | 650 | void vfs_unlink(ipc_callid_t rid, ipc_call_t *request) |
651 | { |
||
652 | int lflag = IPC_GET_ARG1(*request); |
||
653 | |||
654 | size_t len; |
||
655 | ipc_callid_t callid; |
||
656 | |||
657 | if (!ipc_data_write_receive(&callid, &len)) { |
||
658 | ipc_answer_0(callid, EINVAL); |
||
659 | ipc_answer_0(rid, EINVAL); |
||
660 | return; |
||
661 | } |
||
2752 | jermar | 662 | char *path = malloc(len + 1); |
2735 | jermar | 663 | if (!path) { |
664 | ipc_answer_0(callid, ENOMEM); |
||
665 | ipc_answer_0(rid, ENOMEM); |
||
666 | return; |
||
667 | } |
||
668 | int rc; |
||
669 | if ((rc = ipc_data_write_finalize(callid, path, len))) { |
||
670 | ipc_answer_0(rid, rc); |
||
671 | free(path); |
||
672 | return; |
||
673 | } |
||
2752 | jermar | 674 | path[len] = '\0'; |
2735 | jermar | 675 | |
676 | rwlock_write_lock(&namespace_rwlock); |
||
677 | lflag &= L_DIRECTORY; /* sanitize lflag */ |
||
678 | vfs_lookup_res_t lr; |
||
2763 | jermar | 679 | rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL); |
2735 | jermar | 680 | free(path); |
681 | if (rc != EOK) { |
||
682 | rwlock_write_unlock(&namespace_rwlock); |
||
683 | ipc_answer_0(rid, rc); |
||
684 | return; |
||
685 | } |
||
686 | |||
687 | /* |
||
688 | * The name has already been unlinked by vfs_lookup_internal(). |
||
689 | * We have to get and put the VFS node to ensure that it is |
||
2742 | jermar | 690 | * VFS_DESTROY'ed after the last reference to it is dropped. |
2735 | jermar | 691 | */ |
692 | vfs_node_t *node = vfs_node_get(&lr); |
||
2766 | jermar | 693 | futex_down(&nodes_futex); |
2735 | jermar | 694 | node->lnkcnt--; |
2766 | jermar | 695 | futex_up(&nodes_futex); |
2735 | jermar | 696 | rwlock_write_unlock(&namespace_rwlock); |
697 | vfs_node_put(node); |
||
698 | ipc_answer_0(rid, EOK); |
||
699 | } |
||
700 | |||
2763 | jermar | 701 | void vfs_rename(ipc_callid_t rid, ipc_call_t *request) |
702 | { |
||
703 | size_t len; |
||
704 | ipc_callid_t callid; |
||
705 | int rc; |
||
706 | |||
707 | /* Retrieve the old path. */ |
||
708 | if (!ipc_data_write_receive(&callid, &len)) { |
||
709 | ipc_answer_0(callid, EINVAL); |
||
710 | ipc_answer_0(rid, EINVAL); |
||
711 | return; |
||
712 | } |
||
713 | char *old = malloc(len + 1); |
||
714 | if (!old) { |
||
715 | ipc_answer_0(callid, ENOMEM); |
||
716 | ipc_answer_0(rid, ENOMEM); |
||
717 | return; |
||
718 | } |
||
719 | if ((rc = ipc_data_write_finalize(callid, old, len))) { |
||
720 | ipc_answer_0(rid, rc); |
||
721 | free(old); |
||
722 | return; |
||
723 | } |
||
724 | old[len] = '\0'; |
||
725 | |||
726 | /* Retrieve the new path. */ |
||
727 | if (!ipc_data_write_receive(&callid, &len)) { |
||
728 | ipc_answer_0(callid, EINVAL); |
||
729 | ipc_answer_0(rid, EINVAL); |
||
730 | free(old); |
||
731 | return; |
||
732 | } |
||
733 | char *new = malloc(len + 1); |
||
734 | if (!new) { |
||
735 | ipc_answer_0(callid, ENOMEM); |
||
736 | ipc_answer_0(rid, ENOMEM); |
||
737 | free(old); |
||
738 | return; |
||
739 | } |
||
740 | if ((rc = ipc_data_write_finalize(callid, new, len))) { |
||
741 | ipc_answer_0(rid, rc); |
||
742 | free(old); |
||
743 | free(new); |
||
744 | return; |
||
745 | } |
||
746 | new[len] = '\0'; |
||
747 | |||
748 | char *oldc = canonify(old, &len); |
||
749 | char *newc = canonify(new, NULL); |
||
750 | if (!oldc || !newc) { |
||
751 | ipc_answer_0(rid, EINVAL); |
||
752 | free(old); |
||
753 | free(new); |
||
754 | return; |
||
755 | } |
||
756 | if (!strncmp(newc, oldc, len)) { |
||
757 | /* oldc is a prefix of newc */ |
||
758 | ipc_answer_0(rid, EINVAL); |
||
759 | free(old); |
||
760 | free(new); |
||
761 | return; |
||
762 | } |
||
763 | |||
764 | vfs_lookup_res_t old_lr; |
||
765 | vfs_lookup_res_t new_lr; |
||
766 | vfs_lookup_res_t new_par_lr; |
||
767 | rwlock_write_lock(&namespace_rwlock); |
||
768 | /* Lookup the node belonging to the old file name. */ |
||
769 | rc = vfs_lookup_internal(oldc, L_NONE, &old_lr, NULL); |
||
770 | if (rc != EOK) { |
||
771 | rwlock_write_unlock(&namespace_rwlock); |
||
772 | ipc_answer_0(rid, rc); |
||
773 | free(old); |
||
774 | free(new); |
||
775 | return; |
||
776 | } |
||
777 | vfs_node_t *old_node = vfs_node_get(&old_lr); |
||
778 | if (!old_node) { |
||
779 | rwlock_write_unlock(&namespace_rwlock); |
||
780 | ipc_answer_0(rid, ENOMEM); |
||
781 | free(old); |
||
782 | free(new); |
||
783 | return; |
||
784 | } |
||
785 | /* Lookup parent of the new file name. */ |
||
786 | rc = vfs_lookup_internal(newc, L_PARENT, &new_par_lr, NULL); |
||
787 | if (rc != EOK) { |
||
788 | rwlock_write_unlock(&namespace_rwlock); |
||
789 | ipc_answer_0(rid, rc); |
||
790 | free(old); |
||
791 | free(new); |
||
792 | return; |
||
793 | } |
||
794 | /* Check whether linking to the same file system instance. */ |
||
795 | if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) || |
||
796 | (old_node->dev_handle != new_par_lr.triplet.dev_handle)) { |
||
797 | rwlock_write_unlock(&namespace_rwlock); |
||
798 | ipc_answer_0(rid, EXDEV); /* different file systems */ |
||
799 | free(old); |
||
800 | free(new); |
||
801 | return; |
||
802 | } |
||
803 | /* Destroy the old link for the new name. */ |
||
804 | vfs_node_t *new_node = NULL; |
||
805 | rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL); |
||
806 | switch (rc) { |
||
807 | case ENOENT: |
||
808 | /* simply not in our way */ |
||
809 | break; |
||
810 | case EOK: |
||
811 | new_node = vfs_node_get(&new_lr); |
||
812 | if (!new_node) { |
||
813 | rwlock_write_unlock(&namespace_rwlock); |
||
814 | ipc_answer_0(rid, ENOMEM); |
||
815 | free(old); |
||
816 | free(new); |
||
817 | return; |
||
818 | } |
||
2766 | jermar | 819 | futex_down(&nodes_futex); |
2763 | jermar | 820 | new_node->lnkcnt--; |
2766 | jermar | 821 | futex_up(&nodes_futex); |
2763 | jermar | 822 | break; |
823 | default: |
||
824 | rwlock_write_unlock(&namespace_rwlock); |
||
825 | ipc_answer_0(rid, ENOTEMPTY); |
||
826 | free(old); |
||
827 | free(new); |
||
828 | return; |
||
829 | } |
||
830 | /* Create the new link for the new name. */ |
||
831 | rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index); |
||
832 | if (rc != EOK) { |
||
833 | rwlock_write_unlock(&namespace_rwlock); |
||
834 | if (new_node) |
||
835 | vfs_node_put(new_node); |
||
836 | ipc_answer_0(rid, rc); |
||
837 | free(old); |
||
838 | free(new); |
||
839 | return; |
||
840 | } |
||
2766 | jermar | 841 | futex_down(&nodes_futex); |
2763 | jermar | 842 | old_node->lnkcnt++; |
2766 | jermar | 843 | futex_up(&nodes_futex); |
2763 | jermar | 844 | /* Destroy the link for the old name. */ |
845 | rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL); |
||
846 | if (rc != EOK) { |
||
847 | rwlock_write_unlock(&namespace_rwlock); |
||
848 | vfs_node_put(old_node); |
||
849 | if (new_node) |
||
850 | vfs_node_put(new_node); |
||
851 | ipc_answer_0(rid, rc); |
||
852 | free(old); |
||
853 | free(new); |
||
854 | return; |
||
855 | } |
||
2766 | jermar | 856 | futex_down(&nodes_futex); |
2763 | jermar | 857 | old_node->lnkcnt--; |
2766 | jermar | 858 | futex_up(&nodes_futex); |
2763 | jermar | 859 | rwlock_write_unlock(&namespace_rwlock); |
860 | vfs_node_put(old_node); |
||
861 | if (new_node) |
||
862 | vfs_node_put(new_node); |
||
863 | free(old); |
||
864 | free(new); |
||
865 | ipc_answer_0(rid, EOK); |
||
866 | } |
||
867 | |||
2689 | jermar | 868 | /** |
869 | * @} |
||
870 | */ |