Rev 3513 | Rev 3519 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
2627 | jermar | 1 | /* |
2793 | jermar | 2 | * Copyright (c) 2008 Jakub Jermar |
2627 | 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 fat_ops.c |
||
35 | * @brief Implementation of VFS operations for the FAT file system server. |
||
36 | */ |
||
37 | |||
38 | #include "fat.h" |
||
3505 | jermar | 39 | #include "fat_dentry.h" |
40 | #include "fat_fat.h" |
||
2638 | jermar | 41 | #include "../../vfs/vfs.h" |
2793 | jermar | 42 | #include <libfs.h> |
2627 | jermar | 43 | #include <ipc/ipc.h> |
3257 | jermar | 44 | #include <ipc/services.h> |
45 | #include <ipc/devmap.h> |
||
2627 | jermar | 46 | #include <async.h> |
47 | #include <errno.h> |
||
2793 | jermar | 48 | #include <string.h> |
2798 | jermar | 49 | #include <byteorder.h> |
2831 | jermar | 50 | #include <libadt/hash_table.h> |
51 | #include <libadt/list.h> |
||
52 | #include <assert.h> |
||
2856 | jermar | 53 | #include <futex.h> |
3257 | jermar | 54 | #include <sys/mman.h> |
3499 | jermar | 55 | #include <align.h> |
2627 | jermar | 56 | |
2951 | jermar | 57 | /** Futex protecting the list of cached free FAT nodes. */ |
58 | static futex_t ffn_futex = FUTEX_INITIALIZER; |
||
2843 | jermar | 59 | |
2951 | jermar | 60 | /** List of cached free FAT nodes. */ |
61 | static LIST_INITIALIZE(ffn_head); |
||
62 | |||
3257 | jermar | 63 | static int dev_phone = -1; /* FIXME */ |
64 | static void *dev_buffer = NULL; /* FIXME */ |
||
65 | |||
3506 | jermar | 66 | block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs) |
2793 | jermar | 67 | { |
3257 | jermar | 68 | /* FIXME */ |
69 | block_t *b; |
||
70 | off_t bufpos = 0; |
||
71 | size_t buflen = 0; |
||
3272 | jermar | 72 | off_t pos = offset * bs; |
3257 | jermar | 73 | |
74 | assert(dev_phone != -1); |
||
75 | assert(dev_buffer); |
||
76 | |||
77 | b = malloc(sizeof(block_t)); |
||
78 | if (!b) |
||
79 | return NULL; |
||
80 | |||
81 | b->data = malloc(bs); |
||
82 | if (!b->data) { |
||
83 | free(b); |
||
84 | return NULL; |
||
85 | } |
||
86 | b->size = bs; |
||
87 | |||
3272 | jermar | 88 | if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos, |
3257 | jermar | 89 | b->data, bs, bs)) { |
90 | free(b->data); |
||
91 | free(b); |
||
92 | return NULL; |
||
93 | } |
||
94 | |||
95 | return b; |
||
2793 | jermar | 96 | } |
97 | |||
3506 | jermar | 98 | void block_put(block_t *block) |
2793 | jermar | 99 | { |
3257 | jermar | 100 | /* FIXME */ |
101 | free(block->data); |
||
102 | free(block); |
||
2793 | jermar | 103 | } |
104 | |||
2831 | jermar | 105 | static void fat_node_initialize(fat_node_t *node) |
2793 | jermar | 106 | { |
2951 | jermar | 107 | futex_initialize(&node->lock, 1); |
2864 | jermar | 108 | node->idx = NULL; |
2831 | jermar | 109 | node->type = 0; |
110 | link_initialize(&node->ffn_link); |
||
111 | node->size = 0; |
||
112 | node->lnkcnt = 0; |
||
113 | node->refcnt = 0; |
||
114 | node->dirty = false; |
||
2793 | jermar | 115 | } |
116 | |||
2893 | jermar | 117 | static void fat_node_sync(fat_node_t *node) |
2831 | jermar | 118 | { |
119 | /* TODO */ |
||
120 | } |
||
121 | |||
2951 | jermar | 122 | /** Internal version of fat_node_get(). |
123 | * |
||
124 | * @param idxp Locked index structure. |
||
125 | */ |
||
126 | static void *fat_node_get_core(fat_idx_t *idxp) |
||
2831 | jermar | 127 | { |
3516 | jermar | 128 | block_t *bb, *b; |
2891 | jermar | 129 | fat_dentry_t *d; |
3312 | jermar | 130 | fat_node_t *nodep = NULL; |
2891 | jermar | 131 | unsigned bps; |
132 | unsigned dps; |
||
133 | |||
2951 | jermar | 134 | if (idxp->nodep) { |
2891 | jermar | 135 | /* |
136 | * We are lucky. |
||
137 | * The node is already instantiated in memory. |
||
138 | */ |
||
2951 | jermar | 139 | futex_down(&idxp->nodep->lock); |
140 | if (!idxp->nodep->refcnt++) |
||
3312 | jermar | 141 | list_remove(&idxp->nodep->ffn_link); |
2951 | jermar | 142 | futex_up(&idxp->nodep->lock); |
143 | return idxp->nodep; |
||
2891 | jermar | 144 | } |
145 | |||
146 | /* |
||
147 | * We must instantiate the node from the file system. |
||
148 | */ |
||
149 | |||
2951 | jermar | 150 | assert(idxp->pfc); |
2891 | jermar | 151 | |
2951 | jermar | 152 | futex_down(&ffn_futex); |
2893 | jermar | 153 | if (!list_empty(&ffn_head)) { |
2951 | jermar | 154 | /* Try to use a cached free node structure. */ |
155 | fat_idx_t *idxp_tmp; |
||
2893 | jermar | 156 | nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
2951 | jermar | 157 | if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
158 | goto skip_cache; |
||
159 | idxp_tmp = nodep->idx; |
||
160 | if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
||
161 | futex_up(&nodep->lock); |
||
162 | goto skip_cache; |
||
163 | } |
||
164 | list_remove(&nodep->ffn_link); |
||
165 | futex_up(&ffn_futex); |
||
2893 | jermar | 166 | if (nodep->dirty) |
167 | fat_node_sync(nodep); |
||
2951 | jermar | 168 | idxp_tmp->nodep = NULL; |
169 | futex_up(&nodep->lock); |
||
170 | futex_up(&idxp_tmp->lock); |
||
2893 | jermar | 171 | } else { |
2951 | jermar | 172 | skip_cache: |
2893 | jermar | 173 | /* Try to allocate a new node structure. */ |
2951 | jermar | 174 | futex_up(&ffn_futex); |
2893 | jermar | 175 | nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
176 | if (!nodep) |
||
177 | return NULL; |
||
178 | } |
||
2891 | jermar | 179 | fat_node_initialize(nodep); |
180 | |||
3516 | jermar | 181 | bb = block_get(idxp->dev_handle, BS_BLOCK, BS_SIZE); |
182 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
2891 | jermar | 183 | dps = bps / sizeof(fat_dentry_t); |
184 | |||
2893 | jermar | 185 | /* Read the block that contains the dentry of interest. */ |
3516 | jermar | 186 | b = _fat_block_get(bb->data, idxp->dev_handle, idxp->pfc, |
2951 | jermar | 187 | (idxp->pdi * sizeof(fat_dentry_t)) / bps); |
2891 | jermar | 188 | assert(b); |
189 | |||
2951 | jermar | 190 | d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps); |
2893 | jermar | 191 | if (d->attr & FAT_ATTR_SUBDIR) { |
192 | /* |
||
193 | * The only directory which does not have this bit set is the |
||
194 | * root directory itself. The root directory node is handled |
||
195 | * and initialized elsewhere. |
||
196 | */ |
||
197 | nodep->type = FAT_DIRECTORY; |
||
3282 | jermar | 198 | /* |
3325 | jermar | 199 | * Unfortunately, the 'size' field of the FAT dentry is not |
200 | * defined for the directory entry type. We must determine the |
||
201 | * size of the directory by walking the FAT. |
||
3282 | jermar | 202 | */ |
3516 | jermar | 203 | nodep->size = bps * _fat_blcks_get(bb->data, idxp->dev_handle, |
3513 | jermar | 204 | uint16_t_le2host(d->firstc), NULL); |
2893 | jermar | 205 | } else { |
206 | nodep->type = FAT_FILE; |
||
3282 | jermar | 207 | nodep->size = uint32_t_le2host(d->size); |
2893 | jermar | 208 | } |
209 | nodep->firstc = uint16_t_le2host(d->firstc); |
||
210 | nodep->lnkcnt = 1; |
||
211 | nodep->refcnt = 1; |
||
212 | |||
213 | block_put(b); |
||
3516 | jermar | 214 | block_put(bb); |
2893 | jermar | 215 | |
216 | /* Link the idx structure with the node structure. */ |
||
2951 | jermar | 217 | nodep->idx = idxp; |
218 | idxp->nodep = nodep; |
||
2893 | jermar | 219 | |
220 | return nodep; |
||
2831 | jermar | 221 | } |
222 | |||
2951 | jermar | 223 | /** Instantiate a FAT in-core node. */ |
224 | static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
||
225 | { |
||
226 | void *node; |
||
227 | fat_idx_t *idxp; |
||
228 | |||
229 | idxp = fat_idx_get_by_index(dev_handle, index); |
||
230 | if (!idxp) |
||
231 | return NULL; |
||
232 | /* idxp->lock held */ |
||
233 | node = fat_node_get_core(idxp); |
||
234 | futex_up(&idxp->lock); |
||
235 | return node; |
||
236 | } |
||
237 | |||
2852 | jermar | 238 | static void fat_node_put(void *node) |
239 | { |
||
2910 | jermar | 240 | fat_node_t *nodep = (fat_node_t *)node; |
241 | |||
2951 | jermar | 242 | futex_down(&nodep->lock); |
2910 | jermar | 243 | if (!--nodep->refcnt) { |
2951 | jermar | 244 | futex_down(&ffn_futex); |
2910 | jermar | 245 | list_append(&nodep->ffn_link, &ffn_head); |
2951 | jermar | 246 | futex_up(&ffn_futex); |
2910 | jermar | 247 | } |
2951 | jermar | 248 | futex_up(&nodep->lock); |
2852 | jermar | 249 | } |
250 | |||
2857 | jermar | 251 | static void *fat_create(int flags) |
252 | { |
||
253 | return NULL; /* not supported at the moment */ |
||
254 | } |
||
255 | |||
2858 | jermar | 256 | static int fat_destroy(void *node) |
2857 | jermar | 257 | { |
2858 | jermar | 258 | return ENOTSUP; /* not supported at the moment */ |
2857 | jermar | 259 | } |
260 | |||
261 | static bool fat_link(void *prnt, void *chld, const char *name) |
||
262 | { |
||
263 | return false; /* not supported at the moment */ |
||
264 | } |
||
265 | |||
266 | static int fat_unlink(void *prnt, void *chld) |
||
267 | { |
||
268 | return ENOTSUP; /* not supported at the moment */ |
||
269 | } |
||
270 | |||
2793 | jermar | 271 | static void *fat_match(void *prnt, const char *component) |
272 | { |
||
273 | fat_node_t *parentp = (fat_node_t *)prnt; |
||
274 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
2822 | jermar | 275 | unsigned i, j; |
2828 | jermar | 276 | unsigned bps; /* bytes per sector */ |
2822 | jermar | 277 | unsigned dps; /* dentries per sector */ |
278 | unsigned blocks; |
||
2793 | jermar | 279 | fat_dentry_t *d; |
3516 | jermar | 280 | block_t *bb, *b; |
2793 | jermar | 281 | |
2953 | jermar | 282 | futex_down(&parentp->idx->lock); |
3516 | jermar | 283 | bb = block_get(parentp->idx->dev_handle, BS_BLOCK, BS_SIZE); |
284 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
2828 | jermar | 285 | dps = bps / sizeof(fat_dentry_t); |
286 | blocks = parentp->size / bps + (parentp->size % bps != 0); |
||
2822 | jermar | 287 | for (i = 0; i < blocks; i++) { |
288 | unsigned dentries; |
||
2793 | jermar | 289 | |
3516 | jermar | 290 | b = fat_block_get(bb->data, parentp, i); |
2822 | jermar | 291 | dentries = (i == blocks - 1) ? |
292 | parentp->size % sizeof(fat_dentry_t) : |
||
293 | dps; |
||
294 | for (j = 0; j < dentries; j++) { |
||
295 | d = ((fat_dentry_t *)b->data) + j; |
||
2845 | jermar | 296 | switch (fat_classify_dentry(d)) { |
297 | case FAT_DENTRY_SKIP: |
||
2822 | jermar | 298 | continue; |
2845 | jermar | 299 | case FAT_DENTRY_LAST: |
2822 | jermar | 300 | block_put(b); |
3516 | jermar | 301 | block_put(bb); |
2953 | jermar | 302 | futex_up(&parentp->idx->lock); |
2822 | jermar | 303 | return NULL; |
2845 | jermar | 304 | default: |
305 | case FAT_DENTRY_VALID: |
||
306 | dentry_name_canonify(d, name); |
||
307 | break; |
||
2822 | jermar | 308 | } |
3272 | jermar | 309 | if (stricmp(name, component) == 0) { |
2822 | jermar | 310 | /* hit */ |
2951 | jermar | 311 | void *node; |
2953 | jermar | 312 | /* |
313 | * Assume tree hierarchy for locking. We |
||
314 | * already have the parent and now we are going |
||
315 | * to lock the child. Never lock in the oposite |
||
316 | * order. |
||
317 | */ |
||
2890 | jermar | 318 | fat_idx_t *idx = fat_idx_get_by_pos( |
2881 | jermar | 319 | parentp->idx->dev_handle, parentp->firstc, |
2864 | jermar | 320 | i * dps + j); |
2953 | jermar | 321 | futex_up(&parentp->idx->lock); |
2890 | jermar | 322 | if (!idx) { |
323 | /* |
||
324 | * Can happen if memory is low or if we |
||
325 | * run out of 32-bit indices. |
||
326 | */ |
||
327 | block_put(b); |
||
3516 | jermar | 328 | block_put(bb); |
2890 | jermar | 329 | return NULL; |
330 | } |
||
2951 | jermar | 331 | node = fat_node_get_core(idx); |
332 | futex_up(&idx->lock); |
||
2822 | jermar | 333 | block_put(b); |
3516 | jermar | 334 | block_put(bb); |
2822 | jermar | 335 | return node; |
336 | } |
||
2793 | jermar | 337 | } |
2822 | jermar | 338 | block_put(b); |
2639 | jermar | 339 | } |
3516 | jermar | 340 | block_put(bb); |
341 | |||
2953 | jermar | 342 | futex_up(&parentp->idx->lock); |
2793 | jermar | 343 | return NULL; |
2638 | jermar | 344 | } |
345 | |||
2831 | jermar | 346 | static fs_index_t fat_index_get(void *node) |
347 | { |
||
348 | fat_node_t *fnodep = (fat_node_t *)node; |
||
349 | if (!fnodep) |
||
350 | return 0; |
||
2864 | jermar | 351 | return fnodep->idx->index; |
2831 | jermar | 352 | } |
353 | |||
354 | static size_t fat_size_get(void *node) |
||
355 | { |
||
356 | return ((fat_node_t *)node)->size; |
||
357 | } |
||
358 | |||
359 | static unsigned fat_lnkcnt_get(void *node) |
||
360 | { |
||
361 | return ((fat_node_t *)node)->lnkcnt; |
||
362 | } |
||
363 | |||
2845 | jermar | 364 | static bool fat_has_children(void *node) |
365 | { |
||
366 | fat_node_t *nodep = (fat_node_t *)node; |
||
367 | unsigned bps; |
||
368 | unsigned dps; |
||
369 | unsigned blocks; |
||
3516 | jermar | 370 | block_t *bb, *b; |
2845 | jermar | 371 | unsigned i, j; |
372 | |||
373 | if (nodep->type != FAT_DIRECTORY) |
||
374 | return false; |
||
375 | |||
2951 | jermar | 376 | futex_down(&nodep->idx->lock); |
3516 | jermar | 377 | bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE); |
378 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
2845 | jermar | 379 | dps = bps / sizeof(fat_dentry_t); |
380 | |||
381 | blocks = nodep->size / bps + (nodep->size % bps != 0); |
||
382 | |||
383 | for (i = 0; i < blocks; i++) { |
||
384 | unsigned dentries; |
||
385 | fat_dentry_t *d; |
||
386 | |||
3516 | jermar | 387 | b = fat_block_get(bb->data, nodep, i); |
2845 | jermar | 388 | dentries = (i == blocks - 1) ? |
389 | nodep->size % sizeof(fat_dentry_t) : |
||
390 | dps; |
||
391 | for (j = 0; j < dentries; j++) { |
||
392 | d = ((fat_dentry_t *)b->data) + j; |
||
393 | switch (fat_classify_dentry(d)) { |
||
394 | case FAT_DENTRY_SKIP: |
||
395 | continue; |
||
396 | case FAT_DENTRY_LAST: |
||
397 | block_put(b); |
||
3516 | jermar | 398 | block_put(bb); |
2951 | jermar | 399 | futex_up(&nodep->idx->lock); |
2845 | jermar | 400 | return false; |
401 | default: |
||
402 | case FAT_DENTRY_VALID: |
||
403 | block_put(b); |
||
3516 | jermar | 404 | block_put(bb); |
2951 | jermar | 405 | futex_up(&nodep->idx->lock); |
2845 | jermar | 406 | return true; |
407 | } |
||
408 | block_put(b); |
||
3516 | jermar | 409 | block_put(bb); |
2951 | jermar | 410 | futex_up(&nodep->idx->lock); |
2845 | jermar | 411 | return true; |
412 | } |
||
413 | block_put(b); |
||
414 | } |
||
3516 | jermar | 415 | block_put(bb); |
2845 | jermar | 416 | |
2951 | jermar | 417 | futex_up(&nodep->idx->lock); |
2845 | jermar | 418 | return false; |
419 | } |
||
420 | |||
2844 | jermar | 421 | static void *fat_root_get(dev_handle_t dev_handle) |
422 | { |
||
3119 | jermar | 423 | return fat_node_get(dev_handle, 0); |
2844 | jermar | 424 | } |
425 | |||
426 | static char fat_plb_get_char(unsigned pos) |
||
427 | { |
||
428 | return fat_reg.plb_ro[pos % PLB_SIZE]; |
||
429 | } |
||
430 | |||
2831 | jermar | 431 | static bool fat_is_directory(void *node) |
432 | { |
||
433 | return ((fat_node_t *)node)->type == FAT_DIRECTORY; |
||
434 | } |
||
435 | |||
436 | static bool fat_is_file(void *node) |
||
437 | { |
||
438 | return ((fat_node_t *)node)->type == FAT_FILE; |
||
439 | } |
||
440 | |||
2793 | jermar | 441 | /** libfs operations */ |
442 | libfs_ops_t fat_libfs_ops = { |
||
443 | .match = fat_match, |
||
444 | .node_get = fat_node_get, |
||
2852 | jermar | 445 | .node_put = fat_node_put, |
2857 | jermar | 446 | .create = fat_create, |
447 | .destroy = fat_destroy, |
||
448 | .link = fat_link, |
||
449 | .unlink = fat_unlink, |
||
2831 | jermar | 450 | .index_get = fat_index_get, |
451 | .size_get = fat_size_get, |
||
452 | .lnkcnt_get = fat_lnkcnt_get, |
||
2845 | jermar | 453 | .has_children = fat_has_children, |
2844 | jermar | 454 | .root_get = fat_root_get, |
455 | .plb_get_char = fat_plb_get_char, |
||
2831 | jermar | 456 | .is_directory = fat_is_directory, |
457 | .is_file = fat_is_file |
||
2793 | jermar | 458 | }; |
459 | |||
3110 | jermar | 460 | void fat_mounted(ipc_callid_t rid, ipc_call_t *request) |
461 | { |
||
462 | dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
||
3119 | jermar | 463 | block_t *bb; |
3257 | jermar | 464 | uint16_t bps; |
3119 | jermar | 465 | uint16_t rde; |
3110 | jermar | 466 | int rc; |
467 | |||
3257 | jermar | 468 | /* |
469 | * For now, we don't bother to remember dev_handle, dev_phone or |
||
470 | * dev_buffer in some data structure. We use global variables because we |
||
471 | * know there will be at most one mount on this file system. |
||
472 | * Of course, this is a huge TODO item. |
||
473 | */ |
||
474 | dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ | PROTO_WRITE, |
||
475 | MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); |
||
476 | |||
477 | if (!dev_buffer) { |
||
478 | ipc_answer_0(rid, ENOMEM); |
||
479 | return; |
||
480 | } |
||
481 | |||
482 | dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP, |
||
483 | DEVMAP_CONNECT_TO_DEVICE, dev_handle); |
||
484 | |||
485 | if (dev_phone < 0) { |
||
486 | munmap(dev_buffer, BS_SIZE); |
||
487 | ipc_answer_0(rid, dev_phone); |
||
488 | return; |
||
489 | } |
||
490 | |||
491 | rc = ipc_share_out_start(dev_phone, dev_buffer, |
||
492 | AS_AREA_READ | AS_AREA_WRITE); |
||
493 | if (rc != EOK) { |
||
494 | munmap(dev_buffer, BS_SIZE); |
||
495 | ipc_answer_0(rid, rc); |
||
496 | return; |
||
497 | } |
||
498 | |||
3119 | jermar | 499 | /* Read the number of root directory entries. */ |
3253 | jermar | 500 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
3257 | jermar | 501 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
3119 | jermar | 502 | rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max); |
503 | block_put(bb); |
||
504 | |||
3257 | jermar | 505 | if (bps != BS_SIZE) { |
506 | munmap(dev_buffer, BS_SIZE); |
||
507 | ipc_answer_0(rid, ENOTSUP); |
||
508 | return; |
||
509 | } |
||
510 | |||
3110 | jermar | 511 | rc = fat_idx_init_by_dev_handle(dev_handle); |
512 | if (rc != EOK) { |
||
3257 | jermar | 513 | munmap(dev_buffer, BS_SIZE); |
3110 | jermar | 514 | ipc_answer_0(rid, rc); |
515 | return; |
||
516 | } |
||
517 | |||
3119 | jermar | 518 | /* Initialize the root node. */ |
519 | fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t)); |
||
520 | if (!rootp) { |
||
3257 | jermar | 521 | munmap(dev_buffer, BS_SIZE); |
3119 | jermar | 522 | fat_idx_fini_by_dev_handle(dev_handle); |
523 | ipc_answer_0(rid, ENOMEM); |
||
524 | return; |
||
525 | } |
||
526 | fat_node_initialize(rootp); |
||
527 | |||
528 | fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0); |
||
529 | if (!ridxp) { |
||
3257 | jermar | 530 | munmap(dev_buffer, BS_SIZE); |
3119 | jermar | 531 | free(rootp); |
532 | fat_idx_fini_by_dev_handle(dev_handle); |
||
533 | ipc_answer_0(rid, ENOMEM); |
||
534 | return; |
||
535 | } |
||
536 | assert(ridxp->index == 0); |
||
537 | /* ridxp->lock held */ |
||
538 | |||
539 | rootp->type = FAT_DIRECTORY; |
||
540 | rootp->firstc = FAT_CLST_ROOT; |
||
541 | rootp->refcnt = 1; |
||
3352 | jermar | 542 | rootp->lnkcnt = 0; /* FS root is not linked */ |
3119 | jermar | 543 | rootp->size = rde * sizeof(fat_dentry_t); |
544 | rootp->idx = ridxp; |
||
545 | ridxp->nodep = rootp; |
||
546 | |||
547 | futex_up(&ridxp->lock); |
||
548 | |||
3352 | jermar | 549 | ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt); |
3110 | jermar | 550 | } |
551 | |||
552 | void fat_mount(ipc_callid_t rid, ipc_call_t *request) |
||
553 | { |
||
554 | ipc_answer_0(rid, ENOTSUP); |
||
555 | } |
||
556 | |||
2627 | jermar | 557 | void fat_lookup(ipc_callid_t rid, ipc_call_t *request) |
558 | { |
||
2793 | jermar | 559 | libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request); |
2627 | jermar | 560 | } |
561 | |||
3307 | jermar | 562 | void fat_read(ipc_callid_t rid, ipc_call_t *request) |
563 | { |
||
564 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
||
565 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
566 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
567 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
3516 | jermar | 568 | uint16_t bps; |
3308 | jermar | 569 | size_t bytes; |
3516 | jermar | 570 | block_t *bb, *b; |
3308 | jermar | 571 | |
3307 | jermar | 572 | if (!nodep) { |
573 | ipc_answer_0(rid, ENOENT); |
||
574 | return; |
||
575 | } |
||
576 | |||
577 | ipc_callid_t callid; |
||
578 | size_t len; |
||
3314 | jermar | 579 | if (!ipc_data_read_receive(&callid, &len)) { |
3307 | jermar | 580 | fat_node_put(nodep); |
581 | ipc_answer_0(callid, EINVAL); |
||
582 | ipc_answer_0(rid, EINVAL); |
||
583 | return; |
||
584 | } |
||
585 | |||
3516 | jermar | 586 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
587 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
588 | |||
3307 | jermar | 589 | if (nodep->type == FAT_FILE) { |
3335 | jermar | 590 | /* |
591 | * Our strategy for regular file reads is to read one block at |
||
592 | * most and make use of the possibility to return less data than |
||
593 | * requested. This keeps the code very simple. |
||
594 | */ |
||
3308 | jermar | 595 | bytes = min(len, bps - pos % bps); |
3516 | jermar | 596 | b = fat_block_get(bb->data, nodep, pos / bps); |
3308 | jermar | 597 | (void) ipc_data_read_finalize(callid, b->data + pos % bps, |
598 | bytes); |
||
599 | block_put(b); |
||
3307 | jermar | 600 | } else { |
3335 | jermar | 601 | unsigned bnum; |
602 | off_t spos = pos; |
||
603 | char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1]; |
||
604 | fat_dentry_t *d; |
||
605 | |||
3307 | jermar | 606 | assert(nodep->type == FAT_DIRECTORY); |
3335 | jermar | 607 | assert(nodep->size % bps == 0); |
608 | assert(bps % sizeof(fat_dentry_t) == 0); |
||
609 | |||
610 | /* |
||
611 | * Our strategy for readdir() is to use the position pointer as |
||
612 | * an index into the array of all dentries. On entry, it points |
||
613 | * to the first unread dentry. If we skip any dentries, we bump |
||
614 | * the position pointer accordingly. |
||
615 | */ |
||
616 | bnum = (pos * sizeof(fat_dentry_t)) / bps; |
||
617 | while (bnum < nodep->size / bps) { |
||
618 | off_t o; |
||
619 | |||
3516 | jermar | 620 | b = fat_block_get(bb->data, nodep, bnum); |
3335 | jermar | 621 | for (o = pos % (bps / sizeof(fat_dentry_t)); |
622 | o < bps / sizeof(fat_dentry_t); |
||
623 | o++, pos++) { |
||
624 | d = ((fat_dentry_t *)b->data) + o; |
||
625 | switch (fat_classify_dentry(d)) { |
||
626 | case FAT_DENTRY_SKIP: |
||
627 | continue; |
||
628 | case FAT_DENTRY_LAST: |
||
629 | block_put(b); |
||
630 | goto miss; |
||
631 | default: |
||
632 | case FAT_DENTRY_VALID: |
||
633 | dentry_name_canonify(d, name); |
||
634 | block_put(b); |
||
635 | goto hit; |
||
636 | } |
||
637 | } |
||
638 | block_put(b); |
||
639 | bnum++; |
||
640 | } |
||
641 | miss: |
||
3307 | jermar | 642 | fat_node_put(nodep); |
3516 | jermar | 643 | block_put(bb); |
3335 | jermar | 644 | ipc_answer_0(callid, ENOENT); |
645 | ipc_answer_1(rid, ENOENT, 0); |
||
3307 | jermar | 646 | return; |
3335 | jermar | 647 | hit: |
648 | (void) ipc_data_read_finalize(callid, name, strlen(name) + 1); |
||
649 | bytes = (pos - spos) + 1; |
||
3307 | jermar | 650 | } |
651 | |||
652 | fat_node_put(nodep); |
||
3516 | jermar | 653 | block_put(bb); |
3308 | jermar | 654 | ipc_answer_1(rid, EOK, (ipcarg_t)bytes); |
3307 | jermar | 655 | } |
656 | |||
3497 | jermar | 657 | void fat_write(ipc_callid_t rid, ipc_call_t *request) |
658 | { |
||
3499 | jermar | 659 | dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
660 | fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
||
661 | off_t pos = (off_t)IPC_GET_ARG3(*request); |
||
662 | fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
||
663 | size_t bytes; |
||
664 | block_t *b, *bb; |
||
665 | uint16_t bps; |
||
666 | unsigned spc; |
||
3501 | jermar | 667 | off_t boundary; |
3499 | jermar | 668 | |
669 | if (!nodep) { |
||
670 | ipc_answer_0(rid, ENOENT); |
||
671 | return; |
||
672 | } |
||
673 | |||
674 | /* XXX remove me when you are ready */ |
||
675 | { |
||
676 | ipc_answer_0(rid, ENOTSUP); |
||
677 | fat_node_put(nodep); |
||
678 | return; |
||
679 | } |
||
680 | |||
681 | ipc_callid_t callid; |
||
682 | size_t len; |
||
683 | if (!ipc_data_write_receive(&callid, &len)) { |
||
684 | fat_node_put(nodep); |
||
685 | ipc_answer_0(callid, EINVAL); |
||
686 | ipc_answer_0(rid, EINVAL); |
||
687 | return; |
||
688 | } |
||
689 | |||
690 | /* |
||
691 | * In all scenarios, we will attempt to write out only one block worth |
||
692 | * of data at maximum. There might be some more efficient approaches, |
||
693 | * but this one greatly simplifies fat_write(). Note that we can afford |
||
694 | * to do this because the client must be ready to handle the return |
||
695 | * value signalizing a smaller number of bytes written. |
||
696 | */ |
||
697 | bytes = min(len, bps - pos % bps); |
||
698 | |||
699 | bb = block_get(dev_handle, BS_BLOCK, BS_SIZE); |
||
700 | bps = uint16_t_le2host(FAT_BS(bb)->bps); |
||
701 | spc = FAT_BS(bb)->spc; |
||
702 | |||
3501 | jermar | 703 | boundary = ROUND_UP(nodep->size, bps * spc); |
704 | if (pos < boundary) { |
||
3499 | jermar | 705 | /* |
706 | * This is the easier case - we are either overwriting already |
||
707 | * existing contents or writing behind the EOF, but still within |
||
708 | * the limits of the last cluster. The node size may grow to the |
||
709 | * next block size boundary. |
||
710 | */ |
||
3516 | jermar | 711 | fat_fill_gap(bb->data, nodep, FAT_CLST_RES0, pos); |
712 | b = fat_block_get(bb->data, nodep, pos / bps); |
||
3499 | jermar | 713 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
714 | bytes); |
||
715 | b->dirty = true; /* need to sync block */ |
||
3500 | jermar | 716 | block_put(b); |
3499 | jermar | 717 | if (pos + bytes > nodep->size) { |
718 | nodep->size = pos + bytes; |
||
719 | nodep->dirty = true; /* need to sync node */ |
||
720 | } |
||
721 | fat_node_put(nodep); |
||
3516 | jermar | 722 | block_put(bb); |
3499 | jermar | 723 | ipc_answer_1(rid, EOK, bytes); |
724 | return; |
||
725 | } else { |
||
726 | /* |
||
727 | * This is the more difficult case. We must allocate new |
||
728 | * clusters for the node and zero them out. |
||
729 | */ |
||
3500 | jermar | 730 | int status; |
3499 | jermar | 731 | unsigned nclsts; |
3500 | jermar | 732 | fat_cluster_t mcl, lcl; |
733 | |||
3501 | jermar | 734 | nclsts = (ROUND_UP(pos + bytes, bps * spc) - boundary) / |
3500 | jermar | 735 | bps * spc; |
736 | /* create an independent chain of nclsts clusters in all FATs */ |
||
3516 | jermar | 737 | status = fat_alloc_clusters(bb->data, dev_handle, nclsts, &mcl, |
738 | &lcl); |
||
3500 | jermar | 739 | if (status != EOK) { |
740 | /* could not allocate a chain of nclsts clusters */ |
||
741 | fat_node_put(nodep); |
||
3516 | jermar | 742 | block_put(bb); |
3500 | jermar | 743 | ipc_answer_0(callid, status); |
744 | ipc_answer_0(rid, status); |
||
745 | return; |
||
746 | } |
||
747 | /* zero fill any gaps */ |
||
3516 | jermar | 748 | fat_fill_gap(bb->data, nodep, mcl, pos); |
749 | b = _fat_block_get(bb->data, dev_handle, lcl, |
||
750 | (pos / bps) % spc); |
||
3500 | jermar | 751 | (void) ipc_data_write_finalize(callid, b->data + pos % bps, |
752 | bytes); |
||
3501 | jermar | 753 | b->dirty = true; /* need to sync block */ |
3500 | jermar | 754 | block_put(b); |
755 | /* |
||
756 | * Append the cluster chain starting in mcl to the end of the |
||
757 | * node's cluster chain. |
||
758 | */ |
||
3516 | jermar | 759 | fat_append_clusters(bb->data, nodep, mcl); |
3500 | jermar | 760 | nodep->size = pos + bytes; |
3501 | jermar | 761 | nodep->dirty = true; /* need to sync node */ |
3500 | jermar | 762 | fat_node_put(nodep); |
3516 | jermar | 763 | block_put(bb); |
3500 | jermar | 764 | ipc_answer_1(rid, EOK, bytes); |
765 | return; |
||
3499 | jermar | 766 | } |
3497 | jermar | 767 | } |
768 | |||
2627 | jermar | 769 | /** |
770 | * @} |
||
771 | */ |