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USB: serial: f81232: fix interrupt worker not stop
[linux/fpc-iii.git] / fs / cachefiles / interface.c
blob222bc5d8b62c7204029dcc9b5e271a7d6d2a2b55
1 /* FS-Cache interface to CacheFiles
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12 #include <linux/slab.h>
13 #include <linux/mount.h>
14 #include "internal.h"
15
16 struct cachefiles_lookup_data {
17 struct cachefiles_xattr *auxdata; /* auxiliary data */
18 char *key; /* key path */
19 };
20
21 static int cachefiles_attr_changed(struct fscache_object *_object);
22
23 /*
24 * allocate an object record for a cookie lookup and prepare the lookup data
25 */
26 static struct fscache_object *cachefiles_alloc_object(
27 struct fscache_cache *_cache,
28 struct fscache_cookie *cookie)
29 {
30 struct cachefiles_lookup_data *lookup_data;
31 struct cachefiles_object *object;
32 struct cachefiles_cache *cache;
33 struct cachefiles_xattr *auxdata;
34 unsigned keylen, auxlen;
35 void *buffer, *p;
36 char *key;
37
38 cache = container_of(_cache, struct cachefiles_cache, cache);
39
40 _enter("{%s},%p,", cache->cache.identifier, cookie);
41
42 lookup_data = kmalloc(sizeof(*lookup_data), cachefiles_gfp);
43 if (!lookup_data)
44 goto nomem_lookup_data;
45
46 /* create a new object record and a temporary leaf image */
47 object = kmem_cache_alloc(cachefiles_object_jar, cachefiles_gfp);
48 if (!object)
49 goto nomem_object;
50
51 ASSERTCMP(object->backer, ==, NULL);
52
53 BUG_ON(test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
54 atomic_set(&object->usage, 1);
55
56 fscache_object_init(&object->fscache, cookie, &cache->cache);
57
58 object->type = cookie->def->type;
59
60 /* get hold of the raw key
61 * - stick the length on the front and leave space on the back for the
62 * encoder
63 */
64 buffer = kmalloc((2 + 512) + 3, cachefiles_gfp);
65 if (!buffer)
66 goto nomem_buffer;
67
68 keylen = cookie->key_len;
69 if (keylen <= sizeof(cookie->inline_key))
70 p = cookie->inline_key;
71 else
72 p = cookie->key;
73 memcpy(buffer + 2, p, keylen);
74
75 *(uint16_t *)buffer = keylen;
76 ((char *)buffer)[keylen + 2] = 0;
77 ((char *)buffer)[keylen + 3] = 0;
78 ((char *)buffer)[keylen + 4] = 0;
79
80 /* turn the raw key into something that can work with as a filename */
81 key = cachefiles_cook_key(buffer, keylen + 2, object->type);
82 if (!key)
83 goto nomem_key;
84
85 /* get hold of the auxiliary data and prepend the object type */
86 auxdata = buffer;
87 auxlen = cookie->aux_len;
88 if (auxlen) {
89 if (auxlen <= sizeof(cookie->inline_aux))
90 p = cookie->inline_aux;
91 else
92 p = cookie->aux;
93 memcpy(auxdata->data, p, auxlen);
94 }
95
96 auxdata->len = auxlen + 1;
97 auxdata->type = cookie->type;
98
99 lookup_data->auxdata = auxdata;
100 lookup_data->key = key;
101 object->lookup_data = lookup_data;
102
103 _leave(" = %p [%p]", &object->fscache, lookup_data);
104 return &object->fscache;
105
106 nomem_key:
107 kfree(buffer);
108 nomem_buffer:
109 BUG_ON(test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
110 kmem_cache_free(cachefiles_object_jar, object);
111 fscache_object_destroyed(&cache->cache);
112 nomem_object:
113 kfree(lookup_data);
114 nomem_lookup_data:
115 _leave(" = -ENOMEM");
116 return ERR_PTR(-ENOMEM);
117 }
118
119 /*
120 * attempt to look up the nominated node in this cache
121 * - return -ETIMEDOUT to be scheduled again
122 */
123 static int cachefiles_lookup_object(struct fscache_object *_object)
124 {
125 struct cachefiles_lookup_data *lookup_data;
126 struct cachefiles_object *parent, *object;
127 struct cachefiles_cache *cache;
128 const struct cred *saved_cred;
129 int ret;
130
131 _enter("{OBJ%x}", _object->debug_id);
132
133 cache = container_of(_object->cache, struct cachefiles_cache, cache);
134 parent = container_of(_object->parent,
135 struct cachefiles_object, fscache);
136 object = container_of(_object, struct cachefiles_object, fscache);
137 lookup_data = object->lookup_data;
138
139 ASSERTCMP(lookup_data, !=, NULL);
140
141 /* look up the key, creating any missing bits */
142 cachefiles_begin_secure(cache, &saved_cred);
143 ret = cachefiles_walk_to_object(parent, object,
144 lookup_data->key,
145 lookup_data->auxdata);
146 cachefiles_end_secure(cache, saved_cred);
147
148 /* polish off by setting the attributes of non-index files */
149 if (ret == 0 &&
150 object->fscache.cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX)
151 cachefiles_attr_changed(&object->fscache);
152
153 if (ret < 0 && ret != -ETIMEDOUT) {
154 if (ret != -ENOBUFS)
155 pr_warn("Lookup failed error %d\n", ret);
156 fscache_object_lookup_error(&object->fscache);
157 }
158
159 _leave(" [%d]", ret);
160 return ret;
161 }
162
163 /*
164 * indication of lookup completion
165 */
166 static void cachefiles_lookup_complete(struct fscache_object *_object)
167 {
168 struct cachefiles_object *object;
169
170 object = container_of(_object, struct cachefiles_object, fscache);
171
172 _enter("{OBJ%x,%p}", object->fscache.debug_id, object->lookup_data);
173
174 if (object->lookup_data) {
175 kfree(object->lookup_data->key);
176 kfree(object->lookup_data->auxdata);
177 kfree(object->lookup_data);
178 object->lookup_data = NULL;
179 }
180 }
181
182 /*
183 * increment the usage count on an inode object (may fail if unmounting)
184 */
185 static
186 struct fscache_object *cachefiles_grab_object(struct fscache_object *_object,
187 enum fscache_obj_ref_trace why)
188 {
189 struct cachefiles_object *object =
190 container_of(_object, struct cachefiles_object, fscache);
191 int u;
192
193 _enter("{OBJ%x,%d}", _object->debug_id, atomic_read(&object->usage));
194
195 #ifdef CACHEFILES_DEBUG_SLAB
196 ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000);
197 #endif
198
199 u = atomic_inc_return(&object->usage);
200 trace_cachefiles_ref(object, _object->cookie,
201 (enum cachefiles_obj_ref_trace)why, u);
202 return &object->fscache;
203 }
204
205 /*
206 * update the auxiliary data for an object object on disk
207 */
208 static void cachefiles_update_object(struct fscache_object *_object)
209 {
210 struct cachefiles_object *object;
211 struct cachefiles_xattr *auxdata;
212 struct cachefiles_cache *cache;
213 struct fscache_cookie *cookie;
214 const struct cred *saved_cred;
215 const void *aux;
216 unsigned auxlen;
217
218 _enter("{OBJ%x}", _object->debug_id);
219
220 object = container_of(_object, struct cachefiles_object, fscache);
221 cache = container_of(object->fscache.cache, struct cachefiles_cache,
222 cache);
223
224 if (!fscache_use_cookie(_object)) {
225 _leave(" [relinq]");
226 return;
227 }
228
229 cookie = object->fscache.cookie;
230 auxlen = cookie->aux_len;
231
232 if (!auxlen) {
233 fscache_unuse_cookie(_object);
234 _leave(" [no aux]");
235 return;
236 }
237
238 auxdata = kmalloc(2 + auxlen + 3, cachefiles_gfp);
239 if (!auxdata) {
240 fscache_unuse_cookie(_object);
241 _leave(" [nomem]");
242 return;
243 }
244
245 aux = (auxlen <= sizeof(cookie->inline_aux)) ?
246 cookie->inline_aux : cookie->aux;
247
248 memcpy(auxdata->data, aux, auxlen);
249 fscache_unuse_cookie(_object);
250
251 auxdata->len = auxlen + 1;
252 auxdata->type = cookie->type;
253
254 cachefiles_begin_secure(cache, &saved_cred);
255 cachefiles_update_object_xattr(object, auxdata);
256 cachefiles_end_secure(cache, saved_cred);
257 kfree(auxdata);
258 _leave("");
259 }
260
261 /*
262 * discard the resources pinned by an object and effect retirement if
263 * requested
264 */
265 static void cachefiles_drop_object(struct fscache_object *_object)
266 {
267 struct cachefiles_object *object;
268 struct cachefiles_cache *cache;
269 const struct cred *saved_cred;
270 struct inode *inode;
271 blkcnt_t i_blocks = 0;
272
273 ASSERT(_object);
274
275 object = container_of(_object, struct cachefiles_object, fscache);
276
277 _enter("{OBJ%x,%d}",
278 object->fscache.debug_id, atomic_read(&object->usage));
279
280 cache = container_of(object->fscache.cache,
281 struct cachefiles_cache, cache);
282
283 #ifdef CACHEFILES_DEBUG_SLAB
284 ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000);
285 #endif
286
287 /* We need to tidy the object up if we did in fact manage to open it.
288 * It's possible for us to get here before the object is fully
289 * initialised if the parent goes away or the object gets retired
290 * before we set it up.
291 */
292 if (object->dentry) {
293 /* delete retired objects */
294 if (test_bit(FSCACHE_OBJECT_RETIRED, &object->fscache.flags) &&
295 _object != cache->cache.fsdef
296 ) {
297 _debug("- retire object OBJ%x", object->fscache.debug_id);
298 inode = d_backing_inode(object->dentry);
299 if (inode)
300 i_blocks = inode->i_blocks;
301
302 cachefiles_begin_secure(cache, &saved_cred);
303 cachefiles_delete_object(cache, object);
304 cachefiles_end_secure(cache, saved_cred);
305 }
306
307 /* close the filesystem stuff attached to the object */
308 if (object->backer != object->dentry)
309 dput(object->backer);
310 object->backer = NULL;
311 }
312
313 /* note that the object is now inactive */
314 if (test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags))
315 cachefiles_mark_object_inactive(cache, object, i_blocks);
316
317 dput(object->dentry);
318 object->dentry = NULL;
319
320 _leave("");
321 }
322
323 /*
324 * dispose of a reference to an object
325 */
326 static void cachefiles_put_object(struct fscache_object *_object,
327 enum fscache_obj_ref_trace why)
328 {
329 struct cachefiles_object *object;
330 struct fscache_cache *cache;
331 int u;
332
333 ASSERT(_object);
334
335 object = container_of(_object, struct cachefiles_object, fscache);
336
337 _enter("{OBJ%x,%d}",
338 object->fscache.debug_id, atomic_read(&object->usage));
339
340 #ifdef CACHEFILES_DEBUG_SLAB
341 ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000);
342 #endif
343
344 ASSERTIFCMP(object->fscache.parent,
345 object->fscache.parent->n_children, >, 0);
346
347 u = atomic_dec_return(&object->usage);
348 trace_cachefiles_ref(object, _object->cookie,
349 (enum cachefiles_obj_ref_trace)why, u);
350 ASSERTCMP(u, !=, -1);
351 if (u == 0) {
352 _debug("- kill object OBJ%x", object->fscache.debug_id);
353
354 ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
355 ASSERTCMP(object->fscache.parent, ==, NULL);
356 ASSERTCMP(object->backer, ==, NULL);
357 ASSERTCMP(object->dentry, ==, NULL);
358 ASSERTCMP(object->fscache.n_ops, ==, 0);
359 ASSERTCMP(object->fscache.n_children, ==, 0);
360
361 if (object->lookup_data) {
362 kfree(object->lookup_data->key);
363 kfree(object->lookup_data->auxdata);
364 kfree(object->lookup_data);
365 object->lookup_data = NULL;
366 }
367
368 cache = object->fscache.cache;
369 fscache_object_destroy(&object->fscache);
370 kmem_cache_free(cachefiles_object_jar, object);
371 fscache_object_destroyed(cache);
372 }
373
374 _leave("");
375 }
376
377 /*
378 * sync a cache
379 */
380 static void cachefiles_sync_cache(struct fscache_cache *_cache)
381 {
382 struct cachefiles_cache *cache;
383 const struct cred *saved_cred;
384 int ret;
385
386 _enter("%p", _cache);
387
388 cache = container_of(_cache, struct cachefiles_cache, cache);
389
390 /* make sure all pages pinned by operations on behalf of the netfs are
391 * written to disc */
392 cachefiles_begin_secure(cache, &saved_cred);
393 down_read(&cache->mnt->mnt_sb->s_umount);
394 ret = sync_filesystem(cache->mnt->mnt_sb);
395 up_read(&cache->mnt->mnt_sb->s_umount);
396 cachefiles_end_secure(cache, saved_cred);
397
398 if (ret == -EIO)
399 cachefiles_io_error(cache,
400 "Attempt to sync backing fs superblock"
401 " returned error %d",
402 ret);
403 }
404
405 /*
406 * check if the backing cache is updated to FS-Cache
407 * - called by FS-Cache when evaluates if need to invalidate the cache
408 */
409 static int cachefiles_check_consistency(struct fscache_operation *op)
410 {
411 struct cachefiles_object *object;
412 struct cachefiles_cache *cache;
413 const struct cred *saved_cred;
414 int ret;
415
416 _enter("{OBJ%x}", op->object->debug_id);
417
418 object = container_of(op->object, struct cachefiles_object, fscache);
419 cache = container_of(object->fscache.cache,
420 struct cachefiles_cache, cache);
421
422 cachefiles_begin_secure(cache, &saved_cred);
423 ret = cachefiles_check_auxdata(object);
424 cachefiles_end_secure(cache, saved_cred);
425
426 _leave(" = %d", ret);
427 return ret;
428 }
429
430 /*
431 * notification the attributes on an object have changed
432 * - called with reads/writes excluded by FS-Cache
433 */
434 static int cachefiles_attr_changed(struct fscache_object *_object)
435 {
436 struct cachefiles_object *object;
437 struct cachefiles_cache *cache;
438 const struct cred *saved_cred;
439 struct iattr newattrs;
440 uint64_t ni_size;
441 loff_t oi_size;
442 int ret;
443
444 ni_size = _object->store_limit_l;
445
446 _enter("{OBJ%x},[%llu]",
447 _object->debug_id, (unsigned long long) ni_size);
448
449 object = container_of(_object, struct cachefiles_object, fscache);
450 cache = container_of(object->fscache.cache,
451 struct cachefiles_cache, cache);
452
453 if (ni_size == object->i_size)
454 return 0;
455
456 if (!object->backer)
457 return -ENOBUFS;
458
459 ASSERT(d_is_reg(object->backer));
460
461 fscache_set_store_limit(&object->fscache, ni_size);
462
463 oi_size = i_size_read(d_backing_inode(object->backer));
464 if (oi_size == ni_size)
465 return 0;
466
467 cachefiles_begin_secure(cache, &saved_cred);
468 inode_lock(d_inode(object->backer));
469
470 /* if there's an extension to a partial page at the end of the backing
471 * file, we need to discard the partial page so that we pick up new
472 * data after it */
473 if (oi_size & ~PAGE_MASK && ni_size > oi_size) {
474 _debug("discard tail %llx", oi_size);
475 newattrs.ia_valid = ATTR_SIZE;
476 newattrs.ia_size = oi_size & PAGE_MASK;
477 ret = notify_change(object->backer, &newattrs, NULL);
478 if (ret < 0)
479 goto truncate_failed;
480 }
481
482 newattrs.ia_valid = ATTR_SIZE;
483 newattrs.ia_size = ni_size;
484 ret = notify_change(object->backer, &newattrs, NULL);
485
486 truncate_failed:
487 inode_unlock(d_inode(object->backer));
488 cachefiles_end_secure(cache, saved_cred);
489
490 if (ret == -EIO) {
491 fscache_set_store_limit(&object->fscache, 0);
492 cachefiles_io_error_obj(object, "Size set failed");
493 ret = -ENOBUFS;
494 }
495
496 _leave(" = %d", ret);
497 return ret;
498 }
499
500 /*
501 * Invalidate an object
502 */
503 static void cachefiles_invalidate_object(struct fscache_operation *op)
504 {
505 struct cachefiles_object *object;
506 struct cachefiles_cache *cache;
507 const struct cred *saved_cred;
508 struct path path;
509 uint64_t ni_size;
510 int ret;
511
512 object = container_of(op->object, struct cachefiles_object, fscache);
513 cache = container_of(object->fscache.cache,
514 struct cachefiles_cache, cache);
515
516 ni_size = op->object->store_limit_l;
517
518 _enter("{OBJ%x},[%llu]",
519 op->object->debug_id, (unsigned long long)ni_size);
520
521 if (object->backer) {
522 ASSERT(d_is_reg(object->backer));
523
524 fscache_set_store_limit(&object->fscache, ni_size);
525
526 path.dentry = object->backer;
527 path.mnt = cache->mnt;
528
529 cachefiles_begin_secure(cache, &saved_cred);
530 ret = vfs_truncate(&path, 0);
531 if (ret == 0)
532 ret = vfs_truncate(&path, ni_size);
533 cachefiles_end_secure(cache, saved_cred);
534
535 if (ret != 0) {
536 fscache_set_store_limit(&object->fscache, 0);
537 if (ret == -EIO)
538 cachefiles_io_error_obj(object,
539 "Invalidate failed");
540 }
541 }
542
543 fscache_op_complete(op, true);
544 _leave("");
545 }
546
547 /*
548 * dissociate a cache from all the pages it was backing
549 */
550 static void cachefiles_dissociate_pages(struct fscache_cache *cache)
551 {
552 _enter("");
553 }
554
555 const struct fscache_cache_ops cachefiles_cache_ops = {
556 .name = "cachefiles",
557 .alloc_object = cachefiles_alloc_object,
558 .lookup_object = cachefiles_lookup_object,
559 .lookup_complete = cachefiles_lookup_complete,
560 .grab_object = cachefiles_grab_object,
561 .update_object = cachefiles_update_object,
562 .invalidate_object = cachefiles_invalidate_object,
563 .drop_object = cachefiles_drop_object,
564 .put_object = cachefiles_put_object,
565 .sync_cache = cachefiles_sync_cache,
566 .attr_changed = cachefiles_attr_changed,
567 .read_or_alloc_page = cachefiles_read_or_alloc_page,
568 .read_or_alloc_pages = cachefiles_read_or_alloc_pages,
569 .allocate_page = cachefiles_allocate_page,
570 .allocate_pages = cachefiles_allocate_pages,
571 .write_page = cachefiles_write_page,
572 .uncache_page = cachefiles_uncache_page,
573 .dissociate_pages = cachefiles_dissociate_pages,
574 .check_consistency = cachefiles_check_consistency,
575 };
Linux with added FPC-III support