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9ae326a6 DH |
1 | /* CacheFiles path walking and related routines |
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/module.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/file.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/fsnotify.h> | |
17 | #include <linux/quotaops.h> | |
18 | #include <linux/xattr.h> | |
19 | #include <linux/mount.h> | |
20 | #include <linux/namei.h> | |
21 | #include <linux/security.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
5d6c3191 | 23 | #include <linux/xattr.h> |
9ae326a6 DH |
24 | #include "internal.h" |
25 | ||
d0e27b78 DH |
26 | #define CACHEFILES_KEYBUF_SIZE 512 |
27 | ||
28 | /* | |
29 | * dump debugging info about an object | |
30 | */ | |
31 | static noinline | |
32 | void __cachefiles_printk_object(struct cachefiles_object *object, | |
33 | const char *prefix, | |
34 | u8 *keybuf) | |
35 | { | |
36 | struct fscache_cookie *cookie; | |
37 | unsigned keylen, loop; | |
38 | ||
4e1eb883 FF |
39 | pr_err("%sobject: OBJ%x\n", prefix, object->fscache.debug_id); |
40 | pr_err("%sobjstate=%s fl=%lx wbusy=%x ev=%lx[%lx]\n", | |
caaef690 | 41 | prefix, object->fscache.state->name, |
8b8edefa | 42 | object->fscache.flags, work_busy(&object->fscache.work), |
c2d35bfe | 43 | object->fscache.events, object->fscache.event_mask); |
4e1eb883 | 44 | pr_err("%sops=%u inp=%u exc=%u\n", |
d0e27b78 DH |
45 | prefix, object->fscache.n_ops, object->fscache.n_in_progress, |
46 | object->fscache.n_exclusive); | |
4e1eb883 | 47 | pr_err("%sparent=%p\n", |
d0e27b78 DH |
48 | prefix, object->fscache.parent); |
49 | ||
50 | spin_lock(&object->fscache.lock); | |
51 | cookie = object->fscache.cookie; | |
52 | if (cookie) { | |
4e1eb883 | 53 | pr_err("%scookie=%p [pr=%p nd=%p fl=%lx]\n", |
d0e27b78 DH |
54 | prefix, |
55 | object->fscache.cookie, | |
56 | object->fscache.cookie->parent, | |
57 | object->fscache.cookie->netfs_data, | |
58 | object->fscache.cookie->flags); | |
509bf24d | 59 | if (keybuf && cookie->def) |
d0e27b78 DH |
60 | keylen = cookie->def->get_key(cookie->netfs_data, keybuf, |
61 | CACHEFILES_KEYBUF_SIZE); | |
62 | else | |
63 | keylen = 0; | |
64 | } else { | |
4e1eb883 | 65 | pr_err("%scookie=NULL\n", prefix); |
d0e27b78 DH |
66 | keylen = 0; |
67 | } | |
68 | spin_unlock(&object->fscache.lock); | |
69 | ||
70 | if (keylen) { | |
4e1eb883 | 71 | pr_err("%skey=[%u] '", prefix, keylen); |
d0e27b78 | 72 | for (loop = 0; loop < keylen; loop++) |
4e1eb883 FF |
73 | pr_cont("%02x", keybuf[loop]); |
74 | pr_cont("'\n"); | |
d0e27b78 DH |
75 | } |
76 | } | |
77 | ||
78 | /* | |
79 | * dump debugging info about a pair of objects | |
80 | */ | |
81 | static noinline void cachefiles_printk_object(struct cachefiles_object *object, | |
82 | struct cachefiles_object *xobject) | |
83 | { | |
84 | u8 *keybuf; | |
85 | ||
86 | keybuf = kmalloc(CACHEFILES_KEYBUF_SIZE, GFP_NOIO); | |
87 | if (object) | |
88 | __cachefiles_printk_object(object, "", keybuf); | |
89 | if (xobject) | |
90 | __cachefiles_printk_object(xobject, "x", keybuf); | |
91 | kfree(keybuf); | |
92 | } | |
93 | ||
c61ea31d DH |
94 | /* |
95 | * mark the owner of a dentry, if there is one, to indicate that that dentry | |
96 | * has been preemptively deleted | |
97 | * - the caller must hold the i_mutex on the dentry's parent as required to | |
98 | * call vfs_unlink(), vfs_rmdir() or vfs_rename() | |
99 | */ | |
100 | static void cachefiles_mark_object_buried(struct cachefiles_cache *cache, | |
182d919b DH |
101 | struct dentry *dentry, |
102 | enum fscache_why_object_killed why) | |
c61ea31d DH |
103 | { |
104 | struct cachefiles_object *object; | |
105 | struct rb_node *p; | |
106 | ||
a455589f | 107 | _enter(",'%pd'", dentry); |
c61ea31d DH |
108 | |
109 | write_lock(&cache->active_lock); | |
110 | ||
111 | p = cache->active_nodes.rb_node; | |
112 | while (p) { | |
113 | object = rb_entry(p, struct cachefiles_object, active_node); | |
114 | if (object->dentry > dentry) | |
115 | p = p->rb_left; | |
116 | else if (object->dentry < dentry) | |
117 | p = p->rb_right; | |
118 | else | |
119 | goto found_dentry; | |
120 | } | |
121 | ||
122 | write_unlock(&cache->active_lock); | |
123 | _leave(" [no owner]"); | |
124 | return; | |
125 | ||
126 | /* found the dentry for */ | |
127 | found_dentry: | |
128 | kdebug("preemptive burial: OBJ%x [%s] %p", | |
129 | object->fscache.debug_id, | |
caaef690 | 130 | object->fscache.state->name, |
c61ea31d DH |
131 | dentry); |
132 | ||
493f7bc1 | 133 | if (fscache_object_is_live(&object->fscache)) { |
4e1eb883 | 134 | pr_err("\n"); |
0227d6ab | 135 | pr_err("Error: Can't preemptively bury live object\n"); |
c61ea31d | 136 | cachefiles_printk_object(object, NULL); |
182d919b DH |
137 | } else { |
138 | if (why != FSCACHE_OBJECT_IS_STALE) | |
139 | fscache_object_mark_killed(&object->fscache, why); | |
c61ea31d DH |
140 | } |
141 | ||
142 | write_unlock(&cache->active_lock); | |
143 | _leave(" [owner marked]"); | |
144 | } | |
145 | ||
9ae326a6 DH |
146 | /* |
147 | * record the fact that an object is now active | |
148 | */ | |
fee096de DH |
149 | static int cachefiles_mark_object_active(struct cachefiles_cache *cache, |
150 | struct cachefiles_object *object) | |
9ae326a6 DH |
151 | { |
152 | struct cachefiles_object *xobject; | |
153 | struct rb_node **_p, *_parent = NULL; | |
154 | struct dentry *dentry; | |
155 | ||
156 | _enter(",%p", object); | |
157 | ||
158 | try_again: | |
159 | write_lock(&cache->active_lock); | |
160 | ||
d0e27b78 | 161 | if (test_and_set_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) { |
0227d6ab | 162 | pr_err("Error: Object already active\n"); |
d0e27b78 | 163 | cachefiles_printk_object(object, NULL); |
9ae326a6 | 164 | BUG(); |
d0e27b78 | 165 | } |
9ae326a6 DH |
166 | |
167 | dentry = object->dentry; | |
168 | _p = &cache->active_nodes.rb_node; | |
169 | while (*_p) { | |
170 | _parent = *_p; | |
171 | xobject = rb_entry(_parent, | |
172 | struct cachefiles_object, active_node); | |
173 | ||
174 | ASSERT(xobject != object); | |
175 | ||
176 | if (xobject->dentry > dentry) | |
177 | _p = &(*_p)->rb_left; | |
178 | else if (xobject->dentry < dentry) | |
179 | _p = &(*_p)->rb_right; | |
180 | else | |
181 | goto wait_for_old_object; | |
182 | } | |
183 | ||
184 | rb_link_node(&object->active_node, _parent, _p); | |
185 | rb_insert_color(&object->active_node, &cache->active_nodes); | |
186 | ||
187 | write_unlock(&cache->active_lock); | |
fee096de DH |
188 | _leave(" = 0"); |
189 | return 0; | |
9ae326a6 DH |
190 | |
191 | /* an old object from a previous incarnation is hogging the slot - we | |
192 | * need to wait for it to be destroyed */ | |
193 | wait_for_old_object: | |
a30efe26 | 194 | if (fscache_object_is_live(&xobject->fscache)) { |
4e1eb883 | 195 | pr_err("\n"); |
0227d6ab | 196 | pr_err("Error: Unexpected object collision\n"); |
d0e27b78 | 197 | cachefiles_printk_object(object, xobject); |
9ae326a6 DH |
198 | BUG(); |
199 | } | |
200 | atomic_inc(&xobject->usage); | |
201 | write_unlock(&cache->active_lock); | |
202 | ||
fee096de DH |
203 | if (test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { |
204 | wait_queue_head_t *wq; | |
205 | ||
206 | signed long timeout = 60 * HZ; | |
207 | wait_queue_t wait; | |
208 | bool requeue; | |
209 | ||
210 | /* if the object we're waiting for is queued for processing, | |
211 | * then just put ourselves on the queue behind it */ | |
8b8edefa | 212 | if (work_pending(&xobject->fscache.work)) { |
fee096de DH |
213 | _debug("queue OBJ%x behind OBJ%x immediately", |
214 | object->fscache.debug_id, | |
215 | xobject->fscache.debug_id); | |
216 | goto requeue; | |
217 | } | |
218 | ||
219 | /* otherwise we sleep until either the object we're waiting for | |
8b8edefa | 220 | * is done, or the fscache_object is congested */ |
fee096de DH |
221 | wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE); |
222 | init_wait(&wait); | |
223 | requeue = false; | |
224 | do { | |
225 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
226 | if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) | |
227 | break; | |
8b8edefa TH |
228 | |
229 | requeue = fscache_object_sleep_till_congested(&timeout); | |
fee096de DH |
230 | } while (timeout > 0 && !requeue); |
231 | finish_wait(wq, &wait); | |
232 | ||
233 | if (requeue && | |
234 | test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { | |
235 | _debug("queue OBJ%x behind OBJ%x after wait", | |
236 | object->fscache.debug_id, | |
237 | xobject->fscache.debug_id); | |
238 | goto requeue; | |
239 | } | |
240 | ||
241 | if (timeout <= 0) { | |
4e1eb883 | 242 | pr_err("\n"); |
0227d6ab | 243 | pr_err("Error: Overlong wait for old active object to go away\n"); |
fee096de DH |
244 | cachefiles_printk_object(object, xobject); |
245 | goto requeue; | |
246 | } | |
247 | } | |
248 | ||
249 | ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)); | |
9ae326a6 DH |
250 | |
251 | cache->cache.ops->put_object(&xobject->fscache); | |
252 | goto try_again; | |
fee096de DH |
253 | |
254 | requeue: | |
255 | clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); | |
256 | cache->cache.ops->put_object(&xobject->fscache); | |
257 | _leave(" = -ETIMEDOUT"); | |
258 | return -ETIMEDOUT; | |
9ae326a6 DH |
259 | } |
260 | ||
a5b3a80b DH |
261 | /* |
262 | * Mark an object as being inactive. | |
263 | */ | |
264 | void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, | |
265 | struct cachefiles_object *object) | |
266 | { | |
db20a892 DH |
267 | blkcnt_t i_blocks = d_backing_inode(object->dentry)->i_blocks; |
268 | ||
a5b3a80b DH |
269 | write_lock(&cache->active_lock); |
270 | rb_erase(&object->active_node, &cache->active_nodes); | |
271 | clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); | |
272 | write_unlock(&cache->active_lock); | |
273 | ||
274 | wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE); | |
275 | ||
276 | /* This object can now be culled, so we need to let the daemon know | |
277 | * that there is something it can remove if it needs to. | |
278 | */ | |
db20a892 | 279 | atomic_long_add(i_blocks, &cache->b_released); |
a5b3a80b DH |
280 | if (atomic_inc_return(&cache->f_released)) |
281 | cachefiles_state_changed(cache); | |
282 | } | |
283 | ||
9ae326a6 DH |
284 | /* |
285 | * delete an object representation from the cache | |
286 | * - file backed objects are unlinked | |
287 | * - directory backed objects are stuffed into the graveyard for userspace to | |
288 | * delete | |
289 | * - unlocks the directory mutex | |
290 | */ | |
291 | static int cachefiles_bury_object(struct cachefiles_cache *cache, | |
292 | struct dentry *dir, | |
c61ea31d | 293 | struct dentry *rep, |
182d919b DH |
294 | bool preemptive, |
295 | enum fscache_why_object_killed why) | |
9ae326a6 DH |
296 | { |
297 | struct dentry *grave, *trap; | |
82140443 | 298 | struct path path, path_to_graveyard; |
9ae326a6 DH |
299 | char nbuffer[8 + 8 + 1]; |
300 | int ret; | |
301 | ||
a455589f | 302 | _enter(",'%pd','%pd'", dir, rep); |
9ae326a6 | 303 | |
c61ea31d DH |
304 | _debug("remove %p from %p", rep, dir); |
305 | ||
9ae326a6 | 306 | /* non-directories can just be unlinked */ |
e36cb0b8 | 307 | if (!d_is_dir(rep)) { |
9ae326a6 | 308 | _debug("unlink stale object"); |
9ae326a6 | 309 | |
82140443 DH |
310 | path.mnt = cache->mnt; |
311 | path.dentry = dir; | |
312 | ret = security_path_unlink(&path, rep); | |
313 | if (ret < 0) { | |
314 | cachefiles_io_error(cache, "Unlink security error"); | |
315 | } else { | |
5153bc81 | 316 | ret = vfs_unlink(d_inode(dir), rep, NULL); |
82140443 DH |
317 | |
318 | if (preemptive) | |
182d919b | 319 | cachefiles_mark_object_buried(cache, rep, why); |
82140443 | 320 | } |
c61ea31d | 321 | |
5955102c | 322 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
323 | |
324 | if (ret == -EIO) | |
325 | cachefiles_io_error(cache, "Unlink failed"); | |
326 | ||
327 | _leave(" = %d", ret); | |
328 | return ret; | |
329 | } | |
330 | ||
331 | /* directories have to be moved to the graveyard */ | |
332 | _debug("move stale object to graveyard"); | |
5955102c | 333 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
334 | |
335 | try_again: | |
336 | /* first step is to make up a grave dentry in the graveyard */ | |
337 | sprintf(nbuffer, "%08x%08x", | |
338 | (uint32_t) get_seconds(), | |
339 | (uint32_t) atomic_inc_return(&cache->gravecounter)); | |
340 | ||
341 | /* do the multiway lock magic */ | |
342 | trap = lock_rename(cache->graveyard, dir); | |
343 | ||
344 | /* do some checks before getting the grave dentry */ | |
345 | if (rep->d_parent != dir) { | |
346 | /* the entry was probably culled when we dropped the parent dir | |
347 | * lock */ | |
348 | unlock_rename(cache->graveyard, dir); | |
349 | _leave(" = 0 [culled?]"); | |
350 | return 0; | |
351 | } | |
352 | ||
ce40fa78 | 353 | if (!d_can_lookup(cache->graveyard)) { |
9ae326a6 DH |
354 | unlock_rename(cache->graveyard, dir); |
355 | cachefiles_io_error(cache, "Graveyard no longer a directory"); | |
356 | return -EIO; | |
357 | } | |
358 | ||
359 | if (trap == rep) { | |
360 | unlock_rename(cache->graveyard, dir); | |
361 | cachefiles_io_error(cache, "May not make directory loop"); | |
362 | return -EIO; | |
363 | } | |
364 | ||
365 | if (d_mountpoint(rep)) { | |
366 | unlock_rename(cache->graveyard, dir); | |
367 | cachefiles_io_error(cache, "Mountpoint in cache"); | |
368 | return -EIO; | |
369 | } | |
370 | ||
371 | grave = lookup_one_len(nbuffer, cache->graveyard, strlen(nbuffer)); | |
372 | if (IS_ERR(grave)) { | |
373 | unlock_rename(cache->graveyard, dir); | |
374 | ||
375 | if (PTR_ERR(grave) == -ENOMEM) { | |
376 | _leave(" = -ENOMEM"); | |
377 | return -ENOMEM; | |
378 | } | |
379 | ||
380 | cachefiles_io_error(cache, "Lookup error %ld", | |
381 | PTR_ERR(grave)); | |
382 | return -EIO; | |
383 | } | |
384 | ||
466b77bc | 385 | if (d_is_positive(grave)) { |
9ae326a6 DH |
386 | unlock_rename(cache->graveyard, dir); |
387 | dput(grave); | |
388 | grave = NULL; | |
389 | cond_resched(); | |
390 | goto try_again; | |
391 | } | |
392 | ||
393 | if (d_mountpoint(grave)) { | |
394 | unlock_rename(cache->graveyard, dir); | |
395 | dput(grave); | |
396 | cachefiles_io_error(cache, "Mountpoint in graveyard"); | |
397 | return -EIO; | |
398 | } | |
399 | ||
400 | /* target should not be an ancestor of source */ | |
401 | if (trap == grave) { | |
402 | unlock_rename(cache->graveyard, dir); | |
403 | dput(grave); | |
404 | cachefiles_io_error(cache, "May not make directory loop"); | |
405 | return -EIO; | |
406 | } | |
407 | ||
408 | /* attempt the rename */ | |
82140443 DH |
409 | path.mnt = cache->mnt; |
410 | path.dentry = dir; | |
411 | path_to_graveyard.mnt = cache->mnt; | |
412 | path_to_graveyard.dentry = cache->graveyard; | |
0b3974eb | 413 | ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0); |
82140443 DH |
414 | if (ret < 0) { |
415 | cachefiles_io_error(cache, "Rename security error %d", ret); | |
416 | } else { | |
5153bc81 DH |
417 | ret = vfs_rename(d_inode(dir), rep, |
418 | d_inode(cache->graveyard), grave, NULL, 0); | |
82140443 DH |
419 | if (ret != 0 && ret != -ENOMEM) |
420 | cachefiles_io_error(cache, | |
421 | "Rename failed with error %d", ret); | |
9ae326a6 | 422 | |
82140443 | 423 | if (preemptive) |
182d919b | 424 | cachefiles_mark_object_buried(cache, rep, why); |
82140443 | 425 | } |
c61ea31d | 426 | |
9ae326a6 DH |
427 | unlock_rename(cache->graveyard, dir); |
428 | dput(grave); | |
429 | _leave(" = 0"); | |
430 | return 0; | |
431 | } | |
432 | ||
433 | /* | |
434 | * delete an object representation from the cache | |
435 | */ | |
436 | int cachefiles_delete_object(struct cachefiles_cache *cache, | |
437 | struct cachefiles_object *object) | |
438 | { | |
439 | struct dentry *dir; | |
440 | int ret; | |
441 | ||
c61ea31d | 442 | _enter(",OBJ%x{%p}", object->fscache.debug_id, object->dentry); |
9ae326a6 DH |
443 | |
444 | ASSERT(object->dentry); | |
466b77bc | 445 | ASSERT(d_backing_inode(object->dentry)); |
9ae326a6 DH |
446 | ASSERT(object->dentry->d_parent); |
447 | ||
448 | dir = dget_parent(object->dentry); | |
449 | ||
5955102c | 450 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
8f9941ae | 451 | |
182d919b | 452 | if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) { |
c61ea31d DH |
453 | /* object allocation for the same key preemptively deleted this |
454 | * object's file so that it could create its own file */ | |
455 | _debug("object preemptively buried"); | |
5955102c | 456 | inode_unlock(d_inode(dir)); |
8f9941ae | 457 | ret = 0; |
c61ea31d DH |
458 | } else { |
459 | /* we need to check that our parent is _still_ our parent - it | |
460 | * may have been renamed */ | |
461 | if (dir == object->dentry->d_parent) { | |
462 | ret = cachefiles_bury_object(cache, dir, | |
182d919b DH |
463 | object->dentry, false, |
464 | FSCACHE_OBJECT_WAS_RETIRED); | |
c61ea31d DH |
465 | } else { |
466 | /* it got moved, presumably by cachefilesd culling it, | |
467 | * so it's no longer in the key path and we can ignore | |
468 | * it */ | |
5955102c | 469 | inode_unlock(d_inode(dir)); |
c61ea31d DH |
470 | ret = 0; |
471 | } | |
8f9941ae | 472 | } |
9ae326a6 DH |
473 | |
474 | dput(dir); | |
475 | _leave(" = %d", ret); | |
476 | return ret; | |
477 | } | |
478 | ||
479 | /* | |
480 | * walk from the parent object to the child object through the backing | |
481 | * filesystem, creating directories as we go | |
482 | */ | |
483 | int cachefiles_walk_to_object(struct cachefiles_object *parent, | |
484 | struct cachefiles_object *object, | |
485 | const char *key, | |
486 | struct cachefiles_xattr *auxdata) | |
487 | { | |
488 | struct cachefiles_cache *cache; | |
489 | struct dentry *dir, *next = NULL; | |
82140443 | 490 | struct path path; |
9ae326a6 DH |
491 | unsigned long start; |
492 | const char *name; | |
493 | int ret, nlen; | |
494 | ||
c61ea31d DH |
495 | _enter("OBJ%x{%p},OBJ%x,%s,", |
496 | parent->fscache.debug_id, parent->dentry, | |
497 | object->fscache.debug_id, key); | |
9ae326a6 DH |
498 | |
499 | cache = container_of(parent->fscache.cache, | |
500 | struct cachefiles_cache, cache); | |
82140443 | 501 | path.mnt = cache->mnt; |
9ae326a6 DH |
502 | |
503 | ASSERT(parent->dentry); | |
466b77bc | 504 | ASSERT(d_backing_inode(parent->dentry)); |
9ae326a6 | 505 | |
e36cb0b8 | 506 | if (!(d_is_dir(parent->dentry))) { |
9ae326a6 DH |
507 | // TODO: convert file to dir |
508 | _leave("looking up in none directory"); | |
509 | return -ENOBUFS; | |
510 | } | |
511 | ||
512 | dir = dget(parent->dentry); | |
513 | ||
514 | advance: | |
515 | /* attempt to transit the first directory component */ | |
516 | name = key; | |
517 | nlen = strlen(key); | |
518 | ||
519 | /* key ends in a double NUL */ | |
520 | key = key + nlen + 1; | |
521 | if (!*key) | |
522 | key = NULL; | |
523 | ||
524 | lookup_again: | |
525 | /* search the current directory for the element name */ | |
526 | _debug("lookup '%s'", name); | |
527 | ||
5955102c | 528 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
9ae326a6 DH |
529 | |
530 | start = jiffies; | |
531 | next = lookup_one_len(name, dir, nlen); | |
532 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
533 | if (IS_ERR(next)) | |
534 | goto lookup_error; | |
535 | ||
466b77bc | 536 | _debug("next -> %p %s", next, d_backing_inode(next) ? "positive" : "negative"); |
9ae326a6 DH |
537 | |
538 | if (!key) | |
466b77bc | 539 | object->new = !d_backing_inode(next); |
9ae326a6 DH |
540 | |
541 | /* if this element of the path doesn't exist, then the lookup phase | |
542 | * failed, and we can release any readers in the certain knowledge that | |
543 | * there's nothing for them to actually read */ | |
466b77bc | 544 | if (d_is_negative(next)) |
9ae326a6 DH |
545 | fscache_object_lookup_negative(&object->fscache); |
546 | ||
547 | /* we need to create the object if it's negative */ | |
548 | if (key || object->type == FSCACHE_COOKIE_TYPE_INDEX) { | |
549 | /* index objects and intervening tree levels must be subdirs */ | |
466b77bc | 550 | if (d_is_negative(next)) { |
9ae326a6 DH |
551 | ret = cachefiles_has_space(cache, 1, 0); |
552 | if (ret < 0) | |
182d919b | 553 | goto no_space_error; |
9ae326a6 | 554 | |
82140443 DH |
555 | path.dentry = dir; |
556 | ret = security_path_mkdir(&path, next, 0); | |
557 | if (ret < 0) | |
558 | goto create_error; | |
9ae326a6 | 559 | start = jiffies; |
5153bc81 | 560 | ret = vfs_mkdir(d_inode(dir), next, 0); |
9ae326a6 DH |
561 | cachefiles_hist(cachefiles_mkdir_histogram, start); |
562 | if (ret < 0) | |
563 | goto create_error; | |
564 | ||
466b77bc | 565 | ASSERT(d_backing_inode(next)); |
9ae326a6 DH |
566 | |
567 | _debug("mkdir -> %p{%p{ino=%lu}}", | |
466b77bc | 568 | next, d_backing_inode(next), d_backing_inode(next)->i_ino); |
9ae326a6 | 569 | |
ce40fa78 | 570 | } else if (!d_can_lookup(next)) { |
6ff66ac7 | 571 | pr_err("inode %lu is not a directory\n", |
466b77bc | 572 | d_backing_inode(next)->i_ino); |
9ae326a6 DH |
573 | ret = -ENOBUFS; |
574 | goto error; | |
575 | } | |
576 | ||
577 | } else { | |
578 | /* non-index objects start out life as files */ | |
466b77bc | 579 | if (d_is_negative(next)) { |
9ae326a6 DH |
580 | ret = cachefiles_has_space(cache, 1, 0); |
581 | if (ret < 0) | |
182d919b | 582 | goto no_space_error; |
9ae326a6 | 583 | |
82140443 DH |
584 | path.dentry = dir; |
585 | ret = security_path_mknod(&path, next, S_IFREG, 0); | |
586 | if (ret < 0) | |
587 | goto create_error; | |
9ae326a6 | 588 | start = jiffies; |
5153bc81 | 589 | ret = vfs_create(d_inode(dir), next, S_IFREG, true); |
9ae326a6 DH |
590 | cachefiles_hist(cachefiles_create_histogram, start); |
591 | if (ret < 0) | |
592 | goto create_error; | |
593 | ||
466b77bc | 594 | ASSERT(d_backing_inode(next)); |
9ae326a6 DH |
595 | |
596 | _debug("create -> %p{%p{ino=%lu}}", | |
466b77bc | 597 | next, d_backing_inode(next), d_backing_inode(next)->i_ino); |
9ae326a6 | 598 | |
ce40fa78 | 599 | } else if (!d_can_lookup(next) && |
e36cb0b8 | 600 | !d_is_reg(next) |
9ae326a6 | 601 | ) { |
6ff66ac7 | 602 | pr_err("inode %lu is not a file or directory\n", |
466b77bc | 603 | d_backing_inode(next)->i_ino); |
9ae326a6 DH |
604 | ret = -ENOBUFS; |
605 | goto error; | |
606 | } | |
607 | } | |
608 | ||
609 | /* process the next component */ | |
610 | if (key) { | |
611 | _debug("advance"); | |
5955102c | 612 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
613 | dput(dir); |
614 | dir = next; | |
615 | next = NULL; | |
616 | goto advance; | |
617 | } | |
618 | ||
619 | /* we've found the object we were looking for */ | |
620 | object->dentry = next; | |
621 | ||
622 | /* if we've found that the terminal object exists, then we need to | |
623 | * check its attributes and delete it if it's out of date */ | |
624 | if (!object->new) { | |
a455589f | 625 | _debug("validate '%pd'", next); |
9ae326a6 DH |
626 | |
627 | ret = cachefiles_check_object_xattr(object, auxdata); | |
628 | if (ret == -ESTALE) { | |
629 | /* delete the object (the deleter drops the directory | |
630 | * mutex) */ | |
631 | object->dentry = NULL; | |
632 | ||
182d919b DH |
633 | ret = cachefiles_bury_object(cache, dir, next, true, |
634 | FSCACHE_OBJECT_IS_STALE); | |
9ae326a6 DH |
635 | dput(next); |
636 | next = NULL; | |
637 | ||
638 | if (ret < 0) | |
639 | goto delete_error; | |
640 | ||
641 | _debug("redo lookup"); | |
182d919b | 642 | fscache_object_retrying_stale(&object->fscache); |
9ae326a6 DH |
643 | goto lookup_again; |
644 | } | |
645 | } | |
646 | ||
647 | /* note that we're now using this object */ | |
fee096de | 648 | ret = cachefiles_mark_object_active(cache, object); |
9ae326a6 | 649 | |
5955102c | 650 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
651 | dput(dir); |
652 | dir = NULL; | |
653 | ||
fee096de DH |
654 | if (ret == -ETIMEDOUT) |
655 | goto mark_active_timed_out; | |
656 | ||
9ae326a6 DH |
657 | _debug("=== OBTAINED_OBJECT ==="); |
658 | ||
659 | if (object->new) { | |
660 | /* attach data to a newly constructed terminal object */ | |
661 | ret = cachefiles_set_object_xattr(object, auxdata); | |
662 | if (ret < 0) | |
663 | goto check_error; | |
664 | } else { | |
665 | /* always update the atime on an object we've just looked up | |
666 | * (this is used to keep track of culling, and atimes are only | |
667 | * updated by read, write and readdir but not lookup or | |
668 | * open) */ | |
68ac1234 AV |
669 | path.dentry = next; |
670 | touch_atime(&path); | |
9ae326a6 DH |
671 | } |
672 | ||
673 | /* open a file interface onto a data file */ | |
674 | if (object->type != FSCACHE_COOKIE_TYPE_INDEX) { | |
e36cb0b8 | 675 | if (d_is_reg(object->dentry)) { |
9ae326a6 DH |
676 | const struct address_space_operations *aops; |
677 | ||
678 | ret = -EPERM; | |
466b77bc | 679 | aops = d_backing_inode(object->dentry)->i_mapping->a_ops; |
9ae326a6 DH |
680 | if (!aops->bmap) |
681 | goto check_error; | |
95201a40 N |
682 | if (object->dentry->d_sb->s_blocksize > PAGE_SIZE) |
683 | goto check_error; | |
9ae326a6 DH |
684 | |
685 | object->backer = object->dentry; | |
686 | } else { | |
687 | BUG(); // TODO: open file in data-class subdir | |
688 | } | |
689 | } | |
690 | ||
691 | object->new = 0; | |
692 | fscache_obtained_object(&object->fscache); | |
693 | ||
466b77bc | 694 | _leave(" = 0 [%lu]", d_backing_inode(object->dentry)->i_ino); |
9ae326a6 DH |
695 | return 0; |
696 | ||
182d919b DH |
697 | no_space_error: |
698 | fscache_object_mark_killed(&object->fscache, FSCACHE_OBJECT_NO_SPACE); | |
9ae326a6 DH |
699 | create_error: |
700 | _debug("create error %d", ret); | |
701 | if (ret == -EIO) | |
702 | cachefiles_io_error(cache, "Create/mkdir failed"); | |
703 | goto error; | |
704 | ||
fee096de DH |
705 | mark_active_timed_out: |
706 | _debug("mark active timed out"); | |
707 | goto release_dentry; | |
708 | ||
9ae326a6 DH |
709 | check_error: |
710 | _debug("check error %d", ret); | |
a5b3a80b | 711 | cachefiles_mark_object_inactive(cache, object); |
fee096de | 712 | release_dentry: |
9ae326a6 DH |
713 | dput(object->dentry); |
714 | object->dentry = NULL; | |
715 | goto error_out; | |
716 | ||
717 | delete_error: | |
718 | _debug("delete error %d", ret); | |
719 | goto error_out2; | |
720 | ||
721 | lookup_error: | |
722 | _debug("lookup error %ld", PTR_ERR(next)); | |
723 | ret = PTR_ERR(next); | |
724 | if (ret == -EIO) | |
725 | cachefiles_io_error(cache, "Lookup failed"); | |
726 | next = NULL; | |
727 | error: | |
5955102c | 728 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
729 | dput(next); |
730 | error_out2: | |
731 | dput(dir); | |
732 | error_out: | |
9ae326a6 DH |
733 | _leave(" = error %d", -ret); |
734 | return ret; | |
735 | } | |
736 | ||
737 | /* | |
738 | * get a subdirectory | |
739 | */ | |
740 | struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, | |
741 | struct dentry *dir, | |
742 | const char *dirname) | |
743 | { | |
744 | struct dentry *subdir; | |
745 | unsigned long start; | |
82140443 | 746 | struct path path; |
9ae326a6 DH |
747 | int ret; |
748 | ||
749 | _enter(",,%s", dirname); | |
750 | ||
751 | /* search the current directory for the element name */ | |
5955102c | 752 | inode_lock(d_inode(dir)); |
9ae326a6 DH |
753 | |
754 | start = jiffies; | |
755 | subdir = lookup_one_len(dirname, dir, strlen(dirname)); | |
756 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
757 | if (IS_ERR(subdir)) { | |
758 | if (PTR_ERR(subdir) == -ENOMEM) | |
759 | goto nomem_d_alloc; | |
760 | goto lookup_error; | |
761 | } | |
762 | ||
763 | _debug("subdir -> %p %s", | |
466b77bc | 764 | subdir, d_backing_inode(subdir) ? "positive" : "negative"); |
9ae326a6 DH |
765 | |
766 | /* we need to create the subdir if it doesn't exist yet */ | |
466b77bc | 767 | if (d_is_negative(subdir)) { |
9ae326a6 DH |
768 | ret = cachefiles_has_space(cache, 1, 0); |
769 | if (ret < 0) | |
770 | goto mkdir_error; | |
771 | ||
772 | _debug("attempt mkdir"); | |
773 | ||
82140443 DH |
774 | path.mnt = cache->mnt; |
775 | path.dentry = dir; | |
776 | ret = security_path_mkdir(&path, subdir, 0700); | |
777 | if (ret < 0) | |
778 | goto mkdir_error; | |
5153bc81 | 779 | ret = vfs_mkdir(d_inode(dir), subdir, 0700); |
9ae326a6 DH |
780 | if (ret < 0) |
781 | goto mkdir_error; | |
782 | ||
466b77bc | 783 | ASSERT(d_backing_inode(subdir)); |
9ae326a6 DH |
784 | |
785 | _debug("mkdir -> %p{%p{ino=%lu}}", | |
786 | subdir, | |
466b77bc DH |
787 | d_backing_inode(subdir), |
788 | d_backing_inode(subdir)->i_ino); | |
9ae326a6 DH |
789 | } |
790 | ||
5955102c | 791 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
792 | |
793 | /* we need to make sure the subdir is a directory */ | |
466b77bc | 794 | ASSERT(d_backing_inode(subdir)); |
9ae326a6 | 795 | |
ce40fa78 | 796 | if (!d_can_lookup(subdir)) { |
6ff66ac7 | 797 | pr_err("%s is not a directory\n", dirname); |
9ae326a6 DH |
798 | ret = -EIO; |
799 | goto check_error; | |
800 | } | |
801 | ||
802 | ret = -EPERM; | |
5d6c3191 | 803 | if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) || |
466b77bc DH |
804 | !d_backing_inode(subdir)->i_op->lookup || |
805 | !d_backing_inode(subdir)->i_op->mkdir || | |
806 | !d_backing_inode(subdir)->i_op->create || | |
807 | (!d_backing_inode(subdir)->i_op->rename && | |
808 | !d_backing_inode(subdir)->i_op->rename2) || | |
809 | !d_backing_inode(subdir)->i_op->rmdir || | |
810 | !d_backing_inode(subdir)->i_op->unlink) | |
9ae326a6 DH |
811 | goto check_error; |
812 | ||
466b77bc | 813 | _leave(" = [%lu]", d_backing_inode(subdir)->i_ino); |
9ae326a6 DH |
814 | return subdir; |
815 | ||
816 | check_error: | |
817 | dput(subdir); | |
818 | _leave(" = %d [check]", ret); | |
819 | return ERR_PTR(ret); | |
820 | ||
821 | mkdir_error: | |
5955102c | 822 | inode_unlock(d_inode(dir)); |
9ae326a6 | 823 | dput(subdir); |
6ff66ac7 | 824 | pr_err("mkdir %s failed with error %d\n", dirname, ret); |
9ae326a6 DH |
825 | return ERR_PTR(ret); |
826 | ||
827 | lookup_error: | |
5955102c | 828 | inode_unlock(d_inode(dir)); |
9ae326a6 | 829 | ret = PTR_ERR(subdir); |
6ff66ac7 | 830 | pr_err("Lookup %s failed with error %d\n", dirname, ret); |
9ae326a6 DH |
831 | return ERR_PTR(ret); |
832 | ||
833 | nomem_d_alloc: | |
5955102c | 834 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
835 | _leave(" = -ENOMEM"); |
836 | return ERR_PTR(-ENOMEM); | |
837 | } | |
838 | ||
839 | /* | |
840 | * find out if an object is in use or not | |
841 | * - if finds object and it's not in use: | |
842 | * - returns a pointer to the object and a reference on it | |
843 | * - returns with the directory locked | |
844 | */ | |
845 | static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache, | |
846 | struct dentry *dir, | |
847 | char *filename) | |
848 | { | |
849 | struct cachefiles_object *object; | |
850 | struct rb_node *_n; | |
851 | struct dentry *victim; | |
852 | unsigned long start; | |
853 | int ret; | |
854 | ||
a455589f AV |
855 | //_enter(",%pd/,%s", |
856 | // dir, filename); | |
9ae326a6 DH |
857 | |
858 | /* look up the victim */ | |
5955102c | 859 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
9ae326a6 DH |
860 | |
861 | start = jiffies; | |
862 | victim = lookup_one_len(filename, dir, strlen(filename)); | |
863 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
864 | if (IS_ERR(victim)) | |
865 | goto lookup_error; | |
866 | ||
867 | //_debug("victim -> %p %s", | |
466b77bc | 868 | // victim, d_backing_inode(victim) ? "positive" : "negative"); |
9ae326a6 DH |
869 | |
870 | /* if the object is no longer there then we probably retired the object | |
871 | * at the netfs's request whilst the cull was in progress | |
872 | */ | |
466b77bc | 873 | if (d_is_negative(victim)) { |
5955102c | 874 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
875 | dput(victim); |
876 | _leave(" = -ENOENT [absent]"); | |
877 | return ERR_PTR(-ENOENT); | |
878 | } | |
879 | ||
880 | /* check to see if we're using this object */ | |
881 | read_lock(&cache->active_lock); | |
882 | ||
883 | _n = cache->active_nodes.rb_node; | |
884 | ||
885 | while (_n) { | |
886 | object = rb_entry(_n, struct cachefiles_object, active_node); | |
887 | ||
888 | if (object->dentry > victim) | |
889 | _n = _n->rb_left; | |
890 | else if (object->dentry < victim) | |
891 | _n = _n->rb_right; | |
892 | else | |
893 | goto object_in_use; | |
894 | } | |
895 | ||
896 | read_unlock(&cache->active_lock); | |
897 | ||
898 | //_leave(" = %p", victim); | |
899 | return victim; | |
900 | ||
901 | object_in_use: | |
902 | read_unlock(&cache->active_lock); | |
5955102c | 903 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
904 | dput(victim); |
905 | //_leave(" = -EBUSY [in use]"); | |
906 | return ERR_PTR(-EBUSY); | |
907 | ||
908 | lookup_error: | |
5955102c | 909 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
910 | ret = PTR_ERR(victim); |
911 | if (ret == -ENOENT) { | |
912 | /* file or dir now absent - probably retired by netfs */ | |
913 | _leave(" = -ESTALE [absent]"); | |
914 | return ERR_PTR(-ESTALE); | |
915 | } | |
916 | ||
917 | if (ret == -EIO) { | |
918 | cachefiles_io_error(cache, "Lookup failed"); | |
919 | } else if (ret != -ENOMEM) { | |
6ff66ac7 | 920 | pr_err("Internal error: %d\n", ret); |
9ae326a6 DH |
921 | ret = -EIO; |
922 | } | |
923 | ||
924 | _leave(" = %d", ret); | |
925 | return ERR_PTR(ret); | |
926 | } | |
927 | ||
928 | /* | |
929 | * cull an object if it's not in use | |
930 | * - called only by cache manager daemon | |
931 | */ | |
932 | int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, | |
933 | char *filename) | |
934 | { | |
935 | struct dentry *victim; | |
936 | int ret; | |
937 | ||
a455589f | 938 | _enter(",%pd/,%s", dir, filename); |
9ae326a6 DH |
939 | |
940 | victim = cachefiles_check_active(cache, dir, filename); | |
941 | if (IS_ERR(victim)) | |
942 | return PTR_ERR(victim); | |
943 | ||
944 | _debug("victim -> %p %s", | |
466b77bc | 945 | victim, d_backing_inode(victim) ? "positive" : "negative"); |
9ae326a6 DH |
946 | |
947 | /* okay... the victim is not being used so we can cull it | |
948 | * - start by marking it as stale | |
949 | */ | |
950 | _debug("victim is cullable"); | |
951 | ||
952 | ret = cachefiles_remove_object_xattr(cache, victim); | |
953 | if (ret < 0) | |
954 | goto error_unlock; | |
955 | ||
956 | /* actually remove the victim (drops the dir mutex) */ | |
957 | _debug("bury"); | |
958 | ||
182d919b DH |
959 | ret = cachefiles_bury_object(cache, dir, victim, false, |
960 | FSCACHE_OBJECT_WAS_CULLED); | |
9ae326a6 DH |
961 | if (ret < 0) |
962 | goto error; | |
963 | ||
964 | dput(victim); | |
965 | _leave(" = 0"); | |
966 | return 0; | |
967 | ||
968 | error_unlock: | |
5955102c | 969 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
970 | error: |
971 | dput(victim); | |
972 | if (ret == -ENOENT) { | |
973 | /* file or dir now absent - probably retired by netfs */ | |
974 | _leave(" = -ESTALE [absent]"); | |
975 | return -ESTALE; | |
976 | } | |
977 | ||
978 | if (ret != -ENOMEM) { | |
6ff66ac7 | 979 | pr_err("Internal error: %d\n", ret); |
9ae326a6 DH |
980 | ret = -EIO; |
981 | } | |
982 | ||
983 | _leave(" = %d", ret); | |
984 | return ret; | |
985 | } | |
986 | ||
987 | /* | |
988 | * find out if an object is in use or not | |
989 | * - called only by cache manager daemon | |
990 | * - returns -EBUSY or 0 to indicate whether an object is in use or not | |
991 | */ | |
992 | int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir, | |
993 | char *filename) | |
994 | { | |
995 | struct dentry *victim; | |
996 | ||
a455589f AV |
997 | //_enter(",%pd/,%s", |
998 | // dir, filename); | |
9ae326a6 DH |
999 | |
1000 | victim = cachefiles_check_active(cache, dir, filename); | |
1001 | if (IS_ERR(victim)) | |
1002 | return PTR_ERR(victim); | |
1003 | ||
5955102c | 1004 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
1005 | dput(victim); |
1006 | //_leave(" = 0"); | |
1007 | return 0; | |
1008 | } |