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