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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, | |
402cb8dd | 33 | const char *prefix) |
d0e27b78 DH |
34 | { |
35 | struct fscache_cookie *cookie; | |
402cb8dd DH |
36 | const u8 *k; |
37 | unsigned loop; | |
d0e27b78 | 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); | |
402cb8dd DH |
59 | pr_err("%skey=[%u] '", prefix, cookie->key_len); |
60 | k = (cookie->key_len <= sizeof(cookie->inline_key)) ? | |
61 | cookie->inline_key : cookie->key; | |
62 | for (loop = 0; loop < cookie->key_len; loop++) | |
63 | pr_cont("%02x", k[loop]); | |
64 | pr_cont("'\n"); | |
d0e27b78 | 65 | } else { |
4e1eb883 | 66 | pr_err("%scookie=NULL\n", prefix); |
d0e27b78 DH |
67 | } |
68 | spin_unlock(&object->fscache.lock); | |
d0e27b78 DH |
69 | } |
70 | ||
71 | /* | |
72 | * dump debugging info about a pair of objects | |
73 | */ | |
74 | static noinline void cachefiles_printk_object(struct cachefiles_object *object, | |
75 | struct cachefiles_object *xobject) | |
76 | { | |
d0e27b78 | 77 | if (object) |
402cb8dd | 78 | __cachefiles_printk_object(object, ""); |
d0e27b78 | 79 | if (xobject) |
402cb8dd | 80 | __cachefiles_printk_object(xobject, "x"); |
d0e27b78 DH |
81 | } |
82 | ||
c61ea31d DH |
83 | /* |
84 | * mark the owner of a dentry, if there is one, to indicate that that dentry | |
85 | * has been preemptively deleted | |
86 | * - the caller must hold the i_mutex on the dentry's parent as required to | |
87 | * call vfs_unlink(), vfs_rmdir() or vfs_rename() | |
88 | */ | |
89 | static void cachefiles_mark_object_buried(struct cachefiles_cache *cache, | |
182d919b DH |
90 | struct dentry *dentry, |
91 | enum fscache_why_object_killed why) | |
c61ea31d DH |
92 | { |
93 | struct cachefiles_object *object; | |
94 | struct rb_node *p; | |
95 | ||
a455589f | 96 | _enter(",'%pd'", dentry); |
c61ea31d DH |
97 | |
98 | write_lock(&cache->active_lock); | |
99 | ||
100 | p = cache->active_nodes.rb_node; | |
101 | while (p) { | |
102 | object = rb_entry(p, struct cachefiles_object, active_node); | |
103 | if (object->dentry > dentry) | |
104 | p = p->rb_left; | |
105 | else if (object->dentry < dentry) | |
106 | p = p->rb_right; | |
107 | else | |
108 | goto found_dentry; | |
109 | } | |
110 | ||
111 | write_unlock(&cache->active_lock); | |
a18feb55 | 112 | trace_cachefiles_mark_buried(NULL, dentry, why); |
c61ea31d DH |
113 | _leave(" [no owner]"); |
114 | return; | |
115 | ||
116 | /* found the dentry for */ | |
117 | found_dentry: | |
118 | kdebug("preemptive burial: OBJ%x [%s] %p", | |
119 | object->fscache.debug_id, | |
caaef690 | 120 | object->fscache.state->name, |
c61ea31d DH |
121 | dentry); |
122 | ||
a18feb55 DH |
123 | trace_cachefiles_mark_buried(object, dentry, why); |
124 | ||
493f7bc1 | 125 | if (fscache_object_is_live(&object->fscache)) { |
4e1eb883 | 126 | pr_err("\n"); |
0227d6ab | 127 | pr_err("Error: Can't preemptively bury live object\n"); |
c61ea31d | 128 | cachefiles_printk_object(object, NULL); |
182d919b DH |
129 | } else { |
130 | if (why != FSCACHE_OBJECT_IS_STALE) | |
131 | fscache_object_mark_killed(&object->fscache, why); | |
c61ea31d DH |
132 | } |
133 | ||
134 | write_unlock(&cache->active_lock); | |
135 | _leave(" [owner marked]"); | |
136 | } | |
137 | ||
9ae326a6 DH |
138 | /* |
139 | * record the fact that an object is now active | |
140 | */ | |
fee096de DH |
141 | static int cachefiles_mark_object_active(struct cachefiles_cache *cache, |
142 | struct cachefiles_object *object) | |
9ae326a6 DH |
143 | { |
144 | struct cachefiles_object *xobject; | |
145 | struct rb_node **_p, *_parent = NULL; | |
146 | struct dentry *dentry; | |
147 | ||
148 | _enter(",%p", object); | |
149 | ||
150 | try_again: | |
151 | write_lock(&cache->active_lock); | |
152 | ||
a18feb55 DH |
153 | dentry = object->dentry; |
154 | trace_cachefiles_mark_active(object, dentry); | |
155 | ||
d0e27b78 | 156 | if (test_and_set_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) { |
0227d6ab | 157 | pr_err("Error: Object already active\n"); |
d0e27b78 | 158 | cachefiles_printk_object(object, NULL); |
9ae326a6 | 159 | BUG(); |
d0e27b78 | 160 | } |
9ae326a6 | 161 | |
9ae326a6 DH |
162 | _p = &cache->active_nodes.rb_node; |
163 | while (*_p) { | |
164 | _parent = *_p; | |
165 | xobject = rb_entry(_parent, | |
166 | struct cachefiles_object, active_node); | |
167 | ||
168 | ASSERT(xobject != object); | |
169 | ||
170 | if (xobject->dentry > dentry) | |
171 | _p = &(*_p)->rb_left; | |
172 | else if (xobject->dentry < dentry) | |
173 | _p = &(*_p)->rb_right; | |
174 | else | |
175 | goto wait_for_old_object; | |
176 | } | |
177 | ||
178 | rb_link_node(&object->active_node, _parent, _p); | |
179 | rb_insert_color(&object->active_node, &cache->active_nodes); | |
180 | ||
181 | write_unlock(&cache->active_lock); | |
fee096de DH |
182 | _leave(" = 0"); |
183 | return 0; | |
9ae326a6 DH |
184 | |
185 | /* an old object from a previous incarnation is hogging the slot - we | |
186 | * need to wait for it to be destroyed */ | |
187 | wait_for_old_object: | |
a18feb55 | 188 | trace_cachefiles_wait_active(object, dentry, xobject); |
5ce83d4b | 189 | clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); |
a18feb55 | 190 | |
a30efe26 | 191 | if (fscache_object_is_live(&xobject->fscache)) { |
4e1eb883 | 192 | pr_err("\n"); |
0227d6ab | 193 | pr_err("Error: Unexpected object collision\n"); |
d0e27b78 | 194 | cachefiles_printk_object(object, xobject); |
9ae326a6 DH |
195 | } |
196 | atomic_inc(&xobject->usage); | |
197 | write_unlock(&cache->active_lock); | |
198 | ||
fee096de DH |
199 | if (test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { |
200 | wait_queue_head_t *wq; | |
201 | ||
202 | signed long timeout = 60 * HZ; | |
ac6424b9 | 203 | wait_queue_entry_t wait; |
fee096de DH |
204 | bool requeue; |
205 | ||
206 | /* if the object we're waiting for is queued for processing, | |
207 | * then just put ourselves on the queue behind it */ | |
8b8edefa | 208 | if (work_pending(&xobject->fscache.work)) { |
fee096de DH |
209 | _debug("queue OBJ%x behind OBJ%x immediately", |
210 | object->fscache.debug_id, | |
211 | xobject->fscache.debug_id); | |
212 | goto requeue; | |
213 | } | |
214 | ||
215 | /* otherwise we sleep until either the object we're waiting for | |
8b8edefa | 216 | * is done, or the fscache_object is congested */ |
fee096de DH |
217 | wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE); |
218 | init_wait(&wait); | |
219 | requeue = false; | |
220 | do { | |
221 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
222 | if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) | |
223 | break; | |
8b8edefa TH |
224 | |
225 | requeue = fscache_object_sleep_till_congested(&timeout); | |
fee096de DH |
226 | } while (timeout > 0 && !requeue); |
227 | finish_wait(wq, &wait); | |
228 | ||
229 | if (requeue && | |
230 | test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { | |
231 | _debug("queue OBJ%x behind OBJ%x after wait", | |
232 | object->fscache.debug_id, | |
233 | xobject->fscache.debug_id); | |
234 | goto requeue; | |
235 | } | |
236 | ||
237 | if (timeout <= 0) { | |
4e1eb883 | 238 | pr_err("\n"); |
0227d6ab | 239 | pr_err("Error: Overlong wait for old active object to go away\n"); |
fee096de DH |
240 | cachefiles_printk_object(object, xobject); |
241 | goto requeue; | |
242 | } | |
243 | } | |
244 | ||
245 | ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)); | |
9ae326a6 | 246 | |
b7e768b7 NC |
247 | cache->cache.ops->put_object(&xobject->fscache, |
248 | (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_retry); | |
9ae326a6 | 249 | goto try_again; |
fee096de DH |
250 | |
251 | requeue: | |
b7e768b7 NC |
252 | cache->cache.ops->put_object(&xobject->fscache, |
253 | (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_timeo); | |
fee096de DH |
254 | _leave(" = -ETIMEDOUT"); |
255 | return -ETIMEDOUT; | |
9ae326a6 DH |
256 | } |
257 | ||
a5b3a80b DH |
258 | /* |
259 | * Mark an object as being inactive. | |
260 | */ | |
261 | void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, | |
a818101d DH |
262 | struct cachefiles_object *object, |
263 | blkcnt_t i_blocks) | |
a5b3a80b | 264 | { |
a18feb55 DH |
265 | struct dentry *dentry = object->dentry; |
266 | struct inode *inode = d_backing_inode(dentry); | |
267 | ||
268 | trace_cachefiles_mark_inactive(object, dentry, inode); | |
269 | ||
a5b3a80b DH |
270 | write_lock(&cache->active_lock); |
271 | rb_erase(&object->active_node, &cache->active_nodes); | |
272 | clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); | |
273 | write_unlock(&cache->active_lock); | |
274 | ||
275 | wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE); | |
276 | ||
277 | /* This object can now be culled, so we need to let the daemon know | |
278 | * that there is something it can remove if it needs to. | |
279 | */ | |
db20a892 | 280 | atomic_long_add(i_blocks, &cache->b_released); |
a5b3a80b DH |
281 | if (atomic_inc_return(&cache->f_released)) |
282 | cachefiles_state_changed(cache); | |
283 | } | |
284 | ||
9ae326a6 DH |
285 | /* |
286 | * delete an object representation from the cache | |
287 | * - file backed objects are unlinked | |
288 | * - directory backed objects are stuffed into the graveyard for userspace to | |
289 | * delete | |
290 | * - unlocks the directory mutex | |
291 | */ | |
292 | static int cachefiles_bury_object(struct cachefiles_cache *cache, | |
a18feb55 | 293 | struct cachefiles_object *object, |
9ae326a6 | 294 | struct dentry *dir, |
c61ea31d | 295 | struct dentry *rep, |
182d919b DH |
296 | bool preemptive, |
297 | enum fscache_why_object_killed why) | |
9ae326a6 DH |
298 | { |
299 | struct dentry *grave, *trap; | |
82140443 | 300 | struct path path, path_to_graveyard; |
9ae326a6 DH |
301 | char nbuffer[8 + 8 + 1]; |
302 | int ret; | |
303 | ||
a455589f | 304 | _enter(",'%pd','%pd'", dir, rep); |
9ae326a6 | 305 | |
c61ea31d DH |
306 | _debug("remove %p from %p", rep, dir); |
307 | ||
9ae326a6 | 308 | /* non-directories can just be unlinked */ |
e36cb0b8 | 309 | if (!d_is_dir(rep)) { |
9ae326a6 | 310 | _debug("unlink stale object"); |
9ae326a6 | 311 | |
82140443 DH |
312 | path.mnt = cache->mnt; |
313 | path.dentry = dir; | |
314 | ret = security_path_unlink(&path, rep); | |
315 | if (ret < 0) { | |
316 | cachefiles_io_error(cache, "Unlink security error"); | |
317 | } else { | |
a18feb55 | 318 | trace_cachefiles_unlink(object, rep, why); |
5153bc81 | 319 | ret = vfs_unlink(d_inode(dir), rep, NULL); |
82140443 DH |
320 | |
321 | if (preemptive) | |
182d919b | 322 | cachefiles_mark_object_buried(cache, rep, why); |
82140443 | 323 | } |
c61ea31d | 324 | |
5955102c | 325 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
326 | |
327 | if (ret == -EIO) | |
328 | cachefiles_io_error(cache, "Unlink failed"); | |
329 | ||
330 | _leave(" = %d", ret); | |
331 | return ret; | |
332 | } | |
333 | ||
334 | /* directories have to be moved to the graveyard */ | |
335 | _debug("move stale object to graveyard"); | |
5955102c | 336 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
337 | |
338 | try_again: | |
339 | /* first step is to make up a grave dentry in the graveyard */ | |
340 | sprintf(nbuffer, "%08x%08x", | |
34e06fe4 | 341 | (uint32_t) ktime_get_real_seconds(), |
9ae326a6 DH |
342 | (uint32_t) atomic_inc_return(&cache->gravecounter)); |
343 | ||
344 | /* do the multiway lock magic */ | |
345 | trap = lock_rename(cache->graveyard, dir); | |
346 | ||
347 | /* do some checks before getting the grave dentry */ | |
169b8033 | 348 | if (rep->d_parent != dir || IS_DEADDIR(d_inode(rep))) { |
9ae326a6 DH |
349 | /* the entry was probably culled when we dropped the parent dir |
350 | * lock */ | |
351 | unlock_rename(cache->graveyard, dir); | |
352 | _leave(" = 0 [culled?]"); | |
353 | return 0; | |
354 | } | |
355 | ||
ce40fa78 | 356 | if (!d_can_lookup(cache->graveyard)) { |
9ae326a6 DH |
357 | unlock_rename(cache->graveyard, dir); |
358 | cachefiles_io_error(cache, "Graveyard no longer a directory"); | |
359 | return -EIO; | |
360 | } | |
361 | ||
362 | if (trap == rep) { | |
363 | unlock_rename(cache->graveyard, dir); | |
364 | cachefiles_io_error(cache, "May not make directory loop"); | |
365 | return -EIO; | |
366 | } | |
367 | ||
368 | if (d_mountpoint(rep)) { | |
369 | unlock_rename(cache->graveyard, dir); | |
370 | cachefiles_io_error(cache, "Mountpoint in cache"); | |
371 | return -EIO; | |
372 | } | |
373 | ||
374 | grave = lookup_one_len(nbuffer, cache->graveyard, strlen(nbuffer)); | |
375 | if (IS_ERR(grave)) { | |
376 | unlock_rename(cache->graveyard, dir); | |
377 | ||
378 | if (PTR_ERR(grave) == -ENOMEM) { | |
379 | _leave(" = -ENOMEM"); | |
380 | return -ENOMEM; | |
381 | } | |
382 | ||
383 | cachefiles_io_error(cache, "Lookup error %ld", | |
384 | PTR_ERR(grave)); | |
385 | return -EIO; | |
386 | } | |
387 | ||
466b77bc | 388 | if (d_is_positive(grave)) { |
9ae326a6 DH |
389 | unlock_rename(cache->graveyard, dir); |
390 | dput(grave); | |
391 | grave = NULL; | |
392 | cond_resched(); | |
393 | goto try_again; | |
394 | } | |
395 | ||
396 | if (d_mountpoint(grave)) { | |
397 | unlock_rename(cache->graveyard, dir); | |
398 | dput(grave); | |
399 | cachefiles_io_error(cache, "Mountpoint in graveyard"); | |
400 | return -EIO; | |
401 | } | |
402 | ||
403 | /* target should not be an ancestor of source */ | |
404 | if (trap == grave) { | |
405 | unlock_rename(cache->graveyard, dir); | |
406 | dput(grave); | |
407 | cachefiles_io_error(cache, "May not make directory loop"); | |
408 | return -EIO; | |
409 | } | |
410 | ||
411 | /* attempt the rename */ | |
82140443 DH |
412 | path.mnt = cache->mnt; |
413 | path.dentry = dir; | |
414 | path_to_graveyard.mnt = cache->mnt; | |
415 | path_to_graveyard.dentry = cache->graveyard; | |
0b3974eb | 416 | ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0); |
82140443 DH |
417 | if (ret < 0) { |
418 | cachefiles_io_error(cache, "Rename security error %d", ret); | |
419 | } else { | |
a18feb55 | 420 | trace_cachefiles_rename(object, rep, grave, why); |
5153bc81 DH |
421 | ret = vfs_rename(d_inode(dir), rep, |
422 | d_inode(cache->graveyard), grave, NULL, 0); | |
82140443 DH |
423 | if (ret != 0 && ret != -ENOMEM) |
424 | cachefiles_io_error(cache, | |
425 | "Rename failed with error %d", ret); | |
9ae326a6 | 426 | |
82140443 | 427 | if (preemptive) |
182d919b | 428 | cachefiles_mark_object_buried(cache, rep, why); |
82140443 | 429 | } |
c61ea31d | 430 | |
9ae326a6 DH |
431 | unlock_rename(cache->graveyard, dir); |
432 | dput(grave); | |
433 | _leave(" = 0"); | |
434 | return 0; | |
435 | } | |
436 | ||
437 | /* | |
438 | * delete an object representation from the cache | |
439 | */ | |
440 | int cachefiles_delete_object(struct cachefiles_cache *cache, | |
441 | struct cachefiles_object *object) | |
442 | { | |
443 | struct dentry *dir; | |
444 | int ret; | |
445 | ||
c61ea31d | 446 | _enter(",OBJ%x{%p}", object->fscache.debug_id, object->dentry); |
9ae326a6 DH |
447 | |
448 | ASSERT(object->dentry); | |
466b77bc | 449 | ASSERT(d_backing_inode(object->dentry)); |
9ae326a6 DH |
450 | ASSERT(object->dentry->d_parent); |
451 | ||
452 | dir = dget_parent(object->dentry); | |
453 | ||
5955102c | 454 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
8f9941ae | 455 | |
182d919b | 456 | if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) { |
c61ea31d DH |
457 | /* object allocation for the same key preemptively deleted this |
458 | * object's file so that it could create its own file */ | |
459 | _debug("object preemptively buried"); | |
5955102c | 460 | inode_unlock(d_inode(dir)); |
8f9941ae | 461 | ret = 0; |
c61ea31d DH |
462 | } else { |
463 | /* we need to check that our parent is _still_ our parent - it | |
464 | * may have been renamed */ | |
465 | if (dir == object->dentry->d_parent) { | |
a18feb55 | 466 | ret = cachefiles_bury_object(cache, object, dir, |
182d919b DH |
467 | object->dentry, false, |
468 | FSCACHE_OBJECT_WAS_RETIRED); | |
c61ea31d DH |
469 | } else { |
470 | /* it got moved, presumably by cachefilesd culling it, | |
471 | * so it's no longer in the key path and we can ignore | |
472 | * it */ | |
5955102c | 473 | inode_unlock(d_inode(dir)); |
c61ea31d DH |
474 | ret = 0; |
475 | } | |
8f9941ae | 476 | } |
9ae326a6 DH |
477 | |
478 | dput(dir); | |
479 | _leave(" = %d", ret); | |
480 | return ret; | |
481 | } | |
482 | ||
483 | /* | |
484 | * walk from the parent object to the child object through the backing | |
485 | * filesystem, creating directories as we go | |
486 | */ | |
487 | int cachefiles_walk_to_object(struct cachefiles_object *parent, | |
488 | struct cachefiles_object *object, | |
489 | const char *key, | |
490 | struct cachefiles_xattr *auxdata) | |
491 | { | |
492 | struct cachefiles_cache *cache; | |
493 | struct dentry *dir, *next = NULL; | |
a18feb55 | 494 | struct inode *inode; |
82140443 | 495 | struct path path; |
9ae326a6 DH |
496 | unsigned long start; |
497 | const char *name; | |
498 | int ret, nlen; | |
499 | ||
c61ea31d DH |
500 | _enter("OBJ%x{%p},OBJ%x,%s,", |
501 | parent->fscache.debug_id, parent->dentry, | |
502 | object->fscache.debug_id, key); | |
9ae326a6 DH |
503 | |
504 | cache = container_of(parent->fscache.cache, | |
505 | struct cachefiles_cache, cache); | |
82140443 | 506 | path.mnt = cache->mnt; |
9ae326a6 DH |
507 | |
508 | ASSERT(parent->dentry); | |
466b77bc | 509 | ASSERT(d_backing_inode(parent->dentry)); |
9ae326a6 | 510 | |
e36cb0b8 | 511 | if (!(d_is_dir(parent->dentry))) { |
9ae326a6 DH |
512 | // TODO: convert file to dir |
513 | _leave("looking up in none directory"); | |
514 | return -ENOBUFS; | |
515 | } | |
516 | ||
517 | dir = dget(parent->dentry); | |
518 | ||
519 | advance: | |
520 | /* attempt to transit the first directory component */ | |
521 | name = key; | |
522 | nlen = strlen(key); | |
523 | ||
524 | /* key ends in a double NUL */ | |
525 | key = key + nlen + 1; | |
526 | if (!*key) | |
527 | key = NULL; | |
528 | ||
529 | lookup_again: | |
530 | /* search the current directory for the element name */ | |
531 | _debug("lookup '%s'", name); | |
532 | ||
5955102c | 533 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
9ae326a6 DH |
534 | |
535 | start = jiffies; | |
536 | next = lookup_one_len(name, dir, nlen); | |
537 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
a18feb55 DH |
538 | if (IS_ERR(next)) { |
539 | trace_cachefiles_lookup(object, next, NULL); | |
9ae326a6 | 540 | goto lookup_error; |
a18feb55 | 541 | } |
9ae326a6 | 542 | |
a18feb55 DH |
543 | inode = d_backing_inode(next); |
544 | trace_cachefiles_lookup(object, next, inode); | |
545 | _debug("next -> %p %s", next, inode ? "positive" : "negative"); | |
9ae326a6 DH |
546 | |
547 | if (!key) | |
a18feb55 | 548 | object->new = !inode; |
9ae326a6 DH |
549 | |
550 | /* if this element of the path doesn't exist, then the lookup phase | |
551 | * failed, and we can release any readers in the certain knowledge that | |
552 | * there's nothing for them to actually read */ | |
466b77bc | 553 | if (d_is_negative(next)) |
9ae326a6 DH |
554 | fscache_object_lookup_negative(&object->fscache); |
555 | ||
556 | /* we need to create the object if it's negative */ | |
557 | if (key || object->type == FSCACHE_COOKIE_TYPE_INDEX) { | |
558 | /* index objects and intervening tree levels must be subdirs */ | |
466b77bc | 559 | if (d_is_negative(next)) { |
9ae326a6 DH |
560 | ret = cachefiles_has_space(cache, 1, 0); |
561 | if (ret < 0) | |
182d919b | 562 | goto no_space_error; |
9ae326a6 | 563 | |
82140443 DH |
564 | path.dentry = dir; |
565 | ret = security_path_mkdir(&path, next, 0); | |
566 | if (ret < 0) | |
567 | goto create_error; | |
9ae326a6 | 568 | start = jiffies; |
5153bc81 | 569 | ret = vfs_mkdir(d_inode(dir), next, 0); |
9ae326a6 | 570 | cachefiles_hist(cachefiles_mkdir_histogram, start); |
a18feb55 DH |
571 | if (!key) |
572 | trace_cachefiles_mkdir(object, next, ret); | |
9ae326a6 DH |
573 | if (ret < 0) |
574 | goto create_error; | |
575 | ||
9c3e9025 AV |
576 | if (unlikely(d_unhashed(next))) { |
577 | dput(next); | |
578 | inode_unlock(d_inode(dir)); | |
579 | goto lookup_again; | |
580 | } | |
466b77bc | 581 | ASSERT(d_backing_inode(next)); |
9ae326a6 DH |
582 | |
583 | _debug("mkdir -> %p{%p{ino=%lu}}", | |
466b77bc | 584 | next, d_backing_inode(next), d_backing_inode(next)->i_ino); |
9ae326a6 | 585 | |
ce40fa78 | 586 | } else if (!d_can_lookup(next)) { |
6ff66ac7 | 587 | pr_err("inode %lu is not a directory\n", |
466b77bc | 588 | d_backing_inode(next)->i_ino); |
9ae326a6 DH |
589 | ret = -ENOBUFS; |
590 | goto error; | |
591 | } | |
592 | ||
593 | } else { | |
594 | /* non-index objects start out life as files */ | |
466b77bc | 595 | if (d_is_negative(next)) { |
9ae326a6 DH |
596 | ret = cachefiles_has_space(cache, 1, 0); |
597 | if (ret < 0) | |
182d919b | 598 | goto no_space_error; |
9ae326a6 | 599 | |
82140443 DH |
600 | path.dentry = dir; |
601 | ret = security_path_mknod(&path, next, S_IFREG, 0); | |
602 | if (ret < 0) | |
603 | goto create_error; | |
9ae326a6 | 604 | start = jiffies; |
5153bc81 | 605 | ret = vfs_create(d_inode(dir), next, S_IFREG, true); |
9ae326a6 | 606 | cachefiles_hist(cachefiles_create_histogram, start); |
a18feb55 | 607 | trace_cachefiles_create(object, next, ret); |
9ae326a6 DH |
608 | if (ret < 0) |
609 | goto create_error; | |
610 | ||
466b77bc | 611 | ASSERT(d_backing_inode(next)); |
9ae326a6 DH |
612 | |
613 | _debug("create -> %p{%p{ino=%lu}}", | |
466b77bc | 614 | next, d_backing_inode(next), d_backing_inode(next)->i_ino); |
9ae326a6 | 615 | |
ce40fa78 | 616 | } else if (!d_can_lookup(next) && |
e36cb0b8 | 617 | !d_is_reg(next) |
9ae326a6 | 618 | ) { |
6ff66ac7 | 619 | pr_err("inode %lu is not a file or directory\n", |
466b77bc | 620 | d_backing_inode(next)->i_ino); |
9ae326a6 DH |
621 | ret = -ENOBUFS; |
622 | goto error; | |
623 | } | |
624 | } | |
625 | ||
626 | /* process the next component */ | |
627 | if (key) { | |
628 | _debug("advance"); | |
5955102c | 629 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
630 | dput(dir); |
631 | dir = next; | |
632 | next = NULL; | |
633 | goto advance; | |
634 | } | |
635 | ||
636 | /* we've found the object we were looking for */ | |
637 | object->dentry = next; | |
638 | ||
639 | /* if we've found that the terminal object exists, then we need to | |
640 | * check its attributes and delete it if it's out of date */ | |
641 | if (!object->new) { | |
a455589f | 642 | _debug("validate '%pd'", next); |
9ae326a6 DH |
643 | |
644 | ret = cachefiles_check_object_xattr(object, auxdata); | |
645 | if (ret == -ESTALE) { | |
646 | /* delete the object (the deleter drops the directory | |
647 | * mutex) */ | |
648 | object->dentry = NULL; | |
649 | ||
a18feb55 DH |
650 | ret = cachefiles_bury_object(cache, object, dir, next, |
651 | true, | |
182d919b | 652 | FSCACHE_OBJECT_IS_STALE); |
9ae326a6 DH |
653 | dput(next); |
654 | next = NULL; | |
655 | ||
656 | if (ret < 0) | |
657 | goto delete_error; | |
658 | ||
659 | _debug("redo lookup"); | |
182d919b | 660 | fscache_object_retrying_stale(&object->fscache); |
9ae326a6 DH |
661 | goto lookup_again; |
662 | } | |
663 | } | |
664 | ||
665 | /* note that we're now using this object */ | |
fee096de | 666 | ret = cachefiles_mark_object_active(cache, object); |
9ae326a6 | 667 | |
5955102c | 668 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
669 | dput(dir); |
670 | dir = NULL; | |
671 | ||
fee096de DH |
672 | if (ret == -ETIMEDOUT) |
673 | goto mark_active_timed_out; | |
674 | ||
9ae326a6 DH |
675 | _debug("=== OBTAINED_OBJECT ==="); |
676 | ||
677 | if (object->new) { | |
678 | /* attach data to a newly constructed terminal object */ | |
679 | ret = cachefiles_set_object_xattr(object, auxdata); | |
680 | if (ret < 0) | |
681 | goto check_error; | |
682 | } else { | |
683 | /* always update the atime on an object we've just looked up | |
684 | * (this is used to keep track of culling, and atimes are only | |
685 | * updated by read, write and readdir but not lookup or | |
686 | * open) */ | |
68ac1234 AV |
687 | path.dentry = next; |
688 | touch_atime(&path); | |
9ae326a6 DH |
689 | } |
690 | ||
691 | /* open a file interface onto a data file */ | |
692 | if (object->type != FSCACHE_COOKIE_TYPE_INDEX) { | |
e36cb0b8 | 693 | if (d_is_reg(object->dentry)) { |
9ae326a6 DH |
694 | const struct address_space_operations *aops; |
695 | ||
696 | ret = -EPERM; | |
466b77bc | 697 | aops = d_backing_inode(object->dentry)->i_mapping->a_ops; |
9ae326a6 DH |
698 | if (!aops->bmap) |
699 | goto check_error; | |
95201a40 N |
700 | if (object->dentry->d_sb->s_blocksize > PAGE_SIZE) |
701 | goto check_error; | |
9ae326a6 DH |
702 | |
703 | object->backer = object->dentry; | |
704 | } else { | |
705 | BUG(); // TODO: open file in data-class subdir | |
706 | } | |
707 | } | |
708 | ||
709 | object->new = 0; | |
710 | fscache_obtained_object(&object->fscache); | |
711 | ||
466b77bc | 712 | _leave(" = 0 [%lu]", d_backing_inode(object->dentry)->i_ino); |
9ae326a6 DH |
713 | return 0; |
714 | ||
182d919b DH |
715 | no_space_error: |
716 | fscache_object_mark_killed(&object->fscache, FSCACHE_OBJECT_NO_SPACE); | |
9ae326a6 DH |
717 | create_error: |
718 | _debug("create error %d", ret); | |
719 | if (ret == -EIO) | |
720 | cachefiles_io_error(cache, "Create/mkdir failed"); | |
721 | goto error; | |
722 | ||
fee096de DH |
723 | mark_active_timed_out: |
724 | _debug("mark active timed out"); | |
725 | goto release_dentry; | |
726 | ||
9ae326a6 DH |
727 | check_error: |
728 | _debug("check error %d", ret); | |
a818101d DH |
729 | cachefiles_mark_object_inactive( |
730 | cache, object, d_backing_inode(object->dentry)->i_blocks); | |
fee096de | 731 | release_dentry: |
9ae326a6 DH |
732 | dput(object->dentry); |
733 | object->dentry = NULL; | |
734 | goto error_out; | |
735 | ||
736 | delete_error: | |
737 | _debug("delete error %d", ret); | |
738 | goto error_out2; | |
739 | ||
740 | lookup_error: | |
741 | _debug("lookup error %ld", PTR_ERR(next)); | |
742 | ret = PTR_ERR(next); | |
743 | if (ret == -EIO) | |
744 | cachefiles_io_error(cache, "Lookup failed"); | |
745 | next = NULL; | |
746 | error: | |
5955102c | 747 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
748 | dput(next); |
749 | error_out2: | |
750 | dput(dir); | |
751 | error_out: | |
9ae326a6 DH |
752 | _leave(" = error %d", -ret); |
753 | return ret; | |
754 | } | |
755 | ||
756 | /* | |
757 | * get a subdirectory | |
758 | */ | |
759 | struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, | |
760 | struct dentry *dir, | |
761 | const char *dirname) | |
762 | { | |
763 | struct dentry *subdir; | |
764 | unsigned long start; | |
82140443 | 765 | struct path path; |
9ae326a6 DH |
766 | int ret; |
767 | ||
768 | _enter(",,%s", dirname); | |
769 | ||
770 | /* search the current directory for the element name */ | |
5955102c | 771 | inode_lock(d_inode(dir)); |
9ae326a6 | 772 | |
9c3e9025 | 773 | retry: |
9ae326a6 DH |
774 | start = jiffies; |
775 | subdir = lookup_one_len(dirname, dir, strlen(dirname)); | |
776 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
777 | if (IS_ERR(subdir)) { | |
778 | if (PTR_ERR(subdir) == -ENOMEM) | |
779 | goto nomem_d_alloc; | |
780 | goto lookup_error; | |
781 | } | |
782 | ||
783 | _debug("subdir -> %p %s", | |
466b77bc | 784 | subdir, d_backing_inode(subdir) ? "positive" : "negative"); |
9ae326a6 DH |
785 | |
786 | /* we need to create the subdir if it doesn't exist yet */ | |
466b77bc | 787 | if (d_is_negative(subdir)) { |
9ae326a6 DH |
788 | ret = cachefiles_has_space(cache, 1, 0); |
789 | if (ret < 0) | |
790 | goto mkdir_error; | |
791 | ||
792 | _debug("attempt mkdir"); | |
793 | ||
82140443 DH |
794 | path.mnt = cache->mnt; |
795 | path.dentry = dir; | |
796 | ret = security_path_mkdir(&path, subdir, 0700); | |
797 | if (ret < 0) | |
798 | goto mkdir_error; | |
5153bc81 | 799 | ret = vfs_mkdir(d_inode(dir), subdir, 0700); |
9ae326a6 DH |
800 | if (ret < 0) |
801 | goto mkdir_error; | |
802 | ||
9c3e9025 AV |
803 | if (unlikely(d_unhashed(subdir))) { |
804 | dput(subdir); | |
805 | goto retry; | |
806 | } | |
466b77bc | 807 | ASSERT(d_backing_inode(subdir)); |
9ae326a6 DH |
808 | |
809 | _debug("mkdir -> %p{%p{ino=%lu}}", | |
810 | subdir, | |
466b77bc DH |
811 | d_backing_inode(subdir), |
812 | d_backing_inode(subdir)->i_ino); | |
9ae326a6 DH |
813 | } |
814 | ||
5955102c | 815 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
816 | |
817 | /* we need to make sure the subdir is a directory */ | |
466b77bc | 818 | ASSERT(d_backing_inode(subdir)); |
9ae326a6 | 819 | |
ce40fa78 | 820 | if (!d_can_lookup(subdir)) { |
6ff66ac7 | 821 | pr_err("%s is not a directory\n", dirname); |
9ae326a6 DH |
822 | ret = -EIO; |
823 | goto check_error; | |
824 | } | |
825 | ||
826 | ret = -EPERM; | |
5d6c3191 | 827 | if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) || |
466b77bc DH |
828 | !d_backing_inode(subdir)->i_op->lookup || |
829 | !d_backing_inode(subdir)->i_op->mkdir || | |
830 | !d_backing_inode(subdir)->i_op->create || | |
2773bf00 | 831 | !d_backing_inode(subdir)->i_op->rename || |
466b77bc DH |
832 | !d_backing_inode(subdir)->i_op->rmdir || |
833 | !d_backing_inode(subdir)->i_op->unlink) | |
9ae326a6 DH |
834 | goto check_error; |
835 | ||
466b77bc | 836 | _leave(" = [%lu]", d_backing_inode(subdir)->i_ino); |
9ae326a6 DH |
837 | return subdir; |
838 | ||
839 | check_error: | |
840 | dput(subdir); | |
841 | _leave(" = %d [check]", ret); | |
842 | return ERR_PTR(ret); | |
843 | ||
844 | mkdir_error: | |
5955102c | 845 | inode_unlock(d_inode(dir)); |
9ae326a6 | 846 | dput(subdir); |
6ff66ac7 | 847 | pr_err("mkdir %s failed with error %d\n", dirname, ret); |
9ae326a6 DH |
848 | return ERR_PTR(ret); |
849 | ||
850 | lookup_error: | |
5955102c | 851 | inode_unlock(d_inode(dir)); |
9ae326a6 | 852 | ret = PTR_ERR(subdir); |
6ff66ac7 | 853 | pr_err("Lookup %s failed with error %d\n", dirname, ret); |
9ae326a6 DH |
854 | return ERR_PTR(ret); |
855 | ||
856 | nomem_d_alloc: | |
5955102c | 857 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
858 | _leave(" = -ENOMEM"); |
859 | return ERR_PTR(-ENOMEM); | |
860 | } | |
861 | ||
862 | /* | |
863 | * find out if an object is in use or not | |
864 | * - if finds object and it's not in use: | |
865 | * - returns a pointer to the object and a reference on it | |
866 | * - returns with the directory locked | |
867 | */ | |
868 | static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache, | |
869 | struct dentry *dir, | |
870 | char *filename) | |
871 | { | |
872 | struct cachefiles_object *object; | |
873 | struct rb_node *_n; | |
874 | struct dentry *victim; | |
875 | unsigned long start; | |
876 | int ret; | |
877 | ||
a455589f AV |
878 | //_enter(",%pd/,%s", |
879 | // dir, filename); | |
9ae326a6 DH |
880 | |
881 | /* look up the victim */ | |
5955102c | 882 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
9ae326a6 DH |
883 | |
884 | start = jiffies; | |
885 | victim = lookup_one_len(filename, dir, strlen(filename)); | |
886 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
887 | if (IS_ERR(victim)) | |
888 | goto lookup_error; | |
889 | ||
890 | //_debug("victim -> %p %s", | |
466b77bc | 891 | // victim, d_backing_inode(victim) ? "positive" : "negative"); |
9ae326a6 DH |
892 | |
893 | /* if the object is no longer there then we probably retired the object | |
894 | * at the netfs's request whilst the cull was in progress | |
895 | */ | |
466b77bc | 896 | if (d_is_negative(victim)) { |
5955102c | 897 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
898 | dput(victim); |
899 | _leave(" = -ENOENT [absent]"); | |
900 | return ERR_PTR(-ENOENT); | |
901 | } | |
902 | ||
903 | /* check to see if we're using this object */ | |
904 | read_lock(&cache->active_lock); | |
905 | ||
906 | _n = cache->active_nodes.rb_node; | |
907 | ||
908 | while (_n) { | |
909 | object = rb_entry(_n, struct cachefiles_object, active_node); | |
910 | ||
911 | if (object->dentry > victim) | |
912 | _n = _n->rb_left; | |
913 | else if (object->dentry < victim) | |
914 | _n = _n->rb_right; | |
915 | else | |
916 | goto object_in_use; | |
917 | } | |
918 | ||
919 | read_unlock(&cache->active_lock); | |
920 | ||
921 | //_leave(" = %p", victim); | |
922 | return victim; | |
923 | ||
924 | object_in_use: | |
925 | read_unlock(&cache->active_lock); | |
5955102c | 926 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
927 | dput(victim); |
928 | //_leave(" = -EBUSY [in use]"); | |
929 | return ERR_PTR(-EBUSY); | |
930 | ||
931 | lookup_error: | |
5955102c | 932 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
933 | ret = PTR_ERR(victim); |
934 | if (ret == -ENOENT) { | |
935 | /* file or dir now absent - probably retired by netfs */ | |
936 | _leave(" = -ESTALE [absent]"); | |
937 | return ERR_PTR(-ESTALE); | |
938 | } | |
939 | ||
940 | if (ret == -EIO) { | |
941 | cachefiles_io_error(cache, "Lookup failed"); | |
942 | } else if (ret != -ENOMEM) { | |
6ff66ac7 | 943 | pr_err("Internal error: %d\n", ret); |
9ae326a6 DH |
944 | ret = -EIO; |
945 | } | |
946 | ||
947 | _leave(" = %d", ret); | |
948 | return ERR_PTR(ret); | |
949 | } | |
950 | ||
951 | /* | |
952 | * cull an object if it's not in use | |
953 | * - called only by cache manager daemon | |
954 | */ | |
955 | int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, | |
956 | char *filename) | |
957 | { | |
958 | struct dentry *victim; | |
959 | int ret; | |
960 | ||
a455589f | 961 | _enter(",%pd/,%s", dir, filename); |
9ae326a6 DH |
962 | |
963 | victim = cachefiles_check_active(cache, dir, filename); | |
964 | if (IS_ERR(victim)) | |
965 | return PTR_ERR(victim); | |
966 | ||
967 | _debug("victim -> %p %s", | |
466b77bc | 968 | victim, d_backing_inode(victim) ? "positive" : "negative"); |
9ae326a6 DH |
969 | |
970 | /* okay... the victim is not being used so we can cull it | |
971 | * - start by marking it as stale | |
972 | */ | |
973 | _debug("victim is cullable"); | |
974 | ||
975 | ret = cachefiles_remove_object_xattr(cache, victim); | |
976 | if (ret < 0) | |
977 | goto error_unlock; | |
978 | ||
979 | /* actually remove the victim (drops the dir mutex) */ | |
980 | _debug("bury"); | |
981 | ||
a18feb55 | 982 | ret = cachefiles_bury_object(cache, NULL, dir, victim, false, |
182d919b | 983 | FSCACHE_OBJECT_WAS_CULLED); |
9ae326a6 DH |
984 | if (ret < 0) |
985 | goto error; | |
986 | ||
987 | dput(victim); | |
988 | _leave(" = 0"); | |
989 | return 0; | |
990 | ||
991 | error_unlock: | |
5955102c | 992 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
993 | error: |
994 | dput(victim); | |
995 | if (ret == -ENOENT) { | |
996 | /* file or dir now absent - probably retired by netfs */ | |
997 | _leave(" = -ESTALE [absent]"); | |
998 | return -ESTALE; | |
999 | } | |
1000 | ||
1001 | if (ret != -ENOMEM) { | |
6ff66ac7 | 1002 | pr_err("Internal error: %d\n", ret); |
9ae326a6 DH |
1003 | ret = -EIO; |
1004 | } | |
1005 | ||
1006 | _leave(" = %d", ret); | |
1007 | return ret; | |
1008 | } | |
1009 | ||
1010 | /* | |
1011 | * find out if an object is in use or not | |
1012 | * - called only by cache manager daemon | |
1013 | * - returns -EBUSY or 0 to indicate whether an object is in use or not | |
1014 | */ | |
1015 | int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir, | |
1016 | char *filename) | |
1017 | { | |
1018 | struct dentry *victim; | |
1019 | ||
a455589f AV |
1020 | //_enter(",%pd/,%s", |
1021 | // dir, filename); | |
9ae326a6 DH |
1022 | |
1023 | victim = cachefiles_check_active(cache, dir, filename); | |
1024 | if (IS_ERR(victim)) | |
1025 | return PTR_ERR(victim); | |
1026 | ||
5955102c | 1027 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
1028 | dput(victim); |
1029 | //_leave(" = 0"); | |
1030 | return 0; | |
1031 | } |