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b4d0d230 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
9ae326a6 DH |
2 | /* CacheFiles path walking and related routines |
3 | * | |
4 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
9ae326a6 DH |
6 | */ |
7 | ||
8 | #include <linux/module.h> | |
9 | #include <linux/sched.h> | |
10 | #include <linux/file.h> | |
11 | #include <linux/fs.h> | |
12 | #include <linux/fsnotify.h> | |
13 | #include <linux/quotaops.h> | |
14 | #include <linux/xattr.h> | |
15 | #include <linux/mount.h> | |
16 | #include <linux/namei.h> | |
17 | #include <linux/security.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
9ae326a6 DH |
19 | #include "internal.h" |
20 | ||
d0e27b78 DH |
21 | #define CACHEFILES_KEYBUF_SIZE 512 |
22 | ||
23 | /* | |
24 | * dump debugging info about an object | |
25 | */ | |
26 | static noinline | |
27 | void __cachefiles_printk_object(struct cachefiles_object *object, | |
402cb8dd | 28 | const char *prefix) |
d0e27b78 DH |
29 | { |
30 | struct fscache_cookie *cookie; | |
402cb8dd DH |
31 | const u8 *k; |
32 | unsigned loop; | |
d0e27b78 | 33 | |
4e1eb883 FF |
34 | pr_err("%sobject: OBJ%x\n", prefix, object->fscache.debug_id); |
35 | pr_err("%sobjstate=%s fl=%lx wbusy=%x ev=%lx[%lx]\n", | |
caaef690 | 36 | prefix, object->fscache.state->name, |
8b8edefa | 37 | object->fscache.flags, work_busy(&object->fscache.work), |
c2d35bfe | 38 | object->fscache.events, object->fscache.event_mask); |
4e1eb883 | 39 | pr_err("%sops=%u inp=%u exc=%u\n", |
d0e27b78 DH |
40 | prefix, object->fscache.n_ops, object->fscache.n_in_progress, |
41 | object->fscache.n_exclusive); | |
4e1eb883 | 42 | pr_err("%sparent=%p\n", |
d0e27b78 DH |
43 | prefix, object->fscache.parent); |
44 | ||
45 | spin_lock(&object->fscache.lock); | |
46 | cookie = object->fscache.cookie; | |
47 | if (cookie) { | |
4e1eb883 | 48 | pr_err("%scookie=%p [pr=%p nd=%p fl=%lx]\n", |
d0e27b78 DH |
49 | prefix, |
50 | object->fscache.cookie, | |
51 | object->fscache.cookie->parent, | |
52 | object->fscache.cookie->netfs_data, | |
53 | object->fscache.cookie->flags); | |
402cb8dd DH |
54 | pr_err("%skey=[%u] '", prefix, cookie->key_len); |
55 | k = (cookie->key_len <= sizeof(cookie->inline_key)) ? | |
56 | cookie->inline_key : cookie->key; | |
57 | for (loop = 0; loop < cookie->key_len; loop++) | |
58 | pr_cont("%02x", k[loop]); | |
59 | pr_cont("'\n"); | |
d0e27b78 | 60 | } else { |
4e1eb883 | 61 | pr_err("%scookie=NULL\n", prefix); |
d0e27b78 DH |
62 | } |
63 | spin_unlock(&object->fscache.lock); | |
d0e27b78 DH |
64 | } |
65 | ||
66 | /* | |
67 | * dump debugging info about a pair of objects | |
68 | */ | |
69 | static noinline void cachefiles_printk_object(struct cachefiles_object *object, | |
70 | struct cachefiles_object *xobject) | |
71 | { | |
d0e27b78 | 72 | if (object) |
402cb8dd | 73 | __cachefiles_printk_object(object, ""); |
d0e27b78 | 74 | if (xobject) |
402cb8dd | 75 | __cachefiles_printk_object(xobject, "x"); |
d0e27b78 DH |
76 | } |
77 | ||
c61ea31d DH |
78 | /* |
79 | * mark the owner of a dentry, if there is one, to indicate that that dentry | |
80 | * has been preemptively deleted | |
81 | * - the caller must hold the i_mutex on the dentry's parent as required to | |
82 | * call vfs_unlink(), vfs_rmdir() or vfs_rename() | |
83 | */ | |
84 | static void cachefiles_mark_object_buried(struct cachefiles_cache *cache, | |
182d919b DH |
85 | struct dentry *dentry, |
86 | enum fscache_why_object_killed why) | |
c61ea31d DH |
87 | { |
88 | struct cachefiles_object *object; | |
89 | struct rb_node *p; | |
90 | ||
a455589f | 91 | _enter(",'%pd'", dentry); |
c61ea31d DH |
92 | |
93 | write_lock(&cache->active_lock); | |
94 | ||
95 | p = cache->active_nodes.rb_node; | |
96 | while (p) { | |
97 | object = rb_entry(p, struct cachefiles_object, active_node); | |
98 | if (object->dentry > dentry) | |
99 | p = p->rb_left; | |
100 | else if (object->dentry < dentry) | |
101 | p = p->rb_right; | |
102 | else | |
103 | goto found_dentry; | |
104 | } | |
105 | ||
106 | write_unlock(&cache->active_lock); | |
a18feb55 | 107 | trace_cachefiles_mark_buried(NULL, dentry, why); |
c61ea31d DH |
108 | _leave(" [no owner]"); |
109 | return; | |
110 | ||
111 | /* found the dentry for */ | |
112 | found_dentry: | |
113 | kdebug("preemptive burial: OBJ%x [%s] %p", | |
114 | object->fscache.debug_id, | |
caaef690 | 115 | object->fscache.state->name, |
c61ea31d DH |
116 | dentry); |
117 | ||
a18feb55 DH |
118 | trace_cachefiles_mark_buried(object, dentry, why); |
119 | ||
493f7bc1 | 120 | if (fscache_object_is_live(&object->fscache)) { |
4e1eb883 | 121 | pr_err("\n"); |
0227d6ab | 122 | pr_err("Error: Can't preemptively bury live object\n"); |
c61ea31d | 123 | cachefiles_printk_object(object, NULL); |
182d919b DH |
124 | } else { |
125 | if (why != FSCACHE_OBJECT_IS_STALE) | |
126 | fscache_object_mark_killed(&object->fscache, why); | |
c61ea31d DH |
127 | } |
128 | ||
129 | write_unlock(&cache->active_lock); | |
130 | _leave(" [owner marked]"); | |
131 | } | |
132 | ||
9ae326a6 DH |
133 | /* |
134 | * record the fact that an object is now active | |
135 | */ | |
fee096de DH |
136 | static int cachefiles_mark_object_active(struct cachefiles_cache *cache, |
137 | struct cachefiles_object *object) | |
9ae326a6 DH |
138 | { |
139 | struct cachefiles_object *xobject; | |
140 | struct rb_node **_p, *_parent = NULL; | |
141 | struct dentry *dentry; | |
142 | ||
143 | _enter(",%p", object); | |
144 | ||
145 | try_again: | |
146 | write_lock(&cache->active_lock); | |
147 | ||
a18feb55 DH |
148 | dentry = object->dentry; |
149 | trace_cachefiles_mark_active(object, dentry); | |
150 | ||
d0e27b78 | 151 | if (test_and_set_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) { |
0227d6ab | 152 | pr_err("Error: Object already active\n"); |
d0e27b78 | 153 | cachefiles_printk_object(object, NULL); |
9ae326a6 | 154 | BUG(); |
d0e27b78 | 155 | } |
9ae326a6 | 156 | |
9ae326a6 DH |
157 | _p = &cache->active_nodes.rb_node; |
158 | while (*_p) { | |
159 | _parent = *_p; | |
160 | xobject = rb_entry(_parent, | |
161 | struct cachefiles_object, active_node); | |
162 | ||
163 | ASSERT(xobject != object); | |
164 | ||
165 | if (xobject->dentry > dentry) | |
166 | _p = &(*_p)->rb_left; | |
167 | else if (xobject->dentry < dentry) | |
168 | _p = &(*_p)->rb_right; | |
169 | else | |
170 | goto wait_for_old_object; | |
171 | } | |
172 | ||
173 | rb_link_node(&object->active_node, _parent, _p); | |
174 | rb_insert_color(&object->active_node, &cache->active_nodes); | |
175 | ||
176 | write_unlock(&cache->active_lock); | |
fee096de DH |
177 | _leave(" = 0"); |
178 | return 0; | |
9ae326a6 DH |
179 | |
180 | /* an old object from a previous incarnation is hogging the slot - we | |
181 | * need to wait for it to be destroyed */ | |
182 | wait_for_old_object: | |
a18feb55 | 183 | trace_cachefiles_wait_active(object, dentry, xobject); |
5ce83d4b | 184 | clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); |
a18feb55 | 185 | |
a30efe26 | 186 | if (fscache_object_is_live(&xobject->fscache)) { |
4e1eb883 | 187 | pr_err("\n"); |
0227d6ab | 188 | pr_err("Error: Unexpected object collision\n"); |
d0e27b78 | 189 | cachefiles_printk_object(object, xobject); |
9ae326a6 DH |
190 | } |
191 | atomic_inc(&xobject->usage); | |
192 | write_unlock(&cache->active_lock); | |
193 | ||
fee096de DH |
194 | if (test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { |
195 | wait_queue_head_t *wq; | |
196 | ||
197 | signed long timeout = 60 * HZ; | |
ac6424b9 | 198 | wait_queue_entry_t wait; |
fee096de DH |
199 | bool requeue; |
200 | ||
201 | /* if the object we're waiting for is queued for processing, | |
202 | * then just put ourselves on the queue behind it */ | |
8b8edefa | 203 | if (work_pending(&xobject->fscache.work)) { |
fee096de DH |
204 | _debug("queue OBJ%x behind OBJ%x immediately", |
205 | object->fscache.debug_id, | |
206 | xobject->fscache.debug_id); | |
207 | goto requeue; | |
208 | } | |
209 | ||
210 | /* otherwise we sleep until either the object we're waiting for | |
8b8edefa | 211 | * is done, or the fscache_object is congested */ |
fee096de DH |
212 | wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE); |
213 | init_wait(&wait); | |
214 | requeue = false; | |
215 | do { | |
216 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
217 | if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) | |
218 | break; | |
8b8edefa TH |
219 | |
220 | requeue = fscache_object_sleep_till_congested(&timeout); | |
fee096de DH |
221 | } while (timeout > 0 && !requeue); |
222 | finish_wait(wq, &wait); | |
223 | ||
224 | if (requeue && | |
225 | test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { | |
226 | _debug("queue OBJ%x behind OBJ%x after wait", | |
227 | object->fscache.debug_id, | |
228 | xobject->fscache.debug_id); | |
229 | goto requeue; | |
230 | } | |
231 | ||
232 | if (timeout <= 0) { | |
4e1eb883 | 233 | pr_err("\n"); |
0227d6ab | 234 | pr_err("Error: Overlong wait for old active object to go away\n"); |
fee096de DH |
235 | cachefiles_printk_object(object, xobject); |
236 | goto requeue; | |
237 | } | |
238 | } | |
239 | ||
240 | ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)); | |
9ae326a6 | 241 | |
b7e768b7 NC |
242 | cache->cache.ops->put_object(&xobject->fscache, |
243 | (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_retry); | |
9ae326a6 | 244 | goto try_again; |
fee096de DH |
245 | |
246 | requeue: | |
b7e768b7 NC |
247 | cache->cache.ops->put_object(&xobject->fscache, |
248 | (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_timeo); | |
fee096de DH |
249 | _leave(" = -ETIMEDOUT"); |
250 | return -ETIMEDOUT; | |
9ae326a6 DH |
251 | } |
252 | ||
a5b3a80b DH |
253 | /* |
254 | * Mark an object as being inactive. | |
255 | */ | |
256 | void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, | |
a818101d DH |
257 | struct cachefiles_object *object, |
258 | blkcnt_t i_blocks) | |
a5b3a80b | 259 | { |
a18feb55 DH |
260 | struct dentry *dentry = object->dentry; |
261 | struct inode *inode = d_backing_inode(dentry); | |
262 | ||
263 | trace_cachefiles_mark_inactive(object, dentry, inode); | |
264 | ||
a5b3a80b DH |
265 | write_lock(&cache->active_lock); |
266 | rb_erase(&object->active_node, &cache->active_nodes); | |
267 | clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); | |
268 | write_unlock(&cache->active_lock); | |
269 | ||
270 | wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE); | |
271 | ||
272 | /* This object can now be culled, so we need to let the daemon know | |
273 | * that there is something it can remove if it needs to. | |
274 | */ | |
db20a892 | 275 | atomic_long_add(i_blocks, &cache->b_released); |
a5b3a80b DH |
276 | if (atomic_inc_return(&cache->f_released)) |
277 | cachefiles_state_changed(cache); | |
278 | } | |
279 | ||
9ae326a6 DH |
280 | /* |
281 | * delete an object representation from the cache | |
282 | * - file backed objects are unlinked | |
283 | * - directory backed objects are stuffed into the graveyard for userspace to | |
284 | * delete | |
285 | * - unlocks the directory mutex | |
286 | */ | |
287 | static int cachefiles_bury_object(struct cachefiles_cache *cache, | |
a18feb55 | 288 | struct cachefiles_object *object, |
9ae326a6 | 289 | struct dentry *dir, |
c61ea31d | 290 | struct dentry *rep, |
182d919b DH |
291 | bool preemptive, |
292 | enum fscache_why_object_killed why) | |
9ae326a6 DH |
293 | { |
294 | struct dentry *grave, *trap; | |
82140443 | 295 | struct path path, path_to_graveyard; |
9ae326a6 DH |
296 | char nbuffer[8 + 8 + 1]; |
297 | int ret; | |
298 | ||
a455589f | 299 | _enter(",'%pd','%pd'", dir, rep); |
9ae326a6 | 300 | |
c61ea31d DH |
301 | _debug("remove %p from %p", rep, dir); |
302 | ||
9ae326a6 | 303 | /* non-directories can just be unlinked */ |
e36cb0b8 | 304 | if (!d_is_dir(rep)) { |
9ae326a6 | 305 | _debug("unlink stale object"); |
9ae326a6 | 306 | |
82140443 DH |
307 | path.mnt = cache->mnt; |
308 | path.dentry = dir; | |
309 | ret = security_path_unlink(&path, rep); | |
310 | if (ret < 0) { | |
311 | cachefiles_io_error(cache, "Unlink security error"); | |
312 | } else { | |
a18feb55 | 313 | trace_cachefiles_unlink(object, rep, why); |
6521f891 CB |
314 | ret = vfs_unlink(&init_user_ns, d_inode(dir), rep, |
315 | 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", | |
34e06fe4 | 337 | (uint32_t) ktime_get_real_seconds(), |
9ae326a6 DH |
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 */ | |
169b8033 | 344 | if (rep->d_parent != dir || IS_DEADDIR(d_inode(rep))) { |
9ae326a6 DH |
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 { | |
9fe61450 | 416 | struct renamedata rd = { |
6521f891 | 417 | .old_mnt_userns = &init_user_ns, |
9fe61450 CB |
418 | .old_dir = d_inode(dir), |
419 | .old_dentry = rep, | |
6521f891 | 420 | .new_mnt_userns = &init_user_ns, |
9fe61450 CB |
421 | .new_dir = d_inode(cache->graveyard), |
422 | .new_dentry = grave, | |
423 | }; | |
a18feb55 | 424 | trace_cachefiles_rename(object, rep, grave, why); |
9fe61450 | 425 | ret = vfs_rename(&rd); |
82140443 DH |
426 | if (ret != 0 && ret != -ENOMEM) |
427 | cachefiles_io_error(cache, | |
428 | "Rename failed with error %d", ret); | |
9ae326a6 | 429 | |
82140443 | 430 | if (preemptive) |
182d919b | 431 | cachefiles_mark_object_buried(cache, rep, why); |
82140443 | 432 | } |
c61ea31d | 433 | |
9ae326a6 DH |
434 | unlock_rename(cache->graveyard, dir); |
435 | dput(grave); | |
436 | _leave(" = 0"); | |
437 | return 0; | |
438 | } | |
439 | ||
440 | /* | |
441 | * delete an object representation from the cache | |
442 | */ | |
443 | int cachefiles_delete_object(struct cachefiles_cache *cache, | |
444 | struct cachefiles_object *object) | |
445 | { | |
446 | struct dentry *dir; | |
447 | int ret; | |
448 | ||
c61ea31d | 449 | _enter(",OBJ%x{%p}", object->fscache.debug_id, object->dentry); |
9ae326a6 DH |
450 | |
451 | ASSERT(object->dentry); | |
466b77bc | 452 | ASSERT(d_backing_inode(object->dentry)); |
9ae326a6 DH |
453 | ASSERT(object->dentry->d_parent); |
454 | ||
455 | dir = dget_parent(object->dentry); | |
456 | ||
5955102c | 457 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
8f9941ae | 458 | |
182d919b | 459 | if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) { |
c61ea31d DH |
460 | /* object allocation for the same key preemptively deleted this |
461 | * object's file so that it could create its own file */ | |
462 | _debug("object preemptively buried"); | |
5955102c | 463 | inode_unlock(d_inode(dir)); |
8f9941ae | 464 | ret = 0; |
c61ea31d DH |
465 | } else { |
466 | /* we need to check that our parent is _still_ our parent - it | |
467 | * may have been renamed */ | |
468 | if (dir == object->dentry->d_parent) { | |
a18feb55 | 469 | ret = cachefiles_bury_object(cache, object, dir, |
182d919b DH |
470 | object->dentry, false, |
471 | FSCACHE_OBJECT_WAS_RETIRED); | |
c61ea31d DH |
472 | } else { |
473 | /* it got moved, presumably by cachefilesd culling it, | |
474 | * so it's no longer in the key path and we can ignore | |
475 | * it */ | |
5955102c | 476 | inode_unlock(d_inode(dir)); |
c61ea31d DH |
477 | ret = 0; |
478 | } | |
8f9941ae | 479 | } |
9ae326a6 DH |
480 | |
481 | dput(dir); | |
482 | _leave(" = %d", ret); | |
483 | return ret; | |
484 | } | |
485 | ||
486 | /* | |
487 | * walk from the parent object to the child object through the backing | |
488 | * filesystem, creating directories as we go | |
489 | */ | |
490 | int cachefiles_walk_to_object(struct cachefiles_object *parent, | |
491 | struct cachefiles_object *object, | |
492 | const char *key, | |
493 | struct cachefiles_xattr *auxdata) | |
494 | { | |
495 | struct cachefiles_cache *cache; | |
496 | struct dentry *dir, *next = NULL; | |
a18feb55 | 497 | struct inode *inode; |
82140443 | 498 | struct path path; |
9ae326a6 DH |
499 | unsigned long start; |
500 | const char *name; | |
501 | int ret, nlen; | |
502 | ||
c61ea31d DH |
503 | _enter("OBJ%x{%p},OBJ%x,%s,", |
504 | parent->fscache.debug_id, parent->dentry, | |
505 | object->fscache.debug_id, key); | |
9ae326a6 DH |
506 | |
507 | cache = container_of(parent->fscache.cache, | |
508 | struct cachefiles_cache, cache); | |
82140443 | 509 | path.mnt = cache->mnt; |
9ae326a6 DH |
510 | |
511 | ASSERT(parent->dentry); | |
466b77bc | 512 | ASSERT(d_backing_inode(parent->dentry)); |
9ae326a6 | 513 | |
e36cb0b8 | 514 | if (!(d_is_dir(parent->dentry))) { |
9ae326a6 DH |
515 | // TODO: convert file to dir |
516 | _leave("looking up in none directory"); | |
517 | return -ENOBUFS; | |
518 | } | |
519 | ||
520 | dir = dget(parent->dentry); | |
521 | ||
522 | advance: | |
523 | /* attempt to transit the first directory component */ | |
524 | name = key; | |
525 | nlen = strlen(key); | |
526 | ||
527 | /* key ends in a double NUL */ | |
528 | key = key + nlen + 1; | |
529 | if (!*key) | |
530 | key = NULL; | |
531 | ||
532 | lookup_again: | |
533 | /* search the current directory for the element name */ | |
534 | _debug("lookup '%s'", name); | |
535 | ||
5955102c | 536 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
9ae326a6 DH |
537 | |
538 | start = jiffies; | |
539 | next = lookup_one_len(name, dir, nlen); | |
540 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
a18feb55 DH |
541 | if (IS_ERR(next)) { |
542 | trace_cachefiles_lookup(object, next, NULL); | |
9ae326a6 | 543 | goto lookup_error; |
a18feb55 | 544 | } |
9ae326a6 | 545 | |
a18feb55 DH |
546 | inode = d_backing_inode(next); |
547 | trace_cachefiles_lookup(object, next, inode); | |
548 | _debug("next -> %p %s", next, inode ? "positive" : "negative"); | |
9ae326a6 DH |
549 | |
550 | if (!key) | |
a18feb55 | 551 | object->new = !inode; |
9ae326a6 DH |
552 | |
553 | /* if this element of the path doesn't exist, then the lookup phase | |
554 | * failed, and we can release any readers in the certain knowledge that | |
555 | * there's nothing for them to actually read */ | |
466b77bc | 556 | if (d_is_negative(next)) |
9ae326a6 DH |
557 | fscache_object_lookup_negative(&object->fscache); |
558 | ||
559 | /* we need to create the object if it's negative */ | |
560 | if (key || object->type == FSCACHE_COOKIE_TYPE_INDEX) { | |
561 | /* index objects and intervening tree levels must be subdirs */ | |
466b77bc | 562 | if (d_is_negative(next)) { |
9ae326a6 DH |
563 | ret = cachefiles_has_space(cache, 1, 0); |
564 | if (ret < 0) | |
182d919b | 565 | goto no_space_error; |
9ae326a6 | 566 | |
82140443 DH |
567 | path.dentry = dir; |
568 | ret = security_path_mkdir(&path, next, 0); | |
569 | if (ret < 0) | |
570 | goto create_error; | |
9ae326a6 | 571 | start = jiffies; |
6521f891 | 572 | ret = vfs_mkdir(&init_user_ns, d_inode(dir), next, 0); |
9ae326a6 | 573 | cachefiles_hist(cachefiles_mkdir_histogram, start); |
a18feb55 DH |
574 | if (!key) |
575 | trace_cachefiles_mkdir(object, next, ret); | |
9ae326a6 DH |
576 | if (ret < 0) |
577 | goto create_error; | |
578 | ||
9c3e9025 AV |
579 | if (unlikely(d_unhashed(next))) { |
580 | dput(next); | |
581 | inode_unlock(d_inode(dir)); | |
582 | goto lookup_again; | |
583 | } | |
466b77bc | 584 | ASSERT(d_backing_inode(next)); |
9ae326a6 DH |
585 | |
586 | _debug("mkdir -> %p{%p{ino=%lu}}", | |
466b77bc | 587 | next, d_backing_inode(next), d_backing_inode(next)->i_ino); |
9ae326a6 | 588 | |
ce40fa78 | 589 | } else if (!d_can_lookup(next)) { |
6ff66ac7 | 590 | pr_err("inode %lu is not a directory\n", |
466b77bc | 591 | d_backing_inode(next)->i_ino); |
9ae326a6 DH |
592 | ret = -ENOBUFS; |
593 | goto error; | |
594 | } | |
595 | ||
596 | } else { | |
597 | /* non-index objects start out life as files */ | |
466b77bc | 598 | if (d_is_negative(next)) { |
9ae326a6 DH |
599 | ret = cachefiles_has_space(cache, 1, 0); |
600 | if (ret < 0) | |
182d919b | 601 | goto no_space_error; |
9ae326a6 | 602 | |
82140443 DH |
603 | path.dentry = dir; |
604 | ret = security_path_mknod(&path, next, S_IFREG, 0); | |
605 | if (ret < 0) | |
606 | goto create_error; | |
9ae326a6 | 607 | start = jiffies; |
6521f891 CB |
608 | ret = vfs_create(&init_user_ns, d_inode(dir), next, |
609 | S_IFREG, true); | |
9ae326a6 | 610 | cachefiles_hist(cachefiles_create_histogram, start); |
a18feb55 | 611 | trace_cachefiles_create(object, next, ret); |
9ae326a6 DH |
612 | if (ret < 0) |
613 | goto create_error; | |
614 | ||
466b77bc | 615 | ASSERT(d_backing_inode(next)); |
9ae326a6 DH |
616 | |
617 | _debug("create -> %p{%p{ino=%lu}}", | |
466b77bc | 618 | next, d_backing_inode(next), d_backing_inode(next)->i_ino); |
9ae326a6 | 619 | |
ce40fa78 | 620 | } else if (!d_can_lookup(next) && |
e36cb0b8 | 621 | !d_is_reg(next) |
9ae326a6 | 622 | ) { |
6ff66ac7 | 623 | pr_err("inode %lu is not a file or directory\n", |
466b77bc | 624 | d_backing_inode(next)->i_ino); |
9ae326a6 DH |
625 | ret = -ENOBUFS; |
626 | goto error; | |
627 | } | |
628 | } | |
629 | ||
630 | /* process the next component */ | |
631 | if (key) { | |
632 | _debug("advance"); | |
5955102c | 633 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
634 | dput(dir); |
635 | dir = next; | |
636 | next = NULL; | |
637 | goto advance; | |
638 | } | |
639 | ||
640 | /* we've found the object we were looking for */ | |
641 | object->dentry = next; | |
642 | ||
643 | /* if we've found that the terminal object exists, then we need to | |
644 | * check its attributes and delete it if it's out of date */ | |
645 | if (!object->new) { | |
a455589f | 646 | _debug("validate '%pd'", next); |
9ae326a6 DH |
647 | |
648 | ret = cachefiles_check_object_xattr(object, auxdata); | |
649 | if (ret == -ESTALE) { | |
650 | /* delete the object (the deleter drops the directory | |
651 | * mutex) */ | |
652 | object->dentry = NULL; | |
653 | ||
a18feb55 DH |
654 | ret = cachefiles_bury_object(cache, object, dir, next, |
655 | true, | |
182d919b | 656 | FSCACHE_OBJECT_IS_STALE); |
9ae326a6 DH |
657 | dput(next); |
658 | next = NULL; | |
659 | ||
660 | if (ret < 0) | |
661 | goto delete_error; | |
662 | ||
663 | _debug("redo lookup"); | |
182d919b | 664 | fscache_object_retrying_stale(&object->fscache); |
9ae326a6 DH |
665 | goto lookup_again; |
666 | } | |
667 | } | |
668 | ||
669 | /* note that we're now using this object */ | |
fee096de | 670 | ret = cachefiles_mark_object_active(cache, object); |
9ae326a6 | 671 | |
5955102c | 672 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
673 | dput(dir); |
674 | dir = NULL; | |
675 | ||
fee096de DH |
676 | if (ret == -ETIMEDOUT) |
677 | goto mark_active_timed_out; | |
678 | ||
9ae326a6 DH |
679 | _debug("=== OBTAINED_OBJECT ==="); |
680 | ||
681 | if (object->new) { | |
682 | /* attach data to a newly constructed terminal object */ | |
683 | ret = cachefiles_set_object_xattr(object, auxdata); | |
684 | if (ret < 0) | |
685 | goto check_error; | |
686 | } else { | |
687 | /* always update the atime on an object we've just looked up | |
688 | * (this is used to keep track of culling, and atimes are only | |
689 | * updated by read, write and readdir but not lookup or | |
690 | * open) */ | |
68ac1234 AV |
691 | path.dentry = next; |
692 | touch_atime(&path); | |
9ae326a6 DH |
693 | } |
694 | ||
695 | /* open a file interface onto a data file */ | |
696 | if (object->type != FSCACHE_COOKIE_TYPE_INDEX) { | |
e36cb0b8 | 697 | if (d_is_reg(object->dentry)) { |
9ae326a6 DH |
698 | const struct address_space_operations *aops; |
699 | ||
700 | ret = -EPERM; | |
466b77bc | 701 | aops = d_backing_inode(object->dentry)->i_mapping->a_ops; |
9ae326a6 DH |
702 | if (!aops->bmap) |
703 | goto check_error; | |
95201a40 N |
704 | if (object->dentry->d_sb->s_blocksize > PAGE_SIZE) |
705 | goto check_error; | |
9ae326a6 DH |
706 | |
707 | object->backer = object->dentry; | |
708 | } else { | |
709 | BUG(); // TODO: open file in data-class subdir | |
710 | } | |
711 | } | |
712 | ||
713 | object->new = 0; | |
714 | fscache_obtained_object(&object->fscache); | |
715 | ||
466b77bc | 716 | _leave(" = 0 [%lu]", d_backing_inode(object->dentry)->i_ino); |
9ae326a6 DH |
717 | return 0; |
718 | ||
182d919b DH |
719 | no_space_error: |
720 | fscache_object_mark_killed(&object->fscache, FSCACHE_OBJECT_NO_SPACE); | |
9ae326a6 DH |
721 | create_error: |
722 | _debug("create error %d", ret); | |
723 | if (ret == -EIO) | |
724 | cachefiles_io_error(cache, "Create/mkdir failed"); | |
725 | goto error; | |
726 | ||
fee096de DH |
727 | mark_active_timed_out: |
728 | _debug("mark active timed out"); | |
729 | goto release_dentry; | |
730 | ||
9ae326a6 DH |
731 | check_error: |
732 | _debug("check error %d", ret); | |
a818101d DH |
733 | cachefiles_mark_object_inactive( |
734 | cache, object, d_backing_inode(object->dentry)->i_blocks); | |
fee096de | 735 | release_dentry: |
9ae326a6 DH |
736 | dput(object->dentry); |
737 | object->dentry = NULL; | |
738 | goto error_out; | |
739 | ||
740 | delete_error: | |
741 | _debug("delete error %d", ret); | |
742 | goto error_out2; | |
743 | ||
744 | lookup_error: | |
745 | _debug("lookup error %ld", PTR_ERR(next)); | |
746 | ret = PTR_ERR(next); | |
747 | if (ret == -EIO) | |
748 | cachefiles_io_error(cache, "Lookup failed"); | |
749 | next = NULL; | |
750 | error: | |
5955102c | 751 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
752 | dput(next); |
753 | error_out2: | |
754 | dput(dir); | |
755 | error_out: | |
9ae326a6 DH |
756 | _leave(" = error %d", -ret); |
757 | return ret; | |
758 | } | |
759 | ||
760 | /* | |
761 | * get a subdirectory | |
762 | */ | |
763 | struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, | |
764 | struct dentry *dir, | |
765 | const char *dirname) | |
766 | { | |
767 | struct dentry *subdir; | |
768 | unsigned long start; | |
82140443 | 769 | struct path path; |
9ae326a6 DH |
770 | int ret; |
771 | ||
772 | _enter(",,%s", dirname); | |
773 | ||
774 | /* search the current directory for the element name */ | |
5955102c | 775 | inode_lock(d_inode(dir)); |
9ae326a6 | 776 | |
9c3e9025 | 777 | retry: |
9ae326a6 DH |
778 | start = jiffies; |
779 | subdir = lookup_one_len(dirname, dir, strlen(dirname)); | |
780 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
781 | if (IS_ERR(subdir)) { | |
782 | if (PTR_ERR(subdir) == -ENOMEM) | |
783 | goto nomem_d_alloc; | |
784 | goto lookup_error; | |
785 | } | |
786 | ||
787 | _debug("subdir -> %p %s", | |
466b77bc | 788 | subdir, d_backing_inode(subdir) ? "positive" : "negative"); |
9ae326a6 DH |
789 | |
790 | /* we need to create the subdir if it doesn't exist yet */ | |
466b77bc | 791 | if (d_is_negative(subdir)) { |
9ae326a6 DH |
792 | ret = cachefiles_has_space(cache, 1, 0); |
793 | if (ret < 0) | |
794 | goto mkdir_error; | |
795 | ||
796 | _debug("attempt mkdir"); | |
797 | ||
82140443 DH |
798 | path.mnt = cache->mnt; |
799 | path.dentry = dir; | |
800 | ret = security_path_mkdir(&path, subdir, 0700); | |
801 | if (ret < 0) | |
802 | goto mkdir_error; | |
6521f891 | 803 | ret = vfs_mkdir(&init_user_ns, d_inode(dir), subdir, 0700); |
9ae326a6 DH |
804 | if (ret < 0) |
805 | goto mkdir_error; | |
806 | ||
9c3e9025 AV |
807 | if (unlikely(d_unhashed(subdir))) { |
808 | dput(subdir); | |
809 | goto retry; | |
810 | } | |
466b77bc | 811 | ASSERT(d_backing_inode(subdir)); |
9ae326a6 DH |
812 | |
813 | _debug("mkdir -> %p{%p{ino=%lu}}", | |
814 | subdir, | |
466b77bc DH |
815 | d_backing_inode(subdir), |
816 | d_backing_inode(subdir)->i_ino); | |
9ae326a6 DH |
817 | } |
818 | ||
5955102c | 819 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
820 | |
821 | /* we need to make sure the subdir is a directory */ | |
466b77bc | 822 | ASSERT(d_backing_inode(subdir)); |
9ae326a6 | 823 | |
ce40fa78 | 824 | if (!d_can_lookup(subdir)) { |
6ff66ac7 | 825 | pr_err("%s is not a directory\n", dirname); |
9ae326a6 DH |
826 | ret = -EIO; |
827 | goto check_error; | |
828 | } | |
829 | ||
830 | ret = -EPERM; | |
5d6c3191 | 831 | if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) || |
466b77bc DH |
832 | !d_backing_inode(subdir)->i_op->lookup || |
833 | !d_backing_inode(subdir)->i_op->mkdir || | |
834 | !d_backing_inode(subdir)->i_op->create || | |
2773bf00 | 835 | !d_backing_inode(subdir)->i_op->rename || |
466b77bc DH |
836 | !d_backing_inode(subdir)->i_op->rmdir || |
837 | !d_backing_inode(subdir)->i_op->unlink) | |
9ae326a6 DH |
838 | goto check_error; |
839 | ||
466b77bc | 840 | _leave(" = [%lu]", d_backing_inode(subdir)->i_ino); |
9ae326a6 DH |
841 | return subdir; |
842 | ||
843 | check_error: | |
844 | dput(subdir); | |
845 | _leave(" = %d [check]", ret); | |
846 | return ERR_PTR(ret); | |
847 | ||
848 | mkdir_error: | |
5955102c | 849 | inode_unlock(d_inode(dir)); |
9ae326a6 | 850 | dput(subdir); |
6ff66ac7 | 851 | pr_err("mkdir %s failed with error %d\n", dirname, ret); |
9ae326a6 DH |
852 | return ERR_PTR(ret); |
853 | ||
854 | lookup_error: | |
5955102c | 855 | inode_unlock(d_inode(dir)); |
9ae326a6 | 856 | ret = PTR_ERR(subdir); |
6ff66ac7 | 857 | pr_err("Lookup %s failed with error %d\n", dirname, ret); |
9ae326a6 DH |
858 | return ERR_PTR(ret); |
859 | ||
860 | nomem_d_alloc: | |
5955102c | 861 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
862 | _leave(" = -ENOMEM"); |
863 | return ERR_PTR(-ENOMEM); | |
864 | } | |
865 | ||
866 | /* | |
867 | * find out if an object is in use or not | |
868 | * - if finds object and it's not in use: | |
869 | * - returns a pointer to the object and a reference on it | |
870 | * - returns with the directory locked | |
871 | */ | |
872 | static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache, | |
873 | struct dentry *dir, | |
874 | char *filename) | |
875 | { | |
876 | struct cachefiles_object *object; | |
877 | struct rb_node *_n; | |
878 | struct dentry *victim; | |
879 | unsigned long start; | |
880 | int ret; | |
881 | ||
a455589f AV |
882 | //_enter(",%pd/,%s", |
883 | // dir, filename); | |
9ae326a6 DH |
884 | |
885 | /* look up the victim */ | |
5955102c | 886 | inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); |
9ae326a6 DH |
887 | |
888 | start = jiffies; | |
889 | victim = lookup_one_len(filename, dir, strlen(filename)); | |
890 | cachefiles_hist(cachefiles_lookup_histogram, start); | |
891 | if (IS_ERR(victim)) | |
892 | goto lookup_error; | |
893 | ||
894 | //_debug("victim -> %p %s", | |
466b77bc | 895 | // victim, d_backing_inode(victim) ? "positive" : "negative"); |
9ae326a6 DH |
896 | |
897 | /* if the object is no longer there then we probably retired the object | |
898 | * at the netfs's request whilst the cull was in progress | |
899 | */ | |
466b77bc | 900 | if (d_is_negative(victim)) { |
5955102c | 901 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
902 | dput(victim); |
903 | _leave(" = -ENOENT [absent]"); | |
904 | return ERR_PTR(-ENOENT); | |
905 | } | |
906 | ||
907 | /* check to see if we're using this object */ | |
908 | read_lock(&cache->active_lock); | |
909 | ||
910 | _n = cache->active_nodes.rb_node; | |
911 | ||
912 | while (_n) { | |
913 | object = rb_entry(_n, struct cachefiles_object, active_node); | |
914 | ||
915 | if (object->dentry > victim) | |
916 | _n = _n->rb_left; | |
917 | else if (object->dentry < victim) | |
918 | _n = _n->rb_right; | |
919 | else | |
920 | goto object_in_use; | |
921 | } | |
922 | ||
923 | read_unlock(&cache->active_lock); | |
924 | ||
925 | //_leave(" = %p", victim); | |
926 | return victim; | |
927 | ||
928 | object_in_use: | |
929 | read_unlock(&cache->active_lock); | |
5955102c | 930 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
931 | dput(victim); |
932 | //_leave(" = -EBUSY [in use]"); | |
933 | return ERR_PTR(-EBUSY); | |
934 | ||
935 | lookup_error: | |
5955102c | 936 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
937 | ret = PTR_ERR(victim); |
938 | if (ret == -ENOENT) { | |
939 | /* file or dir now absent - probably retired by netfs */ | |
940 | _leave(" = -ESTALE [absent]"); | |
941 | return ERR_PTR(-ESTALE); | |
942 | } | |
943 | ||
944 | if (ret == -EIO) { | |
945 | cachefiles_io_error(cache, "Lookup failed"); | |
946 | } else if (ret != -ENOMEM) { | |
6ff66ac7 | 947 | pr_err("Internal error: %d\n", ret); |
9ae326a6 DH |
948 | ret = -EIO; |
949 | } | |
950 | ||
951 | _leave(" = %d", ret); | |
952 | return ERR_PTR(ret); | |
953 | } | |
954 | ||
955 | /* | |
956 | * cull an object if it's not in use | |
957 | * - called only by cache manager daemon | |
958 | */ | |
959 | int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, | |
960 | char *filename) | |
961 | { | |
962 | struct dentry *victim; | |
963 | int ret; | |
964 | ||
a455589f | 965 | _enter(",%pd/,%s", dir, filename); |
9ae326a6 DH |
966 | |
967 | victim = cachefiles_check_active(cache, dir, filename); | |
968 | if (IS_ERR(victim)) | |
969 | return PTR_ERR(victim); | |
970 | ||
971 | _debug("victim -> %p %s", | |
466b77bc | 972 | victim, d_backing_inode(victim) ? "positive" : "negative"); |
9ae326a6 DH |
973 | |
974 | /* okay... the victim is not being used so we can cull it | |
975 | * - start by marking it as stale | |
976 | */ | |
977 | _debug("victim is cullable"); | |
978 | ||
979 | ret = cachefiles_remove_object_xattr(cache, victim); | |
980 | if (ret < 0) | |
981 | goto error_unlock; | |
982 | ||
983 | /* actually remove the victim (drops the dir mutex) */ | |
984 | _debug("bury"); | |
985 | ||
a18feb55 | 986 | ret = cachefiles_bury_object(cache, NULL, dir, victim, false, |
182d919b | 987 | FSCACHE_OBJECT_WAS_CULLED); |
9ae326a6 DH |
988 | if (ret < 0) |
989 | goto error; | |
990 | ||
991 | dput(victim); | |
992 | _leave(" = 0"); | |
993 | return 0; | |
994 | ||
995 | error_unlock: | |
5955102c | 996 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
997 | error: |
998 | dput(victim); | |
999 | if (ret == -ENOENT) { | |
1000 | /* file or dir now absent - probably retired by netfs */ | |
1001 | _leave(" = -ESTALE [absent]"); | |
1002 | return -ESTALE; | |
1003 | } | |
1004 | ||
1005 | if (ret != -ENOMEM) { | |
6ff66ac7 | 1006 | pr_err("Internal error: %d\n", ret); |
9ae326a6 DH |
1007 | ret = -EIO; |
1008 | } | |
1009 | ||
1010 | _leave(" = %d", ret); | |
1011 | return ret; | |
1012 | } | |
1013 | ||
1014 | /* | |
1015 | * find out if an object is in use or not | |
1016 | * - called only by cache manager daemon | |
1017 | * - returns -EBUSY or 0 to indicate whether an object is in use or not | |
1018 | */ | |
1019 | int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir, | |
1020 | char *filename) | |
1021 | { | |
1022 | struct dentry *victim; | |
1023 | ||
a455589f AV |
1024 | //_enter(",%pd/,%s", |
1025 | // dir, filename); | |
9ae326a6 DH |
1026 | |
1027 | victim = cachefiles_check_active(cache, dir, filename); | |
1028 | if (IS_ERR(victim)) | |
1029 | return PTR_ERR(victim); | |
1030 | ||
5955102c | 1031 | inode_unlock(d_inode(dir)); |
9ae326a6 DH |
1032 | dput(victim); |
1033 | //_leave(" = 0"); | |
1034 | return 0; | |
1035 | } |