blob: 4ae75006e73bd20e04562240e1e85e63b63f74a4 [file] [log] [blame]
David Howells9ae326a2009-04-03 16:42:41 +01001/* 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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090022#include <linux/slab.h>
David Howells9ae326a2009-04-03 16:42:41 +010023#include "internal.h"
24
David Howellsd0e27b72009-11-19 18:12:02 +000025#define CACHEFILES_KEYBUF_SIZE 512
26
27/*
28 * dump debugging info about an object
29 */
30static noinline
31void __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
Fabian Frederick4e1eb882014-06-06 14:37:32 -070038 pr_err("%sobject: OBJ%x\n", prefix, object->fscache.debug_id);
39 pr_err("%sobjstate=%s fl=%lx wbusy=%x ev=%lx[%lx]\n",
David Howellscaaef692013-05-10 19:50:26 +010040 prefix, object->fscache.state->name,
Tejun Heo8b8edef2010-07-20 22:09:01 +020041 object->fscache.flags, work_busy(&object->fscache.work),
David Howellsc2d35bf2012-12-05 13:34:47 +000042 object->fscache.events, object->fscache.event_mask);
Fabian Frederick4e1eb882014-06-06 14:37:32 -070043 pr_err("%sops=%u inp=%u exc=%u\n",
David Howellsd0e27b72009-11-19 18:12:02 +000044 prefix, object->fscache.n_ops, object->fscache.n_in_progress,
45 object->fscache.n_exclusive);
Fabian Frederick4e1eb882014-06-06 14:37:32 -070046 pr_err("%sparent=%p\n",
David Howellsd0e27b72009-11-19 18:12:02 +000047 prefix, object->fscache.parent);
48
49 spin_lock(&object->fscache.lock);
50 cookie = object->fscache.cookie;
51 if (cookie) {
Fabian Frederick4e1eb882014-06-06 14:37:32 -070052 pr_err("%scookie=%p [pr=%p nd=%p fl=%lx]\n",
David Howellsd0e27b72009-11-19 18:12:02 +000053 prefix,
54 object->fscache.cookie,
55 object->fscache.cookie->parent,
56 object->fscache.cookie->netfs_data,
57 object->fscache.cookie->flags);
David Howells509bf242013-09-20 14:18:00 +010058 if (keybuf && cookie->def)
David Howellsd0e27b72009-11-19 18:12:02 +000059 keylen = cookie->def->get_key(cookie->netfs_data, keybuf,
60 CACHEFILES_KEYBUF_SIZE);
61 else
62 keylen = 0;
63 } else {
Fabian Frederick4e1eb882014-06-06 14:37:32 -070064 pr_err("%scookie=NULL\n", prefix);
David Howellsd0e27b72009-11-19 18:12:02 +000065 keylen = 0;
66 }
67 spin_unlock(&object->fscache.lock);
68
69 if (keylen) {
Fabian Frederick4e1eb882014-06-06 14:37:32 -070070 pr_err("%skey=[%u] '", prefix, keylen);
David Howellsd0e27b72009-11-19 18:12:02 +000071 for (loop = 0; loop < keylen; loop++)
Fabian Frederick4e1eb882014-06-06 14:37:32 -070072 pr_cont("%02x", keybuf[loop]);
73 pr_cont("'\n");
David Howellsd0e27b72009-11-19 18:12:02 +000074 }
75}
76
77/*
78 * dump debugging info about a pair of objects
79 */
80static 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
David Howells9ae326a2009-04-03 16:42:41 +010093/*
David Howellsc61ea312010-05-11 16:51:39 +010094 * 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 */
99static void cachefiles_mark_object_buried(struct cachefiles_cache *cache,
David Howells182d9192015-02-19 23:47:31 +0000100 struct dentry *dentry,
101 enum fscache_why_object_killed why)
David Howellsc61ea312010-05-11 16:51:39 +0100102{
103 struct cachefiles_object *object;
104 struct rb_node *p;
105
Al Viroa4555892014-10-21 20:11:25 -0400106 _enter(",'%pd'", dentry);
David Howellsc61ea312010-05-11 16:51:39 +0100107
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 */
126found_dentry:
127 kdebug("preemptive burial: OBJ%x [%s] %p",
128 object->fscache.debug_id,
David Howellscaaef692013-05-10 19:50:26 +0100129 object->fscache.state->name,
David Howellsc61ea312010-05-11 16:51:39 +0100130 dentry);
131
David Howells493f7bc2013-05-10 19:50:26 +0100132 if (fscache_object_is_live(&object->fscache)) {
Fabian Frederick4e1eb882014-06-06 14:37:32 -0700133 pr_err("\n");
Fabian Frederick0227d6ab2014-06-06 14:37:33 -0700134 pr_err("Error: Can't preemptively bury live object\n");
David Howellsc61ea312010-05-11 16:51:39 +0100135 cachefiles_printk_object(object, NULL);
David Howells182d9192015-02-19 23:47:31 +0000136 } else {
137 if (why != FSCACHE_OBJECT_IS_STALE)
138 fscache_object_mark_killed(&object->fscache, why);
David Howellsc61ea312010-05-11 16:51:39 +0100139 }
140
141 write_unlock(&cache->active_lock);
142 _leave(" [owner marked]");
143}
144
145/*
David Howells9ae326a2009-04-03 16:42:41 +0100146 * record the fact that an object is now active
147 */
David Howellsfee096d2009-11-19 18:12:05 +0000148static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
149 struct cachefiles_object *object)
David Howells9ae326a2009-04-03 16:42:41 +0100150{
151 struct cachefiles_object *xobject;
152 struct rb_node **_p, *_parent = NULL;
153 struct dentry *dentry;
154
155 _enter(",%p", object);
156
157try_again:
158 write_lock(&cache->active_lock);
159
David Howellsd0e27b72009-11-19 18:12:02 +0000160 if (test_and_set_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) {
Fabian Frederick0227d6ab2014-06-06 14:37:33 -0700161 pr_err("Error: Object already active\n");
David Howellsd0e27b72009-11-19 18:12:02 +0000162 cachefiles_printk_object(object, NULL);
David Howells9ae326a2009-04-03 16:42:41 +0100163 BUG();
David Howellsd0e27b72009-11-19 18:12:02 +0000164 }
David Howells9ae326a2009-04-03 16:42:41 +0100165
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);
David Howellsfee096d2009-11-19 18:12:05 +0000187 _leave(" = 0");
188 return 0;
David Howells9ae326a2009-04-03 16:42:41 +0100189
190 /* an old object from a previous incarnation is hogging the slot - we
191 * need to wait for it to be destroyed */
192wait_for_old_object:
David Howellsa30efe22014-09-30 14:50:30 +0100193 if (fscache_object_is_live(&xobject->fscache)) {
Fabian Frederick4e1eb882014-06-06 14:37:32 -0700194 pr_err("\n");
Fabian Frederick0227d6ab2014-06-06 14:37:33 -0700195 pr_err("Error: Unexpected object collision\n");
David Howellsd0e27b72009-11-19 18:12:02 +0000196 cachefiles_printk_object(object, xobject);
David Howells9ae326a2009-04-03 16:42:41 +0100197 BUG();
198 }
199 atomic_inc(&xobject->usage);
200 write_unlock(&cache->active_lock);
201
David Howellsfee096d2009-11-19 18:12:05 +0000202 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 */
Tejun Heo8b8edef2010-07-20 22:09:01 +0200211 if (work_pending(&xobject->fscache.work)) {
David Howellsfee096d2009-11-19 18:12:05 +0000212 _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
Tejun Heo8b8edef2010-07-20 22:09:01 +0200219 * is done, or the fscache_object is congested */
David Howellsfee096d2009-11-19 18:12:05 +0000220 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;
Tejun Heo8b8edef2010-07-20 22:09:01 +0200227
228 requeue = fscache_object_sleep_till_congested(&timeout);
David Howellsfee096d2009-11-19 18:12:05 +0000229 } 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) {
Fabian Frederick4e1eb882014-06-06 14:37:32 -0700241 pr_err("\n");
Fabian Frederick0227d6ab2014-06-06 14:37:33 -0700242 pr_err("Error: Overlong wait for old active object to go away\n");
David Howellsfee096d2009-11-19 18:12:05 +0000243 cachefiles_printk_object(object, xobject);
244 goto requeue;
245 }
246 }
247
248 ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags));
David Howells9ae326a2009-04-03 16:42:41 +0100249
250 cache->cache.ops->put_object(&xobject->fscache);
251 goto try_again;
David Howellsfee096d2009-11-19 18:12:05 +0000252
253requeue:
254 clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
255 cache->cache.ops->put_object(&xobject->fscache);
256 _leave(" = -ETIMEDOUT");
257 return -ETIMEDOUT;
David Howells9ae326a2009-04-03 16:42:41 +0100258}
259
260/*
David Howellsa5b3a802016-02-01 16:43:04 +0000261 * Mark an object as being inactive.
262 */
263void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
264 struct cachefiles_object *object)
265{
266 write_lock(&cache->active_lock);
267 rb_erase(&object->active_node, &cache->active_nodes);
268 clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
269 write_unlock(&cache->active_lock);
270
271 wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE);
272
273 /* This object can now be culled, so we need to let the daemon know
274 * that there is something it can remove if it needs to.
275 */
276 atomic_long_add(d_backing_inode(object->dentry)->i_blocks,
277 &cache->b_released);
278 if (atomic_inc_return(&cache->f_released))
279 cachefiles_state_changed(cache);
280}
281
282/*
David Howells9ae326a2009-04-03 16:42:41 +0100283 * delete an object representation from the cache
284 * - file backed objects are unlinked
285 * - directory backed objects are stuffed into the graveyard for userspace to
286 * delete
287 * - unlocks the directory mutex
288 */
289static int cachefiles_bury_object(struct cachefiles_cache *cache,
290 struct dentry *dir,
David Howellsc61ea312010-05-11 16:51:39 +0100291 struct dentry *rep,
David Howells182d9192015-02-19 23:47:31 +0000292 bool preemptive,
293 enum fscache_why_object_killed why)
David Howells9ae326a2009-04-03 16:42:41 +0100294{
295 struct dentry *grave, *trap;
David Howells82140442010-12-24 14:48:35 +0000296 struct path path, path_to_graveyard;
David Howells9ae326a2009-04-03 16:42:41 +0100297 char nbuffer[8 + 8 + 1];
298 int ret;
299
Al Viroa4555892014-10-21 20:11:25 -0400300 _enter(",'%pd','%pd'", dir, rep);
David Howells9ae326a2009-04-03 16:42:41 +0100301
David Howellsc61ea312010-05-11 16:51:39 +0100302 _debug("remove %p from %p", rep, dir);
303
David Howells9ae326a2009-04-03 16:42:41 +0100304 /* non-directories can just be unlinked */
David Howellse36cb0b2015-01-29 12:02:35 +0000305 if (!d_is_dir(rep)) {
David Howells9ae326a2009-04-03 16:42:41 +0100306 _debug("unlink stale object");
David Howells9ae326a2009-04-03 16:42:41 +0100307
David Howells82140442010-12-24 14:48:35 +0000308 path.mnt = cache->mnt;
309 path.dentry = dir;
310 ret = security_path_unlink(&path, rep);
311 if (ret < 0) {
312 cachefiles_io_error(cache, "Unlink security error");
313 } else {
David Howells5153bc82015-03-06 14:08:58 +0000314 ret = vfs_unlink(d_inode(dir), rep, NULL);
David Howells82140442010-12-24 14:48:35 +0000315
316 if (preemptive)
David Howells182d9192015-02-19 23:47:31 +0000317 cachefiles_mark_object_buried(cache, rep, why);
David Howells82140442010-12-24 14:48:35 +0000318 }
David Howellsc61ea312010-05-11 16:51:39 +0100319
Al Viro59551022016-01-22 15:40:57 -0500320 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100321
322 if (ret == -EIO)
323 cachefiles_io_error(cache, "Unlink failed");
324
325 _leave(" = %d", ret);
326 return ret;
327 }
328
329 /* directories have to be moved to the graveyard */
330 _debug("move stale object to graveyard");
Al Viro59551022016-01-22 15:40:57 -0500331 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100332
333try_again:
334 /* first step is to make up a grave dentry in the graveyard */
335 sprintf(nbuffer, "%08x%08x",
336 (uint32_t) get_seconds(),
337 (uint32_t) atomic_inc_return(&cache->gravecounter));
338
339 /* do the multiway lock magic */
340 trap = lock_rename(cache->graveyard, dir);
341
342 /* do some checks before getting the grave dentry */
343 if (rep->d_parent != dir) {
344 /* the entry was probably culled when we dropped the parent dir
345 * lock */
346 unlock_rename(cache->graveyard, dir);
347 _leave(" = 0 [culled?]");
348 return 0;
349 }
350
David Howellsce40fa72015-01-29 12:02:36 +0000351 if (!d_can_lookup(cache->graveyard)) {
David Howells9ae326a2009-04-03 16:42:41 +0100352 unlock_rename(cache->graveyard, dir);
353 cachefiles_io_error(cache, "Graveyard no longer a directory");
354 return -EIO;
355 }
356
357 if (trap == rep) {
358 unlock_rename(cache->graveyard, dir);
359 cachefiles_io_error(cache, "May not make directory loop");
360 return -EIO;
361 }
362
363 if (d_mountpoint(rep)) {
364 unlock_rename(cache->graveyard, dir);
365 cachefiles_io_error(cache, "Mountpoint in cache");
366 return -EIO;
367 }
368
369 grave = lookup_one_len(nbuffer, cache->graveyard, strlen(nbuffer));
370 if (IS_ERR(grave)) {
371 unlock_rename(cache->graveyard, dir);
372
373 if (PTR_ERR(grave) == -ENOMEM) {
374 _leave(" = -ENOMEM");
375 return -ENOMEM;
376 }
377
378 cachefiles_io_error(cache, "Lookup error %ld",
379 PTR_ERR(grave));
380 return -EIO;
381 }
382
David Howells466b77b2015-03-17 22:26:21 +0000383 if (d_is_positive(grave)) {
David Howells9ae326a2009-04-03 16:42:41 +0100384 unlock_rename(cache->graveyard, dir);
385 dput(grave);
386 grave = NULL;
387 cond_resched();
388 goto try_again;
389 }
390
391 if (d_mountpoint(grave)) {
392 unlock_rename(cache->graveyard, dir);
393 dput(grave);
394 cachefiles_io_error(cache, "Mountpoint in graveyard");
395 return -EIO;
396 }
397
398 /* target should not be an ancestor of source */
399 if (trap == grave) {
400 unlock_rename(cache->graveyard, dir);
401 dput(grave);
402 cachefiles_io_error(cache, "May not make directory loop");
403 return -EIO;
404 }
405
406 /* attempt the rename */
David Howells82140442010-12-24 14:48:35 +0000407 path.mnt = cache->mnt;
408 path.dentry = dir;
409 path_to_graveyard.mnt = cache->mnt;
410 path_to_graveyard.dentry = cache->graveyard;
Miklos Szeredi0b3974e2014-04-01 17:08:43 +0200411 ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0);
David Howells82140442010-12-24 14:48:35 +0000412 if (ret < 0) {
413 cachefiles_io_error(cache, "Rename security error %d", ret);
414 } else {
David Howells5153bc82015-03-06 14:08:58 +0000415 ret = vfs_rename(d_inode(dir), rep,
416 d_inode(cache->graveyard), grave, NULL, 0);
David Howells82140442010-12-24 14:48:35 +0000417 if (ret != 0 && ret != -ENOMEM)
418 cachefiles_io_error(cache,
419 "Rename failed with error %d", ret);
David Howells9ae326a2009-04-03 16:42:41 +0100420
David Howells82140442010-12-24 14:48:35 +0000421 if (preemptive)
David Howells182d9192015-02-19 23:47:31 +0000422 cachefiles_mark_object_buried(cache, rep, why);
David Howells82140442010-12-24 14:48:35 +0000423 }
David Howellsc61ea312010-05-11 16:51:39 +0100424
David Howells9ae326a2009-04-03 16:42:41 +0100425 unlock_rename(cache->graveyard, dir);
426 dput(grave);
427 _leave(" = 0");
428 return 0;
429}
430
431/*
432 * delete an object representation from the cache
433 */
434int cachefiles_delete_object(struct cachefiles_cache *cache,
435 struct cachefiles_object *object)
436{
437 struct dentry *dir;
438 int ret;
439
David Howellsc61ea312010-05-11 16:51:39 +0100440 _enter(",OBJ%x{%p}", object->fscache.debug_id, object->dentry);
David Howells9ae326a2009-04-03 16:42:41 +0100441
442 ASSERT(object->dentry);
David Howells466b77b2015-03-17 22:26:21 +0000443 ASSERT(d_backing_inode(object->dentry));
David Howells9ae326a2009-04-03 16:42:41 +0100444 ASSERT(object->dentry->d_parent);
445
446 dir = dget_parent(object->dentry);
447
Al Viro59551022016-01-22 15:40:57 -0500448 inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
David Howells8f9941a2010-02-19 18:14:21 +0000449
David Howells182d9192015-02-19 23:47:31 +0000450 if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) {
David Howellsc61ea312010-05-11 16:51:39 +0100451 /* object allocation for the same key preemptively deleted this
452 * object's file so that it could create its own file */
453 _debug("object preemptively buried");
Al Viro59551022016-01-22 15:40:57 -0500454 inode_unlock(d_inode(dir));
David Howells8f9941a2010-02-19 18:14:21 +0000455 ret = 0;
David Howellsc61ea312010-05-11 16:51:39 +0100456 } else {
457 /* we need to check that our parent is _still_ our parent - it
458 * may have been renamed */
459 if (dir == object->dentry->d_parent) {
460 ret = cachefiles_bury_object(cache, dir,
David Howells182d9192015-02-19 23:47:31 +0000461 object->dentry, false,
462 FSCACHE_OBJECT_WAS_RETIRED);
David Howellsc61ea312010-05-11 16:51:39 +0100463 } else {
464 /* it got moved, presumably by cachefilesd culling it,
465 * so it's no longer in the key path and we can ignore
466 * it */
Al Viro59551022016-01-22 15:40:57 -0500467 inode_unlock(d_inode(dir));
David Howellsc61ea312010-05-11 16:51:39 +0100468 ret = 0;
469 }
David Howells8f9941a2010-02-19 18:14:21 +0000470 }
David Howells9ae326a2009-04-03 16:42:41 +0100471
472 dput(dir);
473 _leave(" = %d", ret);
474 return ret;
475}
476
477/*
478 * walk from the parent object to the child object through the backing
479 * filesystem, creating directories as we go
480 */
481int cachefiles_walk_to_object(struct cachefiles_object *parent,
482 struct cachefiles_object *object,
483 const char *key,
484 struct cachefiles_xattr *auxdata)
485{
486 struct cachefiles_cache *cache;
487 struct dentry *dir, *next = NULL;
David Howells82140442010-12-24 14:48:35 +0000488 struct path path;
David Howells9ae326a2009-04-03 16:42:41 +0100489 unsigned long start;
490 const char *name;
491 int ret, nlen;
492
David Howellsc61ea312010-05-11 16:51:39 +0100493 _enter("OBJ%x{%p},OBJ%x,%s,",
494 parent->fscache.debug_id, parent->dentry,
495 object->fscache.debug_id, key);
David Howells9ae326a2009-04-03 16:42:41 +0100496
497 cache = container_of(parent->fscache.cache,
498 struct cachefiles_cache, cache);
David Howells82140442010-12-24 14:48:35 +0000499 path.mnt = cache->mnt;
David Howells9ae326a2009-04-03 16:42:41 +0100500
501 ASSERT(parent->dentry);
David Howells466b77b2015-03-17 22:26:21 +0000502 ASSERT(d_backing_inode(parent->dentry));
David Howells9ae326a2009-04-03 16:42:41 +0100503
David Howellse36cb0b2015-01-29 12:02:35 +0000504 if (!(d_is_dir(parent->dentry))) {
David Howells9ae326a2009-04-03 16:42:41 +0100505 // TODO: convert file to dir
506 _leave("looking up in none directory");
507 return -ENOBUFS;
508 }
509
510 dir = dget(parent->dentry);
511
512advance:
513 /* attempt to transit the first directory component */
514 name = key;
515 nlen = strlen(key);
516
517 /* key ends in a double NUL */
518 key = key + nlen + 1;
519 if (!*key)
520 key = NULL;
521
522lookup_again:
523 /* search the current directory for the element name */
524 _debug("lookup '%s'", name);
525
Al Viro59551022016-01-22 15:40:57 -0500526 inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
David Howells9ae326a2009-04-03 16:42:41 +0100527
528 start = jiffies;
529 next = lookup_one_len(name, dir, nlen);
530 cachefiles_hist(cachefiles_lookup_histogram, start);
531 if (IS_ERR(next))
532 goto lookup_error;
533
David Howells466b77b2015-03-17 22:26:21 +0000534 _debug("next -> %p %s", next, d_backing_inode(next) ? "positive" : "negative");
David Howells9ae326a2009-04-03 16:42:41 +0100535
536 if (!key)
David Howells466b77b2015-03-17 22:26:21 +0000537 object->new = !d_backing_inode(next);
David Howells9ae326a2009-04-03 16:42:41 +0100538
539 /* if this element of the path doesn't exist, then the lookup phase
540 * failed, and we can release any readers in the certain knowledge that
541 * there's nothing for them to actually read */
David Howells466b77b2015-03-17 22:26:21 +0000542 if (d_is_negative(next))
David Howells9ae326a2009-04-03 16:42:41 +0100543 fscache_object_lookup_negative(&object->fscache);
544
545 /* we need to create the object if it's negative */
546 if (key || object->type == FSCACHE_COOKIE_TYPE_INDEX) {
547 /* index objects and intervening tree levels must be subdirs */
David Howells466b77b2015-03-17 22:26:21 +0000548 if (d_is_negative(next)) {
David Howells9ae326a2009-04-03 16:42:41 +0100549 ret = cachefiles_has_space(cache, 1, 0);
550 if (ret < 0)
David Howells182d9192015-02-19 23:47:31 +0000551 goto no_space_error;
David Howells9ae326a2009-04-03 16:42:41 +0100552
David Howells82140442010-12-24 14:48:35 +0000553 path.dentry = dir;
554 ret = security_path_mkdir(&path, next, 0);
555 if (ret < 0)
556 goto create_error;
David Howells9ae326a2009-04-03 16:42:41 +0100557 start = jiffies;
David Howells5153bc82015-03-06 14:08:58 +0000558 ret = vfs_mkdir(d_inode(dir), next, 0);
David Howells9ae326a2009-04-03 16:42:41 +0100559 cachefiles_hist(cachefiles_mkdir_histogram, start);
560 if (ret < 0)
561 goto create_error;
562
David Howells466b77b2015-03-17 22:26:21 +0000563 ASSERT(d_backing_inode(next));
David Howells9ae326a2009-04-03 16:42:41 +0100564
565 _debug("mkdir -> %p{%p{ino=%lu}}",
David Howells466b77b2015-03-17 22:26:21 +0000566 next, d_backing_inode(next), d_backing_inode(next)->i_ino);
David Howells9ae326a2009-04-03 16:42:41 +0100567
David Howellsce40fa72015-01-29 12:02:36 +0000568 } else if (!d_can_lookup(next)) {
Fabian Frederick6ff66ac2014-09-25 16:05:27 -0700569 pr_err("inode %lu is not a directory\n",
David Howells466b77b2015-03-17 22:26:21 +0000570 d_backing_inode(next)->i_ino);
David Howells9ae326a2009-04-03 16:42:41 +0100571 ret = -ENOBUFS;
572 goto error;
573 }
574
575 } else {
576 /* non-index objects start out life as files */
David Howells466b77b2015-03-17 22:26:21 +0000577 if (d_is_negative(next)) {
David Howells9ae326a2009-04-03 16:42:41 +0100578 ret = cachefiles_has_space(cache, 1, 0);
579 if (ret < 0)
David Howells182d9192015-02-19 23:47:31 +0000580 goto no_space_error;
David Howells9ae326a2009-04-03 16:42:41 +0100581
David Howells82140442010-12-24 14:48:35 +0000582 path.dentry = dir;
583 ret = security_path_mknod(&path, next, S_IFREG, 0);
584 if (ret < 0)
585 goto create_error;
David Howells9ae326a2009-04-03 16:42:41 +0100586 start = jiffies;
David Howells5153bc82015-03-06 14:08:58 +0000587 ret = vfs_create(d_inode(dir), next, S_IFREG, true);
David Howells9ae326a2009-04-03 16:42:41 +0100588 cachefiles_hist(cachefiles_create_histogram, start);
589 if (ret < 0)
590 goto create_error;
591
David Howells466b77b2015-03-17 22:26:21 +0000592 ASSERT(d_backing_inode(next));
David Howells9ae326a2009-04-03 16:42:41 +0100593
594 _debug("create -> %p{%p{ino=%lu}}",
David Howells466b77b2015-03-17 22:26:21 +0000595 next, d_backing_inode(next), d_backing_inode(next)->i_ino);
David Howells9ae326a2009-04-03 16:42:41 +0100596
David Howellsce40fa72015-01-29 12:02:36 +0000597 } else if (!d_can_lookup(next) &&
David Howellse36cb0b2015-01-29 12:02:35 +0000598 !d_is_reg(next)
David Howells9ae326a2009-04-03 16:42:41 +0100599 ) {
Fabian Frederick6ff66ac2014-09-25 16:05:27 -0700600 pr_err("inode %lu is not a file or directory\n",
David Howells466b77b2015-03-17 22:26:21 +0000601 d_backing_inode(next)->i_ino);
David Howells9ae326a2009-04-03 16:42:41 +0100602 ret = -ENOBUFS;
603 goto error;
604 }
605 }
606
607 /* process the next component */
608 if (key) {
609 _debug("advance");
Al Viro59551022016-01-22 15:40:57 -0500610 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100611 dput(dir);
612 dir = next;
613 next = NULL;
614 goto advance;
615 }
616
617 /* we've found the object we were looking for */
618 object->dentry = next;
619
620 /* if we've found that the terminal object exists, then we need to
621 * check its attributes and delete it if it's out of date */
622 if (!object->new) {
Al Viroa4555892014-10-21 20:11:25 -0400623 _debug("validate '%pd'", next);
David Howells9ae326a2009-04-03 16:42:41 +0100624
625 ret = cachefiles_check_object_xattr(object, auxdata);
626 if (ret == -ESTALE) {
627 /* delete the object (the deleter drops the directory
628 * mutex) */
629 object->dentry = NULL;
630
David Howells182d9192015-02-19 23:47:31 +0000631 ret = cachefiles_bury_object(cache, dir, next, true,
632 FSCACHE_OBJECT_IS_STALE);
David Howells9ae326a2009-04-03 16:42:41 +0100633 dput(next);
634 next = NULL;
635
636 if (ret < 0)
637 goto delete_error;
638
639 _debug("redo lookup");
David Howells182d9192015-02-19 23:47:31 +0000640 fscache_object_retrying_stale(&object->fscache);
David Howells9ae326a2009-04-03 16:42:41 +0100641 goto lookup_again;
642 }
643 }
644
645 /* note that we're now using this object */
David Howellsfee096d2009-11-19 18:12:05 +0000646 ret = cachefiles_mark_object_active(cache, object);
David Howells9ae326a2009-04-03 16:42:41 +0100647
Al Viro59551022016-01-22 15:40:57 -0500648 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100649 dput(dir);
650 dir = NULL;
651
David Howellsfee096d2009-11-19 18:12:05 +0000652 if (ret == -ETIMEDOUT)
653 goto mark_active_timed_out;
654
David Howells9ae326a2009-04-03 16:42:41 +0100655 _debug("=== OBTAINED_OBJECT ===");
656
657 if (object->new) {
658 /* attach data to a newly constructed terminal object */
659 ret = cachefiles_set_object_xattr(object, auxdata);
660 if (ret < 0)
661 goto check_error;
662 } else {
663 /* always update the atime on an object we've just looked up
664 * (this is used to keep track of culling, and atimes are only
665 * updated by read, write and readdir but not lookup or
666 * open) */
Al Viro68ac1232012-03-15 08:21:57 -0400667 path.dentry = next;
668 touch_atime(&path);
David Howells9ae326a2009-04-03 16:42:41 +0100669 }
670
671 /* open a file interface onto a data file */
672 if (object->type != FSCACHE_COOKIE_TYPE_INDEX) {
David Howellse36cb0b2015-01-29 12:02:35 +0000673 if (d_is_reg(object->dentry)) {
David Howells9ae326a2009-04-03 16:42:41 +0100674 const struct address_space_operations *aops;
675
676 ret = -EPERM;
David Howells466b77b2015-03-17 22:26:21 +0000677 aops = d_backing_inode(object->dentry)->i_mapping->a_ops;
David Howells9ae326a2009-04-03 16:42:41 +0100678 if (!aops->bmap)
679 goto check_error;
NeilBrown95201a42015-11-04 15:20:34 +0000680 if (object->dentry->d_sb->s_blocksize > PAGE_SIZE)
681 goto check_error;
David Howells9ae326a2009-04-03 16:42:41 +0100682
683 object->backer = object->dentry;
684 } else {
685 BUG(); // TODO: open file in data-class subdir
686 }
687 }
688
689 object->new = 0;
690 fscache_obtained_object(&object->fscache);
691
David Howells466b77b2015-03-17 22:26:21 +0000692 _leave(" = 0 [%lu]", d_backing_inode(object->dentry)->i_ino);
David Howells9ae326a2009-04-03 16:42:41 +0100693 return 0;
694
David Howells182d9192015-02-19 23:47:31 +0000695no_space_error:
696 fscache_object_mark_killed(&object->fscache, FSCACHE_OBJECT_NO_SPACE);
David Howells9ae326a2009-04-03 16:42:41 +0100697create_error:
698 _debug("create error %d", ret);
699 if (ret == -EIO)
700 cachefiles_io_error(cache, "Create/mkdir failed");
701 goto error;
702
David Howellsfee096d2009-11-19 18:12:05 +0000703mark_active_timed_out:
704 _debug("mark active timed out");
705 goto release_dentry;
706
David Howells9ae326a2009-04-03 16:42:41 +0100707check_error:
708 _debug("check error %d", ret);
David Howellsa5b3a802016-02-01 16:43:04 +0000709 cachefiles_mark_object_inactive(cache, object);
David Howellsfee096d2009-11-19 18:12:05 +0000710release_dentry:
David Howells9ae326a2009-04-03 16:42:41 +0100711 dput(object->dentry);
712 object->dentry = NULL;
713 goto error_out;
714
715delete_error:
716 _debug("delete error %d", ret);
717 goto error_out2;
718
719lookup_error:
720 _debug("lookup error %ld", PTR_ERR(next));
721 ret = PTR_ERR(next);
722 if (ret == -EIO)
723 cachefiles_io_error(cache, "Lookup failed");
724 next = NULL;
725error:
Al Viro59551022016-01-22 15:40:57 -0500726 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100727 dput(next);
728error_out2:
729 dput(dir);
730error_out:
David Howells9ae326a2009-04-03 16:42:41 +0100731 _leave(" = error %d", -ret);
732 return ret;
733}
734
735/*
736 * get a subdirectory
737 */
738struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
739 struct dentry *dir,
740 const char *dirname)
741{
742 struct dentry *subdir;
743 unsigned long start;
David Howells82140442010-12-24 14:48:35 +0000744 struct path path;
David Howells9ae326a2009-04-03 16:42:41 +0100745 int ret;
746
747 _enter(",,%s", dirname);
748
749 /* search the current directory for the element name */
Al Viro59551022016-01-22 15:40:57 -0500750 inode_lock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100751
752 start = jiffies;
753 subdir = lookup_one_len(dirname, dir, strlen(dirname));
754 cachefiles_hist(cachefiles_lookup_histogram, start);
755 if (IS_ERR(subdir)) {
756 if (PTR_ERR(subdir) == -ENOMEM)
757 goto nomem_d_alloc;
758 goto lookup_error;
759 }
760
761 _debug("subdir -> %p %s",
David Howells466b77b2015-03-17 22:26:21 +0000762 subdir, d_backing_inode(subdir) ? "positive" : "negative");
David Howells9ae326a2009-04-03 16:42:41 +0100763
764 /* we need to create the subdir if it doesn't exist yet */
David Howells466b77b2015-03-17 22:26:21 +0000765 if (d_is_negative(subdir)) {
David Howells9ae326a2009-04-03 16:42:41 +0100766 ret = cachefiles_has_space(cache, 1, 0);
767 if (ret < 0)
768 goto mkdir_error;
769
770 _debug("attempt mkdir");
771
David Howells82140442010-12-24 14:48:35 +0000772 path.mnt = cache->mnt;
773 path.dentry = dir;
774 ret = security_path_mkdir(&path, subdir, 0700);
775 if (ret < 0)
776 goto mkdir_error;
David Howells5153bc82015-03-06 14:08:58 +0000777 ret = vfs_mkdir(d_inode(dir), subdir, 0700);
David Howells9ae326a2009-04-03 16:42:41 +0100778 if (ret < 0)
779 goto mkdir_error;
780
David Howells466b77b2015-03-17 22:26:21 +0000781 ASSERT(d_backing_inode(subdir));
David Howells9ae326a2009-04-03 16:42:41 +0100782
783 _debug("mkdir -> %p{%p{ino=%lu}}",
784 subdir,
David Howells466b77b2015-03-17 22:26:21 +0000785 d_backing_inode(subdir),
786 d_backing_inode(subdir)->i_ino);
David Howells9ae326a2009-04-03 16:42:41 +0100787 }
788
Al Viro59551022016-01-22 15:40:57 -0500789 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100790
791 /* we need to make sure the subdir is a directory */
David Howells466b77b2015-03-17 22:26:21 +0000792 ASSERT(d_backing_inode(subdir));
David Howells9ae326a2009-04-03 16:42:41 +0100793
David Howellsce40fa72015-01-29 12:02:36 +0000794 if (!d_can_lookup(subdir)) {
Fabian Frederick6ff66ac2014-09-25 16:05:27 -0700795 pr_err("%s is not a directory\n", dirname);
David Howells9ae326a2009-04-03 16:42:41 +0100796 ret = -EIO;
797 goto check_error;
798 }
799
800 ret = -EPERM;
David Howells466b77b2015-03-17 22:26:21 +0000801 if (!d_backing_inode(subdir)->i_op->setxattr ||
802 !d_backing_inode(subdir)->i_op->getxattr ||
803 !d_backing_inode(subdir)->i_op->lookup ||
804 !d_backing_inode(subdir)->i_op->mkdir ||
805 !d_backing_inode(subdir)->i_op->create ||
806 (!d_backing_inode(subdir)->i_op->rename &&
807 !d_backing_inode(subdir)->i_op->rename2) ||
808 !d_backing_inode(subdir)->i_op->rmdir ||
809 !d_backing_inode(subdir)->i_op->unlink)
David Howells9ae326a2009-04-03 16:42:41 +0100810 goto check_error;
811
David Howells466b77b2015-03-17 22:26:21 +0000812 _leave(" = [%lu]", d_backing_inode(subdir)->i_ino);
David Howells9ae326a2009-04-03 16:42:41 +0100813 return subdir;
814
815check_error:
816 dput(subdir);
817 _leave(" = %d [check]", ret);
818 return ERR_PTR(ret);
819
820mkdir_error:
Al Viro59551022016-01-22 15:40:57 -0500821 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100822 dput(subdir);
Fabian Frederick6ff66ac2014-09-25 16:05:27 -0700823 pr_err("mkdir %s failed with error %d\n", dirname, ret);
David Howells9ae326a2009-04-03 16:42:41 +0100824 return ERR_PTR(ret);
825
826lookup_error:
Al Viro59551022016-01-22 15:40:57 -0500827 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100828 ret = PTR_ERR(subdir);
Fabian Frederick6ff66ac2014-09-25 16:05:27 -0700829 pr_err("Lookup %s failed with error %d\n", dirname, ret);
David Howells9ae326a2009-04-03 16:42:41 +0100830 return ERR_PTR(ret);
831
832nomem_d_alloc:
Al Viro59551022016-01-22 15:40:57 -0500833 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100834 _leave(" = -ENOMEM");
835 return ERR_PTR(-ENOMEM);
836}
837
838/*
839 * find out if an object is in use or not
840 * - if finds object and it's not in use:
841 * - returns a pointer to the object and a reference on it
842 * - returns with the directory locked
843 */
844static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache,
845 struct dentry *dir,
846 char *filename)
847{
848 struct cachefiles_object *object;
849 struct rb_node *_n;
850 struct dentry *victim;
851 unsigned long start;
852 int ret;
853
Al Viroa4555892014-10-21 20:11:25 -0400854 //_enter(",%pd/,%s",
855 // dir, filename);
David Howells9ae326a2009-04-03 16:42:41 +0100856
857 /* look up the victim */
Al Viro59551022016-01-22 15:40:57 -0500858 inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
David Howells9ae326a2009-04-03 16:42:41 +0100859
860 start = jiffies;
861 victim = lookup_one_len(filename, dir, strlen(filename));
862 cachefiles_hist(cachefiles_lookup_histogram, start);
863 if (IS_ERR(victim))
864 goto lookup_error;
865
866 //_debug("victim -> %p %s",
David Howells466b77b2015-03-17 22:26:21 +0000867 // victim, d_backing_inode(victim) ? "positive" : "negative");
David Howells9ae326a2009-04-03 16:42:41 +0100868
869 /* if the object is no longer there then we probably retired the object
870 * at the netfs's request whilst the cull was in progress
871 */
David Howells466b77b2015-03-17 22:26:21 +0000872 if (d_is_negative(victim)) {
Al Viro59551022016-01-22 15:40:57 -0500873 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100874 dput(victim);
875 _leave(" = -ENOENT [absent]");
876 return ERR_PTR(-ENOENT);
877 }
878
879 /* check to see if we're using this object */
880 read_lock(&cache->active_lock);
881
882 _n = cache->active_nodes.rb_node;
883
884 while (_n) {
885 object = rb_entry(_n, struct cachefiles_object, active_node);
886
887 if (object->dentry > victim)
888 _n = _n->rb_left;
889 else if (object->dentry < victim)
890 _n = _n->rb_right;
891 else
892 goto object_in_use;
893 }
894
895 read_unlock(&cache->active_lock);
896
897 //_leave(" = %p", victim);
898 return victim;
899
900object_in_use:
901 read_unlock(&cache->active_lock);
Al Viro59551022016-01-22 15:40:57 -0500902 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100903 dput(victim);
904 //_leave(" = -EBUSY [in use]");
905 return ERR_PTR(-EBUSY);
906
907lookup_error:
Al Viro59551022016-01-22 15:40:57 -0500908 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100909 ret = PTR_ERR(victim);
910 if (ret == -ENOENT) {
911 /* file or dir now absent - probably retired by netfs */
912 _leave(" = -ESTALE [absent]");
913 return ERR_PTR(-ESTALE);
914 }
915
916 if (ret == -EIO) {
917 cachefiles_io_error(cache, "Lookup failed");
918 } else if (ret != -ENOMEM) {
Fabian Frederick6ff66ac2014-09-25 16:05:27 -0700919 pr_err("Internal error: %d\n", ret);
David Howells9ae326a2009-04-03 16:42:41 +0100920 ret = -EIO;
921 }
922
923 _leave(" = %d", ret);
924 return ERR_PTR(ret);
925}
926
927/*
928 * cull an object if it's not in use
929 * - called only by cache manager daemon
930 */
931int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
932 char *filename)
933{
934 struct dentry *victim;
935 int ret;
936
Al Viroa4555892014-10-21 20:11:25 -0400937 _enter(",%pd/,%s", dir, filename);
David Howells9ae326a2009-04-03 16:42:41 +0100938
939 victim = cachefiles_check_active(cache, dir, filename);
940 if (IS_ERR(victim))
941 return PTR_ERR(victim);
942
943 _debug("victim -> %p %s",
David Howells466b77b2015-03-17 22:26:21 +0000944 victim, d_backing_inode(victim) ? "positive" : "negative");
David Howells9ae326a2009-04-03 16:42:41 +0100945
946 /* okay... the victim is not being used so we can cull it
947 * - start by marking it as stale
948 */
949 _debug("victim is cullable");
950
951 ret = cachefiles_remove_object_xattr(cache, victim);
952 if (ret < 0)
953 goto error_unlock;
954
955 /* actually remove the victim (drops the dir mutex) */
956 _debug("bury");
957
David Howells182d9192015-02-19 23:47:31 +0000958 ret = cachefiles_bury_object(cache, dir, victim, false,
959 FSCACHE_OBJECT_WAS_CULLED);
David Howells9ae326a2009-04-03 16:42:41 +0100960 if (ret < 0)
961 goto error;
962
963 dput(victim);
964 _leave(" = 0");
965 return 0;
966
967error_unlock:
Al Viro59551022016-01-22 15:40:57 -0500968 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +0100969error:
970 dput(victim);
971 if (ret == -ENOENT) {
972 /* file or dir now absent - probably retired by netfs */
973 _leave(" = -ESTALE [absent]");
974 return -ESTALE;
975 }
976
977 if (ret != -ENOMEM) {
Fabian Frederick6ff66ac2014-09-25 16:05:27 -0700978 pr_err("Internal error: %d\n", ret);
David Howells9ae326a2009-04-03 16:42:41 +0100979 ret = -EIO;
980 }
981
982 _leave(" = %d", ret);
983 return ret;
984}
985
986/*
987 * find out if an object is in use or not
988 * - called only by cache manager daemon
989 * - returns -EBUSY or 0 to indicate whether an object is in use or not
990 */
991int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir,
992 char *filename)
993{
994 struct dentry *victim;
995
Al Viroa4555892014-10-21 20:11:25 -0400996 //_enter(",%pd/,%s",
997 // dir, filename);
David Howells9ae326a2009-04-03 16:42:41 +0100998
999 victim = cachefiles_check_active(cache, dir, filename);
1000 if (IS_ERR(victim))
1001 return PTR_ERR(victim);
1002
Al Viro59551022016-01-22 15:40:57 -05001003 inode_unlock(d_inode(dir));
David Howells9ae326a2009-04-03 16:42:41 +01001004 dput(victim);
1005 //_leave(" = 0");
1006 return 0;
1007}