Commit | Line | Data |
---|---|---|
e0e72660 | 1 | /* |
f7c3ffd7 | 2 | * Copyright (C) 2020 - Jérémie Galarneau <jeremie.galarneau@efficios.com> |
e0e72660 JG |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License, version 2 only, as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
16 | */ | |
17 | ||
5c1f54d1 JG |
18 | #include <common/defaults.h> |
19 | #include <common/error.h> | |
20 | #include <common/hashtable/utils.h> | |
21 | #include <common/macros.h> | |
f7c3ffd7 JG |
22 | #include <common/optional.h> |
23 | #include <common/string-utils/format.h> | |
24 | #include <common/utils.h> | |
5c1f54d1 JG |
25 | #include <inttypes.h> |
26 | #include <lttng/constant.h> | |
e0e72660 | 27 | #include <sys/stat.h> |
5c1f54d1 | 28 | #include <sys/types.h> |
e0e72660 | 29 | #include <unistd.h> |
e0e72660 | 30 | #include <urcu.h> |
e0e72660 | 31 | #include <urcu/rculfhash.h> |
5c1f54d1 | 32 | #include <urcu/ref.h> |
e0e72660 JG |
33 | |
34 | #include "inode.h" | |
35 | ||
36 | struct inode_id { | |
37 | dev_t device; | |
38 | ino_t inode; | |
39 | }; | |
40 | ||
41 | struct lttng_inode_registry { | |
42 | /* Hashtable of inode_id to lttng_inode. */ | |
43 | struct cds_lfht *inodes; | |
44 | }; | |
45 | ||
46 | struct lttng_inode { | |
47 | struct inode_id id; | |
e0e72660 JG |
48 | /* Node in the lttng_inode_registry's ht. */ |
49 | struct cds_lfht_node registry_node; | |
50 | /* Weak reference to ht containing the node. */ | |
51 | struct cds_lfht *registry_ht; | |
52 | struct urcu_ref ref; | |
53 | struct rcu_head rcu_head; | |
f7c3ffd7 JG |
54 | /* Location from which this file can be opened. */ |
55 | struct { | |
56 | struct lttng_directory_handle *directory_handle; | |
57 | char *path; | |
58 | } location; | |
59 | /* Unlink the underlying file at the release of the inode. */ | |
60 | bool unlink_pending; | |
61 | LTTNG_OPTIONAL(unsigned int) unlinked_id; | |
62 | /* Weak reference. */ | |
63 | struct lttng_unlinked_file_pool *unlinked_file_pool; | |
64 | }; | |
65 | ||
66 | struct lttng_unlinked_file_pool { | |
67 | struct lttng_directory_handle *unlink_directory_handle; | |
68 | char *unlink_directory_path; | |
69 | unsigned int file_count; | |
70 | unsigned int next_id; | |
e0e72660 JG |
71 | }; |
72 | ||
73 | static struct { | |
74 | pthread_mutex_t lock; | |
75 | bool initialized; | |
76 | unsigned long value; | |
77 | } seed = { | |
5c1f54d1 | 78 | .lock = PTHREAD_MUTEX_INITIALIZER, |
e0e72660 JG |
79 | }; |
80 | ||
f7c3ffd7 | 81 | static unsigned long lttng_inode_id_hash(const struct inode_id *id) |
e0e72660 JG |
82 | { |
83 | uint64_t device = id->device, inode_no = id->inode; | |
84 | ||
5c1f54d1 JG |
85 | return hash_key_u64(&device, seed.value) ^ |
86 | hash_key_u64(&inode_no, seed.value); | |
e0e72660 JG |
87 | } |
88 | ||
5c1f54d1 | 89 | static int lttng_inode_match(struct cds_lfht_node *node, const void *key) |
e0e72660 JG |
90 | { |
91 | const struct inode_id *id = key; | |
f7c3ffd7 | 92 | const struct lttng_inode *inode = caa_container_of( |
5c1f54d1 | 93 | node, struct lttng_inode, registry_node); |
e0e72660 JG |
94 | |
95 | return inode->id.device == id->device && inode->id.inode == id->inode; | |
96 | } | |
97 | ||
f7c3ffd7 | 98 | static void lttng_inode_free(struct rcu_head *head) |
e0e72660 | 99 | { |
5c1f54d1 JG |
100 | struct lttng_inode *inode = |
101 | caa_container_of(head, struct lttng_inode, rcu_head); | |
e0e72660 | 102 | |
e0e72660 JG |
103 | free(inode); |
104 | } | |
105 | ||
f7c3ffd7 JG |
106 | static int lttng_unlinked_file_pool_add_inode( |
107 | struct lttng_unlinked_file_pool *pool, | |
108 | struct lttng_inode *inode) | |
109 | { | |
110 | int ret; | |
111 | const unsigned int unlinked_id = pool->next_id++; | |
112 | char *inode_unlinked_name; | |
113 | bool reference_acquired; | |
114 | ||
115 | DBG("Adding inode of %s to unlinked file pool as id %u", | |
116 | inode->location.path, unlinked_id); | |
117 | ret = asprintf(&inode_unlinked_name, "%u", unlinked_id); | |
118 | if (ret < 0) { | |
119 | ERR("Failed to format unlinked inode name"); | |
120 | ret = -1; | |
121 | goto end; | |
122 | } | |
123 | ||
124 | if (pool->file_count == 0) { | |
125 | DBG("Creating unlinked files directory at %s", | |
126 | pool->unlink_directory_path); | |
127 | assert(!pool->unlink_directory_handle); | |
128 | ret = utils_mkdir(pool->unlink_directory_path, | |
129 | S_IRWXU | S_IRWXG, -1, -1); | |
130 | if (ret) { | |
131 | if (errno == EEXIST) { | |
132 | /* | |
133 | * Unexpected (previous crash?), but not an | |
134 | * error. | |
135 | */ | |
136 | DBG("Unlinked file directory \"%s\" already exists", | |
137 | pool->unlink_directory_path); | |
138 | } else { | |
139 | PERROR("Failed to create unlinked files directory at %s", | |
140 | pool->unlink_directory_path); | |
141 | goto end; | |
142 | } | |
143 | } | |
144 | pool->unlink_directory_handle = lttng_directory_handle_create( | |
145 | pool->unlink_directory_path); | |
146 | } | |
147 | ||
148 | ret = lttng_directory_handle_rename(inode->location.directory_handle, | |
149 | inode->location.path, pool->unlink_directory_handle, | |
150 | inode_unlinked_name); | |
151 | if (ret) { | |
152 | goto end; | |
153 | } | |
154 | ||
155 | lttng_directory_handle_put(inode->location.directory_handle); | |
156 | inode->location.directory_handle = NULL; | |
157 | reference_acquired = lttng_directory_handle_get( | |
158 | pool->unlink_directory_handle); | |
159 | assert(reference_acquired); | |
160 | inode->location.directory_handle = pool->unlink_directory_handle; | |
161 | ||
162 | free(inode->location.path); | |
163 | inode->location.path = inode_unlinked_name; | |
164 | inode_unlinked_name = NULL; | |
165 | LTTNG_OPTIONAL_SET(&inode->unlinked_id, unlinked_id); | |
166 | pool->file_count++; | |
167 | end: | |
168 | free(inode_unlinked_name); | |
169 | return ret; | |
170 | } | |
171 | ||
172 | static int lttng_unlinked_file_pool_remove_inode( | |
173 | struct lttng_unlinked_file_pool *pool, | |
174 | struct lttng_inode *inode) | |
175 | { | |
176 | int ret; | |
177 | ||
178 | DBG("Removing inode with unlinked id %u from unlinked file pool", | |
179 | LTTNG_OPTIONAL_GET(inode->unlinked_id)); | |
180 | ||
181 | ret = lttng_directory_handle_unlink_file( | |
182 | inode->location.directory_handle, inode->location.path); | |
183 | if (ret) { | |
184 | PERROR("Failed to unlink file %s from unlinked file directory", | |
185 | inode->location.path); | |
186 | goto end; | |
187 | } | |
188 | free(inode->location.path); | |
189 | inode->location.path = NULL; | |
190 | lttng_directory_handle_put(inode->location.directory_handle); | |
191 | inode->location.directory_handle = NULL; | |
192 | ||
193 | pool->file_count--; | |
194 | if (pool->file_count == 0) { | |
195 | ret = utils_recursive_rmdir(pool->unlink_directory_path); | |
196 | if (ret) { | |
197 | /* | |
198 | * There is nothing the caller can do, don't report an | |
199 | * error except through logging. | |
200 | */ | |
201 | PERROR("Failed to remove unlinked files directory at %s", | |
202 | pool->unlink_directory_path); | |
203 | } | |
204 | lttng_directory_handle_put(pool->unlink_directory_handle); | |
205 | pool->unlink_directory_handle = NULL; | |
206 | } | |
207 | end: | |
208 | return ret; | |
209 | } | |
210 | ||
5c1f54d1 | 211 | static void lttng_inode_destroy(struct lttng_inode *inode) |
e0e72660 JG |
212 | { |
213 | if (!inode) { | |
214 | return; | |
215 | } | |
f7c3ffd7 JG |
216 | |
217 | rcu_read_lock(); | |
218 | cds_lfht_del(inode->registry_ht, &inode->registry_node); | |
219 | rcu_read_unlock(); | |
220 | ||
e0e72660 | 221 | if (inode->unlink_pending) { |
f7c3ffd7 | 222 | int ret; |
e0e72660 | 223 | |
f7c3ffd7 JG |
224 | assert(inode->location.directory_handle); |
225 | assert(inode->location.path); | |
226 | DBG("Removing %s from unlinked file pool", | |
227 | inode->location.path); | |
228 | ret = lttng_unlinked_file_pool_remove_inode(inode->unlinked_file_pool, inode); | |
e0e72660 | 229 | if (ret) { |
f7c3ffd7 | 230 | PERROR("Failed to unlink %s", inode->location.path); |
e0e72660 JG |
231 | } |
232 | } | |
f7c3ffd7 JG |
233 | |
234 | lttng_directory_handle_put( | |
235 | inode->location.directory_handle); | |
236 | inode->location.directory_handle = NULL; | |
237 | free(inode->location.path); | |
238 | inode->location.path = NULL; | |
239 | call_rcu(&inode->rcu_head, lttng_inode_free); | |
e0e72660 JG |
240 | } |
241 | ||
5c1f54d1 | 242 | static void lttng_inode_release(struct urcu_ref *ref) |
e0e72660 | 243 | { |
5c1f54d1 | 244 | lttng_inode_destroy(caa_container_of(ref, struct lttng_inode, ref)); |
e0e72660 JG |
245 | } |
246 | ||
5c1f54d1 | 247 | static void lttng_inode_get(struct lttng_inode *inode) |
e0e72660 JG |
248 | { |
249 | urcu_ref_get(&inode->ref); | |
250 | } | |
251 | ||
f7c3ffd7 JG |
252 | struct lttng_unlinked_file_pool *lttng_unlinked_file_pool_create( |
253 | const char *path) | |
254 | { | |
255 | struct lttng_unlinked_file_pool *pool = zmalloc(sizeof(*pool)); | |
256 | ||
257 | if (!path || *path != '/') { | |
258 | ERR("Unlinked file pool must be created with an absolute path, path = \"%s\"", | |
259 | path ? path : "NULL"); | |
260 | goto error; | |
261 | } | |
262 | ||
263 | pool->unlink_directory_path = strdup(path); | |
264 | if (!pool->unlink_directory_path) { | |
265 | PERROR("Failed to allocation unlinked file pool path"); | |
266 | goto error; | |
267 | } | |
268 | DBG("Unlinked file pool created at: %s", path); | |
269 | return pool; | |
270 | error: | |
271 | lttng_unlinked_file_pool_destroy(pool); | |
272 | return NULL; | |
273 | } | |
274 | ||
275 | void lttng_unlinked_file_pool_destroy( | |
276 | struct lttng_unlinked_file_pool *pool) | |
277 | { | |
278 | if (!pool) { | |
279 | return; | |
280 | } | |
281 | ||
282 | assert(pool->file_count == 0); | |
283 | lttng_directory_handle_put(pool->unlink_directory_handle); | |
284 | free(pool->unlink_directory_path); | |
285 | free(pool); | |
286 | } | |
287 | ||
e0e72660 JG |
288 | void lttng_inode_put(struct lttng_inode *inode) |
289 | { | |
290 | urcu_ref_put(&inode->ref, lttng_inode_release); | |
291 | } | |
292 | ||
f7c3ffd7 JG |
293 | void lttng_inode_get_location(struct lttng_inode *inode, |
294 | const struct lttng_directory_handle **out_directory_handle, | |
295 | const char **out_path) | |
e0e72660 | 296 | { |
f7c3ffd7 JG |
297 | if (out_directory_handle) { |
298 | *out_directory_handle = inode->location.directory_handle; | |
299 | } | |
300 | if (out_path) { | |
301 | *out_path = inode->location.path; | |
302 | } | |
e0e72660 JG |
303 | } |
304 | ||
5c1f54d1 | 305 | int lttng_inode_rename( |
f7c3ffd7 JG |
306 | struct lttng_inode *inode, |
307 | struct lttng_directory_handle *old_directory_handle, | |
308 | const char *old_path, | |
309 | struct lttng_directory_handle *new_directory_handle, | |
310 | const char *new_path, | |
311 | bool overwrite) | |
e0e72660 JG |
312 | { |
313 | int ret = 0; | |
f7c3ffd7 JG |
314 | char *new_path_copy = strdup(new_path); |
315 | bool reference_acquired; | |
316 | ||
317 | DBG("Performing rename of inode from %s to %s with %s directory handles", | |
318 | old_path, new_path, | |
319 | lttng_directory_handle_equals(old_directory_handle, | |
320 | new_directory_handle) ? | |
321 | "identical" : | |
322 | "different"); | |
323 | ||
324 | if (!new_path_copy) { | |
325 | ret = -ENOMEM; | |
326 | goto end; | |
327 | } | |
e0e72660 JG |
328 | |
329 | if (inode->unlink_pending) { | |
f7c3ffd7 JG |
330 | WARN("An attempt to rename an unlinked file from %s to %s has been performed", |
331 | old_path, new_path); | |
e0e72660 JG |
332 | ret = -ENOENT; |
333 | goto end; | |
334 | } | |
335 | ||
336 | if (!overwrite) { | |
f7c3ffd7 | 337 | /* Verify that file doesn't exist. */ |
e0e72660 JG |
338 | struct stat statbuf; |
339 | ||
f7c3ffd7 JG |
340 | ret = lttng_directory_handle_stat( |
341 | new_directory_handle, new_path, &statbuf); | |
e0e72660 | 342 | if (ret == 0) { |
f7c3ffd7 JG |
343 | ERR("Refusing to rename %s as the destination already exists", |
344 | old_path); | |
e0e72660 JG |
345 | ret = -EEXIST; |
346 | goto end; | |
347 | } else if (ret < 0 && errno != ENOENT) { | |
348 | PERROR("Failed to stat() %s", new_path); | |
349 | ret = -errno; | |
350 | goto end; | |
351 | } | |
352 | } | |
353 | ||
f7c3ffd7 JG |
354 | ret = lttng_directory_handle_rename(old_directory_handle, old_path, |
355 | new_directory_handle, new_path); | |
e0e72660 | 356 | if (ret) { |
f7c3ffd7 | 357 | PERROR("Failed to rename file %s to %s", old_path, new_path); |
e0e72660 JG |
358 | ret = -errno; |
359 | goto end; | |
360 | } | |
361 | ||
f7c3ffd7 JG |
362 | reference_acquired = lttng_directory_handle_get(new_directory_handle); |
363 | assert(reference_acquired); | |
364 | lttng_directory_handle_put(inode->location.directory_handle); | |
365 | free(inode->location.path); | |
366 | inode->location.directory_handle = new_directory_handle; | |
367 | /* Ownership transferred. */ | |
368 | inode->location.path = new_path_copy; | |
e0e72660 JG |
369 | new_path_copy = NULL; |
370 | end: | |
371 | free(new_path_copy); | |
372 | return ret; | |
373 | } | |
374 | ||
f7c3ffd7 | 375 | int lttng_inode_unlink(struct lttng_inode *inode) |
e0e72660 JG |
376 | { |
377 | int ret = 0; | |
f7c3ffd7 JG |
378 | |
379 | DBG("Attempting unlink of inode %s", inode->location.path); | |
e0e72660 JG |
380 | |
381 | if (inode->unlink_pending) { | |
382 | WARN("An attempt to re-unlink %s has been performed, ignoring.", | |
f7c3ffd7 | 383 | inode->location.path); |
e0e72660 JG |
384 | ret = -ENOENT; |
385 | goto end; | |
386 | } | |
387 | ||
f7c3ffd7 JG |
388 | /* |
389 | * Move to the temporary "deleted" directory until all | |
390 | * references are released. | |
391 | */ | |
392 | ret = lttng_unlinked_file_pool_add_inode( | |
393 | inode->unlinked_file_pool, inode); | |
394 | if (ret) { | |
395 | PERROR("Failed to add inode \"%s\" to the unlinked file pool", | |
396 | inode->location.path); | |
e0e72660 JG |
397 | goto end; |
398 | } | |
f7c3ffd7 | 399 | inode->unlink_pending = true; |
e0e72660 JG |
400 | end: |
401 | return ret; | |
402 | } | |
403 | ||
5c1f54d1 | 404 | static struct lttng_inode *lttng_inode_create(const struct inode_id *id, |
f7c3ffd7 JG |
405 | struct cds_lfht *ht, |
406 | struct lttng_unlinked_file_pool *unlinked_file_pool, | |
407 | struct lttng_directory_handle *directory_handle, | |
408 | const char *path) | |
e0e72660 | 409 | { |
f7c3ffd7 JG |
410 | struct lttng_inode *inode = NULL; |
411 | char *path_copy; | |
412 | bool reference_acquired; | |
413 | ||
414 | path_copy = strdup(path); | |
415 | if (!path_copy) { | |
416 | goto end; | |
417 | } | |
e0e72660 | 418 | |
f7c3ffd7 JG |
419 | reference_acquired = lttng_directory_handle_get(directory_handle); |
420 | assert(reference_acquired); | |
421 | ||
422 | inode = zmalloc(sizeof(*inode)); | |
e0e72660 JG |
423 | if (!inode) { |
424 | goto end; | |
425 | } | |
426 | ||
427 | urcu_ref_init(&inode->ref); | |
428 | cds_lfht_node_init(&inode->registry_node); | |
429 | inode->id = *id; | |
e0e72660 | 430 | inode->registry_ht = ht; |
f7c3ffd7 JG |
431 | inode->unlinked_file_pool = unlinked_file_pool; |
432 | /* Ownership of path copy is transferred to inode. */ | |
433 | inode->location.path = path_copy; | |
434 | path_copy = NULL; | |
435 | inode->location.directory_handle = directory_handle; | |
e0e72660 | 436 | end: |
f7c3ffd7 | 437 | free(path_copy); |
e0e72660 | 438 | return inode; |
e0e72660 JG |
439 | } |
440 | ||
441 | struct lttng_inode_registry *lttng_inode_registry_create(void) | |
442 | { | |
443 | struct lttng_inode_registry *registry = zmalloc(sizeof(*registry)); | |
444 | ||
445 | if (!registry) { | |
446 | goto end; | |
447 | } | |
448 | ||
449 | pthread_mutex_lock(&seed.lock); | |
450 | if (!seed.initialized) { | |
451 | seed.value = (unsigned long) time(NULL); | |
452 | seed.initialized = true; | |
453 | } | |
454 | pthread_mutex_unlock(&seed.lock); | |
455 | ||
456 | registry->inodes = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, | |
457 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); | |
458 | if (!registry->inodes) { | |
459 | goto error; | |
460 | } | |
461 | end: | |
462 | return registry; | |
463 | error: | |
464 | lttng_inode_registry_destroy(registry); | |
465 | return NULL; | |
466 | } | |
467 | ||
468 | void lttng_inode_registry_destroy(struct lttng_inode_registry *registry) | |
469 | { | |
470 | if (!registry) { | |
471 | return; | |
472 | } | |
473 | if (registry->inodes) { | |
474 | int ret = cds_lfht_destroy(registry->inodes, NULL); | |
475 | ||
476 | assert(!ret); | |
477 | } | |
478 | free(registry); | |
479 | } | |
480 | ||
481 | struct lttng_inode *lttng_inode_registry_get_inode( | |
f7c3ffd7 JG |
482 | struct lttng_inode_registry *registry, |
483 | struct lttng_directory_handle *handle, | |
484 | const char *path, | |
485 | int fd, | |
486 | struct lttng_unlinked_file_pool *unlinked_file_pool) | |
e0e72660 JG |
487 | { |
488 | int ret; | |
489 | struct stat statbuf; | |
490 | struct inode_id id; | |
491 | struct cds_lfht_iter iter; | |
492 | struct cds_lfht_node *node; | |
493 | struct lttng_inode *inode = NULL; | |
494 | ||
495 | ret = fstat(fd, &statbuf); | |
496 | if (ret < 0) { | |
f7c3ffd7 | 497 | PERROR("stat() failed on fd %i", fd); |
e0e72660 JG |
498 | goto end; |
499 | } | |
500 | ||
501 | id.device = statbuf.st_dev; | |
502 | id.inode = statbuf.st_ino; | |
503 | ||
504 | rcu_read_lock(); | |
5c1f54d1 JG |
505 | cds_lfht_lookup(registry->inodes, lttng_inode_id_hash(&id), |
506 | lttng_inode_match, &id, &iter); | |
e0e72660 JG |
507 | node = cds_lfht_iter_get_node(&iter); |
508 | if (node) { | |
5c1f54d1 JG |
509 | inode = caa_container_of( |
510 | node, struct lttng_inode, registry_node); | |
e0e72660 JG |
511 | lttng_inode_get(inode); |
512 | goto end_unlock; | |
513 | } | |
514 | ||
f7c3ffd7 JG |
515 | inode = lttng_inode_create(&id, registry->inodes, unlinked_file_pool, |
516 | handle, path); | |
e0e72660 | 517 | node = cds_lfht_add_unique(registry->inodes, |
5c1f54d1 JG |
518 | lttng_inode_id_hash(&inode->id), lttng_inode_match, |
519 | &inode->id, &inode->registry_node); | |
e0e72660 JG |
520 | assert(node == &inode->registry_node); |
521 | end_unlock: | |
522 | rcu_read_unlock(); | |
523 | end: | |
524 | return inode; | |
525 | } |