2 * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 * SPDX-License-Identifier: GPL-2.0-only
8 #include <common/defaults.h>
9 #include <common/error.h>
10 #include <common/hashtable/utils.h>
11 #include <common/macros.h>
12 #include <common/optional.h>
13 #include <common/string-utils/format.h>
14 #include <common/utils.h>
16 #include <lttng/constant.h>
18 #include <sys/types.h>
21 #include <urcu/rculfhash.h>
31 struct lttng_inode_registry
{
32 /* Hashtable of inode_id to lttng_inode. */
33 struct cds_lfht
*inodes
;
38 /* Node in the lttng_inode_registry's ht. */
39 struct cds_lfht_node registry_node
;
40 /* Weak reference to ht containing the node. */
41 struct cds_lfht
*registry_ht
;
43 struct rcu_head rcu_head
;
44 /* Location from which this file can be opened. */
46 struct lttng_directory_handle
*directory_handle
;
49 /* Unlink the underlying file at the release of the inode. */
51 LTTNG_OPTIONAL(unsigned int) unlinked_id
;
53 struct lttng_unlinked_file_pool
*unlinked_file_pool
;
56 struct lttng_unlinked_file_pool
{
57 struct lttng_directory_handle
*unlink_directory_handle
;
58 char *unlink_directory_path
;
59 unsigned int file_count
;
68 .lock
= PTHREAD_MUTEX_INITIALIZER
,
73 static unsigned long lttng_inode_id_hash(const struct inode_id
*id
)
75 uint64_t device
= id
->device
, inode_no
= id
->inode
;
77 return hash_key_u64(&device
, seed
.value
) ^
78 hash_key_u64(&inode_no
, seed
.value
);
81 static int lttng_inode_match(struct cds_lfht_node
*node
, const void *key
)
83 const struct inode_id
*id
= (inode_id
*) key
;
84 const struct lttng_inode
*inode
= caa_container_of(
85 node
, struct lttng_inode
, registry_node
);
87 return inode
->id
.device
== id
->device
&& inode
->id
.inode
== id
->inode
;
90 static void lttng_inode_free(struct rcu_head
*head
)
92 struct lttng_inode
*inode
=
93 caa_container_of(head
, struct lttng_inode
, rcu_head
);
98 static int lttng_unlinked_file_pool_add_inode(
99 struct lttng_unlinked_file_pool
*pool
,
100 struct lttng_inode
*inode
)
103 const unsigned int unlinked_id
= pool
->next_id
++;
104 char *inode_unlinked_name
;
105 bool reference_acquired
;
107 DBG("Adding inode of %s to unlinked file pool as id %u",
108 inode
->location
.path
, unlinked_id
);
109 ret
= asprintf(&inode_unlinked_name
, "%u", unlinked_id
);
111 ERR("Failed to format unlinked inode name");
116 if (pool
->file_count
== 0) {
117 DBG("Creating unlinked files directory at %s",
118 pool
->unlink_directory_path
);
119 LTTNG_ASSERT(!pool
->unlink_directory_handle
);
120 ret
= utils_mkdir(pool
->unlink_directory_path
,
121 S_IRWXU
| S_IRWXG
, -1, -1);
123 if (errno
== EEXIST
) {
125 * Unexpected (previous crash?), but not an
128 DBG("Unlinked file directory \"%s\" already exists",
129 pool
->unlink_directory_path
);
131 PERROR("Failed to create unlinked files directory at %s",
132 pool
->unlink_directory_path
);
136 pool
->unlink_directory_handle
= lttng_directory_handle_create(
137 pool
->unlink_directory_path
);
138 if (!pool
->unlink_directory_handle
) {
139 ERR("Failed to create directory handle to unlinked file pool at %s",
140 pool
->unlink_directory_path
);
146 ret
= lttng_directory_handle_rename(inode
->location
.directory_handle
,
147 inode
->location
.path
, pool
->unlink_directory_handle
,
148 inode_unlinked_name
);
153 lttng_directory_handle_put(inode
->location
.directory_handle
);
154 inode
->location
.directory_handle
= NULL
;
155 reference_acquired
= lttng_directory_handle_get(
156 pool
->unlink_directory_handle
);
157 LTTNG_ASSERT(reference_acquired
);
158 inode
->location
.directory_handle
= pool
->unlink_directory_handle
;
160 free(inode
->location
.path
);
161 inode
->location
.path
= inode_unlinked_name
;
162 inode_unlinked_name
= NULL
;
163 LTTNG_OPTIONAL_SET(&inode
->unlinked_id
, unlinked_id
);
166 free(inode_unlinked_name
);
170 static int lttng_unlinked_file_pool_remove_inode(
171 struct lttng_unlinked_file_pool
*pool
,
172 struct lttng_inode
*inode
)
176 DBG("Removing inode with unlinked id %u from unlinked file pool",
177 LTTNG_OPTIONAL_GET(inode
->unlinked_id
));
179 ret
= lttng_directory_handle_unlink_file(
180 inode
->location
.directory_handle
, inode
->location
.path
);
182 PERROR("Failed to unlink file %s from unlinked file directory",
183 inode
->location
.path
);
186 free(inode
->location
.path
);
187 inode
->location
.path
= NULL
;
188 lttng_directory_handle_put(inode
->location
.directory_handle
);
189 inode
->location
.directory_handle
= NULL
;
192 if (pool
->file_count
== 0) {
193 ret
= utils_recursive_rmdir(pool
->unlink_directory_path
);
196 * There is nothing the caller can do, don't report an
197 * error except through logging.
199 PERROR("Failed to remove unlinked files directory at %s",
200 pool
->unlink_directory_path
);
202 lttng_directory_handle_put(pool
->unlink_directory_handle
);
203 pool
->unlink_directory_handle
= NULL
;
209 static void lttng_inode_destroy(struct lttng_inode
*inode
)
216 cds_lfht_del(inode
->registry_ht
, &inode
->registry_node
);
219 if (inode
->unlink_pending
) {
222 LTTNG_ASSERT(inode
->location
.directory_handle
);
223 LTTNG_ASSERT(inode
->location
.path
);
224 DBG("Removing %s from unlinked file pool",
225 inode
->location
.path
);
226 ret
= lttng_unlinked_file_pool_remove_inode(inode
->unlinked_file_pool
, inode
);
228 PERROR("Failed to unlink %s", inode
->location
.path
);
232 lttng_directory_handle_put(
233 inode
->location
.directory_handle
);
234 inode
->location
.directory_handle
= NULL
;
235 free(inode
->location
.path
);
236 inode
->location
.path
= NULL
;
237 call_rcu(&inode
->rcu_head
, lttng_inode_free
);
240 static void lttng_inode_release(struct urcu_ref
*ref
)
242 lttng_inode_destroy(caa_container_of(ref
, struct lttng_inode
, ref
));
245 static void lttng_inode_get(struct lttng_inode
*inode
)
247 urcu_ref_get(&inode
->ref
);
250 struct lttng_unlinked_file_pool
*lttng_unlinked_file_pool_create(
253 struct lttng_unlinked_file_pool
*pool
= (lttng_unlinked_file_pool
*) zmalloc(sizeof(*pool
));
259 if (!path
|| *path
!= '/') {
260 ERR("Unlinked file pool must be created with an absolute path, path = \"%s\"",
261 path
? path
: "NULL");
265 pool
->unlink_directory_path
= strdup(path
);
266 if (!pool
->unlink_directory_path
) {
267 PERROR("Failed to allocation unlinked file pool path");
270 DBG("Unlinked file pool created at: %s", path
);
273 lttng_unlinked_file_pool_destroy(pool
);
277 void lttng_unlinked_file_pool_destroy(
278 struct lttng_unlinked_file_pool
*pool
)
284 LTTNG_ASSERT(pool
->file_count
== 0);
285 lttng_directory_handle_put(pool
->unlink_directory_handle
);
286 free(pool
->unlink_directory_path
);
290 void lttng_inode_put(struct lttng_inode
*inode
)
292 urcu_ref_put(&inode
->ref
, lttng_inode_release
);
295 struct lttng_directory_handle
*
296 lttng_inode_get_location_directory_handle(
297 struct lttng_inode
*inode
)
299 if (inode
->location
.directory_handle
) {
300 const bool reference_acquired
= lttng_directory_handle_get(
301 inode
->location
.directory_handle
);
303 LTTNG_ASSERT(reference_acquired
);
305 return inode
->location
.directory_handle
;
308 void lttng_inode_borrow_location(struct lttng_inode
*inode
,
309 const struct lttng_directory_handle
**out_directory_handle
,
310 const char **out_path
)
312 if (out_directory_handle
) {
313 *out_directory_handle
= inode
->location
.directory_handle
;
316 *out_path
= inode
->location
.path
;
320 int lttng_inode_rename(
321 struct lttng_inode
*inode
,
322 struct lttng_directory_handle
*old_directory_handle
,
323 const char *old_path
,
324 struct lttng_directory_handle
*new_directory_handle
,
325 const char *new_path
,
329 char *new_path_copy
= strdup(new_path
);
330 bool reference_acquired
;
332 DBG("Performing rename of inode from %s to %s with %s directory handles",
334 lttng_directory_handle_equals(old_directory_handle
,
335 new_directory_handle
) ?
339 if (!new_path_copy
) {
344 if (inode
->unlink_pending
) {
345 WARN("An attempt to rename an unlinked file from %s to %s has been performed",
352 /* Verify that file doesn't exist. */
355 ret
= lttng_directory_handle_stat(
356 new_directory_handle
, new_path
, &statbuf
);
358 ERR("Refusing to rename %s as the destination already exists",
362 } else if (ret
< 0 && errno
!= ENOENT
) {
363 PERROR("Failed to stat() %s", new_path
);
369 ret
= lttng_directory_handle_rename(old_directory_handle
, old_path
,
370 new_directory_handle
, new_path
);
372 PERROR("Failed to rename file %s to %s", old_path
, new_path
);
377 reference_acquired
= lttng_directory_handle_get(new_directory_handle
);
378 LTTNG_ASSERT(reference_acquired
);
379 lttng_directory_handle_put(inode
->location
.directory_handle
);
380 free(inode
->location
.path
);
381 inode
->location
.directory_handle
= new_directory_handle
;
382 /* Ownership transferred. */
383 inode
->location
.path
= new_path_copy
;
384 new_path_copy
= NULL
;
390 int lttng_inode_unlink(struct lttng_inode
*inode
)
394 DBG("Attempting unlink of inode %s", inode
->location
.path
);
396 if (inode
->unlink_pending
) {
397 WARN("An attempt to re-unlink %s has been performed, ignoring.",
398 inode
->location
.path
);
404 * Move to the temporary "deleted" directory until all
405 * references are released.
407 ret
= lttng_unlinked_file_pool_add_inode(
408 inode
->unlinked_file_pool
, inode
);
410 PERROR("Failed to add inode \"%s\" to the unlinked file pool",
411 inode
->location
.path
);
414 inode
->unlink_pending
= true;
419 static struct lttng_inode
*lttng_inode_create(const struct inode_id
*id
,
421 struct lttng_unlinked_file_pool
*unlinked_file_pool
,
422 struct lttng_directory_handle
*directory_handle
,
425 struct lttng_inode
*inode
= NULL
;
427 bool reference_acquired
;
429 path_copy
= strdup(path
);
434 reference_acquired
= lttng_directory_handle_get(directory_handle
);
435 LTTNG_ASSERT(reference_acquired
);
437 inode
= (lttng_inode
*) zmalloc(sizeof(*inode
));
442 urcu_ref_init(&inode
->ref
);
443 cds_lfht_node_init(&inode
->registry_node
);
445 inode
->registry_ht
= ht
;
446 inode
->unlinked_file_pool
= unlinked_file_pool
;
447 /* Ownership of path copy is transferred to inode. */
448 inode
->location
.path
= path_copy
;
450 inode
->location
.directory_handle
= directory_handle
;
456 struct lttng_inode_registry
*lttng_inode_registry_create(void)
458 struct lttng_inode_registry
*registry
= (lttng_inode_registry
*) zmalloc(sizeof(*registry
));
464 pthread_mutex_lock(&seed
.lock
);
465 if (!seed
.initialized
) {
466 seed
.value
= (unsigned long) time(NULL
);
467 seed
.initialized
= true;
469 pthread_mutex_unlock(&seed
.lock
);
471 registry
->inodes
= cds_lfht_new(DEFAULT_HT_SIZE
, 1, 0,
472 CDS_LFHT_AUTO_RESIZE
| CDS_LFHT_ACCOUNTING
, NULL
);
473 if (!registry
->inodes
) {
479 lttng_inode_registry_destroy(registry
);
483 void lttng_inode_registry_destroy(
484 struct lttng_inode_registry
*registry
)
489 if (registry
->inodes
) {
490 int ret
= cds_lfht_destroy(registry
->inodes
, NULL
);
497 struct lttng_inode
*lttng_inode_registry_get_inode(
498 struct lttng_inode_registry
*registry
,
499 struct lttng_directory_handle
*handle
,
502 struct lttng_unlinked_file_pool
*unlinked_file_pool
)
507 struct cds_lfht_iter iter
;
508 struct cds_lfht_node
*node
;
509 struct lttng_inode
*inode
= NULL
;
511 ret
= fstat(fd
, &statbuf
);
513 PERROR("stat() failed on fd %i", fd
);
517 id
.device
= statbuf
.st_dev
;
518 id
.inode
= statbuf
.st_ino
;
521 cds_lfht_lookup(registry
->inodes
, lttng_inode_id_hash(&id
),
522 lttng_inode_match
, &id
, &iter
);
523 node
= cds_lfht_iter_get_node(&iter
);
525 inode
= caa_container_of(
526 node
, struct lttng_inode
, registry_node
);
527 lttng_inode_get(inode
);
531 inode
= lttng_inode_create(&id
, registry
->inodes
, unlinked_file_pool
,
537 node
= cds_lfht_add_unique(registry
->inodes
,
538 lttng_inode_id_hash(&inode
->id
), lttng_inode_match
,
539 &inode
->id
, &inode
->registry_node
);
540 LTTNG_ASSERT(node
== &inode
->registry_node
);