+++ /dev/null
-/*
- * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#include <common/defaults.h>
-#include <common/error.h>
-#include <common/hashtable/utils.h>
-#include <common/macros.h>
-#include <inttypes.h>
-#include <lttng/constant.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <urcu.h>
-#include <urcu/rculfhash.h>
-#include <urcu/ref.h>
-
-#include "inode.h"
-
-struct inode_id {
- dev_t device;
- ino_t inode;
-};
-
-struct lttng_inode_registry {
- /* Hashtable of inode_id to lttng_inode. */
- struct cds_lfht *inodes;
-};
-
-struct lttng_inode {
- struct inode_id id;
- char *path;
- bool unlink_pending;
- /* Node in the lttng_inode_registry's ht. */
- struct cds_lfht_node registry_node;
- /* Weak reference to ht containing the node. */
- struct cds_lfht *registry_ht;
- struct urcu_ref ref;
- struct rcu_head rcu_head;
-};
-
-static struct {
- pthread_mutex_t lock;
- bool initialized;
- unsigned long value;
-} seed = {
- .lock = PTHREAD_MUTEX_INITIALIZER,
-};
-
-static unsigned long lttng_inode_id_hash(struct inode_id *id)
-{
- uint64_t device = id->device, inode_no = id->inode;
-
- return hash_key_u64(&device, seed.value) ^
- hash_key_u64(&inode_no, seed.value);
-}
-
-static int lttng_inode_match(struct cds_lfht_node *node, const void *key)
-{
- const struct inode_id *id = key;
- struct lttng_inode *inode = caa_container_of(
- node, struct lttng_inode, registry_node);
-
- return inode->id.device == id->device && inode->id.inode == id->inode;
-}
-
-static void lttng_inode_delete(struct rcu_head *head)
-{
- struct lttng_inode *inode =
- caa_container_of(head, struct lttng_inode, rcu_head);
-
- free(inode->path);
- free(inode);
-}
-
-static void lttng_inode_destroy(struct lttng_inode *inode)
-{
- if (!inode) {
- return;
- }
- if (inode->unlink_pending) {
- int ret = unlink(inode->path);
-
- DBG("Unlinking %s during lttng_inode destruction", inode->path);
- if (ret) {
- PERROR("Failed to unlink %s", inode->path);
- }
- }
- rcu_read_lock();
- cds_lfht_del(inode->registry_ht, &inode->registry_node);
- rcu_read_unlock();
- call_rcu(&inode->rcu_head, lttng_inode_delete);
-}
-
-static void lttng_inode_release(struct urcu_ref *ref)
-{
- lttng_inode_destroy(caa_container_of(ref, struct lttng_inode, ref));
-}
-
-static void lttng_inode_get(struct lttng_inode *inode)
-{
- urcu_ref_get(&inode->ref);
-}
-
-void lttng_inode_put(struct lttng_inode *inode)
-{
- urcu_ref_put(&inode->ref, lttng_inode_release);
-}
-
-const char *lttng_inode_get_path(const struct lttng_inode *inode)
-{
- return inode->path;
-}
-
-int lttng_inode_rename(
- struct lttng_inode *inode, const char *new_path, bool overwrite)
-{
- int ret = 0;
- char *new_path_copy = NULL;
-
- if (inode->unlink_pending) {
- WARN("An attempt to rename an unlinked file, %s to %s, has been performed",
- inode->path, new_path);
- ret = -ENOENT;
- goto end;
- }
-
- if (!overwrite) {
- struct stat statbuf;
-
- ret = stat(new_path, &statbuf);
- if (ret == 0) {
- ret = -EEXIST;
- goto end;
- } else if (ret < 0 && errno != ENOENT) {
- PERROR("Failed to stat() %s", new_path);
- ret = -errno;
- goto end;
- }
- }
-
- new_path_copy = strdup(new_path);
- if (!new_path_copy) {
- ERR("Failed to allocate storage for path %s", new_path);
- ret = -ENOMEM;
- goto end;
- }
-
- ret = rename(inode->path, new_path);
- if (ret) {
- PERROR("Failed to rename %s to %s", inode->path, new_path);
- ret = -errno;
- goto end;
- }
-
- free(inode->path);
- inode->path = new_path_copy;
- new_path_copy = NULL;
-end:
- free(new_path_copy);
- return ret;
-}
-
-int lttng_inode_defer_unlink(struct lttng_inode *inode)
-{
- int ret = 0;
- uint16_t i = 0;
- char suffix[sizeof("-deleted-65535")] = "-deleted";
- char new_path[LTTNG_PATH_MAX];
- size_t original_path_len = strlen(inode->path);
-
- if (inode->unlink_pending) {
- WARN("An attempt to re-unlink %s has been performed, ignoring.",
- inode->path);
- ret = -ENOENT;
- goto end;
- }
-
- ret = lttng_strncpy(new_path, inode->path, sizeof(new_path));
- if (ret < 0) {
- ret = -ENAMETOOLONG;
- goto end;
- }
-
- for (i = 0; i < UINT16_MAX; i++) {
- int p_ret;
-
- if (i != 0) {
- p_ret = snprintf(suffix, sizeof(suffix),
- "-deleted-%" PRIu16, i);
-
- if (p_ret < 0) {
- PERROR("Failed to form suffix to rename file %s",
- inode->path);
- ret = -errno;
- goto end;
- }
- assert(p_ret != sizeof(suffix));
- } else {
- /* suffix is initialy set to '-deleted'. */
- p_ret = strlen(suffix);
- }
-
- if (original_path_len + p_ret + 1 >= sizeof(new_path)) {
- ret = -ENAMETOOLONG;
- goto end;
- }
-
- strcat(&new_path[original_path_len], suffix);
- ret = lttng_inode_rename(inode, new_path, false);
- if (ret != -EEXIST) {
- break;
- }
- new_path[original_path_len] = '\0';
- }
- if (!ret) {
- inode->unlink_pending = true;
- }
-end:
- return ret;
-}
-
-static struct lttng_inode *lttng_inode_create(const struct inode_id *id,
- const char *path,
- struct cds_lfht *ht)
-{
- struct lttng_inode *inode = zmalloc(sizeof(*inode));
-
- if (!inode) {
- goto end;
- }
-
- urcu_ref_init(&inode->ref);
- cds_lfht_node_init(&inode->registry_node);
- inode->id = *id;
- inode->path = strdup(path);
- inode->registry_ht = ht;
- if (!inode->path) {
- goto error;
- }
-end:
- return inode;
-error:
- lttng_inode_destroy(inode);
- return NULL;
-}
-
-struct lttng_inode_registry *lttng_inode_registry_create(void)
-{
- struct lttng_inode_registry *registry = zmalloc(sizeof(*registry));
-
- if (!registry) {
- goto end;
- }
-
- pthread_mutex_lock(&seed.lock);
- if (!seed.initialized) {
- seed.value = (unsigned long) time(NULL);
- seed.initialized = true;
- }
- pthread_mutex_unlock(&seed.lock);
-
- registry->inodes = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
- CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
- if (!registry->inodes) {
- goto error;
- }
-end:
- return registry;
-error:
- lttng_inode_registry_destroy(registry);
- return NULL;
-}
-
-void lttng_inode_registry_destroy(struct lttng_inode_registry *registry)
-{
- if (!registry) {
- return;
- }
- if (registry->inodes) {
- int ret = cds_lfht_destroy(registry->inodes, NULL);
-
- assert(!ret);
- }
- free(registry);
-}
-
-struct lttng_inode *lttng_inode_registry_get_inode(
- struct lttng_inode_registry *registry, int fd, const char *path)
-{
- int ret;
- struct stat statbuf;
- struct inode_id id;
- struct cds_lfht_iter iter;
- struct cds_lfht_node *node;
- struct lttng_inode *inode = NULL;
-
- ret = fstat(fd, &statbuf);
- if (ret < 0) {
- PERROR("stat() failed on file %s, fd = %i", path, fd);
- goto end;
- }
-
- id.device = statbuf.st_dev;
- id.inode = statbuf.st_ino;
-
- rcu_read_lock();
- cds_lfht_lookup(registry->inodes, lttng_inode_id_hash(&id),
- lttng_inode_match, &id, &iter);
- node = cds_lfht_iter_get_node(&iter);
- if (node) {
- inode = caa_container_of(
- node, struct lttng_inode, registry_node);
- /* Renames should happen through the fs-handle interface. */
- assert(!strcmp(path, inode->path));
- lttng_inode_get(inode);
- goto end_unlock;
- }
-
- inode = lttng_inode_create(&id, path, registry->inodes);
- node = cds_lfht_add_unique(registry->inodes,
- lttng_inode_id_hash(&inode->id), lttng_inode_match,
- &inode->id, &inode->registry_node);
- assert(node == &inode->registry_node);
-end_unlock:
- rcu_read_unlock();
-end:
- return inode;
-}
projects / lttng-tools.git / blobdiff