+++ /dev/null
-/*
- * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#include <common/defaults.h>
-#include <common/error.h>
-#include <common/hashtable/utils.h>
-#include <common/macros.h>
-#include <common/optional.h>
-#include <common/string-utils/format.h>
-#include <common/utils.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;
- /* 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;
- /* Location from which this file can be opened. */
- struct {
- struct lttng_directory_handle *directory_handle;
- char *path;
- } location;
- /* Unlink the underlying file at the release of the inode. */
- bool unlink_pending;
- LTTNG_OPTIONAL(unsigned int) unlinked_id;
- /* Weak reference. */
- struct lttng_unlinked_file_pool *unlinked_file_pool;
-};
-
-struct lttng_unlinked_file_pool {
- struct lttng_directory_handle *unlink_directory_handle;
- char *unlink_directory_path;
- unsigned int file_count;
- unsigned int next_id;
-};
-
-static struct {
- pthread_mutex_t lock;
- bool initialized;
- unsigned long value;
-} seed = {
- .lock = PTHREAD_MUTEX_INITIALIZER,
-};
-
-static unsigned long lttng_inode_id_hash(const 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;
- const 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_free(struct rcu_head *head)
-{
- struct lttng_inode *inode =
- caa_container_of(head, struct lttng_inode, rcu_head);
-
- free(inode);
-}
-
-static int lttng_unlinked_file_pool_add_inode(
- struct lttng_unlinked_file_pool *pool,
- struct lttng_inode *inode)
-{
- int ret;
- const unsigned int unlinked_id = pool->next_id++;
- char *inode_unlinked_name;
- bool reference_acquired;
-
- DBG("Adding inode of %s to unlinked file pool as id %u",
- inode->location.path, unlinked_id);
- ret = asprintf(&inode_unlinked_name, "%u", unlinked_id);
- if (ret < 0) {
- ERR("Failed to format unlinked inode name");
- ret = -1;
- goto end;
- }
-
- if (pool->file_count == 0) {
- DBG("Creating unlinked files directory at %s",
- pool->unlink_directory_path);
- LTTNG_ASSERT(!pool->unlink_directory_handle);
- ret = utils_mkdir(pool->unlink_directory_path,
- S_IRWXU | S_IRWXG, -1, -1);
- if (ret) {
- if (errno == EEXIST) {
- /*
- * Unexpected (previous crash?), but not an
- * error.
- */
- DBG("Unlinked file directory \"%s\" already exists",
- pool->unlink_directory_path);
- } else {
- PERROR("Failed to create unlinked files directory at %s",
- pool->unlink_directory_path);
- goto end;
- }
- }
- pool->unlink_directory_handle = lttng_directory_handle_create(
- pool->unlink_directory_path);
- if (!pool->unlink_directory_handle) {
- ERR("Failed to create directory handle to unlinked file pool at %s",
- pool->unlink_directory_path);
- ret = -1;
- goto end;
- }
- }
-
- ret = lttng_directory_handle_rename(inode->location.directory_handle,
- inode->location.path, pool->unlink_directory_handle,
- inode_unlinked_name);
- if (ret) {
- goto end;
- }
-
- lttng_directory_handle_put(inode->location.directory_handle);
- inode->location.directory_handle = NULL;
- reference_acquired = lttng_directory_handle_get(
- pool->unlink_directory_handle);
- LTTNG_ASSERT(reference_acquired);
- inode->location.directory_handle = pool->unlink_directory_handle;
-
- free(inode->location.path);
- inode->location.path = inode_unlinked_name;
- inode_unlinked_name = NULL;
- LTTNG_OPTIONAL_SET(&inode->unlinked_id, unlinked_id);
- pool->file_count++;
-end:
- free(inode_unlinked_name);
- return ret;
-}
-
-static int lttng_unlinked_file_pool_remove_inode(
- struct lttng_unlinked_file_pool *pool,
- struct lttng_inode *inode)
-{
- int ret;
-
- DBG("Removing inode with unlinked id %u from unlinked file pool",
- LTTNG_OPTIONAL_GET(inode->unlinked_id));
-
- ret = lttng_directory_handle_unlink_file(
- inode->location.directory_handle, inode->location.path);
- if (ret) {
- PERROR("Failed to unlink file %s from unlinked file directory",
- inode->location.path);
- goto end;
- }
- free(inode->location.path);
- inode->location.path = NULL;
- lttng_directory_handle_put(inode->location.directory_handle);
- inode->location.directory_handle = NULL;
-
- pool->file_count--;
- if (pool->file_count == 0) {
- ret = utils_recursive_rmdir(pool->unlink_directory_path);
- if (ret) {
- /*
- * There is nothing the caller can do, don't report an
- * error except through logging.
- */
- PERROR("Failed to remove unlinked files directory at %s",
- pool->unlink_directory_path);
- }
- lttng_directory_handle_put(pool->unlink_directory_handle);
- pool->unlink_directory_handle = NULL;
- }
-end:
- return ret;
-}
-
-static void lttng_inode_destroy(struct lttng_inode *inode)
-{
- if (!inode) {
- return;
- }
-
- rcu_read_lock();
- cds_lfht_del(inode->registry_ht, &inode->registry_node);
- rcu_read_unlock();
-
- if (inode->unlink_pending) {
- int ret;
-
- LTTNG_ASSERT(inode->location.directory_handle);
- LTTNG_ASSERT(inode->location.path);
- DBG("Removing %s from unlinked file pool",
- inode->location.path);
- ret = lttng_unlinked_file_pool_remove_inode(inode->unlinked_file_pool, inode);
- if (ret) {
- PERROR("Failed to unlink %s", inode->location.path);
- }
- }
-
- lttng_directory_handle_put(
- inode->location.directory_handle);
- inode->location.directory_handle = NULL;
- free(inode->location.path);
- inode->location.path = NULL;
- call_rcu(&inode->rcu_head, lttng_inode_free);
-}
-
-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);
-}
-
-struct lttng_unlinked_file_pool *lttng_unlinked_file_pool_create(
- const char *path)
-{
- struct lttng_unlinked_file_pool *pool = zmalloc(sizeof(*pool));
-
- if (!pool) {
- goto error;
- }
-
- if (!path || *path != '/') {
- ERR("Unlinked file pool must be created with an absolute path, path = \"%s\"",
- path ? path : "NULL");
- goto error;
- }
-
- pool->unlink_directory_path = strdup(path);
- if (!pool->unlink_directory_path) {
- PERROR("Failed to allocation unlinked file pool path");
- goto error;
- }
- DBG("Unlinked file pool created at: %s", path);
- return pool;
-error:
- lttng_unlinked_file_pool_destroy(pool);
- return NULL;
-}
-
-void lttng_unlinked_file_pool_destroy(
- struct lttng_unlinked_file_pool *pool)
-{
- if (!pool) {
- return;
- }
-
- LTTNG_ASSERT(pool->file_count == 0);
- lttng_directory_handle_put(pool->unlink_directory_handle);
- free(pool->unlink_directory_path);
- free(pool);
-}
-
-void lttng_inode_put(struct lttng_inode *inode)
-{
- urcu_ref_put(&inode->ref, lttng_inode_release);
-}
-
-struct lttng_directory_handle *
-lttng_inode_get_location_directory_handle(
- struct lttng_inode *inode)
-{
- if (inode->location.directory_handle) {
- const bool reference_acquired = lttng_directory_handle_get(
- inode->location.directory_handle);
-
- LTTNG_ASSERT(reference_acquired);
- }
- return inode->location.directory_handle;
-}
-
-void lttng_inode_borrow_location(struct lttng_inode *inode,
- const struct lttng_directory_handle **out_directory_handle,
- const char **out_path)
-{
- if (out_directory_handle) {
- *out_directory_handle = inode->location.directory_handle;
- }
- if (out_path) {
- *out_path = inode->location.path;
- }
-}
-
-int lttng_inode_rename(
- struct lttng_inode *inode,
- struct lttng_directory_handle *old_directory_handle,
- const char *old_path,
- struct lttng_directory_handle *new_directory_handle,
- const char *new_path,
- bool overwrite)
-{
- int ret = 0;
- char *new_path_copy = strdup(new_path);
- bool reference_acquired;
-
- DBG("Performing rename of inode from %s to %s with %s directory handles",
- old_path, new_path,
- lttng_directory_handle_equals(old_directory_handle,
- new_directory_handle) ?
- "identical" :
- "different");
-
- if (!new_path_copy) {
- ret = -ENOMEM;
- goto end;
- }
-
- if (inode->unlink_pending) {
- WARN("An attempt to rename an unlinked file from %s to %s has been performed",
- old_path, new_path);
- ret = -ENOENT;
- goto end;
- }
-
- if (!overwrite) {
- /* Verify that file doesn't exist. */
- struct stat statbuf;
-
- ret = lttng_directory_handle_stat(
- new_directory_handle, new_path, &statbuf);
- if (ret == 0) {
- ERR("Refusing to rename %s as the destination already exists",
- old_path);
- ret = -EEXIST;
- goto end;
- } else if (ret < 0 && errno != ENOENT) {
- PERROR("Failed to stat() %s", new_path);
- ret = -errno;
- goto end;
- }
- }
-
- ret = lttng_directory_handle_rename(old_directory_handle, old_path,
- new_directory_handle, new_path);
- if (ret) {
- PERROR("Failed to rename file %s to %s", old_path, new_path);
- ret = -errno;
- goto end;
- }
-
- reference_acquired = lttng_directory_handle_get(new_directory_handle);
- LTTNG_ASSERT(reference_acquired);
- lttng_directory_handle_put(inode->location.directory_handle);
- free(inode->location.path);
- inode->location.directory_handle = new_directory_handle;
- /* Ownership transferred. */
- inode->location.path = new_path_copy;
- new_path_copy = NULL;
-end:
- free(new_path_copy);
- return ret;
-}
-
-int lttng_inode_unlink(struct lttng_inode *inode)
-{
- int ret = 0;
-
- DBG("Attempting unlink of inode %s", inode->location.path);
-
- if (inode->unlink_pending) {
- WARN("An attempt to re-unlink %s has been performed, ignoring.",
- inode->location.path);
- ret = -ENOENT;
- goto end;
- }
-
- /*
- * Move to the temporary "deleted" directory until all
- * references are released.
- */
- ret = lttng_unlinked_file_pool_add_inode(
- inode->unlinked_file_pool, inode);
- if (ret) {
- PERROR("Failed to add inode \"%s\" to the unlinked file pool",
- inode->location.path);
- goto end;
- }
- inode->unlink_pending = true;
-end:
- return ret;
-}
-
-static struct lttng_inode *lttng_inode_create(const struct inode_id *id,
- struct cds_lfht *ht,
- struct lttng_unlinked_file_pool *unlinked_file_pool,
- struct lttng_directory_handle *directory_handle,
- const char *path)
-{
- struct lttng_inode *inode = NULL;
- char *path_copy;
- bool reference_acquired;
-
- path_copy = strdup(path);
- if (!path_copy) {
- goto end;
- }
-
- reference_acquired = lttng_directory_handle_get(directory_handle);
- LTTNG_ASSERT(reference_acquired);
-
- inode = zmalloc(sizeof(*inode));
- if (!inode) {
- goto end;
- }
-
- urcu_ref_init(&inode->ref);
- cds_lfht_node_init(&inode->registry_node);
- inode->id = *id;
- inode->registry_ht = ht;
- inode->unlinked_file_pool = unlinked_file_pool;
- /* Ownership of path copy is transferred to inode. */
- inode->location.path = path_copy;
- path_copy = NULL;
- inode->location.directory_handle = directory_handle;
-end:
- free(path_copy);
- return inode;
-}
-
-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);
-
- LTTNG_ASSERT(!ret);
- }
- free(registry);
-}
-
-struct lttng_inode *lttng_inode_registry_get_inode(
- struct lttng_inode_registry *registry,
- struct lttng_directory_handle *handle,
- const char *path,
- int fd,
- struct lttng_unlinked_file_pool *unlinked_file_pool)
-{
- 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 fd %i", 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);
- lttng_inode_get(inode);
- goto end_unlock;
- }
-
- inode = lttng_inode_create(&id, registry->inodes, unlinked_file_pool,
- handle, path);
- if (!inode) {
- goto end_unlock;
- }
-
- node = cds_lfht_add_unique(registry->inodes,
- lttng_inode_id_hash(&inode->id), lttng_inode_match,
- &inode->id, &inode->registry_node);
- LTTNG_ASSERT(node == &inode->registry_node);
-end_unlock:
- rcu_read_unlock();
-end:
- return inode;
-}
projects / lttng-tools.git / blobdiff