| 1 | /* |
| 2 | * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com> |
| 3 | * David Goulet <dgoulet@efficios.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License, version 2 only, as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along with |
| 15 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 16 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <assert.h> |
| 21 | |
| 22 | #include <common/common.h> |
| 23 | #include <common/utils.h> |
| 24 | |
| 25 | #include "lttng-relayd.h" |
| 26 | #include "index.h" |
| 27 | |
| 28 | /* |
| 29 | * Deferred free of a relay index object. MUST only be called by a call RCU. |
| 30 | */ |
| 31 | static void deferred_free_relay_index(struct rcu_head *head) |
| 32 | { |
| 33 | struct relay_index *index = |
| 34 | caa_container_of(head, struct relay_index, rcu_node); |
| 35 | |
| 36 | if (index->to_close_fd >= 0) { |
| 37 | int ret; |
| 38 | |
| 39 | ret = close(index->to_close_fd); |
| 40 | if (ret < 0) { |
| 41 | PERROR("Relay index to close fd %d", index->to_close_fd); |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | relay_index_free(index); |
| 46 | } |
| 47 | |
| 48 | /* |
| 49 | * Allocate a new relay index object using the given stream ID and sequence |
| 50 | * number as the hash table key. |
| 51 | * |
| 52 | * Return allocated object or else NULL on error. |
| 53 | */ |
| 54 | struct relay_index *relay_index_create(uint64_t stream_id, |
| 55 | uint64_t net_seq_num) |
| 56 | { |
| 57 | struct relay_index *index; |
| 58 | |
| 59 | DBG2("Creating relay index with stream id %" PRIu64 " and seqnum %" PRIu64, |
| 60 | stream_id, net_seq_num); |
| 61 | |
| 62 | index = zmalloc(sizeof(*index)); |
| 63 | if (index == NULL) { |
| 64 | PERROR("Relay index zmalloc"); |
| 65 | goto error; |
| 66 | } |
| 67 | |
| 68 | index->to_close_fd = -1; |
| 69 | lttng_ht_node_init_two_u64(&index->index_n, stream_id, net_seq_num); |
| 70 | |
| 71 | error: |
| 72 | return index; |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * Find a relayd index in the given hash table. |
| 77 | * |
| 78 | * Return index object or else NULL on error. |
| 79 | */ |
| 80 | struct relay_index *relay_index_find(uint64_t stream_id, uint64_t net_seq_num) |
| 81 | { |
| 82 | struct lttng_ht_node_two_u64 *node; |
| 83 | struct lttng_ht_iter iter; |
| 84 | struct lttng_ht_two_u64 key; |
| 85 | struct relay_index *index = NULL; |
| 86 | |
| 87 | DBG3("Finding index for stream id %" PRIu64 " and seq_num %" PRIu64, |
| 88 | stream_id, net_seq_num); |
| 89 | |
| 90 | key.key1 = stream_id; |
| 91 | key.key2 = net_seq_num; |
| 92 | |
| 93 | lttng_ht_lookup(indexes_ht, (void *)(&key), &iter); |
| 94 | node = lttng_ht_iter_get_node_two_u64(&iter); |
| 95 | if (node == NULL) { |
| 96 | goto end; |
| 97 | } |
| 98 | index = caa_container_of(node, struct relay_index, index_n); |
| 99 | |
| 100 | end: |
| 101 | DBG2("Index %sfound in HT for stream ID %" PRIu64 " and seqnum %" PRIu64, |
| 102 | (index == NULL) ? "NOT " : "", stream_id, net_seq_num); |
| 103 | return index; |
| 104 | } |
| 105 | |
| 106 | /* |
| 107 | * Add unique relay index to the given hash table. In case of a collision, the |
| 108 | * already existing object is put in the given _index variable. |
| 109 | * |
| 110 | * RCU read side lock MUST be acquired. |
| 111 | */ |
| 112 | void relay_index_add(struct relay_index *index, struct relay_index **_index) |
| 113 | { |
| 114 | struct cds_lfht_node *node_ptr; |
| 115 | |
| 116 | assert(index); |
| 117 | |
| 118 | DBG2("Adding relay index with stream id %" PRIu64 " and seqnum %" PRIu64, |
| 119 | index->key.key1, index->key.key2); |
| 120 | |
| 121 | node_ptr = cds_lfht_add_unique(indexes_ht->ht, |
| 122 | indexes_ht->hash_fct((void *) &index->index_n.key, lttng_ht_seed), |
| 123 | indexes_ht->match_fct, (void *) &index->index_n.key, |
| 124 | &index->index_n.node); |
| 125 | if (node_ptr != &index->index_n.node) { |
| 126 | *_index = caa_container_of(node_ptr, struct relay_index, index_n.node); |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * Write index on disk to the given fd. Once done error or not, it is removed |
| 132 | * from the hash table and destroy the object. |
| 133 | * |
| 134 | * MUST be called with a RCU read side lock held. |
| 135 | * |
| 136 | * Return 0 on success else a negative value. |
| 137 | */ |
| 138 | int relay_index_write(int fd, struct relay_index *index) |
| 139 | { |
| 140 | int ret; |
| 141 | struct lttng_ht_iter iter; |
| 142 | |
| 143 | DBG2("Writing index for stream ID %" PRIu64 " and seq num %" PRIu64 |
| 144 | " on fd %d", index->key.key1, index->key.key2, fd); |
| 145 | |
| 146 | /* Delete index from hash table. */ |
| 147 | iter.iter.node = &index->index_n.node; |
| 148 | ret = lttng_ht_del(indexes_ht, &iter); |
| 149 | assert(!ret); |
| 150 | call_rcu(&index->rcu_node, deferred_free_relay_index); |
| 151 | |
| 152 | return index_write(fd, &index->index_data, sizeof(index->index_data)); |
| 153 | } |
| 154 | |
| 155 | /* |
| 156 | * Free the given index. |
| 157 | */ |
| 158 | void relay_index_free(struct relay_index *index) |
| 159 | { |
| 160 | free(index); |
| 161 | } |
| 162 | |
| 163 | /* |
| 164 | * Safely free the given index using a call RCU. |
| 165 | */ |
| 166 | void relay_index_free_safe(struct relay_index *index) |
| 167 | { |
| 168 | if (!index) { |
| 169 | return; |
| 170 | } |
| 171 | |
| 172 | call_rcu(&index->rcu_node, deferred_free_relay_index); |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Delete index from the given hash table. |
| 177 | * |
| 178 | * RCU read side lock MUST be acquired. |
| 179 | */ |
| 180 | void relay_index_delete(struct relay_index *index) |
| 181 | { |
| 182 | int ret; |
| 183 | struct lttng_ht_iter iter; |
| 184 | |
| 185 | DBG3("Relay index with stream ID %" PRIu64 " and seq num %" PRIu64 |
| 186 | "deleted.", index->key.key1, index->key.key2); |
| 187 | |
| 188 | /* Delete index from hash table. */ |
| 189 | iter.iter.node = &index->index_n.node; |
| 190 | ret = lttng_ht_del(indexes_ht, &iter); |
| 191 | assert(!ret); |
| 192 | } |
| 193 | |
| 194 | /* |
| 195 | * Destroy every relay index with the given stream id as part of the key. |
| 196 | */ |
| 197 | void relay_index_destroy_by_stream_id(uint64_t stream_id) |
| 198 | { |
| 199 | struct lttng_ht_iter iter; |
| 200 | struct relay_index *index; |
| 201 | |
| 202 | rcu_read_lock(); |
| 203 | cds_lfht_for_each_entry(indexes_ht->ht, &iter.iter, index, index_n.node) { |
| 204 | if (index->key.key1 == stream_id) { |
| 205 | relay_index_delete(index); |
| 206 | relay_index_free_safe(index); |
| 207 | } |
| 208 | } |
| 209 | rcu_read_unlock(); |
| 210 | } |