ee73a0324c75467a7cd6706a6f9efa8b13b2659f
[lttng-tools.git] / src / common / index / index.c
1 /*
2 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
3 * David Goulet <dgoulet@efficios.com>
4 * 2016 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License, version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #define _LGPL_SOURCE
21 #include <assert.h>
22 #include <sys/stat.h>
23 #include <sys/types.h>
24 #include <fcntl.h>
25
26 #include <common/common.h>
27 #include <common/defaults.h>
28 #include <common/compat/endian.h>
29 #include <common/utils.h>
30
31 #include "index.h"
32
33 /*
34 * Create the index file associated with a trace file.
35 *
36 * Return allocated struct lttng_index_file, NULL on error.
37 */
38 struct lttng_index_file *lttng_index_file_create(char *path_name,
39 char *stream_name, int uid, int gid,
40 uint64_t size, uint64_t count, uint32_t major, uint32_t minor)
41 {
42 struct lttng_index_file *index_file;
43 int ret, fd = -1;
44 ssize_t size_ret;
45 struct ctf_packet_index_file_hdr hdr;
46 char fullpath[PATH_MAX];
47 uint32_t element_len = ctf_packet_index_len(major, minor);
48
49 index_file = zmalloc(sizeof(*index_file));
50 if (!index_file) {
51 PERROR("allocating lttng_index_file");
52 goto error;
53 }
54
55 ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR,
56 path_name);
57 if (ret < 0) {
58 PERROR("snprintf index path");
59 goto error;
60 }
61
62 /* Create index directory if necessary. */
63 ret = utils_mkdir(fullpath, S_IRWXU | S_IRWXG, uid, gid);
64 if (ret < 0) {
65 if (errno != EEXIST) {
66 PERROR("Index trace directory creation error");
67 goto error;
68 }
69 }
70
71 /*
72 * For tracefile rotation. We need to unlink the old
73 * file if present to synchronize with the tail of the
74 * live viewer which could be working on this same file.
75 * By doing so, any reference to the old index file
76 * stays valid even if we re-create a new file with the
77 * same name afterwards.
78 */
79 ret = utils_unlink_stream_file(fullpath, stream_name, size, count, uid,
80 gid, DEFAULT_INDEX_FILE_SUFFIX);
81 if (ret < 0 && errno != ENOENT) {
82 goto error;
83 }
84 ret = utils_create_stream_file(fullpath, stream_name, size, count, uid,
85 gid, DEFAULT_INDEX_FILE_SUFFIX);
86 if (ret < 0) {
87 goto error;
88 }
89 fd = ret;
90
91 hdr.magic = htobe32(CTF_INDEX_MAGIC);
92 hdr.index_major = htobe32(major);
93 hdr.index_minor = htobe32(minor);
94 hdr.packet_index_len = htobe32(element_len);
95
96 size_ret = lttng_write(fd, &hdr, sizeof(hdr));
97 if (size_ret < sizeof(hdr)) {
98 PERROR("write index header");
99 ret = -1;
100 goto error;
101 }
102 index_file->fd = fd;
103 index_file->major = major;
104 index_file->minor = minor;
105 index_file->element_len = element_len;
106 urcu_ref_init(&index_file->ref);
107
108 return index_file;
109
110 error:
111 if (fd >= 0) {
112 int close_ret;
113
114 close_ret = close(fd);
115 if (close_ret < 0) {
116 PERROR("close index fd");
117 }
118 }
119 free(index_file);
120 return NULL;
121 }
122
123 /*
124 * Write index values to the given index file.
125 *
126 * Return 0 on success, -1 on error.
127 */
128 int lttng_index_file_write(const struct lttng_index_file *index_file,
129 const struct ctf_packet_index *element)
130 {
131 int fd;
132 size_t len;
133 ssize_t ret;
134
135 assert(index_file);
136 assert(element);
137
138 fd = index_file->fd;
139 len = index_file->element_len;
140
141 if (fd < 0) {
142 goto error;
143 }
144
145 ret = lttng_write(fd, element, len);
146 if (ret < len) {
147 PERROR("writing index file");
148 goto error;
149 }
150 return 0;
151
152 error:
153 return -1;
154 }
155
156 /*
157 * Read index values from the given index file.
158 *
159 * Return 0 on success, -1 on error.
160 */
161 int lttng_index_file_read(const struct lttng_index_file *index_file,
162 struct ctf_packet_index *element)
163 {
164 ssize_t ret;
165 int fd = index_file->fd;
166 size_t len = index_file->element_len;
167
168 assert(element);
169
170 if (fd < 0) {
171 goto error;
172 }
173
174 ret = lttng_read(fd, element, len);
175 if (ret < len) {
176 PERROR("read index file");
177 goto error;
178 }
179 return 0;
180
181 error:
182 return -1;
183 }
184
185 /*
186 * Open index file using a given path, channel name and tracefile count.
187 *
188 * Return allocated struct lttng_index_file, NULL on error.
189 */
190 struct lttng_index_file *lttng_index_file_open(const char *path_name,
191 const char *channel_name, uint64_t tracefile_count,
192 uint64_t tracefile_count_current)
193 {
194 struct lttng_index_file *index_file;
195 int ret, read_fd;
196 ssize_t read_len;
197 char fullpath[PATH_MAX];
198 struct ctf_packet_index_file_hdr hdr;
199 uint32_t major, minor, element_len;
200
201 assert(path_name);
202 assert(channel_name);
203
204 index_file = zmalloc(sizeof(*index_file));
205 if (!index_file) {
206 PERROR("allocating lttng_index_file");
207 goto error;
208 }
209
210 if (tracefile_count > 0) {
211 ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s_%"
212 PRIu64 DEFAULT_INDEX_FILE_SUFFIX, path_name,
213 channel_name, tracefile_count_current);
214 } else {
215 ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s"
216 DEFAULT_INDEX_FILE_SUFFIX, path_name, channel_name);
217 }
218 if (ret < 0) {
219 PERROR("snprintf index path");
220 goto error;
221 }
222
223 DBG("Index opening file %s in read only", fullpath);
224 read_fd = open(fullpath, O_RDONLY);
225 if (read_fd < 0) {
226 PERROR("opening index in read-only");
227 goto error;
228 }
229
230 read_len = lttng_read(read_fd, &hdr, sizeof(hdr));
231 if (read_len < 0) {
232 PERROR("Reading index header");
233 goto error_close;
234 }
235
236 if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) {
237 ERR("Invalid header magic");
238 goto error_close;
239 }
240 major = be32toh(hdr.index_major);
241 minor = be32toh(hdr.index_minor);
242 element_len = be32toh(hdr.packet_index_len);
243
244 if (major != CTF_INDEX_MAJOR) {
245 ERR("Invalid header version");
246 goto error_close;
247 }
248 if (element_len > sizeof(struct ctf_packet_index)) {
249 ERR("Index element length too long");
250 goto error_close;
251 }
252
253 index_file->fd = read_fd;
254 index_file->major = major;
255 index_file->minor = minor;
256 index_file->element_len = element_len;
257 urcu_ref_init(&index_file->ref);
258
259 return index_file;
260
261 error_close:
262 if (read_fd >= 0) {
263 int close_ret;
264
265 close_ret = close(read_fd);
266 if (close_ret < 0) {
267 PERROR("close read fd %d", read_fd);
268 }
269 }
270
271 error:
272 free(index_file);
273 return NULL;
274 }
275
276 void lttng_index_file_get(struct lttng_index_file *index_file)
277 {
278 urcu_ref_get(&index_file->ref);
279 }
280
281 static void lttng_index_file_release(struct urcu_ref *ref)
282 {
283 struct lttng_index_file *index_file = caa_container_of(ref,
284 struct lttng_index_file, ref);
285
286 if (close(index_file->fd)) {
287 PERROR("close index fd");
288 }
289 free(index_file);
290 }
291
292 void lttng_index_file_put(struct lttng_index_file *index_file)
293 {
294 urcu_ref_put(&index_file->ref, lttng_index_file_release);
295 }
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