9f7e5f67a18dd4e8d67827890730695ec41bd2e2
[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 <lttng/constant.h>
27 #include <common/common.h>
28 #include <common/defaults.h>
29 #include <common/compat/endian.h>
30 #include <common/utils.h>
31
32 #include "index.h"
33
34 #define WRITE_FILE_FLAGS (O_WRONLY | O_CREAT | O_TRUNC)
35 #define READ_ONLY_FILE_FLAGS O_RDONLY
36
37 static enum lttng_trace_chunk_status _lttng_index_file_create_from_trace_chunk(
38 struct lttng_trace_chunk *chunk,
39 const char *channel_path, const char *stream_name,
40 uint64_t stream_file_size, uint64_t stream_file_index,
41 uint32_t index_major, uint32_t index_minor,
42 bool unlink_existing_file,
43 int flags, bool expect_no_file, struct lttng_index_file **file)
44 {
45 struct lttng_index_file *index_file;
46 enum lttng_trace_chunk_status chunk_status;
47 int ret, fd = -1;
48 ssize_t size_ret;
49 struct ctf_packet_index_file_hdr hdr;
50 char index_directory_path[LTTNG_PATH_MAX];
51 char index_file_path[LTTNG_PATH_MAX];
52 const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
53 const bool acquired_reference = lttng_trace_chunk_get(chunk);
54 const char *separator;
55
56 assert(acquired_reference);
57
58 index_file = zmalloc(sizeof(*index_file));
59 if (!index_file) {
60 PERROR("Failed to allocate lttng_index_file");
61 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
62 goto error;
63 }
64
65 index_file->trace_chunk = chunk;
66 if (channel_path[0] == '\0') {
67 separator = "";
68 } else {
69 separator = "/";
70 }
71 ret = snprintf(index_directory_path, sizeof(index_directory_path),
72 "%s%s" DEFAULT_INDEX_DIR, channel_path, separator);
73 if (ret < 0 || ret >= sizeof(index_directory_path)) {
74 ERR("Failed to format index directory path");
75 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
76 goto error;
77 }
78
79 ret = utils_stream_file_path(index_directory_path, stream_name,
80 stream_file_size, stream_file_index,
81 DEFAULT_INDEX_FILE_SUFFIX,
82 index_file_path, sizeof(index_file_path));
83 if (ret) {
84 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
85 goto error;
86 }
87
88 if (unlink_existing_file) {
89 /*
90 * For tracefile rotation. We need to unlink the old
91 * file if present to synchronize with the tail of the
92 * live viewer which could be working on this same file.
93 * By doing so, any reference to the old index file
94 * stays valid even if we re-create a new file with the
95 * same name afterwards.
96 */
97 chunk_status = lttng_trace_chunk_unlink_file(
98 chunk, index_file_path);
99 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK &&
100 !(chunk_status == LTTNG_TRACE_CHUNK_STATUS_ERROR &&
101 errno == ENOENT)) {
102 goto error;
103 }
104 }
105
106 chunk_status = lttng_trace_chunk_open_file(chunk, index_file_path,
107 flags, mode, &fd, expect_no_file);
108 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
109 goto error;
110 }
111
112 if (flags == WRITE_FILE_FLAGS) {
113 ctf_packet_index_file_hdr_init(&hdr, index_major, index_minor);
114 size_ret = lttng_write(fd, &hdr, sizeof(hdr));
115 if (size_ret < sizeof(hdr)) {
116 PERROR("Failed to write index header");
117 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
118 goto error;
119 }
120 index_file->element_len = ctf_packet_index_len(index_major, index_minor);
121 } else {
122 uint32_t element_len;
123
124 size_ret = lttng_read(fd, &hdr, sizeof(hdr));
125 if (size_ret < 0) {
126 PERROR("Failed to read index header");
127 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
128 goto error;
129 }
130 if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) {
131 ERR("Invalid header magic");
132 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
133 goto error;
134 }
135 if (index_major != be32toh(hdr.index_major)) {
136 ERR("Index major number mismatch: %u, expect %u",
137 be32toh(hdr.index_major), index_major);
138 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
139 goto error;
140 }
141 if (index_minor != be32toh(hdr.index_minor)) {
142 ERR("Index minor number mismatch: %u, expect %u",
143 be32toh(hdr.index_minor), index_minor);
144 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
145 goto error;
146 }
147 element_len = be32toh(hdr.packet_index_len);
148 if (element_len > sizeof(struct ctf_packet_index)) {
149 ERR("Index element length too long");
150 chunk_status = LTTNG_TRACE_CHUNK_STATUS_ERROR;
151 goto error;
152 }
153 index_file->element_len = element_len;
154 }
155 index_file->fd = fd;
156 index_file->major = index_major;
157 index_file->minor = index_minor;
158 urcu_ref_init(&index_file->ref);
159
160 *file = index_file;
161 return LTTNG_TRACE_CHUNK_STATUS_OK;
162
163 error:
164 if (fd >= 0) {
165 ret = close(fd);
166 if (ret < 0) {
167 PERROR("Failed to close file descriptor of index file");
168 }
169 }
170 lttng_trace_chunk_put(chunk);
171 free(index_file);
172 return chunk_status;
173 }
174
175 enum lttng_trace_chunk_status lttng_index_file_create_from_trace_chunk(
176 struct lttng_trace_chunk *chunk,
177 const char *channel_path, const char *stream_name,
178 uint64_t stream_file_size, uint64_t stream_file_index,
179 uint32_t index_major, uint32_t index_minor,
180 bool unlink_existing_file, struct lttng_index_file **file)
181 {
182 return _lttng_index_file_create_from_trace_chunk(chunk, channel_path,
183 stream_name, stream_file_size, stream_file_index,
184 index_major, index_minor, unlink_existing_file,
185 WRITE_FILE_FLAGS, false, file);
186 }
187
188 enum lttng_trace_chunk_status lttng_index_file_create_from_trace_chunk_read_only(
189 struct lttng_trace_chunk *chunk,
190 const char *channel_path, const char *stream_name,
191 uint64_t stream_file_size, uint64_t stream_file_index,
192 uint32_t index_major, uint32_t index_minor,
193 bool expect_no_file, struct lttng_index_file **file)
194 {
195 return _lttng_index_file_create_from_trace_chunk(chunk, channel_path,
196 stream_name, stream_file_size, stream_file_index,
197 index_major, index_minor, false,
198 READ_ONLY_FILE_FLAGS, expect_no_file, file);
199 }
200
201 /*
202 * Write index values to the given index file.
203 *
204 * Return 0 on success, -1 on error.
205 */
206 int lttng_index_file_write(const struct lttng_index_file *index_file,
207 const struct ctf_packet_index *element)
208 {
209 int fd;
210 size_t len;
211 ssize_t ret;
212
213 assert(index_file);
214 assert(element);
215
216 fd = index_file->fd;
217 len = index_file->element_len;
218
219 if (fd < 0) {
220 goto error;
221 }
222
223 ret = lttng_write(fd, element, len);
224 if (ret < len) {
225 PERROR("writing index file");
226 goto error;
227 }
228 return 0;
229
230 error:
231 return -1;
232 }
233
234 /*
235 * Read index values from the given index file.
236 *
237 * Return 0 on success, -1 on error.
238 */
239 int lttng_index_file_read(const struct lttng_index_file *index_file,
240 struct ctf_packet_index *element)
241 {
242 ssize_t ret;
243 int fd = index_file->fd;
244 size_t len = index_file->element_len;
245
246 assert(element);
247
248 if (fd < 0) {
249 goto error;
250 }
251
252 ret = lttng_read(fd, element, len);
253 if (ret < 0) {
254 PERROR("read index file");
255 goto error;
256 }
257 if (ret < len) {
258 ERR("lttng_read expected %zu, returned %zd", len, ret);
259 goto error;
260 }
261 return 0;
262
263 error:
264 return -1;
265 }
266
267 void lttng_index_file_get(struct lttng_index_file *index_file)
268 {
269 urcu_ref_get(&index_file->ref);
270 }
271
272 static void lttng_index_file_release(struct urcu_ref *ref)
273 {
274 struct lttng_index_file *index_file = caa_container_of(ref,
275 struct lttng_index_file, ref);
276
277 if (close(index_file->fd)) {
278 PERROR("close index fd");
279 }
280 lttng_trace_chunk_put(index_file->trace_chunk);
281 free(index_file);
282 }
283
284 void lttng_index_file_put(struct lttng_index_file *index_file)
285 {
286 urcu_ref_put(&index_file->ref, lttng_index_file_release);
287 }
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