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2b508613 JG |
1 | /* |
2 | * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License, version 2 only, as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
16 | */ | |
17 | ||
18 | #include "index-file.h" | |
19 | #include "lttng-relayd.h" | |
20 | ||
21 | #include <common/defaults.h> | |
22 | #include <common/error.h> | |
23 | #include <common/utils.h> | |
24 | #include <common/readwrite.h> | |
25 | #include <common/fd-tracker/fd-tracker.h> | |
26 | #include <common/fd-tracker/utils.h> | |
27 | #include <lttng/constant.h> | |
28 | ||
29 | #include <inttypes.h> | |
30 | #include <stdbool.h> | |
31 | #include <urcu/ref.h> | |
32 | #include <sys/stat.h> | |
33 | #include <fcntl.h> | |
34 | ||
35 | struct relay_index_file { | |
bd744515 | 36 | struct fs_handle *handle; |
2b508613 JG |
37 | uint32_t major; |
38 | uint32_t minor; | |
39 | uint32_t element_len; | |
40 | struct urcu_ref ref; | |
41 | }; | |
42 | ||
bd744515 JG |
43 | /* |
44 | * This unlink wrapper allows the fd_tracker to check if any other | |
45 | * fs_handle references the index before unlinking it. If the relay holds | |
46 | * this file open, it is essential to unlink it through an fs_handle as this | |
47 | * will delay the actual unlink() until all handles have released this file. | |
48 | * | |
49 | * The file is renamed and unlinked once the last handle to its inode has been | |
50 | * released. | |
51 | */ | |
52 | static | |
53 | int unlink_through_handle(const char *path) | |
54 | { | |
55 | int ret = 0, close_ret; | |
56 | struct fs_handle *handle; | |
57 | /* | |
58 | * Since this operation is only performed to perform the unlink | |
59 | * through the fs_handle and fd-tracker system, the flag is opened | |
60 | * without the O_CREAT. There is no need to perform the unlink if | |
61 | * the file doesn't already exist. | |
62 | */ | |
63 | int flags = O_RDONLY; | |
64 | ||
65 | DBG("Unlinking index at %s through a filesystem handle", path); | |
66 | handle = fd_tracker_open_fs_handle(the_fd_tracker, path, flags, NULL); | |
67 | if (!handle) { | |
68 | /* There is nothing to do. */ | |
69 | DBG("File %s does not exist, ignoring unlink", path); | |
70 | goto end; | |
71 | } | |
72 | ||
73 | ret = fs_handle_unlink(handle); | |
74 | close_ret = fs_handle_close(handle); | |
75 | if (close_ret) { | |
76 | ERR("Failed to close handle after performing an unlink operation on a filesystem handle"); | |
77 | } | |
78 | end: | |
79 | if (ret) { | |
80 | DBG("Unlinking index at %s failed with error code %i", path, ret); | |
81 | } | |
82 | return ret; | |
83 | } | |
84 | ||
2b508613 JG |
85 | /* |
86 | * Create the index file associated with a trace file. | |
87 | * | |
88 | * Return allocated struct lttng_index_file, NULL on error. | |
89 | */ | |
90 | struct relay_index_file *relay_index_file_create(const char *path_name, | |
91 | const char *stream_name, uint64_t size, uint64_t count, | |
92 | uint32_t idx_major, uint32_t idx_minor) | |
93 | { | |
94 | struct relay_index_file *index_file; | |
95 | struct fs_handle *fs_handle = NULL; | |
96 | int ret, fd = -1; | |
97 | ssize_t size_ret; | |
98 | struct ctf_packet_index_file_hdr hdr; | |
99 | char idx_dir_path[LTTNG_PATH_MAX]; | |
100 | char idx_file_path[LTTNG_PATH_MAX]; | |
101 | /* | |
102 | * With the session rotation feature on the relay, we might need to seek | |
103 | * and truncate a tracefile, so we need read and write access. | |
104 | */ | |
105 | int flags = O_RDWR | O_CREAT | O_TRUNC; | |
106 | /* Open with 660 mode */ | |
107 | mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP; | |
108 | ||
109 | index_file = zmalloc(sizeof(*index_file)); | |
110 | if (!index_file) { | |
111 | PERROR("allocating relay_index_file"); | |
112 | goto error; | |
113 | } | |
114 | ||
2b508613 JG |
115 | ret = snprintf(idx_dir_path, sizeof(idx_dir_path), "%s/" DEFAULT_INDEX_DIR, |
116 | path_name); | |
117 | if (ret < 0) { | |
118 | PERROR("snprintf index path"); | |
119 | goto error; | |
120 | } | |
121 | ||
122 | /* Create index directory if necessary. */ | |
123 | ret = utils_mkdir(idx_dir_path, S_IRWXU | S_IRWXG, -1, -1); | |
124 | if (ret < 0) { | |
125 | if (errno != EEXIST) { | |
126 | PERROR("Index trace directory creation error"); | |
127 | goto error; | |
128 | } | |
129 | } | |
130 | ||
131 | ret = utils_stream_file_name(idx_file_path, idx_dir_path, stream_name, | |
132 | size, count, DEFAULT_INDEX_FILE_SUFFIX); | |
133 | if (ret < 0) { | |
134 | ERR("Could not build path of index file"); | |
135 | goto error; | |
136 | } | |
137 | ||
138 | /* | |
139 | * For tracefile rotation. We need to unlink the old | |
140 | * file if present to synchronize with the tail of the | |
141 | * live viewer which could be working on this same file. | |
142 | * By doing so, any reference to the old index file | |
143 | * stays valid even if we re-create a new file with the | |
144 | * same name afterwards. | |
145 | */ | |
bd744515 JG |
146 | ret = unlink_through_handle(idx_file_path); |
147 | if (ret < 0) { | |
2b508613 JG |
148 | goto error; |
149 | } | |
150 | ||
151 | fs_handle = fd_tracker_open_fs_handle(the_fd_tracker, idx_file_path, | |
152 | flags, &mode); | |
153 | if (!fs_handle) { | |
154 | goto error; | |
155 | } | |
bd744515 | 156 | index_file->handle = fs_handle; |
2b508613 JG |
157 | |
158 | fd = fs_handle_get_fd(fs_handle); | |
159 | if (fd < 0) { | |
160 | goto error; | |
161 | } | |
162 | ||
163 | ctf_packet_index_file_hdr_init(&hdr, idx_major, idx_minor); | |
164 | size_ret = lttng_write(fd, &hdr, sizeof(hdr)); | |
165 | if (size_ret < sizeof(hdr)) { | |
166 | PERROR("write index header"); | |
167 | goto error; | |
168 | } | |
169 | ||
170 | index_file->major = idx_major; | |
171 | index_file->minor = idx_minor; | |
172 | index_file->element_len = ctf_packet_index_len(idx_major, idx_minor); | |
173 | urcu_ref_init(&index_file->ref); | |
174 | ||
175 | fs_handle_put_fd(fs_handle); | |
176 | ||
177 | return index_file; | |
178 | ||
179 | error: | |
180 | if (fd >= 0) { | |
181 | fs_handle_put_fd(fs_handle); | |
182 | } | |
183 | if (fs_handle) { | |
184 | int close_ret; | |
185 | ||
186 | close_ret = fs_handle_close(fs_handle); | |
187 | if (close_ret < 0) { | |
188 | PERROR("Failed to close index filesystem handle"); | |
189 | } | |
190 | } | |
191 | free(index_file); | |
192 | return NULL; | |
193 | } | |
194 | ||
2b508613 JG |
195 | struct relay_index_file *relay_index_file_open(const char *path_name, |
196 | const char *channel_name, uint64_t tracefile_count, | |
197 | uint64_t tracefile_count_current) | |
198 | { | |
199 | struct relay_index_file *index_file; | |
bd744515 | 200 | int ret, fd = -1; |
2b508613 JG |
201 | ssize_t read_len; |
202 | char fullpath[PATH_MAX]; | |
2b508613 JG |
203 | struct ctf_packet_index_file_hdr hdr; |
204 | uint32_t major, minor, element_len; | |
bd744515 JG |
205 | int flags = O_RDONLY; |
206 | struct fs_handle *handle = NULL; | |
2b508613 JG |
207 | |
208 | assert(path_name); | |
209 | assert(channel_name); | |
210 | ||
211 | index_file = zmalloc(sizeof(*index_file)); | |
212 | if (!index_file) { | |
213 | PERROR("Failed to allocate relay_index_file"); | |
214 | goto error; | |
215 | } | |
216 | ||
2b508613 JG |
217 | if (tracefile_count > 0) { |
218 | ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s_%" | |
219 | PRIu64 DEFAULT_INDEX_FILE_SUFFIX, path_name, | |
220 | channel_name, tracefile_count_current); | |
221 | } else { | |
222 | ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s" | |
223 | DEFAULT_INDEX_FILE_SUFFIX, path_name, channel_name); | |
224 | } | |
225 | if (ret < 0) { | |
226 | PERROR("Failed to build index path"); | |
227 | goto error; | |
228 | } | |
229 | ||
bd744515 JG |
230 | DBG("Index opening file %s in read only mode", fullpath); |
231 | handle = fd_tracker_open_fs_handle(the_fd_tracker, fullpath, flags, | |
232 | NULL); | |
233 | if (!handle) { | |
2b508613 JG |
234 | PERROR("Failed to open index file at %s", fullpath); |
235 | goto error; | |
236 | } | |
237 | ||
bd744515 JG |
238 | fd = fs_handle_get_fd(handle); |
239 | if (fd < 0) { | |
240 | PERROR("Failed to get fd of index file at %s", fullpath); | |
241 | goto error; | |
242 | } | |
243 | ||
2b508613 JG |
244 | read_len = lttng_read(fd, &hdr, sizeof(hdr)); |
245 | if (read_len < 0) { | |
246 | PERROR("Failed to read index header"); | |
247 | goto error_close; | |
248 | } | |
249 | ||
250 | if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) { | |
251 | ERR("Invalid header magic %#010x, expected %#010x", | |
252 | be32toh(hdr.magic), CTF_INDEX_MAGIC); | |
253 | goto error_close; | |
254 | } | |
255 | major = be32toh(hdr.index_major); | |
256 | minor = be32toh(hdr.index_minor); | |
257 | element_len = be32toh(hdr.packet_index_len); | |
258 | ||
259 | if (major != CTF_INDEX_MAJOR) { | |
260 | ERR("Invalid header version, major = %" PRIu32 ", expected %i", | |
261 | major, CTF_INDEX_MAJOR); | |
262 | goto error_close; | |
263 | } | |
264 | if (element_len > sizeof(struct ctf_packet_index)) { | |
265 | ERR("Index element length too long (%" PRIu32 " bytes)", | |
266 | element_len); | |
267 | goto error_close; | |
268 | } | |
269 | ||
bd744515 JG |
270 | fs_handle_put_fd(handle); |
271 | index_file->handle = handle; | |
2b508613 JG |
272 | index_file->major = major; |
273 | index_file->minor = minor; | |
274 | index_file->element_len = element_len; | |
275 | urcu_ref_init(&index_file->ref); | |
276 | ||
277 | return index_file; | |
278 | ||
279 | error_close: | |
bd744515 JG |
280 | if (fd >= 0) { |
281 | fs_handle_put_fd(handle); | |
282 | } | |
283 | ret = fs_handle_close(handle); | |
2b508613 | 284 | if (ret < 0) { |
bd744515 JG |
285 | PERROR("Failed to close index filesystem handle to %s", |
286 | fullpath); | |
2b508613 JG |
287 | } |
288 | ||
289 | error: | |
290 | free(index_file); | |
291 | return NULL; | |
292 | } | |
293 | ||
294 | int relay_index_file_write(const struct relay_index_file *index_file, | |
295 | const struct ctf_packet_index *element) | |
296 | { | |
297 | int fd, ret; | |
298 | ssize_t write_ret; | |
299 | ||
300 | assert(index_file); | |
301 | assert(element); | |
302 | ||
bd744515 | 303 | fd = fs_handle_get_fd(index_file->handle); |
2b508613 JG |
304 | if (fd < 0) { |
305 | ret = fd; | |
306 | goto end; | |
307 | } | |
308 | ||
309 | write_ret = lttng_write(fd, element, index_file->element_len); | |
310 | if (write_ret < index_file->element_len) { | |
311 | PERROR("Failed to write packet index to index file"); | |
312 | ret = -1; | |
313 | } | |
314 | ret = 0; | |
315 | ||
bd744515 | 316 | fs_handle_put_fd(index_file->handle); |
2b508613 JG |
317 | end: |
318 | return ret; | |
319 | } | |
320 | ||
321 | int relay_index_file_read(const struct relay_index_file *index_file, | |
322 | struct ctf_packet_index *element) | |
323 | { | |
324 | int fd, ret; | |
325 | ssize_t read_ret; | |
326 | ||
327 | assert(index_file); | |
328 | assert(element); | |
329 | ||
bd744515 | 330 | fd = fs_handle_get_fd(index_file->handle); |
2b508613 JG |
331 | if (fd < 0) { |
332 | ret = fd; | |
333 | goto end; | |
334 | } | |
335 | ||
336 | read_ret = lttng_read(fd, element, index_file->element_len); | |
337 | if (read_ret < index_file->element_len) { | |
338 | PERROR("Failed to read packet index from file"); | |
339 | ret = -1; | |
340 | } | |
341 | ret = 0; | |
342 | ||
bd744515 | 343 | fs_handle_put_fd(index_file->handle); |
2b508613 JG |
344 | end: |
345 | return ret; | |
346 | } | |
347 | ||
348 | int relay_index_file_seek_end(struct relay_index_file *index_file) | |
349 | { | |
350 | int fd, ret = 0; | |
351 | off_t lseek_ret; | |
352 | ||
bd744515 | 353 | fd = fs_handle_get_fd(index_file->handle); |
2b508613 JG |
354 | if (fd < 0) { |
355 | ret = fd; | |
356 | goto end; | |
357 | } | |
358 | ||
359 | lseek_ret = lseek(fd, 0, SEEK_END); | |
360 | if (lseek_ret < 0) { | |
361 | ret = lseek_ret; | |
362 | } | |
363 | ||
bd744515 | 364 | fs_handle_put_fd(index_file->handle); |
2b508613 JG |
365 | end: |
366 | return ret; | |
367 | } | |
368 | ||
369 | void relay_index_file_get(struct relay_index_file *index_file) | |
370 | { | |
371 | urcu_ref_get(&index_file->ref); | |
372 | } | |
373 | ||
374 | static | |
375 | void relay_index_file_release(struct urcu_ref *ref) | |
376 | { | |
377 | int ret; | |
378 | struct relay_index_file *index_file = caa_container_of(ref, | |
379 | struct relay_index_file, ref); | |
380 | ||
bd744515 | 381 | ret = fs_handle_close(index_file->handle); |
2b508613 JG |
382 | if (ret < 0) { |
383 | PERROR("Failed to close index file"); | |
384 | } | |
385 | free(index_file); | |
386 | } | |
387 | ||
388 | void relay_index_file_put(struct relay_index_file *index_file) | |
389 | { | |
390 | urcu_ref_put(&index_file->ref, relay_index_file_release); | |
391 | } |