46f8bcb1f02bfcb185782d65bb5e77fa8c4720cc
[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 *
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 #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 fd on success, a negative value on error.
37 */
38 int index_create_file(char *path_name, char *stream_name, int uid, int gid,
39 uint64_t size, uint64_t count)
40 {
41 int ret, fd = -1;
42 ssize_t size_ret;
43 struct ctf_packet_index_file_hdr hdr;
44 char fullpath[PATH_MAX];
45
46 ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR,
47 path_name);
48 if (ret < 0) {
49 PERROR("snprintf index path");
50 goto error;
51 }
52
53 /* Create index directory if necessary. */
54 ret = utils_mkdir(fullpath, S_IRWXU | S_IRWXG, uid, gid);
55 if (ret < 0) {
56 if (ret != -EEXIST) {
57 PERROR("Index trace directory creation error");
58 goto error;
59 }
60 }
61
62 /*
63 * For tracefile rotation. We need to unlink the old
64 * file if present to synchronize with the tail of the
65 * live viewer which could be working on this same file.
66 * By doing so, any reference to the old index file
67 * stays valid even if we re-create a new file with the
68 * same name afterwards.
69 */
70 ret = utils_unlink_stream_file(fullpath, stream_name, size, count, uid,
71 gid, DEFAULT_INDEX_FILE_SUFFIX);
72 if (ret < 0 && errno != ENOENT) {
73 goto error;
74 }
75 ret = utils_create_stream_file(fullpath, stream_name, size, count, uid,
76 gid, DEFAULT_INDEX_FILE_SUFFIX);
77 if (ret < 0) {
78 goto error;
79 }
80 fd = ret;
81
82 hdr.magic = htobe32(CTF_INDEX_MAGIC);
83 hdr.index_major = htobe32(CTF_INDEX_MAJOR);
84 hdr.index_minor = htobe32(CTF_INDEX_MINOR);
85 hdr.packet_index_len = htobe32(sizeof(struct ctf_packet_index));
86
87 size_ret = lttng_write(fd, &hdr, sizeof(hdr));
88 if (size_ret < sizeof(hdr)) {
89 PERROR("write index header");
90 ret = -1;
91 goto error;
92 }
93
94 return fd;
95
96 error:
97 if (fd >= 0) {
98 int close_ret;
99
100 close_ret = close(fd);
101 if (close_ret < 0) {
102 PERROR("close index fd");
103 }
104 }
105 return ret;
106 }
107
108 /*
109 * Write index values to the given fd of size len.
110 *
111 * Return "len" on success or else < len on error. errno contains error
112 * details.
113 */
114 ssize_t index_write(int fd, struct ctf_packet_index *index, size_t len)
115 {
116 ssize_t ret;
117
118 assert(index);
119
120 if (fd < 0) {
121 ret = -EINVAL;
122 goto error;
123 }
124
125 ret = lttng_write(fd, index, len);
126 if (ret < len) {
127 PERROR("writing index file");
128 }
129
130 error:
131 return ret;
132 }
133
134 /*
135 * Open index file using a given path, channel name and tracefile count.
136 *
137 * Return read only FD on success or else a negative value.
138 */
139 int index_open(const char *path_name, const char *channel_name,
140 uint64_t tracefile_count, uint64_t tracefile_count_current)
141 {
142 int ret, read_fd;
143 ssize_t read_len;
144 char fullpath[PATH_MAX];
145 struct ctf_packet_index_file_hdr hdr;
146
147 assert(path_name);
148 assert(channel_name);
149
150 if (tracefile_count > 0) {
151 ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s_%"
152 PRIu64 DEFAULT_INDEX_FILE_SUFFIX, path_name,
153 channel_name, tracefile_count_current);
154 } else {
155 ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s"
156 DEFAULT_INDEX_FILE_SUFFIX, path_name, channel_name);
157 }
158 if (ret < 0) {
159 PERROR("snprintf index path");
160 goto error;
161 }
162
163 DBG("Index opening file %s in read only", fullpath);
164 read_fd = open(fullpath, O_RDONLY);
165 if (read_fd < 0) {
166 if (errno == ENOENT) {
167 ret = -ENOENT;
168 } else {
169 PERROR("opening index in read-only");
170 }
171 goto error;
172 }
173
174 read_len = lttng_read(read_fd, &hdr, sizeof(hdr));
175 if (read_len < 0) {
176 PERROR("Reading index header");
177 goto error_close;
178 }
179
180 if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) {
181 ERR("Invalid header magic");
182 goto error_close;
183 }
184 if (be32toh(hdr.index_major) != CTF_INDEX_MAJOR ||
185 be32toh(hdr.index_minor) != CTF_INDEX_MINOR) {
186 ERR("Invalid header version");
187 goto error_close;
188 }
189
190 return read_fd;
191
192 error_close:
193 if (read_fd >= 0) {
194 int close_ret;
195
196 close_ret = close(read_fd);
197 if (close_ret < 0) {
198 PERROR("close read fd %d", read_fd);
199 }
200 }
201 ret = -1;
202
203 error:
204 return ret;
205 }
This page took 0.033129 seconds and 3 git commands to generate.