Commit | Line | Data |
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7591bab1 MD |
1 | /* |
2 | * Copyright (C) 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
bdafebb5 | 3 | * 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com> |
7591bab1 MD |
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 | ||
7591bab1 | 19 | #define _LGPL_SOURCE |
bdafebb5 JG |
20 | |
21 | #include <urcu/ref.h> | |
22 | #include <sys/stat.h> | |
23 | #include <fcntl.h> | |
7591bab1 | 24 | #include <common/common.h> |
bdafebb5 JG |
25 | #include <common/fd-tracker/fd-tracker.h> |
26 | #include <common/fd-tracker/utils.h> | |
27 | #include <common/utils.h> | |
7591bab1 MD |
28 | |
29 | #include "stream-fd.h" | |
bdafebb5 JG |
30 | #include "lttng-relayd.h" |
31 | ||
32 | struct stream_fd { | |
c78608f0 | 33 | struct fs_handle *handle; |
bdafebb5 JG |
34 | struct urcu_ref ref; |
35 | }; | |
7591bab1 | 36 | |
bdafebb5 | 37 | static struct stream_fd *_stream_fd_alloc(void) |
7591bab1 MD |
38 | { |
39 | struct stream_fd *sf; | |
40 | ||
41 | sf = zmalloc(sizeof(*sf)); | |
42 | if (!sf) { | |
43 | goto end; | |
44 | } | |
45 | urcu_ref_init(&sf->ref); | |
7591bab1 MD |
46 | end: |
47 | return sf; | |
48 | } | |
49 | ||
bdafebb5 JG |
50 | static struct stream_fd *stream_fd_suspendable_create(struct fs_handle *handle) |
51 | { | |
52 | struct stream_fd *stream_fd = _stream_fd_alloc(); | |
53 | ||
54 | if (!stream_fd) { | |
55 | goto end; | |
56 | } | |
57 | ||
c78608f0 | 58 | stream_fd->handle = handle; |
bdafebb5 JG |
59 | end: |
60 | return stream_fd; | |
61 | } | |
62 | ||
bdafebb5 JG |
63 | struct stream_fd *stream_fd_open(const char *path) |
64 | { | |
bdafebb5 | 65 | struct stream_fd *stream_fd = NULL; |
c78608f0 JG |
66 | int flags = O_RDONLY; |
67 | struct fs_handle *handle; | |
bdafebb5 | 68 | |
c78608f0 JG |
69 | handle = fd_tracker_open_fs_handle(the_fd_tracker, path, |
70 | flags, NULL); | |
71 | if (!handle) { | |
bdafebb5 JG |
72 | goto end; |
73 | } | |
74 | ||
c78608f0 | 75 | stream_fd = stream_fd_suspendable_create(handle); |
bdafebb5 | 76 | if (!stream_fd) { |
c78608f0 JG |
77 | int close_ret; |
78 | ||
79 | close_ret = fs_handle_close(handle); | |
80 | if (close_ret) { | |
81 | ERR("Failed to close filesystem handle of stream at %s", path); | |
82 | } | |
bdafebb5 JG |
83 | } |
84 | end: | |
85 | return stream_fd; | |
86 | } | |
87 | ||
88 | static | |
c78608f0 | 89 | struct fs_handle *create_write_fs_handle(const char *path) |
bdafebb5 JG |
90 | { |
91 | struct fs_handle *handle; | |
92 | /* | |
93 | * With the session rotation feature on the relay, we might need to seek | |
94 | * and truncate a tracefile, so we need read and write access. | |
95 | */ | |
96 | int flags = O_RDWR | O_CREAT | O_TRUNC; | |
97 | /* Open with 660 mode */ | |
98 | mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP; | |
99 | ||
c78608f0 | 100 | handle = fd_tracker_open_fs_handle(the_fd_tracker, path, flags, &mode); |
bdafebb5 JG |
101 | if (!handle) { |
102 | ERR("Failed to open fs handle to %s", path); | |
103 | } | |
104 | ||
105 | return handle; | |
106 | } | |
107 | ||
108 | /* | |
109 | * Stream file are created by on the consumerd/data-reception end. Those | |
110 | * stream fds can be suspended as there is no expectation that the files | |
111 | * will be unlinked and then need to be appended-to. | |
112 | * | |
113 | * Hence, the file descriptors are created as suspendable to allow the | |
114 | * fd-tracker to reduce the number of active fds.. | |
115 | */ | |
116 | struct stream_fd *stream_fd_create(const char *path_name, const char *file_name, | |
117 | uint64_t size, uint64_t count, const char *suffix) | |
118 | { | |
119 | struct stream_fd *stream_fd = NULL; | |
120 | struct fs_handle *handle; | |
121 | int ret; | |
122 | char path[PATH_MAX]; | |
123 | ||
124 | ret = utils_stream_file_name(path, path_name, file_name, | |
125 | size, count, suffix); | |
126 | if (ret < 0) { | |
127 | goto end; | |
128 | } | |
129 | ||
c78608f0 | 130 | handle = create_write_fs_handle(path); |
bdafebb5 JG |
131 | if (!handle) { |
132 | goto end; | |
133 | } | |
134 | ||
135 | stream_fd = stream_fd_suspendable_create(handle); | |
136 | if (!stream_fd) { | |
c78608f0 JG |
137 | int close_ret; |
138 | ||
139 | close_ret = fs_handle_close(handle); | |
140 | if (close_ret) { | |
141 | ERR("Failed to close filesystem handle of stream at %s", path); | |
142 | } | |
bdafebb5 JG |
143 | } |
144 | ||
145 | end: | |
146 | return stream_fd; | |
147 | } | |
148 | ||
c78608f0 JG |
149 | /* |
150 | * This unlink wrapper allows the fd_tracker to check if any other | |
151 | * fs_handle references the stream before unlinking it. If the relay holds | |
152 | * this file open, it is essential to unlink it through an fs_handle as this | |
153 | * will delay the actual unlink() until all handles have released this file. | |
154 | * | |
155 | * The file is renamed and unlinked once the last handle to its inode has been | |
156 | * released. | |
157 | */ | |
158 | static | |
159 | int unlink_through_handle(const char *path) | |
160 | { | |
161 | int ret = 0, close_ret; | |
162 | struct fs_handle *handle; | |
163 | /* | |
164 | * Since this operation is only performed to perform the unlink | |
165 | * through the fs_handle and fd-tracker system, the flag is opened | |
166 | * without the O_CREAT. There is no need to perform the unlink if | |
167 | * the file doesn't already exist. | |
168 | */ | |
169 | int flags = O_RDONLY; | |
170 | ||
171 | DBG("Unlinking stream at %s through a filesystem handle", path); | |
172 | handle = fd_tracker_open_fs_handle(the_fd_tracker, path, flags, NULL); | |
173 | if (!handle) { | |
174 | /* There is nothing to do. */ | |
175 | DBG("File %s does not exist, ignoring unlink", path); | |
176 | goto end; | |
177 | } | |
178 | ||
179 | ret = fs_handle_unlink(handle); | |
180 | close_ret = fs_handle_close(handle); | |
181 | if (close_ret) { | |
182 | ERR("Failed to close handle after performing an unlink operation on a filesystem handle"); | |
183 | } | |
184 | end: | |
185 | if (ret) { | |
186 | DBG("Unlinking stream at %s failed with error code %i", path, ret); | |
187 | } | |
188 | return ret; | |
189 | } | |
190 | ||
bdafebb5 JG |
191 | int stream_fd_rotate(struct stream_fd *stream_fd, const char *path_name, |
192 | const char *file_name, uint64_t size, | |
193 | uint64_t count, uint64_t *new_count) | |
194 | { | |
195 | int ret; | |
196 | bool should_unlink; | |
197 | char path[PATH_MAX]; | |
198 | ||
199 | assert(stream_fd); | |
bdafebb5 JG |
200 | |
201 | utils_stream_file_rotation_get_new_count(count, new_count, | |
202 | &should_unlink); | |
203 | ||
204 | ret = utils_stream_file_name(path, path_name, file_name, | |
205 | size, count, NULL); | |
206 | if (ret < 0) { | |
207 | goto error; | |
208 | } | |
209 | ||
c78608f0 JG |
210 | ret = fs_handle_close(stream_fd->handle); |
211 | stream_fd->handle = NULL; | |
bdafebb5 JG |
212 | if (ret < 0) { |
213 | PERROR("Closing stream tracefile handle"); | |
214 | goto error; | |
215 | } | |
c78608f0 | 216 | |
bdafebb5 | 217 | if (should_unlink) { |
c78608f0 JG |
218 | ret = unlink_through_handle(path); |
219 | if (ret < 0) { | |
bdafebb5 JG |
220 | goto error; |
221 | } | |
222 | } | |
223 | ||
224 | ret = utils_stream_file_name(path, path_name, file_name, | |
225 | size, new_count ? *new_count : 0, NULL); | |
226 | if (ret < 0) { | |
227 | goto error; | |
228 | } | |
229 | ||
c78608f0 JG |
230 | stream_fd->handle = create_write_fs_handle(path); |
231 | if (!stream_fd->handle) { | |
bdafebb5 JG |
232 | ret = -1; |
233 | goto error; | |
234 | } | |
235 | ||
236 | ret = 0; | |
237 | ||
238 | error: | |
239 | return ret; | |
240 | } | |
241 | ||
7591bab1 MD |
242 | void stream_fd_get(struct stream_fd *sf) |
243 | { | |
244 | urcu_ref_get(&sf->ref); | |
245 | } | |
246 | ||
247 | static void stream_fd_release(struct urcu_ref *ref) | |
248 | { | |
249 | struct stream_fd *sf = caa_container_of(ref, struct stream_fd, ref); | |
250 | int ret; | |
251 | ||
c78608f0 | 252 | ret = fs_handle_close(sf->handle); |
7591bab1 | 253 | if (ret) { |
bdafebb5 | 254 | PERROR("Error closing stream handle"); |
7591bab1 MD |
255 | } |
256 | free(sf); | |
257 | } | |
258 | ||
259 | void stream_fd_put(struct stream_fd *sf) | |
260 | { | |
261 | urcu_ref_put(&sf->ref, stream_fd_release); | |
262 | } | |
bdafebb5 JG |
263 | |
264 | int stream_fd_get_fd(struct stream_fd *sf) | |
265 | { | |
c78608f0 | 266 | return fs_handle_get_fd(sf->handle); |
bdafebb5 JG |
267 | } |
268 | ||
269 | void stream_fd_put_fd(struct stream_fd *sf) | |
270 | { | |
c78608f0 | 271 | fs_handle_put_fd(sf->handle); |
bdafebb5 | 272 | } |