Contents of /tags/mkinitrd-6_1_4/busybox/runit/runsvdir.c
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Wed Aug 5 16:25:39 2009 UTC (15 years, 1 month ago) by niro
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Wed Aug 5 16:25:39 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 9643 byte(s)
tagged 'mkinitrd-6_1_4'
1 | /* |
2 | Copyright (c) 2001-2006, Gerrit Pape |
3 | All rights reserved. |
4 | |
5 | Redistribution and use in source and binary forms, with or without |
6 | modification, are permitted provided that the following conditions are met: |
7 | |
8 | 1. Redistributions of source code must retain the above copyright notice, |
9 | this list of conditions and the following disclaimer. |
10 | 2. Redistributions in binary form must reproduce the above copyright |
11 | notice, this list of conditions and the following disclaimer in the |
12 | documentation and/or other materials provided with the distribution. |
13 | 3. The name of the author may not be used to endorse or promote products |
14 | derived from this software without specific prior written permission. |
15 | |
16 | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
17 | WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
18 | MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
19 | EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
20 | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
21 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
22 | OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
23 | WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
24 | OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
25 | ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | */ |
27 | |
28 | /* Busyboxed by Denys Vlasenko <vda.linux@googlemail.com> */ |
29 | /* TODO: depends on runit_lib.c - review and reduce/eliminate */ |
30 | |
31 | #include <sys/poll.h> |
32 | #include <sys/file.h> |
33 | #include "libbb.h" |
34 | #include "runit_lib.h" |
35 | |
36 | #define MAXSERVICES 1000 |
37 | |
38 | /* Should be not needed - all dirs are on same FS, right? */ |
39 | #define CHECK_DEVNO_TOO 0 |
40 | |
41 | struct service { |
42 | #if CHECK_DEVNO_TOO |
43 | dev_t dev; |
44 | #endif |
45 | ino_t ino; |
46 | pid_t pid; |
47 | smallint isgone; |
48 | }; |
49 | |
50 | struct globals { |
51 | struct service *sv; |
52 | char *svdir; |
53 | int svnum; |
54 | #if ENABLE_FEATURE_RUNSVDIR_LOG |
55 | char *rplog; |
56 | int rploglen; |
57 | struct fd_pair logpipe; |
58 | struct pollfd pfd[1]; |
59 | unsigned stamplog; |
60 | #endif |
61 | }; |
62 | #define G (*(struct globals*)&bb_common_bufsiz1) |
63 | #define sv (G.sv ) |
64 | #define svdir (G.svdir ) |
65 | #define svnum (G.svnum ) |
66 | #define rplog (G.rplog ) |
67 | #define rploglen (G.rploglen ) |
68 | #define logpipe (G.logpipe ) |
69 | #define pfd (G.pfd ) |
70 | #define stamplog (G.stamplog ) |
71 | #define INIT_G() do { \ |
72 | } while (0) |
73 | |
74 | static void fatal2_cannot(const char *m1, const char *m2) |
75 | { |
76 | bb_perror_msg_and_die("%s: fatal: cannot %s%s", svdir, m1, m2); |
77 | /* was exiting 100 */ |
78 | } |
79 | static void warn3x(const char *m1, const char *m2, const char *m3) |
80 | { |
81 | bb_error_msg("%s: warning: %s%s%s", svdir, m1, m2, m3); |
82 | } |
83 | static void warn2_cannot(const char *m1, const char *m2) |
84 | { |
85 | warn3x("cannot ", m1, m2); |
86 | } |
87 | #if ENABLE_FEATURE_RUNSVDIR_LOG |
88 | static void warnx(const char *m1) |
89 | { |
90 | warn3x(m1, "", ""); |
91 | } |
92 | #endif |
93 | |
94 | /* inlining + vfork -> bigger code */ |
95 | static NOINLINE pid_t runsv(const char *name) |
96 | { |
97 | pid_t pid; |
98 | |
99 | /* If we got signaled, stop spawning children at once! */ |
100 | if (bb_got_signal) |
101 | return 0; |
102 | |
103 | pid = vfork(); |
104 | if (pid == -1) { |
105 | warn2_cannot("vfork", ""); |
106 | return 0; |
107 | } |
108 | if (pid == 0) { |
109 | /* child */ |
110 | if (option_mask32 & 1) /* -P option? */ |
111 | setsid(); |
112 | /* man execv: |
113 | * "Signals set to be caught by the calling process image |
114 | * shall be set to the default action in the new process image." |
115 | * Therefore, we do not need this: */ |
116 | #if 0 |
117 | bb_signals(0 |
118 | | (1 << SIGHUP) |
119 | | (1 << SIGTERM) |
120 | , SIG_DFL); |
121 | #endif |
122 | execlp("runsv", "runsv", name, NULL); |
123 | fatal2_cannot("start runsv ", name); |
124 | } |
125 | return pid; |
126 | } |
127 | |
128 | /* gcc 4.3.0 does better with NOINLINE */ |
129 | static NOINLINE int do_rescan(void) |
130 | { |
131 | DIR *dir; |
132 | direntry *d; |
133 | int i; |
134 | struct stat s; |
135 | int need_rescan = 0; |
136 | |
137 | dir = opendir("."); |
138 | if (!dir) { |
139 | warn2_cannot("open directory ", svdir); |
140 | return 1; /* need to rescan again soon */ |
141 | } |
142 | for (i = 0; i < svnum; i++) |
143 | sv[i].isgone = 1; |
144 | |
145 | while (1) { |
146 | errno = 0; |
147 | d = readdir(dir); |
148 | if (!d) |
149 | break; |
150 | if (d->d_name[0] == '.') |
151 | continue; |
152 | if (stat(d->d_name, &s) == -1) { |
153 | warn2_cannot("stat ", d->d_name); |
154 | continue; |
155 | } |
156 | if (!S_ISDIR(s.st_mode)) |
157 | continue; |
158 | /* Do we have this service listed already? */ |
159 | for (i = 0; i < svnum; i++) { |
160 | if ((sv[i].ino == s.st_ino) |
161 | #if CHECK_DEVNO_TOO |
162 | && (sv[i].dev == s.st_dev) |
163 | #endif |
164 | ) { |
165 | if (sv[i].pid == 0) /* restart if it has died */ |
166 | goto run_ith_sv; |
167 | sv[i].isgone = 0; /* "we still see you" */ |
168 | goto next_dentry; |
169 | } |
170 | } |
171 | { /* Not found, make new service */ |
172 | struct service *svnew = realloc(sv, (i+1) * sizeof(*sv)); |
173 | if (!svnew) { |
174 | warn2_cannot("start runsv ", d->d_name); |
175 | need_rescan = 1; |
176 | continue; |
177 | } |
178 | sv = svnew; |
179 | svnum++; |
180 | #if CHECK_DEVNO_TOO |
181 | sv[i].dev = s.st_dev; |
182 | #endif |
183 | sv[i].ino = s.st_ino; |
184 | run_ith_sv: |
185 | sv[i].pid = runsv(d->d_name); |
186 | sv[i].isgone = 0; |
187 | } |
188 | next_dentry: ; |
189 | } |
190 | i = errno; |
191 | closedir(dir); |
192 | if (i) { /* readdir failed */ |
193 | warn2_cannot("read directory ", svdir); |
194 | return 1; /* need to rescan again soon */ |
195 | } |
196 | |
197 | /* Send SIGTERM to runsv whose directories |
198 | * were no longer found (-> must have been removed) */ |
199 | for (i = 0; i < svnum; i++) { |
200 | if (!sv[i].isgone) |
201 | continue; |
202 | if (sv[i].pid) |
203 | kill(sv[i].pid, SIGTERM); |
204 | svnum--; |
205 | sv[i] = sv[svnum]; |
206 | i--; /* so that we don't skip new sv[i] (bug was here!) */ |
207 | } |
208 | return need_rescan; |
209 | } |
210 | |
211 | int runsvdir_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
212 | int runsvdir_main(int argc UNUSED_PARAM, char **argv) |
213 | { |
214 | struct stat s; |
215 | dev_t last_dev = last_dev; /* for gcc */ |
216 | ino_t last_ino = last_ino; /* for gcc */ |
217 | time_t last_mtime = 0; |
218 | int wstat; |
219 | int curdir; |
220 | pid_t pid; |
221 | unsigned deadline; |
222 | unsigned now; |
223 | unsigned stampcheck; |
224 | int i; |
225 | int need_rescan = 1; |
226 | char *opt_s_argv[3]; |
227 | |
228 | INIT_G(); |
229 | |
230 | opt_complementary = "-1"; |
231 | opt_s_argv[0] = NULL; |
232 | opt_s_argv[2] = NULL; |
233 | getopt32(argv, "Ps:", &opt_s_argv[0]); |
234 | argv += optind; |
235 | |
236 | bb_signals(0 |
237 | | (1 << SIGTERM) |
238 | | (1 << SIGHUP) |
239 | /* For busybox's init, SIGTERM == reboot, |
240 | * SIGUSR1 == halt |
241 | * SIGUSR2 == poweroff |
242 | * so we need to intercept SIGUSRn too. |
243 | * Note that we do not implement actual reboot |
244 | * (killall(TERM) + umount, etc), we just pause |
245 | * respawing and avoid exiting (-> making kernel oops). |
246 | * The user is responsible for the rest. */ |
247 | | (getpid() == 1 ? ((1 << SIGUSR1) | (1 << SIGUSR2)) : 0) |
248 | , record_signo); |
249 | svdir = *argv++; |
250 | |
251 | #if ENABLE_FEATURE_RUNSVDIR_LOG |
252 | /* setup log */ |
253 | if (*argv) { |
254 | rplog = *argv; |
255 | rploglen = strlen(rplog); |
256 | if (rploglen < 7) { |
257 | warnx("log must have at least seven characters"); |
258 | } else if (piped_pair(logpipe)) { |
259 | warnx("cannot create pipe for log"); |
260 | } else { |
261 | close_on_exec_on(logpipe.rd); |
262 | close_on_exec_on(logpipe.wr); |
263 | ndelay_on(logpipe.rd); |
264 | ndelay_on(logpipe.wr); |
265 | if (dup2(logpipe.wr, 2) == -1) { |
266 | warnx("cannot set filedescriptor for log"); |
267 | } else { |
268 | pfd[0].fd = logpipe.rd; |
269 | pfd[0].events = POLLIN; |
270 | stamplog = monotonic_sec(); |
271 | goto run; |
272 | } |
273 | } |
274 | rplog = NULL; |
275 | warnx("log service disabled"); |
276 | } |
277 | run: |
278 | #endif |
279 | curdir = open_read("."); |
280 | if (curdir == -1) |
281 | fatal2_cannot("open current directory", ""); |
282 | close_on_exec_on(curdir); |
283 | |
284 | stampcheck = monotonic_sec(); |
285 | |
286 | for (;;) { |
287 | /* collect children */ |
288 | for (;;) { |
289 | pid = wait_any_nohang(&wstat); |
290 | if (pid <= 0) |
291 | break; |
292 | for (i = 0; i < svnum; i++) { |
293 | if (pid == sv[i].pid) { |
294 | /* runsv has died */ |
295 | sv[i].pid = 0; |
296 | need_rescan = 1; |
297 | } |
298 | } |
299 | } |
300 | |
301 | now = monotonic_sec(); |
302 | if ((int)(now - stampcheck) >= 0) { |
303 | /* wait at least a second */ |
304 | stampcheck = now + 1; |
305 | |
306 | if (stat(svdir, &s) != -1) { |
307 | if (need_rescan || s.st_mtime != last_mtime |
308 | || s.st_ino != last_ino || s.st_dev != last_dev |
309 | ) { |
310 | /* svdir modified */ |
311 | if (chdir(svdir) != -1) { |
312 | last_mtime = s.st_mtime; |
313 | last_dev = s.st_dev; |
314 | last_ino = s.st_ino; |
315 | //if (now <= mtime) |
316 | // sleep(1); |
317 | need_rescan = do_rescan(); |
318 | while (fchdir(curdir) == -1) { |
319 | warn2_cannot("change directory, pausing", ""); |
320 | sleep(5); |
321 | } |
322 | } else { |
323 | warn2_cannot("change directory to ", svdir); |
324 | } |
325 | } |
326 | } else { |
327 | warn2_cannot("stat ", svdir); |
328 | } |
329 | } |
330 | |
331 | #if ENABLE_FEATURE_RUNSVDIR_LOG |
332 | if (rplog) { |
333 | if ((int)(now - stamplog) >= 0) { |
334 | write(logpipe.wr, ".", 1); |
335 | stamplog = now + 900; |
336 | } |
337 | } |
338 | pfd[0].revents = 0; |
339 | #endif |
340 | deadline = (need_rescan ? 1 : 5); |
341 | sig_block(SIGCHLD); |
342 | #if ENABLE_FEATURE_RUNSVDIR_LOG |
343 | if (rplog) |
344 | poll(pfd, 1, deadline*1000); |
345 | else |
346 | #endif |
347 | sleep(deadline); |
348 | sig_unblock(SIGCHLD); |
349 | |
350 | #if ENABLE_FEATURE_RUNSVDIR_LOG |
351 | if (pfd[0].revents & POLLIN) { |
352 | char ch; |
353 | while (read(logpipe.rd, &ch, 1) > 0) { |
354 | if (ch < ' ') |
355 | ch = ' '; |
356 | for (i = 6; i < rploglen; i++) |
357 | rplog[i-1] = rplog[i]; |
358 | rplog[rploglen-1] = ch; |
359 | } |
360 | } |
361 | #endif |
362 | if (!bb_got_signal) |
363 | continue; |
364 | |
365 | /* -s SCRIPT: useful if we are init. |
366 | * In this case typically script never returns, |
367 | * it halts/powers off/reboots the system. */ |
368 | if (opt_s_argv[0]) { |
369 | /* Single parameter: signal# */ |
370 | opt_s_argv[1] = utoa(bb_got_signal); |
371 | pid = spawn(opt_s_argv); |
372 | if (pid > 0) { |
373 | /* Remebering to wait for _any_ children, |
374 | * not just pid */ |
375 | while (wait(NULL) != pid) |
376 | continue; |
377 | } |
378 | } |
379 | |
380 | switch (bb_got_signal) { |
381 | case SIGHUP: |
382 | for (i = 0; i < svnum; i++) |
383 | if (sv[i].pid) |
384 | kill(sv[i].pid, SIGTERM); |
385 | /* Fall through */ |
386 | default: /* SIGTERM (or SIGUSRn if we are init) */ |
387 | /* Exit unless we are init */ |
388 | if (getpid() == 1) |
389 | break; |
390 | return (SIGHUP == bb_got_signal) ? 111 : EXIT_SUCCESS; |
391 | } |
392 | |
393 | bb_got_signal = 0; |
394 | } /* for (;;) */ |
395 | } |