mdmon: fork and run as a daemon.
start_mdmon now waits for mdmon to complete initialisation and,
importantly, listen on the socket, before continuing.
Signed-off-by: Neil Brown <neilb@suse.de>
NeilBrown
15 years ago
| 31 | 31 |
#include <sys/un.h>
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| 32 | 32 |
#include <sys/mman.h>
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| 33 | 33 |
#include <sys/syscall.h>
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34 |
#include <sys/wait.h>
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#include <stdio.h>
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#include <errno.h>
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#include <string.h>
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| 174 | 175 |
struct supertype *container;
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| 175 | 176 |
sigset_t set;
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| 176 | 177 |
struct sigaction act;
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178 |
int pfd[2];
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179 |
int status;
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| 177 | 180 |
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if (argc != 2) {
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| 179 | 182 |
fprintf(stderr, "Usage: md-manage /device/name/for/container\n");
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| 191 | 194 |
exit(1);
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| 192 | 195 |
}
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| 193 | 196 |
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197 |
/* Fork, and have the child tell us when they are ready */
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pipe(pfd);
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199 |
switch(fork()){
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case -1:
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201 |
fprintf(stderr, "mdmon: failed to fork: %s\n",
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strerror(errno));
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exit(1);
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case 0: /* child */
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close(pfd[0]);
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break;
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default: /* parent */
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208 |
close(pfd[1]);
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209 |
if (read(pfd[0], &status, sizeof(status)) != sizeof(status)) {
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210 |
wait(&status);
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211 |
status = WEXITSTATUS(status);
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}
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exit(status);
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}
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| 194 | 215 |
/* hopefully it is a container - we'll check later */
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| 195 | 216 |
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| 196 | 217 |
container = malloc(sizeof(*container));
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| 267 | 288 |
exit(3);
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| 268 | 289 |
}
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| 269 | 290 |
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291 |
/* Ok, this is close enough. We can say goodbye to our parent now.
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*/
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293 |
status = 0;
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294 |
write(pfd[1], &status, sizeof(status));
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295 |
close(pfd[1]);
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296 |
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297 |
chdir("/");
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298 |
setsid();
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299 |
close(0);
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300 |
open("/dev/null", O_RDWR);
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301 |
close(1);
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302 |
dup(0);
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303 |
#ifndef DEBUG
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304 |
close(2);
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305 |
dup(0);
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306 |
#endif
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307 |
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| 270 | 308 |
mlockall(MCL_FUTURE);
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| 271 | 309 |
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| 272 | 310 |
/* SIGUSR is sent between parent and child. So both block it
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