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Commit | Line | Data |
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a54d5262 DW |
1 | /* |
2 | * mdmon - monitor external metadata arrays | |
3 | * | |
e736b623 N |
4 | * Copyright (C) 2007-2009 Neil Brown <neilb@suse.de> |
5 | * Copyright (C) 2007-2009 Intel Corporation | |
a54d5262 DW |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms and conditions of the GNU General Public License, | |
9 | * version 2, as published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope it will be useful, but WITHOUT | |
12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
14 | * more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License along with | |
17 | * this program; if not, write to the Free Software Foundation, Inc., | |
18 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | |
19 | */ | |
549e9569 NB |
20 | |
21 | /* | |
22 | * md array manager. | |
23 | * When md arrays have user-space managed metadata, this is the program | |
24 | * that does the managing. | |
25 | * | |
26 | * Given one argument: the name of the array (e.g. /dev/md0) that is | |
27 | * the container. | |
28 | * We fork off a helper that runs high priority and mlocked. It responds to | |
29 | * device failures and other events that might stop writeout, or that are | |
30 | * trivial to deal with. | |
31 | * The main thread then watches for new arrays being created in the container | |
32 | * and starts monitoring them too ... along with a few other tasks. | |
33 | * | |
34 | * The main thread communicates with the priority thread by writing over | |
35 | * a pipe. | |
36 | * Separate programs can communicate with the main thread via Unix-domain | |
37 | * socket. | |
38 | * The two threads share address space and open file table. | |
39 | * | |
40 | */ | |
41 | ||
42 | #ifndef _GNU_SOURCE | |
43 | #define _GNU_SOURCE | |
44 | #endif | |
45 | ||
46 | #include <unistd.h> | |
47 | #include <stdlib.h> | |
4d43913c | 48 | #include <sys/types.h> |
549e9569 NB |
49 | #include <sys/stat.h> |
50 | #include <sys/socket.h> | |
51 | #include <sys/un.h> | |
52 | #include <sys/mman.h> | |
4d43913c | 53 | #include <sys/syscall.h> |
9fe32043 | 54 | #include <sys/wait.h> |
549e9569 NB |
55 | #include <stdio.h> |
56 | #include <errno.h> | |
57 | #include <string.h> | |
58 | #include <fcntl.h> | |
b109d928 | 59 | #include <signal.h> |
13047e4c | 60 | #include <dirent.h> |
549e9569 NB |
61 | |
62 | #include <sched.h> | |
63 | ||
64 | #include "mdadm.h" | |
65 | #include "mdmon.h" | |
66 | ||
549e9569 NB |
67 | struct active_array *discard_this; |
68 | struct active_array *pending_discard; | |
4d43913c NB |
69 | |
70 | int mon_tid, mgr_tid; | |
549e9569 | 71 | |
6144ed44 DW |
72 | int sigterm; |
73 | ||
549e9569 NB |
74 | int run_child(void *v) |
75 | { | |
76 | struct supertype *c = v; | |
1ed3f387 | 77 | |
549e9569 NB |
78 | do_monitor(c); |
79 | return 0; | |
80 | } | |
81 | ||
97f734fd N |
82 | #ifdef __ia64__ |
83 | int __clone2(int (*fn)(void *), | |
84 | void *child_stack_base, size_t stack_size, | |
85 | int flags, void *arg, ... | |
86 | /* pid_t *pid, struct user_desc *tls, pid_t *ctid */ ); | |
87 | #endif | |
88 | int clone_monitor(struct supertype *container) | |
549e9569 | 89 | { |
549e9569 | 90 | static char stack[4096]; |
549e9569 | 91 | |
97f734fd N |
92 | #ifdef __ia64__ |
93 | mon_tid = __clone2(run_child, stack, sizeof(stack), | |
94 | CLONE_FS|CLONE_FILES|CLONE_VM|CLONE_SIGHAND|CLONE_THREAD, | |
95 | container); | |
96 | #else | |
2cc98f9e | 97 | mon_tid = clone(run_child, stack+4096-64, |
549e9569 NB |
98 | CLONE_FS|CLONE_FILES|CLONE_VM|CLONE_SIGHAND|CLONE_THREAD, |
99 | container); | |
97f734fd | 100 | #endif |
3e70c845 | 101 | |
4d43913c | 102 | mgr_tid = syscall(SYS_gettid); |
2cc98f9e DW |
103 | |
104 | return mon_tid; | |
549e9569 NB |
105 | } |
106 | ||
ce744c97 DW |
107 | static struct superswitch *find_metadata_methods(char *vers) |
108 | { | |
109 | if (strcmp(vers, "ddf") == 0) | |
110 | return &super_ddf; | |
111 | if (strcmp(vers, "imsm") == 0) | |
112 | return &super_imsm; | |
113 | return NULL; | |
114 | } | |
115 | ||
fa716c83 | 116 | static int make_pidfile(char *devname) |
549e9569 NB |
117 | { |
118 | char path[100]; | |
119 | char pid[10]; | |
120 | int fd; | |
3d2c4fc7 DW |
121 | int n; |
122 | ||
ed8fa52f LB |
123 | if (mkdir(pid_dir, 0600) < 0 && |
124 | errno != EEXIST) | |
125 | return -errno; | |
5d4d1b26 | 126 | sprintf(path, "%s/%s.pid", pid_dir, devname); |
549e9569 | 127 | |
5d4d1b26 | 128 | fd = open(path, O_RDWR|O_CREAT|O_EXCL, 0600); |
549e9569 | 129 | if (fd < 0) |
295646b3 | 130 | return -errno; |
549e9569 | 131 | sprintf(pid, "%d\n", getpid()); |
3d2c4fc7 | 132 | n = write(fd, pid, strlen(pid)); |
549e9569 | 133 | close(fd); |
3d2c4fc7 DW |
134 | if (n < 0) |
135 | return -errno; | |
549e9569 NB |
136 | return 0; |
137 | } | |
138 | ||
883a6142 DW |
139 | int is_container_member(struct mdstat_ent *mdstat, char *container) |
140 | { | |
141 | if (mdstat->metadata_version == NULL || | |
142 | strncmp(mdstat->metadata_version, "external:", 9) != 0 || | |
143 | !is_subarray(mdstat->metadata_version+9) || | |
144 | strncmp(mdstat->metadata_version+10, container, strlen(container)) != 0 || | |
145 | mdstat->metadata_version[10+strlen(container)] != '/') | |
146 | return 0; | |
147 | ||
148 | return 1; | |
149 | } | |
150 | ||
9f1da824 | 151 | static void try_kill_monitor(pid_t pid, char *devname, int sock) |
96a8270d DW |
152 | { |
153 | char buf[100]; | |
154 | int fd; | |
417a4b04 | 155 | int n; |
af7ca334 | 156 | long fl; |
b109d928 | 157 | |
8aae4219 DW |
158 | /* first rule of survival... don't off yourself */ |
159 | if (pid == getpid()) | |
160 | return; | |
161 | ||
b109d928 DW |
162 | /* kill this process if it is mdmon */ |
163 | sprintf(buf, "/proc/%lu/cmdline", (unsigned long) pid); | |
164 | fd = open(buf, O_RDONLY); | |
165 | if (fd < 0) | |
166 | return; | |
167 | ||
417a4b04 N |
168 | n = read(fd, buf, sizeof(buf)-1); |
169 | buf[sizeof(buf)-1] = 0; | |
170 | close(fd); | |
b109d928 | 171 | |
417a4b04 | 172 | if (n < 0 || !strstr(buf, "mdmon")) |
883a6142 DW |
173 | return; |
174 | ||
175 | kill(pid, SIGTERM); | |
176 | ||
af7ca334 N |
177 | /* Wait for monitor to exit by reading from the socket, after |
178 | * clearing the non-blocking flag */ | |
179 | fl = fcntl(sock, F_GETFL, 0); | |
180 | fl &= ~O_NONBLOCK; | |
181 | fcntl(sock, F_SETFL, fl); | |
fcf57625 N |
182 | n = read(sock, buf, 100); |
183 | /* Ignore result, it is just the wait that | |
184 | * matters | |
185 | */ | |
b109d928 DW |
186 | } |
187 | ||
e0d6609f NB |
188 | void remove_pidfile(char *devname) |
189 | { | |
190 | char buf[100]; | |
191 | ||
5d4d1b26 | 192 | sprintf(buf, "%s/%s.pid", pid_dir, devname); |
e0d6609f | 193 | unlink(buf); |
5d4d1b26 | 194 | sprintf(buf, "%s/%s.sock", pid_dir, devname); |
57752795 | 195 | unlink(buf); |
5d4d1b26 N |
196 | if (strcmp(pid_dir, ALT_RUN) == 0) |
197 | /* try to clean up when we are finished with this dir */ | |
198 | rmdir(pid_dir); | |
e0d6609f NB |
199 | } |
200 | ||
fa716c83 | 201 | static int make_control_sock(char *devname) |
549e9569 NB |
202 | { |
203 | char path[100]; | |
204 | int sfd; | |
205 | long fl; | |
206 | struct sockaddr_un addr; | |
207 | ||
6144ed44 DW |
208 | if (sigterm) |
209 | return -1; | |
210 | ||
5d4d1b26 | 211 | sprintf(path, "%s/%s.sock", pid_dir, devname); |
549e9569 NB |
212 | unlink(path); |
213 | sfd = socket(PF_LOCAL, SOCK_STREAM, 0); | |
214 | if (sfd < 0) | |
215 | return -1; | |
216 | ||
217 | addr.sun_family = PF_LOCAL; | |
218 | strcpy(addr.sun_path, path); | |
219 | if (bind(sfd, &addr, sizeof(addr)) < 0) { | |
220 | close(sfd); | |
221 | return -1; | |
222 | } | |
223 | listen(sfd, 10); | |
224 | fl = fcntl(sfd, F_GETFL, 0); | |
225 | fl |= O_NONBLOCK; | |
226 | fcntl(sfd, F_SETFL, fl); | |
227 | return sfd; | |
228 | } | |
229 | ||
6144ed44 DW |
230 | static void term(int sig) |
231 | { | |
232 | sigterm = 1; | |
233 | } | |
234 | ||
4d43913c NB |
235 | static void wake_me(int sig) |
236 | { | |
237 | ||
238 | } | |
239 | ||
16ddab0d DW |
240 | /* if we are debugging and starting mdmon by hand then don't fork */ |
241 | static int do_fork(void) | |
242 | { | |
243 | #ifdef DEBUG | |
40ebbb9c | 244 | if (check_env("MDADM_NO_MDMON")) |
16ddab0d DW |
245 | return 0; |
246 | #endif | |
247 | ||
248 | return 1; | |
249 | } | |
250 | ||
13047e4c DW |
251 | void usage(void) |
252 | { | |
eb49460b | 253 | fprintf(stderr, "Usage: mdmon [--all] [--takeover] CONTAINER\n"); |
13047e4c DW |
254 | exit(2); |
255 | } | |
16ddab0d | 256 | |
b5c727dc | 257 | static int mdmon(char *devname, int devnum, int must_fork, int takeover); |
1ffd2840 | 258 | |
549e9569 NB |
259 | int main(int argc, char *argv[]) |
260 | { | |
13047e4c | 261 | char *container_name = NULL; |
e8a70c89 N |
262 | int devnum; |
263 | char *devname; | |
1ffd2840 | 264 | int status = 0; |
b5c727dc N |
265 | int arg; |
266 | int all = 0; | |
267 | int takeover = 0; | |
268 | ||
269 | for (arg = 1; arg < argc; arg++) { | |
eb49460b LB |
270 | if (strncmp(argv[arg], "--all",5) == 0 || |
271 | strcmp(argv[arg], "/proc/mdstat") == 0) { | |
272 | container_name = argv[arg]; | |
b5c727dc | 273 | all = 1; |
eb49460b | 274 | } else if (strcmp(argv[arg], "--takeover") == 0) |
b5c727dc N |
275 | takeover = 1; |
276 | else if (container_name == NULL) | |
277 | container_name = argv[arg]; | |
278 | else | |
279 | usage(); | |
549e9569 | 280 | } |
eb49460b LB |
281 | if (container_name == NULL) |
282 | usage(); | |
13047e4c | 283 | |
b5c727dc | 284 | if (all) { |
1ffd2840 | 285 | struct mdstat_ent *mdstat, *e; |
eb49460b | 286 | int container_len = strlen(container_name); |
1ffd2840 DW |
287 | |
288 | /* launch an mdmon instance for each container found */ | |
1ffd2840 DW |
289 | mdstat = mdstat_read(0, 0); |
290 | for (e = mdstat; e; e = e->next) { | |
291 | if (strncmp(e->metadata_version, "external:", 9) == 0 && | |
292 | !is_subarray(&e->metadata_version[9])) { | |
293 | devname = devnum2devname(e->devnum); | |
1b34f519 DW |
294 | /* update cmdline so this mdmon instance can be |
295 | * distinguished from others in a call to ps(1) | |
296 | */ | |
eb49460b LB |
297 | if (strlen(devname) <= container_len) { |
298 | memset(container_name, 0, container_len); | |
1b34f519 DW |
299 | sprintf(container_name, "%s", devname); |
300 | } | |
3e7312a9 | 301 | status |= mdmon(devname, e->devnum, 1, |
b5c727dc | 302 | takeover); |
1ffd2840 DW |
303 | } |
304 | } | |
305 | free_mdstat(mdstat); | |
306 | ||
307 | return status; | |
308 | } else if (strncmp(container_name, "md", 2) == 0) { | |
6f4098a6 DW |
309 | devnum = devname2devnum(container_name); |
310 | devname = devnum2devname(devnum); | |
311 | if (strcmp(container_name, devname) != 0) | |
312 | devname = NULL; | |
313 | } else { | |
314 | struct stat st; | |
315 | ||
316 | devnum = NoMdDev; | |
317 | if (stat(container_name, &st) == 0) | |
318 | devnum = stat2devnum(&st); | |
319 | if (devnum == NoMdDev) | |
320 | devname = NULL; | |
321 | else | |
322 | devname = devnum2devname(devnum); | |
323 | } | |
324 | ||
325 | if (!devname) { | |
e8a70c89 N |
326 | fprintf(stderr, "mdmon: %s is not a valid md device name\n", |
327 | container_name); | |
328 | exit(1); | |
329 | } | |
b5c727dc | 330 | return mdmon(devname, devnum, do_fork(), takeover); |
1ffd2840 DW |
331 | } |
332 | ||
b5c727dc | 333 | static int mdmon(char *devname, int devnum, int must_fork, int takeover) |
1ffd2840 DW |
334 | { |
335 | int mdfd; | |
336 | struct mdinfo *mdi, *di; | |
337 | struct supertype *container; | |
338 | sigset_t set; | |
339 | struct sigaction act; | |
340 | int pfd[2]; | |
341 | int status; | |
342 | int ignore; | |
96a8270d | 343 | pid_t victim = -1; |
9f1da824 | 344 | int victim_sock = -1; |
1ffd2840 | 345 | |
b5c727dc | 346 | dprintf("starting mdmon for %s\n", devname); |
b928b5a0 | 347 | |
e8a70c89 | 348 | mdfd = open_dev(devnum); |
549e9569 | 349 | if (mdfd < 0) { |
1ffd2840 | 350 | fprintf(stderr, "mdmon: %s: %s\n", devname, |
549e9569 | 351 | strerror(errno)); |
1ffd2840 | 352 | return 1; |
549e9569 NB |
353 | } |
354 | if (md_get_version(mdfd) < 0) { | |
13047e4c | 355 | fprintf(stderr, "mdmon: %s: Not an md device\n", |
1ffd2840 DW |
356 | devname); |
357 | return 1; | |
549e9569 NB |
358 | } |
359 | ||
9fe32043 | 360 | /* Fork, and have the child tell us when they are ready */ |
3e7312a9 | 361 | if (must_fork) { |
3d2c4fc7 DW |
362 | if (pipe(pfd) != 0) { |
363 | fprintf(stderr, "mdmon: failed to create pipe\n"); | |
1ffd2840 | 364 | return 1; |
3d2c4fc7 | 365 | } |
16ddab0d DW |
366 | switch(fork()) { |
367 | case -1: | |
368 | fprintf(stderr, "mdmon: failed to fork: %s\n", | |
369 | strerror(errno)); | |
1ffd2840 | 370 | return 1; |
16ddab0d DW |
371 | case 0: /* child */ |
372 | close(pfd[0]); | |
373 | break; | |
374 | default: /* parent */ | |
375 | close(pfd[1]); | |
376 | if (read(pfd[0], &status, sizeof(status)) != sizeof(status)) { | |
377 | wait(&status); | |
378 | status = WEXITSTATUS(status); | |
379 | } | |
1ffd2840 | 380 | return status; |
9fe32043 | 381 | } |
16ddab0d DW |
382 | } else |
383 | pfd[0] = pfd[1] = -1; | |
549e9569 | 384 | |
f5df5d69 | 385 | container = calloc(1, sizeof(*container)); |
e8a70c89 N |
386 | container->devnum = devnum; |
387 | container->devname = devname; | |
13047e4c | 388 | container->arrays = NULL; |
c1363b40 | 389 | container->subarray[0] = 0; |
96a8270d | 390 | container->sock = -1; |
13047e4c DW |
391 | |
392 | if (!container->devname) { | |
393 | fprintf(stderr, "mdmon: failed to allocate container name string\n"); | |
394 | exit(3); | |
395 | } | |
396 | ||
397 | mdi = sysfs_read(mdfd, container->devnum, | |
7da80e6f | 398 | GET_VERSION|GET_LEVEL|GET_DEVS|SKIP_GONE_DEVS); |
13047e4c DW |
399 | |
400 | if (!mdi) { | |
401 | fprintf(stderr, "mdmon: failed to load sysfs info for %s\n", | |
402 | container->devname); | |
403 | exit(3); | |
404 | } | |
405 | if (mdi->array.level != UnSet) { | |
406 | fprintf(stderr, "mdmon: %s is not a container - cannot monitor\n", | |
1ffd2840 | 407 | devname); |
13047e4c DW |
408 | exit(3); |
409 | } | |
410 | if (mdi->array.major_version != -1 || | |
411 | mdi->array.minor_version != -2) { | |
412 | fprintf(stderr, "mdmon: %s does not use external metadata - cannot monitor\n", | |
1ffd2840 | 413 | devname); |
13047e4c DW |
414 | exit(3); |
415 | } | |
416 | ||
417 | container->ss = find_metadata_methods(mdi->text_version); | |
418 | if (container->ss == NULL) { | |
419 | fprintf(stderr, "mdmon: %s uses unknown metadata: %s\n", | |
1ffd2840 | 420 | devname, mdi->text_version); |
13047e4c DW |
421 | exit(3); |
422 | } | |
423 | ||
424 | container->devs = NULL; | |
425 | for (di = mdi->devs; di; di = di->next) { | |
426 | struct mdinfo *cd = malloc(sizeof(*cd)); | |
427 | *cd = *di; | |
428 | cd->next = container->devs; | |
429 | container->devs = cd; | |
430 | } | |
431 | sysfs_free(mdi); | |
549e9569 | 432 | |
883a6142 DW |
433 | /* SIGUSR is sent between parent and child. So both block it |
434 | * and enable it only with pselect. | |
435 | */ | |
436 | sigemptyset(&set); | |
437 | sigaddset(&set, SIGUSR1); | |
883a6142 DW |
438 | sigaddset(&set, SIGTERM); |
439 | sigprocmask(SIG_BLOCK, &set, NULL); | |
440 | act.sa_handler = wake_me; | |
441 | act.sa_flags = 0; | |
442 | sigaction(SIGUSR1, &act, NULL); | |
883a6142 DW |
443 | act.sa_handler = term; |
444 | sigaction(SIGTERM, &act, NULL); | |
445 | act.sa_handler = SIG_IGN; | |
446 | sigaction(SIGPIPE, &act, NULL); | |
447 | ||
32f21701 N |
448 | pid_dir = VAR_RUN; |
449 | victim = mdmon_pid(container->devnum); | |
450 | if (victim < 0) { | |
451 | pid_dir = ALT_RUN; | |
b5c727dc | 452 | victim = mdmon_pid(container->devnum); |
13047e4c | 453 | } |
32f21701 N |
454 | if (victim >= 0) |
455 | victim_sock = connect_monitor(container->devname); | |
13047e4c | 456 | |
13047e4c | 457 | ignore = chdir("/"); |
32f21701 N |
458 | if (!takeover && victim > 0 && victim_sock >= 0) { |
459 | if (fping_monitor(victim_sock) == 0) { | |
b109d928 DW |
460 | fprintf(stderr, "mdmon: %s already managed\n", |
461 | container->devname); | |
462 | exit(3); | |
24cfdbc5 | 463 | } |
32f21701 | 464 | close(victim_sock); |
549e9569 | 465 | } |
1ffd2840 | 466 | if (container->ss->load_super(container, mdfd, devname)) { |
549e9569 | 467 | fprintf(stderr, "mdmon: Cannot load metadata for %s\n", |
1ffd2840 | 468 | devname); |
549e9569 NB |
469 | exit(3); |
470 | } | |
e8a70c89 | 471 | close(mdfd); |
549e9569 | 472 | |
9fe32043 N |
473 | /* Ok, this is close enough. We can say goodbye to our parent now. |
474 | */ | |
fa716c83 N |
475 | if (victim > 0) |
476 | remove_pidfile(devname); | |
ed8fa52f | 477 | pid_dir = VAR_RUN; |
fa716c83 | 478 | if (make_pidfile(devname) < 0) { |
ed8fa52f LB |
479 | /* Try the alternate */ |
480 | pid_dir = ALT_RUN; | |
481 | if (make_pidfile(devname) < 0) { | |
482 | fprintf(stderr, "mdmon: Neither %s nor %s are writable\n" | |
483 | " cannot create .pid or .sock files. Aborting\n", | |
484 | VAR_RUN, ALT_RUN); | |
485 | exit(3); | |
486 | } | |
fa716c83 N |
487 | } |
488 | container->sock = make_control_sock(devname); | |
489 | ||
9fe32043 | 490 | status = 0; |
3d2c4fc7 DW |
491 | if (write(pfd[1], &status, sizeof(status)) < 0) |
492 | fprintf(stderr, "mdmon: failed to notify our parent: %d\n", | |
493 | getppid()); | |
9fe32043 N |
494 | close(pfd[1]); |
495 | ||
1373b07d | 496 | mlockall(MCL_CURRENT | MCL_FUTURE); |
549e9569 | 497 | |
3e70c845 | 498 | if (clone_monitor(container) < 0) { |
295646b3 | 499 | fprintf(stderr, "mdmon: failed to start monitor process: %s\n", |
549e9569 NB |
500 | strerror(errno)); |
501 | exit(2); | |
502 | } | |
503 | ||
fa716c83 | 504 | if (victim > 0) { |
9f1da824 DW |
505 | try_kill_monitor(victim, container->devname, victim_sock); |
506 | close(victim_sock); | |
507 | } | |
e98ef225 N |
508 | |
509 | setsid(); | |
510 | close(0); | |
511 | open("/dev/null", O_RDWR); | |
512 | close(1); | |
513 | ignore = dup(0); | |
514 | #ifndef DEBUG | |
515 | close(2); | |
516 | ignore = dup(0); | |
517 | #endif | |
518 | ||
549e9569 NB |
519 | do_manager(container); |
520 | ||
521 | exit(0); | |
522 | } |