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Commit | Line | Data |
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549e9569 NB |
1 | |
2 | /* | |
3 | * md array manager. | |
4 | * When md arrays have user-space managed metadata, this is the program | |
5 | * that does the managing. | |
6 | * | |
7 | * Given one argument: the name of the array (e.g. /dev/md0) that is | |
8 | * the container. | |
9 | * We fork off a helper that runs high priority and mlocked. It responds to | |
10 | * device failures and other events that might stop writeout, or that are | |
11 | * trivial to deal with. | |
12 | * The main thread then watches for new arrays being created in the container | |
13 | * and starts monitoring them too ... along with a few other tasks. | |
14 | * | |
15 | * The main thread communicates with the priority thread by writing over | |
16 | * a pipe. | |
17 | * Separate programs can communicate with the main thread via Unix-domain | |
18 | * socket. | |
19 | * The two threads share address space and open file table. | |
20 | * | |
21 | */ | |
22 | ||
23 | #ifndef _GNU_SOURCE | |
24 | #define _GNU_SOURCE | |
25 | #endif | |
26 | ||
27 | #include <unistd.h> | |
28 | #include <stdlib.h> | |
29 | #include <sys/stat.h> | |
30 | #include <sys/socket.h> | |
31 | #include <sys/un.h> | |
32 | #include <sys/mman.h> | |
33 | #include <stdio.h> | |
34 | #include <errno.h> | |
35 | #include <string.h> | |
36 | #include <fcntl.h> | |
b109d928 | 37 | #include <signal.h> |
549e9569 NB |
38 | |
39 | #include <sched.h> | |
40 | ||
41 | #include "mdadm.h" | |
42 | #include "mdmon.h" | |
43 | ||
549e9569 NB |
44 | struct active_array *discard_this; |
45 | struct active_array *pending_discard; | |
3e70c845 | 46 | struct md_generic_cmd *active_cmd; |
549e9569 NB |
47 | |
48 | int run_child(void *v) | |
49 | { | |
50 | struct supertype *c = v; | |
1ed3f387 NB |
51 | sigset_t set; |
52 | /* SIGUSR is sent from child to parent, So child must block it */ | |
53 | sigemptyset(&set); | |
54 | sigaddset(&set, SIGUSR1); | |
55 | sigprocmask(SIG_BLOCK, &set, NULL); | |
56 | ||
549e9569 NB |
57 | do_monitor(c); |
58 | return 0; | |
59 | } | |
60 | ||
61 | int clone_monitor(struct supertype *container) | |
62 | { | |
549e9569 NB |
63 | static char stack[4096]; |
64 | int rv; | |
65 | ||
3e70c845 DW |
66 | rv = pipe(container->mgr_pipe); |
67 | if (rv < 0) | |
68 | return rv; | |
69 | rv = pipe(container->mon_pipe); | |
70 | if (rv < 0) | |
71 | goto err_mon_pipe; | |
549e9569 NB |
72 | |
73 | rv = clone(run_child, stack+4096-64, | |
74 | CLONE_FS|CLONE_FILES|CLONE_VM|CLONE_SIGHAND|CLONE_THREAD, | |
75 | container); | |
549e9569 | 76 | if (rv < 0) |
3e70c845 DW |
77 | goto err_clone; |
78 | else | |
549e9569 | 79 | return rv; |
3e70c845 DW |
80 | |
81 | err_clone: | |
82 | close(container->mon_pipe[0]); | |
83 | close(container->mon_pipe[1]); | |
84 | err_mon_pipe: | |
85 | close(container->mgr_pipe[0]); | |
86 | close(container->mgr_pipe[1]); | |
87 | ||
88 | return rv; | |
549e9569 NB |
89 | } |
90 | ||
91 | static struct superswitch *find_metadata_methods(char *vers) | |
92 | { | |
93 | if (strcmp(vers, "ddf") == 0) | |
94 | return &super_ddf; | |
5b65005f DW |
95 | if (strcmp(vers, "imsm") == 0) |
96 | return &super_imsm; | |
549e9569 NB |
97 | return NULL; |
98 | } | |
99 | ||
100 | ||
b109d928 | 101 | static int make_pidfile(char *devname, int o_excl) |
549e9569 NB |
102 | { |
103 | char path[100]; | |
104 | char pid[10]; | |
105 | int fd; | |
106 | sprintf(path, "/var/run/mdadm/%s.pid", devname); | |
107 | ||
b109d928 | 108 | fd = open(path, O_RDWR|O_CREAT|o_excl, 0600); |
549e9569 NB |
109 | if (fd < 0) |
110 | return -1; | |
111 | sprintf(pid, "%d\n", getpid()); | |
112 | write(fd, pid, strlen(pid)); | |
113 | close(fd); | |
114 | return 0; | |
115 | } | |
116 | ||
b109d928 DW |
117 | static void try_kill_monitor(char *devname) |
118 | { | |
119 | char buf[100]; | |
120 | int fd; | |
121 | pid_t pid; | |
122 | ||
123 | sprintf(buf, "/var/run/mdadm/%s.pid", devname); | |
124 | fd = open(buf, O_RDONLY); | |
125 | if (fd < 0) | |
126 | return; | |
127 | ||
128 | if (read(fd, buf, sizeof(buf)) < 0) { | |
129 | close(fd); | |
130 | return; | |
131 | } | |
132 | ||
133 | close(fd); | |
134 | pid = strtoul(buf, NULL, 10); | |
135 | ||
136 | /* kill this process if it is mdmon */ | |
137 | sprintf(buf, "/proc/%lu/cmdline", (unsigned long) pid); | |
138 | fd = open(buf, O_RDONLY); | |
139 | if (fd < 0) | |
140 | return; | |
141 | ||
142 | if (read(fd, buf, sizeof(buf)) < 0) { | |
143 | close(fd); | |
144 | return; | |
145 | } | |
146 | ||
147 | if (strstr(buf, "mdmon") != NULL) | |
148 | kill(pid, SIGTERM); | |
149 | } | |
150 | ||
e0d6609f NB |
151 | void remove_pidfile(char *devname) |
152 | { | |
153 | char buf[100]; | |
154 | ||
155 | sprintf(buf, "/var/run/mdadm/%s.pid", devname); | |
156 | unlink(buf); | |
157 | } | |
158 | ||
549e9569 NB |
159 | static int make_control_sock(char *devname) |
160 | { | |
161 | char path[100]; | |
162 | int sfd; | |
163 | long fl; | |
164 | struct sockaddr_un addr; | |
165 | ||
166 | sprintf(path, "/var/run/mdadm/%s.sock", devname); | |
167 | unlink(path); | |
168 | sfd = socket(PF_LOCAL, SOCK_STREAM, 0); | |
169 | if (sfd < 0) | |
170 | return -1; | |
171 | ||
172 | addr.sun_family = PF_LOCAL; | |
173 | strcpy(addr.sun_path, path); | |
174 | if (bind(sfd, &addr, sizeof(addr)) < 0) { | |
175 | close(sfd); | |
176 | return -1; | |
177 | } | |
178 | listen(sfd, 10); | |
179 | fl = fcntl(sfd, F_GETFL, 0); | |
180 | fl |= O_NONBLOCK; | |
181 | fcntl(sfd, F_SETFL, fl); | |
182 | return sfd; | |
183 | } | |
184 | ||
185 | int main(int argc, char *argv[]) | |
186 | { | |
187 | int mdfd; | |
549e9569 NB |
188 | struct mdinfo *mdi, *di; |
189 | struct supertype *container; | |
190 | if (argc != 2) { | |
191 | fprintf(stderr, "Usage: md-manage /device/name/for/container\n"); | |
192 | exit(2); | |
193 | } | |
194 | mdfd = open(argv[1], O_RDWR); | |
195 | if (mdfd < 0) { | |
196 | fprintf(stderr, "md-manage: %s: %s\n", argv[1], | |
197 | strerror(errno)); | |
198 | exit(1); | |
199 | } | |
200 | if (md_get_version(mdfd) < 0) { | |
201 | fprintf(stderr, "md-manage: %s: Not an md device\n", | |
202 | argv[1]); | |
203 | exit(1); | |
204 | } | |
205 | ||
206 | /* hopefully it is a container - we'll check later */ | |
207 | ||
208 | container = malloc(sizeof(*container)); | |
549e9569 NB |
209 | container->devnum = fd2devnum(mdfd); |
210 | container->devname = devnum2devname(container->devnum); | |
e0d6609f | 211 | container->device_name = argv[1]; |
549e9569 NB |
212 | |
213 | /* If this fails, we hope it already exists */ | |
214 | mkdir("/var/run/mdadm", 0600); | |
215 | /* pid file lives in /var/run/mdadm/mdXX.pid */ | |
b109d928 DW |
216 | if (make_pidfile(container->devname, O_EXCL) < 0) { |
217 | if (ping_monitor(container->devname) == 0) { | |
218 | fprintf(stderr, "mdmon: %s already managed\n", | |
219 | container->devname); | |
220 | exit(3); | |
221 | } else { | |
222 | /* cleanup the old monitor, this one is taking over */ | |
223 | try_kill_monitor(container->devname); | |
224 | if (make_pidfile(container->devname, 0) < 0) { | |
225 | fprintf(stderr, "mdmon: %s Cannot create pidfile\n", | |
226 | container->devname); | |
227 | exit(3); | |
228 | } | |
229 | } | |
549e9569 NB |
230 | } |
231 | ||
232 | container->sock = make_control_sock(container->devname); | |
233 | if (container->sock < 0) { | |
234 | fprintf(stderr, "mdmon: Cannot create socket in /var/run/mdadm\n"); | |
235 | exit(3); | |
236 | } | |
237 | container->arrays = NULL; | |
238 | ||
239 | mdi = sysfs_read(mdfd, container->devnum, | |
240 | GET_VERSION|GET_LEVEL|GET_DEVS); | |
241 | ||
242 | if (!mdi) { | |
243 | fprintf(stderr, "mdmon: failed to load sysfs info for %s\n", | |
244 | container->devname); | |
245 | exit(3); | |
246 | } | |
247 | if (mdi->array.level != UnSet) { | |
248 | fprintf(stderr, "mdmon: %s is not a container - cannot monitor\n", | |
249 | argv[1]); | |
250 | exit(3); | |
251 | } | |
252 | if (mdi->array.major_version != -1 || | |
253 | mdi->array.minor_version != -2) { | |
254 | fprintf(stderr, "mdmon: %s does not use external metadata - cannot monitor\n", | |
255 | argv[1]); | |
256 | exit(3); | |
257 | } | |
258 | ||
259 | container->ss = find_metadata_methods(mdi->text_version); | |
260 | if (container->ss == NULL) { | |
261 | fprintf(stderr, "mdmon: %s uses unknown metadata: %s\n", | |
262 | argv[1], mdi->text_version); | |
263 | exit(3); | |
264 | } | |
265 | ||
266 | container->devs = NULL; | |
267 | for (di = mdi->devs; di; di = di->next) { | |
268 | struct mdinfo *cd = malloc(sizeof(*cd)); | |
269 | cd = di; | |
270 | cd->next = container->devs; | |
271 | container->devs = cd; | |
272 | } | |
273 | sysfs_free(mdi); | |
274 | ||
275 | ||
276 | if (container->ss->load_super(container, mdfd, argv[1])) { | |
277 | fprintf(stderr, "mdmon: Cannot load metadata for %s\n", | |
278 | argv[1]); | |
279 | exit(3); | |
280 | } | |
e0d6609f | 281 | close(mdfd); |
5869a76c | 282 | close(mdfd); |
549e9569 NB |
283 | |
284 | mlockall(MCL_FUTURE); | |
285 | ||
3e70c845 | 286 | if (clone_monitor(container) < 0) { |
549e9569 NB |
287 | fprintf(stderr, "md-manage: failed to start monitor process: %s\n", |
288 | strerror(errno)); | |
289 | exit(2); | |
290 | } | |
291 | ||
292 | do_manager(container); | |
293 | ||
294 | exit(0); | |
295 | } |