summaryrefslogtreecommitdiff
path: root/mdstat.c
blob: 2fd792c5d56de1ce4547efd3a3c2fcd71ab96a87 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
/*
 * mdstat - parse /proc/mdstat file. Part of:
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2002-2009 Neil Brown <neilb@suse.de>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *    Author: Neil Brown
 *    Email: <neilb@suse.de>
 */

/*
 * The /proc/mdstat file comes in at least 3 flavours:
 * In an unpatched 2.2 kernel (md 0.36.6):
 *  Personalities : [n raidx] ...
 *  read_ahead {not set|%d sectors}
 *  md0 : {in}active{ raidX /dev/hda...  %d blocks{ maxfault=%d}}
 *  md1 : .....
 *
 * Normally only 4 md lines, but all are listed.
 *
 * In a patched 2.2 kernel (md 0.90.0)
 *  Personalities : [raidx] ...
 *  read_ahead {not set|%d sectors}
 *  mdN : {in}active {(readonly)} raidX dev[%d]{(F)} ... %d blocks STATUS RESYNC
 *  ... Only initialised arrays listed
 *  unused devices: {dev dev ... | <none>}
 *
 * STATUS is personality dependant:
 *    linear:  %dk rounding
 *    raid0:   %dk chunks
 *    raid1:   [%d/%d] [U_U]   ( raid/working.  operational or not)
 *    raid5:   level 4/5, %dk chunk, algorithm %d [%d/%d] [U_U]
 *
 * RESYNC is  empty or:
 *    {resync|recovery}=%u%% finish=%u.%umin
 *  or
 *    resync=DELAYED
 *
 * In a 2.4 kernel (md 0.90.0/2.4)
 *  Personalities : [raidX] ...
 *  read_ahead {not set|%d sectors}
 *  mdN : {in}active {(read-only)} raidX dev[%d]{(F)} ...
 *       %d blocks STATUS
 *       RESYNC
 *  unused devices: {dev dev .. | <none>}
 *
 *  STATUS matches 0.90.0/2.2
 *  RESYNC includes [===>....],
 *          adds a space after {resync|recovery} and before and after '='
 *          adds a decimal to the recovery percent.
 *	    adds (%d/%d) resync amount  and max_blocks, before finish.
 *	    adds speed=%dK/sec after finish
 *
 *
 *
 * Out of this we want to extract:
 *   list of devices, active or not
 *   pattern of failed drives (so need number of drives)
 *   percent resync complete
 *
 * As continuation is indicated by leading space, we use
 *  conf_line from config.c to read logical lines
 *
 */

#include	"mdadm.h"
#include	"dlink.h"
#include	<sys/select.h>
#include	<ctype.h>

static void free_member_devnames(struct dev_member *m)
{
	while(m) {
		struct dev_member *t = m;

		m = m->next;
		free(t->name);
		free(t);
	}
}

static int add_member_devname(struct dev_member **m, char *name)
{
	struct dev_member *new;
	char *t;

	if ((t = strchr(name, '[')) == NULL)
		/* not a device */
		return 0;

	new = xmalloc(sizeof(*new));
	new->name = strndup(name, t - name);
	new->next = *m;
	*m = new;
	return 1;
}

void free_mdstat(struct mdstat_ent *ms)
{
	while (ms) {
		struct mdstat_ent *t;
		free(ms->level);
		free(ms->pattern);
		free(ms->metadata_version);
		free_member_devnames(ms->members);
		t = ms;
		ms = ms->next;
		free(t);
	}
}

static int mdstat_fd = -1;
struct mdstat_ent *mdstat_read(int hold, int start)
{
	FILE *f;
	struct mdstat_ent *all, *rv, **end, **insert_here;
	char *line;
	int fd;

	if (hold && mdstat_fd != -1) {
		off_t offset = lseek(mdstat_fd, 0L, 0);
		if (offset == (off_t)-1) {
			return NULL;
		}
		fd = dup(mdstat_fd);
		if (fd >= 0)
			f = fdopen(fd, "r");
		else
			return NULL;
	} else
		f = fopen("/proc/mdstat", "r");
	if (f == NULL)
		return NULL;
	else
		fcntl(fileno(f), F_SETFD, FD_CLOEXEC);

	all = NULL;
	end = &all;
	for (; (line = conf_line(f)) ; free_line(line)) {
		struct mdstat_ent *ent;
		char *w;
		char devnm[32];
		int in_devs = 0;

		if (strcmp(line, "Personalities") == 0)
			continue;
		if (strcmp(line, "read_ahead") == 0)
			continue;
		if (strcmp(line, "unused") == 0)
			continue;
		insert_here = NULL;
		/* Better be an md line.. */
		if (strncmp(line, "md", 2)!= 0 || strlen(line) >= 32 ||
		    (line[2] != '_' && !isdigit(line[2])))
			continue;
		strcpy(devnm, line);

		ent = xmalloc(sizeof(*ent));
		ent->level = ent->pattern= NULL;
		ent->next = NULL;
		ent->percent = RESYNC_NONE;
		ent->active = -1;
		ent->resync = 0;
		ent->metadata_version = NULL;
		ent->raid_disks = 0;
		ent->devcnt = 0;
		ent->members = NULL;

		strcpy(ent->devnm, devnm);

		for (w=dl_next(line); w!= line ; w=dl_next(w)) {
			int l = strlen(w);
			char *eq;
			if (strcmp(w, "active") == 0)
				ent->active = 1;
			else if (strcmp(w, "inactive") == 0) {
				ent->active = 0;
				in_devs = 1;
			} else if (strcmp(w, "bitmap:") == 0) {
				/* We need to stop parsing here;
				 * otherwise, ent->raid_disks will be
				 * overwritten by the wrong value.
				 */
				break;
			} else if (ent->active > 0 &&
				 ent->level == NULL &&
				 w[0] != '(' /*readonly*/) {
				ent->level = xstrdup(w);
				in_devs = 1;
			} else if (in_devs && strcmp(w, "blocks") == 0)
				in_devs = 0;
			else if (in_devs) {
				char *ep = strchr(w, '[');
				ent->devcnt +=
					add_member_devname(&ent->members, w);
				if (ep && strncmp(w, "md", 2) == 0) {
					/* This has an md device as a component.
					 * If that device is already in the
					 * list, make sure we insert before
					 * there.
					 */
					struct mdstat_ent **ih;
					ih = &all;
					while (ih != insert_here && *ih &&
					       ((int)strlen((*ih)->devnm) !=
						ep-w ||
						strncmp((*ih)->devnm, w,
							ep-w) != 0))
						ih = & (*ih)->next;
					insert_here = ih;
				}
			} else if (strcmp(w, "super") == 0 &&
				   dl_next(w) != line) {
				w = dl_next(w);
				ent->metadata_version = xstrdup(w);
			} else if (w[0] == '[' && isdigit(w[1])) {
				ent->raid_disks = atoi(w+1);
			} else if (!ent->pattern &&
				   w[0] == '[' &&
				   (w[1] == 'U' || w[1] == '_')) {
				ent->pattern = xstrdup(w+1);
				if (ent->pattern[l-2] == ']')
					ent->pattern[l-2] = '\0';
			} else if (ent->percent == RESYNC_NONE &&
				   strncmp(w, "re", 2) == 0 &&
				   w[l-1] == '%' &&
				   (eq = strchr(w, '=')) != NULL ) {
				ent->percent = atoi(eq+1);
				if (strncmp(w,"resync", 6) == 0)
					ent->resync = 1;
				else if (strncmp(w, "reshape", 7) == 0)
					ent->resync = 2;
				else
					ent->resync = 0;
			} else if (ent->percent == RESYNC_NONE &&
				   (w[0] == 'r' || w[0] == 'c')) {
				if (strncmp(w, "resync", 6) == 0)
					ent->resync = 1;
				if (strncmp(w, "reshape", 7) == 0)
					ent->resync = 2;
				if (strncmp(w, "recovery", 8) == 0)
					ent->resync = 0;
				if (strncmp(w, "check", 5) == 0)
					ent->resync = 3;

				if (l > 8 && strcmp(w+l-8, "=DELAYED") == 0)
					ent->percent = RESYNC_DELAYED;
				if (l > 8 && strcmp(w+l-8, "=PENDING") == 0)
					ent->percent = RESYNC_PENDING;
				if (l > 7 && strcmp(w+l-7, "=REMOTE") == 0)
					ent->percent = RESYNC_REMOTE;
			} else if (ent->percent == RESYNC_NONE &&
				   w[0] >= '0' &&
				   w[0] <= '9' &&
				   w[l-1] == '%') {
				ent->percent = atoi(w);
			}
		}
		if (insert_here && (*insert_here)) {
			ent->next = *insert_here;
			*insert_here = ent;
		} else {
			*end = ent;
			end = &ent->next;
		}
	}
	if (hold && mdstat_fd == -1) {
		mdstat_fd = dup(fileno(f));
		fcntl(mdstat_fd, F_SETFD, FD_CLOEXEC);
	}
	fclose(f);

	/* If we might want to start array,
	 * reverse the order, so that components comes before composites
	 */
	if (start) {
		rv = NULL;
		while (all) {
			struct mdstat_ent *e = all;
			all = all->next;
			e->next = rv;
			rv = e;
		}
	} else
		rv = all;
	return rv;
}

void mdstat_close(void)
{
	if (mdstat_fd >= 0)
		close(mdstat_fd);
	mdstat_fd = -1;
}

/*
 * function: mdstat_wait
 * Description: Function waits for event on mdstat.
 * Parameters:
 *		seconds - timeout for waiting
 * Returns:
 *		> 0 - detected event
 *		0 - timeout
 *		< 0 - detected error
 */
int mdstat_wait(int seconds)
{
	fd_set fds;
	struct timeval tm;
	int maxfd = 0;
	FD_ZERO(&fds);
	if (mdstat_fd >= 0) {
		FD_SET(mdstat_fd, &fds);
		maxfd = mdstat_fd;
	} else
		return -1;

	tm.tv_sec = seconds;
	tm.tv_usec = 0;

	return select(maxfd + 1, NULL, NULL, &fds, &tm);
}

void mdstat_wait_fd(int fd, const sigset_t *sigmask)
{
	fd_set fds, rfds;
	int maxfd = 0;

	FD_ZERO(&fds);
	FD_ZERO(&rfds);
	if (mdstat_fd >= 0)
		FD_SET(mdstat_fd, &fds);

	if (fd >= 0) {
		struct stat stb;
		fstat(fd, &stb);
		if ((stb.st_mode & S_IFMT) == S_IFREG)
			/* Must be a /proc or /sys fd, so expect
			 * POLLPRI
			 * i.e. an 'exceptional' event.
			 */
			FD_SET(fd, &fds);
		else
			FD_SET(fd, &rfds);

		if (fd > maxfd)
			maxfd = fd;

	}
	if (mdstat_fd > maxfd)
		maxfd = mdstat_fd;

	pselect(maxfd + 1, &rfds, NULL, &fds,
		NULL, sigmask);
}

int mddev_busy(char *devnm)
{
	struct mdstat_ent *mdstat = mdstat_read(0, 0);
	struct mdstat_ent *me;

	for (me = mdstat ; me ; me = me->next)
		if (strcmp(me->devnm, devnm) == 0)
			break;
	free_mdstat(mdstat);
	return me != NULL;
}

struct mdstat_ent *mdstat_by_component(char *name)
{
	struct mdstat_ent *mdstat = mdstat_read(0, 0);

	while (mdstat) {
		struct dev_member *m;
		struct mdstat_ent *ent;
		if (mdstat->metadata_version &&
		    strncmp(mdstat->metadata_version, "external:", 9) == 0 &&
		    is_subarray(mdstat->metadata_version+9))
			/* don't return subarrays, only containers */
			;
		else for (m = mdstat->members; m; m = m->next) {
				if (strcmp(m->name, name) == 0) {
					free_mdstat(mdstat->next);
					mdstat->next = NULL;
					return mdstat;
				}
			}
		ent = mdstat;
		mdstat = mdstat->next;
		ent->next = NULL;
		free_mdstat(ent);
	}
	return NULL;
}

struct mdstat_ent *mdstat_by_subdev(char *subdev, char *container)
{
	struct mdstat_ent *mdstat = mdstat_read(0, 0);
	struct mdstat_ent *ent = NULL;

	while (mdstat) {
		/* metadata version must match:
		 *   external:[/-]%s/%s
		 * where first %s is 'container' and second %s is 'subdev'
		 */
		if (ent)
			free_mdstat(ent);
		ent = mdstat;
		mdstat = mdstat->next;
		ent->next = NULL;

		if (ent->metadata_version == NULL ||
		    strncmp(ent->metadata_version, "external:", 9) != 0)
			continue;

		if (!metadata_container_matches(ent->metadata_version+9,
					       container) ||
		    !metadata_subdev_matches(ent->metadata_version+9,
					     subdev))
			continue;

		free_mdstat(mdstat);
		return ent;
	}
	return NULL;
}