summaryrefslogtreecommitdiffstats
path: root/sysfs.c
blob: 37b8b0974a142121be5ba6d9f7556dac33376427 (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
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
/*
 * sysfs - extract md related information from sysfs.  Part of:
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2006 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>
 */

#include	"mdadm.h"
#include	<dirent.h>

int load_sys(char *path, char *buf)
{
	int fd = open(path, O_RDONLY);
	int n;
	if (fd < 0)
		return -1;
	n = read(fd, buf, 1024);
	close(fd);
	if (n <0 || n >= 1024)
		return -1;
	buf[n] = 0;
	if (buf[n-1] == '\n')
		buf[n-1] = 0;
	return 0;
}

void sysfs_free(struct mdinfo *sra)
{
	while (sra) {
		struct mdinfo *sra2 = sra->next;
		while (sra->devs) {
			struct mdinfo *d = sra->devs;
			sra->devs = d->next;
			free(d);
		}
		free(sra);
		sra = sra2;
	}
}

int sysfs_open(int devnum, char *devname, char *attr)
{
	char fname[50];
	char sys_name[16];
	int fd;
	if (devnum >= 0)
		sprintf(sys_name, "md%d", devnum);
	else
		sprintf(sys_name, "md_d%d",
			-1-devnum);

	sprintf(fname, "/sys/block/%s/md/", sys_name);
	if (devname) {
		strcat(fname, devname);
		strcat(fname, "/");
	}
	strcat(fname, attr);
	fd = open(fname, O_RDWR);
	if (fd < 0 && errno == EACCES)
		fd = open(fname, O_RDONLY);
	return fd;
}

struct mdinfo *sysfs_read(int fd, int devnum, unsigned long options)
{
	/* Longest possible name in sysfs, mounted at /sys, is
	 *  /sys/block/md_dXXX/md/dev-XXXXX/block/dev
	 *  /sys/block/md_dXXX/md/metadata_version
	 * which is about 41 characters.  50 should do for now
	 */
	char fname[50];
	char buf[1024];
	char *base;
	char *dbase;
	struct mdinfo *sra;
	struct mdinfo *dev;
	DIR *dir = NULL;
	struct dirent *de;

	sra = malloc(sizeof(*sra));
	if (sra == NULL)
		return sra;
	sra->next = NULL;

	if (fd >= 0) {
		struct stat stb;
		mdu_version_t vers;
 		if (fstat(fd, &stb)) return NULL;
		if (ioctl(fd, RAID_VERSION, &vers) != 0)
			return NULL;
		if (major(stb.st_rdev)==9)
			sprintf(sra->sys_name, "md%d", (int)minor(stb.st_rdev));
		else
			sprintf(sra->sys_name, "md_d%d",
				(int)minor(stb.st_rdev)>>MdpMinorShift);
	} else {
		if (devnum >= 0)
			sprintf(sra->sys_name, "md%d", devnum);
		else
			sprintf(sra->sys_name, "md_d%d",
				-1-devnum);
	}
	sprintf(fname, "/sys/block/%s/md/", sra->sys_name);
	base = fname + strlen(fname);

	sra->devs = NULL;
	if (options & GET_VERSION) {
		strcpy(base, "metadata_version");
		if (load_sys(fname, buf))
			goto abort;
		if (strncmp(buf, "none", 4) == 0) {
			sra->array.major_version =
				sra->array.minor_version = -1;
			strcpy(sra->text_version, "");
		} else if (strncmp(buf, "external:", 9) == 0) {
			sra->array.major_version = -1;
			sra->array.minor_version = -2;
			strcpy(sra->text_version, buf+9);
		} else
			sscanf(buf, "%d.%d",
			       &sra->array.major_version,
			       &sra->array.minor_version);
	}
	if (options & GET_LEVEL) {
		strcpy(base, "level");
		if (load_sys(fname, buf))
			goto abort;
		sra->array.level = map_name(pers, buf);
	}
	if (options & GET_LAYOUT) {
		strcpy(base, "layout");
		if (load_sys(fname, buf))
			goto abort;
		sra->array.layout = strtoul(buf, NULL, 0);
	}
	if (options & GET_DISKS) {
		strcpy(base, "raid_disks");
		if (load_sys(fname, buf))
			goto abort;
		sra->array.raid_disks = strtoul(buf, NULL, 0);
	}
	if (options & GET_COMPONENT) {
		strcpy(base, "component_size");
		if (load_sys(fname, buf))
			goto abort;
		sra->component_size = strtoull(buf, NULL, 0);
		/* sysfs reports "K", but we want sectors */
		sra->component_size *= 2;
	}
	if (options & GET_CHUNK) {
		strcpy(base, "chunk_size");
		if (load_sys(fname, buf))
			goto abort;
		sra->array.chunk_size = strtoul(buf, NULL, 0);
	}
	if (options & GET_CACHE) {
		strcpy(base, "stripe_cache_size");
		if (load_sys(fname, buf))
			goto abort;
		sra->cache_size = strtoul(buf, NULL, 0);
	}
	if (options & GET_MISMATCH) {
		strcpy(base, "mismatch_cnt");
		if (load_sys(fname, buf))
			goto abort;
		sra->mismatch_cnt = strtoul(buf, NULL, 0);
	}

	if (! (options & GET_DEVS))
		return sra;

	/* Get all the devices as well */
	*base = 0;
	dir = opendir(fname);
	if (!dir)
		goto abort;
	sra->array.spare_disks = 0;

	while ((de = readdir(dir)) != NULL) {
		char *ep;
		if (de->d_ino == 0 ||
		    strncmp(de->d_name, "dev-", 4) != 0)
			continue;
		strcpy(base, de->d_name);
		dbase = base + strlen(base);
		*dbase++ = '/';

		dev = malloc(sizeof(*dev));
		if (!dev)
			goto abort;
		dev->next = sra->devs;
		sra->devs = dev;
		strcpy(dev->sys_name, de->d_name);

		/* Always get slot, major, minor */
		strcpy(dbase, "slot");
		if (load_sys(fname, buf))
			goto abort;
		dev->disk.raid_disk = strtoul(buf, &ep, 10);
		if (*ep) dev->disk.raid_disk = -1;

		strcpy(dbase, "block/dev");
		if (load_sys(fname, buf))
			goto abort;
		sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);

		if (options & GET_OFFSET) {
			strcpy(dbase, "offset");
			if (load_sys(fname, buf))
				goto abort;
			dev->data_offset = strtoull(buf, NULL, 0);
		}
		if (options & GET_SIZE) {
			strcpy(dbase, "size");
			if (load_sys(fname, buf))
				goto abort;
			dev->component_size = strtoull(buf, NULL, 0);
		}
		if (options & GET_STATE) {
			dev->disk.state = 0;
			strcpy(dbase, "state");
			if (load_sys(fname, buf))
				goto abort;
			if (strstr(buf, "in_sync"))
				dev->disk.state |= (1<<MD_DISK_SYNC);
			if (strstr(buf, "faulty"))
				dev->disk.state |= (1<<MD_DISK_FAULTY);
			if (dev->disk.state == 0)
				sra->array.spare_disks++;
		}
		if (options & GET_ERROR) {
			strcpy(buf, "errors");
			if (load_sys(fname, buf))
				goto abort;
			dev->errors = strtoul(buf, NULL, 0);
		}
	}
	closedir(dir);
	return sra;

 abort:
	if (dir)
		closedir(dir);
	sysfs_free(sra);
	return NULL;
}

unsigned long long get_component_size(int fd)
{
	/* Find out the component size of the array.
	 * We cannot trust GET_ARRAY_INFO ioctl as it's
	 * size field is only 32bits.
	 * So look in /sys/block/mdXXX/md/component_size
	 *
	 * This returns in units of sectors.
	 */
	struct stat stb;
	char fname[50];
	int n;
	if (fstat(fd, &stb)) return 0;
	if (major(stb.st_rdev) == 9)
		sprintf(fname, "/sys/block/md%d/md/component_size",
			(int)minor(stb.st_rdev));
	else
		sprintf(fname, "/sys/block/md_d%d/md/component_size",
			(int)minor(stb.st_rdev)>>MdpMinorShift);
	fd = open(fname, O_RDONLY);
	if (fd < 0)
		return 0;
	n = read(fd, fname, sizeof(fname));
	close(fd);
	if (n == sizeof(fname))
		return 0;
	fname[n] = 0;
	return strtoull(fname, NULL, 10) * 2;
}

int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
		  char *name, char *val)
{
	char fname[50];
	int n;
	int fd;

	sprintf(fname, "/sys/block/%s/md/%s/%s",
		sra->sys_name, dev?dev->sys_name:"", name);
	fd = open(fname, O_WRONLY);
	if (fd < 0)
		return -1;
	n = write(fd, val, strlen(val));
	close(fd);
	if (n != strlen(val))
		return -1;
	return 0;
}

int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
		  char *name, unsigned long long val)
{
	char valstr[50];
	sprintf(valstr, "%llu", val);
	return sysfs_set_str(sra, dev, name, valstr);
}

int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
		       char *name, unsigned long long *val)
{
	char fname[50];
	char buf[50];
	int n;
	int fd;
	char *ep;
	sprintf(fname, "/sys/block/%s/md/%s/%s",
		sra->sys_name, dev?dev->sys_name:"", name);
	fd = open(fname, O_RDONLY);
	if (fd < 0)
		return -1;
	n = read(fd, buf, sizeof(buf));
	close(fd);
	if (n <= 0)
		return -1;
	buf[n] = 0;
	*val = strtoull(buf, &ep, 0);
	if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
		return -1;
	return 0;
}

int sysfs_set_array(struct mdinfo *sra,
		    struct mdinfo *info)
{
	int rv = 0;
	sra->array = info->array;

	if (info->array.level < 0)
		return 0; /* FIXME */
	rv |= sysfs_set_str(sra, NULL, "level",
			    map_num(pers, info->array.level));
	rv |= sysfs_set_num(sra, NULL, "raid_disks", info->array.raid_disks);
	rv |= sysfs_set_num(sra, NULL, "chunk_size", info->array.chunk_size);
	rv |= sysfs_set_num(sra, NULL, "layout", info->array.layout);
	rv |= sysfs_set_num(sra, NULL, "component_size", info->component_size);
	rv |= sysfs_set_num(sra, NULL, "resync_start", info->resync_start);
	sra->array = info->array;
	return rv;
}

int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd)
{
	char dv[100];
	char nm[100];
	struct mdinfo *sd2;
	char *dname;
	int rv;

	sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
	rv = sysfs_set_str(sra, NULL, "new_dev", dv);
	if (rv)
		return rv;

	memset(nm, 0, sizeof(nm));
	sprintf(dv, "/sys/dev/block/%d:%d", sd->disk.major, sd->disk.minor);
	if (readlink(dv, nm, sizeof(nm)) < 0)
		return -1;
	dname = strrchr(nm, '/');
	if (dname) dname++;
	strcpy(sd->sys_name, "dev-");
	strcpy(sd->sys_name+4, dname);

	rv |= sysfs_set_num(sra, sd, "offset", sd->data_offset);
	rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
	if (sra->array.level != LEVEL_CONTAINER) {
		rv |= sysfs_set_num(sra, sd, "slot", sd->disk.raid_disk);
//		rv |= sysfs_set_str(sra, sd, "state", "in_sync");
	}
	if (! rv) {
		sd2 = malloc(sizeof(*sd2));
		*sd2 = *sd;
		sd2->next = sra->devs;
		sra->devs = sd2;
	}
	return rv;
}

int sysfs_disk_to_sg(int fd)
{
	/* from an open block device, try find and open its corresponding
	 * scsi_generic interface
	 */
	struct stat st;
	char path[256];
	char sg_path[256];
	char sg_major_minor[8];
	char *c;
	DIR *dir;
	struct dirent *de;
	int major, minor, rv;

	if (fstat(fd, &st))
		return -1;

	snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device",
		 major(st.st_rdev), minor(st.st_rdev));

	dir = opendir(path);
	if (!dir)
		return -1;

	de = readdir(dir);
	while (de) {
		if (strncmp("scsi_generic:", de->d_name,
			    strlen("scsi_generic:")) == 0)
			break;
		de = readdir(dir);
	}
	closedir(dir);

	if (!de)
		return -1;

	snprintf(sg_path, sizeof(sg_path), "%s/%s/dev", path, de->d_name);
	fd = open(sg_path, O_RDONLY);
	if (fd < 0)
		return fd;

	rv = read(fd, sg_major_minor, sizeof(sg_major_minor));
	close(fd);
	if (rv < 0)
		return -1;
	else
		sg_major_minor[rv - 1] = '\0';

	c = strchr(sg_major_minor, ':');
	*c = '\0';
	c++;
	major = strtol(sg_major_minor, NULL, 10);
	minor = strtol(c, NULL, 10);
	snprintf(path, sizeof(path), "/dev/.tmp.md.%d:%d:%d",
		 (int) getpid(), major, minor);
	if (mknod(path, S_IFCHR|0600, makedev(major, minor))==0) {
			fd = open(path, O_RDONLY);
			unlink(path);
			return fd;
	}

	return -1;
}