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Monitor: improve check_one_sharer() for checking duplicated process
[thirdparty/mdadm.git] / mdopen.c
CommitLineData
b5e64645
NB
1/*
2 * mdadm - manage Linux "md" devices aka RAID arrays.
3 *
6f02172d 4 * Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
b5e64645
NB
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 * Author: Neil Brown
e736b623 22 * Email: <neilb@suse.de>
b5e64645
NB
23 */
24
25#include "mdadm.h"
26#include "md_p.h"
27#include <ctype.h>
28
c4fe2d4f 29void make_parts(char *dev, int cnt)
b5e64645
NB
30{
31 /* make 'cnt' partition devices for 'dev'
c4fe2d4f
N
32 * If dev is a device name we use the
33 * major/minor from dev and add 1..cnt
34 * If it is a symlink, we make similar symlinks.
8d80900b 35 * If dev ends with a digit, we add "p%d" else "%d"
b5e64645
NB
36 * If the name exists, we use it's owner/mode,
37 * else that of dev
38 */
39 struct stat stb;
96ae5973
JS
40 int major_num;
41 int minor_num;
42 int odig;
b5e64645 43 int i;
8f23b0b3 44 int nlen = strlen(dev) + 20;
0eb26465 45 char *name;
b5e64645 46 int dig = isdigit(dev[strlen(dev)-1]);
c1b78589 47 char orig[1001];
c4fe2d4f 48 char sym[1024];
614825ea 49 int err;
b5e64645 50
ca3b6696
N
51 if (cnt == 0)
52 cnt = 4;
c4fe2d4f 53 if (lstat(dev, &stb)!= 0)
b5e64645 54 return;
0eb26465 55
96ae5973
JS
56 if (S_ISBLK(stb.st_mode)) {
57 major_num = major(stb.st_rdev);
58 minor_num = minor(stb.st_rdev);
59 odig = -1;
60 } else if (S_ISLNK(stb.st_mode)) {
c1b78589
JS
61 int len;
62
63 len = readlink(dev, orig, sizeof(orig));
64 if (len < 0 || len >= (int)sizeof(orig))
c4fe2d4f
N
65 return;
66 orig[len] = 0;
67 odig = isdigit(orig[len-1]);
96ae5973
JS
68 major_num = -1;
69 minor_num = -1;
c4fe2d4f 70 } else
96ae5973 71 return;
503975b9 72 name = xmalloc(nlen);
ca3b6696 73 for (i = 1; i <= cnt ; i++) {
b5e64645 74 struct stat stb2;
8f23b0b3 75 snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
ca3b6696 76 if (stat(name, &stb2) == 0) {
96ae5973 77 if (!S_ISBLK(stb2.st_mode) || !S_ISBLK(stb.st_mode))
b5e64645 78 continue;
b440882e 79 if (stb2.st_rdev == makedev(major_num, minor_num+i))
b5e64645
NB
80 continue;
81 unlink(name);
82 } else {
83 stb2 = stb;
84 }
c4fe2d4f
N
85 if (S_ISBLK(stb.st_mode)) {
86 if (mknod(name, S_IFBLK | 0600,
87 makedev(major_num, minor_num+i)))
88 perror("mknod");
89 if (chown(name, stb2.st_uid, stb2.st_gid))
90 perror("chown");
91 if (chmod(name, stb2.st_mode & 07777))
92 perror("chmod");
614825ea 93 err = 0;
c4fe2d4f 94 } else {
e10a79c3 95 snprintf(sym, sizeof(sym), "%s%s%d", orig, odig?"p":"", i);
614825ea 96 err = symlink(sym, name);
c4fe2d4f 97 }
614825ea
DW
98
99 if (err == 0 && stat(name, &stb2) == 0)
100 add_dev(name, &stb2, 0, NULL);
b5e64645 101 }
0eb26465 102 free(name);
b5e64645
NB
103}
104
7105228e
ZL
105int create_named_array(char *devnm)
106{
107 int fd;
108 int n = -1;
109 static const char new_array_file[] = {
110 "/sys/module/md_mod/parameters/new_array"
111 };
112
113 fd = open(new_array_file, O_WRONLY);
114 if (fd < 0 && errno == ENOENT) {
115 if (system("modprobe md_mod") == 0)
116 fd = open(new_array_file, O_WRONLY);
117 }
118 if (fd >= 0) {
119 n = write(fd, devnm, strlen(devnm));
120 close(fd);
121 }
122 if (fd < 0 || n != (int)strlen(devnm)) {
1a874930
KT
123 pr_err("Fail to create %s when using %s, fallback to creation via node\n",
124 devnm, new_array_file);
7105228e
ZL
125 return 0;
126 }
127
128 return 1;
129}
130
b5e64645 131/*
69207ff6
N
132 * We need a new md device to assemble/build/create an array.
133 * 'dev' is a name given us by the user (command line or mdadm.conf)
134 * It might start with /dev or /dev/md any might end with a digit
135 * string.
136 * If it starts with just /dev, it must be /dev/mdX or /dev/md_dX
137 * If it ends with a digit string, then it must be as above, or
138 * 'trustworthy' must be 'METADATA' and the 'dev' must be
139 * /dev/md/'name'NN or 'name'NN
140 * If it doesn't end with a digit string, it must be /dev/md/'name'
141 * or 'name' or must be NULL.
142 * If the digit string is present, it gives the minor number to use
143 * If not, we choose a high, unused minor number.
144 * If the 'dev' is a standard name, it devices whether 'md' or 'mdp'.
145 * else if the name is 'd[0-9]+' then we use mdp
146 * else if trustworthy is 'METADATA' we use md
147 * else the choice depends on 'autof'.
148 * If name is NULL it is assumed to match whatever dev provides.
149 * If both name and dev are NULL, we choose a name 'mdXX' or 'mdpXX'
150 *
151 * If 'name' is given, and 'trustworthy' is 'foreign' and name is not
152 * supported by 'dev', we add a "_%d" suffix based on the minor number
153 * use that.
154 *
ca3b6696 155 * If udev is configured, we create a temporary device, open it, and
69207ff6 156 * unlink it.
eca944fa 157 * If not, we create the /dev/mdXX device, and if name is usable,
69207ff6
N
158 * /dev/md/name
159 * In any case we return /dev/md/name or (if that isn't available)
160 * /dev/mdXX in 'chosen'.
161 *
162 * When we create devices, we use uid/gid/umask from config file.
b5e64645 163 */
69207ff6
N
164
165int create_mddev(char *dev, char *name, int autof, int trustworthy,
cd6cbb08 166 char *chosen, int block_udev)
b5e64645
NB
167{
168 int mdfd;
169 struct stat stb;
69207ff6
N
170 int num = -1;
171 int use_mdp = -1;
8aec876d 172 struct createinfo *ci = conf_get_create_info();
f1ae21c4 173 int parts;
69207ff6 174 char *cname;
bd1fd72e 175 char devname[37];
4dd2df09 176 char devnm[32];
69207ff6 177 char cbuf[400];
cd6cbb08
N
178
179 if (!use_udev())
180 block_udev = 0;
181
69207ff6
N
182 if (chosen == NULL)
183 chosen = cbuf;
184
5bbb4842
NB
185 if (autof == 0)
186 autof = ci->autof;
187
f1ae21c4
NB
188 parts = autof >> 3;
189 autof &= 7;
190
69207ff6
N
191 strcpy(chosen, "/dev/md/");
192 cname = chosen + strlen(chosen);
193
69207ff6 194 if (dev) {
69207ff6
N
195 if (strncmp(dev, "/dev/md/", 8) == 0) {
196 strcpy(cname, dev+8);
197 } else if (strncmp(dev, "/dev/", 5) == 0) {
198 char *e = dev + strlen(dev);
199 while (e > dev && isdigit(e[-1]))
200 e--;
201 if (e[0])
202 num = strtoul(e, NULL, 10);
203 strcpy(cname, dev+5);
204 cname[e-(dev+5)] = 0;
205 /* name *must* be mdXX or md_dXX in this context */
206 if (num < 0 ||
207 (strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) {
7a862a02 208 pr_err("%s is an invalid name for an md device. Try /dev/md/%s\n",
69207ff6 209 dev, dev+5);
f1ae21c4
NB
210 return -1;
211 }
69207ff6
N
212 if (strcmp(cname, "md") == 0)
213 use_mdp = 0;
214 else
215 use_mdp = 1;
11fb4c05
N
216 /* recreate name: /dev/md/0 or /dev/md/d0 */
217 sprintf(cname, "%s%d", use_mdp?"d":"", num);
69207ff6
N
218 } else
219 strcpy(cname, dev);
220
11fb4c05
N
221 /* 'cname' must not contain a slash, and may not be
222 * empty.
69207ff6 223 */
11fb4c05 224 if (strchr(cname, '/') != NULL) {
7a862a02 225 pr_err("%s is an invalid name for an md device.\n", dev);
69207ff6 226 return -1;
f1ae21c4 227 }
11fb4c05 228 if (cname[0] == 0) {
8e5b52cd 229 pr_err("%s is an invalid name for an md device (empty!).\n", dev);
69207ff6 230 return -1;
b5e64645 231 }
11fb4c05
N
232 if (num < 0) {
233 /* If cname is 'N' or 'dN', we get dev number
234 * from there.
235 */
236 char *sp = cname;
237 char *ep;
238 if (cname[0] == 'd')
239 sp++;
4cda8682
JM
240 if (isdigit(sp[0]))
241 num = strtoul(sp, &ep, 10);
242 else
243 ep = sp;
11fb4c05
N
244 if (ep == sp || *ep || num < 0)
245 num = -1;
246 else if (cname[0] == 'd')
247 use_mdp = 1;
248 else
249 use_mdp = 0;
250 }
69207ff6 251 }
f1ae21c4 252
69207ff6
N
253 /* Now determine device number */
254 /* named 'METADATA' cannot use 'mdp'. */
255 if (name && name[0] == 0)
256 name = NULL;
257 if (name && trustworthy == METADATA && use_mdp == 1) {
7a862a02 258 pr_err("%s is not allowed for a %s container. Consider /dev/md%d.\n", dev, name, num);
69207ff6
N
259 return -1;
260 }
261 if (name && trustworthy == METADATA)
262 use_mdp = 0;
263 if (use_mdp == -1) {
264 if (autof == 4 || autof == 6)
265 use_mdp = 1;
f1ae21c4 266 else
69207ff6
N
267 use_mdp = 0;
268 }
269 if (num < 0 && trustworthy == LOCAL && name) {
ca3b6696 270 /* if name is numeric, possibly prefixed by
d7ba0c55 271 * 'md' or '/dev/md', use that for num
bde2c6e2 272 * if it is not already in use */
69207ff6 273 char *ep;
d7ba0c55
N
274 char *n2 = name;
275 if (strncmp(n2, "/dev/", 5) == 0)
276 n2 += 5;
277 if (strncmp(n2, "md", 2) == 0)
278 n2 += 2;
279 if (*n2 == '/')
280 n2++;
281 num = strtoul(n2, &ep, 10);
282 if (ep == n2 || *ep)
69207ff6 283 num = -1;
4dd2df09
N
284 else {
285 sprintf(devnm, "md%s%d", use_mdp ? "_d":"", num);
286 if (mddev_busy(devnm))
287 num = -1;
288 }
69207ff6
N
289 }
290
69207ff6
N
291 if (cname[0] == 0 && name) {
292 /* Need to find a name if we can
293 * We don't completely trust 'name'. Truncate to
294 * reasonable length and remove '/'
8d80900b 295 */
69207ff6 296 char *cp;
f2e55ecc
N
297 struct map_ent *map = NULL;
298 int conflict = 1;
299 int unum = 0;
300 int cnlen;
69207ff6
N
301 strncpy(cname, name, 200);
302 cname[200] = 0;
7103b9b8
N
303 for (cp = cname; *cp ; cp++)
304 switch (*cp) {
305 case '/':
306 *cp = '-';
307 break;
308 case ' ':
309 case '\t':
310 *cp = '_';
311 break;
312 }
313
f2e55ecc
N
314 if (trustworthy == LOCAL ||
315 (trustworthy == FOREIGN && strchr(cname, ':') != NULL)) {
316 /* Only need suffix if there is a conflict */
317 if (map_by_name(&map, cname) == NULL)
318 conflict = 0;
319 }
320 cnlen = strlen(cname);
321 while (conflict) {
add394f3 322 if (trustworthy == METADATA && !isdigit(cname[cnlen-1]))
f2e55ecc
N
323 sprintf(cname+cnlen, "%d", unum);
324 else
ca3b6696 325 /* add _%d to FOREIGN array that don't
f2e55ecc
N
326 * a 'host:' prefix
327 */
328 sprintf(cname+cnlen, "_%d", unum);
329 unum++;
330 if (map_by_name(&map, cname) == NULL)
331 conflict = 0;
332 }
69207ff6 333 }
9a40c327 334
eca944fa
N
335 devnm[0] = 0;
336 if (num < 0 && cname && ci->names) {
eca944fa 337 sprintf(devnm, "md_%s", cname);
cd6cbb08
N
338 if (block_udev)
339 udev_block(devnm);
7105228e 340 if (!create_named_array(devnm)) {
eca944fa 341 devnm[0] = 0;
cd6cbb08
N
342 udev_unblock();
343 }
eca944fa 344 }
039df362 345 if (num >= 0) {
039df362 346 sprintf(devnm, "md%d", num);
cd6cbb08
N
347 if (block_udev)
348 udev_block(devnm);
7105228e 349 if (!create_named_array(devnm)) {
039df362 350 devnm[0] = 0;
cd6cbb08 351 udev_unblock();
eca944fa 352 }
cd6cbb08
N
353 }
354 if (devnm[0] == 0) {
355 if (num < 0) {
356 /* need to choose a free number. */
357 char *_devnm = find_free_devnm(use_mdp);
358 if (_devnm == NULL) {
359 pr_err("No avail md devices - aborting\n");
360 return -1;
361 }
362 strcpy(devnm, _devnm);
363 } else {
364 sprintf(devnm, "%s%d", use_mdp?"md_d":"md", num);
365 if (mddev_busy(devnm)) {
366 pr_err("%s is already in use.\n",
367 dev);
368 return -1;
369 }
eca944fa 370 }
cd6cbb08
N
371 if (block_udev)
372 udev_block(devnm);
eca944fa
N
373 }
374
375 sprintf(devname, "/dev/%s", devnm);
376
5ac6db12 377 if (dev && dev[0] == '/')
9a40c327
N
378 strcpy(chosen, dev);
379 else if (cname[0] == 0)
69207ff6 380 strcpy(chosen, devname);
8d80900b 381
69207ff6 382 /* We have a device number and name.
11fb4c05
N
383 * If we cannot detect udev, we need to make
384 * devices and links ourselves.
69207ff6 385 */
06d2ffc3 386 if (!use_udev()) {
69207ff6
N
387 /* Make sure 'devname' exists and 'chosen' is a symlink to it */
388 if (lstat(devname, &stb) == 0) {
389 /* Must be the correct device, else error */
390 if ((stb.st_mode&S_IFMT) != S_IFBLK ||
13db17bd 391 stb.st_rdev != devnm2devid(devnm)) {
e7b84f9d 392 pr_err("%s exists but looks wrong, please fix\n",
69207ff6
N
393 devname);
394 return -1;
0a6e1c67 395 }
69207ff6
N
396 } else {
397 if (mknod(devname, S_IFBLK|0600,
4dd2df09 398 devnm2devid(devnm)) != 0) {
e7b84f9d 399 pr_err("failed to create %s\n",
69207ff6 400 devname);
b5e64645
NB
401 return -1;
402 }
69207ff6
N
403 if (chown(devname, ci->uid, ci->gid))
404 perror("chown");
405 if (chmod(devname, ci->mode))
406 perror("chmod");
407 stat(devname, &stb);
408 add_dev(devname, &stb, 0, NULL);
409 }
c4fe2d4f
N
410 if (use_mdp == 1)
411 make_parts(devname, parts);
69207ff6 412
ca3b6696
N
413 if (strcmp(chosen, devname) != 0) {
414 if (mkdir("/dev/md",0700) == 0) {
69207ff6
N
415 if (chown("/dev/md", ci->uid, ci->gid))
416 perror("chown /dev/md");
417 if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
418 perror("chmod /dev/md");
8d80900b 419 }
69207ff6
N
420
421 if (dev && strcmp(chosen, dev) == 0)
422 /* We know we are allowed to use this name */
423 unlink(chosen);
424
425 if (lstat(chosen, &stb) == 0) {
426 char buf[300];
fca13185
TJ
427 ssize_t link_len = readlink(chosen, buf, sizeof(buf)-1);
428 if (link_len >= 0)
429 buf[link_len] = '\0';
430
69207ff6 431 if ((stb.st_mode & S_IFMT) != S_IFLNK ||
fca13185 432 link_len < 0 ||
69207ff6 433 strcmp(buf, devname) != 0) {
e7b84f9d 434 pr_err("%s exists - ignoring\n",
69207ff6
N
435 chosen);
436 strcpy(chosen, devname);
437 }
614825ea 438 } else if (symlink(devname, chosen) != 0)
e7b84f9d 439 pr_err("failed to create %s: %s\n",
614825ea 440 chosen, strerror(errno));
c4fe2d4f
N
441 if (use_mdp && strcmp(chosen, devname) != 0)
442 make_parts(chosen, parts);
b5e64645 443 }
b5e64645 444 }
4dd2df09 445 mdfd = open_dev_excl(devnm);
69207ff6 446 if (mdfd < 0)
e7b84f9d 447 pr_err("unexpected failure opening %s\n",
69207ff6 448 devname);
6be1d39d
N
449 return mdfd;
450}
451
452/* Open this and check that it is an md device.
453 * On success, return filedescriptor.
454 * On failure, return -1 if it doesn't exist,
455 * or -2 if it exists but is not an md device.
456 */
457int open_mddev(char *dev, int report_errors)
458{
f71d2b8f 459 int mdfd = open(dev, O_RDONLY);
40b054e1 460
6be1d39d
N
461 if (mdfd < 0) {
462 if (report_errors)
e7b84f9d 463 pr_err("error opening %s: %s\n",
6be1d39d
N
464 dev, strerror(errno));
465 return -1;
466 }
40b054e1 467
9db2ab4e 468 if (md_array_valid(mdfd) == 0) {
b5e64645 469 close(mdfd);
6be1d39d 470 if (report_errors)
7a862a02 471 pr_err("%s does not appear to be an md device\n", dev);
6be1d39d 472 return -2;
b5e64645 473 }
40b054e1 474
b5e64645
NB
475 return mdfd;
476}
289c74f8
N
477
478char *find_free_devnm(int use_partitions)
479{
480 static char devnm[32];
481 int devnum;
482 for (devnum = 127; devnum != 128;
2e466cce 483 devnum = devnum ? devnum-1 : (1<<9)-1) {
289c74f8
N
484
485 if (use_partitions)
486 sprintf(devnm, "md_d%d", devnum);
487 else
488 sprintf(devnm, "md%d", devnum);
489 if (mddev_busy(devnm))
490 continue;
491 if (!conf_name_is_free(devnm))
492 continue;
493 if (!use_udev()) {
494 /* make sure it is new to /dev too, at least as a
495 * non-standard */
13db17bd 496 dev_t devid = devnm2devid(devnm);
289c74f8
N
497 if (devid) {
498 char *dn = map_dev(major(devid),
499 minor(devid), 0);
500 if (dn && ! is_standard(dn, NULL))
501 continue;
502 }
503 }
504 break;
505 }
506 if (devnum == 128)
507 return NULL;
508 return devnm;
509}