]> git.ipfire.org Git - thirdparty/mdadm.git/blob - mdopen.c
DDF: compare_super_ddf: merge local info of other superblock
[thirdparty/mdadm.git] / mdopen.c
1 /*
2 * mdadm - manage Linux "md" devices aka RAID arrays.
3 *
4 * Copyright (C) 2001-2012 Neil Brown <neilb@suse.de>
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
22 * Email: <neilb@suse.de>
23 */
24
25 #include "mdadm.h"
26 #include "md_p.h"
27 #include <ctype.h>
28
29 void make_parts(char *dev, int cnt)
30 {
31 /* make 'cnt' partition devices for 'dev'
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.
35 * If dev ends with a digit, we add "p%d" else "%d"
36 * If the name exists, we use it's owner/mode,
37 * else that of dev
38 */
39 struct stat stb;
40 int major_num;
41 int minor_num;
42 int odig;
43 int i;
44 int nlen = strlen(dev) + 20;
45 char *name;
46 int dig = isdigit(dev[strlen(dev)-1]);
47 char orig[1024];
48 char sym[1024];
49 int err;
50
51 if (cnt == 0)
52 cnt = 4;
53 if (lstat(dev, &stb)!= 0)
54 return;
55
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)) {
61 int len = readlink(dev, orig, sizeof(orig));
62 if (len < 0 || len > 1000)
63 return;
64 orig[len] = 0;
65 odig = isdigit(orig[len-1]);
66 major_num = -1;
67 minor_num = -1;
68 } else
69 return;
70 name = xmalloc(nlen);
71 for (i = 1; i <= cnt ; i++) {
72 struct stat stb2;
73 snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
74 if (stat(name, &stb2) == 0) {
75 if (!S_ISBLK(stb2.st_mode) || !S_ISBLK(stb.st_mode))
76 continue;
77 if (stb2.st_rdev == makedev(major_num, minor_num+i))
78 continue;
79 unlink(name);
80 } else {
81 stb2 = stb;
82 }
83 if (S_ISBLK(stb.st_mode)) {
84 if (mknod(name, S_IFBLK | 0600,
85 makedev(major_num, minor_num+i)))
86 perror("mknod");
87 if (chown(name, stb2.st_uid, stb2.st_gid))
88 perror("chown");
89 if (chmod(name, stb2.st_mode & 07777))
90 perror("chmod");
91 err = 0;
92 } else {
93 snprintf(sym, sizeof(sym), "%s%s%d", orig, odig?"p":"", i);
94 err = symlink(sym, name);
95 }
96
97 if (err == 0 && stat(name, &stb2) == 0)
98 add_dev(name, &stb2, 0, NULL);
99 }
100 free(name);
101 }
102
103 /*
104 * We need a new md device to assemble/build/create an array.
105 * 'dev' is a name given us by the user (command line or mdadm.conf)
106 * It might start with /dev or /dev/md any might end with a digit
107 * string.
108 * If it starts with just /dev, it must be /dev/mdX or /dev/md_dX
109 * If it ends with a digit string, then it must be as above, or
110 * 'trustworthy' must be 'METADATA' and the 'dev' must be
111 * /dev/md/'name'NN or 'name'NN
112 * If it doesn't end with a digit string, it must be /dev/md/'name'
113 * or 'name' or must be NULL.
114 * If the digit string is present, it gives the minor number to use
115 * If not, we choose a high, unused minor number.
116 * If the 'dev' is a standard name, it devices whether 'md' or 'mdp'.
117 * else if the name is 'd[0-9]+' then we use mdp
118 * else if trustworthy is 'METADATA' we use md
119 * else the choice depends on 'autof'.
120 * If name is NULL it is assumed to match whatever dev provides.
121 * If both name and dev are NULL, we choose a name 'mdXX' or 'mdpXX'
122 *
123 * If 'name' is given, and 'trustworthy' is 'foreign' and name is not
124 * supported by 'dev', we add a "_%d" suffix based on the minor number
125 * use that.
126 *
127 * If udev is configured, we create a temporary device, open it, and
128 * unlink it.
129 * If not, we create the /dev/mdXX device, and is name is usable,
130 * /dev/md/name
131 * In any case we return /dev/md/name or (if that isn't available)
132 * /dev/mdXX in 'chosen'.
133 *
134 * When we create devices, we use uid/gid/umask from config file.
135 */
136
137 int create_mddev(char *dev, char *name, int autof, int trustworthy,
138 char *chosen)
139 {
140 int mdfd;
141 struct stat stb;
142 int num = -1;
143 int use_mdp = -1;
144 struct createinfo *ci = conf_get_create_info();
145 int parts;
146 char *cname;
147 char devname[20];
148 char devnm[32];
149 char cbuf[400];
150 if (chosen == NULL)
151 chosen = cbuf;
152
153 if (autof == 0)
154 autof = ci->autof;
155
156 parts = autof >> 3;
157 autof &= 7;
158
159 strcpy(chosen, "/dev/md/");
160 cname = chosen + strlen(chosen);
161
162 if (dev) {
163 if (strncmp(dev, "/dev/md/", 8) == 0) {
164 strcpy(cname, dev+8);
165 } else if (strncmp(dev, "/dev/", 5) == 0) {
166 char *e = dev + strlen(dev);
167 while (e > dev && isdigit(e[-1]))
168 e--;
169 if (e[0])
170 num = strtoul(e, NULL, 10);
171 strcpy(cname, dev+5);
172 cname[e-(dev+5)] = 0;
173 /* name *must* be mdXX or md_dXX in this context */
174 if (num < 0 ||
175 (strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) {
176 pr_err("%s is an invalid name "
177 "for an md device. Try /dev/md/%s\n",
178 dev, dev+5);
179 return -1;
180 }
181 if (strcmp(cname, "md") == 0)
182 use_mdp = 0;
183 else
184 use_mdp = 1;
185 /* recreate name: /dev/md/0 or /dev/md/d0 */
186 sprintf(cname, "%s%d", use_mdp?"d":"", num);
187 } else
188 strcpy(cname, dev);
189
190 /* 'cname' must not contain a slash, and may not be
191 * empty.
192 */
193 if (strchr(cname, '/') != NULL) {
194 pr_err("%s is an invalid name "
195 "for an md device.\n", dev);
196 return -1;
197 }
198 if (cname[0] == 0) {
199 pr_err("%s is an invalid name "
200 "for an md device (empty!).", dev);
201 return -1;
202 }
203 if (num < 0) {
204 /* If cname is 'N' or 'dN', we get dev number
205 * from there.
206 */
207 char *sp = cname;
208 char *ep;
209 if (cname[0] == 'd')
210 sp++;
211 if (isdigit(sp[0]))
212 num = strtoul(sp, &ep, 10);
213 else
214 ep = sp;
215 if (ep == sp || *ep || num < 0)
216 num = -1;
217 else if (cname[0] == 'd')
218 use_mdp = 1;
219 else
220 use_mdp = 0;
221 }
222 }
223
224 /* Now determine device number */
225 /* named 'METADATA' cannot use 'mdp'. */
226 if (name && name[0] == 0)
227 name = NULL;
228 if (name && trustworthy == METADATA && use_mdp == 1) {
229 pr_err("%s is not allowed for a %s container. "
230 "Consider /dev/md%d.\n", dev, name, num);
231 return -1;
232 }
233 if (name && trustworthy == METADATA)
234 use_mdp = 0;
235 if (use_mdp == -1) {
236 if (autof == 4 || autof == 6)
237 use_mdp = 1;
238 else
239 use_mdp = 0;
240 }
241 if (num < 0 && trustworthy == LOCAL && name) {
242 /* if name is numeric, possibly prefixed by
243 * 'md' or '/dev/md', use that for num
244 * if it is not already in use */
245 char *ep;
246 char *n2 = name;
247 if (strncmp(n2, "/dev/", 5) == 0)
248 n2 += 5;
249 if (strncmp(n2, "md", 2) == 0)
250 n2 += 2;
251 if (*n2 == '/')
252 n2++;
253 num = strtoul(n2, &ep, 10);
254 if (ep == n2 || *ep)
255 num = -1;
256 else {
257 sprintf(devnm, "md%s%d", use_mdp ? "_d":"", num);
258 if (mddev_busy(devnm))
259 num = -1;
260 }
261 }
262
263 if (num < 0) {
264 /* need to choose a free number. */
265 char *_devnm = find_free_devnm(use_mdp);
266 if (devnm == NULL) {
267 pr_err("No avail md devices - aborting\n");
268 return -1;
269 }
270 strcpy(devnm, _devnm);
271 } else {
272 sprintf(devnm, "%s%d", use_mdp?"md_d":"md", num);
273 if (mddev_busy(devnm)) {
274 pr_err("%s is already in use.\n",
275 dev);
276 return -1;
277 }
278 }
279
280 sprintf(devname, "/dev/%s", devnm);
281
282 if (cname[0] == 0 && name) {
283 /* Need to find a name if we can
284 * We don't completely trust 'name'. Truncate to
285 * reasonable length and remove '/'
286 */
287 char *cp;
288 struct map_ent *map = NULL;
289 int conflict = 1;
290 int unum = 0;
291 int cnlen;
292 strncpy(cname, name, 200);
293 cname[200] = 0;
294 for (cp = cname; *cp ; cp++)
295 switch (*cp) {
296 case '/':
297 *cp = '-';
298 break;
299 case ' ':
300 case '\t':
301 *cp = '_';
302 break;
303 }
304
305 if (trustworthy == LOCAL ||
306 (trustworthy == FOREIGN && strchr(cname, ':') != NULL)) {
307 /* Only need suffix if there is a conflict */
308 if (map_by_name(&map, cname) == NULL)
309 conflict = 0;
310 }
311 cnlen = strlen(cname);
312 while (conflict) {
313 if (trustworthy == METADATA && !isdigit(cname[cnlen-1]))
314 sprintf(cname+cnlen, "%d", unum);
315 else
316 /* add _%d to FOREIGN array that don't
317 * a 'host:' prefix
318 */
319 sprintf(cname+cnlen, "_%d", unum);
320 unum++;
321 if (map_by_name(&map, cname) == NULL)
322 conflict = 0;
323 }
324 }
325
326 if (dev && dev[0] == '/')
327 strcpy(chosen, dev);
328 else if (cname[0] == 0)
329 strcpy(chosen, devname);
330
331 /* We have a device number and name.
332 * If we cannot detect udev, we need to make
333 * devices and links ourselves.
334 */
335 if (!use_udev()) {
336 /* Make sure 'devname' exists and 'chosen' is a symlink to it */
337 if (lstat(devname, &stb) == 0) {
338 /* Must be the correct device, else error */
339 if ((stb.st_mode&S_IFMT) != S_IFBLK ||
340 stb.st_rdev != (dev_t)devnm2devid(devnm)) {
341 pr_err("%s exists but looks wrong, please fix\n",
342 devname);
343 return -1;
344 }
345 } else {
346 if (mknod(devname, S_IFBLK|0600,
347 devnm2devid(devnm)) != 0) {
348 pr_err("failed to create %s\n",
349 devname);
350 return -1;
351 }
352 if (chown(devname, ci->uid, ci->gid))
353 perror("chown");
354 if (chmod(devname, ci->mode))
355 perror("chmod");
356 stat(devname, &stb);
357 add_dev(devname, &stb, 0, NULL);
358 }
359 if (use_mdp == 1)
360 make_parts(devname, parts);
361
362 if (strcmp(chosen, devname) != 0) {
363 if (mkdir("/dev/md",0700) == 0) {
364 if (chown("/dev/md", ci->uid, ci->gid))
365 perror("chown /dev/md");
366 if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
367 perror("chmod /dev/md");
368 }
369
370 if (dev && strcmp(chosen, dev) == 0)
371 /* We know we are allowed to use this name */
372 unlink(chosen);
373
374 if (lstat(chosen, &stb) == 0) {
375 char buf[300];
376 ssize_t link_len = readlink(chosen, buf, sizeof(buf)-1);
377 if (link_len >= 0)
378 buf[link_len] = '\0';
379
380 if ((stb.st_mode & S_IFMT) != S_IFLNK ||
381 link_len < 0 ||
382 strcmp(buf, devname) != 0) {
383 pr_err("%s exists - ignoring\n",
384 chosen);
385 strcpy(chosen, devname);
386 }
387 } else if (symlink(devname, chosen) != 0)
388 pr_err("failed to create %s: %s\n",
389 chosen, strerror(errno));
390 if (use_mdp && strcmp(chosen, devname) != 0)
391 make_parts(chosen, parts);
392 }
393 }
394 mdfd = open_dev_excl(devnm);
395 if (mdfd < 0)
396 pr_err("unexpected failure opening %s\n",
397 devname);
398 return mdfd;
399 }
400
401 /* Open this and check that it is an md device.
402 * On success, return filedescriptor.
403 * On failure, return -1 if it doesn't exist,
404 * or -2 if it exists but is not an md device.
405 */
406 int open_mddev(char *dev, int report_errors)
407 {
408 int mdfd = open(dev, O_RDWR);
409 if (mdfd < 0 && errno == EACCES)
410 mdfd = open(dev, O_RDONLY);
411 if (mdfd < 0) {
412 if (report_errors)
413 pr_err("error opening %s: %s\n",
414 dev, strerror(errno));
415 return -1;
416 }
417 if (md_get_version(mdfd) <= 0) {
418 close(mdfd);
419 if (report_errors)
420 pr_err("%s does not appear to be "
421 "an md device\n", dev);
422 return -2;
423 }
424 return mdfd;
425 }