]> git.ipfire.org Git - thirdparty/mdadm.git/blob - mdopen.c
Merge branch 'master' into devel-3.0
[thirdparty/mdadm.git] / mdopen.c
1 /*
2 * mdadm - manage Linux "md" devices aka RAID arrays.
3 *
4 * Copyright (C) 2001-2006 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@cse.unsw.edu.au>
23 * Paper: Neil Brown
24 * School of Computer Science and Engineering
25 * The University of New South Wales
26 * Sydney, 2052
27 * Australia
28 */
29
30 #include "mdadm.h"
31 #include "md_p.h"
32 #include <ctype.h>
33
34
35 void make_parts(char *dev, int cnt)
36 {
37 /* make 'cnt' partition devices for 'dev'
38 * If dev is a device name we use the
39 * major/minor from dev and add 1..cnt
40 * If it is a symlink, we make similar symlinks.
41 * If dev ends with a digit, we add "p%d" else "%d"
42 * If the name exists, we use it's owner/mode,
43 * else that of dev
44 */
45 struct stat stb;
46 int major_num = major_num; /* quiet gcc -Os unitialized warning */
47 int minor_num = minor_num; /* quiet gcc -Os unitialized warning */
48 int odig = odig; /* quiet gcc -Os unitialized warning */
49 int i;
50 int nlen = strlen(dev) + 20;
51 char *name = malloc(nlen);
52 int dig = isdigit(dev[strlen(dev)-1]);
53 char orig[1024];
54 char sym[1024];
55 int err;
56
57 if (cnt==0) cnt=4;
58 if (lstat(dev, &stb)!= 0)
59 return;
60 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 } else if (S_ISBLK(stb.st_mode)) {
67 major_num = major(stb.st_rdev);
68 minor_num = minor(stb.st_rdev);
69 } else
70 return;
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))
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 }
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 cbuf[400];
149 if (chosen == NULL)
150 chosen = cbuf;
151
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
163 if (dev) {
164
165 if (strncmp(dev, "/dev/md/", 8) == 0) {
166 strcpy(cname, dev+8);
167 } else if (strncmp(dev, "/dev/", 5) == 0) {
168 char *e = dev + strlen(dev);
169 while (e > dev && isdigit(e[-1]))
170 e--;
171 if (e[0])
172 num = strtoul(e, NULL, 10);
173 strcpy(cname, dev+5);
174 cname[e-(dev+5)] = 0;
175 /* name *must* be mdXX or md_dXX in this context */
176 if (num < 0 ||
177 (strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) {
178 fprintf(stderr, Name ": %s is an invalid name "
179 "for an md device. Try /dev/md/%s\n",
180 dev, dev+5);
181 return -1;
182 }
183 if (strcmp(cname, "md") == 0)
184 use_mdp = 0;
185 else
186 use_mdp = 1;
187 /* recreate name: /dev/md/0 or /dev/md/d0 */
188 sprintf(cname, "%s%d", use_mdp?"d":"", num);
189 } else
190 strcpy(cname, dev);
191
192 /* 'cname' must not contain a slash, and may not be
193 * empty.
194 */
195 if (strchr(cname, '/') != NULL) {
196 fprintf(stderr, Name ": %s is an invalid name "
197 "for an md device.\n", dev);
198 return -1;
199 }
200 if (cname[0] == 0) {
201 fprintf(stderr, Name ": %s is an invalid name "
202 "for an md device (empty!).", dev);
203 return -1;
204 }
205 if (num < 0) {
206 /* If cname is 'N' or 'dN', we get dev number
207 * from there.
208 */
209 char *sp = cname;
210 char *ep;
211 if (cname[0] == 'd')
212 sp++;
213 num = strtoul(sp, &ep, 10);
214 if (ep == sp || *ep || num < 0)
215 num = -1;
216 else if (cname[0] == 'd')
217 use_mdp = 1;
218 else
219 use_mdp = 0;
220 }
221 }
222
223 /* Now determine device number */
224 /* named 'METADATA' cannot use 'mdp'. */
225 if (name && name[0] == 0)
226 name = NULL;
227 if (name && trustworthy == METADATA && use_mdp == 1) {
228 fprintf(stderr, Name ": %s is not allowed for a %s container. "
229 "Consider /dev/md%d.\n", dev, name, num);
230 return -1;
231 }
232 if (name && trustworthy == METADATA)
233 use_mdp = 0;
234 if (use_mdp == -1) {
235 if (autof == 4 || autof == 6)
236 use_mdp = 1;
237 else
238 use_mdp = 0;
239 }
240 if (num < 0 && trustworthy == LOCAL && name) {
241 /* if name is numeric, use that for num
242 * if it is not already in use */
243 char *ep;
244 num = strtoul(name, &ep, 10);
245 if (ep == name || *ep)
246 num = -1;
247 else if (mddev_busy(use_mdp ? (-1-num) : num))
248 num = -1;
249 }
250
251 if (num < 0) {
252 /* need to choose a free number. */
253 num = find_free_devnum(use_mdp);
254 if (num == NoMdDev) {
255 fprintf(stderr, Name ": No avail md devices - aborting\n");
256 return -1;
257 }
258 } else {
259 num = use_mdp ? (-1-num) : num;
260 if (mddev_busy(num)) {
261 fprintf(stderr, Name ": %s is already in use.\n",
262 dev);
263 return -1;
264 }
265 }
266
267 if (num < 0)
268 sprintf(devname, "/dev/md_d%d", -1-num);
269 else
270 sprintf(devname, "/dev/md%d", num);
271
272 if (cname[0] == 0 && name) {
273 /* Need to find a name if we can
274 * We don't completely trust 'name'. Truncate to
275 * reasonable length and remove '/'
276 */
277 char *cp;
278 struct map_ent *map = NULL;
279 int conflict = 1;
280 int unum = 0;
281 int cnlen;
282 strncpy(cname, name, 200);
283 cname[200] = 0;
284 while ((cp = strchr(cname, '/')) != NULL)
285 *cp = '-';
286 if (trustworthy == LOCAL ||
287 (trustworthy == FOREIGN && strchr(cname, ':') != NULL)) {
288 /* Only need suffix if there is a conflict */
289 if (map_by_name(&map, cname) == NULL)
290 conflict = 0;
291 }
292 cnlen = strlen(cname);
293 while (conflict) {
294 if (trustworthy == METADATA)
295 sprintf(cname+cnlen, "%d", unum);
296 else
297 /* add _%d to FOREIGN array that don't
298 * a 'host:' prefix
299 */
300 sprintf(cname+cnlen, "_%d", unum);
301 unum++;
302 if (map_by_name(&map, cname) == NULL)
303 conflict = 0;
304 }
305 }
306 if (cname[0] == 0)
307 strcpy(chosen, devname);
308
309 /* We have a device number and name.
310 * If we cannot detect udev, we need to make
311 * devices and links ourselves.
312 */
313 if (stat("/dev/.udev", &stb) != 0 ||
314 check_env("MDADM_NO_UDEV")) {
315 /* Make sure 'devname' exists and 'chosen' is a symlink to it */
316 if (lstat(devname, &stb) == 0) {
317 /* Must be the correct device, else error */
318 if ((stb.st_mode&S_IFMT) != S_IFBLK ||
319 stb.st_rdev != makedev(dev2major(num),dev2minor(num))) {
320 fprintf(stderr, Name ": %s exists but looks wrong, please fix\n",
321 devname);
322 return -1;
323 }
324 } else {
325 if (mknod(devname, S_IFBLK|0600,
326 makedev(dev2major(num),dev2minor(num))) != 0) {
327 fprintf(stderr, Name ": failed to create %s\n",
328 devname);
329 return -1;
330 }
331 if (chown(devname, ci->uid, ci->gid))
332 perror("chown");
333 if (chmod(devname, ci->mode))
334 perror("chmod");
335 stat(devname, &stb);
336 add_dev(devname, &stb, 0, NULL);
337 }
338 if (use_mdp == 1)
339 make_parts(devname, parts);
340 if (strcmp(chosen, devname) != 0) {
341
342 if (mkdir("/dev/md",0700)==0) {
343 if (chown("/dev/md", ci->uid, ci->gid))
344 perror("chown /dev/md");
345 if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
346 perror("chmod /dev/md");
347 }
348
349 if (dev && strcmp(chosen, dev) == 0)
350 /* We know we are allowed to use this name */
351 unlink(chosen);
352
353 if (lstat(chosen, &stb) == 0) {
354 char buf[300];
355 if ((stb.st_mode & S_IFMT) != S_IFLNK ||
356 readlink(chosen, buf, 300) <0 ||
357 strcmp(buf, devname) != 0) {
358 fprintf(stderr, Name ": %s exists - ignoring\n",
359 chosen);
360 strcpy(chosen, devname);
361 }
362 } else if (symlink(devname, chosen) != 0)
363 fprintf(stderr, Name ": failed to create %s: %s\n",
364 chosen, strerror(errno));
365 if (use_mdp && strcmp(chosen, devname) != 0)
366 make_parts(chosen, parts);
367 }
368 }
369 mdfd = open_dev_excl(num);
370 if (mdfd < 0)
371 fprintf(stderr, Name ": unexpected failure opening %s\n",
372 devname);
373 return mdfd;
374 }
375
376
377 /* Open this and check that it is an md device.
378 * On success, return filedescriptor.
379 * On failure, return -1 if it doesn't exist,
380 * or -2 if it exists but is not an md device.
381 */
382 int open_mddev(char *dev, int report_errors)
383 {
384 int mdfd = open(dev, O_RDWR);
385 if (mdfd < 0) {
386 if (report_errors)
387 fprintf(stderr, Name ": error opening %s: %s\n",
388 dev, strerror(errno));
389 return -1;
390 }
391 if (md_get_version(mdfd) <= 0) {
392 close(mdfd);
393 if (report_errors)
394 fprintf(stderr, Name ": %s does not appear to be "
395 "an md device\n", dev);
396 return -2;
397 }
398 return mdfd;
399 }