Default to --auto=yes
[thirdparty/mdadm.git] / mdopen.c
CommitLineData
b5e64645
NB
1/*
2 * mdadm - manage Linux "md" devices aka RAID arrays.
3 *
4f589ad0 4 * Copyright (C) 2001-2006 Neil Brown <neilb@suse.de>
b5e64645
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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
0a6e1c67
NB
34
35void make_dev_symlink(char *dev)
36{
37 char *new = strdup(dev);
38
39 if (!new) return;
40 /* /dev/md/0 -> /dev/md0
41 * /dev/md/d0 -> /dev/md_d0
42 */
43 if (isdigit(new[8]))
44 strcpy(new+7, new+8);
45 else
46 new[7] = '_';
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ML
47 if (symlink(dev+5, new))
48 perror(new);
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49}
50
51
38098016 52void make_parts(char *dev, int cnt, int symlinks)
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NB
53{
54 /* make 'cnt' partition devices for 'dev'
55 * We use the major/minor from dev and add 1..cnt
8d80900b 56 * If dev ends with a digit, we add "p%d" else "%d"
b5e64645
NB
57 * If the name exists, we use it's owner/mode,
58 * else that of dev
59 */
60 struct stat stb;
61 int major, minor;
62 int i;
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NB
63 int nlen = strlen(dev) + 20;
64 char *name = malloc(nlen);
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65 int dig = isdigit(dev[strlen(dev)-1]);
66
f1ae21c4 67 if (cnt==0) cnt=4;
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68 if (stat(dev, &stb)!= 0)
69 return;
70 if (!S_ISBLK(stb.st_mode))
71 return;
0df46c2a
NB
72 major = major(stb.st_rdev);
73 minor = minor(stb.st_rdev);
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74 for (i=1; i <= cnt ; i++) {
75 struct stat stb2;
8f23b0b3 76 snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
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NB
77 if (stat(name, &stb2)==0) {
78 if (!S_ISBLK(stb2.st_mode))
79 continue;
0df46c2a 80 if (stb2.st_rdev == makedev(major, minor+i))
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81 continue;
82 unlink(name);
83 } else {
84 stb2 = stb;
85 }
1e0d770c
NB
86 if (mknod(name, S_IFBLK | 0600, makedev(major, minor+i)))
87 perror("mknod");
88 if (chown(name, stb2.st_uid, stb2.st_gid))
89 perror("chown");
90 if (chmod(name, stb2.st_mode & 07777))
91 perror("chmod");
38098016 92 if (symlinks && strncmp(name, "/dev/md/", 8) == 0)
0a6e1c67 93 make_dev_symlink(name);
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94 stat(name, &stb2);
95 add_dev(name, &stb2, 0, NULL);
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96 }
97}
98
0a6e1c67 99
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100/*
101 * Open a given md device, and check that it really is one.
102 * If 'autof' is given, then we need to create, or recreate, the md device.
103 * If the name already exists, and is not a block device, we fail.
104 * If it exists and is not an md device, is not the right type (partitioned or not),
105 * or is currently in-use, we remove the device, but remember the owner and mode.
8d80900b 106 * If it now doesn't exist, we find a new md array and create the device.
5bbb4842 107 * Default ownership/mode comes from config file.
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108 */
109int open_mddev(char *dev, int autof)
110{
111 int mdfd;
112 struct stat stb;
113 int major = MD_MAJOR;
a0ef61bf 114 int minor = 0;
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NB
115 int must_remove = 0;
116 struct mdstat_ent *mdlist;
117 int num;
8aec876d 118 struct createinfo *ci = conf_get_create_info();
f1ae21c4 119 int parts;
b5e64645 120
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121 if (autof == 0)
122 autof = ci->autof;
123
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NB
124 parts = autof >> 3;
125 autof &= 7;
126
127 if (autof && autof != 1) {
b5e64645
NB
128 /* autof is set, so we need to check that the name is ok,
129 * and possibly create one if not
130 */
f1ae21c4 131 int std;
b5e64645 132 stb.st_mode = 0;
0bbc98b5 133 if (stat(dev, &stb)==0 && ! S_ISBLK(stb.st_mode)) {
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134 fprintf(stderr, Name ": %s is not a block device.\n",
135 dev);
136 return -1;
137 }
138 /* check major number is correct */
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NB
139 num = -1;
140 std = is_standard(dev, &num);
141 if (std>0) major = get_mdp_major();
142 switch(autof) {
143 case 2: /* only create is_standard names */
144 if (!std && !stb.st_mode) {
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NB
145 fprintf(stderr, Name
146 ": %s does not exist and is not a 'standard' name "
147 "so it cannot be created\n", dev);
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NB
148 return -1;
149 }
150 break;
151 case 3: /* create md, reject std>0 */
152 if (std > 0) {
75723446
NB
153 fprintf(stderr, Name ": that --auto option "
154 "not compatable with device named %s\n", dev);
f1ae21c4
NB
155 return -1;
156 }
157 break;
158 case 4: /* create mdp, reject std<0 */
159 if (std < 0) {
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NB
160 fprintf(stderr, Name ": that --auto option "
161 "not compatable with device named %s\n", dev);
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NB
162 return -1;
163 }
164 break;
165 case 5: /* default to md if not standard */
166 break;
167 case 6: /* default to mdp if not standard */
168 if (std == 0) major = get_mdp_major();
169 break;
170 }
171 /* major is final. num is -1 if not standard */
0df46c2a 172 if (stb.st_mode && major(stb.st_rdev) != major)
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173 must_remove = 1;
174 if (stb.st_mode && !must_remove) {
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175 /* looks ok, see if it is available */
176 mdfd = open(dev, O_RDWR, 0);
177 if (mdfd < 0) {
178 fprintf(stderr, Name ": error opening %s: %s\n",
179 dev, strerror(errno));
180 return -1;
181 } else if (md_get_version(mdfd) <= 0) {
182 fprintf(stderr, Name ": %s does not appear to be an md device\n",
183 dev);
184 close(mdfd);
185 return -1;
186 }
e60c27d0
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187 if (major != MD_MAJOR && parts > 0)
188 make_parts(dev, parts, ci->symlinks);
189 return mdfd;
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190 }
191 /* Ok, need to find a minor that is not in use.
8d80900b
NB
192 * If the device name is in a 'standard' format,
193 * intuit the minor from that, else
194 * easiest to read /proc/mdstat, and hunt through for
b5e64645
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195 * an unused number
196 */
f1ae21c4
NB
197 if (num < 0) {
198 /* need to pick an unused number */
22a88995 199 mdlist = mdstat_read(0, 0);
e7bb5d23
NB
200 /* Choose a large number. Start from 127 and search down,
201 * but if nothing is found, start really big
202 */
203 for (num = 127 ; num != 128 ; num = num ? num-1 : (1<<22)-1) {
8d80900b 204 struct mdstat_ent *me;
f1ae21c4
NB
205 int devnum = num;
206 if (major != MD_MAJOR)
207 devnum = -1-num;
208
8d80900b 209 for (me=mdlist; me; me=me->next)
f1ae21c4 210 if (me->devnum == devnum)
8d80900b
NB
211 break;
212 if (!me) {
e7bb5d23 213 /* doesn't exist in mdstat.
8d80900b 214 * make sure it is new to /dev too
b5e64645 215 */
8d80900b 216 char *dn;
f1ae21c4
NB
217 if (major != MD_MAJOR)
218 minor = num << MdpMinorShift;
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NB
219 else
220 minor = num;
16c6fa80 221 dn = map_dev(major,minor, 0);
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NB
222 if (dn==NULL || is_standard(dn, NULL)) {
223 /* this number only used by a 'standard' name,
224 * so it is safe to use
225 */
226 break;
227 }
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228 }
229 }
f1ae21c4
NB
230 } else if (major == MD_MAJOR)
231 minor = num;
232 else
233 minor = num << MdpMinorShift;
8d80900b 234 /* major and minor have been chosen */
f1ae21c4 235
8d80900b
NB
236 /* If it was a 'standard' name and it is in-use, then
237 * the device could already be correct
238 */
0df46c2a
NB
239 if (stb.st_mode && major(stb.st_rdev) == major &&
240 minor(stb.st_rdev) == minor)
8d80900b
NB
241 ;
242 else {
0df46c2a
NB
243 if (major(makedev(major,minor)) != major ||
244 minor(makedev(major,minor)) != minor) {
245 fprintf(stderr, Name ": Need newer C library to use more than 4 partitionable md devices, sorry\n");
246 return -1;
247 }
8d80900b
NB
248 if (must_remove)
249 unlink(dev);
250
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NB
251 if (strncmp(dev, "/dev/md/", 8) == 0) {
252 if (mkdir("/dev/md",0700)==0) {
3a43c803
ML
253 if (chown("/dev/md", ci->uid, ci->gid))
254 perror("chown /dev/md");
255 if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
256 perror("chmod /dev/md");
0a6e1c67
NB
257 }
258 }
0df46c2a 259 if (mknod(dev, S_IFBLK|0600, makedev(major, minor))!= 0) {
8d80900b 260 fprintf(stderr, Name ": failed to create %s\n", dev);
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261 return -1;
262 }
8d80900b 263 if (must_remove) {
1e0d770c
NB
264 if (chown(dev, stb.st_uid, stb.st_gid))
265 perror("chown");
266 if (chmod(dev, stb.st_mode & 07777))
267 perror("chmod");
5bbb4842
NB
268 } else {
269 if (chown(dev, ci->uid, ci->gid))
270 perror("chown");
271 if (chmod(dev, ci->mode))
272 perror("chmod");
8d80900b 273 }
173fc515
NB
274 stat(dev, &stb);
275 add_dev(dev, &stb, 0, NULL);
38098016 276 if (ci->symlinks && strncmp(dev, "/dev/md/", 8) == 0)
0a6e1c67 277 make_dev_symlink(dev);
f1ae21c4 278 if (major != MD_MAJOR)
38098016 279 make_parts(dev,parts, ci->symlinks);
b5e64645 280 }
b5e64645
NB
281 }
282 mdfd = open(dev, O_RDWR, 0);
283 if (mdfd < 0)
284 fprintf(stderr, Name ": error opening %s: %s\n",
285 dev, strerror(errno));
286 else if (md_get_version(mdfd) <= 0) {
287 fprintf(stderr, Name ": %s does not appear to be an md device\n",
288 dev);
289 close(mdfd);
290 mdfd = -1;
291 }
292 return mdfd;
293}
294