]>
git.ipfire.org Git - thirdparty/mdadm.git/blob - mdopen.c
2 * mdadm - manage Linux "md" devices aka RAID arrays.
4 * Copyright (C) 2001-2006 Neil Brown <neilb@suse.de>
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.
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.
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
22 * Email: <neilb@cse.unsw.edu.au>
24 * School of Computer Science and Engineering
25 * The University of New South Wales
35 void make_dev_symlink(char *dev
)
37 char *new = strdup(dev
);
40 /* /dev/md/0 -> /dev/md0
41 * /dev/md/d0 -> /dev/md_d0
47 if (symlink(dev
+5, new))
52 void make_parts(char *dev
, int cnt
, int symlinks
)
54 /* make 'cnt' partition devices for 'dev'
55 * We use the major/minor from dev and add 1..cnt
56 * If dev ends with a digit, we add "p%d" else "%d"
57 * If the name exists, we use it's owner/mode,
61 int major_num
, minor_num
;
63 int nlen
= strlen(dev
) + 20;
64 char *name
= malloc(nlen
);
65 int dig
= isdigit(dev
[strlen(dev
)-1]);
68 if (stat(dev
, &stb
)!= 0)
70 if (!S_ISBLK(stb
.st_mode
))
72 major_num
= major(stb
.st_rdev
);
73 minor_num
= minor(stb
.st_rdev
);
74 for (i
=1; i
<= cnt
; i
++) {
76 snprintf(name
, nlen
, "%s%s%d", dev
, dig
?"p":"", i
);
77 if (stat(name
, &stb2
)==0) {
78 if (!S_ISBLK(stb2
.st_mode
))
80 if (stb2
.st_rdev
== makedev(major_num
, minor_num
+i
))
86 if (mknod(name
, S_IFBLK
| 0600, makedev(major_num
, minor_num
+i
)))
88 if (chown(name
, stb2
.st_uid
, stb2
.st_gid
))
90 if (chmod(name
, stb2
.st_mode
& 07777))
92 if (symlinks
&& strncmp(name
, "/dev/md/", 8) == 0)
93 make_dev_symlink(name
);
95 add_dev(name
, &stb2
, 0, NULL
);
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.
106 * If it now doesn't exist, we find a new md array and create the device.
107 * Default ownership/mode comes from config file.
109 int open_mddev(char *dev
, int autof
)
113 int major_num
= MD_MAJOR
;
116 struct mdstat_ent
*mdlist
;
118 struct createinfo
*ci
= conf_get_create_info();
127 if (autof
&& autof
!= 1) {
128 /* autof is set, so we need to check that the name is ok,
129 * and possibly create one if not
133 if (stat(dev
, &stb
)==0 && ! S_ISBLK(stb
.st_mode
)) {
134 fprintf(stderr
, Name
": %s is not a block device.\n",
138 /* check major number is correct */
140 std
= is_standard(dev
, &num
);
141 if (std
>0) major_num
= get_mdp_major();
143 case 2: /* only create is_standard names */
144 if (!std
&& !stb
.st_mode
) {
146 ": %s does not exist and is not a 'standard' name "
147 "so it cannot be created\n", dev
);
151 case 3: /* create md, reject std>0 */
153 fprintf(stderr
, Name
": that --auto option "
154 "not compatable with device named %s\n", dev
);
158 case 4: /* create mdp, reject std<0 */
160 fprintf(stderr
, Name
": that --auto option "
161 "not compatable with device named %s\n", dev
);
164 major_num
= get_mdp_major();
166 case 5: /* default to md if not standard */
168 case 6: /* default to mdp if not standard */
169 if (std
== 0) major_num
= get_mdp_major();
172 /* major is final. num is -1 if not standard */
173 if (stb
.st_mode
&& major(stb
.st_rdev
) != major_num
)
175 if (stb
.st_mode
&& !must_remove
) {
176 /* looks ok, see if it is available */
177 mdfd
= open(dev
, O_RDWR
, 0);
179 fprintf(stderr
, Name
": error opening %s: %s\n",
180 dev
, strerror(errno
));
182 } else if (md_get_version(mdfd
) <= 0) {
183 fprintf(stderr
, Name
": %s does not appear to be an md device\n",
188 if (major_num
!= MD_MAJOR
&& parts
> 0)
189 make_parts(dev
, parts
, ci
->symlinks
);
192 /* Ok, need to find a minor that is not in use.
193 * If the device name is in a 'standard' format,
194 * intuit the minor from that, else
195 * easiest to read /proc/mdstat, and hunt through for
199 /* need to pick an unused number */
200 mdlist
= mdstat_read(0, 0);
201 /* Choose a large number. Start from 127 and search down,
202 * but if nothing is found, start really big
204 for (num
= 127 ; num
!= 128 ; num
= num
? num
-1 : (1<<22)-1) {
205 struct mdstat_ent
*me
;
207 if (major_num
!= MD_MAJOR
)
210 for (me
=mdlist
; me
; me
=me
->next
)
211 if (me
->devnum
== devnum
)
214 /* doesn't exist in mdstat.
215 * make sure it is new to /dev too
218 if (major_num
!= MD_MAJOR
)
219 minor_num
= num
<< MdpMinorShift
;
222 dn
= map_dev(major_num
,minor_num
, 0);
223 if (dn
==NULL
|| is_standard(dn
, NULL
)) {
224 /* this number only used by a 'standard' name,
225 * so it is safe to use
231 } else if (major_num
== MD_MAJOR
)
234 minor_num
= num
<< MdpMinorShift
;
235 /* major and minor have been chosen */
237 /* If it was a 'standard' name and it is in-use, then
238 * the device could already be correct
240 if (stb
.st_mode
&& major(stb
.st_rdev
) == major_num
&&
241 minor(stb
.st_rdev
) == minor_num
)
244 if (major(makedev(major_num
,minor_num
)) != major_num
||
245 minor(makedev(major_num
,minor_num
)) != minor_num
) {
246 fprintf(stderr
, Name
": Need newer C library to use more than 4 partitionable md devices, sorry\n");
252 if (strncmp(dev
, "/dev/md/", 8) == 0) {
253 if (mkdir("/dev/md",0700)==0) {
254 if (chown("/dev/md", ci
->uid
, ci
->gid
))
255 perror("chown /dev/md");
256 if (chmod("/dev/md", ci
->mode
| ((ci
->mode
>>2) & 0111)))
257 perror("chmod /dev/md");
260 if (mknod(dev
, S_IFBLK
|0600, makedev(major_num
, minor_num
))!= 0) {
261 fprintf(stderr
, Name
": failed to create %s\n", dev
);
265 if (chown(dev
, stb
.st_uid
, stb
.st_gid
))
267 if (chmod(dev
, stb
.st_mode
& 07777))
270 if (chown(dev
, ci
->uid
, ci
->gid
))
272 if (chmod(dev
, ci
->mode
))
276 add_dev(dev
, &stb
, 0, NULL
);
277 if (ci
->symlinks
&& strncmp(dev
, "/dev/md/", 8) == 0)
278 make_dev_symlink(dev
);
279 if (major_num
!= MD_MAJOR
)
280 make_parts(dev
,parts
, ci
->symlinks
);
283 mdfd
= open(dev
, O_RDWR
, 0);
285 fprintf(stderr
, Name
": error opening %s: %s\n",
286 dev
, strerror(errno
));
287 else if (md_get_version(mdfd
) <= 0) {
288 fprintf(stderr
, Name
": %s does not appear to be an md device\n",
297 int open_mddev_devnum(char *devname
, int devnum
, char *name
, char *chosen_name
)
299 /* Open the md device with number 'devnum', possibly using 'devname',
300 * possibly constructing a name with 'name', but in any case, copying
301 * the name into 'chosen_name'
303 int major_num
, minor_num
;
308 strcpy(chosen_name
, devname
);
309 else if (name
&& strchr(name
,'/') == NULL
) {
310 char *n
= strchr(name
, ':');
311 if (n
) n
++; else n
= name
;
312 if (isdigit(*n
) && devnum
< 0)
313 sprintf(chosen_name
, "/dev/md/d%s", n
);
315 sprintf(chosen_name
, "/dev/md/%s", n
);
318 sprintf(chosen_name
, "/dev/md%d", devnum
);
320 sprintf(chosen_name
, "/dev/md/d%d", -1-devnum
);
323 major_num
= MD_MAJOR
;
326 major_num
= get_mdp_major();
327 minor_num
= (-1-devnum
) << 6;
329 if (stat(chosen_name
, &stb
) == 0) {
330 /* It already exists. Check it is right. */
331 if ( ! S_ISBLK(stb
.st_mode
) ||
332 stb
.st_rdev
!= makedev(major_num
, minor_num
)) {
337 /* special case: if --incremental is suggesting a name
338 * in /dev/md/, we make sure the directory exists.
340 if (strncmp(chosen_name
, "/dev/md/", 8) == 0) {
341 struct createinfo
*ci
= conf_get_create_info();
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
|
346 ((ci
->mode
>>2) & 0111)))
347 perror("chmod /dev/md");
351 if (mknod(chosen_name
, S_IFBLK
| 0600,
352 makedev(major_num
, minor_num
)) != 0) {
355 /* FIXME chown/chmod ?? */
358 /* Simple locking to avoid --incr being called for the same
359 * array multiple times in parallel.
361 for (i
= 0; i
< 25 ; i
++) {
364 fd
= open(chosen_name
, O_RDWR
|O_EXCL
);
365 if (fd
>= 0 || errno
!= EBUSY
)