[thirdparty/mdadm.git] / mdopen.c

/*
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2001-2002 Neil Brown <neilb@cse.unsw.edu.au>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *    Author: Neil Brown
 *    Email: <neilb@cse.unsw.edu.au>
 *    Paper: Neil Brown
 *           School of Computer Science and Engineering
 *           The University of New South Wales
 *           Sydney, 2052
 *           Australia
 */

#include "mdadm.h"
#include "md_p.h"
#include <ctype.h>

void make_parts(char *dev, int cnt)
{
	/* make 'cnt' partition devices for 'dev'
	 * We use the major/minor from dev and add 1..cnt
	 * If dev ends with a digit, we add "p%d" else "%d"
	 * If the name exists, we use it's owner/mode,
	 * else that of dev
	 */
	struct stat stb;
	int major, minor;
	int i;
	int nlen = strlen(dev) + 20;
	char *name = malloc(nlen);
	int dig = isdigit(dev[strlen(dev)-1]);

	if (stat(dev, &stb)!= 0)
		return;
	if (!S_ISBLK(stb.st_mode))
		return;
	major = major(stb.st_rdev);
	minor = minor(stb.st_rdev);
	for (i=1; i <= cnt ; i++) {
		struct stat stb2;
		snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
		if (stat(name, &stb2)==0) {
			if (!S_ISBLK(stb2.st_mode))
				continue;
			if (stb2.st_rdev == makedev(major, minor+i))
				continue;
			unlink(name);
		} else {
			stb2 = stb;
		}
		mknod(name, S_IFBLK | 0600, makedev(major, minor+i));
		chown(name, stb2.st_uid, stb2.st_gid);
		chmod(name, stb2.st_mode & 07777);
		stat(name, &stb2);
		add_dev(name, &stb2, 0, NULL);
	}
}

/*
 * Open a given md device, and check that it really is one.
 * If 'autof' is given, then we need to create, or recreate, the md device.
 * If the name already exists, and is not a block device, we fail.
 * If it exists and is not an md device, is not the right type (partitioned or not),
 * or is currently in-use, we remove the device, but remember the owner and mode.
 * If it now doesn't exist, we find a new md array and create the device.
 * Default ownership is user=0, group=0 perm=0600
 */
int open_mddev(char *dev, int autof)
{
	int mdfd;
	struct stat stb;
	int major = MD_MAJOR;
	int minor = 0;
	int must_remove = 0;
	struct mdstat_ent *mdlist;
	int num;

	if (autof) {
		/* autof is set, so we need to check that the name is ok,
		 * and possibly create one if not
		 */
		if (autof == -2 && !is_standard(dev, NULL)) {
			fprintf(stderr, Name ": --auto=yes requires a 'standard' md device name, not %s\n", dev);
			return -1;
		}
		stb.st_mode = 0;
		if (stat(dev, &stb)==0 && ! S_ISBLK(stb.st_mode)) {
			fprintf(stderr, Name ": %s is not a block device.\n",
				dev);
			return -1;
		}
		/* check major number is correct */
		if (autof>0)
			major = get_mdp_major();
		if (stb.st_mode && major(stb.st_rdev) != major)
			must_remove = 1;
		if (stb.st_mode && !must_remove) {
			mdu_array_info_t array;
			/* looks ok, see if it is available */
			mdfd = open(dev, O_RDWR, 0);
			if (mdfd < 0) {
				fprintf(stderr, Name ": error opening %s: %s\n",
					dev, strerror(errno));
				return -1;
			} else if (md_get_version(mdfd) <= 0) {
				fprintf(stderr, Name ": %s does not appear to be an md device\n",
					dev);
				close(mdfd);
				return -1;
			}
			if (ioctl(mdfd, GET_ARRAY_INFO, &array)==0) {
				/* already active */
				must_remove = 1;
				close(mdfd);
			} else {
				if (autof > 0)
					make_parts(dev, autof);
				return mdfd;
			}
		}
		/* Ok, need to find a minor that is not in use.
		 * If the device name is in a 'standard' format,
		 * intuit the minor from that, else
		 * easiest to read /proc/mdstat, and hunt through for
		 * an unused number 
		 */
		switch(is_standard(dev, &num)) {
		case -1: /* non partitioned */
			if (autof > 0) {
				fprintf(stderr, Name ": that --auto option not compatable with device named %s\n", dev);
				return -1;
			}
			minor = num;
			num = -1-num;
			break;
		case 1: /* partitioned */
			if (autof == -1) {
				fprintf(stderr, Name ": that --auto option not compatable with device named %s\n", dev);
				return -1;
			}
			minor = num <<  MdpMinorShift;
			major = get_mdp_major();
			break;
		case 0: /* not standard, pick an unused number */
			mdlist = mdstat_read(0);
			for (num= (autof>0)?-1:0 ; ; num+= (autof>2)?-1:1) {
				struct mdstat_ent *me;
				for (me=mdlist; me; me=me->next)
					if (me->devnum == num)
						break;
				if (!me) {
					/* doesn't exist if mdstat.
					 * make sure it is new to /dev too
					 */
					char *dn;
					if (autof > 0) 
						minor = (-1-num) << MdpMinorShift;
					else
						minor = num;
					dn = map_dev(major,minor);
					if (dn==NULL || is_standard(dn, NULL)) {
						/* this number only used by a 'standard' name,
						 * so it is safe to use
						 */
						break;
					}
				}
			}
		}
		/* major and minor have been chosen */
		
		/* If it was a 'standard' name and it is in-use, then
		 * the device could already be correct
		 */
		if (stb.st_mode && major(stb.st_rdev) == major &&
		    minor(stb.st_rdev) == minor)
			;
		else {
			if (major(makedev(major,minor)) != major ||
			    minor(makedev(major,minor)) != minor) {
				fprintf(stderr, Name ": Need newer C library to use more than 4 partitionable md devices, sorry\n");
				return -1;
			}
			if (must_remove)
				unlink(dev);

			if (mknod(dev, S_IFBLK|0600, makedev(major, minor))!= 0) {
				fprintf(stderr, Name ": failed to create %s\n", dev);
				return -1;
			}
			if (must_remove) {
				chown(dev, stb.st_uid, stb.st_gid);
				chmod(dev, stb.st_mode & 07777);
			}
			stat(dev, &stb);
			add_dev(dev, &stb, 0, NULL);
			make_parts(dev,autof);
		}
	}
	mdfd = open(dev, O_RDWR, 0);
	if (mdfd < 0)
		fprintf(stderr, Name ": error opening %s: %s\n",
			dev, strerror(errno));
	else if (md_get_version(mdfd) <= 0) {
		fprintf(stderr, Name ": %s does not appear to be an md device\n",
			dev);
		close(mdfd);
		mdfd = -1;
	}
	return mdfd;
}
Commit	Line	Data
b5e64645 NB	1	/*
	2	* mdadm - manage Linux "md" devices aka RAID arrays.
	3	*
	4	* Copyright (C) 2001-2002 Neil Brown <neilb@cse.unsw.edu.au>
	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	void make_parts(char *dev, int cnt)
	35	{
	36	/* make 'cnt' partition devices for 'dev'
	37	* We use the major/minor from dev and add 1..cnt
8d80900b	38	* If dev ends with a digit, we add "p%d" else "%d"
b5e64645 NB	39	* If the name exists, we use it's owner/mode,
	40	* else that of dev
	41	*/
	42	struct stat stb;
	43	int major, minor;
	44	int i;
8f23b0b3 NB	45	int nlen = strlen(dev) + 20;
8f23b0b3 NB	46	char *name = malloc(nlen);
b5e64645 NB	47	int dig = isdigit(dev[strlen(dev)-1]);
	48
	49	if (stat(dev, &stb)!= 0)
	50	return;
	51	if (!S_ISBLK(stb.st_mode))
	52	return;
0df46c2a NB	53	major = major(stb.st_rdev);
0df46c2a NB	54	minor = minor(stb.st_rdev);
b5e64645 NB	55	for (i=1; i <= cnt ; i++) {
b5e64645 NB	56	struct stat stb2;
8f23b0b3	57	snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
b5e64645 NB	58	if (stat(name, &stb2)==0) {
	59	if (!S_ISBLK(stb2.st_mode))
	60	continue;
0df46c2a	61	if (stb2.st_rdev == makedev(major, minor+i))
b5e64645 NB	62	continue;
	63	unlink(name);
	64	} else {
	65	stb2 = stb;
	66	}
0df46c2a	67	mknod(name, S_IFBLK \| 0600, makedev(major, minor+i));
b5e64645 NB	68	chown(name, stb2.st_uid, stb2.st_gid);
b5e64645 NB	69	chmod(name, stb2.st_mode & 07777);
173fc515 NB	70	stat(name, &stb2);
173fc515 NB	71	add_dev(name, &stb2, 0, NULL);
b5e64645 NB	72	}
	73	}
	74
	75	/*
	76	* Open a given md device, and check that it really is one.
	77	* If 'autof' is given, then we need to create, or recreate, the md device.
	78	* If the name already exists, and is not a block device, we fail.
	79	* If it exists and is not an md device, is not the right type (partitioned or not),
	80	* or is currently in-use, we remove the device, but remember the owner and mode.
8d80900b	81	* If it now doesn't exist, we find a new md array and create the device.
b5e64645 NB	82	* Default ownership is user=0, group=0 perm=0600
	83	*/
	84	int open_mddev(char *dev, int autof)
	85	{
	86	int mdfd;
	87	struct stat stb;
	88	int major = MD_MAJOR;
a0ef61bf	89	int minor = 0;
b5e64645 NB	90	int must_remove = 0;
	91	struct mdstat_ent *mdlist;
	92	int num;
	93
	94	if (autof) {
	95	/* autof is set, so we need to check that the name is ok,
	96	* and possibly create one if not
	97	*/
48f7b27a NB	98	if (autof == -2 && !is_standard(dev, NULL)) {
	99	fprintf(stderr, Name ": --auto=yes requires a 'standard' md device name, not %s\n", dev);
	100	return -1;
	101	}
b5e64645	102	stb.st_mode = 0;
0bbc98b5	103	if (stat(dev, &stb)==0 && ! S_ISBLK(stb.st_mode)) {
b5e64645 NB	104	fprintf(stderr, Name ": %s is not a block device.\n",
	105	dev);
	106	return -1;
	107	}
	108	/* check major number is correct */
	109	if (autof>0)
	110	major = get_mdp_major();
0df46c2a	111	if (stb.st_mode && major(stb.st_rdev) != major)
b5e64645 NB	112	must_remove = 1;
	113	if (stb.st_mode && !must_remove) {
	114	mdu_array_info_t array;
	115	/* looks ok, see if it is available */
	116	mdfd = open(dev, O_RDWR, 0);
	117	if (mdfd < 0) {
	118	fprintf(stderr, Name ": error opening %s: %s\n",
	119	dev, strerror(errno));
	120	return -1;
	121	} else if (md_get_version(mdfd) <= 0) {
	122	fprintf(stderr, Name ": %s does not appear to be an md device\n",
	123	dev);
	124	close(mdfd);
	125	return -1;
	126	}
	127	if (ioctl(mdfd, GET_ARRAY_INFO, &array)==0) {
	128	/* already active */
	129	must_remove = 1;
	130	close(mdfd);
	131	} else {
	132	if (autof > 0)
	133	make_parts(dev, autof);
	134	return mdfd;
	135	}
	136	}
	137	/* Ok, need to find a minor that is not in use.
8d80900b NB	138	* If the device name is in a 'standard' format,
	139	* intuit the minor from that, else
	140	* easiest to read /proc/mdstat, and hunt through for
b5e64645 NB	141	* an unused number
b5e64645 NB	142	*/
8d80900b NB	143	switch(is_standard(dev, &num)) {
	144	case -1: /* non partitioned */
	145	if (autof > 0) {
	146	fprintf(stderr, Name ": that --auto option not compatable with device named %s\n", dev);
	147	return -1;
	148	}
	149	minor = num;
	150	num = -1-num;
	151	break;
	152	case 1: /* partitioned */
	153	if (autof == -1) {
	154	fprintf(stderr, Name ": that --auto option not compatable with device named %s\n", dev);
	155	return -1;
	156	}
	157	minor = num << MdpMinorShift;
	158	major = get_mdp_major();
	159	break;
	160	case 0: /* not standard, pick an unused number */
	161	mdlist = mdstat_read(0);
	162	for (num= (autof>0)?-1:0 ; ; num+= (autof>2)?-1:1) {
	163	struct mdstat_ent *me;
	164	for (me=mdlist; me; me=me->next)
	165	if (me->devnum == num)
	166	break;
	167	if (!me) {
	168	/* doesn't exist if mdstat.
	169	* make sure it is new to /dev too
b5e64645	170	*/
8d80900b NB	171	char *dn;
	172	if (autof > 0)
	173	minor = (-1-num) << MdpMinorShift;
	174	else
	175	minor = num;
	176	dn = map_dev(major,minor);
	177	if (dn==NULL \|\| is_standard(dn, NULL)) {
	178	/* this number only used by a 'standard' name,
	179	* so it is safe to use
	180	*/
	181	break;
	182	}
b5e64645 NB	183	}
	184	}
	185	}
8d80900b NB	186	/* major and minor have been chosen */
	187
	188	/* If it was a 'standard' name and it is in-use, then
	189	* the device could already be correct
	190	*/
0df46c2a NB	191	if (stb.st_mode && major(stb.st_rdev) == major &&
0df46c2a NB	192	minor(stb.st_rdev) == minor)
8d80900b NB	193	;
8d80900b NB	194	else {
0df46c2a NB	195	if (major(makedev(major,minor)) != major \|\|
	196	minor(makedev(major,minor)) != minor) {
	197	fprintf(stderr, Name ": Need newer C library to use more than 4 partitionable md devices, sorry\n");
	198	return -1;
	199	}
8d80900b NB	200	if (must_remove)
	201	unlink(dev);
	202
0df46c2a	203	if (mknod(dev, S_IFBLK\|0600, makedev(major, minor))!= 0) {
8d80900b	204	fprintf(stderr, Name ": failed to create %s\n", dev);
b5e64645 NB	205	return -1;
b5e64645 NB	206	}
8d80900b NB	207	if (must_remove) {
	208	chown(dev, stb.st_uid, stb.st_gid);
	209	chmod(dev, stb.st_mode & 07777);
	210	}
173fc515 NB	211	stat(dev, &stb);
173fc515 NB	212	add_dev(dev, &stb, 0, NULL);
8d80900b	213	make_parts(dev,autof);
b5e64645	214	}
b5e64645 NB	215	}
	216	mdfd = open(dev, O_RDWR, 0);
	217	if (mdfd < 0)
	218	fprintf(stderr, Name ": error opening %s: %s\n",
	219	dev, strerror(errno));
	220	else if (md_get_version(mdfd) <= 0) {
	221	fprintf(stderr, Name ": %s does not appear to be an md device\n",
	222	dev);
	223	close(mdfd);
	224	mdfd = -1;
	225	}
	226	return mdfd;
	227	}
	228