[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;
	char *name = malloc(strlen(dev) + 20);
	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;
		sprintf(name, "%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);
	}
}

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