mdadm: improve the dlm locking mechanism for clustered raid

[thirdparty/mdadm.git] / Query.c

/*
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2002-2009 Neil Brown <neilb@suse.de>
 *
 *
 *    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@suse.de>
 */

#include	"mdadm.h"
#include	"md_p.h"
#include	"md_u.h"

int Query(char *dev)
{
	/* Give a brief description of the device,
	 * whether it is an md device and whether it has
	 * a superblock
	 */
	int fd;
	int ioctlerr, staterr;
	int superror;
	int level, raid_disks, spare_disks;
	struct mdinfo info;
	struct mdinfo *sra;
	struct supertype *st = NULL;
	unsigned long long larray_size;
	struct stat stb;
	char *mddev;
	mdu_disk_info_t disc;
	char *activity;

	fd = open(dev, O_RDONLY);
	if (fd < 0){
		pr_err("cannot open %s: %s\n", dev, strerror(errno));
		return 1;
	}

	if (fstat(fd, &stb) < 0)
		staterr = errno;
	else
		staterr = 0;

	ioctlerr = 0;

	sra = sysfs_read(fd, dev, GET_DISKS | GET_LEVEL | GET_DEVS | GET_STATE);
	if (sra) {
		level = sra->array.level;
		raid_disks = sra->array.raid_disks;
		spare_disks = sra->array.spare_disks;
	} else {
		mdu_array_info_t array;

		if (md_get_array_info(fd, &array) < 0) {
			ioctlerr = errno;
			level = -1;
			raid_disks = -1;
			spare_disks = -1;
		} else {
			level = array.level;
			raid_disks = array.raid_disks;
			spare_disks = array.spare_disks;
		}
	}

	if (!ioctlerr && !staterr) {
		if (!get_dev_size(fd, NULL, &larray_size))
			larray_size = 0;
	}

	if (ioctlerr == ENODEV)
		printf("%s: is an md device which is not active\n", dev);
	else if (ioctlerr)
		printf("%s: is an md device, but gives \"%s\" when queried\n",
		       dev, strerror(ioctlerr));
	else if (staterr)
		printf("%s: is not a valid md device, returning %s\n",
		       dev, strerror(ioctlerr));
	else {
		printf("%s: %s %s %d devices, %d spare%s. Use mdadm --detail for more detail.\n",
		       dev, human_size_brief(larray_size,IEC),
		       map_num(pers, level), raid_disks,
		       spare_disks, spare_disks == 1 ? "" : "s");
	}
	st = guess_super(fd);
	if (st && st->ss->compare_super != NULL)
		superror = st->ss->load_super(st, fd, dev);
	else
		superror = -1;
	close(fd);
	if (superror == 0) {
		/* array might be active... */
		int uuid[4];
		struct map_ent *me, *map = NULL;
		st->ss->getinfo_super(st, &info, NULL);
		st->ss->uuid_from_super(st, uuid);
		me = map_by_uuid(&map, uuid);
		if (me) {
			mddev = me->path;
			disc.number = info.disk.number;
			activity = "undetected";
			if (mddev && (fd = open(mddev, O_RDONLY))>=0) {
				if (md_array_active(fd)) {
					if (md_get_disk_info(fd, &disc) >= 0 &&
					    makedev((unsigned)disc.major,(unsigned)disc.minor) == stb.st_rdev)
						activity = "active";
					else
						activity = "mismatch";
				}
				close(fd);
			}
		} else {
			activity = "inactive";
			mddev = "array";
		}
		printf("%s: device %d in %d device %s %s %s.  Use mdadm --examine for more detail.\n",
		       dev,
		       info.disk.number, info.array.raid_disks,
		       activity,
		       map_num(pers, info.array.level),
		       mddev);
		if (st->ss == &super0)
			put_md_name(mddev);
	}
	return 0;
}