Adding upstream version 4.2.upstream/4.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2378 insertions, 0 deletions

diff --git a/util.c b/util.c
new file mode 100644
index 0000000..3d05d07
--- /dev/null
+++ b/util.c
@@ -0,0 +1,2378 @@
+/*
+ * mdadm - manage Linux "md" devices aka RAID arrays.
+ *
+ * Copyright (C) 2001-2013 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	<sys/socket.h>
+#include	<sys/utsname.h>
+#include	<sys/wait.h>
+#include	<sys/un.h>
+#include	<sys/resource.h>
+#include	<sys/vfs.h>
+#include	<sys/mman.h>
+#include	<linux/magic.h>
+#include	<poll.h>
+#include	<ctype.h>
+#include	<dirent.h>
+#include	<signal.h>
+#include	<dlfcn.h>
+
+
+/*
+ * following taken from linux/blkpg.h because they aren't
+ * anywhere else and it isn't safe to #include linux/ * stuff.
+ */
+
+#define BLKPG      _IO(0x12,105)
+
+/* The argument structure */
+struct blkpg_ioctl_arg {
+	int op;
+	int flags;
+	int datalen;
+	void *data;
+};
+
+/* The subfunctions (for the op field) */
+#define BLKPG_ADD_PARTITION	1
+#define BLKPG_DEL_PARTITION	2
+
+/* Sizes of name fields. Unused at present. */
+#define BLKPG_DEVNAMELTH	64
+#define BLKPG_VOLNAMELTH	64
+
+/* The data structure for ADD_PARTITION and DEL_PARTITION */
+struct blkpg_partition {
+	long long start;		/* starting offset in bytes */
+	long long length;		/* length in bytes */
+	int pno;			/* partition number */
+	char devname[BLKPG_DEVNAMELTH];	/* partition name, like sda5 or c0d1p2,
+					   to be used in kernel messages */
+	char volname[BLKPG_VOLNAMELTH];	/* volume label */
+};
+
+#include "part.h"
+
+/* Force a compilation error if condition is true */
+#define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
+
+/* Force a compilation error if condition is true, but also produce a
+   result (of value 0 and type size_t), so the expression can be used
+   e.g. in a structure initializer (or where-ever else comma expressions
+   aren't permitted). */
+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
+
+static int is_dlm_hooks_ready = 0;
+
+int dlm_funs_ready(void)
+{
+	return is_dlm_hooks_ready ? 1 : 0;
+}
+
+static struct dlm_hooks *dlm_hooks = NULL;
+struct dlm_lock_resource *dlm_lock_res = NULL;
+static int ast_called = 0;
+
+struct dlm_lock_resource {
+	dlm_lshandle_t *ls;
+	struct dlm_lksb lksb;
+};
+
+/* Using poll(2) to wait for and dispatch ASTs */
+static int poll_for_ast(dlm_lshandle_t ls)
+{
+	struct pollfd pfd;
+
+	pfd.fd = dlm_hooks->ls_get_fd(ls);
+	pfd.events = POLLIN;
+
+	while (!ast_called)
+	{
+		if (poll(&pfd, 1, 0) < 0)
+		{
+			perror("poll");
+			return -1;
+		}
+		dlm_hooks->dispatch(dlm_hooks->ls_get_fd(ls));
+	}
+	ast_called = 0;
+
+	return 0;
+}
+
+static void dlm_ast(void *arg)
+{
+	ast_called = 1;
+}
+
+static char *cluster_name = NULL;
+/* Create the lockspace, take bitmapXXX locks on all the bitmaps. */
+int cluster_get_dlmlock(void)
+{
+	int ret = -1;
+	char str[64];
+	int flags = LKF_NOQUEUE;
+	int retry_count = 0;
+
+	if (!dlm_funs_ready()) {
+		pr_err("Something wrong with dlm library\n");
+		return -1;
+	}
+
+	ret = get_cluster_name(&cluster_name);
+	if (ret) {
+		pr_err("The md can't get cluster name\n");
+		return -1;
+	}
+
+	dlm_lock_res = xmalloc(sizeof(struct dlm_lock_resource));
+	dlm_lock_res->ls = dlm_hooks->open_lockspace(cluster_name);
+	if (!dlm_lock_res->ls) {
+		dlm_lock_res->ls = dlm_hooks->create_lockspace(cluster_name, O_RDWR);
+		if (!dlm_lock_res->ls) {
+			pr_err("%s failed to create lockspace\n", cluster_name);
+			return -ENOMEM;
+		}
+	} else {
+		pr_err("open existed %s lockspace\n", cluster_name);
+	}
+
+	snprintf(str, 64, "bitmap%s", cluster_name);
+retry:
+	ret = dlm_hooks->ls_lock(dlm_lock_res->ls, LKM_PWMODE,
+				 &dlm_lock_res->lksb, flags, str, strlen(str),
+				 0, dlm_ast, dlm_lock_res, NULL, NULL);
+	if (ret) {
+		pr_err("error %d when get PW mode on lock %s\n", errno, str);
+		/* let's try several times if EAGAIN happened */
+		if (dlm_lock_res->lksb.sb_status == EAGAIN && retry_count < 10) {
+			sleep(10);
+			retry_count++;
+			goto retry;
+		}
+		dlm_hooks->release_lockspace(cluster_name, dlm_lock_res->ls, 1);
+		return ret;
+	}
+
+	/* Wait for it to complete */
+	poll_for_ast(dlm_lock_res->ls);
+
+	if (dlm_lock_res->lksb.sb_status) {
+		pr_err("failed to lock cluster\n");
+		return -1;
+	}
+	return 1;
+}
+
+int cluster_release_dlmlock(void)
+{
+	int ret = -1;
+
+	if (!cluster_name)
+                goto out;
+
+	if (!dlm_lock_res->lksb.sb_lkid)
+                goto out;
+
+	ret = dlm_hooks->ls_unlock_wait(dlm_lock_res->ls,
+					dlm_lock_res->lksb.sb_lkid, 0,
+					&dlm_lock_res->lksb);
+	if (ret) {
+		pr_err("error %d happened when unlock\n", errno);
+		/* XXX make sure the lock is unlocked eventually */
+                goto out;
+	}
+
+	/* Wait for it to complete */
+	poll_for_ast(dlm_lock_res->ls);
+
+	errno =	dlm_lock_res->lksb.sb_status;
+	if (errno != EUNLOCK) {
+		pr_err("error %d happened in ast when unlock lockspace\n",
+		       errno);
+		/* XXX make sure the lockspace is unlocked eventually */
+                goto out;
+	}
+
+	ret = dlm_hooks->release_lockspace(cluster_name, dlm_lock_res->ls, 1);
+	if (ret) {
+		pr_err("error %d happened when release lockspace\n", errno);
+		/* XXX make sure the lockspace is released eventually */
+                goto out;
+	}
+	free(dlm_lock_res);
+
+out:
+	return ret;
+}
+
+int md_array_valid(int fd)
+{
+	struct mdinfo *sra;
+	int ret;
+
+	sra = sysfs_read(fd, NULL, GET_ARRAY_STATE);
+	if (sra) {
+		if (sra->array_state != ARRAY_UNKNOWN_STATE)
+			ret = 0;
+		else
+			ret = -ENODEV;
+
+		free(sra);
+	} else {
+		/*
+		 * GET_ARRAY_INFO doesn't provide access to the proper state
+		 * information, so fallback to a basic check for raid_disks != 0
+		 */
+		ret = ioctl(fd, RAID_VERSION);
+	}
+
+	return !ret;
+}
+
+int md_array_active(int fd)
+{
+	struct mdinfo *sra;
+	struct mdu_array_info_s array;
+	int ret = 0;
+
+	sra = sysfs_read(fd, NULL, GET_ARRAY_STATE);
+	if (sra) {
+		if (!md_array_is_active(sra))
+			ret = -ENODEV;
+
+		free(sra);
+	} else {
+		/*
+		 * GET_ARRAY_INFO doesn't provide access to the proper state
+		 * information, so fallback to a basic check for raid_disks != 0
+		 */
+		ret = ioctl(fd, GET_ARRAY_INFO, &array);
+	}
+
+	return !ret;
+}
+
+int md_array_is_active(struct mdinfo *info)
+{
+	return (info->array_state != ARRAY_CLEAR &&
+		info->array_state != ARRAY_INACTIVE &&
+		info->array_state != ARRAY_UNKNOWN_STATE);
+}
+
+/*
+ * Get array info from the kernel. Longer term we want to deprecate the
+ * ioctl and get it from sysfs.
+ */
+int md_get_array_info(int fd, struct mdu_array_info_s *array)
+{
+	return ioctl(fd, GET_ARRAY_INFO, array);
+}
+
+/*
+ * Set array info
+ */
+int md_set_array_info(int fd, struct mdu_array_info_s *array)
+{
+	return ioctl(fd, SET_ARRAY_INFO, array);
+}
+
+/*
+ * Get disk info from the kernel.
+ */
+int md_get_disk_info(int fd, struct mdu_disk_info_s *disk)
+{
+	return ioctl(fd, GET_DISK_INFO, disk);
+}
+
+int get_linux_version()
+{
+	struct utsname name;
+	char *cp;
+	int a = 0, b = 0,c = 0;
+	if (uname(&name) <0)
+		return -1;
+
+	cp = name.release;
+	a = strtoul(cp, &cp, 10);
+	if (*cp == '.')
+		b = strtoul(cp+1, &cp, 10);
+	if (*cp == '.')
+		c = strtoul(cp+1, &cp, 10);
+
+	return (a*1000000)+(b*1000)+c;
+}
+
+int mdadm_version(char *version)
+{
+	int a, b, c;
+	char *cp;
+
+	if (!version)
+		version = Version;
+
+	cp = strchr(version, '-');
+	if (!cp || *(cp+1) != ' ' || *(cp+2) != 'v')
+		return -1;
+	cp += 3;
+	a = strtoul(cp, &cp, 10);
+	if (*cp != '.')
+		return -1;
+	b = strtoul(cp+1, &cp, 10);
+	if (*cp == '.')
+		c = strtoul(cp+1, &cp, 10);
+	else
+		c = 0;
+	if (*cp != ' ' && *cp != '-')
+		return -1;
+	return (a*1000000)+(b*1000)+c;
+}
+
+unsigned long long parse_size(char *size)
+{
+	/* parse 'size' which should be a number optionally
+	 * followed by 'K', 'M'. 'G' or 'T'.
+	 * Without a suffix, K is assumed.
+	 * Number returned is in sectors (half-K)
+	 * INVALID_SECTORS returned on error.
+	 */
+	char *c;
+	long long s = strtoll(size, &c, 10);
+	if (s > 0) {
+		switch (*c) {
+		case 'K':
+			c++;
+		default:
+			s *= 2;
+			break;
+		case 'M':
+			c++;
+			s *= 1024 * 2;
+			break;
+		case 'G':
+			c++;
+			s *= 1024 * 1024 * 2;
+			break;
+		case 'T':
+			c++;
+			s *= 1024 * 1024 * 1024 * 2LL;
+			break;
+		case 's': /* sectors */
+			c++;
+			break;
+		}
+	} else
+		s = INVALID_SECTORS;
+	if (*c)
+		s = INVALID_SECTORS;
+	return s;
+}
+
+int is_near_layout_10(int layout)
+{
+	int fc, fo;
+
+	fc = (layout >> 8) & 255;
+	fo = layout & (1 << 16);
+	if (fc > 1 || fo > 0)
+		return 0;
+	return 1;
+}
+
+int parse_layout_10(char *layout)
+{
+	int copies, rv;
+	char *cp;
+	/* Parse the layout string for raid10 */
+	/* 'f', 'o' or 'n' followed by a number <= raid_disks */
+	if ((layout[0] !=  'n' && layout[0] != 'f' && layout[0] != 'o') ||
+	    (copies = strtoul(layout+1, &cp, 10)) < 1 ||
+	    copies > 200 ||
+	    *cp)
+		return -1;
+	if (layout[0] == 'n')
+		rv = 256 + copies;
+	else if (layout[0] == 'o')
+		rv = 0x10000 + (copies<<8) + 1;
+	else
+		rv = 1 + (copies<<8);
+	return rv;
+}
+
+int parse_layout_faulty(char *layout)
+{
+	if (!layout)
+		return -1;
+	/* Parse the layout string for 'faulty' */
+	int ln = strcspn(layout, "0123456789");
+	char *m = xstrdup(layout);
+	int mode;
+	m[ln] = 0;
+	mode = map_name(faultylayout, m);
+	if (mode == UnSet)
+		return -1;
+
+	return mode | (atoi(layout+ln)<< ModeShift);
+}
+
+int parse_cluster_confirm_arg(char *input, char **devname, int *slot)
+{
+	char *dev;
+	*slot = strtoul(input, &dev, 10);
+	if (dev == input || dev[0] != ':')
+		return -1;
+	*devname = dev+1;
+	return 0;
+}
+
+void remove_partitions(int fd)
+{
+	/* remove partitions from this block devices.
+	 * This is used for components added to an array
+	 */
+#ifdef BLKPG_DEL_PARTITION
+	struct blkpg_ioctl_arg a;
+	struct blkpg_partition p;
+
+	a.op = BLKPG_DEL_PARTITION;
+	a.data = (void*)&p;
+	a.datalen = sizeof(p);
+	a.flags = 0;
+	memset(a.data, 0, a.datalen);
+	for (p.pno = 0; p.pno < 16; p.pno++)
+		ioctl(fd, BLKPG, &a);
+#endif
+}
+
+int test_partition(int fd)
+{
+	/* Check if fd is a whole-disk or a partition.
+	 * BLKPG will return EINVAL on a partition, and BLKPG_DEL_PARTITION
+	 * will return ENXIO on an invalid partition number.
+	 */
+	struct blkpg_ioctl_arg a;
+	struct blkpg_partition p;
+	a.op = BLKPG_DEL_PARTITION;
+	a.data = (void*)&p;
+	a.datalen = sizeof(p);
+	a.flags = 0;
+	memset(a.data, 0, a.datalen);
+	p.pno = 1<<30;
+	if (ioctl(fd, BLKPG, &a) == 0)
+		/* Very unlikely, but not a partition */
+		return 0;
+	if (errno == ENXIO || errno == ENOTTY)
+		/* not a partition */
+		return 0;
+
+	return 1;
+}
+
+int test_partition_from_id(dev_t id)
+{
+	char buf[20];
+	int fd, rv;
+
+	sprintf(buf, "%d:%d", major(id), minor(id));
+	fd = dev_open(buf, O_RDONLY);
+	if (fd < 0)
+		return -1;
+	rv = test_partition(fd);
+	close(fd);
+	return rv;
+}
+
+int enough(int level, int raid_disks, int layout, int clean, char *avail)
+{
+	int copies, first;
+	int i;
+	int avail_disks = 0;
+
+	for (i = 0; i < raid_disks; i++)
+		avail_disks += !!avail[i];
+
+	switch (level) {
+	case 10:
+		/* This is the tricky one - we need to check
+		 * which actual disks are present.
+		 */
+		copies = (layout&255)* ((layout>>8) & 255);
+		first = 0;
+		do {
+			/* there must be one of the 'copies' form 'first' */
+			int n = copies;
+			int cnt = 0;
+			int this = first;
+			while (n--) {
+				if (avail[this])
+					cnt++;
+				this = (this+1) % raid_disks;
+			}
+			if (cnt == 0)
+				return 0;
+			first = (first+(layout&255)) % raid_disks;
+		} while (first != 0);
+		return 1;
+
+	case LEVEL_MULTIPATH:
+		return avail_disks>= 1;
+	case LEVEL_LINEAR:
+	case 0:
+		return avail_disks == raid_disks;
+	case 1:
+		return avail_disks >= 1;
+	case 4:
+		if (avail_disks == raid_disks - 1 &&
+		    !avail[raid_disks - 1])
+			/* If just the parity device is missing, then we
+			 * have enough, even if not clean
+			 */
+			return 1;
+		/* FALL THROUGH */
+	case 5:
+		if (clean)
+			return avail_disks >= raid_disks-1;
+		else
+			return avail_disks >= raid_disks;
+	case 6:
+		if (clean)
+			return avail_disks >= raid_disks-2;
+		else
+			return avail_disks >= raid_disks;
+	default:
+		return 0;
+	}
+}
+
+char *__fname_from_uuid(int id[4], int swap, char *buf, char sep)
+{
+	int i, j;
+	char uuid[16];
+	char *c = buf;
+	strcpy(c, "UUID-");
+	c += strlen(c);
+	copy_uuid(uuid, id, swap);
+	for (i = 0; i < 4; i++) {
+		if (i)
+			*c++ = sep;
+		for (j = 3; j >= 0; j--) {
+			sprintf(c,"%02x", (unsigned char) uuid[j+4*i]);
+			c+= 2;
+		}
+	}
+	return buf;
+
+}
+
+char *fname_from_uuid(struct supertype *st, struct mdinfo *info,
+		      char *buf, char sep)
+{
+	// dirty hack to work around an issue with super1 superblocks...
+	// super1 superblocks need swapuuid set in order for assembly to
+	// work, but can't have it set if we want this printout to match
+	// all the other uuid printouts in super1.c, so we force swapuuid
+	// to 1 to make our printout match the rest of super1
+#if __BYTE_ORDER == BIG_ENDIAN
+	return __fname_from_uuid(info->uuid, 1, buf, sep);
+#else
+	return __fname_from_uuid(info->uuid, (st->ss == &super1) ? 1 :
+				 st->ss->swapuuid, buf, sep);
+#endif
+}
+
+int check_ext2(int fd, char *name)
+{
+	/*
+	 * Check for an ext2fs file system.
+	 * Superblock is always 1K at 1K offset
+	 *
+	 * s_magic is le16 at 56 == 0xEF53
+	 * report mtime - le32 at 44
+	 * blocks - le32 at 4
+	 * logblksize - le32 at 24
+	 */
+	unsigned char sb[1024];
+	time_t mtime;
+	unsigned long long size;
+	int bsize;
+	if (lseek(fd, 1024,0)!= 1024)
+		return 0;
+	if (read(fd, sb, 1024)!= 1024)
+		return 0;
+	if (sb[56] != 0x53 || sb[57] != 0xef)
+		return 0;
+
+	mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
+	bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
+	size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
+	size <<= bsize;
+	pr_err("%s appears to contain an ext2fs file system\n",
+		name);
+	cont_err("size=%lluK  mtime=%s", size, ctime(&mtime));
+	return 1;
+}
+
+int check_reiser(int fd, char *name)
+{
+	/*
+	 * superblock is at 64K
+	 * size is 1024;
+	 * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
+	 *
+	 */
+	unsigned char sb[1024];
+	unsigned long long size;
+	if (lseek(fd, 64*1024, 0) != 64*1024)
+		return 0;
+	if (read(fd, sb, 1024) != 1024)
+		return 0;
+	if (strncmp((char*)sb+52, "ReIsErFs",8) != 0 &&
+	    strncmp((char*)sb+52, "ReIsEr2Fs",9) != 0)
+		return 0;
+	pr_err("%s appears to contain a reiserfs file system\n",name);
+	size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
+	cont_err("size = %lluK\n", size*4);
+
+	return 1;
+}
+
+int check_raid(int fd, char *name)
+{
+	struct mdinfo info;
+	time_t crtime;
+	char *level;
+	struct supertype *st = guess_super(fd);
+
+	if (!st)
+		return 0;
+	if (st->ss->add_to_super != NULL) {
+		st->ss->load_super(st, fd, name);
+		/* Looks like a raid array .. */
+		pr_err("%s appears to be part of a raid array:\n", name);
+		st->ss->getinfo_super(st, &info, NULL);
+		st->ss->free_super(st);
+		crtime = info.array.ctime;
+		level = map_num(pers, info.array.level);
+		if (!level)
+			level = "-unknown-";
+		cont_err("level=%s devices=%d ctime=%s",
+			level, info.array.raid_disks, ctime(&crtime));
+	} else {
+		/* Looks like GPT or MBR */
+		pr_err("partition table exists on %s\n", name);
+	}
+	return 1;
+}
+
+int fstat_is_blkdev(int fd, char *devname, dev_t *rdev)
+{
+	struct stat stb;
+
+	if (fstat(fd, &stb) != 0) {
+		pr_err("fstat failed for %s: %s\n", devname, strerror(errno));
+		return 0;
+	}
+	if ((S_IFMT & stb.st_mode) != S_IFBLK) {
+		pr_err("%s is not a block device.\n", devname);
+		return 0;
+	}
+	if (rdev)
+		*rdev = stb.st_rdev;
+	return 1;
+}
+
+int stat_is_blkdev(char *devname, dev_t *rdev)
+{
+	struct stat stb;
+
+	if (stat(devname, &stb) != 0) {
+		pr_err("stat failed for %s: %s\n", devname, strerror(errno));
+		return 0;
+	}
+	if ((S_IFMT & stb.st_mode) != S_IFBLK) {
+		pr_err("%s is not a block device.\n", devname);
+		return 0;
+	}
+	if (rdev)
+		*rdev = stb.st_rdev;
+	return 1;
+}
+
+int ask(char *mesg)
+{
+	char *add = "";
+	int i;
+	for (i = 0; i < 5; i++) {
+		char buf[100];
+		fprintf(stderr, "%s%s", mesg, add);
+		fflush(stderr);
+		if (fgets(buf, 100, stdin)==NULL)
+			return 0;
+		if (buf[0]=='y' || buf[0]=='Y')
+			return 1;
+		if (buf[0]=='n' || buf[0]=='N')
+			return 0;
+		add = "(y/n) ";
+	}
+	pr_err("assuming 'no'\n");
+	return 0;
+}
+
+int is_standard(char *dev, int *nump)
+{
+	/* tests if dev is a "standard" md dev name.
+	 * i.e if the last component is "/dNN" or "/mdNN",
+	 * where NN is a string of digits
+	 * Returns 1 if a partitionable standard,
+	 *   -1 if non-partitonable,
+	 *   0 if not a standard name.
+	 */
+	char *d = strrchr(dev, '/');
+	int type = 0;
+	int num;
+	if (!d)
+		return 0;
+	if (strncmp(d, "/d",2) == 0)
+		d += 2, type = 1; /* /dev/md/dN{pM} */
+	else if (strncmp(d, "/md_d", 5) == 0)
+		d += 5, type = 1; /* /dev/md_dN{pM} */
+	else if (strncmp(d, "/md", 3) == 0)
+		d += 3, type = -1; /* /dev/mdN */
+	else if (d-dev > 3 && strncmp(d-2, "md/", 3) == 0)
+		d += 1, type = -1; /* /dev/md/N */
+	else
+		return 0;
+	if (!*d)
+		return 0;
+	num = atoi(d);
+	while (isdigit(*d))
+		d++;
+	if (*d)
+		return 0;
+	if (nump) *nump = num;
+
+	return type;
+}
+
+unsigned long calc_csum(void *super, int bytes)
+{
+	unsigned long long newcsum = 0;
+	int i;
+	unsigned int csum;
+	unsigned int *superc = (unsigned int*) super;
+
+	for(i = 0; i < bytes/4; i++)
+		newcsum += superc[i];
+	csum = (newcsum& 0xffffffff) + (newcsum>>32);
+#ifdef __alpha__
+/* The in-kernel checksum calculation is always 16bit on
+ * the alpha, though it is 32 bit on i386...
+ * I wonder what it is elsewhere... (it uses an API in
+ * a way that it shouldn't).
+ */
+	csum = (csum & 0xffff) + (csum >> 16);
+	csum = (csum & 0xffff) + (csum >> 16);
+#endif
+	return csum;
+}
+
+char *human_size(long long bytes)
+{
+	static char buf[47];
+
+	/* We convert bytes to either centi-M{ega,ibi}bytes,
+	 * centi-G{igi,ibi}bytes or centi-T{era,ebi}bytes
+	 * with appropriate rounding, and then print
+	 * 1/100th of those as a decimal.
+	 * We allow upto 2048Megabytes before converting to
+	 * gigabytes and 2048Gigabytes before converting to
+	 * terabytes, as that shows more precision and isn't
+	 * too large a number.
+	 */
+
+	if (bytes < 5000*1024)
+		buf[0] = 0;
+	else if (bytes < 2*1024LL*1024LL*1024LL) {
+		long cMiB = (bytes * 200LL / (1LL<<20) + 1) / 2;
+		long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
+		snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
+			cMiB/100, cMiB % 100, cMB/100, cMB % 100);
+	} else if (bytes < 2*1024LL*1024LL*1024LL*1024LL) {
+		long cGiB = (bytes * 200LL / (1LL<<30) +1) / 2;
+		long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
+		snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
+			cGiB/100, cGiB % 100, cGB/100, cGB % 100);
+	} else {
+		long cTiB = (bytes * 200LL / (1LL<<40) + 1) / 2;
+		long cTB  = (bytes / (1000000000000LL / 200LL) + 1) / 2;
+		snprintf(buf, sizeof(buf), " (%ld.%02ld TiB %ld.%02ld TB)",
+			cTiB/100, cTiB % 100, cTB/100, cTB % 100);
+	}
+	return buf;
+}
+
+char *human_size_brief(long long bytes, int prefix)
+{
+	static char buf[30];
+
+	/* We convert bytes to either centi-M{ega,ibi}bytes,
+	 * centi-G{igi,ibi}bytes or centi-T{era,ebi}bytes
+	 * with appropriate rounding, and then print
+	 * 1/100th of those as a decimal.
+	 * We allow upto 2048Megabytes before converting to
+	 * gigabytes and 2048Gigabytes before converting to
+	 * terabytes, as that shows more precision and isn't
+	 * too large a number.
+	 *
+	 * If prefix == IEC, we mean prefixes like kibi,mebi,gibi etc.
+	 * If prefix == JEDEC, we mean prefixes like kilo,mega,giga etc.
+	 */
+
+	if (bytes < 5000*1024)
+		buf[0] = 0;
+	else if (prefix == IEC) {
+		if (bytes < 2*1024LL*1024LL*1024LL) {
+			long cMiB = (bytes * 200LL / (1LL<<20) +1) /2;
+			snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
+				 cMiB/100, cMiB % 100);
+		} else if (bytes < 2*1024LL*1024LL*1024LL*1024LL) {
+			long cGiB = (bytes * 200LL / (1LL<<30) +1) /2;
+			snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
+				 cGiB/100, cGiB % 100);
+		} else {
+			long cTiB = (bytes * 200LL / (1LL<<40) + 1) / 2;
+			snprintf(buf, sizeof(buf), "%ld.%02ldTiB",
+				 cTiB/100, cTiB % 100);
+		}
+	}
+	else if (prefix == JEDEC) {
+		if (bytes < 2*1024LL*1024LL*1024LL) {
+			long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
+			snprintf(buf, sizeof(buf), "%ld.%02ldMB",
+				 cMB/100, cMB % 100);
+		} else if (bytes < 2*1024LL*1024LL*1024LL*1024LL) {
+			long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
+			snprintf(buf, sizeof(buf), "%ld.%02ldGB",
+				 cGB/100, cGB % 100);
+		} else {
+			long cTB  = (bytes / (1000000000000LL / 200LL) + 1) / 2;
+			snprintf(buf, sizeof(buf), "%ld.%02ldTB",
+				 cTB/100, cTB % 100);
+		}
+	}
+	else
+		buf[0] = 0;
+
+	return buf;
+}
+
+void print_r10_layout(int layout)
+{
+	int near = layout & 255;
+	int far = (layout >> 8) & 255;
+	int offset = (layout&0x10000);
+	char *sep = "";
+
+	if (near != 1) {
+		printf("%s near=%d", sep, near);
+		sep = ",";
+	}
+	if (far != 1)
+		printf("%s %s=%d", sep, offset?"offset":"far", far);
+	if (near*far == 1)
+		printf("NO REDUNDANCY");
+}
+
+unsigned long long calc_array_size(int level, int raid_disks, int layout,
+				   int chunksize, unsigned long long devsize)
+{
+	if (level == 1)
+		return devsize;
+	devsize &= ~(unsigned long long)((chunksize>>9)-1);
+	return get_data_disks(level, layout, raid_disks) * devsize;
+}
+
+int get_data_disks(int level, int layout, int raid_disks)
+{
+	int data_disks = 0;
+	switch (level) {
+	case 0: data_disks = raid_disks;
+		break;
+	case 1: data_disks = 1;
+		break;
+	case 4:
+	case 5: data_disks = raid_disks - 1;
+		break;
+	case 6: data_disks = raid_disks - 2;
+		break;
+	case 10: data_disks = raid_disks / (layout & 255) / ((layout>>8)&255);
+		break;
+	}
+
+	return data_disks;
+}
+
+dev_t devnm2devid(char *devnm)
+{
+	/* First look in /sys/block/$DEVNM/dev for %d:%d
+	 * If that fails, try parsing out a number
+	 */
+	char path[PATH_MAX];
+	char *ep;
+	int fd;
+	int mjr,mnr;
+
+	snprintf(path, sizeof(path), "/sys/block/%s/dev", devnm);
+	fd = open(path, O_RDONLY);
+	if (fd >= 0) {
+		char buf[20];
+		int n = read(fd, buf, sizeof(buf));
+		close(fd);
+		if (n > 0)
+			buf[n] = 0;
+		if (n > 0 && sscanf(buf, "%d:%d\n", &mjr, &mnr) == 2)
+			return makedev(mjr, mnr);
+	}
+	if (strncmp(devnm, "md_d", 4) == 0 &&
+	    isdigit(devnm[4]) &&
+	    (mnr = strtoul(devnm+4, &ep, 10)) >= 0 &&
+	    ep > devnm && *ep == 0)
+		return makedev(get_mdp_major(), mnr << MdpMinorShift);
+
+	if (strncmp(devnm, "md", 2) == 0 &&
+	    isdigit(devnm[2]) &&
+	    (mnr = strtoul(devnm+2, &ep, 10)) >= 0 &&
+	    ep > devnm && *ep == 0)
+		return makedev(MD_MAJOR, mnr);
+
+	return 0;
+}
+
+char *get_md_name(char *devnm)
+{
+	/* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
+	/* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
+
+	static char devname[50];
+	struct stat stb;
+	dev_t rdev = devnm2devid(devnm);
+	char *dn;
+
+	if (rdev == 0)
+		return 0;
+	if (strncmp(devnm, "md_", 3) == 0) {
+		snprintf(devname, sizeof(devname), "/dev/md/%s",
+			devnm + 3);
+		if (stat(devname, &stb) == 0 &&
+		    (S_IFMT&stb.st_mode) == S_IFBLK && (stb.st_rdev == rdev))
+			return devname;
+	}
+	snprintf(devname, sizeof(devname), "/dev/%s", devnm);
+	if (stat(devname, &stb) == 0 && (S_IFMT&stb.st_mode) == S_IFBLK &&
+	    (stb.st_rdev == rdev))
+		return devname;
+
+	snprintf(devname, sizeof(devname), "/dev/md/%s", devnm+2);
+	if (stat(devname, &stb) == 0 && (S_IFMT&stb.st_mode) == S_IFBLK &&
+	    (stb.st_rdev == rdev))
+		return devname;
+
+	dn = map_dev(major(rdev), minor(rdev), 0);
+	if (dn)
+		return dn;
+	snprintf(devname, sizeof(devname), "/dev/.tmp.%s", devnm);
+	if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
+		if (errno != EEXIST)
+			return NULL;
+
+	if (stat(devname, &stb) == 0 && (S_IFMT&stb.st_mode) == S_IFBLK &&
+	    (stb.st_rdev == rdev))
+		return devname;
+	unlink(devname);
+	return NULL;
+}
+
+void put_md_name(char *name)
+{
+	if (strncmp(name, "/dev/.tmp.md", 12) == 0)
+		unlink(name);
+}
+
+int get_maj_min(char *dev, int *major, int *minor)
+{
+	char *e;
+	*major = strtoul(dev, &e, 0);
+	return (e > dev && *e == ':' && e[1] &&
+		(*minor = strtoul(e+1, &e, 0)) >= 0 &&
+		*e == 0);
+}
+
+int dev_open(char *dev, int flags)
+{
+	/* like 'open', but if 'dev' matches %d:%d, create a temp
+	 * block device and open that
+	 */
+	int fd = -1;
+	char devname[32];
+	int major;
+	int minor;
+
+	if (!dev)
+		return -1;
+	flags |= O_DIRECT;
+
+	if (get_maj_min(dev, &major, &minor)) {
+		snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d:%d",
+			 (int)getpid(), major, minor);
+		if (mknod(devname, S_IFBLK|0600, makedev(major, minor)) == 0) {
+			fd = open(devname, flags);
+			unlink(devname);
+		}
+		if (fd < 0) {
+			/* Try /tmp as /dev appear to be read-only */
+			snprintf(devname, sizeof(devname),
+				 "/tmp/.tmp.md.%d:%d:%d",
+				 (int)getpid(), major, minor);
+			if (mknod(devname, S_IFBLK|0600,
+				  makedev(major, minor)) == 0) {
+				fd = open(devname, flags);
+				unlink(devname);
+			}
+		}
+	} else
+		fd = open(dev, flags);
+	return fd;
+}
+
+int open_dev_flags(char *devnm, int flags)
+{
+	dev_t devid;
+	char buf[20];
+
+	devid = devnm2devid(devnm);
+	sprintf(buf, "%d:%d", major(devid), minor(devid));
+	return dev_open(buf, flags);
+}
+
+int open_dev(char *devnm)
+{
+	return open_dev_flags(devnm, O_RDONLY);
+}
+
+int open_dev_excl(char *devnm)
+{
+	char buf[20];
+	int i;
+	int flags = O_RDWR;
+	dev_t devid = devnm2devid(devnm);
+	long delay = 1000;
+
+	sprintf(buf, "%d:%d", major(devid), minor(devid));
+	for (i = 0; i < 25; i++) {
+		int fd = dev_open(buf, flags|O_EXCL);
+		if (fd >= 0)
+			return fd;
+		if (errno == EACCES && flags == O_RDWR) {
+			flags = O_RDONLY;
+			continue;
+		}
+		if (errno != EBUSY)
+			return fd;
+		usleep(delay);
+		if (delay < 200000)
+			delay *= 2;
+	}
+	return -1;
+}
+
+int same_dev(char *one, char *two)
+{
+	struct stat st1, st2;
+	if (stat(one, &st1) != 0)
+		return 0;
+	if (stat(two, &st2) != 0)
+		return 0;
+	if ((st1.st_mode & S_IFMT) != S_IFBLK)
+		return 0;
+	if ((st2.st_mode & S_IFMT) != S_IFBLK)
+		return 0;
+	return st1.st_rdev == st2.st_rdev;
+}
+
+void wait_for(char *dev, int fd)
+{
+	int i;
+	struct stat stb_want;
+	long delay = 1000;
+
+	if (fstat(fd, &stb_want) != 0 ||
+	    (stb_want.st_mode & S_IFMT) != S_IFBLK)
+		return;
+
+	for (i = 0; i < 25; i++) {
+		struct stat stb;
+		if (stat(dev, &stb) == 0 &&
+		    (stb.st_mode & S_IFMT) == S_IFBLK &&
+		    (stb.st_rdev == stb_want.st_rdev))
+			return;
+		usleep(delay);
+		if (delay < 200000)
+			delay *= 2;
+	}
+	if (i == 25)
+		pr_err("timeout waiting for %s\n", dev);
+}
+
+struct superswitch *superlist[] =
+{
+	&super0, &super1,
+	&super_ddf, &super_imsm,
+	&mbr, &gpt,
+	NULL
+};
+
+struct supertype *super_by_fd(int fd, char **subarrayp)
+{
+	mdu_array_info_t array;
+	int vers;
+	int minor;
+	struct supertype *st = NULL;
+	struct mdinfo *sra;
+	char *verstr;
+	char version[20];
+	int i;
+	char *subarray = NULL;
+	char container[32] = "";
+
+	sra = sysfs_read(fd, NULL, GET_VERSION);
+
+	if (sra) {
+		vers = sra->array.major_version;
+		minor = sra->array.minor_version;
+		verstr = sra->text_version;
+	} else {
+		if (md_get_array_info(fd, &array))
+			array.major_version = array.minor_version = 0;
+		vers = array.major_version;
+		minor = array.minor_version;
+		verstr = "";
+	}
+
+	if (vers != -1) {
+		sprintf(version, "%d.%d", vers, minor);
+		verstr = version;
+	}
+	if (minor == -2 && is_subarray(verstr)) {
+		char *dev = verstr+1;
+
+		subarray = strchr(dev, '/');
+		if (subarray) {
+			*subarray++ = '\0';
+			subarray = xstrdup(subarray);
+		}
+		strcpy(container, dev);
+		sysfs_free(sra);
+		sra = sysfs_read(-1, container, GET_VERSION);
+		if (sra && sra->text_version[0])
+			verstr = sra->text_version;
+		else
+			verstr = "-no-metadata-";
+	}
+
+	for (i = 0; st == NULL && superlist[i]; i++)
+		st = superlist[i]->match_metadata_desc(verstr);
+
+	sysfs_free(sra);
+	if (st) {
+		st->sb = NULL;
+		if (subarrayp)
+			*subarrayp = subarray;
+		strcpy(st->container_devnm, container);
+		strcpy(st->devnm, fd2devnm(fd));
+	} else
+		free(subarray);
+
+	return st;
+}
+
+int dev_size_from_id(dev_t id, unsigned long long *size)
+{
+	char buf[20];
+	int fd;
+
+	sprintf(buf, "%d:%d", major(id), minor(id));
+	fd = dev_open(buf, O_RDONLY);
+	if (fd < 0)
+		return 0;
+	if (get_dev_size(fd, NULL, size)) {
+		close(fd);
+		return 1;
+	}
+	close(fd);
+	return 0;
+}
+
+int dev_sector_size_from_id(dev_t id, unsigned int *size)
+{
+	char buf[20];
+	int fd;
+
+	sprintf(buf, "%d:%d", major(id), minor(id));
+	fd = dev_open(buf, O_RDONLY);
+	if (fd < 0)
+		return 0;
+	if (get_dev_sector_size(fd, NULL, size)) {
+		close(fd);
+		return 1;
+	}
+	close(fd);
+	return 0;
+}
+
+struct supertype *dup_super(struct supertype *orig)
+{
+	struct supertype *st;
+
+	if (!orig)
+		return orig;
+	st = xcalloc(1, sizeof(*st));
+	st->ss = orig->ss;
+	st->max_devs = orig->max_devs;
+	st->minor_version = orig->minor_version;
+	st->ignore_hw_compat = orig->ignore_hw_compat;
+	st->data_offset = orig->data_offset;
+	st->sb = NULL;
+	st->info = NULL;
+	return st;
+}
+
+struct supertype *guess_super_type(int fd, enum guess_types guess_type)
+{
+	/* try each load_super to find the best match,
+	 * and return the best superswitch
+	 */
+	struct superswitch  *ss;
+	struct supertype *st;
+	unsigned int besttime = 0;
+	int bestsuper = -1;
+	int i;
+
+	st = xcalloc(1, sizeof(*st));
+	st->container_devnm[0] = 0;
+
+	for (i = 0; superlist[i]; i++) {
+		int rv;
+		ss = superlist[i];
+		if (guess_type == guess_array && ss->add_to_super == NULL)
+			continue;
+		if (guess_type == guess_partitions && ss->add_to_super != NULL)
+			continue;
+		memset(st, 0, sizeof(*st));
+		st->ignore_hw_compat = 1;
+		rv = ss->load_super(st, fd, NULL);
+		if (rv == 0) {
+			struct mdinfo info;
+			st->ss->getinfo_super(st, &info, NULL);
+			if (bestsuper == -1 ||
+			    besttime < info.array.ctime) {
+				bestsuper = i;
+				besttime = info.array.ctime;
+			}
+			ss->free_super(st);
+		}
+	}
+	if (bestsuper != -1) {
+		int rv;
+		memset(st, 0, sizeof(*st));
+		st->ignore_hw_compat = 1;
+		rv = superlist[bestsuper]->load_super(st, fd, NULL);
+		if (rv == 0) {
+			superlist[bestsuper]->free_super(st);
+			return st;
+		}
+	}
+	free(st);
+	return NULL;
+}
+
+/* Return size of device in bytes */
+int get_dev_size(int fd, char *dname, unsigned long long *sizep)
+{
+	unsigned long long ldsize;
+	struct stat st;
+
+	if (fstat(fd, &st) != -1 && S_ISREG(st.st_mode))
+		ldsize = (unsigned long long)st.st_size;
+	else
+#ifdef BLKGETSIZE64
+	if (ioctl(fd, BLKGETSIZE64, &ldsize) != 0)
+#endif
+	{
+		unsigned long dsize;
+		if (ioctl(fd, BLKGETSIZE, &dsize) == 0) {
+			ldsize = dsize;
+			ldsize <<= 9;
+		} else {
+			if (dname)
+				pr_err("Cannot get size of %s: %s\n",
+					dname, strerror(errno));
+			return 0;
+		}
+	}
+	*sizep = ldsize;
+	return 1;
+}
+
+/* Return sector size of device in bytes */
+int get_dev_sector_size(int fd, char *dname, unsigned int *sectsizep)
+{
+	unsigned int sectsize;
+
+	if (ioctl(fd, BLKSSZGET, &sectsize) != 0) {
+		if (dname)
+			pr_err("Cannot get sector size of %s: %s\n",
+				dname, strerror(errno));
+		return 0;
+	}
+
+	*sectsizep = sectsize;
+	return 1;
+}
+
+/* Return true if this can only be a container, not a member device.
+ * i.e. is and md device and size is zero
+ */
+int must_be_container(int fd)
+{
+	struct mdinfo *mdi;
+	unsigned long long size;
+
+	mdi = sysfs_read(fd, NULL, GET_VERSION);
+	if (!mdi)
+		return 0;
+	sysfs_free(mdi);
+
+	if (get_dev_size(fd, NULL, &size) == 0)
+		return 1;
+	if (size == 0)
+		return 1;
+	return 0;
+}
+
+/* Sets endofpart parameter to the last block used by the last GPT partition on the device.
+ * Returns: 1 if successful
+ *         -1 for unknown partition type
+ *          0 for other errors
+ */
+static int get_gpt_last_partition_end(int fd, unsigned long long *endofpart)
+{
+	struct GPT gpt;
+	unsigned char empty_gpt_entry[16]= {0};
+	struct GPT_part_entry *part;
+	char buf[512];
+	unsigned long long curr_part_end;
+	unsigned all_partitions, entry_size;
+	unsigned part_nr;
+	unsigned int sector_size = 0;
+
+	*endofpart = 0;
+
+	BUILD_BUG_ON(sizeof(gpt) != 512);
+	/* skip protective MBR */
+	if (!get_dev_sector_size(fd, NULL, &sector_size))
+		return 0;
+	lseek(fd, sector_size, SEEK_SET);
+	/* read GPT header */
+	if (read(fd, &gpt, 512) != 512)
+		return 0;
+
+	/* get the number of partition entries and the entry size */
+	all_partitions = __le32_to_cpu(gpt.part_cnt);
+	entry_size = __le32_to_cpu(gpt.part_size);
+
+	/* Check GPT signature*/
+	if (gpt.magic != GPT_SIGNATURE_MAGIC)
+		return -1;
+
+	/* sanity checks */
+	if (all_partitions > 1024 ||
+	    entry_size > sizeof(buf))
+		return -1;
+
+	part = (struct GPT_part_entry *)buf;
+
+	/* set offset to third block (GPT entries) */
+	lseek(fd, sector_size*2, SEEK_SET);
+	for (part_nr = 0; part_nr < all_partitions; part_nr++) {
+		/* read partition entry */
+		if (read(fd, buf, entry_size) != (ssize_t)entry_size)
+			return 0;
+
+		/* is this valid partition? */
+		if (memcmp(part->type_guid, empty_gpt_entry, 16) != 0) {
+			/* check the last lba for the current partition */
+			curr_part_end = __le64_to_cpu(part->ending_lba);
+			if (curr_part_end > *endofpart)
+				*endofpart = curr_part_end;
+		}
+
+	}
+	return 1;
+}
+
+/* Sets endofpart parameter to the last block used by the last partition on the device.
+ * Returns: 1 if successful
+ *         -1 for unknown partition type
+ *          0 for other errors
+ */
+static int get_last_partition_end(int fd, unsigned long long *endofpart)
+{
+	struct MBR boot_sect;
+	unsigned long long curr_part_end;
+	unsigned part_nr;
+	unsigned int sector_size;
+	int retval = 0;
+
+	*endofpart = 0;
+
+	BUILD_BUG_ON(sizeof(boot_sect) != 512);
+	/* read MBR */
+	lseek(fd, 0, 0);
+	if (read(fd, &boot_sect, 512) != 512)
+		goto abort;
+
+	/* check MBP signature */
+	if (boot_sect.magic == MBR_SIGNATURE_MAGIC) {
+		retval = 1;
+		/* found the correct signature */
+
+		for (part_nr = 0; part_nr < MBR_PARTITIONS; part_nr++) {
+			/*
+			 * Have to make every access through boot_sect rather
+			 * than using a pointer to the partition table (or an
+			 * entry), since the entries are not properly aligned.
+			 */
+
+			/* check for GPT type */
+			if (boot_sect.parts[part_nr].part_type ==
+			    MBR_GPT_PARTITION_TYPE) {
+				retval = get_gpt_last_partition_end(fd, endofpart);
+				break;
+			}
+			/* check the last used lba for the current partition  */
+			curr_part_end =
+				__le32_to_cpu(boot_sect.parts[part_nr].first_sect_lba) +
+				__le32_to_cpu(boot_sect.parts[part_nr].blocks_num);
+			if (curr_part_end > *endofpart)
+				*endofpart = curr_part_end;
+		}
+	} else {
+		/* Unknown partition table */
+		retval = -1;
+	}
+	/* calculate number of 512-byte blocks */
+	if (get_dev_sector_size(fd, NULL, &sector_size))
+		*endofpart *= (sector_size / 512);
+ abort:
+	return retval;
+}
+
+int check_partitions(int fd, char *dname, unsigned long long freesize,
+			unsigned long long size)
+{
+	/*
+	 * Check where the last partition ends
+	 */
+	unsigned long long endofpart;
+
+	if (get_last_partition_end(fd, &endofpart) > 0) {
+		/* There appears to be a partition table here */
+		if (freesize == 0) {
+			/* partitions will not be visible in new device */
+			pr_err("partition table exists on %s but will be lost or\n"
+			       "       meaningless after creating array\n",
+			       dname);
+			return 1;
+		} else if (endofpart > freesize) {
+			/* last partition overlaps metadata */
+			pr_err("metadata will over-write last partition on %s.\n",
+			       dname);
+			return 1;
+		} else if (size && endofpart > size) {
+			/* partitions will be truncated in new device */
+			pr_err("array size is too small to cover all partitions on %s.\n",
+			       dname);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+int open_container(int fd)
+{
+	/* 'fd' is a block device.  Find out if it is in use
+	 * by a container, and return an open fd on that container.
+	 */
+	char path[288];
+	char *e;
+	DIR *dir;
+	struct dirent *de;
+	int dfd, n;
+	char buf[200];
+	int major, minor;
+	struct stat st;
+
+	if (fstat(fd, &st) != 0)
+		return -1;
+	sprintf(path, "/sys/dev/block/%d:%d/holders",
+		(int)major(st.st_rdev), (int)minor(st.st_rdev));
+	e = path + strlen(path);
+
+	dir = opendir(path);
+	if (!dir)
+		return -1;
+	while ((de = readdir(dir))) {
+		if (de->d_ino == 0)
+			continue;
+		if (de->d_name[0] == '.')
+			continue;
+		/* Need to make sure it is a container and not a volume */
+		sprintf(e, "/%s/md/metadata_version", de->d_name);
+		dfd = open(path, O_RDONLY);
+		if (dfd < 0)
+			continue;
+		n = read(dfd, buf, sizeof(buf));
+		close(dfd);
+		if (n <= 0 || (unsigned)n >= sizeof(buf))
+			continue;
+		buf[n] = 0;
+		if (strncmp(buf, "external", 8) != 0 ||
+		    n < 10 ||
+		    buf[9] == '/')
+			continue;
+		sprintf(e, "/%s/dev", de->d_name);
+		dfd = open(path, O_RDONLY);
+		if (dfd < 0)
+			continue;
+		n = read(dfd, buf, sizeof(buf));
+		close(dfd);
+		if (n <= 0 || (unsigned)n >= sizeof(buf))
+			continue;
+		buf[n] = 0;
+		if (sscanf(buf, "%d:%d", &major, &minor) != 2)
+			continue;
+		sprintf(buf, "%d:%d", major, minor);
+		dfd = dev_open(buf, O_RDONLY);
+		if (dfd >= 0) {
+			closedir(dir);
+			return dfd;
+		}
+	}
+	closedir(dir);
+	return -1;
+}
+
+struct superswitch *version_to_superswitch(char *vers)
+{
+	int i;
+
+	for (i = 0; superlist[i]; i++) {
+		struct superswitch *ss = superlist[i];
+
+		if (strcmp(vers, ss->name) == 0)
+			return ss;
+	}
+
+	return NULL;
+}
+
+int metadata_container_matches(char *metadata, char *devnm)
+{
+	/* Check if 'devnm' is the container named in 'metadata'
+	 * which is
+	 *   /containername/componentname  or
+	 *   -containername/componentname
+	 */
+	int l;
+	if (*metadata != '/' && *metadata != '-')
+		return 0;
+	l = strlen(devnm);
+	if (strncmp(metadata+1, devnm, l) != 0)
+		return 0;
+	if (metadata[l+1] != '/')
+		return 0;
+	return 1;
+}
+
+int metadata_subdev_matches(char *metadata, char *devnm)
+{
+	/* Check if 'devnm' is the subdev named in 'metadata'
+	 * which is
+	 *   /containername/subdev  or
+	 *   -containername/subdev
+	 */
+	char *sl;
+	if (*metadata != '/' && *metadata != '-')
+		return 0;
+	sl = strchr(metadata+1, '/');
+	if (!sl)
+		return 0;
+	if (strcmp(sl+1, devnm) == 0)
+		return 1;
+	return 0;
+}
+
+int is_container_member(struct mdstat_ent *mdstat, char *container)
+{
+	if (mdstat->metadata_version == NULL ||
+	    strncmp(mdstat->metadata_version, "external:", 9) != 0 ||
+	    !metadata_container_matches(mdstat->metadata_version+9, container))
+		return 0;
+
+	return 1;
+}
+
+int is_subarray_active(char *subarray, char *container)
+{
+	struct mdstat_ent *mdstat = mdstat_read(0, 0);
+	struct mdstat_ent *ent;
+
+	for (ent = mdstat; ent; ent = ent->next)
+		if (is_container_member(ent, container))
+			if (strcmp(to_subarray(ent, container), subarray) == 0)
+				break;
+
+	free_mdstat(mdstat);
+
+	return ent != NULL;
+}
+
+/* open_subarray - opens a subarray in a container
+ * @dev: container device name
+ * @st: empty supertype
+ * @quiet: block reporting errors flag
+ *
+ * On success returns an fd to a container and fills in *st
+ */
+int open_subarray(char *dev, char *subarray, struct supertype *st, int quiet)
+{
+	struct mdinfo *mdi;
+	struct mdinfo *info;
+	int fd, err = 1;
+	char *_devnm;
+
+	fd = open(dev, O_RDWR|O_EXCL);
+	if (fd < 0) {
+		if (!quiet)
+			pr_err("Couldn't open %s, aborting\n",
+				dev);
+		return -1;
+	}
+
+	_devnm = fd2devnm(fd);
+	if (_devnm == NULL) {
+		if (!quiet)
+			pr_err("Failed to determine device number for %s\n",
+			       dev);
+		goto close_fd;
+	}
+	strcpy(st->devnm, _devnm);
+
+	mdi = sysfs_read(fd, st->devnm, GET_VERSION|GET_LEVEL);
+	if (!mdi) {
+		if (!quiet)
+			pr_err("Failed to read sysfs for %s\n",
+				dev);
+		goto close_fd;
+	}
+
+	if (mdi->array.level != UnSet) {
+		if (!quiet)
+			pr_err("%s is not a container\n", dev);
+		goto free_sysfs;
+	}
+
+	st->ss = version_to_superswitch(mdi->text_version);
+	if (!st->ss) {
+		if (!quiet)
+			pr_err("Operation not supported for %s metadata\n",
+			       mdi->text_version);
+		goto free_sysfs;
+	}
+
+	if (st->devnm[0] == 0) {
+		if (!quiet)
+			pr_err("Failed to allocate device name\n");
+		goto free_sysfs;
+	}
+
+	if (!st->ss->load_container) {
+		if (!quiet)
+			pr_err("%s is not a container\n", dev);
+		goto free_sysfs;
+	}
+
+	if (st->ss->load_container(st, fd, NULL)) {
+		if (!quiet)
+			pr_err("Failed to load metadata for %s\n",
+				dev);
+		goto free_sysfs;
+	}
+
+	info = st->ss->container_content(st, subarray);
+	if (!info) {
+		if (!quiet)
+			pr_err("Failed to find subarray-%s in %s\n",
+				subarray, dev);
+		goto free_super;
+	}
+	free(info);
+
+	err = 0;
+
+ free_super:
+	if (err)
+		st->ss->free_super(st);
+ free_sysfs:
+	sysfs_free(mdi);
+ close_fd:
+	if (err)
+		close(fd);
+
+	if (err)
+		return -1;
+	else
+		return fd;
+}
+
+int add_disk(int mdfd, struct supertype *st,
+	     struct mdinfo *sra, struct mdinfo *info)
+{
+	/* Add a device to an array, in one of 2 ways. */
+	int rv;
+
+	if (st->ss->external) {
+		if (info->disk.state & (1<<MD_DISK_SYNC))
+			info->recovery_start = MaxSector;
+		else
+			info->recovery_start = 0;
+		rv = sysfs_add_disk(sra, info, 0);
+		if (! rv) {
+			struct mdinfo *sd2;
+			for (sd2 = sra->devs; sd2; sd2=sd2->next)
+				if (sd2 == info)
+					break;
+			if (sd2 == NULL) {
+				sd2 = xmalloc(sizeof(*sd2));
+				*sd2 = *info;
+				sd2->next = sra->devs;
+				sra->devs = sd2;
+			}
+		}
+	} else
+		rv = ioctl(mdfd, ADD_NEW_DISK, &info->disk);
+	return rv;
+}
+
+int remove_disk(int mdfd, struct supertype *st,
+		struct mdinfo *sra, struct mdinfo *info)
+{
+	int rv;
+
+	/* Remove the disk given by 'info' from the array */
+	if (st->ss->external)
+		rv = sysfs_set_str(sra, info, "slot", "none");
+	else
+		rv = ioctl(mdfd, HOT_REMOVE_DISK, makedev(info->disk.major,
+							  info->disk.minor));
+	return rv;
+}
+
+int hot_remove_disk(int mdfd, unsigned long dev, int force)
+{
+	int cnt = force ? 500 : 5;
+	int ret;
+
+	/* HOT_REMOVE_DISK can fail with EBUSY if there are
+	 * outstanding IO requests to the device.
+	 * In this case, it can be helpful to wait a little while,
+	 * up to 5 seconds if 'force' is set, or 50 msec if not.
+	 */
+	while ((ret = ioctl(mdfd, HOT_REMOVE_DISK, dev)) == -1 &&
+	       errno == EBUSY &&
+	       cnt-- > 0)
+		usleep(10000);
+
+	return ret;
+}
+
+int sys_hot_remove_disk(int statefd, int force)
+{
+	int cnt = force ? 500 : 5;
+	int ret;
+
+	while ((ret = write(statefd, "remove", 6)) == -1 &&
+	       errno == EBUSY &&
+	       cnt-- > 0)
+		usleep(10000);
+	return ret == 6 ? 0 : -1;
+}
+
+int set_array_info(int mdfd, struct supertype *st, struct mdinfo *info)
+{
+	/* Initialise kernel's knowledge of array.
+	 * This varies between externally managed arrays
+	 * and older kernels
+	 */
+	mdu_array_info_t inf;
+	int rv;
+
+	if (st->ss->external)
+		return sysfs_set_array(info, 9003);
+		
+	memset(&inf, 0, sizeof(inf));
+	inf.major_version = info->array.major_version;
+	inf.minor_version = info->array.minor_version;
+	rv = md_set_array_info(mdfd, &inf);
+
+	return rv;
+}
+
+unsigned long long min_recovery_start(struct mdinfo *array)
+{
+	/* find the minimum recovery_start in an array for metadata
+	 * formats that only record per-array recovery progress instead
+	 * of per-device
+	 */
+	unsigned long long recovery_start = MaxSector;
+	struct mdinfo *d;
+
+	for (d = array->devs; d; d = d->next)
+		recovery_start = min(recovery_start, d->recovery_start);
+
+	return recovery_start;
+}
+
+int mdmon_pid(char *devnm)
+{
+	char path[100];
+	char pid[10];
+	int fd;
+	int n;
+
+	sprintf(path, "%s/%s.pid", MDMON_DIR, devnm);
+
+	fd = open(path, O_RDONLY | O_NOATIME, 0);
+
+	if (fd < 0)
+		return -1;
+	n = read(fd, pid, 9);
+	close(fd);
+	if (n <= 0)
+		return -1;
+	return atoi(pid);
+}
+
+int mdmon_running(char *devnm)
+{
+	int pid = mdmon_pid(devnm);
+	if (pid <= 0)
+		return 0;
+	if (kill(pid, 0) == 0)
+		return 1;
+	return 0;
+}
+
+int start_mdmon(char *devnm)
+{
+	int i;
+	int len;
+	pid_t pid;
+	int status;
+	char pathbuf[1024];
+	char *paths[4] = {
+		pathbuf,
+		BINDIR "/mdmon",
+		"./mdmon",
+		NULL
+	};
+
+	if (check_env("MDADM_NO_MDMON"))
+		return 0;
+	if (continue_via_systemd(devnm, MDMON_SERVICE))
+		return 0;
+
+	/* That failed, try running mdmon directly */
+	len = readlink("/proc/self/exe", pathbuf, sizeof(pathbuf)-1);
+	if (len > 0) {
+		char *sl;
+		pathbuf[len] = 0;
+		sl = strrchr(pathbuf, '/');
+		if (sl)
+			sl++;
+		else
+			sl = pathbuf;
+		strcpy(sl, "mdmon");
+	} else
+		pathbuf[0] = '\0';
+
+	switch(fork()) {
+	case 0:
+		manage_fork_fds(1);
+		for (i = 0; paths[i]; i++)
+			if (paths[i][0]) {
+				execl(paths[i], paths[i],
+				      devnm, NULL);
+			}
+		exit(1);
+	case -1: pr_err("cannot run mdmon. Array remains readonly\n");
+		return -1;
+	default: /* parent - good */
+		pid = wait(&status);
+		if (pid < 0 || status != 0) {
+			pr_err("failed to launch mdmon. Array remains readonly\n");
+			return -1;
+		}
+	}
+	return 0;
+}
+
+__u32 random32(void)
+{
+	__u32 rv;
+	int rfd = open("/dev/urandom", O_RDONLY);
+	if (rfd < 0 || read(rfd, &rv, 4) != 4)
+		rv = random();
+	if (rfd >= 0)
+		close(rfd);
+	return rv;
+}
+
+void random_uuid(__u8 *buf)
+{
+	int fd, i, len;
+	__u32 r[4];
+
+	fd = open("/dev/urandom", O_RDONLY);
+	if (fd < 0)
+		goto use_random;
+	len = read(fd, buf, 16);
+	close(fd);
+	if (len != 16)
+		goto use_random;
+
+	return;
+
+use_random:
+	for (i = 0; i < 4; i++)
+		r[i] = random();
+	memcpy(buf, r, 16);
+}
+
+int flush_metadata_updates(struct supertype *st)
+{
+	int sfd;
+	if (!st->updates) {
+		st->update_tail = NULL;
+		return -1;
+	}
+
+	sfd = connect_monitor(st->container_devnm);
+	if (sfd < 0)
+		return -1;
+
+	while (st->updates) {
+		struct metadata_update *mu = st->updates;
+		st->updates = mu->next;
+
+		send_message(sfd, mu, 0);
+		wait_reply(sfd, 0);
+		free(mu->buf);
+		free(mu);
+	}
+	ack(sfd, 0);
+	wait_reply(sfd, 0);
+	close(sfd);
+	st->update_tail = NULL;
+	return 0;
+}
+
+void append_metadata_update(struct supertype *st, void *buf, int len)
+{
+
+	struct metadata_update *mu = xmalloc(sizeof(*mu));
+
+	mu->buf = buf;
+	mu->len = len;
+	mu->space = NULL;
+	mu->space_list = NULL;
+	mu->next = NULL;
+	*st->update_tail = mu;
+	st->update_tail = &mu->next;
+}
+
+#ifdef __TINYC__
+/* tinyc doesn't optimize this check in ioctl.h out ... */
+unsigned int __invalid_size_argument_for_IOC = 0;
+#endif
+
+/* Pick all spares matching given criteria from a container
+ * if min_size == 0 do not check size
+ * if domlist == NULL do not check domains
+ * if spare_group given add it to domains of each spare
+ * metadata allows to test domains using metadata of destination array */
+struct mdinfo *container_choose_spares(struct supertype *st,
+				       struct spare_criteria *criteria,
+				       struct domainlist *domlist,
+				       char *spare_group,
+				       const char *metadata, int get_one)
+{
+	struct mdinfo *d, **dp, *disks = NULL;
+
+	/* get list of all disks in container */
+	if (st->ss->getinfo_super_disks)
+		disks = st->ss->getinfo_super_disks(st);
+
+	if (!disks)
+		return disks;
+	/* find spare devices on the list */
+	dp = &disks->devs;
+	disks->array.spare_disks = 0;
+	while (*dp) {
+		int found = 0;
+		d = *dp;
+		if (d->disk.state == 0) {
+			/* check if size is acceptable */
+			unsigned long long dev_size;
+			unsigned int dev_sector_size;
+			int size_valid = 0;
+			int sector_size_valid = 0;
+
+			dev_t dev = makedev(d->disk.major,d->disk.minor);
+
+			if (!criteria->min_size ||
+			   (dev_size_from_id(dev,  &dev_size) &&
+			    dev_size >= criteria->min_size))
+				size_valid = 1;
+
+			if (!criteria->sector_size ||
+			    (dev_sector_size_from_id(dev, &dev_sector_size) &&
+			     criteria->sector_size == dev_sector_size))
+				sector_size_valid = 1;
+
+			found = size_valid && sector_size_valid;
+
+			/* check if domain matches */
+			if (found && domlist) {
+				struct dev_policy *pol = devid_policy(dev);
+				if (spare_group)
+					pol_add(&pol, pol_domain,
+						spare_group, NULL);
+				if (domain_test(domlist, pol, metadata) != 1)
+					found = 0;
+				dev_policy_free(pol);
+			}
+		}
+		if (found) {
+			dp = &d->next;
+			disks->array.spare_disks++;
+			if (get_one) {
+				sysfs_free(*dp);
+				d->next = NULL;
+			}
+		} else {
+			*dp = d->next;
+			d->next = NULL;
+			sysfs_free(d);
+		}
+	}
+	return disks;
+}
+
+/* Checks if paths point to the same device
+ * Returns 0 if they do.
+ * Returns 1 if they don't.
+ * Returns -1 if something went wrong,
+ * e.g. paths are empty or the files
+ * they point to don't exist */
+int compare_paths (char* path1, char* path2)
+{
+	struct stat st1,st2;
+
+	if (path1 == NULL || path2 == NULL)
+		return -1;
+	if (stat(path1,&st1) != 0)
+		return -1;
+	if (stat(path2,&st2) != 0)
+		return -1;
+	if ((st1.st_ino == st2.st_ino) && (st1.st_dev == st2.st_dev))
+		return 0;
+	return 1;
+}
+
+/* Make sure we can open as many devices as needed */
+void enable_fds(int devices)
+{
+	unsigned int fds = 20 + devices;
+	struct rlimit lim;
+	if (getrlimit(RLIMIT_NOFILE, &lim) != 0 || lim.rlim_cur >= fds)
+		return;
+	if (lim.rlim_max < fds)
+		lim.rlim_max = fds;
+	lim.rlim_cur = fds;
+	setrlimit(RLIMIT_NOFILE, &lim);
+}
+
+/* Close all opened descriptors if needed and redirect
+ * streams to /dev/null.
+ * For debug purposed, leave STDOUT and STDERR untouched
+ * Returns:
+ *	1- if any error occurred
+ *	0- otherwise
+ */
+void manage_fork_fds(int close_all)
+{
+	DIR *dir;
+	struct dirent *dirent;
+
+	close(0);
+	open("/dev/null", O_RDWR);
+
+#ifndef DEBUG
+	dup2(0, 1);
+	dup2(0, 2);
+#endif
+
+	if (close_all == 0)
+		return;
+
+	dir = opendir("/proc/self/fd");
+	if (!dir) {
+		pr_err("Cannot open /proc/self/fd directory.\n");
+		return;
+	}
+	for (dirent = readdir(dir); dirent; dirent = readdir(dir)) {
+		int fd = -1;
+
+		if ((strcmp(dirent->d_name, ".") == 0) ||
+		    (strcmp(dirent->d_name, "..")) == 0)
+			continue;
+
+		fd = strtol(dirent->d_name, NULL, 10);
+		if (fd > 2)
+			close(fd);
+	}
+}
+
+/* In a systemd/udev world, it is best to get systemd to
+ * run daemon rather than running in the background.
+ * Returns:
+ *	1- if systemd service has been started
+ *	0- otherwise
+ */
+int continue_via_systemd(char *devnm, char *service_name)
+{
+	int pid, status;
+	char pathbuf[1024];
+
+	/* Simply return that service cannot be started */
+	if (check_env("MDADM_NO_SYSTEMCTL"))
+		return 0;
+	switch (fork()) {
+	case  0:
+		manage_fork_fds(1);
+		snprintf(pathbuf, sizeof(pathbuf),
+			 "%s@%s.service", service_name, devnm);
+		status = execl("/usr/bin/systemctl", "systemctl", "restart",
+			       pathbuf, NULL);
+		status = execl("/bin/systemctl", "systemctl", "restart",
+			       pathbuf, NULL);
+		exit(1);
+	case -1: /* Just do it ourselves. */
+		break;
+	default: /* parent - good */
+		pid = wait(&status);
+		if (pid >= 0 && status == 0)
+			return 1;
+	}
+	return 0;
+}
+
+int in_initrd(void)
+{
+	/* This is based on similar function in systemd. */
+	struct statfs s;
+	/* statfs.f_type is signed long on s390x and MIPS, causing all
+	   sorts of sign extension problems with RAMFS_MAGIC being
+	   defined as 0x858458f6 */
+	return  statfs("/", &s) >= 0 &&
+		((unsigned long)s.f_type == TMPFS_MAGIC ||
+		 ((unsigned long)s.f_type & 0xFFFFFFFFUL) ==
+		 ((unsigned long)RAMFS_MAGIC & 0xFFFFFFFFUL));
+}
+
+void reopen_mddev(int mdfd)
+{
+	/* Re-open without any O_EXCL, but keep
+	 * the same fd
+	 */
+	char *devnm;
+	int fd;
+	devnm = fd2devnm(mdfd);
+	close(mdfd);
+	fd = open_dev(devnm);
+	if (fd >= 0 && fd != mdfd)
+		dup2(fd, mdfd);
+}
+
+static struct cmap_hooks *cmap_hooks = NULL;
+static int is_cmap_hooks_ready = 0;
+
+void set_cmap_hooks(void)
+{
+	cmap_hooks = xmalloc(sizeof(struct cmap_hooks));
+	cmap_hooks->cmap_handle = dlopen("libcmap.so.4", RTLD_NOW | RTLD_LOCAL);
+	if (!cmap_hooks->cmap_handle)
+		return;
+
+	cmap_hooks->initialize =
+		dlsym(cmap_hooks->cmap_handle, "cmap_initialize");
+	cmap_hooks->get_string =
+		dlsym(cmap_hooks->cmap_handle, "cmap_get_string");
+	cmap_hooks->finalize = dlsym(cmap_hooks->cmap_handle, "cmap_finalize");
+
+	if (!cmap_hooks->initialize || !cmap_hooks->get_string ||
+	    !cmap_hooks->finalize)
+		dlclose(cmap_hooks->cmap_handle);
+	else
+		is_cmap_hooks_ready = 1;
+}
+
+int get_cluster_name(char **cluster_name)
+{
+        int rv = -1;
+	cmap_handle_t handle;
+
+	if (!is_cmap_hooks_ready)
+		return rv;
+
+        rv = cmap_hooks->initialize(&handle);
+        if (rv != CS_OK)
+                goto out;
+
+        rv = cmap_hooks->get_string(handle, "totem.cluster_name", cluster_name);
+        if (rv != CS_OK) {
+                free(*cluster_name);
+                rv = -1;
+                goto name_err;
+        }
+
+        rv = 0;
+name_err:
+        cmap_hooks->finalize(handle);
+out:
+        return rv;
+}
+
+void set_dlm_hooks(void)
+{
+	dlm_hooks = xmalloc(sizeof(struct dlm_hooks));
+	dlm_hooks->dlm_handle = dlopen("libdlm_lt.so.3", RTLD_NOW | RTLD_LOCAL);
+	if (!dlm_hooks->dlm_handle)
+		return;
+
+	dlm_hooks->open_lockspace =
+		dlsym(dlm_hooks->dlm_handle, "dlm_open_lockspace");
+	dlm_hooks->create_lockspace =
+		dlsym(dlm_hooks->dlm_handle, "dlm_create_lockspace");
+	dlm_hooks->release_lockspace =
+		dlsym(dlm_hooks->dlm_handle, "dlm_release_lockspace");
+	dlm_hooks->ls_lock = dlsym(dlm_hooks->dlm_handle, "dlm_ls_lock");
+	dlm_hooks->ls_unlock_wait =
+		dlsym(dlm_hooks->dlm_handle, "dlm_ls_unlock_wait");
+	dlm_hooks->ls_get_fd = dlsym(dlm_hooks->dlm_handle, "dlm_ls_get_fd");
+	dlm_hooks->dispatch = dlsym(dlm_hooks->dlm_handle, "dlm_dispatch");
+
+	if (!dlm_hooks->open_lockspace || !dlm_hooks->create_lockspace ||
+	    !dlm_hooks->ls_lock || !dlm_hooks->ls_unlock_wait ||
+	    !dlm_hooks->release_lockspace || !dlm_hooks->ls_get_fd ||
+	    !dlm_hooks->dispatch)
+		dlclose(dlm_hooks->dlm_handle);
+	else
+		is_dlm_hooks_ready = 1;
+}
+
+void set_hooks(void)
+{
+	set_dlm_hooks();
+	set_cmap_hooks();
+}
+
+int zero_disk_range(int fd, unsigned long long sector, size_t count)
+{
+	int ret = 0;
+	int fd_zero;
+	void *addr = NULL;
+	size_t written = 0;
+	size_t len = count * 512;
+	ssize_t n;
+
+	fd_zero = open("/dev/zero", O_RDONLY);
+	if (fd_zero < 0) {
+		pr_err("Cannot open /dev/zero\n");
+		return -1;
+	}
+
+	if (lseek64(fd, sector * 512, SEEK_SET) < 0) {
+		ret = -errno;
+		pr_err("Failed to seek offset for zeroing\n");
+		goto out;
+	}
+
+	addr = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd_zero, 0);
+
+	if (addr == MAP_FAILED) {
+		ret = -errno;
+		pr_err("Mapping /dev/zero failed\n");
+		goto out;
+	}
+
+	do {
+		n = write(fd, addr + written, len - written);
+		if (n < 0) {
+			if (errno == EINTR)
+				continue;
+			ret = -errno;
+			pr_err("Zeroing disk range failed\n");
+			break;
+		}
+		written += n;
+	} while (written != len);
+
+	munmap(addr, len);
+
+out:
+	close(fd_zero);
+	return ret;
+}