[PATCH] extras/multipath update

here is the next update which brings this multipath to the state i'm not
ashamed of it being in udev :)

* drop a libdevmapper copy in extras/multipath; maybe discussions w/
Sistina folks will bring a better solution in the future.
* drop a putchar usage in libdevmapper to compile cleanly with klibc
* drop another such usage of my own in main.c
* massage the Makefile to compile libdevmapper against klibc
* use "ld" to produce the binary rather than "gcc -static"
* stop being stupid w/ uneeded major, minor & dev in main.c:dm_mk_node()
* reverse to creating striped target for now because the multipath
target is more hairy than expected initialy
* push the version code to 009 to be in synch w/ udev

builds & run here.
binary size is 43ko, which is fairly gratifying after all the efforts
I've put to compiling it with klibc :)

8 files changed, 1935 insertions, 0 deletions

diff --git a/extras/multipath/libdevmapper/Makefile b/extras/multipath/libdevmapper/Makefile
new file mode 100644
index 0000000000..72b39cedf5
--- /dev/null
+++ b/extras/multipath/libdevmapper/Makefile
@@ -0,0 +1,15 @@
+# Makefile
+#
+# Copyright (C) 2003 Christophe Varoqui, <christophe.varoqui@free.fr>
+
+CC = gcc
+CFLAGS = -pipe -g -O2 -Wall -Wunused -Wstrict-prototypes -nostdinc -I../../../klibc/klibc/include -I../../../klibc/klibc/include/bits32 -I/usr/lib/gcc-lib/i586-mandrake-linux-gnu/3.3.1/include -I../../../klibc/linux/include -I. -Iioctl
+
+OBJS = ioctl/libdevmapper.o libdm-common.o
+
+all:	$(OBJS)
+	@echo ""
+	@echo "Make complete"
+
+clean:
+	rm -f core *.o ioctl/*.o ioctl/*.so
diff --git a/extras/multipath/libdevmapper/ioctl/libdevmapper.c b/extras/multipath/libdevmapper/ioctl/libdevmapper.c
new file mode 100644
index 0000000000..ac7ba0c86a
--- /dev/null
+++ b/extras/multipath/libdevmapper/ioctl/libdevmapper.c
@@ -0,0 +1,1092 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#include "libdm-targets.h"
+#include "libdm-common.h"
+
+#ifdef DM_COMPAT
+#  include "libdm-compat.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <limits.h>
+
+#ifdef linux
+#  include <linux/limits.h>
+#  include <linux/kdev_t.h>
+#  include <linux/dm-ioctl.h>
+#else
+#  define MAJOR(x) major((x))
+#  define MINOR(x) minor((x))
+#  define MKDEV(x,y) makedev((x),(y))
+#endif
+
+/*
+ * Ensure build compatibility.  
+ * The hard-coded versions here are the highest present 
+ * in the _cmd_data arrays.
+ */
+
+#if !((DM_VERSION_MAJOR == 1 && DM_VERSION_MINOR >= 0) || \
+      (DM_VERSION_MAJOR == 4 && DM_VERSION_MINOR >= 0))
+#error The version of dm-ioctl.h included is incompatible.
+#endif
+
+/* dm major version no for running kernel */
+static int _dm_version = DM_VERSION_MAJOR;
+static int _log_suppress = 0;
+
+static int _control_fd = -1;
+static int _version_checked = 0;
+static int _version_ok = 1;
+
+/*
+ * Support both old and new major numbers to ease the transition.
+ * Clumsy, but only temporary.
+ */
+#if DM_VERSION_MAJOR == 4 && defined(DM_COMPAT)
+const int _dm_compat = 1;
+#else
+const int _dm_compat = 0;
+#endif
+
+
+/* *INDENT-OFF* */
+static struct cmd_data _cmd_data_v4[] = {
+	{"create",	DM_DEV_CREATE,		{4, 0, 0}},
+	{"reload",	DM_TABLE_LOAD,		{4, 0, 0}},
+	{"remove",	DM_DEV_REMOVE,		{4, 0, 0}},
+	{"remove_all",	DM_REMOVE_ALL,		{4, 0, 0}},
+	{"suspend",	DM_DEV_SUSPEND,		{4, 0, 0}},
+	{"resume",	DM_DEV_SUSPEND,		{4, 0, 0}},
+	{"info",	DM_DEV_STATUS,		{4, 0, 0}},
+	{"deps",	DM_TABLE_DEPS,		{4, 0, 0}},
+	{"rename",	DM_DEV_RENAME,		{4, 0, 0}},
+	{"version",	DM_VERSION,		{4, 0, 0}},
+	{"status",	DM_TABLE_STATUS,	{4, 0, 0}},
+	{"table",	DM_TABLE_STATUS,	{4, 0, 0}},
+	{"waitevent",	DM_DEV_WAIT,		{4, 0, 0}},
+	{"names",	DM_LIST_DEVICES,	{4, 0, 0}},
+	{"clear",	DM_TABLE_CLEAR,		{4, 0, 0}},
+	{"mknodes",	DM_DEV_STATUS,		{4, 0, 0}},
+};
+/* *INDENT-ON* */
+
+#define ALIGNMENT_V1 sizeof(int)
+#define ALIGNMENT 8
+
+/* FIXME Rejig library to record & use errno instead */
+#ifndef DM_EXISTS_FLAG
+#  define DM_EXISTS_FLAG 0x00000004
+#endif
+
+static void *_align(void *ptr, unsigned int a)
+{
+	register unsigned long agn = --a;
+
+	return (void *) (((unsigned long) ptr + agn) & ~agn);
+}
+
+static int _open_control(void)
+{
+	char control[PATH_MAX];
+
+	if (_control_fd != -1)
+		return 1;
+
+	snprintf(control, sizeof(control), "%s/control", dm_dir());
+
+	if ((_control_fd = open(control, O_RDWR)) < 0) {
+		log_error("%s: open failed: %s", control, strerror(errno));
+		log_error("Is device-mapper driver missing from kernel?");
+		return 0;
+	}
+
+	return 1;
+}
+
+void dm_task_destroy(struct dm_task *dmt)
+{
+	struct target *t, *n;
+
+	for (t = dmt->head; t; t = n) {
+		n = t->next;
+		free(t->params);
+		free(t->type);
+		free(t);
+	}
+
+	if (dmt->dev_name)
+		free(dmt->dev_name);
+
+	if (dmt->newname)
+		free(dmt->newname);
+
+	if (dmt->dmi.v4)
+		free(dmt->dmi.v4);
+
+	if (dmt->uuid)
+		free(dmt->uuid);
+
+	free(dmt);
+}
+
+/*
+ * Protocol Version 1 compatibility functions.
+ */
+
+#ifdef DM_COMPAT
+
+static int _dm_task_get_driver_version_v1(struct dm_task *dmt, char *version,
+					  size_t size)
+{
+	unsigned int *v;
+
+	if (!dmt->dmi.v1) {
+		version[0] = '\0';
+		return 0;
+	}
+
+	v = dmt->dmi.v1->version;
+	snprintf(version, size, "%u.%u.%u", v[0], v[1], v[2]);
+	return 1;
+}
+
+/* Unmarshall the target info returned from a status call */
+static int _unmarshal_status_v1(struct dm_task *dmt, struct dm_ioctl_v1 *dmi)
+{
+	char *outbuf = (char *) dmi + dmi->data_start;
+	char *outptr = outbuf;
+	int32_t i;
+	struct dm_target_spec_v1 *spec;
+
+	for (i = 0; i < dmi->target_count; i++) {
+		spec = (struct dm_target_spec_v1 *) outptr;
+
+		if (!dm_task_add_target(dmt, spec->sector_start,
+					(uint64_t) spec->length,
+					spec->target_type,
+					outptr + sizeof(*spec)))
+			return 0;
+
+		outptr = outbuf + spec->next;
+	}
+
+	return 1;
+}
+
+static int _dm_format_dev_v1(char *buf, int bufsize, uint32_t dev_major,
+			     uint32_t dev_minor)
+{
+	int r;
+
+	if (bufsize < 8)
+		return 0;
+
+	r = snprintf(buf, bufsize, "%03x:%03x", dev_major, dev_minor);
+	if (r < 0 || r > bufsize - 1)
+		return 0;
+
+	return 1;
+}
+
+static int _dm_task_get_info_v1(struct dm_task *dmt, struct dm_info *info)
+{
+	if (!dmt->dmi.v1)
+		return 0;
+
+	memset(info, 0, sizeof(*info));
+
+	info->exists = dmt->dmi.v1->flags & DM_EXISTS_FLAG ? 1 : 0;
+	if (!info->exists)
+		return 1;
+
+	info->suspended = dmt->dmi.v1->flags & DM_SUSPEND_FLAG ? 1 : 0;
+	info->read_only = dmt->dmi.v1->flags & DM_READONLY_FLAG ? 1 : 0;
+	info->target_count = dmt->dmi.v1->target_count;
+	info->open_count = dmt->dmi.v1->open_count;
+	info->event_nr = 0;
+	info->major = MAJOR(dmt->dmi.v1->dev);
+	info->minor = MINOR(dmt->dmi.v1->dev);
+	info->live_table = 1;
+	info->inactive_table = 0;
+
+	return 1;
+}
+
+static const char *_dm_task_get_name_v1(struct dm_task *dmt)
+{
+	return (dmt->dmi.v1->name);
+}
+
+static const char *_dm_task_get_uuid_v1(struct dm_task *dmt)
+{
+	return (dmt->dmi.v1->uuid);
+}
+
+static struct dm_deps *_dm_task_get_deps_v1(struct dm_task *dmt)
+{
+	log_error("deps version 1 no longer supported by libdevmapper");
+	return NULL;
+}
+
+static struct dm_names *_dm_task_get_names_v1(struct dm_task *dmt)
+{
+	return (struct dm_names *) (((void *) dmt->dmi.v1) +
+				    dmt->dmi.v1->data_start);
+}
+
+static void *_add_target_v1(struct target *t, void *out, void *end)
+{
+	void *out_sp = out;
+	struct dm_target_spec_v1 sp;
+	size_t sp_size = sizeof(struct dm_target_spec_v1);
+	int len;
+	const char no_space[] = "Ran out of memory building ioctl parameter";
+
+	out += sp_size;
+	if (out >= end) {
+		log_error(no_space);
+		return NULL;
+	}
+
+	sp.status = 0;
+	sp.sector_start = t->start;
+	sp.length = t->length;
+	strncpy(sp.target_type, t->type, sizeof(sp.target_type));
+
+	len = strlen(t->params);
+
+	if ((out + len + 1) >= end) {
+		log_error(no_space);
+
+		log_error("t->params= '%s'", t->params);
+		return NULL;
+	}
+	strcpy((char *) out, t->params);
+	out += len + 1;
+
+	/* align next block */
+	out = _align(out, ALIGNMENT_V1);
+
+	sp.next = out - out_sp;
+
+	memcpy(out_sp, &sp, sp_size);
+
+	return out;
+}
+
+static struct dm_ioctl_v1 *_flatten_v1(struct dm_task *dmt)
+{
+	const size_t min_size = 16 * 1024;
+	const int (*version)[3];
+
+	struct dm_ioctl_v1 *dmi;
+	struct target *t;
+	size_t len = sizeof(struct dm_ioctl_v1);
+	void *b, *e;
+	int count = 0;
+
+	for (t = dmt->head; t; t = t->next) {
+		len += sizeof(struct dm_target_spec_v1);
+		len += strlen(t->params) + 1 + ALIGNMENT_V1;
+		count++;
+	}
+
+	if (count && dmt->newname) {
+		log_error("targets and newname are incompatible");
+		return NULL;
+	}
+
+	if (dmt->newname)
+		len += strlen(dmt->newname) + 1;
+
+	/*
+	 * Give len a minimum size so that we have space to store
+	 * dependencies or status information.
+	 */
+	if (len < min_size)
+		len = min_size;
+
+	if (!(dmi = malloc(len)))
+		return NULL;
+
+	memset(dmi, 0, len);
+
+	version = &_cmd_data_v1[dmt->type].version;
+
+	dmi->version[0] = (*version)[0];
+	dmi->version[1] = (*version)[1];
+	dmi->version[2] = (*version)[2];
+
+	dmi->data_size = len;
+	dmi->data_start = sizeof(struct dm_ioctl_v1);
+
+	if (dmt->dev_name)
+		strncpy(dmi->name, dmt->dev_name, sizeof(dmi->name));
+
+	if (dmt->type == DM_DEVICE_SUSPEND)
+		dmi->flags |= DM_SUSPEND_FLAG;
+	if (dmt->read_only)
+		dmi->flags |= DM_READONLY_FLAG;
+
+	if (dmt->minor >= 0) {
+		if (dmt->major <= 0) {
+			log_error("Missing major number for persistent device");
+			return NULL;
+		}
+		dmi->flags |= DM_PERSISTENT_DEV_FLAG;
+		dmi->dev = MKDEV(dmt->major, dmt->minor);
+	}
+
+	if (dmt->uuid)
+		strncpy(dmi->uuid, dmt->uuid, sizeof(dmi->uuid));
+
+	dmi->target_count = count;
+
+	b = (void *) (dmi + 1);
+	e = (void *) ((char *) dmi + len);
+
+	for (t = dmt->head; t; t = t->next)
+		if (!(b = _add_target_v1(t, b, e)))
+			goto bad;
+
+	if (dmt->newname)
+		strcpy(b, dmt->newname);
+
+	return dmi;
+
+      bad:
+	free(dmi);
+	return NULL;
+}
+
+static int _dm_names_v1(struct dm_ioctl_v1 *dmi)
+{
+	const char *dev_dir = dm_dir();
+	int r = 1, len;
+	const char *name;
+	struct dirent *dirent;
+	DIR *d;
+	struct dm_names *names, *old_names = NULL;
+	void *end = (void *) dmi + dmi->data_size;
+	struct stat buf;
+	char path[PATH_MAX];
+
+	if (!(d = opendir(dev_dir))) {
+		log_error("%s: opendir failed: %s", dev_dir, strerror(errno));
+		return 0;
+	}
+
+	names = (struct dm_names *) ((void *) dmi + dmi->data_start);
+
+	names->dev = 0;		/* Flags no data */
+
+	while ((dirent = readdir(d))) {
+		name = dirent->d_name;
+
+		if (name[0] == '.' || !strcmp(name, "control"))
+			continue;
+
+		if (old_names)
+			old_names->next = (uint32_t) ((void *) names -
+						      (void *) old_names);
+		snprintf(path, sizeof(path), "%s/%s", dev_dir, name);
+		if (stat(path, &buf)) {
+			log_error("%s: stat failed: %s", path, strerror(errno));
+			continue;
+		}
+		if (!S_ISBLK(buf.st_mode))
+			continue;
+		names->dev = (uint64_t) buf.st_rdev;
+		names->next = 0;
+		len = strlen(name);
+		if (((void *) (names + 1) + len + 1) >= end) {
+			log_error("Insufficient buffer space for device list");
+			r = 0;
+			break;
+		}
+
+		strcpy(names->name, name);
+
+		old_names = names;
+		names = _align((void *) ++names + len + 1, ALIGNMENT);
+	}
+
+	if (closedir(d))
+		log_error("%s: closedir failed: %s", dev_dir, strerror(errno));
+
+	return r;
+}
+
+static int _dm_task_run_v1(struct dm_task *dmt)
+{
+	struct dm_ioctl_v1 *dmi;
+	unsigned int command;
+
+	dmi = _flatten_v1(dmt);
+	if (!dmi) {
+		log_error("Couldn't create ioctl argument");
+		return 0;
+	}
+
+	if (!_open_control())
+		return 0;
+
+	if ((unsigned) dmt->type >=
+	    (sizeof(_cmd_data_v1) / sizeof(*_cmd_data_v1))) {
+		log_error("Internal error: unknown device-mapper task %d",
+			  dmt->type);
+		goto bad;
+	}
+
+	command = _cmd_data_v1[dmt->type].cmd;
+
+	if (dmt->type == DM_DEVICE_TABLE)
+		dmi->flags |= DM_STATUS_TABLE_FLAG;
+
+	log_debug("dm %s %s %s %s", _cmd_data_v1[dmt->type].name, dmi->name,
+		  dmi->uuid, dmt->newname ? dmt->newname : "");
+	if (dmt->type == DM_DEVICE_LIST) {
+		if (!_dm_names_v1(dmi))
+			goto bad;
+	} else if (ioctl(_control_fd, command, dmi) < 0) {
+		if (_log_suppress)
+			log_verbose("device-mapper ioctl cmd %d failed: %s",
+				    _IOC_NR(command), strerror(errno));
+		else
+			log_error("device-mapper ioctl cmd %d failed: %s",
+				  _IOC_NR(command), strerror(errno));
+		goto bad;
+	}
+
+	switch (dmt->type) {
+	case DM_DEVICE_CREATE:
+		add_dev_node(dmt->dev_name, MAJOR(dmi->dev), MINOR(dmi->dev));
+		break;
+
+	case DM_DEVICE_REMOVE:
+		rm_dev_node(dmt->dev_name);
+		break;
+
+	case DM_DEVICE_RENAME:
+		rename_dev_node(dmt->dev_name, dmt->newname);
+		break;
+
+	case DM_DEVICE_MKNODES:
+		if (dmi->flags & DM_EXISTS_FLAG)
+			add_dev_node(dmt->dev_name, MAJOR(dmi->dev),
+				     MINOR(dmi->dev));
+		else
+			rm_dev_node(dmt->dev_name);
+		break;
+
+	case DM_DEVICE_STATUS:
+	case DM_DEVICE_TABLE:
+		if (!_unmarshal_status_v1(dmt, dmi))
+			goto bad;
+		break;
+
+	case DM_DEVICE_SUSPEND:
+	case DM_DEVICE_RESUME:
+		dmt->type = DM_DEVICE_INFO;
+		if (!dm_task_run(dmt))
+			goto bad;
+		free(dmi);	/* We'll use what info returned */
+		return 1;
+	}
+
+	dmt->dmi.v1 = dmi;
+	return 1;
+
+      bad:
+	free(dmi);
+	return 0;
+}
+
+#endif
+
+/*
+ * Protocol Version 4 functions.
+ */
+
+int dm_task_get_driver_version(struct dm_task *dmt, char *version, size_t size)
+{
+	unsigned int *v;
+
+#ifdef DM_COMPAT
+	if (_dm_version == 1)
+		return _dm_task_get_driver_version_v1(dmt, version, size);
+#endif
+
+	if (!dmt->dmi.v4) {
+		version[0] = '\0';
+		return 0;
+	}
+
+	v = dmt->dmi.v4->version;
+	snprintf(version, size, "%u.%u.%u", v[0], v[1], v[2]);
+	return 1;
+}
+
+static int _check_version(char *version, size_t size, int log_suppress)
+{
+	struct dm_task *task;
+	int r;
+
+	if (!(task = dm_task_create(DM_DEVICE_VERSION))) {
+		log_error("Failed to get device-mapper version");
+		version[0] = '\0';
+		return 0;
+	}
+
+	if (log_suppress)
+		_log_suppress = 1;
+
+	r = dm_task_run(task);
+	dm_task_get_driver_version(task, version, size);
+	dm_task_destroy(task);
+	_log_suppress = 0;
+
+	return r;
+}
+
+/*
+ * Find out device-mapper's major version number the first time 
+ * this is called and whether or not we support it.
+ */
+int dm_check_version(void)
+{
+	char libversion[64], dmversion[64];
+	const char *compat = "";
+
+	if (_version_checked)
+		return _version_ok;
+
+	_version_checked = 1;
+
+	if (_check_version(dmversion, sizeof(dmversion), _dm_compat))
+		return 1;
+
+	if (!_dm_compat)
+		goto bad;
+
+	log_verbose("device-mapper ioctl protocol version %d failed. "
+		    "Trying protocol version 1.", _dm_version);
+	_dm_version = 1;
+	if (_check_version(dmversion, sizeof(dmversion), 0)) {
+		log_verbose("Using device-mapper ioctl protocol version 1");
+		return 1;
+	}
+
+	compat = "(compat)";
+
+	dm_get_library_version(libversion, sizeof(libversion));
+
+	log_error("Incompatible libdevmapper %s%s and kernel driver %s",
+		  libversion, compat, dmversion);
+
+      bad:
+	_version_ok = 0;
+	return 0;
+}
+
+void *dm_get_next_target(struct dm_task *dmt, void *next,
+			 uint64_t *start, uint64_t *length,
+			 char **target_type, char **params)
+{
+	struct target *t = (struct target *) next;
+
+	if (!t)
+		t = dmt->head;
+
+	if (!t)
+		return NULL;
+
+	*start = t->start;
+	*length = t->length;
+	*target_type = t->type;
+	*params = t->params;
+
+	return t->next;
+}
+
+/* Unmarshall the target info returned from a status call */
+static int _unmarshal_status(struct dm_task *dmt, struct dm_ioctl *dmi)
+{
+	char *outbuf = (char *) dmi + dmi->data_start;
+	char *outptr = outbuf;
+	uint32_t i;
+	struct dm_target_spec *spec;
+
+	for (i = 0; i < dmi->target_count; i++) {
+		spec = (struct dm_target_spec *) outptr;
+		if (!dm_task_add_target(dmt, spec->sector_start,
+					spec->length,
+					spec->target_type,
+					outptr + sizeof(*spec)))
+			return 0;
+
+		outptr = outbuf + spec->next;
+	}
+
+	return 1;
+}
+
+int dm_format_dev(char *buf, int bufsize, uint32_t dev_major,
+		  uint32_t dev_minor)
+{
+	int r;
+
+#ifdef DM_COMPAT
+	if (_dm_version == 1)
+		return _dm_format_dev_v1(buf, bufsize, dev_major, dev_minor);
+#endif
+
+	if (bufsize < 8)
+		return 0;
+
+	r = snprintf(buf, bufsize, "%03u:%03u", dev_major, dev_minor);
+	if (r < 0 || r > bufsize - 1)
+		return 0;
+
+	return 1;
+}
+
+int dm_task_get_info(struct dm_task *dmt, struct dm_info *info)
+{
+#ifdef DM_COMPAT
+	if (_dm_version == 1)
+		return _dm_task_get_info_v1(dmt, info);
+#endif
+
+	if (!dmt->dmi.v4)
+		return 0;
+
+	memset(info, 0, sizeof(*info));
+
+	info->exists = dmt->dmi.v4->flags & DM_EXISTS_FLAG ? 1 : 0;
+	if (!info->exists)
+		return 1;
+
+	info->suspended = dmt->dmi.v4->flags & DM_SUSPEND_FLAG ? 1 : 0;
+	info->read_only = dmt->dmi.v4->flags & DM_READONLY_FLAG ? 1 : 0;
+	info->live_table = dmt->dmi.v4->flags & DM_ACTIVE_PRESENT_FLAG ? 1 : 0;
+	info->inactive_table = dmt->dmi.v4->flags & DM_INACTIVE_PRESENT_FLAG ?
+	    1 : 0;
+	info->target_count = dmt->dmi.v4->target_count;
+	info->open_count = dmt->dmi.v4->open_count;
+	info->event_nr = dmt->dmi.v4->event_nr;
+	info->major = MAJOR(dmt->dmi.v4->dev);
+	info->minor = MINOR(dmt->dmi.v4->dev);
+
+	return 1;
+}
+
+const char *dm_task_get_name(struct dm_task *dmt)
+{
+#ifdef DM_COMPAT
+	if (_dm_version == 1)
+		return _dm_task_get_name_v1(dmt);
+#endif
+
+	return (dmt->dmi.v4->name);
+}
+
+const char *dm_task_get_uuid(struct dm_task *dmt)
+{
+#ifdef DM_COMPAT
+	if (_dm_version == 1)
+		return _dm_task_get_uuid_v1(dmt);
+#endif
+
+	return (dmt->dmi.v4->uuid);
+}
+
+struct dm_deps *dm_task_get_deps(struct dm_task *dmt)
+{
+#ifdef DM_COMPAT
+	if (_dm_version == 1)
+		return _dm_task_get_deps_v1(dmt);
+#endif
+
+	return (struct dm_deps *) (((void *) dmt->dmi.v4) +
+				   dmt->dmi.v4->data_start);
+}
+
+struct dm_names *dm_task_get_names(struct dm_task *dmt)
+{
+#ifdef DM_COMPAT
+	if (_dm_version == 1)
+		return _dm_task_get_names_v1(dmt);
+#endif
+
+	return (struct dm_names *) (((void *) dmt->dmi.v4) +
+				    dmt->dmi.v4->data_start);
+}
+
+int dm_task_set_ro(struct dm_task *dmt)
+{
+	dmt->read_only = 1;
+	return 1;
+}
+
+int dm_task_set_newname(struct dm_task *dmt, const char *newname)
+{
+	if (!(dmt->newname = strdup(newname))) {
+		log_error("dm_task_set_newname: strdup(%s) failed", newname);
+		return 0;
+	}
+
+	return 1;
+}
+
+int dm_task_set_event_nr(struct dm_task *dmt, uint32_t event_nr)
+{
+	dmt->event_nr = event_nr;
+
+	return 1;
+}
+
+struct target *create_target(uint64_t start, uint64_t len, const char *type,
+			     const char *params)
+{
+	struct target *t = malloc(sizeof(*t));
+
+	if (!t) {
+		log_error("create_target: malloc(%d) failed", sizeof(*t));
+		return NULL;
+	}
+
+	memset(t, 0, sizeof(*t));
+
+	if (!(t->params = strdup(params))) {
+		log_error("create_target: strdup(params) failed");
+		goto bad;
+	}
+
+	if (!(t->type = strdup(type))) {
+		log_error("create_target: strdup(type) failed");
+		goto bad;
+	}
+
+	t->start = start;
+	t->length = len;
+	return t;
+
+      bad:
+	free(t->params);
+	free(t->type);
+	free(t);
+	return NULL;
+}
+
+static void *_add_target(struct target *t, void *out, void *end)
+{
+	void *out_sp = out;
+	struct dm_target_spec sp;
+	size_t sp_size = sizeof(struct dm_target_spec);
+	int len;
+	const char no_space[] = "Ran out of memory building ioctl parameter";
+
+	out += sp_size;
+	if (out >= end) {
+		log_error(no_space);
+		return NULL;
+	}
+
+	sp.status = 0;
+	sp.sector_start = t->start;
+	sp.length = t->length;
+	strncpy(sp.target_type, t->type, sizeof(sp.target_type));
+
+	len = strlen(t->params);
+
+	if ((out + len + 1) >= end) {
+		log_error(no_space);
+
+		log_error("t->params= '%s'", t->params);
+		return NULL;
+	}
+	strcpy((char *) out, t->params);
+	out += len + 1;
+
+	/* align next block */
+	out = _align(out, ALIGNMENT);
+
+	sp.next = out - out_sp;
+	memcpy(out_sp, &sp, sp_size);
+
+	return out;
+}
+
+static struct dm_ioctl *_flatten(struct dm_task *dmt)
+{
+	const size_t min_size = 16 * 1024;
+	const int (*version)[3];
+
+	struct dm_ioctl *dmi;
+	struct target *t;
+	size_t len = sizeof(struct dm_ioctl);
+	void *b, *e;
+	int count = 0;
+
+	for (t = dmt->head; t; t = t->next) {
+		len += sizeof(struct dm_target_spec);
+		len += strlen(t->params) + 1 + ALIGNMENT;
+		count++;
+	}
+
+	if (count && dmt->newname) {
+		log_error("targets and newname are incompatible");
+		return NULL;
+	}
+
+	if (dmt->newname)
+		len += strlen(dmt->newname) + 1;
+
+	/*
+	 * Give len a minimum size so that we have space to store
+	 * dependencies or status information.
+	 */
+	if (len < min_size)
+		len = min_size;
+
+	if (!(dmi = malloc(len)))
+		return NULL;
+
+	memset(dmi, 0, len);
+
+	version = &_cmd_data_v4[dmt->type].version;
+
+	dmi->version[0] = (*version)[0];
+	dmi->version[1] = (*version)[1];
+	dmi->version[2] = (*version)[2];
+
+	dmi->data_size = len;
+	dmi->data_start = sizeof(struct dm_ioctl);
+
+	if (dmt->dev_name)
+		strncpy(dmi->name, dmt->dev_name, sizeof(dmi->name));
+
+	if (dmt->type == DM_DEVICE_SUSPEND)
+		dmi->flags |= DM_SUSPEND_FLAG;
+	if (dmt->read_only)
+		dmi->flags |= DM_READONLY_FLAG;
+
+	if (dmt->minor >= 0) {
+		if (dmt->major <= 0) {
+			log_error("Missing major number for persistent device");
+			return NULL;
+		}
+		dmi->flags |= DM_PERSISTENT_DEV_FLAG;
+		dmi->dev = MKDEV(dmt->major, dmt->minor);
+	}
+
+	if (dmt->uuid)
+		strncpy(dmi->uuid, dmt->uuid, sizeof(dmi->uuid));
+
+	dmi->target_count = count;
+	dmi->event_nr = dmt->event_nr;
+
+	b = (void *) (dmi + 1);
+	e = (void *) ((char *) dmi + len);
+
+	for (t = dmt->head; t; t = t->next)
+		if (!(b = _add_target(t, b, e)))
+			goto bad;
+
+	if (dmt->newname)
+		strcpy(b, dmt->newname);
+
+	return dmi;
+
+      bad:
+	free(dmi);
+	return NULL;
+}
+
+static int _create_and_load_v4(struct dm_task *dmt)
+{
+	struct dm_task *task;
+	int r;
+
+	/* Use new task struct to create the device */
+	if (!(task = dm_task_create(DM_DEVICE_CREATE))) {
+		log_error("Failed to create device-mapper task struct");
+		return 0;
+	}
+
+	/* Copy across relevant fields */
+	if (dmt->dev_name && !dm_task_set_name(task, dmt->dev_name)) {
+		dm_task_destroy(task);
+		return 0;
+	}
+
+	if (dmt->uuid && !dm_task_set_uuid(task, dmt->uuid)) {
+		dm_task_destroy(task);
+		return 0;
+	}
+
+	task->major = dmt->major;
+	task->minor = dmt->minor;
+
+	r = dm_task_run(task);
+	dm_task_destroy(task);
+	if (!r)
+		return r;
+
+	/* Next load the table */
+	if (!(task = dm_task_create(DM_DEVICE_RELOAD))) {
+		log_error("Failed to create device-mapper task struct");
+		return 0;
+	}
+
+	/* Copy across relevant fields */
+	if (dmt->dev_name && !dm_task_set_name(task, dmt->dev_name)) {
+		dm_task_destroy(task);
+		return 0;
+	}
+
+	task->read_only = dmt->read_only;
+	task->head = dmt->head;
+	task->tail = dmt->tail;
+
+	r = dm_task_run(task);
+
+	task->head = NULL;
+	task->tail = NULL;
+	dm_task_destroy(task);
+	if (!r)
+		return r;
+
+	/* Use the original structure last so the info will be correct */
+	dmt->type = DM_DEVICE_RESUME;
+	dmt->uuid = NULL;
+	free(dmt->uuid);
+
+	r = dm_task_run(dmt);
+
+	return r;
+}
+
+int dm_task_run(struct dm_task *dmt)
+{
+	struct dm_ioctl *dmi = NULL;
+	unsigned int command;
+
+#ifdef DM_COMPAT
+	if (_dm_version == 1)
+		return _dm_task_run_v1(dmt);
+#endif
+
+	if ((unsigned) dmt->type >=
+	    (sizeof(_cmd_data_v4) / sizeof(*_cmd_data_v4))) {
+		log_error("Internal error: unknown device-mapper task %d",
+			  dmt->type);
+		goto bad;
+	}
+
+	command = _cmd_data_v4[dmt->type].cmd;
+
+	/* Old-style creation had a table supplied */
+	if (dmt->type == DM_DEVICE_CREATE && dmt->head)
+		return _create_and_load_v4(dmt);
+
+	if (!_open_control())
+		return 0;
+
+	dmi = _flatten(dmt);
+	if (!dmi) {
+		log_error("Couldn't create ioctl argument");
+		return 0;
+	}
+
+	if (dmt->type == DM_DEVICE_TABLE)
+		dmi->flags |= DM_STATUS_TABLE_FLAG;
+
+	dmi->flags |= DM_EXISTS_FLAG;	/* FIXME */
+	log_debug("dm %s %s %s %s", _cmd_data_v4[dmt->type].name, dmi->name,
+		  dmi->uuid, dmt->newname ? dmt->newname : "");
+	if (ioctl(_control_fd, command, dmi) < 0) {
+		if (errno == ENXIO && ((dmt->type == DM_DEVICE_INFO) ||
+				       (dmt->type == DM_DEVICE_MKNODES))) {
+			dmi->flags &= ~DM_EXISTS_FLAG;	/* FIXME */
+			goto ignore_error;
+		}
+		if (_log_suppress)
+			log_verbose("device-mapper ioctl cmd %d failed: %s",
+				    _IOC_NR(command), strerror(errno));
+		else
+			log_error("device-mapper ioctl cmd %d failed: %s",
+				  _IOC_NR(command), strerror(errno));
+		goto bad;
+	}
+
+      ignore_error:
+	switch (dmt->type) {
+	case DM_DEVICE_CREATE:
+		add_dev_node(dmt->dev_name, MAJOR(dmi->dev), MINOR(dmi->dev));
+		break;
+
+	case DM_DEVICE_REMOVE:
+		rm_dev_node(dmt->dev_name);
+		break;
+
+	case DM_DEVICE_RENAME:
+		rename_dev_node(dmt->dev_name, dmt->newname);
+		break;
+
+	case DM_DEVICE_MKNODES:
+		if (dmi->flags & DM_EXISTS_FLAG)
+			add_dev_node(dmt->dev_name, MAJOR(dmi->dev),
+				     MINOR(dmi->dev));
+		else
+			rm_dev_node(dmt->dev_name);
+		break;
+
+	case DM_DEVICE_STATUS:
+	case DM_DEVICE_TABLE:
+	case DM_DEVICE_WAITEVENT:
+		if (!_unmarshal_status(dmt, dmi))
+			goto bad;
+		break;
+	}
+
+	dmt->dmi.v4 = dmi;
+	return 1;
+
+      bad:
+	free(dmi);
+	return 0;
+}
+
+void dm_lib_release(void)
+{
+	if (_control_fd != -1) {
+		close(_control_fd);
+		_control_fd = -1;
+	}
+	update_devs();
+}
+
+void dm_lib_exit(void)
+{
+	if (_control_fd != -1) {
+		close(_control_fd);
+		_control_fd = -1;
+	}
+	_version_ok = 1;
+	_version_checked = 0;
+}
diff --git a/extras/multipath/libdevmapper/ioctl/libdm-compat.h b/extras/multipath/libdevmapper/ioctl/libdm-compat.h
new file mode 100644
index 0000000000..af7a9f1f71
--- /dev/null
+++ b/extras/multipath/libdevmapper/ioctl/libdm-compat.h
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef _LINUX_LIBDM_COMPAT_H
+#define _LINUX_LIBDM_COMPAT_H
+
+#include <inttypes.h>
+#include <linux/dm-ioctl.h>
+#include <linux/kdev_t.h>
+#include <sys/ioctl.h>
+
+struct dm_task;
+struct dm_info;
+
+/*
+ * Old versions of structures for backwards compatibility.
+ */
+
+struct dm_ioctl_v1 {
+	uint32_t version[3];	/* in/out */
+	uint32_t data_size;	/* total size of data passed in
+				 * including this struct */
+
+	uint32_t data_start;	/* offset to start of data
+				 * relative to start of this struct */
+
+	int32_t target_count;	/* in/out */
+	int32_t open_count;	/* out */
+	uint32_t flags;		/* in/out */
+
+	__kernel_dev_t dev;	/* in/out */
+
+	char name[DM_NAME_LEN];	/* device name */
+	char uuid[DM_UUID_LEN];	/* unique identifier for
+				 * the block device */
+};
+
+struct dm_target_spec_v1 {
+	int32_t status;		/* used when reading from kernel only */
+	uint64_t sector_start;
+	uint32_t length;
+	uint32_t next;
+
+	char target_type[DM_MAX_TYPE_NAME];
+
+};
+
+struct dm_target_deps_v1 {
+	uint32_t count;
+
+	__kernel_dev_t dev[0];	/* out */
+};
+
+enum {
+	/* Top level cmds */
+	DM_VERSION_CMD_V1 = 0,
+	DM_REMOVE_ALL_CMD_V1,
+
+	/* device level cmds */
+	DM_DEV_CREATE_CMD_V1,
+	DM_DEV_REMOVE_CMD_V1,
+	DM_DEV_RELOAD_CMD_V1,
+	DM_DEV_RENAME_CMD_V1,
+	DM_DEV_SUSPEND_CMD_V1,
+	DM_DEV_DEPS_CMD_V1,
+	DM_DEV_STATUS_CMD_V1,
+
+	/* target level cmds */
+	DM_TARGET_STATUS_CMD_V1,
+	DM_TARGET_WAIT_CMD_V1,
+};
+
+#define DM_VERSION_V1       _IOWR(DM_IOCTL, DM_VERSION_CMD_V1, struct dm_ioctl)
+#define DM_REMOVE_ALL_V1    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD_V1, struct dm_ioctl)
+
+#define DM_DEV_CREATE_V1    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD_V1, struct dm_ioctl)
+#define DM_DEV_REMOVE_V1    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD_V1, struct dm_ioctl)
+#define DM_DEV_RELOAD_V1    _IOWR(DM_IOCTL, DM_DEV_RELOAD_CMD_V1, struct dm_ioctl)
+#define DM_DEV_SUSPEND_V1   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD_V1, struct dm_ioctl)
+#define DM_DEV_RENAME_V1    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD_V1, struct dm_ioctl)
+#define DM_DEV_DEPS_V1      _IOWR(DM_IOCTL, DM_DEV_DEPS_CMD_V1, struct dm_ioctl)
+#define DM_DEV_STATUS_V1    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD_V1, struct dm_ioctl)
+
+#define DM_TARGET_STATUS_V1 _IOWR(DM_IOCTL, DM_TARGET_STATUS_CMD_V1, struct dm_ioctl)
+#define DM_TARGET_WAIT_V1   _IOWR(DM_IOCTL, DM_TARGET_WAIT_CMD_V1, struct dm_ioctl)
+
+/* *INDENT-OFF* */
+static struct cmd_data _cmd_data_v1[] = {
+        { "create",	DM_DEV_CREATE_V1,	{1, 0, 0} },
+        { "reload",	DM_DEV_RELOAD_V1,	{1, 0, 0} },
+        { "remove",	DM_DEV_REMOVE_V1,	{1, 0, 0} },
+        { "remove_all",	DM_REMOVE_ALL_V1,	{1, 0, 0} },
+        { "suspend",	DM_DEV_SUSPEND_V1,	{1, 0, 0} },
+        { "resume",	DM_DEV_SUSPEND_V1,	{1, 0, 0} },
+        { "info",	DM_DEV_STATUS_V1,	{1, 0, 0} },
+        { "deps",	DM_DEV_DEPS_V1,		{1, 0, 0} },
+        { "rename",	DM_DEV_RENAME_V1,	{1, 0, 0} },
+        { "version",	DM_VERSION_V1,		{1, 0, 0} },
+        { "status",	DM_TARGET_STATUS_V1,	{1, 0, 0} },
+        { "table",	DM_TARGET_STATUS_V1,	{1, 0, 0} },
+        { "waitevent",	DM_TARGET_WAIT_V1,	{1, 0, 0} },
+        { "names",	0,			{4, 0, 0} },
+        { "clear",	0,			{4, 0, 0} },
+        { "mknodes",	0,			{4, 0, 0} },
+};
+/* *INDENT-ON* */
+
+#endif
diff --git a/extras/multipath/libdevmapper/ioctl/libdm-targets.h b/extras/multipath/libdevmapper/ioctl/libdm-targets.h
new file mode 100644
index 0000000000..a8c0e20547
--- /dev/null
+++ b/extras/multipath/libdevmapper/ioctl/libdm-targets.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef LIB_DMTARGETS_H
+#define LIB_DMTARGETS_H
+
+#include <inttypes.h>
+
+struct dm_ioctl;
+struct dm_ioctl_v1;
+
+struct target {
+	uint64_t start;
+	uint64_t length;
+	char *type;
+	char *params;
+
+	struct target *next;
+};
+
+struct dm_task {
+	int type;
+	char *dev_name;
+
+	struct target *head, *tail;
+
+	int read_only;
+	uint32_t event_nr;
+	int major;
+	int minor;
+	union {
+		struct dm_ioctl *v4;
+		struct dm_ioctl_v1 *v1;
+	} dmi;
+	char *newname;
+
+	char *uuid;
+};
+
+struct cmd_data {
+	const char *name;
+	const int cmd;
+	const int version[3];
+};
+
+int dm_check_version(void);
+
+#endif
diff --git a/extras/multipath/libdevmapper/libdevmapper.h b/extras/multipath/libdevmapper/libdevmapper.h
new file mode 100644
index 0000000000..6549af3641
--- /dev/null
+++ b/extras/multipath/libdevmapper/libdevmapper.h
@@ -0,0 +1,147 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef LIB_DEVICE_MAPPER_H
+#define LIB_DEVICE_MAPPER_H
+
+#include <inttypes.h>
+#include <sys/types.h>
+
+#ifdef linux
+#  include <linux/types.h>
+#endif
+
+/*
+ * Since it is quite laborious to build the ioctl
+ * arguments for the device-mapper people are
+ * encouraged to use this library.
+ *
+ * You will need to build a struct dm_task for
+ * each ioctl command you want to execute.
+ */
+
+typedef void (*dm_log_fn) (int level, const char *file, int line,
+			   const char *f, ...);
+
+/*
+ * The library user may wish to register their own
+ * logging function, by default errors go to
+ * stderr.
+ */
+void dm_log_init(dm_log_fn fn);
+void dm_log_init_verbose(int level);
+
+enum {
+	DM_DEVICE_CREATE,
+	DM_DEVICE_RELOAD,
+	DM_DEVICE_REMOVE,
+	DM_DEVICE_REMOVE_ALL,
+
+	DM_DEVICE_SUSPEND,
+	DM_DEVICE_RESUME,
+
+	DM_DEVICE_INFO,
+	DM_DEVICE_DEPS,
+	DM_DEVICE_RENAME,
+
+	DM_DEVICE_VERSION,
+
+	DM_DEVICE_STATUS,
+	DM_DEVICE_TABLE,
+	DM_DEVICE_WAITEVENT,
+
+	DM_DEVICE_LIST,
+
+	DM_DEVICE_CLEAR,
+
+	DM_DEVICE_MKNODES
+};
+
+struct dm_task;
+
+struct dm_task *dm_task_create(int type);
+void dm_task_destroy(struct dm_task *dmt);
+
+int dm_task_set_name(struct dm_task *dmt, const char *name);
+int dm_task_set_uuid(struct dm_task *dmt, const char *uuid);
+
+/*
+ * Retrieve attributes after an info.
+ */
+struct dm_info {
+	int exists;
+	int suspended;
+	int live_table;
+	int inactive_table;
+	int32_t open_count;
+	uint32_t event_nr;
+	uint32_t major;
+	uint32_t minor;		/* minor device number */
+	int read_only;		/* 0:read-write; 1:read-only */
+
+	int32_t target_count;
+};
+
+struct dm_deps {
+	uint32_t count;
+	uint32_t filler;
+	uint64_t device[0];
+};
+
+struct dm_names {
+	uint64_t dev;
+	uint32_t next;		/* Offset to next struct from start of this struct */
+	char name[0];
+};
+
+int dm_get_library_version(char *version, size_t size);
+int dm_task_get_driver_version(struct dm_task *dmt, char *version, size_t size);
+int dm_task_get_info(struct dm_task *dmt, struct dm_info *dmi);
+const char *dm_task_get_name(struct dm_task *dmt);
+const char *dm_task_get_uuid(struct dm_task *dmt);
+
+struct dm_deps *dm_task_get_deps(struct dm_task *dmt);
+struct dm_names *dm_task_get_names(struct dm_task *dmt);
+
+int dm_task_set_ro(struct dm_task *dmt);
+int dm_task_set_newname(struct dm_task *dmt, const char *newname);
+int dm_task_set_minor(struct dm_task *dmt, int minor);
+int dm_task_set_major(struct dm_task *dmt, int major);
+int dm_task_set_event_nr(struct dm_task *dmt, uint32_t event_nr);
+
+/*
+ * Use these to prepare for a create or reload.
+ */
+int dm_task_add_target(struct dm_task *dmt,
+		       uint64_t start,
+		       uint64_t size, const char *ttype, const char *params);
+
+/*
+ * Format major/minor numbers correctly for input to driver
+ */
+int dm_format_dev(char *buf, int bufsize, uint32_t dev_major, uint32_t dev_minor);
+
+/* Use this to retrive target information returned from a STATUS call */
+void *dm_get_next_target(struct dm_task *dmt,
+			 void *next, uint64_t *start, uint64_t *length,
+			 char **target_type, char **params);
+
+/*
+ * Call this to actually run the ioctl.
+ */
+int dm_task_run(struct dm_task *dmt);
+
+/*
+ * Configure the device-mapper directory
+ */
+int dm_set_dev_dir(const char *dir);
+const char *dm_dir(void);
+
+/* Release library resources */
+void dm_lib_release(void);
+void dm_lib_exit(void);
+
+#endif				/* LIB_DEVICE_MAPPER_H */
diff --git a/extras/multipath/libdevmapper/libdm-common.c b/extras/multipath/libdevmapper/libdm-common.c
new file mode 100644
index 0000000000..b0affd1eed
--- /dev/null
+++ b/extras/multipath/libdevmapper/libdm-common.c
@@ -0,0 +1,382 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#include "libdm-targets.h"
+#include "libdm-common.h"
+#include "list.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+#include <linux/dm-ioctl.h>
+#include <linux/kdev_t.h>
+
+#define DEV_DIR "/dev/"
+
+static char _dm_dir[PATH_MAX] = DEV_DIR DM_DIR;
+
+static int _verbose = 0;
+
+/*
+ * Library users can provide their own logging
+ * function.
+ */
+static void _default_log(int level, const char *file, int line,
+			 const char *f, ...)
+{
+	va_list ap;
+
+	if (level > _LOG_WARN && !_verbose)
+		return;
+
+	va_start(ap, f);
+
+	if (level < _LOG_WARN)
+		vfprintf(stderr, f, ap);
+	else
+		vprintf(f, ap);
+
+	va_end(ap);
+
+	if (level < _LOG_WARN)
+		fprintf(stderr, "\n");
+	else
+		fprintf(stdout, "\n");
+}
+
+dm_log_fn _log = _default_log;
+
+void dm_log_init(dm_log_fn fn)
+{
+	_log = fn;
+}
+
+void dm_log_init_verbose(int level)
+{
+	_verbose = level;
+}
+
+static void _build_dev_path(char *buffer, size_t len, const char *dev_name)
+{
+	/* If there's a /, assume caller knows what they're doing */
+	if (strchr(dev_name, '/'))
+		snprintf(buffer, len, "%s", dev_name);
+	else
+		snprintf(buffer, len, "%s/%s", _dm_dir, dev_name);
+}
+
+int dm_get_library_version(char *version, size_t size)
+{
+	strncpy(version, DM_LIB_VERSION, size);
+	return 1;
+}
+
+struct dm_task *dm_task_create(int type)
+{
+	struct dm_task *dmt = malloc(sizeof(*dmt));
+
+	if (!dm_check_version())
+		return NULL;
+
+	if (!dmt) {
+		log_error("dm_task_create: malloc(%d) failed", sizeof(*dmt));
+		return NULL;
+	}
+
+	memset(dmt, 0, sizeof(*dmt));
+
+	dmt->type = type;
+	dmt->minor = -1;
+	dmt->major = -1;
+
+	return dmt;
+}
+
+int dm_task_set_name(struct dm_task *dmt, const char *name)
+{
+	char *pos;
+	char path[PATH_MAX];
+	struct stat st1, st2;
+
+	if (dmt->dev_name) {
+		free(dmt->dev_name);
+		dmt->dev_name = NULL;
+	}
+
+	/* If path was supplied, remove it if it points to the same device
+	 * as its last component.
+	 */
+	if ((pos = strrchr(name, '/'))) {
+		snprintf(path, sizeof(path), "%s/%s", _dm_dir, pos + 1);
+
+		if (stat(name, &st1) || stat(path, &st2) ||
+		    !(st1.st_dev == st2.st_dev)) {
+			log_error("dm_task_set_name: Device %s not found",
+				  name);
+			return 0;
+		}
+
+		name = pos + 1;
+	}
+
+	if (!(dmt->dev_name = strdup(name))) {
+		log_error("dm_task_set_name: strdup(%s) failed", name);
+		return 0;
+	}
+
+	return 1;
+}
+
+int dm_task_set_uuid(struct dm_task *dmt, const char *uuid)
+{
+	if (dmt->uuid) {
+		free(dmt->uuid);
+		dmt->uuid = NULL;
+	}
+
+	if (!(dmt->uuid = strdup(uuid))) {
+		log_error("dm_task_set_uuid: strdup(%s) failed", uuid);
+		return 0;
+	}
+
+	return 1;
+}
+
+int dm_task_set_major(struct dm_task *dmt, int major)
+{
+	dmt->major = major;
+	log_debug("Setting major: %d", dmt->major);
+
+	return 1;
+}
+
+int dm_task_set_minor(struct dm_task *dmt, int minor)
+{
+	dmt->minor = minor;
+	log_debug("Setting minor: %d", dmt->minor);
+
+	return 1;
+}
+
+int dm_task_add_target(struct dm_task *dmt, uint64_t start, uint64_t size,
+		       const char *ttype, const char *params)
+{
+	struct target *t = create_target(start, size, ttype, params);
+
+	if (!t)
+		return 0;
+
+	if (!dmt->head)
+		dmt->head = dmt->tail = t;
+	else {
+		dmt->tail->next = t;
+		dmt->tail = t;
+	}
+
+	return 1;
+}
+
+static int _add_dev_node(const char *dev_name, uint32_t major, uint32_t minor)
+{
+	char path[PATH_MAX];
+	struct stat info;
+	dev_t dev = MKDEV(major, minor);
+
+	_build_dev_path(path, sizeof(path), dev_name);
+
+	if (stat(path, &info) >= 0) {
+		if (!S_ISBLK(info.st_mode)) {
+			log_error("A non-block device file at '%s' "
+				  "is already present", path);
+			return 0;
+		}
+
+		if (info.st_rdev == dev)
+			return 1;
+
+		if (unlink(path) < 0) {
+			log_error("Unable to unlink device node for '%s'",
+				  dev_name);
+			return 0;
+		}
+	}
+
+	if (mknod(path, S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP, dev) < 0) {
+		log_error("Unable to make device node for '%s'", dev_name);
+		return 0;
+	}
+
+	return 1;
+}
+
+static int _rename_dev_node(const char *old_name, const char *new_name)
+{
+	char oldpath[PATH_MAX];
+	char newpath[PATH_MAX];
+	struct stat info;
+
+	_build_dev_path(oldpath, sizeof(oldpath), old_name);
+	_build_dev_path(newpath, sizeof(newpath), new_name);
+
+	if (stat(newpath, &info) == 0) {
+		if (!S_ISBLK(info.st_mode)) {
+			log_error("A non-block device file at '%s' "
+				  "is already present", newpath);
+			return 0;
+		}
+
+		if (unlink(newpath) < 0) {
+			if (errno == EPERM) {
+				/* devfs, entry has already been renamed */
+				return 1;
+			}
+			log_error("Unable to unlink device node for '%s'",
+				  new_name);
+			return 0;
+		}
+	}
+
+	if (rename(oldpath, newpath) < 0) {
+		log_error("Unable to rename device node from '%s' to '%s'",
+			  old_name, new_name);
+		return 0;
+	}
+
+	return 1;
+}
+
+static int _rm_dev_node(const char *dev_name)
+{
+	char path[PATH_MAX];
+	struct stat info;
+
+	_build_dev_path(path, sizeof(path), dev_name);
+
+	if (stat(path, &info) < 0)
+		return 1;
+
+	if (unlink(path) < 0) {
+		log_error("Unable to unlink device node for '%s'", dev_name);
+		return 0;
+	}
+
+	return 1;
+}
+
+typedef enum {
+	NODE_ADD,
+	NODE_DEL,
+	NODE_RENAME
+} node_op_t;
+
+static int _do_node_op(node_op_t type, const char *dev_name, uint32_t major,
+		       uint32_t minor, const char *old_name)
+{
+	switch (type) {
+	case NODE_ADD:
+		return _add_dev_node(dev_name, major, minor);
+	case NODE_DEL:
+		return _rm_dev_node(dev_name);
+	case NODE_RENAME:
+		return _rename_dev_node(old_name, dev_name);
+	}
+
+	return 1;
+}
+
+static LIST_INIT(_node_ops);
+
+struct node_op_parms {
+	struct list list;
+	node_op_t type;
+	char *dev_name;
+	uint32_t major;
+	uint32_t minor;
+	char *old_name;
+	char names[0];
+};
+
+static void _store_str(char **pos, char **ptr, const char *str)
+{
+	strcpy(*pos, str);
+	*ptr = *pos;
+	*pos += strlen(*ptr) + 1;
+}
+
+static int _stack_node_op(node_op_t type, const char *dev_name, uint32_t major,
+			  uint32_t minor, const char *old_name)
+{
+	struct node_op_parms *nop;
+	size_t len = strlen(dev_name) + strlen(old_name) + 2;
+	char *pos;
+
+	if (!(nop = malloc(sizeof(*nop) + len))) {
+		log_error("Insufficient memory to stack mknod operation");
+		return 0;
+	}
+
+	pos = nop->names;
+	nop->type = type;
+	nop->major = major;
+	nop->minor = minor;
+
+	_store_str(&pos, &nop->dev_name, dev_name);
+	_store_str(&pos, &nop->old_name, old_name);
+
+	list_add(&_node_ops, &nop->list);
+
+	return 1;
+}
+
+static void _pop_node_ops(void)
+{
+	struct list *noph, *nopht;
+	struct node_op_parms *nop;
+
+	list_iterate_safe(noph, nopht, &_node_ops) {
+		nop = list_item(noph, struct node_op_parms);
+		_do_node_op(nop->type, nop->dev_name, nop->major, nop->minor,
+			    nop->old_name);
+		list_del(&nop->list);
+		free(nop);
+	}
+}
+
+int add_dev_node(const char *dev_name, uint32_t major, uint32_t minor)
+{
+	return _stack_node_op(NODE_ADD, dev_name, major, minor, "");
+}
+
+int rename_dev_node(const char *old_name, const char *new_name)
+{
+	return _stack_node_op(NODE_RENAME, new_name, 0, 0, old_name);
+}
+
+int rm_dev_node(const char *dev_name)
+{
+	return _stack_node_op(NODE_DEL, dev_name, 0, 0, "");
+}
+
+void update_devs(void)
+{
+	_pop_node_ops();
+}
+
+int dm_set_dev_dir(const char *dir)
+{
+	snprintf(_dm_dir, sizeof(_dm_dir), "%s%s", dir, DM_DIR);
+	return 1;
+}
+
+const char *dm_dir(void)
+{
+	return _dm_dir;
+}
diff --git a/extras/multipath/libdevmapper/libdm-common.h b/extras/multipath/libdevmapper/libdm-common.h
new file mode 100644
index 0000000000..2b71242861
--- /dev/null
+++ b/extras/multipath/libdevmapper/libdm-common.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef LIB_DMCOMMON_H
+#define LIB_DMCOMMON_H
+
+#include "libdevmapper.h"
+
+#define _LOG_DEBUG 7
+#define _LOG_INFO 6
+#define _LOG_NOTICE 5
+#define _LOG_WARN 4
+#define _LOG_ERR 3
+#define _LOG_FATAL 2
+
+extern dm_log_fn _log;
+
+#define log_error(msg, x...) _log(_LOG_ERR, __FILE__, __LINE__, msg, ## x)
+#define log_print(msg, x...) _log(_LOG_WARN, __FILE__, __LINE__, msg, ## x)
+#define log_verbose(msg, x...) _log(_LOG_NOTICE, __FILE__, __LINE__, msg, ## x)
+#define log_very_verbose(msg, x...) _log(_LOG_INFO, __FILE__, __LINE__, msg, ## x)
+#define log_debug(msg, x...) _log(_LOG_DEBUG, __FILE__, __LINE__, msg, ## x)
+
+struct target *create_target(uint64_t start,
+			     uint64_t len,
+			     const char *type, const char *params);
+
+int add_dev_node(const char *dev_name, uint32_t minor, uint32_t major);
+int rm_dev_node(const char *dev_name);
+int rename_dev_node(const char *old_name, const char *new_name);
+void update_devs(void);
+
+#define DM_LIB_VERSION "1.00.07-ioctl (2003-11-21)"
+
+#endif
diff --git a/extras/multipath/libdevmapper/list.h b/extras/multipath/libdevmapper/list.h
new file mode 100644
index 0000000000..df3d32aea8
--- /dev/null
+++ b/extras/multipath/libdevmapper/list.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2001 Sistina Software
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef _LVM_LIST_H
+#define _LVM_LIST_H
+
+#include <assert.h>
+
+struct list {
+	struct list *n, *p;
+};
+
+#define LIST_INIT(name)	struct list name = { &(name), &(name) }
+
+static inline void list_init(struct list *head)
+{
+	head->n = head->p = head;
+}
+
+static inline void list_add(struct list *head, struct list *elem)
+{
+	assert(head->n);
+
+	elem->n = head;
+	elem->p = head->p;
+
+	head->p->n = elem;
+	head->p = elem;
+}
+
+static inline void list_add_h(struct list *head, struct list *elem)
+{
+	assert(head->n);
+
+	elem->n = head->n;
+	elem->p = head;
+
+	head->n->p = elem;
+	head->n = elem;
+}
+
+static inline void list_del(struct list *elem)
+{
+	elem->n->p = elem->p;
+	elem->p->n = elem->n;
+}
+
+static inline int list_empty(struct list *head)
+{
+	return head->n == head;
+}
+
+static inline int list_end(struct list *head, struct list *elem)
+{
+	return elem->n == head;
+}
+
+static inline struct list *list_next(struct list *head, struct list *elem)
+{
+	return (list_end(head, elem) ? NULL : elem->n);
+}
+
+#define list_iterate(v, head) \
+	for (v = (head)->n; v != head; v = v->n)
+
+#define list_uniterate(v, head, start) \
+	for (v = (start)->p; v != head; v = v->p)
+
+#define list_iterate_safe(v, t, head) \
+	for (v = (head)->n, t = v->n; v != head; v = t, t = v->n)
+
+static inline unsigned int list_size(const struct list *head)
+{
+	unsigned int s = 0;
+	const struct list *v;
+
+	list_iterate(v, head)
+	    s++;
+
+	return s;
+}
+
+#define list_item(v, t) \
+    ((t *)((uintptr_t)(v) - (uintptr_t)&((t *) 0)->list))
+
+#define list_struct_base(v, t, h) \
+    ((t *)((uintptr_t)(v) - (uintptr_t)&((t *) 0)->h))
+
+/* Given a known element in a known structure, locate another */
+#define struct_field(v, t, e, f) \
+    (((t *)((uintptr_t)(v) - (uintptr_t)&((t *) 0)->e))->f)
+
+/* Given a known element in a known structure, locate the list head */
+#define list_head(v, t, e) struct_field(v, t, e, list)
+
+#endif