init/do_mounts_dm.c - kernel/msm-4.9 - Gitiles

 /* do_mounts_dm.c
  * Copyright (C) 2010 The Chromium OS Authors <chromium-os-dev@chromium.org>
  *                    All Rights Reserved.
  * Based on do_mounts_md.c
  *
  * This file is released under the GPL.
  */
 #include <linux/device-mapper.h>
 #include <linux/fs.h>
 #include <linux/string.h>

 #include "do_mounts.h"
 #include "../drivers/md/dm.h"

 #define DM_MAX_NAME 32
 #define DM_MAX_UUID 129
 #define DM_NO_UUID "none"

 #define DM_MSG_PREFIX "init"

 /* Separators used for parsing the dm= argument. */
 #define DM_FIELD_SEP ' '
 #define DM_LINE_SEP ','

 /*
  * When the device-mapper and any targets are compiled into the kernel
  * (not a module), one target may be created and used as the root device at
  * boot time with the parameters given with the boot line dm=...
  * The code for that is here.
  */

 struct dm_setup_target {
 	sector_t begin;
 	sector_t length;
 	char *type;
 	char *params;
 	/* simple singly linked list */
 	struct dm_setup_target *next;
 };

 static struct {
 	int minor;
 	int ro;
 	char name[DM_MAX_NAME];
 	char uuid[DM_MAX_UUID];
 	char *targets;
 	struct dm_setup_target *target;
 	int target_count;
 } dm_setup_args __initdata;

 static __initdata int dm_early_setup;

 static size_t __init get_dm_option(char *str, char **next, char sep)
 {
 	size_t len = 0;
 	char *endp = NULL;

 	if (!str)
 		return 0;

 	endp = strchr(str, sep);
 	if (!endp) {  /* act like strchrnul */
 		len = strlen(str);
 		endp = str + len;
 	} else {
 		len = endp - str;
 	}

 	if (endp == str)
 		return 0;

 	if (!next)
 		return len;

 	if (*endp == 0) {
 		/* Don't advance past the nul. */
 		*next = endp;
 	} else {
 		*next = endp + 1;
 	}
 	return len;
 }

 static int __init dm_setup_args_init(void)
 {
 	dm_setup_args.minor = 0;
 	dm_setup_args.ro = 0;
 	dm_setup_args.target = NULL;
 	dm_setup_args.target_count = 0;
 	return 0;
 }

 static int __init dm_setup_cleanup(void)
 {
 	struct dm_setup_target *target = dm_setup_args.target;
 	struct dm_setup_target *old_target = NULL;
 	while (target) {
 		kfree(target->type);
 		kfree(target->params);
 		old_target = target;
 		target = target->next;
 		kfree(old_target);
 		dm_setup_args.target_count--;
 	}
 	BUG_ON(dm_setup_args.target_count);
 	return 0;
 }

 static char * __init dm_setup_parse_device_args(char *str)
 {
 	char *next = NULL;
 	size_t len = 0;

 	/* Grab the logical name of the device to be exported to udev */
 	len = get_dm_option(str, &next, DM_FIELD_SEP);
 	if (!len) {
 		DMERR("failed to parse device name");
 		goto parse_fail;
 	}
 	len = min(len + 1, sizeof(dm_setup_args.name));
 	strlcpy(dm_setup_args.name, str, len);  /* includes nul */
 	str = skip_spaces(next);

 	/* Grab the UUID value or "none" */
 	len = get_dm_option(str, &next, DM_FIELD_SEP);
 	if (!len) {
 		DMERR("failed to parse device uuid");
 		goto parse_fail;
 	}
 	len = min(len + 1, sizeof(dm_setup_args.uuid));
 	strlcpy(dm_setup_args.uuid, str, len);
 	str = skip_spaces(next);

 	/* Determine if the table/device will be read only or read-write */
 	if (!strncmp("ro,", str, 3)) {
 		dm_setup_args.ro = 1;
 	} else if (!strncmp("rw,", str, 3)) {
 		dm_setup_args.ro = 0;
 	} else {
 		DMERR("failed to parse table mode");
 		goto parse_fail;
 	}
 	str = skip_spaces(str + 3);

 	return str;

 parse_fail:
 	return NULL;
 }

 static void __init dm_substitute_devices(char *str, size_t str_len)
 {
 	char *candidate = str;
 	char *candidate_end = str;
 	char old_char;
 	size_t len = 0;
 	dev_t dev;

 	if (str_len < 3)
 		return;

 	while (str && *str) {
 		candidate = strchr(str, '/');
 		if (!candidate)
 			break;

 		/* Avoid embedded slashes */
 		if (candidate != str && *(candidate - 1) != DM_FIELD_SEP) {
 			str = strchr(candidate, DM_FIELD_SEP);
 			continue;
 		}

 		len = get_dm_option(candidate, &candidate_end, DM_FIELD_SEP);
 		str = skip_spaces(candidate_end);
 		if (len < 3 || len > 37)  /* name_to_dev_t max; maj:mix min */
 			continue;

 		/* Temporarily terminate with a nul */
 		if (*candidate_end)
 			candidate_end--;
 		old_char = *candidate_end;
 		*candidate_end = '\0';

 		DMDEBUG("converting candidate device '%s' to dev_t", candidate);
 		/* Use the boot-time specific device naming */
 		dev = name_to_dev_t(candidate);
 		*candidate_end = old_char;

 		DMDEBUG(" -> %u", dev);
 		/* No suitable replacement found */
 		if (!dev)
 			continue;

 		/* Rewrite the /dev/path as a major:minor */
 		len = snprintf(candidate, len, "%u:%u", MAJOR(dev), MINOR(dev));
 		if (!len) {
 			DMERR("error substituting device major/minor.");
 			break;
 		}
 		candidate += len;
 		/* Pad out with spaces (fixing our nul) */
 		while (candidate < candidate_end)
 			*(candidate++) = DM_FIELD_SEP;
 	}
 }

 static int __init dm_setup_parse_targets(char *str)
 {
 	char *next = NULL;
 	size_t len = 0;
 	struct dm_setup_target **target = NULL;

 	/* Targets are defined as per the table format but with a
 	 * comma as a newline separator. */
 	target = &dm_setup_args.target;
 	while (str && *str) {
 		*target = kzalloc(sizeof(struct dm_setup_target), GFP_KERNEL);
 		if (!*target) {
 			DMERR("failed to allocate memory for target %d",
 			      dm_setup_args.target_count);
 			goto parse_fail;
 		}
 		dm_setup_args.target_count++;

 		(*target)->begin = simple_strtoull(str, &next, 10);
 		if (!next || *next != DM_FIELD_SEP) {
 			DMERR("failed to parse starting sector for target %d",
 			      dm_setup_args.target_count - 1);
 			goto parse_fail;
 		}
 		str = skip_spaces(next + 1);

 		(*target)->length = simple_strtoull(str, &next, 10);
 		if (!next || *next != DM_FIELD_SEP) {
 			DMERR("failed to parse length for target %d",
 			      dm_setup_args.target_count - 1);
 			goto parse_fail;
 		}
 		str = skip_spaces(next + 1);

 		len = get_dm_option(str, &next, DM_FIELD_SEP);
 		if (!len ||
 		    !((*target)->type = kstrndup(str, len, GFP_KERNEL))) {
 			DMERR("failed to parse type for target %d",
 			      dm_setup_args.target_count - 1);
 			goto parse_fail;
 		}
 		str = skip_spaces(next);

 		len = get_dm_option(str, &next, DM_LINE_SEP);
 		if (!len ||
 		    !((*target)->params = kstrndup(str, len, GFP_KERNEL))) {
 			DMERR("failed to parse params for target %d",
 			      dm_setup_args.target_count - 1);
 			goto parse_fail;
 		}
 		str = skip_spaces(next);

 		/* Before moving on, walk through the copied target and
 		 * attempt to replace all /dev/xxx with the major:minor number.
 		 * It may not be possible to resolve them traditionally at
 		 * boot-time. */
 		dm_substitute_devices((*target)->params, len);

 		target = &((*target)->next);
 	}
 	DMDEBUG("parsed %d targets", dm_setup_args.target_count);

 	return 0;

 parse_fail:
 	return 1;
 }

 /*
  * Parse the command-line parameters given our kernel, but do not
  * actually try to invoke the DM device now; that is handled by
  * dm_setup_drive after the low-level disk drivers have initialised.
  * dm format is as follows:
  *  dm="name uuid fmode,[table line 1],[table line 2],..."
  * May be used with root=/dev/dm-0 as it always uses the first dm minor.
  */

 static int __init dm_setup(char *str)
 {
 	dm_setup_args_init();

 	str = dm_setup_parse_device_args(str);
 	if (!str) {
 		DMDEBUG("str is NULL");
 		goto parse_fail;
 	}

 	/* Target parsing is delayed until we have dynamic memory */
 	dm_setup_args.targets = str;

 	printk(KERN_INFO "dm: will configure '%s' on dm-%d\n",
 	       dm_setup_args.name, dm_setup_args.minor);

 	dm_early_setup = 1;
 	return 1;

 parse_fail:
 	printk(KERN_WARNING "dm: Invalid arguments supplied to dm=.\n");
 	return 0;
 }


 static void __init dm_setup_drive(void)
 {
 	struct mapped_device *md = NULL;
 	struct dm_table *table = NULL;
 	struct dm_setup_target *target;
 	char *uuid = dm_setup_args.uuid;
 	fmode_t fmode = FMODE_READ;

 	/* Finish parsing the targets. */
 	if (dm_setup_parse_targets(dm_setup_args.targets))
 		goto parse_fail;

 	if (dm_create(dm_setup_args.minor, &md)) {
 		DMDEBUG("failed to create the device");
 		goto dm_create_fail;
 	}
 	DMDEBUG("created device '%s'", dm_device_name(md));

 	/* In addition to flagging the table below, the disk must be
 	 * set explicitly ro/rw. */
 	set_disk_ro(dm_disk(md), dm_setup_args.ro);

 	if (!dm_setup_args.ro)
 		fmode |= FMODE_WRITE;
 	if (dm_table_create(&table, fmode, dm_setup_args.target_count, md)) {
 		DMDEBUG("failed to create the table");
 		goto dm_table_create_fail;
 	}

 	dm_lock_md_type(md);
 	target = dm_setup_args.target;
 	while (target) {
 		DMINFO("adding target '%llu %llu %s %s'",
 		       (unsigned long long) target->begin,
 		       (unsigned long long) target->length, target->type,
 		       target->params);
 		if (dm_table_add_target(table, target->type, target->begin,
 					target->length, target->params)) {
 			DMDEBUG("failed to add the target to the table");
 			goto add_target_fail;
 		}
 		target = target->next;
 	}

 	if (dm_table_complete(table)) {
 		DMDEBUG("failed to complete the table");
 		goto table_complete_fail;
 	}

 	if (dm_get_md_type(md) == DM_TYPE_NONE) {
 		dm_set_md_type(md, dm_table_get_type(table));
 		if (dm_setup_md_queue(md, table)) {
 			DMWARN("unable to set up device queue for new table.");
 			goto setup_md_queue_fail;
 		}
 	} else if (dm_get_md_type(md) != dm_table_get_type(table)) {
 		DMWARN("can't change device type after initial table load.");
 		goto setup_md_queue_fail;
         }

 	/* Suspend the device so that we can bind it to the table. */
 	if (dm_suspend(md, 0)) {
 		DMDEBUG("failed to suspend the device pre-bind");
 		goto suspend_fail;
 	}

 	/* Bind the table to the device. This is the only way to associate
 	 * md->map with the table and set the disk capacity directly. */
 	if (dm_swap_table(md, table)) {  /* should return NULL. */
 		DMDEBUG("failed to bind the device to the table");
 		goto table_bind_fail;
 	}

 	/* Finally, resume and the device should be ready. */
 	if (dm_resume(md)) {
 		DMDEBUG("failed to resume the device");
 		goto resume_fail;
 	}

 	/* Export the dm device via the ioctl interface */
 	if (!strcmp(DM_NO_UUID, dm_setup_args.uuid))
 		uuid = NULL;
 	if (dm_ioctl_export(md, dm_setup_args.name, uuid)) {
 		DMDEBUG("failed to export device with given name and uuid");
 		goto export_fail;
 	}
 	printk(KERN_INFO "dm: dm-%d is ready\n", dm_setup_args.minor);

 	dm_unlock_md_type(md);
 	dm_setup_cleanup();
 	return;

 export_fail:
 resume_fail:
 table_bind_fail:
 suspend_fail:
 setup_md_queue_fail:
 table_complete_fail:
 add_target_fail:
 	dm_unlock_md_type(md);
 dm_table_create_fail:
 	dm_put(md);
 dm_create_fail:
 	dm_setup_cleanup();
 parse_fail:
 	printk(KERN_WARNING "dm: starting dm-%d (%s) failed\n",
 	       dm_setup_args.minor, dm_setup_args.name);
 }

 __setup("dm=", dm_setup);

 void __init dm_run_setup(void)
 {
 	if (!dm_early_setup)
 		return;
 	printk(KERN_INFO "dm: attempting early device configuration.\n");
 	dm_setup_drive();
 }
	/* do_mounts_dm.c
	* Copyright (C) 2010 The Chromium OS Authors <chromium-os-dev@chromium.org>
	* All Rights Reserved.
	* Based on do_mounts_md.c
	*
	* This file is released under the GPL.
	*/
	#include <linux/device-mapper.h>
	#include <linux/fs.h>
	#include <linux/string.h>

	#include "do_mounts.h"
	#include "../drivers/md/dm.h"

	#define DM_MAX_NAME 32
	#define DM_MAX_UUID 129
	#define DM_NO_UUID "none"

	#define DM_MSG_PREFIX "init"

	/* Separators used for parsing the dm= argument. */
	#define DM_FIELD_SEP ' '
	#define DM_LINE_SEP ','

	/*
	* When the device-mapper and any targets are compiled into the kernel
	* (not a module), one target may be created and used as the root device at
	* boot time with the parameters given with the boot line dm=...
	* The code for that is here.
	*/

	struct dm_setup_target {
	sector_t begin;
	sector_t length;
	char *type;
	char *params;
	/* simple singly linked list */
	struct dm_setup_target *next;
	};

	static struct {
	int minor;
	int ro;
	char name[DM_MAX_NAME];
	char uuid[DM_MAX_UUID];
	char *targets;
	struct dm_setup_target *target;
	int target_count;
	} dm_setup_args __initdata;

	static __initdata int dm_early_setup;

	static size_t __init get_dm_option(char str, char *next, char sep)
	{
	size_t len = 0;
	char *endp = NULL;

	if (!str)
	return 0;

	endp = strchr(str, sep);
	if (!endp) { /* act like strchrnul */
	len = strlen(str);
	endp = str + len;
	} else {
	len = endp - str;
	}

	if (endp == str)
	return 0;

	if (!next)
	return len;

	if (*endp == 0) {
	/* Don't advance past the nul. */
	*next = endp;
	} else {
	*next = endp + 1;
	}
	return len;
	}

	static int __init dm_setup_args_init(void)
	{
	dm_setup_args.minor = 0;
	dm_setup_args.ro = 0;
	dm_setup_args.target = NULL;
	dm_setup_args.target_count = 0;
	return 0;
	}

	static int __init dm_setup_cleanup(void)
	{
	struct dm_setup_target *target = dm_setup_args.target;
	struct dm_setup_target *old_target = NULL;
	while (target) {
	kfree(target->type);
	kfree(target->params);
	old_target = target;
	target = target->next;
	kfree(old_target);
	dm_setup_args.target_count--;
	}
	BUG_ON(dm_setup_args.target_count);
	return 0;
	}

	static char * __init dm_setup_parse_device_args(char *str)
	{
	char *next = NULL;
	size_t len = 0;

	/* Grab the logical name of the device to be exported to udev */
	len = get_dm_option(str, &next, DM_FIELD_SEP);
	if (!len) {
	DMERR("failed to parse device name");
	goto parse_fail;
	}
	len = min(len + 1, sizeof(dm_setup_args.name));
	strlcpy(dm_setup_args.name, str, len); /* includes nul */
	str = skip_spaces(next);

	/* Grab the UUID value or "none" */
	len = get_dm_option(str, &next, DM_FIELD_SEP);
	if (!len) {
	DMERR("failed to parse device uuid");
	goto parse_fail;
	}
	len = min(len + 1, sizeof(dm_setup_args.uuid));
	strlcpy(dm_setup_args.uuid, str, len);
	str = skip_spaces(next);

	/* Determine if the table/device will be read only or read-write */
	if (!strncmp("ro,", str, 3)) {
	dm_setup_args.ro = 1;
	} else if (!strncmp("rw,", str, 3)) {
	dm_setup_args.ro = 0;
	} else {
	DMERR("failed to parse table mode");
	goto parse_fail;
	}
	str = skip_spaces(str + 3);

	return str;

	parse_fail:
	return NULL;
	}

	static void __init dm_substitute_devices(char *str, size_t str_len)
	{
	char *candidate = str;
	char *candidate_end = str;
	char old_char;
	size_t len = 0;
	dev_t dev;

	if (str_len < 3)
	return;

	while (str && *str) {
	candidate = strchr(str, '/');
	if (!candidate)
	break;

	/* Avoid embedded slashes */
	if (candidate != str && *(candidate - 1) != DM_FIELD_SEP) {
	str = strchr(candidate, DM_FIELD_SEP);
	continue;
	}

	len = get_dm_option(candidate, &candidate_end, DM_FIELD_SEP);
	str = skip_spaces(candidate_end);
	if (len < 3 \|\| len > 37) /* name_to_dev_t max; maj:mix min */
	continue;

	/* Temporarily terminate with a nul */
	if (*candidate_end)
	candidate_end--;
	old_char = *candidate_end;
	*candidate_end = '\0';

	DMDEBUG("converting candidate device '%s' to dev_t", candidate);
	/* Use the boot-time specific device naming */
	dev = name_to_dev_t(candidate);
	*candidate_end = old_char;

	DMDEBUG(" -> %u", dev);
	/* No suitable replacement found */
	if (!dev)
	continue;

	/* Rewrite the /dev/path as a major:minor */
	len = snprintf(candidate, len, "%u:%u", MAJOR(dev), MINOR(dev));
	if (!len) {
	DMERR("error substituting device major/minor.");
	break;
	}
	candidate += len;
	/* Pad out with spaces (fixing our nul) */
	while (candidate < candidate_end)
	*(candidate++) = DM_FIELD_SEP;
	}
	}

	static int __init dm_setup_parse_targets(char *str)
	{
	char *next = NULL;
	size_t len = 0;
	struct dm_setup_target **target = NULL;

	/* Targets are defined as per the table format but with a
	* comma as a newline separator. */
	target = &dm_setup_args.target;
	while (str && *str) {
	*target = kzalloc(sizeof(struct dm_setup_target), GFP_KERNEL);
	if (!*target) {
	DMERR("failed to allocate memory for target %d",
	dm_setup_args.target_count);
	goto parse_fail;
	}
	dm_setup_args.target_count++;

	(*target)->begin = simple_strtoull(str, &next, 10);
	if (!next \|\| *next != DM_FIELD_SEP) {
	DMERR("failed to parse starting sector for target %d",
	dm_setup_args.target_count - 1);
	goto parse_fail;
	}
	str = skip_spaces(next + 1);

	(*target)->length = simple_strtoull(str, &next, 10);
	if (!next \|\| *next != DM_FIELD_SEP) {
	DMERR("failed to parse length for target %d",
	dm_setup_args.target_count - 1);
	goto parse_fail;
	}
	str = skip_spaces(next + 1);

	len = get_dm_option(str, &next, DM_FIELD_SEP);
	if (!len \|\|
	!((*target)->type = kstrndup(str, len, GFP_KERNEL))) {
	DMERR("failed to parse type for target %d",
	dm_setup_args.target_count - 1);
	goto parse_fail;
	}
	str = skip_spaces(next);

	len = get_dm_option(str, &next, DM_LINE_SEP);
	if (!len \|\|
	!((*target)->params = kstrndup(str, len, GFP_KERNEL))) {
	DMERR("failed to parse params for target %d",
	dm_setup_args.target_count - 1);
	goto parse_fail;
	}
	str = skip_spaces(next);

	/* Before moving on, walk through the copied target and
	* attempt to replace all /dev/xxx with the major:minor number.
	* It may not be possible to resolve them traditionally at
	* boot-time. */
	dm_substitute_devices((*target)->params, len);

	target = &((*target)->next);
	}
	DMDEBUG("parsed %d targets", dm_setup_args.target_count);

	return 0;

	parse_fail:
	return 1;
	}

	/*
	* Parse the command-line parameters given our kernel, but do not
	* actually try to invoke the DM device now; that is handled by
	* dm_setup_drive after the low-level disk drivers have initialised.
	* dm format is as follows:
	* dm="name uuid fmode,[table line 1],[table line 2],..."
	* May be used with root=/dev/dm-0 as it always uses the first dm minor.
	*/

	static int __init dm_setup(char *str)
	{
	dm_setup_args_init();

	str = dm_setup_parse_device_args(str);
	if (!str) {
	DMDEBUG("str is NULL");
	goto parse_fail;
	}

	/* Target parsing is delayed until we have dynamic memory */
	dm_setup_args.targets = str;

	printk(KERN_INFO "dm: will configure '%s' on dm-%d\n",
	dm_setup_args.name, dm_setup_args.minor);

	dm_early_setup = 1;
	return 1;

	parse_fail:
	printk(KERN_WARNING "dm: Invalid arguments supplied to dm=.\n");
	return 0;
	}


	static void __init dm_setup_drive(void)
	{
	struct mapped_device *md = NULL;
	struct dm_table *table = NULL;
	struct dm_setup_target *target;
	char *uuid = dm_setup_args.uuid;
	fmode_t fmode = FMODE_READ;

	/* Finish parsing the targets. */
	if (dm_setup_parse_targets(dm_setup_args.targets))
	goto parse_fail;

	if (dm_create(dm_setup_args.minor, &md)) {
	DMDEBUG("failed to create the device");
	goto dm_create_fail;
	}
	DMDEBUG("created device '%s'", dm_device_name(md));

	/* In addition to flagging the table below, the disk must be
	* set explicitly ro/rw. */
	set_disk_ro(dm_disk(md), dm_setup_args.ro);

	if (!dm_setup_args.ro)
	fmode \|= FMODE_WRITE;
	if (dm_table_create(&table, fmode, dm_setup_args.target_count, md)) {
	DMDEBUG("failed to create the table");
	goto dm_table_create_fail;
	}

	dm_lock_md_type(md);
	target = dm_setup_args.target;
	while (target) {
	DMINFO("adding target '%llu %llu %s %s'",
	(unsigned long long) target->begin,
	(unsigned long long) target->length, target->type,
	target->params);
	if (dm_table_add_target(table, target->type, target->begin,
	target->length, target->params)) {
	DMDEBUG("failed to add the target to the table");
	goto add_target_fail;
	}
	target = target->next;
	}

	if (dm_table_complete(table)) {
	DMDEBUG("failed to complete the table");
	goto table_complete_fail;
	}

	if (dm_get_md_type(md) == DM_TYPE_NONE) {
	dm_set_md_type(md, dm_table_get_type(table));
	if (dm_setup_md_queue(md, table)) {
	DMWARN("unable to set up device queue for new table.");
	goto setup_md_queue_fail;
	}
	} else if (dm_get_md_type(md) != dm_table_get_type(table)) {
	DMWARN("can't change device type after initial table load.");
	goto setup_md_queue_fail;
	}

	/* Suspend the device so that we can bind it to the table. */
	if (dm_suspend(md, 0)) {
	DMDEBUG("failed to suspend the device pre-bind");
	goto suspend_fail;
	}

	/* Bind the table to the device. This is the only way to associate
	* md->map with the table and set the disk capacity directly. */
	if (dm_swap_table(md, table)) { /* should return NULL. */
	DMDEBUG("failed to bind the device to the table");
	goto table_bind_fail;
	}

	/* Finally, resume and the device should be ready. */
	if (dm_resume(md)) {
	DMDEBUG("failed to resume the device");
	goto resume_fail;
	}

	/* Export the dm device via the ioctl interface */
	if (!strcmp(DM_NO_UUID, dm_setup_args.uuid))
	uuid = NULL;
	if (dm_ioctl_export(md, dm_setup_args.name, uuid)) {
	DMDEBUG("failed to export device with given name and uuid");
	goto export_fail;
	}
	printk(KERN_INFO "dm: dm-%d is ready\n", dm_setup_args.minor);

	dm_unlock_md_type(md);
	dm_setup_cleanup();
	return;

	export_fail:
	resume_fail:
	table_bind_fail:
	suspend_fail:
	setup_md_queue_fail:
	table_complete_fail:
	add_target_fail:
	dm_unlock_md_type(md);
	dm_table_create_fail:
	dm_put(md);
	dm_create_fail:
	dm_setup_cleanup();
	parse_fail:
	printk(KERN_WARNING "dm: starting dm-%d (%s) failed\n",
	dm_setup_args.minor, dm_setup_args.name);
	}

	__setup("dm=", dm_setup);

	void __init dm_run_setup(void)
	{
	if (!dm_early_setup)
	return;
	printk(KERN_INFO "dm: attempting early device configuration.\n");
	dm_setup_drive();
	}