dm-ioctl.c 36.4 KB
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/*
 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
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 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
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 *
 * This file is released under the GPL.
 */

#include "dm.h"

#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/dm-ioctl.h>
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#include <linux/hdreg.h>
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#include <linux/compat.h>
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#include <asm/uaccess.h>

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#define DM_MSG_PREFIX "ioctl"
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#define DM_DRIVER_EMAIL "dm-devel@redhat.com"

/*-----------------------------------------------------------------
 * The ioctl interface needs to be able to look up devices by
 * name or uuid.
 *---------------------------------------------------------------*/
struct hash_cell {
	struct list_head name_list;
	struct list_head uuid_list;

	char *name;
	char *uuid;
	struct mapped_device *md;
	struct dm_table *new_map;
};

struct vers_iter {
    size_t param_size;
    struct dm_target_versions *vers, *old_vers;
    char *end;
    uint32_t flags;
};


#define NUM_BUCKETS 64
#define MASK_BUCKETS (NUM_BUCKETS - 1)
static struct list_head _name_buckets[NUM_BUCKETS];
static struct list_head _uuid_buckets[NUM_BUCKETS];

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static void dm_hash_remove_all(int keep_open_devices);
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/*
 * Guards access to both hash tables.
 */
static DECLARE_RWSEM(_hash_lock);

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/*
 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
 */
static DEFINE_MUTEX(dm_hash_cells_mutex);

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static void init_buckets(struct list_head *buckets)
{
	unsigned int i;

	for (i = 0; i < NUM_BUCKETS; i++)
		INIT_LIST_HEAD(buckets + i);
}

static int dm_hash_init(void)
{
	init_buckets(_name_buckets);
	init_buckets(_uuid_buckets);
	return 0;
}

static void dm_hash_exit(void)
{
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	dm_hash_remove_all(0);
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}

/*-----------------------------------------------------------------
 * Hash function:
 * We're not really concerned with the str hash function being
 * fast since it's only used by the ioctl interface.
 *---------------------------------------------------------------*/
static unsigned int hash_str(const char *str)
{
	const unsigned int hash_mult = 2654435387U;
	unsigned int h = 0;

	while (*str)
		h = (h + (unsigned int) *str++) * hash_mult;

	return h & MASK_BUCKETS;
}

/*-----------------------------------------------------------------
 * Code for looking up a device by name
 *---------------------------------------------------------------*/
static struct hash_cell *__get_name_cell(const char *str)
{
	struct hash_cell *hc;
	unsigned int h = hash_str(str);

	list_for_each_entry (hc, _name_buckets + h, name_list)
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		if (!strcmp(hc->name, str)) {
			dm_get(hc->md);
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			return hc;
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		}
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	return NULL;
}

static struct hash_cell *__get_uuid_cell(const char *str)
{
	struct hash_cell *hc;
	unsigned int h = hash_str(str);

	list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
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		if (!strcmp(hc->uuid, str)) {
			dm_get(hc->md);
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			return hc;
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		}
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	return NULL;
}

/*-----------------------------------------------------------------
 * Inserting, removing and renaming a device.
 *---------------------------------------------------------------*/
static struct hash_cell *alloc_cell(const char *name, const char *uuid,
				    struct mapped_device *md)
{
	struct hash_cell *hc;

	hc = kmalloc(sizeof(*hc), GFP_KERNEL);
	if (!hc)
		return NULL;

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	hc->name = kstrdup(name, GFP_KERNEL);
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	if (!hc->name) {
		kfree(hc);
		return NULL;
	}

	if (!uuid)
		hc->uuid = NULL;

	else {
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		hc->uuid = kstrdup(uuid, GFP_KERNEL);
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		if (!hc->uuid) {
			kfree(hc->name);
			kfree(hc);
			return NULL;
		}
	}

	INIT_LIST_HEAD(&hc->name_list);
	INIT_LIST_HEAD(&hc->uuid_list);
	hc->md = md;
	hc->new_map = NULL;
	return hc;
}

static void free_cell(struct hash_cell *hc)
{
	if (hc) {
		kfree(hc->name);
		kfree(hc->uuid);
		kfree(hc);
	}
}

/*
 * The kdev_t and uuid of a device can never change once it is
 * initially inserted.
 */
static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
{
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	struct hash_cell *cell, *hc;
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	/*
	 * Allocate the new cells.
	 */
	cell = alloc_cell(name, uuid, md);
	if (!cell)
		return -ENOMEM;

	/*
	 * Insert the cell into both hash tables.
	 */
	down_write(&_hash_lock);
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	hc = __get_name_cell(name);
	if (hc) {
		dm_put(hc->md);
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		goto bad;
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	}
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	list_add(&cell->name_list, _name_buckets + hash_str(name));

	if (uuid) {
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		hc = __get_uuid_cell(uuid);
		if (hc) {
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			list_del(&cell->name_list);
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			dm_put(hc->md);
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			goto bad;
		}
		list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
	}
	dm_get(md);
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	mutex_lock(&dm_hash_cells_mutex);
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	dm_set_mdptr(md, cell);
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	mutex_unlock(&dm_hash_cells_mutex);
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	up_write(&_hash_lock);

	return 0;

 bad:
	up_write(&_hash_lock);
	free_cell(cell);
	return -EBUSY;
}

static void __hash_remove(struct hash_cell *hc)
{
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	struct dm_table *table;

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	/* remove from the dev hash */
	list_del(&hc->uuid_list);
	list_del(&hc->name_list);
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	mutex_lock(&dm_hash_cells_mutex);
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	dm_set_mdptr(hc->md, NULL);
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	mutex_unlock(&dm_hash_cells_mutex);
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	table = dm_get_live_table(hc->md);
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	if (table) {
		dm_table_event(table);
		dm_table_put(table);
	}

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	if (hc->new_map)
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		dm_table_destroy(hc->new_map);
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	dm_put(hc->md);
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	free_cell(hc);
}

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static void dm_hash_remove_all(int keep_open_devices)
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{
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	int i, dev_skipped;
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	struct hash_cell *hc;
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	struct mapped_device *md;

retry:
	dev_skipped = 0;
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	down_write(&_hash_lock);
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	for (i = 0; i < NUM_BUCKETS; i++) {
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		list_for_each_entry(hc, _name_buckets + i, name_list) {
			md = hc->md;
			dm_get(md);
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			if (keep_open_devices && dm_lock_for_deletion(md)) {
				dm_put(md);
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				dev_skipped++;
				continue;
			}
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			__hash_remove(hc);
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			up_write(&_hash_lock);
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			dm_put(md);
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			if (likely(keep_open_devices))
				dm_destroy(md);
			else
				dm_destroy_immediate(md);
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			/*
			 * Some mapped devices may be using other mapped
			 * devices, so repeat until we make no further
			 * progress.  If a new mapped device is created
			 * here it will also get removed.
			 */
			goto retry;
		}
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	}

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	up_write(&_hash_lock);
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	if (dev_skipped)
		DMWARN("remove_all left %d open device(s)", dev_skipped);
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}

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/*
 * Set the uuid of a hash_cell that isn't already set.
 */
static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
{
	mutex_lock(&dm_hash_cells_mutex);
	hc->uuid = new_uuid;
	mutex_unlock(&dm_hash_cells_mutex);

	list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
}

/*
 * Changes the name of a hash_cell and returns the old name for
 * the caller to free.
 */
static char *__change_cell_name(struct hash_cell *hc, char *new_name)
{
	char *old_name;

	/*
	 * Rename and move the name cell.
	 */
	list_del(&hc->name_list);
	old_name = hc->name;

	mutex_lock(&dm_hash_cells_mutex);
	hc->name = new_name;
	mutex_unlock(&dm_hash_cells_mutex);

	list_add(&hc->name_list, _name_buckets + hash_str(new_name));

	return old_name;
}

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static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
					    const char *new)
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{
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	char *new_data, *old_name = NULL;
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	struct hash_cell *hc;
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	struct dm_table *table;
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	struct mapped_device *md;
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	unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
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	/*
	 * duplicate new.
	 */
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	new_data = kstrdup(new, GFP_KERNEL);
	if (!new_data)
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		return ERR_PTR(-ENOMEM);
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	down_write(&_hash_lock);

	/*
	 * Is new free ?
	 */
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	if (change_uuid)
		hc = __get_uuid_cell(new);
	else
		hc = __get_name_cell(new);

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	if (hc) {
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		DMWARN("Unable to change %s on mapped device %s to one that "
		       "already exists: %s",
		       change_uuid ? "uuid" : "name",
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		       param->name, new);
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		dm_put(hc->md);
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		up_write(&_hash_lock);
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		kfree(new_data);
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		return ERR_PTR(-EBUSY);
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	}

	/*
	 * Is there such a device as 'old' ?
	 */
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	hc = __get_name_cell(param->name);
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	if (!hc) {
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		DMWARN("Unable to rename non-existent device, %s to %s%s",
		       param->name, change_uuid ? "uuid " : "", new);
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		up_write(&_hash_lock);
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		kfree(new_data);
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		return ERR_PTR(-ENXIO);
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	}

	/*
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	 * Does this device already have a uuid?
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	 */
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	if (change_uuid && hc->uuid) {
		DMWARN("Unable to change uuid of mapped device %s to %s "
		       "because uuid is already set to %s",
		       param->name, new, hc->uuid);
		dm_put(hc->md);
		up_write(&_hash_lock);
		kfree(new_data);
		return ERR_PTR(-EINVAL);
	}

	if (change_uuid)
		__set_cell_uuid(hc, new_data);
	else
		old_name = __change_cell_name(hc, new_data);
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	/*
	 * Wake up any dm event waiters.
	 */
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	table = dm_get_live_table(hc->md);
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	if (table) {
		dm_table_event(table);
		dm_table_put(table);
	}

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	if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
		param->flags |= DM_UEVENT_GENERATED_FLAG;
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	md = hc->md;
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	up_write(&_hash_lock);
	kfree(old_name);
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	return md;
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}

/*-----------------------------------------------------------------
 * Implementation of the ioctl commands
 *---------------------------------------------------------------*/
/*
 * All the ioctl commands get dispatched to functions with this
 * prototype.
 */
typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);

static int remove_all(struct dm_ioctl *param, size_t param_size)
{
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	dm_hash_remove_all(1);
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	param->data_size = 0;
	return 0;
}

/*
 * Round up the ptr to an 8-byte boundary.
 */
#define ALIGN_MASK 7
static inline void *align_ptr(void *ptr)
{
	return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
}

/*
 * Retrieves the data payload buffer from an already allocated
 * struct dm_ioctl.
 */
static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
			       size_t *len)
{
	param->data_start = align_ptr(param + 1) - (void *) param;

	if (param->data_start < param_size)
		*len = param_size - param->data_start;
	else
		*len = 0;

	return ((void *) param) + param->data_start;
}

static int list_devices(struct dm_ioctl *param, size_t param_size)
{
	unsigned int i;
	struct hash_cell *hc;
	size_t len, needed = 0;
	struct gendisk *disk;
	struct dm_name_list *nl, *old_nl = NULL;

	down_write(&_hash_lock);

	/*
	 * Loop through all the devices working out how much
	 * space we need.
	 */
	for (i = 0; i < NUM_BUCKETS; i++) {
		list_for_each_entry (hc, _name_buckets + i, name_list) {
			needed += sizeof(struct dm_name_list);
			needed += strlen(hc->name) + 1;
			needed += ALIGN_MASK;
		}
	}

	/*
	 * Grab our output buffer.
	 */
	nl = get_result_buffer(param, param_size, &len);
	if (len < needed) {
		param->flags |= DM_BUFFER_FULL_FLAG;
		goto out;
	}
	param->data_size = param->data_start + needed;

	nl->dev = 0;	/* Flags no data */

	/*
	 * Now loop through filling out the names.
	 */
	for (i = 0; i < NUM_BUCKETS; i++) {
		list_for_each_entry (hc, _name_buckets + i, name_list) {
			if (old_nl)
				old_nl->next = (uint32_t) ((void *) nl -
							   (void *) old_nl);
			disk = dm_disk(hc->md);
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			nl->dev = huge_encode_dev(disk_devt(disk));
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			nl->next = 0;
			strcpy(nl->name, hc->name);

			old_nl = nl;
			nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
		}
	}

 out:
	up_write(&_hash_lock);
	return 0;
}

static void list_version_get_needed(struct target_type *tt, void *needed_param)
{
    size_t *needed = needed_param;

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    *needed += sizeof(struct dm_target_versions);
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    *needed += strlen(tt->name);
    *needed += ALIGN_MASK;
}

static void list_version_get_info(struct target_type *tt, void *param)
{
    struct vers_iter *info = param;

    /* Check space - it might have changed since the first iteration */
    if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
	info->end) {

	info->flags = DM_BUFFER_FULL_FLAG;
	return;
    }

    if (info->old_vers)
	info->old_vers->next = (uint32_t) ((void *)info->vers -
					   (void *)info->old_vers);
    info->vers->version[0] = tt->version[0];
    info->vers->version[1] = tt->version[1];
    info->vers->version[2] = tt->version[2];
    info->vers->next = 0;
    strcpy(info->vers->name, tt->name);

    info->old_vers = info->vers;
    info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
}

static int list_versions(struct dm_ioctl *param, size_t param_size)
{
	size_t len, needed = 0;
	struct dm_target_versions *vers;
	struct vers_iter iter_info;

	/*
	 * Loop through all the devices working out how much
	 * space we need.
	 */
	dm_target_iterate(list_version_get_needed, &needed);

	/*
	 * Grab our output buffer.
	 */
	vers = get_result_buffer(param, param_size, &len);
	if (len < needed) {
		param->flags |= DM_BUFFER_FULL_FLAG;
		goto out;
	}
	param->data_size = param->data_start + needed;

	iter_info.param_size = param_size;
	iter_info.old_vers = NULL;
	iter_info.vers = vers;
	iter_info.flags = 0;
	iter_info.end = (char *)vers+len;

	/*
	 * Now loop through filling out the names & versions.
	 */
	dm_target_iterate(list_version_get_info, &iter_info);
	param->flags |= iter_info.flags;

 out:
	return 0;
}

static int check_name(const char *name)
{
	if (strchr(name, '/')) {
		DMWARN("invalid device name");
		return -EINVAL;
	}

	return 0;
}

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/*
 * On successful return, the caller must not attempt to acquire
 * _hash_lock without first calling dm_table_put, because dm_table_destroy
 * waits for this dm_table_put and could be called under this lock.
 */
static struct dm_table *dm_get_inactive_table(struct mapped_device *md)
{
	struct hash_cell *hc;
	struct dm_table *table = NULL;

	down_read(&_hash_lock);
	hc = dm_get_mdptr(md);
	if (!hc || hc->md != md) {
		DMWARN("device has been removed from the dev hash table.");
		goto out;
	}

	table = hc->new_map;
	if (table)
		dm_table_get(table);

out:
	up_read(&_hash_lock);

	return table;
}

static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
						      struct dm_ioctl *param)
{
	return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
		dm_get_inactive_table(md) : dm_get_live_table(md);
}

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/*
 * Fills in a dm_ioctl structure, ready for sending back to
 * userland.
 */
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static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
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{
	struct gendisk *disk = dm_disk(md);
	struct dm_table *table;

	param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
			  DM_ACTIVE_PRESENT_FLAG);

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	if (dm_suspended_md(md))
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		param->flags |= DM_SUSPEND_FLAG;

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	param->dev = huge_encode_dev(disk_devt(disk));
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	/*
	 * Yes, this will be out of date by the time it gets back
	 * to userland, but it is still very useful for
	 * debugging.
	 */
	param->open_count = dm_open_count(md);
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	param->event_nr = dm_get_event_nr(md);
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	param->target_count = 0;
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	table = dm_get_live_table(md);
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	if (table) {
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		if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
			if (get_disk_ro(disk))
				param->flags |= DM_READONLY_FLAG;
			param->target_count = dm_table_get_num_targets(table);
		}
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		dm_table_put(table);
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		param->flags |= DM_ACTIVE_PRESENT_FLAG;
	}

	if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
		table = dm_get_inactive_table(md);
		if (table) {
			if (!(dm_table_get_mode(table) & FMODE_WRITE))
				param->flags |= DM_READONLY_FLAG;
			param->target_count = dm_table_get_num_targets(table);
			dm_table_put(table);
		}
	}
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}

static int dev_create(struct dm_ioctl *param, size_t param_size)
{
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	int r, m = DM_ANY_MINOR;
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	struct mapped_device *md;

	r = check_name(param->name);
	if (r)
		return r;

	if (param->flags & DM_PERSISTENT_DEV_FLAG)
694
		m = MINOR(huge_decode_dev(param->dev));
L
Linus Torvalds 已提交
695

696
	r = dm_create(m, &md);
L
Linus Torvalds 已提交
697 698 699 700
	if (r)
		return r;

	r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
701 702 703 704 705
	if (r) {
		dm_put(md);
		dm_destroy(md);
		return r;
	}
L
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706 707 708

	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;

709 710
	__dev_status(md, param);

L
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711 712
	dm_put(md);

713
	return 0;
L
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714 715 716 717 718
}

/*
 * Always use UUID for lookups if it's present, otherwise use name or dev.
 */
719
static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
L
Linus Torvalds 已提交
720
{
A
Alasdair G Kergon 已提交
721 722 723
	struct mapped_device *md;
	void *mdptr = NULL;

L
Linus Torvalds 已提交
724 725
	if (*param->uuid)
		return __get_uuid_cell(param->uuid);
A
Alasdair G Kergon 已提交
726 727

	if (*param->name)
L
Linus Torvalds 已提交
728
		return __get_name_cell(param->name);
A
Alasdair G Kergon 已提交
729 730

	md = dm_get_md(huge_decode_dev(param->dev));
731 732 733 734 735 736
	if (!md)
		goto out;

	mdptr = dm_get_mdptr(md);
	if (!mdptr)
		dm_put(md);
A
Alasdair G Kergon 已提交
737

738
out:
A
Alasdair G Kergon 已提交
739
	return mdptr;
L
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740 741
}

742
static struct mapped_device *find_device(struct dm_ioctl *param)
L
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743 744 745 746 747 748 749 750 751 752 753 754 755
{
	struct hash_cell *hc;
	struct mapped_device *md = NULL;

	down_read(&_hash_lock);
	hc = __find_device_hash_cell(param);
	if (hc) {
		md = hc->md;

		/*
		 * Sneakily write in both the name and the uuid
		 * while we have the cell.
		 */
R
Roel Kluin 已提交
756
		strlcpy(param->name, hc->name, sizeof(param->name));
L
Linus Torvalds 已提交
757
		if (hc->uuid)
R
Roel Kluin 已提交
758
			strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
L
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759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774
		else
			param->uuid[0] = '\0';

		if (hc->new_map)
			param->flags |= DM_INACTIVE_PRESENT_FLAG;
		else
			param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
	}
	up_read(&_hash_lock);

	return md;
}

static int dev_remove(struct dm_ioctl *param, size_t param_size)
{
	struct hash_cell *hc;
775
	struct mapped_device *md;
776
	int r;
L
Linus Torvalds 已提交
777 778 779 780 781

	down_write(&_hash_lock);
	hc = __find_device_hash_cell(param);

	if (!hc) {
782
		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
L
Linus Torvalds 已提交
783 784 785 786
		up_write(&_hash_lock);
		return -ENXIO;
	}

787 788
	md = hc->md;

789 790 791 792 793
	/*
	 * Ensure the device is not open and nothing further can open it.
	 */
	r = dm_lock_for_deletion(md);
	if (r) {
794
		DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
795 796 797 798 799
		up_write(&_hash_lock);
		dm_put(md);
		return r;
	}

L
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800 801
	__hash_remove(hc);
	up_write(&_hash_lock);
M
Milan Broz 已提交
802

803 804
	if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
		param->flags |= DM_UEVENT_GENERATED_FLAG;
M
Milan Broz 已提交
805

806
	dm_put(md);
807
	dm_destroy(md);
L
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808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826
	return 0;
}

/*
 * Check a string doesn't overrun the chunk of
 * memory we copied from userland.
 */
static int invalid_str(char *str, void *end)
{
	while ((void *) str < end)
		if (!*str++)
			return 0;

	return -EINVAL;
}

static int dev_rename(struct dm_ioctl *param, size_t param_size)
{
	int r;
827
	char *new_data = (char *) param + param->data_start;
828
	struct mapped_device *md;
829
	unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
L
Linus Torvalds 已提交
830

831 832 833 834
	if (new_data < param->data ||
	    invalid_str(new_data, (void *) param + param_size) ||
	    strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
		DMWARN("Invalid new mapped device name or uuid string supplied.");
L
Linus Torvalds 已提交
835 836 837
		return -EINVAL;
	}

838 839 840 841 842
	if (!change_uuid) {
		r = check_name(new_data);
		if (r)
			return r;
	}
L
Linus Torvalds 已提交
843

844
	md = dm_hash_rename(param, new_data);
845 846
	if (IS_ERR(md))
		return PTR_ERR(md);
847

848 849 850 851
	__dev_status(md, param);
	dm_put(md);

	return 0;
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Linus Torvalds 已提交
852 853
}

D
Darrick J. Wong 已提交
854 855 856 857 858 859 860 861 862 863 864 865
static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
{
	int r = -EINVAL, x;
	struct mapped_device *md;
	struct hd_geometry geometry;
	unsigned long indata[4];
	char *geostr = (char *) param + param->data_start;

	md = find_device(param);
	if (!md)
		return -ENXIO;

A
Alasdair G Kergon 已提交
866
	if (geostr < param->data ||
D
Darrick J. Wong 已提交
867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899
	    invalid_str(geostr, (void *) param + param_size)) {
		DMWARN("Invalid geometry supplied.");
		goto out;
	}

	x = sscanf(geostr, "%lu %lu %lu %lu", indata,
		   indata + 1, indata + 2, indata + 3);

	if (x != 4) {
		DMWARN("Unable to interpret geometry settings.");
		goto out;
	}

	if (indata[0] > 65535 || indata[1] > 255 ||
	    indata[2] > 255 || indata[3] > ULONG_MAX) {
		DMWARN("Geometry exceeds range limits.");
		goto out;
	}

	geometry.cylinders = indata[0];
	geometry.heads = indata[1];
	geometry.sectors = indata[2];
	geometry.start = indata[3];

	r = dm_set_geometry(md, &geometry);

	param->data_size = 0;

out:
	dm_put(md);
	return r;
}

L
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static int do_suspend(struct dm_ioctl *param)
{
	int r = 0;
903
	unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
L
Linus Torvalds 已提交
904 905 906 907 908 909
	struct mapped_device *md;

	md = find_device(param);
	if (!md)
		return -ENXIO;

910
	if (param->flags & DM_SKIP_LOCKFS_FLAG)
911
		suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
912 913
	if (param->flags & DM_NOFLUSH_FLAG)
		suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
914

915
	if (!dm_suspended_md(md)) {
916
		r = dm_suspend(md, suspend_flags);
917 918 919
		if (r)
			goto out;
	}
L
Linus Torvalds 已提交
920

921
	__dev_status(md, param);
L
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922

923
out:
L
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924
	dm_put(md);
925

L
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926 927 928 929 930 931
	return r;
}

static int do_resume(struct dm_ioctl *param)
{
	int r = 0;
932
	unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
L
Linus Torvalds 已提交
933 934
	struct hash_cell *hc;
	struct mapped_device *md;
935
	struct dm_table *new_map, *old_map = NULL;
L
Linus Torvalds 已提交
936 937 938 939 940

	down_write(&_hash_lock);

	hc = __find_device_hash_cell(param);
	if (!hc) {
941
		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
L
Linus Torvalds 已提交
942 943 944 945 946 947 948 949 950 951 952 953 954 955 956
		up_write(&_hash_lock);
		return -ENXIO;
	}

	md = hc->md;

	new_map = hc->new_map;
	hc->new_map = NULL;
	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;

	up_write(&_hash_lock);

	/* Do we need to load a new map ? */
	if (new_map) {
		/* Suspend if it isn't already suspended */
957
		if (param->flags & DM_SKIP_LOCKFS_FLAG)
958
			suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
959 960
		if (param->flags & DM_NOFLUSH_FLAG)
			suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
961
		if (!dm_suspended_md(md))
962
			dm_suspend(md, suspend_flags);
L
Linus Torvalds 已提交
963

964 965
		old_map = dm_swap_table(md, new_map);
		if (IS_ERR(old_map)) {
966
			dm_table_destroy(new_map);
L
Linus Torvalds 已提交
967
			dm_put(md);
968
			return PTR_ERR(old_map);
L
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969 970 971 972 973 974 975 976
		}

		if (dm_table_get_mode(new_map) & FMODE_WRITE)
			set_disk_ro(dm_disk(md), 0);
		else
			set_disk_ro(dm_disk(md), 1);
	}

977
	if (dm_suspended_md(md)) {
L
Linus Torvalds 已提交
978
		r = dm_resume(md);
979 980
		if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
			param->flags |= DM_UEVENT_GENERATED_FLAG;
981
	}
L
Linus Torvalds 已提交
982

983 984
	if (old_map)
		dm_table_destroy(old_map);
M
Milan Broz 已提交
985

986
	if (!r)
987
		__dev_status(md, param);
L
Linus Torvalds 已提交
988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016

	dm_put(md);
	return r;
}

/*
 * Set or unset the suspension state of a device.
 * If the device already is in the requested state we just return its status.
 */
static int dev_suspend(struct dm_ioctl *param, size_t param_size)
{
	if (param->flags & DM_SUSPEND_FLAG)
		return do_suspend(param);

	return do_resume(param);
}

/*
 * Copies device info back to user space, used by
 * the create and info ioctls.
 */
static int dev_status(struct dm_ioctl *param, size_t param_size)
{
	struct mapped_device *md;

	md = find_device(param);
	if (!md)
		return -ENXIO;

1017
	__dev_status(md, param);
L
Linus Torvalds 已提交
1018
	dm_put(md);
1019 1020

	return 0;
L
Linus Torvalds 已提交
1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094
}

/*
 * Build up the status struct for each target
 */
static void retrieve_status(struct dm_table *table,
			    struct dm_ioctl *param, size_t param_size)
{
	unsigned int i, num_targets;
	struct dm_target_spec *spec;
	char *outbuf, *outptr;
	status_type_t type;
	size_t remaining, len, used = 0;

	outptr = outbuf = get_result_buffer(param, param_size, &len);

	if (param->flags & DM_STATUS_TABLE_FLAG)
		type = STATUSTYPE_TABLE;
	else
		type = STATUSTYPE_INFO;

	/* Get all the target info */
	num_targets = dm_table_get_num_targets(table);
	for (i = 0; i < num_targets; i++) {
		struct dm_target *ti = dm_table_get_target(table, i);

		remaining = len - (outptr - outbuf);
		if (remaining <= sizeof(struct dm_target_spec)) {
			param->flags |= DM_BUFFER_FULL_FLAG;
			break;
		}

		spec = (struct dm_target_spec *) outptr;

		spec->status = 0;
		spec->sector_start = ti->begin;
		spec->length = ti->len;
		strncpy(spec->target_type, ti->type->name,
			sizeof(spec->target_type));

		outptr += sizeof(struct dm_target_spec);
		remaining = len - (outptr - outbuf);
		if (remaining <= 0) {
			param->flags |= DM_BUFFER_FULL_FLAG;
			break;
		}

		/* Get the status/table string from the target driver */
		if (ti->type->status) {
			if (ti->type->status(ti, type, outptr, remaining)) {
				param->flags |= DM_BUFFER_FULL_FLAG;
				break;
			}
		} else
			outptr[0] = '\0';

		outptr += strlen(outptr) + 1;
		used = param->data_start + (outptr - outbuf);

		outptr = align_ptr(outptr);
		spec->next = outptr - outbuf;
	}

	if (used)
		param->data_size = used;

	param->target_count = num_targets;
}

/*
 * Wait for a device to report an event
 */
static int dev_wait(struct dm_ioctl *param, size_t param_size)
{
1095
	int r = 0;
L
Linus Torvalds 已提交
1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
	struct mapped_device *md;
	struct dm_table *table;

	md = find_device(param);
	if (!md)
		return -ENXIO;

	/*
	 * Wait for a notification event
	 */
	if (dm_wait_event(md, param->event_nr)) {
		r = -ERESTARTSYS;
		goto out;
	}

	/*
	 * The userland program is going to want to know what
	 * changed to trigger the event, so we may as well tell
	 * him and save an ioctl.
	 */
1116
	__dev_status(md, param);
L
Linus Torvalds 已提交
1117

1118
	table = dm_get_live_or_inactive_table(md, param);
L
Linus Torvalds 已提交
1119 1120 1121 1122 1123
	if (table) {
		retrieve_status(table, param, param_size);
		dm_table_put(table);
	}

1124
out:
L
Linus Torvalds 已提交
1125
	dm_put(md);
1126

L
Linus Torvalds 已提交
1127 1128 1129
	return r;
}

1130
static inline fmode_t get_mode(struct dm_ioctl *param)
L
Linus Torvalds 已提交
1131
{
1132
	fmode_t mode = FMODE_READ | FMODE_WRITE;
L
Linus Torvalds 已提交
1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194

	if (param->flags & DM_READONLY_FLAG)
		mode = FMODE_READ;

	return mode;
}

static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
		       struct dm_target_spec **spec, char **target_params)
{
	*spec = (struct dm_target_spec *) ((unsigned char *) last + next);
	*target_params = (char *) (*spec + 1);

	if (*spec < (last + 1))
		return -EINVAL;

	return invalid_str(*target_params, end);
}

static int populate_table(struct dm_table *table,
			  struct dm_ioctl *param, size_t param_size)
{
	int r;
	unsigned int i = 0;
	struct dm_target_spec *spec = (struct dm_target_spec *) param;
	uint32_t next = param->data_start;
	void *end = (void *) param + param_size;
	char *target_params;

	if (!param->target_count) {
		DMWARN("populate_table: no targets specified");
		return -EINVAL;
	}

	for (i = 0; i < param->target_count; i++) {

		r = next_target(spec, next, end, &spec, &target_params);
		if (r) {
			DMWARN("unable to find target");
			return r;
		}

		r = dm_table_add_target(table, spec->target_type,
					(sector_t) spec->sector_start,
					(sector_t) spec->length,
					target_params);
		if (r) {
			DMWARN("error adding target to table");
			return r;
		}

		next = spec->next;
	}

	return dm_table_complete(table);
}

static int table_load(struct dm_ioctl *param, size_t param_size)
{
	int r;
	struct hash_cell *hc;
	struct dm_table *t;
M
Mike Anderson 已提交
1195 1196 1197 1198 1199
	struct mapped_device *md;

	md = find_device(param);
	if (!md)
		return -ENXIO;
L
Linus Torvalds 已提交
1200

M
Mike Anderson 已提交
1201
	r = dm_table_create(&t, get_mode(param), param->target_count, md);
L
Linus Torvalds 已提交
1202
	if (r)
M
Mike Anderson 已提交
1203
		goto out;
L
Linus Torvalds 已提交
1204 1205 1206

	r = populate_table(t, param, param_size);
	if (r) {
1207
		dm_table_destroy(t);
M
Mike Anderson 已提交
1208
		goto out;
L
Linus Torvalds 已提交
1209 1210
	}

1211
	/* Protect md->type and md->queue against concurrent table loads. */
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222
	dm_lock_md_type(md);
	if (dm_get_md_type(md) == DM_TYPE_NONE)
		/* Initial table load: acquire type of table. */
		dm_set_md_type(md, dm_table_get_type(t));
	else if (dm_get_md_type(md) != dm_table_get_type(t)) {
		DMWARN("can't change device type after initial table load.");
		dm_table_destroy(t);
		dm_unlock_md_type(md);
		r = -EINVAL;
		goto out;
	}
1223 1224 1225 1226 1227 1228 1229 1230 1231

	/* setup md->queue to reflect md's type (may block) */
	r = dm_setup_md_queue(md);
	if (r) {
		DMWARN("unable to set up device queue for new table.");
		dm_table_destroy(t);
		dm_unlock_md_type(md);
		goto out;
	}
1232 1233 1234
	dm_unlock_md_type(md);

	/* stage inactive table */
L
Linus Torvalds 已提交
1235
	down_write(&_hash_lock);
M
Mike Anderson 已提交
1236 1237 1238
	hc = dm_get_mdptr(md);
	if (!hc || hc->md != md) {
		DMWARN("device has been removed from the dev hash table.");
1239
		dm_table_destroy(t);
M
Mike Anderson 已提交
1240 1241 1242
		up_write(&_hash_lock);
		r = -ENXIO;
		goto out;
L
Linus Torvalds 已提交
1243 1244 1245
	}

	if (hc->new_map)
1246
		dm_table_destroy(hc->new_map);
L
Linus Torvalds 已提交
1247
	hc->new_map = t;
M
Mike Anderson 已提交
1248 1249
	up_write(&_hash_lock);

L
Linus Torvalds 已提交
1250
	param->flags |= DM_INACTIVE_PRESENT_FLAG;
1251
	__dev_status(md, param);
M
Mike Anderson 已提交
1252 1253 1254

out:
	dm_put(md);
L
Linus Torvalds 已提交
1255 1256 1257 1258 1259 1260 1261

	return r;
}

static int table_clear(struct dm_ioctl *param, size_t param_size)
{
	struct hash_cell *hc;
1262
	struct mapped_device *md;
L
Linus Torvalds 已提交
1263 1264 1265 1266 1267

	down_write(&_hash_lock);

	hc = __find_device_hash_cell(param);
	if (!hc) {
1268
		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
L
Linus Torvalds 已提交
1269 1270 1271 1272 1273
		up_write(&_hash_lock);
		return -ENXIO;
	}

	if (hc->new_map) {
1274
		dm_table_destroy(hc->new_map);
L
Linus Torvalds 已提交
1275 1276 1277 1278 1279
		hc->new_map = NULL;
	}

	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;

1280
	__dev_status(hc->md, param);
1281
	md = hc->md;
L
Linus Torvalds 已提交
1282
	up_write(&_hash_lock);
1283
	dm_put(md);
1284 1285

	return 0;
L
Linus Torvalds 已提交
1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296
}

/*
 * Retrieves a list of devices used by a particular dm device.
 */
static void retrieve_deps(struct dm_table *table,
			  struct dm_ioctl *param, size_t param_size)
{
	unsigned int count = 0;
	struct list_head *tmp;
	size_t len, needed;
M
Mikulas Patocka 已提交
1297
	struct dm_dev_internal *dd;
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Linus Torvalds 已提交
1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
	struct dm_target_deps *deps;

	deps = get_result_buffer(param, param_size, &len);

	/*
	 * Count the devices.
	 */
	list_for_each (tmp, dm_table_get_devices(table))
		count++;

	/*
	 * Check we have enough space.
	 */
	needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
	if (len < needed) {
		param->flags |= DM_BUFFER_FULL_FLAG;
		return;
	}

	/*
	 * Fill in the devices.
	 */
	deps->count = count;
	count = 0;
	list_for_each_entry (dd, dm_table_get_devices(table), list)
M
Mikulas Patocka 已提交
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		deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
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1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336

	param->data_size = param->data_start + needed;
}

static int table_deps(struct dm_ioctl *param, size_t param_size)
{
	struct mapped_device *md;
	struct dm_table *table;

	md = find_device(param);
	if (!md)
		return -ENXIO;

1337
	__dev_status(md, param);
L
Linus Torvalds 已提交
1338

1339
	table = dm_get_live_or_inactive_table(md, param);
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Linus Torvalds 已提交
1340 1341 1342 1343 1344 1345
	if (table) {
		retrieve_deps(table, param, param_size);
		dm_table_put(table);
	}

	dm_put(md);
1346 1347

	return 0;
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Linus Torvalds 已提交
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}

/*
 * Return the status of a device as a text string for each
 * target.
 */
static int table_status(struct dm_ioctl *param, size_t param_size)
{
	struct mapped_device *md;
	struct dm_table *table;

	md = find_device(param);
	if (!md)
		return -ENXIO;

1363
	__dev_status(md, param);
L
Linus Torvalds 已提交
1364

1365
	table = dm_get_live_or_inactive_table(md, param);
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1366 1367 1368 1369 1370 1371
	if (table) {
		retrieve_status(table, param, param_size);
		dm_table_put(table);
	}

	dm_put(md);
1372 1373

	return 0;
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}

/*
 * Pass a message to the target that's at the supplied device offset.
 */
static int target_message(struct dm_ioctl *param, size_t param_size)
{
	int r, argc;
	char **argv;
	struct mapped_device *md;
	struct dm_table *table;
	struct dm_target *ti;
	struct dm_target_msg *tmsg = (void *) param + param->data_start;

	md = find_device(param);
	if (!md)
		return -ENXIO;

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Milan Broz 已提交
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	if (tmsg < (struct dm_target_msg *) param->data ||
L
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	    invalid_str(tmsg->message, (void *) param + param_size)) {
		DMWARN("Invalid target message parameters.");
		r = -EINVAL;
		goto out;
	}

	r = dm_split_args(&argc, &argv, tmsg->message);
	if (r) {
		DMWARN("Failed to split target message parameters");
		goto out;
	}

1405 1406 1407 1408 1409
	if (!argc) {
		DMWARN("Empty message received.");
		goto out;
	}

1410
	table = dm_get_live_table(md);
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	if (!table)
		goto out_argv;

1414 1415 1416 1417 1418
	if (dm_deleting_md(md)) {
		r = -ENXIO;
		goto out_table;
	}

1419 1420
	ti = dm_table_find_target(table, tmsg->sector);
	if (!dm_target_is_valid(ti)) {
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		DMWARN("Target message sector outside device.");
		r = -EINVAL;
1423
	} else if (ti->type->message)
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		r = ti->type->message(ti, argc, argv);
	else {
		DMWARN("Target type does not support messages");
		r = -EINVAL;
	}

1430
 out_table:
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1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467
	dm_table_put(table);
 out_argv:
	kfree(argv);
 out:
	param->data_size = 0;
	dm_put(md);
	return r;
}

/*-----------------------------------------------------------------
 * Implementation of open/close/ioctl on the special char
 * device.
 *---------------------------------------------------------------*/
static ioctl_fn lookup_ioctl(unsigned int cmd)
{
	static struct {
		int cmd;
		ioctl_fn fn;
	} _ioctls[] = {
		{DM_VERSION_CMD, NULL},	/* version is dealt with elsewhere */
		{DM_REMOVE_ALL_CMD, remove_all},
		{DM_LIST_DEVICES_CMD, list_devices},

		{DM_DEV_CREATE_CMD, dev_create},
		{DM_DEV_REMOVE_CMD, dev_remove},
		{DM_DEV_RENAME_CMD, dev_rename},
		{DM_DEV_SUSPEND_CMD, dev_suspend},
		{DM_DEV_STATUS_CMD, dev_status},
		{DM_DEV_WAIT_CMD, dev_wait},

		{DM_TABLE_LOAD_CMD, table_load},
		{DM_TABLE_CLEAR_CMD, table_clear},
		{DM_TABLE_DEPS_CMD, table_deps},
		{DM_TABLE_STATUS_CMD, table_status},

		{DM_LIST_VERSIONS_CMD, list_versions},

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Darrick J. Wong 已提交
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		{DM_TARGET_MSG_CMD, target_message},
		{DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
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1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511
	};

	return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
}

/*
 * As well as checking the version compatibility this always
 * copies the kernel interface version out.
 */
static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
{
	uint32_t version[3];
	int r = 0;

	if (copy_from_user(version, user->version, sizeof(version)))
		return -EFAULT;

	if ((DM_VERSION_MAJOR != version[0]) ||
	    (DM_VERSION_MINOR < version[1])) {
		DMWARN("ioctl interface mismatch: "
		       "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
		       DM_VERSION_MAJOR, DM_VERSION_MINOR,
		       DM_VERSION_PATCHLEVEL,
		       version[0], version[1], version[2], cmd);
		r = -EINVAL;
	}

	/*
	 * Fill in the kernel version.
	 */
	version[0] = DM_VERSION_MAJOR;
	version[1] = DM_VERSION_MINOR;
	version[2] = DM_VERSION_PATCHLEVEL;
	if (copy_to_user(user->version, version, sizeof(version)))
		return -EFAULT;

	return r;
}

static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
{
	struct dm_ioctl tmp, *dmi;
1512
	int secure_data;
L
Linus Torvalds 已提交
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M
Milan Broz 已提交
1514
	if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
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1515 1516
		return -EFAULT;

M
Milan Broz 已提交
1517
	if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
L
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1518 1519
		return -EINVAL;

1520 1521
	secure_data = tmp.flags & DM_SECURE_DATA_FLAG;

J
Jesper Juhl 已提交
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	dmi = vmalloc(tmp.data_size);
1523 1524 1525
	if (!dmi) {
		if (secure_data && clear_user(user, tmp.data_size))
			return -EFAULT;
L
Linus Torvalds 已提交
1526
		return -ENOMEM;
1527
	}
L
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1528

1529 1530
	if (copy_from_user(dmi, user, tmp.data_size))
		goto bad;
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1532 1533 1534 1535
	/* Wipe the user buffer so we do not return it to userspace */
	if (secure_data && clear_user(user, tmp.data_size))
		goto bad;

L
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1536 1537
	*param = dmi;
	return 0;
1538 1539

bad:
1540 1541
	if (secure_data)
		memset(dmi, 0, tmp.data_size);
1542 1543
	vfree(dmi);
	return -EFAULT;
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}

static int validate_params(uint cmd, struct dm_ioctl *param)
{
	/* Always clear this flag */
	param->flags &= ~DM_BUFFER_FULL_FLAG;
1550
	param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1551
	param->flags &= ~DM_SECURE_DATA_FLAG;
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	/* Ignores parameters */
	if (cmd == DM_REMOVE_ALL_CMD ||
	    cmd == DM_LIST_DEVICES_CMD ||
	    cmd == DM_LIST_VERSIONS_CMD)
		return 0;

	if ((cmd == DM_DEV_CREATE_CMD)) {
		if (!*param->name) {
			DMWARN("name not supplied when creating device");
			return -EINVAL;
		}
	} else if ((*param->uuid && *param->name)) {
		DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
		return -EINVAL;
	}

	/* Ensure strings are terminated */
	param->name[DM_NAME_LEN - 1] = '\0';
	param->uuid[DM_UUID_LEN - 1] = '\0';

	return 0;
}

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Alasdair G Kergon 已提交
1576
static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
L
Linus Torvalds 已提交
1577 1578
{
	int r = 0;
1579
	int wipe_buffer;
L
Linus Torvalds 已提交
1580
	unsigned int cmd;
A
Andrew Morton 已提交
1581
	struct dm_ioctl *uninitialized_var(param);
L
Linus Torvalds 已提交
1582
	ioctl_fn fn = NULL;
1583
	size_t input_param_size;
L
Linus Torvalds 已提交
1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624

	/* only root can play with this */
	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	if (_IOC_TYPE(command) != DM_IOCTL)
		return -ENOTTY;

	cmd = _IOC_NR(command);

	/*
	 * Check the interface version passed in.  This also
	 * writes out the kernel's interface version.
	 */
	r = check_version(cmd, user);
	if (r)
		return r;

	/*
	 * Nothing more to do for the version command.
	 */
	if (cmd == DM_VERSION_CMD)
		return 0;

	fn = lookup_ioctl(cmd);
	if (!fn) {
		DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
		return -ENOTTY;
	}

	/*
	 * Trying to avoid low memory issues when a device is
	 * suspended.
	 */
	current->flags |= PF_MEMALLOC;

	/*
	 * Copy the parameters into kernel space.
	 */
	r = copy_params(user, &param);

1625 1626 1627 1628
	current->flags &= ~PF_MEMALLOC;

	if (r)
		return r;
L
Linus Torvalds 已提交
1629

1630 1631 1632
	input_param_size = param->data_size;
	wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;

L
Linus Torvalds 已提交
1633 1634 1635 1636 1637
	r = validate_params(cmd, param);
	if (r)
		goto out;

	param->data_size = sizeof(*param);
1638
	r = fn(param, input_param_size);
L
Linus Torvalds 已提交
1639 1640 1641 1642 1643 1644 1645

	/*
	 * Copy the results back to userland.
	 */
	if (!r && copy_to_user(user, param, param->data_size))
		r = -EFAULT;

1646
out:
1647 1648 1649
	if (wipe_buffer)
		memset(param, 0, input_param_size);

1650
	vfree(param);
L
Linus Torvalds 已提交
1651 1652 1653
	return r;
}

A
Alasdair G Kergon 已提交
1654 1655 1656 1657 1658
static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
{
	return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
}

M
Milan Broz 已提交
1659 1660 1661 1662 1663 1664 1665 1666 1667
#ifdef CONFIG_COMPAT
static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
{
	return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
}
#else
#define dm_compat_ctl_ioctl NULL
#endif

1668
static const struct file_operations _ctl_fops = {
A
Arnd Bergmann 已提交
1669
	.open = nonseekable_open,
A
Alasdair G Kergon 已提交
1670
	.unlocked_ioctl	 = dm_ctl_ioctl,
M
Milan Broz 已提交
1671
	.compat_ioctl = dm_compat_ctl_ioctl,
L
Linus Torvalds 已提交
1672
	.owner	 = THIS_MODULE,
1673
	.llseek  = noop_llseek,
L
Linus Torvalds 已提交
1674 1675 1676
};

static struct miscdevice _dm_misc = {
P
Peter Rajnoha 已提交
1677
	.minor		= MAPPER_CTRL_MINOR,
L
Linus Torvalds 已提交
1678
	.name  		= DM_NAME,
P
Peter Rajnoha 已提交
1679
	.nodename	= DM_DIR "/" DM_CONTROL_NODE,
L
Linus Torvalds 已提交
1680 1681 1682
	.fops  		= &_ctl_fops
};

P
Peter Rajnoha 已提交
1683 1684 1685
MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);

L
Linus Torvalds 已提交
1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716
/*
 * Create misc character device and link to DM_DIR/control.
 */
int __init dm_interface_init(void)
{
	int r;

	r = dm_hash_init();
	if (r)
		return r;

	r = misc_register(&_dm_misc);
	if (r) {
		DMERR("misc_register failed for control device");
		dm_hash_exit();
		return r;
	}

	DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
	       DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
	       DM_DRIVER_EMAIL);
	return 0;
}

void dm_interface_exit(void)
{
	if (misc_deregister(&_dm_misc) < 0)
		DMERR("misc_deregister failed for control device");

	dm_hash_exit();
}
M
Mike Anderson 已提交
1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731

/**
 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
 * @md: Pointer to mapped_device
 * @name: Buffer (size DM_NAME_LEN) for name
 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
 */
int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
{
	int r = 0;
	struct hash_cell *hc;

	if (!md)
		return -ENXIO;

M
Mikulas Patocka 已提交
1732
	mutex_lock(&dm_hash_cells_mutex);
M
Mike Anderson 已提交
1733 1734 1735 1736 1737 1738
	hc = dm_get_mdptr(md);
	if (!hc || hc->md != md) {
		r = -ENXIO;
		goto out;
	}

1739 1740 1741 1742
	if (name)
		strcpy(name, hc->name);
	if (uuid)
		strcpy(uuid, hc->uuid ? : "");
M
Mike Anderson 已提交
1743 1744

out:
M
Mikulas Patocka 已提交
1745
	mutex_unlock(&dm_hash_cells_mutex);
M
Mike Anderson 已提交
1746 1747 1748

	return r;
}