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linux/drivers/md/dm-ioctl.c
Alasdair G Kergon c4cc66351a [PATCH] device-mapper: list_versions fix 
In some circumstances the LIST_VERSIONS output is truncated because the size
calculation forgets about a 'uint32_t' in each structure - but the inclusion
of the whole of ALIGN_MASK frequently compensates for the omission.

This is a quick workaround to use an upper bound.  (The code ought to be fixed
to supply the actual size.)

Running 'dmsetup targets' may demonstrate the problem: when I run it, the last
line comes out as 'erro' instead of 'error'.  Consequently, 'lvcreate --type
error' doesn't work.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-22 09:14:31 -08:00

1419 lines
29 KiB
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/*
* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
* Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved.
*
* 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/devfs_fs_kernel.h>
#include <linux/dm-ioctl.h>
#include <asm/uaccess.h>
#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];
static void dm_hash_remove_all(void);
/*
* Guards access to both hash tables.
*/
static DECLARE_RWSEM(_hash_lock);
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);
devfs_mk_dir(DM_DIR);
return 0;
}
static void dm_hash_exit(void)
{
dm_hash_remove_all();
devfs_remove(DM_DIR);
}
/*-----------------------------------------------------------------
* 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)
if (!strcmp(hc->name, str))
return hc;
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)
if (!strcmp(hc->uuid, str))
return hc;
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;
hc->name = kstrdup(name, GFP_KERNEL);
if (!hc->name) {
kfree(hc);
return NULL;
}
if (!uuid)
hc->uuid = NULL;
else {
hc->uuid = kstrdup(uuid, GFP_KERNEL);
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);
}
}
/*
* devfs stuff.
*/
static int register_with_devfs(struct hash_cell *hc)
{
struct gendisk *disk = dm_disk(hc->md);
devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
DM_DIR "/%s", hc->name);
return 0;
}
static int unregister_with_devfs(struct hash_cell *hc)
{
devfs_remove(DM_DIR"/%s", hc->name);
return 0;
}
/*
* 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)
{
struct hash_cell *cell;
/*
* 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);
if (__get_name_cell(name))
goto bad;
list_add(&cell->name_list, _name_buckets + hash_str(name));
if (uuid) {
if (__get_uuid_cell(uuid)) {
list_del(&cell->name_list);
goto bad;
}
list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
}
register_with_devfs(cell);
dm_get(md);
dm_set_mdptr(md, cell);
up_write(&_hash_lock);
return 0;
bad:
up_write(&_hash_lock);
free_cell(cell);
return -EBUSY;
}
static void __hash_remove(struct hash_cell *hc)
{
struct dm_table *table;
/* remove from the dev hash */
list_del(&hc->uuid_list);
list_del(&hc->name_list);
unregister_with_devfs(hc);
dm_set_mdptr(hc->md, NULL);
table = dm_get_table(hc->md);
if (table) {
dm_table_event(table);
dm_table_put(table);
}
dm_put(hc->md);
if (hc->new_map)
dm_table_put(hc->new_map);
free_cell(hc);
}
static void dm_hash_remove_all(void)
{
int i;
struct hash_cell *hc;
struct list_head *tmp, *n;
down_write(&_hash_lock);
for (i = 0; i < NUM_BUCKETS; i++) {
list_for_each_safe (tmp, n, _name_buckets + i) {
hc = list_entry(tmp, struct hash_cell, name_list);
__hash_remove(hc);
}
}
up_write(&_hash_lock);
}
static int dm_hash_rename(const char *old, const char *new)
{
char *new_name, *old_name;
struct hash_cell *hc;
/*
* duplicate new.
*/
new_name = kstrdup(new, GFP_KERNEL);
if (!new_name)
return -ENOMEM;
down_write(&_hash_lock);
/*
* Is new free ?
*/
hc = __get_name_cell(new);
if (hc) {
DMWARN("asked to rename to an already existing name %s -> %s",
old, new);
up_write(&_hash_lock);
kfree(new_name);
return -EBUSY;
}
/*
* Is there such a device as 'old' ?
*/
hc = __get_name_cell(old);
if (!hc) {
DMWARN("asked to rename a non existent device %s -> %s",
old, new);
up_write(&_hash_lock);
kfree(new_name);
return -ENXIO;
}
/*
* rename and move the name cell.
*/
unregister_with_devfs(hc);
list_del(&hc->name_list);
old_name = hc->name;
hc->name = new_name;
list_add(&hc->name_list, _name_buckets + hash_str(new_name));
/* rename the device node in devfs */
register_with_devfs(hc);
up_write(&_hash_lock);
kfree(old_name);
return 0;
}
/*-----------------------------------------------------------------
* 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)
{
dm_hash_remove_all();
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);
nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
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;
*needed += sizeof(struct dm_target_versions);
*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;
}
/*
* Fills in a dm_ioctl structure, ready for sending back to
* userland.
*/
static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
{
struct gendisk *disk = dm_disk(md);
struct dm_table *table;
struct block_device *bdev;
param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
DM_ACTIVE_PRESENT_FLAG);
if (dm_suspended(md))
param->flags |= DM_SUSPEND_FLAG;
param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
if (!(param->flags & DM_SKIP_BDGET_FLAG)) {
bdev = bdget_disk(disk, 0);
if (!bdev)
return -ENXIO;
/*
* 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 = bdev->bd_openers;
bdput(bdev);
} else
param->open_count = -1;
if (disk->policy)
param->flags |= DM_READONLY_FLAG;
param->event_nr = dm_get_event_nr(md);
table = dm_get_table(md);
if (table) {
param->flags |= DM_ACTIVE_PRESENT_FLAG;
param->target_count = dm_table_get_num_targets(table);
dm_table_put(table);
} else
param->target_count = 0;
return 0;
}
static int dev_create(struct dm_ioctl *param, size_t param_size)
{
int r;
struct mapped_device *md;
r = check_name(param->name);
if (r)
return r;
if (param->flags & DM_PERSISTENT_DEV_FLAG)
r = dm_create_with_minor(MINOR(huge_decode_dev(param->dev)), &md);
else
r = dm_create(&md);
if (r)
return r;
r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
if (r) {
dm_put(md);
return r;
}
param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
r = __dev_status(md, param);
dm_put(md);
return r;
}
/*
* Always use UUID for lookups if it's present, otherwise use name or dev.
*/
static inline struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
{
if (*param->uuid)
return __get_uuid_cell(param->uuid);
else if (*param->name)
return __get_name_cell(param->name);
else
return dm_get_mdptr(huge_decode_dev(param->dev));
}
static inline struct mapped_device *find_device(struct dm_ioctl *param)
{
struct hash_cell *hc;
struct mapped_device *md = NULL;
down_read(&_hash_lock);
hc = __find_device_hash_cell(param);
if (hc) {
md = hc->md;
dm_get(md);
/*
* Sneakily write in both the name and the uuid
* while we have the cell.
*/
strncpy(param->name, hc->name, sizeof(param->name));
if (hc->uuid)
strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1);
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;
down_write(&_hash_lock);
hc = __find_device_hash_cell(param);
if (!hc) {
DMWARN("device doesn't appear to be in the dev hash table.");
up_write(&_hash_lock);
return -ENXIO;
}
__hash_remove(hc);
up_write(&_hash_lock);
param->data_size = 0;
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;
char *new_name = (char *) param + param->data_start;
if (new_name < (char *) (param + 1) ||
invalid_str(new_name, (void *) param + param_size)) {
DMWARN("Invalid new logical volume name supplied.");
return -EINVAL;
}
r = check_name(new_name);
if (r)
return r;
param->data_size = 0;
return dm_hash_rename(param->name, new_name);
}
static int do_suspend(struct dm_ioctl *param)
{
int r = 0;
struct mapped_device *md;
md = find_device(param);
if (!md)
return -ENXIO;
if (!dm_suspended(md))
r = dm_suspend(md);
if (!r)
r = __dev_status(md, param);
dm_put(md);
return r;
}
static int do_resume(struct dm_ioctl *param)
{
int r = 0;
struct hash_cell *hc;
struct mapped_device *md;
struct dm_table *new_map;
down_write(&_hash_lock);
hc = __find_device_hash_cell(param);
if (!hc) {
DMWARN("device doesn't appear to be in the dev hash table.");
up_write(&_hash_lock);
return -ENXIO;
}
md = hc->md;
dm_get(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 */
if (!dm_suspended(md))
dm_suspend(md);
r = dm_swap_table(md, new_map);
if (r) {
dm_put(md);
dm_table_put(new_map);
return r;
}
if (dm_table_get_mode(new_map) & FMODE_WRITE)
set_disk_ro(dm_disk(md), 0);
else
set_disk_ro(dm_disk(md), 1);
dm_table_put(new_map);
}
if (dm_suspended(md))
r = dm_resume(md);
if (!r)
r = __dev_status(md, param);
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)
{
int r;
struct mapped_device *md;
md = find_device(param);
if (!md)
return -ENXIO;
r = __dev_status(md, param);
dm_put(md);
return r;
}
/*
* 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)
{
int r;
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.
*/
r = __dev_status(md, param);
if (r)
goto out;
table = dm_get_table(md);
if (table) {
retrieve_status(table, param, param_size);
dm_table_put(table);
}
out:
dm_put(md);
return r;
}
static inline int get_mode(struct dm_ioctl *param)
{
int mode = FMODE_READ | FMODE_WRITE;
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;
r = dm_table_create(&t, get_mode(param), param->target_count);
if (r)
return r;
r = populate_table(t, param, param_size);
if (r) {
dm_table_put(t);
return r;
}
down_write(&_hash_lock);
hc = __find_device_hash_cell(param);
if (!hc) {
DMWARN("device doesn't appear to be in the dev hash table.");
up_write(&_hash_lock);
dm_table_put(t);
return -ENXIO;
}
if (hc->new_map)
dm_table_put(hc->new_map);
hc->new_map = t;
param->flags |= DM_INACTIVE_PRESENT_FLAG;
r = __dev_status(hc->md, param);
up_write(&_hash_lock);
return r;
}
static int table_clear(struct dm_ioctl *param, size_t param_size)
{
int r;
struct hash_cell *hc;
down_write(&_hash_lock);
hc = __find_device_hash_cell(param);
if (!hc) {
DMWARN("device doesn't appear to be in the dev hash table.");
up_write(&_hash_lock);
return -ENXIO;
}
if (hc->new_map) {
dm_table_put(hc->new_map);
hc->new_map = NULL;
}
param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
r = __dev_status(hc->md, param);
up_write(&_hash_lock);
return r;
}
/*
* 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;
struct dm_dev *dd;
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)
deps->dev[count++] = huge_encode_dev(dd->bdev->bd_dev);
param->data_size = param->data_start + needed;
}
static int table_deps(struct dm_ioctl *param, size_t param_size)
{
int r = 0;
struct mapped_device *md;
struct dm_table *table;
md = find_device(param);
if (!md)
return -ENXIO;
r = __dev_status(md, param);
if (r)
goto out;
table = dm_get_table(md);
if (table) {
retrieve_deps(table, param, param_size);
dm_table_put(table);
}
out:
dm_put(md);
return r;
}
/*
* 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)
{
int r;
struct mapped_device *md;
struct dm_table *table;
md = find_device(param);
if (!md)
return -ENXIO;
r = __dev_status(md, param);
if (r)
goto out;
table = dm_get_table(md);
if (table) {
retrieve_status(table, param, param_size);
dm_table_put(table);
}
out:
dm_put(md);
return r;
}
/*
* 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;
r = __dev_status(md, param);
if (r)
goto out;
if (tmsg < (struct dm_target_msg *) (param + 1) ||
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;
}
table = dm_get_table(md);
if (!table)
goto out_argv;
if (tmsg->sector >= dm_table_get_size(table)) {
DMWARN("Target message sector outside device.");
r = -EINVAL;
goto out_table;
}
ti = dm_table_find_target(table, tmsg->sector);
if (ti->type->message)
r = ti->type->message(ti, argc, argv);
else {
DMWARN("Target type does not support messages");
r = -EINVAL;
}
out_table:
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},
{DM_TARGET_MSG_CMD, target_message}
};
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 void free_params(struct dm_ioctl *param)
{
vfree(param);
}
static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
{
struct dm_ioctl tmp, *dmi;
if (copy_from_user(&tmp, user, sizeof(tmp)))
return -EFAULT;
if (tmp.data_size < sizeof(tmp))
return -EINVAL;
dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
if (!dmi)
return -ENOMEM;
if (copy_from_user(dmi, user, tmp.data_size)) {
vfree(dmi);
return -EFAULT;
}
*param = dmi;
return 0;
}
static int validate_params(uint cmd, struct dm_ioctl *param)
{
/* Always clear this flag */
param->flags &= ~DM_BUFFER_FULL_FLAG;
/* 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;
}
static int ctl_ioctl(struct inode *inode, struct file *file,
uint command, ulong u)
{
int r = 0;
unsigned int cmd;
struct dm_ioctl *param;
struct dm_ioctl __user *user = (struct dm_ioctl __user *) u;
ioctl_fn fn = NULL;
size_t param_size;
/* 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);
if (r) {
current->flags &= ~PF_MEMALLOC;
return r;
}
/*
* FIXME: eventually we will remove the PF_MEMALLOC flag
* here. However the tools still do nasty things like
* 'load' while a device is suspended.
*/
r = validate_params(cmd, param);
if (r)
goto out;
param_size = param->data_size;
param->data_size = sizeof(*param);
r = fn(param, param_size);
/*
* Copy the results back to userland.
*/
if (!r && copy_to_user(user, param, param->data_size))
r = -EFAULT;
out:
free_params(param);
current->flags &= ~PF_MEMALLOC;
return r;
}
static struct file_operations _ctl_fops = {
.ioctl = ctl_ioctl,
.owner = THIS_MODULE,
};
static struct miscdevice _dm_misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DM_NAME,
.devfs_name = "mapper/control",
.fops = &_ctl_fops
};
/*
* 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();
}
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