2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
5 * This file is released under the GPL.
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/miscdevice.h>
13 #include <linux/init.h>
14 #include <linux/wait.h>
15 #include <linux/slab.h>
16 #include <linux/devfs_fs_kernel.h>
17 #include <linux/dm-ioctl.h>
19 #include <asm/uaccess.h>
21 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
23 /*-----------------------------------------------------------------
24 * The ioctl interface needs to be able to look up devices by
26 *---------------------------------------------------------------*/
28 struct list_head name_list;
29 struct list_head uuid_list;
33 struct mapped_device *md;
34 struct dm_table *new_map;
39 struct dm_target_versions *vers, *old_vers;
45 #define NUM_BUCKETS 64
46 #define MASK_BUCKETS (NUM_BUCKETS - 1)
47 static struct list_head _name_buckets[NUM_BUCKETS];
48 static struct list_head _uuid_buckets[NUM_BUCKETS];
50 static void dm_hash_remove_all(void);
53 * Guards access to both hash tables.
55 static DECLARE_RWSEM(_hash_lock);
57 static void init_buckets(struct list_head *buckets)
61 for (i = 0; i < NUM_BUCKETS; i++)
62 INIT_LIST_HEAD(buckets + i);
65 static int dm_hash_init(void)
67 init_buckets(_name_buckets);
68 init_buckets(_uuid_buckets);
73 static void dm_hash_exit(void)
79 /*-----------------------------------------------------------------
81 * We're not really concerned with the str hash function being
82 * fast since it's only used by the ioctl interface.
83 *---------------------------------------------------------------*/
84 static unsigned int hash_str(const char *str)
86 const unsigned int hash_mult = 2654435387U;
90 h = (h + (unsigned int) *str++) * hash_mult;
92 return h & MASK_BUCKETS;
95 /*-----------------------------------------------------------------
96 * Code for looking up a device by name
97 *---------------------------------------------------------------*/
98 static struct hash_cell *__get_name_cell(const char *str)
100 struct hash_cell *hc;
101 unsigned int h = hash_str(str);
103 list_for_each_entry (hc, _name_buckets + h, name_list)
104 if (!strcmp(hc->name, str))
110 static struct hash_cell *__get_uuid_cell(const char *str)
112 struct hash_cell *hc;
113 unsigned int h = hash_str(str);
115 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
116 if (!strcmp(hc->uuid, str))
122 /*-----------------------------------------------------------------
123 * Inserting, removing and renaming a device.
124 *---------------------------------------------------------------*/
125 static inline char *kstrdup(const char *str)
127 char *r = kmalloc(strlen(str) + 1, GFP_KERNEL);
133 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
134 struct mapped_device *md)
136 struct hash_cell *hc;
138 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
142 hc->name = kstrdup(name);
152 hc->uuid = kstrdup(uuid);
160 INIT_LIST_HEAD(&hc->name_list);
161 INIT_LIST_HEAD(&hc->uuid_list);
167 static void free_cell(struct hash_cell *hc)
179 static int register_with_devfs(struct hash_cell *hc)
181 struct gendisk *disk = dm_disk(hc->md);
183 devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
184 S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
185 DM_DIR "/%s", hc->name);
189 static int unregister_with_devfs(struct hash_cell *hc)
191 devfs_remove(DM_DIR"/%s", hc->name);
196 * The kdev_t and uuid of a device can never change once it is
197 * initially inserted.
199 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
201 struct hash_cell *cell;
204 * Allocate the new cells.
206 cell = alloc_cell(name, uuid, md);
211 * Insert the cell into both hash tables.
213 down_write(&_hash_lock);
214 if (__get_name_cell(name))
217 list_add(&cell->name_list, _name_buckets + hash_str(name));
220 if (__get_uuid_cell(uuid)) {
221 list_del(&cell->name_list);
224 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
226 register_with_devfs(cell);
228 dm_set_mdptr(md, cell);
229 up_write(&_hash_lock);
234 up_write(&_hash_lock);
239 static void __hash_remove(struct hash_cell *hc)
241 /* remove from the dev hash */
242 list_del(&hc->uuid_list);
243 list_del(&hc->name_list);
244 unregister_with_devfs(hc);
245 dm_set_mdptr(hc->md, NULL);
248 dm_table_put(hc->new_map);
252 static void dm_hash_remove_all(void)
255 struct hash_cell *hc;
256 struct list_head *tmp, *n;
258 down_write(&_hash_lock);
259 for (i = 0; i < NUM_BUCKETS; i++) {
260 list_for_each_safe (tmp, n, _name_buckets + i) {
261 hc = list_entry(tmp, struct hash_cell, name_list);
265 up_write(&_hash_lock);
268 static int dm_hash_rename(const char *old, const char *new)
270 char *new_name, *old_name;
271 struct hash_cell *hc;
276 new_name = kstrdup(new);
280 down_write(&_hash_lock);
285 hc = __get_name_cell(new);
287 DMWARN("asked to rename to an already existing name %s -> %s",
289 up_write(&_hash_lock);
295 * Is there such a device as 'old' ?
297 hc = __get_name_cell(old);
299 DMWARN("asked to rename a non existent device %s -> %s",
301 up_write(&_hash_lock);
307 * rename and move the name cell.
309 unregister_with_devfs(hc);
311 list_del(&hc->name_list);
314 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
316 /* rename the device node in devfs */
317 register_with_devfs(hc);
319 up_write(&_hash_lock);
324 /*-----------------------------------------------------------------
325 * Implementation of the ioctl commands
326 *---------------------------------------------------------------*/
328 * All the ioctl commands get dispatched to functions with this
331 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
333 static int remove_all(struct dm_ioctl *param, size_t param_size)
335 dm_hash_remove_all();
336 param->data_size = 0;
341 * Round up the ptr to an 8-byte boundary.
344 static inline void *align_ptr(void *ptr)
346 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
350 * Retrieves the data payload buffer from an already allocated
353 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
356 param->data_start = align_ptr(param + 1) - (void *) param;
358 if (param->data_start < param_size)
359 *len = param_size - param->data_start;
363 return ((void *) param) + param->data_start;
366 static int list_devices(struct dm_ioctl *param, size_t param_size)
369 struct hash_cell *hc;
370 size_t len, needed = 0;
371 struct gendisk *disk;
372 struct dm_name_list *nl, *old_nl = NULL;
374 down_write(&_hash_lock);
377 * Loop through all the devices working out how much
380 for (i = 0; i < NUM_BUCKETS; i++) {
381 list_for_each_entry (hc, _name_buckets + i, name_list) {
382 needed += sizeof(struct dm_name_list);
383 needed += strlen(hc->name) + 1;
384 needed += ALIGN_MASK;
389 * Grab our output buffer.
391 nl = get_result_buffer(param, param_size, &len);
393 param->flags |= DM_BUFFER_FULL_FLAG;
396 param->data_size = param->data_start + needed;
398 nl->dev = 0; /* Flags no data */
401 * Now loop through filling out the names.
403 for (i = 0; i < NUM_BUCKETS; i++) {
404 list_for_each_entry (hc, _name_buckets + i, name_list) {
406 old_nl->next = (uint32_t) ((void *) nl -
408 disk = dm_disk(hc->md);
409 nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
411 strcpy(nl->name, hc->name);
414 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
419 up_write(&_hash_lock);
423 static void list_version_get_needed(struct target_type *tt, void *needed_param)
425 size_t *needed = needed_param;
427 *needed += strlen(tt->name);
428 *needed += sizeof(tt->version);
429 *needed += ALIGN_MASK;
432 static void list_version_get_info(struct target_type *tt, void *param)
434 struct vers_iter *info = param;
436 /* Check space - it might have changed since the first iteration */
437 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
440 info->flags = DM_BUFFER_FULL_FLAG;
445 info->old_vers->next = (uint32_t) ((void *)info->vers -
446 (void *)info->old_vers);
447 info->vers->version[0] = tt->version[0];
448 info->vers->version[1] = tt->version[1];
449 info->vers->version[2] = tt->version[2];
450 info->vers->next = 0;
451 strcpy(info->vers->name, tt->name);
453 info->old_vers = info->vers;
454 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
457 static int list_versions(struct dm_ioctl *param, size_t param_size)
459 size_t len, needed = 0;
460 struct dm_target_versions *vers;
461 struct vers_iter iter_info;
464 * Loop through all the devices working out how much
467 dm_target_iterate(list_version_get_needed, &needed);
470 * Grab our output buffer.
472 vers = get_result_buffer(param, param_size, &len);
474 param->flags |= DM_BUFFER_FULL_FLAG;
477 param->data_size = param->data_start + needed;
479 iter_info.param_size = param_size;
480 iter_info.old_vers = NULL;
481 iter_info.vers = vers;
483 iter_info.end = (char *)vers+len;
486 * Now loop through filling out the names & versions.
488 dm_target_iterate(list_version_get_info, &iter_info);
489 param->flags |= iter_info.flags;
497 static int check_name(const char *name)
499 if (strchr(name, '/')) {
500 DMWARN("invalid device name");
508 * Fills in a dm_ioctl structure, ready for sending back to
511 static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
513 struct gendisk *disk = dm_disk(md);
514 struct dm_table *table;
515 struct block_device *bdev;
517 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
518 DM_ACTIVE_PRESENT_FLAG);
520 if (dm_suspended(md))
521 param->flags |= DM_SUSPEND_FLAG;
523 bdev = bdget_disk(disk, 0);
527 param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
530 * Yes, this will be out of date by the time it gets back
531 * to userland, but it is still very useful ofr
534 param->open_count = bdev->bd_openers;
538 param->flags |= DM_READONLY_FLAG;
540 param->event_nr = dm_get_event_nr(md);
542 table = dm_get_table(md);
544 param->flags |= DM_ACTIVE_PRESENT_FLAG;
545 param->target_count = dm_table_get_num_targets(table);
548 param->target_count = 0;
553 static int dev_create(struct dm_ioctl *param, size_t param_size)
556 struct mapped_device *md;
558 r = check_name(param->name);
562 if (param->flags & DM_PERSISTENT_DEV_FLAG)
563 r = dm_create_with_minor(MINOR(huge_decode_dev(param->dev)), &md);
570 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
576 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
578 r = __dev_status(md, param);
585 * Always use UUID for lookups if it's present, otherwise use name or dev.
587 static inline struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
590 return __get_uuid_cell(param->uuid);
591 else if (*param->name)
592 return __get_name_cell(param->name);
594 return dm_get_mdptr(huge_decode_dev(param->dev));
597 static inline struct mapped_device *find_device(struct dm_ioctl *param)
599 struct hash_cell *hc;
600 struct mapped_device *md = NULL;
602 down_read(&_hash_lock);
603 hc = __find_device_hash_cell(param);
609 * Sneakily write in both the name and the uuid
610 * while we have the cell.
612 strncpy(param->name, hc->name, sizeof(param->name));
614 strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1);
616 param->uuid[0] = '\0';
619 param->flags |= DM_INACTIVE_PRESENT_FLAG;
621 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
623 up_read(&_hash_lock);
628 static int dev_remove(struct dm_ioctl *param, size_t param_size)
630 struct hash_cell *hc;
632 down_write(&_hash_lock);
633 hc = __find_device_hash_cell(param);
636 DMWARN("device doesn't appear to be in the dev hash table.");
637 up_write(&_hash_lock);
642 up_write(&_hash_lock);
643 param->data_size = 0;
648 * Check a string doesn't overrun the chunk of
649 * memory we copied from userland.
651 static int invalid_str(char *str, void *end)
653 while ((void *) str < end)
660 static int dev_rename(struct dm_ioctl *param, size_t param_size)
663 char *new_name = (char *) param + param->data_start;
665 if (new_name < (char *) (param + 1) ||
666 invalid_str(new_name, (void *) param + param_size)) {
667 DMWARN("Invalid new logical volume name supplied.");
671 r = check_name(new_name);
675 param->data_size = 0;
676 return dm_hash_rename(param->name, new_name);
679 static int do_suspend(struct dm_ioctl *param)
682 struct mapped_device *md;
684 md = find_device(param);
688 if (!dm_suspended(md))
692 r = __dev_status(md, param);
698 static int do_resume(struct dm_ioctl *param)
701 struct hash_cell *hc;
702 struct mapped_device *md;
703 struct dm_table *new_map;
705 down_write(&_hash_lock);
707 hc = __find_device_hash_cell(param);
709 DMWARN("device doesn't appear to be in the dev hash table.");
710 up_write(&_hash_lock);
717 new_map = hc->new_map;
719 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
721 up_write(&_hash_lock);
723 /* Do we need to load a new map ? */
725 /* Suspend if it isn't already suspended */
726 if (!dm_suspended(md))
729 r = dm_swap_table(md, new_map);
732 dm_table_put(new_map);
736 if (dm_table_get_mode(new_map) & FMODE_WRITE)
737 set_disk_ro(dm_disk(md), 0);
739 set_disk_ro(dm_disk(md), 1);
741 dm_table_put(new_map);
744 if (dm_suspended(md))
748 r = __dev_status(md, param);
755 * Set or unset the suspension state of a device.
756 * If the device already is in the requested state we just return its status.
758 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
760 if (param->flags & DM_SUSPEND_FLAG)
761 return do_suspend(param);
763 return do_resume(param);
767 * Copies device info back to user space, used by
768 * the create and info ioctls.
770 static int dev_status(struct dm_ioctl *param, size_t param_size)
773 struct mapped_device *md;
775 md = find_device(param);
779 r = __dev_status(md, param);
785 * Build up the status struct for each target
787 static void retrieve_status(struct dm_table *table,
788 struct dm_ioctl *param, size_t param_size)
790 unsigned int i, num_targets;
791 struct dm_target_spec *spec;
792 char *outbuf, *outptr;
794 size_t remaining, len, used = 0;
796 outptr = outbuf = get_result_buffer(param, param_size, &len);
798 if (param->flags & DM_STATUS_TABLE_FLAG)
799 type = STATUSTYPE_TABLE;
801 type = STATUSTYPE_INFO;
803 /* Get all the target info */
804 num_targets = dm_table_get_num_targets(table);
805 for (i = 0; i < num_targets; i++) {
806 struct dm_target *ti = dm_table_get_target(table, i);
808 remaining = len - (outptr - outbuf);
809 if (remaining <= sizeof(struct dm_target_spec)) {
810 param->flags |= DM_BUFFER_FULL_FLAG;
814 spec = (struct dm_target_spec *) outptr;
817 spec->sector_start = ti->begin;
818 spec->length = ti->len;
819 strncpy(spec->target_type, ti->type->name,
820 sizeof(spec->target_type));
822 outptr += sizeof(struct dm_target_spec);
823 remaining = len - (outptr - outbuf);
824 if (remaining <= 0) {
825 param->flags |= DM_BUFFER_FULL_FLAG;
829 /* Get the status/table string from the target driver */
830 if (ti->type->status) {
831 if (ti->type->status(ti, type, outptr, remaining)) {
832 param->flags |= DM_BUFFER_FULL_FLAG;
838 outptr += strlen(outptr) + 1;
839 used = param->data_start + (outptr - outbuf);
841 outptr = align_ptr(outptr);
842 spec->next = outptr - outbuf;
846 param->data_size = used;
848 param->target_count = num_targets;
852 * Wait for a device to report an event
854 static int dev_wait(struct dm_ioctl *param, size_t param_size)
857 struct mapped_device *md;
858 struct dm_table *table;
860 md = find_device(param);
865 * Wait for a notification event
867 if (dm_wait_event(md, param->event_nr)) {
873 * The userland program is going to want to know what
874 * changed to trigger the event, so we may as well tell
875 * him and save an ioctl.
877 r = __dev_status(md, param);
881 table = dm_get_table(md);
883 retrieve_status(table, param, param_size);
892 static inline int get_mode(struct dm_ioctl *param)
894 int mode = FMODE_READ | FMODE_WRITE;
896 if (param->flags & DM_READONLY_FLAG)
902 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
903 struct dm_target_spec **spec, char **target_params)
905 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
906 *target_params = (char *) (*spec + 1);
908 if (*spec < (last + 1))
911 return invalid_str(*target_params, end);
914 static int populate_table(struct dm_table *table,
915 struct dm_ioctl *param, size_t param_size)
919 struct dm_target_spec *spec = (struct dm_target_spec *) param;
920 uint32_t next = param->data_start;
921 void *end = (void *) param + param_size;
924 if (!param->target_count) {
925 DMWARN("populate_table: no targets specified");
929 for (i = 0; i < param->target_count; i++) {
931 r = next_target(spec, next, end, &spec, &target_params);
933 DMWARN("unable to find target");
937 r = dm_table_add_target(table, spec->target_type,
938 (sector_t) spec->sector_start,
939 (sector_t) spec->length,
942 DMWARN("error adding target to table");
949 return dm_table_complete(table);
952 static int table_load(struct dm_ioctl *param, size_t param_size)
955 struct hash_cell *hc;
958 r = dm_table_create(&t, get_mode(param), param->target_count);
962 r = populate_table(t, param, param_size);
968 down_write(&_hash_lock);
969 hc = __find_device_hash_cell(param);
971 DMWARN("device doesn't appear to be in the dev hash table.");
972 up_write(&_hash_lock);
977 dm_table_put(hc->new_map);
979 param->flags |= DM_INACTIVE_PRESENT_FLAG;
981 r = __dev_status(hc->md, param);
982 up_write(&_hash_lock);
986 static int table_clear(struct dm_ioctl *param, size_t param_size)
989 struct hash_cell *hc;
991 down_write(&_hash_lock);
993 hc = __find_device_hash_cell(param);
995 DMWARN("device doesn't appear to be in the dev hash table.");
996 up_write(&_hash_lock);
1001 dm_table_put(hc->new_map);
1005 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1007 r = __dev_status(hc->md, param);
1008 up_write(&_hash_lock);
1013 * Retrieves a list of devices used by a particular dm device.
1015 static void retrieve_deps(struct dm_table *table,
1016 struct dm_ioctl *param, size_t param_size)
1018 unsigned int count = 0;
1019 struct list_head *tmp;
1022 struct dm_target_deps *deps;
1024 deps = get_result_buffer(param, param_size, &len);
1027 * Count the devices.
1029 list_for_each (tmp, dm_table_get_devices(table))
1033 * Check we have enough space.
1035 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1037 param->flags |= DM_BUFFER_FULL_FLAG;
1042 * Fill in the devices.
1044 deps->count = count;
1046 list_for_each_entry (dd, dm_table_get_devices(table), list)
1047 deps->dev[count++] = huge_encode_dev(dd->bdev->bd_dev);
1049 param->data_size = param->data_start + needed;
1052 static int table_deps(struct dm_ioctl *param, size_t param_size)
1055 struct mapped_device *md;
1056 struct dm_table *table;
1058 md = find_device(param);
1062 r = __dev_status(md, param);
1066 table = dm_get_table(md);
1068 retrieve_deps(table, param, param_size);
1069 dm_table_put(table);
1078 * Return the status of a device as a text string for each
1081 static int table_status(struct dm_ioctl *param, size_t param_size)
1084 struct mapped_device *md;
1085 struct dm_table *table;
1087 md = find_device(param);
1091 r = __dev_status(md, param);
1095 table = dm_get_table(md);
1097 retrieve_status(table, param, param_size);
1098 dm_table_put(table);
1107 * Pass a message to the target that's at the supplied device offset.
1109 static int target_message(struct dm_ioctl *param, size_t param_size)
1113 struct mapped_device *md;
1114 struct dm_table *table;
1115 struct dm_target *ti;
1116 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1118 md = find_device(param);
1122 r = __dev_status(md, param);
1126 if (tmsg < (struct dm_target_msg *) (param + 1) ||
1127 invalid_str(tmsg->message, (void *) param + param_size)) {
1128 DMWARN("Invalid target message parameters.");
1133 r = dm_split_args(&argc, &argv, tmsg->message);
1135 DMWARN("Failed to split target message parameters");
1139 table = dm_get_table(md);
1143 if (tmsg->sector >= dm_table_get_size(table)) {
1144 DMWARN("Target message sector outside device.");
1149 ti = dm_table_find_target(table, tmsg->sector);
1150 if (ti->type->message)
1151 r = ti->type->message(ti, argc, argv);
1153 DMWARN("Target type does not support messages");
1158 dm_table_put(table);
1162 param->data_size = 0;
1167 /*-----------------------------------------------------------------
1168 * Implementation of open/close/ioctl on the special char
1170 *---------------------------------------------------------------*/
1171 static ioctl_fn lookup_ioctl(unsigned int cmd)
1177 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1178 {DM_REMOVE_ALL_CMD, remove_all},
1179 {DM_LIST_DEVICES_CMD, list_devices},
1181 {DM_DEV_CREATE_CMD, dev_create},
1182 {DM_DEV_REMOVE_CMD, dev_remove},
1183 {DM_DEV_RENAME_CMD, dev_rename},
1184 {DM_DEV_SUSPEND_CMD, dev_suspend},
1185 {DM_DEV_STATUS_CMD, dev_status},
1186 {DM_DEV_WAIT_CMD, dev_wait},
1188 {DM_TABLE_LOAD_CMD, table_load},
1189 {DM_TABLE_CLEAR_CMD, table_clear},
1190 {DM_TABLE_DEPS_CMD, table_deps},
1191 {DM_TABLE_STATUS_CMD, table_status},
1193 {DM_LIST_VERSIONS_CMD, list_versions},
1195 {DM_TARGET_MSG_CMD, target_message}
1198 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1202 * As well as checking the version compatibility this always
1203 * copies the kernel interface version out.
1205 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1207 uint32_t version[3];
1210 if (copy_from_user(version, user->version, sizeof(version)))
1213 if ((DM_VERSION_MAJOR != version[0]) ||
1214 (DM_VERSION_MINOR < version[1])) {
1215 DMWARN("ioctl interface mismatch: "
1216 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1217 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1218 DM_VERSION_PATCHLEVEL,
1219 version[0], version[1], version[2], cmd);
1224 * Fill in the kernel version.
1226 version[0] = DM_VERSION_MAJOR;
1227 version[1] = DM_VERSION_MINOR;
1228 version[2] = DM_VERSION_PATCHLEVEL;
1229 if (copy_to_user(user->version, version, sizeof(version)))
1235 static void free_params(struct dm_ioctl *param)
1240 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1242 struct dm_ioctl tmp, *dmi;
1244 if (copy_from_user(&tmp, user, sizeof(tmp)))
1247 if (tmp.data_size < sizeof(tmp))
1250 dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
1254 if (copy_from_user(dmi, user, tmp.data_size)) {
1263 static int validate_params(uint cmd, struct dm_ioctl *param)
1265 /* Always clear this flag */
1266 param->flags &= ~DM_BUFFER_FULL_FLAG;
1268 /* Ignores parameters */
1269 if (cmd == DM_REMOVE_ALL_CMD ||
1270 cmd == DM_LIST_DEVICES_CMD ||
1271 cmd == DM_LIST_VERSIONS_CMD)
1274 if ((cmd == DM_DEV_CREATE_CMD)) {
1275 if (!*param->name) {
1276 DMWARN("name not supplied when creating device");
1279 } else if ((*param->uuid && *param->name)) {
1280 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1284 /* Ensure strings are terminated */
1285 param->name[DM_NAME_LEN - 1] = '\0';
1286 param->uuid[DM_UUID_LEN - 1] = '\0';
1291 static int ctl_ioctl(struct inode *inode, struct file *file,
1292 uint command, ulong u)
1296 struct dm_ioctl *param;
1297 struct dm_ioctl __user *user = (struct dm_ioctl __user *) u;
1301 /* only root can play with this */
1302 if (!capable(CAP_SYS_ADMIN))
1305 if (_IOC_TYPE(command) != DM_IOCTL)
1308 cmd = _IOC_NR(command);
1311 * Check the interface version passed in. This also
1312 * writes out the kernel's interface version.
1314 r = check_version(cmd, user);
1319 * Nothing more to do for the version command.
1321 if (cmd == DM_VERSION_CMD)
1324 fn = lookup_ioctl(cmd);
1326 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1331 * Trying to avoid low memory issues when a device is
1334 current->flags |= PF_MEMALLOC;
1337 * Copy the parameters into kernel space.
1339 r = copy_params(user, ¶m);
1341 current->flags &= ~PF_MEMALLOC;
1346 * FIXME: eventually we will remove the PF_MEMALLOC flag
1347 * here. However the tools still do nasty things like
1348 * 'load' while a device is suspended.
1351 r = validate_params(cmd, param);
1355 param_size = param->data_size;
1356 param->data_size = sizeof(*param);
1357 r = fn(param, param_size);
1360 * Copy the results back to userland.
1362 if (!r && copy_to_user(user, param, param->data_size))
1367 current->flags &= ~PF_MEMALLOC;
1371 static struct file_operations _ctl_fops = {
1373 .owner = THIS_MODULE,
1376 static struct miscdevice _dm_misc = {
1377 .minor = MISC_DYNAMIC_MINOR,
1379 .devfs_name = "mapper/control",
1384 * Create misc character device and link to DM_DIR/control.
1386 int __init dm_interface_init(void)
1394 r = misc_register(&_dm_misc);
1396 DMERR("misc_register failed for control device");
1401 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1402 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1407 void dm_interface_exit(void)
1409 if (misc_deregister(&_dm_misc) < 0)
1410 DMERR("misc_deregister failed for control device");