2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 - 2006 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/dm-ioctl.h>
17 #include <linux/hdreg.h>
18 #include <linux/vs_context.h>
20 #include <asm/uaccess.h>
22 #define DM_MSG_PREFIX "ioctl"
23 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
25 /*-----------------------------------------------------------------
26 * The ioctl interface needs to be able to look up devices by
28 *---------------------------------------------------------------*/
30 struct list_head name_list;
31 struct list_head uuid_list;
35 struct mapped_device *md;
36 struct dm_table *new_map;
41 struct dm_target_versions *vers, *old_vers;
47 #define NUM_BUCKETS 64
48 #define MASK_BUCKETS (NUM_BUCKETS - 1)
49 static struct list_head _name_buckets[NUM_BUCKETS];
50 static struct list_head _uuid_buckets[NUM_BUCKETS];
52 static void dm_hash_remove_all(int keep_open_devices);
55 * Guards access to both hash tables.
57 static DECLARE_RWSEM(_hash_lock);
59 static void init_buckets(struct list_head *buckets)
63 for (i = 0; i < NUM_BUCKETS; i++)
64 INIT_LIST_HEAD(buckets + i);
67 static int dm_hash_init(void)
69 init_buckets(_name_buckets);
70 init_buckets(_uuid_buckets);
74 static void dm_hash_exit(void)
76 dm_hash_remove_all(0);
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 (vx_check(dm_get_xid(hc->md), VS_WATCH_P|VS_IDENT) &&
105 !strcmp(hc->name, str)) {
113 static struct hash_cell *__get_uuid_cell(const char *str)
115 struct hash_cell *hc;
116 unsigned int h = hash_str(str);
118 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
119 if (vx_check(dm_get_xid(hc->md), VS_WATCH_P|VS_IDENT) &&
120 !strcmp(hc->uuid, str)) {
128 /*-----------------------------------------------------------------
129 * Inserting, removing and renaming a device.
130 *---------------------------------------------------------------*/
131 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
132 struct mapped_device *md)
134 struct hash_cell *hc;
136 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
140 hc->name = kstrdup(name, GFP_KERNEL);
150 hc->uuid = kstrdup(uuid, GFP_KERNEL);
158 INIT_LIST_HEAD(&hc->name_list);
159 INIT_LIST_HEAD(&hc->uuid_list);
165 static void free_cell(struct hash_cell *hc)
175 * The kdev_t and uuid of a device can never change once it is
176 * initially inserted.
178 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
180 struct hash_cell *cell, *hc;
183 * Allocate the new cells.
185 cell = alloc_cell(name, uuid, md);
190 * Insert the cell into both hash tables.
192 down_write(&_hash_lock);
193 hc = __get_name_cell(name);
199 list_add(&cell->name_list, _name_buckets + hash_str(name));
202 hc = __get_uuid_cell(uuid);
204 list_del(&cell->name_list);
208 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
211 dm_set_mdptr(md, cell);
212 up_write(&_hash_lock);
217 up_write(&_hash_lock);
222 static void __hash_remove(struct hash_cell *hc)
224 struct dm_table *table;
226 /* remove from the dev hash */
227 list_del(&hc->uuid_list);
228 list_del(&hc->name_list);
229 dm_set_mdptr(hc->md, NULL);
231 table = dm_get_table(hc->md);
233 dm_table_event(table);
238 dm_table_put(hc->new_map);
243 static void dm_hash_remove_all(int keep_open_devices)
245 int i, dev_skipped, dev_removed;
246 struct hash_cell *hc;
247 struct list_head *tmp, *n;
249 down_write(&_hash_lock);
252 dev_skipped = dev_removed = 0;
253 for (i = 0; i < NUM_BUCKETS; i++) {
254 list_for_each_safe (tmp, n, _name_buckets + i) {
255 hc = list_entry(tmp, struct hash_cell, name_list);
257 if (keep_open_devices &&
258 dm_lock_for_deletion(hc->md)) {
268 * Some mapped devices may be using other mapped devices, so if any
269 * still exist, repeat until we make no further progress.
275 DMWARN("remove_all left %d open device(s)", dev_skipped);
278 up_write(&_hash_lock);
281 static int dm_hash_rename(const char *old, const char *new)
283 char *new_name, *old_name;
284 struct hash_cell *hc;
285 struct dm_table *table;
290 new_name = kstrdup(new, GFP_KERNEL);
294 down_write(&_hash_lock);
299 hc = __get_name_cell(new);
301 DMWARN("asked to rename to an already existing name %s -> %s",
304 up_write(&_hash_lock);
310 * Is there such a device as 'old' ?
312 hc = __get_name_cell(old);
314 DMWARN("asked to rename a non existent device %s -> %s",
316 up_write(&_hash_lock);
322 * rename and move the name cell.
324 list_del(&hc->name_list);
327 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
330 * Wake up any dm event waiters.
332 table = dm_get_table(hc->md);
334 dm_table_event(table);
339 up_write(&_hash_lock);
344 /*-----------------------------------------------------------------
345 * Implementation of the ioctl commands
346 *---------------------------------------------------------------*/
348 * All the ioctl commands get dispatched to functions with this
351 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
353 static int remove_all(struct dm_ioctl *param, size_t param_size)
355 if (!vx_check(0, VS_ADMIN))
358 dm_hash_remove_all(1);
359 param->data_size = 0;
364 * Round up the ptr to an 8-byte boundary.
367 static inline void *align_ptr(void *ptr)
369 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
373 * Retrieves the data payload buffer from an already allocated
376 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
379 param->data_start = align_ptr(param + 1) - (void *) param;
381 if (param->data_start < param_size)
382 *len = param_size - param->data_start;
386 return ((void *) param) + param->data_start;
389 static int list_devices(struct dm_ioctl *param, size_t param_size)
392 struct hash_cell *hc;
393 size_t len, needed = 0;
394 struct gendisk *disk;
395 struct dm_name_list *nl, *old_nl = NULL;
397 down_write(&_hash_lock);
400 * Loop through all the devices working out how much
403 for (i = 0; i < NUM_BUCKETS; i++) {
404 list_for_each_entry (hc, _name_buckets + i, name_list) {
405 if (!vx_check(dm_get_xid(hc->md), VS_WATCH_P|VS_IDENT))
407 needed += sizeof(struct dm_name_list);
408 needed += strlen(hc->name) + 1;
409 needed += ALIGN_MASK;
414 * Grab our output buffer.
416 nl = get_result_buffer(param, param_size, &len);
418 param->flags |= DM_BUFFER_FULL_FLAG;
421 param->data_size = param->data_start + needed;
423 nl->dev = 0; /* Flags no data */
426 * Now loop through filling out the names.
428 for (i = 0; i < NUM_BUCKETS; i++) {
429 list_for_each_entry (hc, _name_buckets + i, name_list) {
430 if (!vx_check(dm_get_xid(hc->md), VS_WATCH_P|VS_IDENT))
433 old_nl->next = (uint32_t) ((void *) nl -
435 disk = dm_disk(hc->md);
436 nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
438 strcpy(nl->name, hc->name);
441 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
446 up_write(&_hash_lock);
450 static void list_version_get_needed(struct target_type *tt, void *needed_param)
452 size_t *needed = needed_param;
454 *needed += sizeof(struct dm_target_versions);
455 *needed += strlen(tt->name);
456 *needed += ALIGN_MASK;
459 static void list_version_get_info(struct target_type *tt, void *param)
461 struct vers_iter *info = param;
463 /* Check space - it might have changed since the first iteration */
464 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
467 info->flags = DM_BUFFER_FULL_FLAG;
472 info->old_vers->next = (uint32_t) ((void *)info->vers -
473 (void *)info->old_vers);
474 info->vers->version[0] = tt->version[0];
475 info->vers->version[1] = tt->version[1];
476 info->vers->version[2] = tt->version[2];
477 info->vers->next = 0;
478 strcpy(info->vers->name, tt->name);
480 info->old_vers = info->vers;
481 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
484 static int list_versions(struct dm_ioctl *param, size_t param_size)
486 size_t len, needed = 0;
487 struct dm_target_versions *vers;
488 struct vers_iter iter_info;
491 * Loop through all the devices working out how much
494 dm_target_iterate(list_version_get_needed, &needed);
497 * Grab our output buffer.
499 vers = get_result_buffer(param, param_size, &len);
501 param->flags |= DM_BUFFER_FULL_FLAG;
504 param->data_size = param->data_start + needed;
506 iter_info.param_size = param_size;
507 iter_info.old_vers = NULL;
508 iter_info.vers = vers;
510 iter_info.end = (char *)vers+len;
513 * Now loop through filling out the names & versions.
515 dm_target_iterate(list_version_get_info, &iter_info);
516 param->flags |= iter_info.flags;
524 static int check_name(const char *name)
526 if (strchr(name, '/')) {
527 DMWARN("invalid device name");
535 * Fills in a dm_ioctl structure, ready for sending back to
538 static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
540 struct gendisk *disk = dm_disk(md);
541 struct dm_table *table;
543 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
544 DM_ACTIVE_PRESENT_FLAG);
546 if (dm_suspended(md))
547 param->flags |= DM_SUSPEND_FLAG;
549 param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
552 * Yes, this will be out of date by the time it gets back
553 * to userland, but it is still very useful for
556 param->open_count = dm_open_count(md);
559 param->flags |= DM_READONLY_FLAG;
561 param->event_nr = dm_get_event_nr(md);
563 table = dm_get_table(md);
565 param->flags |= DM_ACTIVE_PRESENT_FLAG;
566 param->target_count = dm_table_get_num_targets(table);
569 param->target_count = 0;
574 static int dev_create(struct dm_ioctl *param, size_t param_size)
576 int r, m = DM_ANY_MINOR;
577 struct mapped_device *md;
579 r = check_name(param->name);
583 if (param->flags & DM_PERSISTENT_DEV_FLAG)
584 m = MINOR(huge_decode_dev(param->dev));
586 r = dm_create(m, &md);
590 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
596 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
598 r = __dev_status(md, param);
605 * Always use UUID for lookups if it's present, otherwise use name or dev.
607 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
609 struct mapped_device *md;
613 return __get_uuid_cell(param->uuid);
616 return __get_name_cell(param->name);
618 md = dm_get_md(huge_decode_dev(param->dev));
622 if (vx_check(dm_get_xid(md), VS_WATCH_P|VS_IDENT))
623 mdptr = dm_get_mdptr(md);
631 static struct mapped_device *find_device(struct dm_ioctl *param)
633 struct hash_cell *hc;
634 struct mapped_device *md = NULL;
636 down_read(&_hash_lock);
637 hc = __find_device_hash_cell(param);
642 * Sneakily write in both the name and the uuid
643 * while we have the cell.
645 strncpy(param->name, hc->name, sizeof(param->name));
647 strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1);
649 param->uuid[0] = '\0';
652 param->flags |= DM_INACTIVE_PRESENT_FLAG;
654 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
656 up_read(&_hash_lock);
661 static int dev_remove(struct dm_ioctl *param, size_t param_size)
663 struct hash_cell *hc;
664 struct mapped_device *md;
667 down_write(&_hash_lock);
668 hc = __find_device_hash_cell(param);
671 DMWARN("device doesn't appear to be in the dev hash table.");
672 up_write(&_hash_lock);
679 * Ensure the device is not open and nothing further can open it.
681 r = dm_lock_for_deletion(md);
683 DMWARN("unable to remove open device %s", hc->name);
684 up_write(&_hash_lock);
690 up_write(&_hash_lock);
692 param->data_size = 0;
697 * Check a string doesn't overrun the chunk of
698 * memory we copied from userland.
700 static int invalid_str(char *str, void *end)
702 while ((void *) str < end)
709 static int dev_rename(struct dm_ioctl *param, size_t param_size)
712 char *new_name = (char *) param + param->data_start;
714 if (new_name < (char *) (param + 1) ||
715 invalid_str(new_name, (void *) param + param_size)) {
716 DMWARN("Invalid new logical volume name supplied.");
720 r = check_name(new_name);
724 param->data_size = 0;
725 return dm_hash_rename(param->name, new_name);
728 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
731 struct mapped_device *md;
732 struct hd_geometry geometry;
733 unsigned long indata[4];
734 char *geostr = (char *) param + param->data_start;
736 md = find_device(param);
740 if (geostr < (char *) (param + 1) ||
741 invalid_str(geostr, (void *) param + param_size)) {
742 DMWARN("Invalid geometry supplied.");
746 x = sscanf(geostr, "%lu %lu %lu %lu", indata,
747 indata + 1, indata + 2, indata + 3);
750 DMWARN("Unable to interpret geometry settings.");
754 if (indata[0] > 65535 || indata[1] > 255 ||
755 indata[2] > 255 || indata[3] > ULONG_MAX) {
756 DMWARN("Geometry exceeds range limits.");
760 geometry.cylinders = indata[0];
761 geometry.heads = indata[1];
762 geometry.sectors = indata[2];
763 geometry.start = indata[3];
765 r = dm_set_geometry(md, &geometry);
767 r = __dev_status(md, param);
769 param->data_size = 0;
776 static int do_suspend(struct dm_ioctl *param)
779 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
780 struct mapped_device *md;
782 md = find_device(param);
786 if (param->flags & DM_SKIP_LOCKFS_FLAG)
787 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
788 if (param->flags & DM_NOFLUSH_FLAG)
789 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
791 if (!dm_suspended(md))
792 r = dm_suspend(md, suspend_flags);
795 r = __dev_status(md, param);
801 static int do_resume(struct dm_ioctl *param)
804 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
805 struct hash_cell *hc;
806 struct mapped_device *md;
807 struct dm_table *new_map;
809 down_write(&_hash_lock);
811 hc = __find_device_hash_cell(param);
813 DMWARN("device doesn't appear to be in the dev hash table.");
814 up_write(&_hash_lock);
820 new_map = hc->new_map;
822 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
824 up_write(&_hash_lock);
826 /* Do we need to load a new map ? */
828 /* Suspend if it isn't already suspended */
829 if (param->flags & DM_SKIP_LOCKFS_FLAG)
830 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
831 if (param->flags & DM_NOFLUSH_FLAG)
832 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
833 if (!dm_suspended(md))
834 dm_suspend(md, suspend_flags);
836 r = dm_swap_table(md, new_map);
839 dm_table_put(new_map);
843 if (dm_table_get_mode(new_map) & FMODE_WRITE)
844 set_disk_ro(dm_disk(md), 0);
846 set_disk_ro(dm_disk(md), 1);
848 dm_table_put(new_map);
851 if (dm_suspended(md))
855 r = __dev_status(md, param);
862 * Set or unset the suspension state of a device.
863 * If the device already is in the requested state we just return its status.
865 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
867 if (param->flags & DM_SUSPEND_FLAG)
868 return do_suspend(param);
870 return do_resume(param);
874 * Copies device info back to user space, used by
875 * the create and info ioctls.
877 static int dev_status(struct dm_ioctl *param, size_t param_size)
880 struct mapped_device *md;
882 md = find_device(param);
886 r = __dev_status(md, param);
892 * Build up the status struct for each target
894 static void retrieve_status(struct dm_table *table,
895 struct dm_ioctl *param, size_t param_size)
897 unsigned int i, num_targets;
898 struct dm_target_spec *spec;
899 char *outbuf, *outptr;
901 size_t remaining, len, used = 0;
903 outptr = outbuf = get_result_buffer(param, param_size, &len);
905 if (param->flags & DM_STATUS_TABLE_FLAG)
906 type = STATUSTYPE_TABLE;
908 type = STATUSTYPE_INFO;
910 /* Get all the target info */
911 num_targets = dm_table_get_num_targets(table);
912 for (i = 0; i < num_targets; i++) {
913 struct dm_target *ti = dm_table_get_target(table, i);
915 remaining = len - (outptr - outbuf);
916 if (remaining <= sizeof(struct dm_target_spec)) {
917 param->flags |= DM_BUFFER_FULL_FLAG;
921 spec = (struct dm_target_spec *) outptr;
924 spec->sector_start = ti->begin;
925 spec->length = ti->len;
926 strncpy(spec->target_type, ti->type->name,
927 sizeof(spec->target_type));
929 outptr += sizeof(struct dm_target_spec);
930 remaining = len - (outptr - outbuf);
931 if (remaining <= 0) {
932 param->flags |= DM_BUFFER_FULL_FLAG;
936 /* Get the status/table string from the target driver */
937 if (ti->type->status) {
938 if (ti->type->status(ti, type, outptr, remaining)) {
939 param->flags |= DM_BUFFER_FULL_FLAG;
945 outptr += strlen(outptr) + 1;
946 used = param->data_start + (outptr - outbuf);
948 outptr = align_ptr(outptr);
949 spec->next = outptr - outbuf;
953 param->data_size = used;
955 param->target_count = num_targets;
959 * Wait for a device to report an event
961 static int dev_wait(struct dm_ioctl *param, size_t param_size)
964 struct mapped_device *md;
965 struct dm_table *table;
967 md = find_device(param);
972 * Wait for a notification event
974 if (dm_wait_event(md, param->event_nr)) {
980 * The userland program is going to want to know what
981 * changed to trigger the event, so we may as well tell
982 * him and save an ioctl.
984 r = __dev_status(md, param);
988 table = dm_get_table(md);
990 retrieve_status(table, param, param_size);
999 static inline int get_mode(struct dm_ioctl *param)
1001 int mode = FMODE_READ | FMODE_WRITE;
1003 if (param->flags & DM_READONLY_FLAG)
1009 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1010 struct dm_target_spec **spec, char **target_params)
1012 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1013 *target_params = (char *) (*spec + 1);
1015 if (*spec < (last + 1))
1018 return invalid_str(*target_params, end);
1021 static int populate_table(struct dm_table *table,
1022 struct dm_ioctl *param, size_t param_size)
1026 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1027 uint32_t next = param->data_start;
1028 void *end = (void *) param + param_size;
1029 char *target_params;
1031 if (!param->target_count) {
1032 DMWARN("populate_table: no targets specified");
1036 for (i = 0; i < param->target_count; i++) {
1038 r = next_target(spec, next, end, &spec, &target_params);
1040 DMWARN("unable to find target");
1044 r = dm_table_add_target(table, spec->target_type,
1045 (sector_t) spec->sector_start,
1046 (sector_t) spec->length,
1049 DMWARN("error adding target to table");
1056 return dm_table_complete(table);
1059 static int table_load(struct dm_ioctl *param, size_t param_size)
1062 struct hash_cell *hc;
1064 struct mapped_device *md;
1066 md = find_device(param);
1070 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1074 r = populate_table(t, param, param_size);
1080 down_write(&_hash_lock);
1081 hc = dm_get_mdptr(md);
1082 if (!hc || hc->md != md) {
1083 DMWARN("device has been removed from the dev hash table.");
1085 up_write(&_hash_lock);
1091 dm_table_put(hc->new_map);
1093 up_write(&_hash_lock);
1095 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1096 r = __dev_status(md, param);
1104 static int table_clear(struct dm_ioctl *param, size_t param_size)
1107 struct hash_cell *hc;
1108 struct mapped_device *md;
1110 down_write(&_hash_lock);
1112 hc = __find_device_hash_cell(param);
1114 DMWARN("device doesn't appear to be in the dev hash table.");
1115 up_write(&_hash_lock);
1120 dm_table_put(hc->new_map);
1124 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1126 r = __dev_status(hc->md, param);
1128 up_write(&_hash_lock);
1134 * Retrieves a list of devices used by a particular dm device.
1136 static void retrieve_deps(struct dm_table *table,
1137 struct dm_ioctl *param, size_t param_size)
1139 unsigned int count = 0;
1140 struct list_head *tmp;
1143 struct dm_target_deps *deps;
1145 deps = get_result_buffer(param, param_size, &len);
1148 * Count the devices.
1150 list_for_each (tmp, dm_table_get_devices(table))
1154 * Check we have enough space.
1156 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1158 param->flags |= DM_BUFFER_FULL_FLAG;
1163 * Fill in the devices.
1165 deps->count = count;
1167 list_for_each_entry (dd, dm_table_get_devices(table), list)
1168 deps->dev[count++] = huge_encode_dev(dd->bdev->bd_dev);
1170 param->data_size = param->data_start + needed;
1173 static int table_deps(struct dm_ioctl *param, size_t param_size)
1176 struct mapped_device *md;
1177 struct dm_table *table;
1179 md = find_device(param);
1183 r = __dev_status(md, param);
1187 table = dm_get_table(md);
1189 retrieve_deps(table, param, param_size);
1190 dm_table_put(table);
1199 * Return the status of a device as a text string for each
1202 static int table_status(struct dm_ioctl *param, size_t param_size)
1205 struct mapped_device *md;
1206 struct dm_table *table;
1208 md = find_device(param);
1212 r = __dev_status(md, param);
1216 table = dm_get_table(md);
1218 retrieve_status(table, param, param_size);
1219 dm_table_put(table);
1228 * Pass a message to the target that's at the supplied device offset.
1230 static int target_message(struct dm_ioctl *param, size_t param_size)
1234 struct mapped_device *md;
1235 struct dm_table *table;
1236 struct dm_target *ti;
1237 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1239 md = find_device(param);
1243 r = __dev_status(md, param);
1247 if (tmsg < (struct dm_target_msg *) (param + 1) ||
1248 invalid_str(tmsg->message, (void *) param + param_size)) {
1249 DMWARN("Invalid target message parameters.");
1254 r = dm_split_args(&argc, &argv, tmsg->message);
1256 DMWARN("Failed to split target message parameters");
1260 table = dm_get_table(md);
1264 if (tmsg->sector >= dm_table_get_size(table)) {
1265 DMWARN("Target message sector outside device.");
1270 ti = dm_table_find_target(table, tmsg->sector);
1271 if (ti->type->message)
1272 r = ti->type->message(ti, argc, argv);
1274 DMWARN("Target type does not support messages");
1279 dm_table_put(table);
1283 param->data_size = 0;
1288 /*-----------------------------------------------------------------
1289 * Implementation of open/close/ioctl on the special char
1291 *---------------------------------------------------------------*/
1292 static ioctl_fn lookup_ioctl(unsigned int cmd)
1298 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1299 {DM_REMOVE_ALL_CMD, remove_all},
1300 {DM_LIST_DEVICES_CMD, list_devices},
1302 {DM_DEV_CREATE_CMD, dev_create},
1303 {DM_DEV_REMOVE_CMD, dev_remove},
1304 {DM_DEV_RENAME_CMD, dev_rename},
1305 {DM_DEV_SUSPEND_CMD, dev_suspend},
1306 {DM_DEV_STATUS_CMD, dev_status},
1307 {DM_DEV_WAIT_CMD, dev_wait},
1309 {DM_TABLE_LOAD_CMD, table_load},
1310 {DM_TABLE_CLEAR_CMD, table_clear},
1311 {DM_TABLE_DEPS_CMD, table_deps},
1312 {DM_TABLE_STATUS_CMD, table_status},
1314 {DM_LIST_VERSIONS_CMD, list_versions},
1316 {DM_TARGET_MSG_CMD, target_message},
1317 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1320 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1324 * As well as checking the version compatibility this always
1325 * copies the kernel interface version out.
1327 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1329 uint32_t version[3];
1332 if (copy_from_user(version, user->version, sizeof(version)))
1335 if ((DM_VERSION_MAJOR != version[0]) ||
1336 (DM_VERSION_MINOR < version[1])) {
1337 DMWARN("ioctl interface mismatch: "
1338 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1339 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1340 DM_VERSION_PATCHLEVEL,
1341 version[0], version[1], version[2], cmd);
1346 * Fill in the kernel version.
1348 version[0] = DM_VERSION_MAJOR;
1349 version[1] = DM_VERSION_MINOR;
1350 version[2] = DM_VERSION_PATCHLEVEL;
1351 if (copy_to_user(user->version, version, sizeof(version)))
1357 static void free_params(struct dm_ioctl *param)
1362 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1364 struct dm_ioctl tmp, *dmi;
1366 if (copy_from_user(&tmp, user, sizeof(tmp)))
1369 if (tmp.data_size < sizeof(tmp))
1372 dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
1376 if (copy_from_user(dmi, user, tmp.data_size)) {
1385 static int validate_params(uint cmd, struct dm_ioctl *param)
1387 /* Always clear this flag */
1388 param->flags &= ~DM_BUFFER_FULL_FLAG;
1390 /* Ignores parameters */
1391 if (cmd == DM_REMOVE_ALL_CMD ||
1392 cmd == DM_LIST_DEVICES_CMD ||
1393 cmd == DM_LIST_VERSIONS_CMD)
1396 if ((cmd == DM_DEV_CREATE_CMD)) {
1397 if (!*param->name) {
1398 DMWARN("name not supplied when creating device");
1401 } else if ((*param->uuid && *param->name)) {
1402 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1406 /* Ensure strings are terminated */
1407 param->name[DM_NAME_LEN - 1] = '\0';
1408 param->uuid[DM_UUID_LEN - 1] = '\0';
1413 static int ctl_ioctl(struct inode *inode, struct file *file,
1414 uint command, ulong u)
1418 struct dm_ioctl *param;
1419 struct dm_ioctl __user *user = (struct dm_ioctl __user *) u;
1423 /* only root and certain contexts can play with this */
1424 if (!vx_capable(CAP_SYS_ADMIN, VXC_ADMIN_MAPPER))
1427 if (_IOC_TYPE(command) != DM_IOCTL)
1430 cmd = _IOC_NR(command);
1433 * Check the interface version passed in. This also
1434 * writes out the kernel's interface version.
1436 r = check_version(cmd, user);
1441 * Nothing more to do for the version command.
1443 if (cmd == DM_VERSION_CMD)
1446 fn = lookup_ioctl(cmd);
1448 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1453 * Trying to avoid low memory issues when a device is
1456 current->flags |= PF_MEMALLOC;
1459 * Copy the parameters into kernel space.
1461 r = copy_params(user, ¶m);
1463 current->flags &= ~PF_MEMALLOC;
1468 r = validate_params(cmd, param);
1472 param_size = param->data_size;
1473 param->data_size = sizeof(*param);
1474 r = fn(param, param_size);
1477 * Copy the results back to userland.
1479 if (!r && copy_to_user(user, param, param->data_size))
1487 static struct file_operations _ctl_fops = {
1489 .owner = THIS_MODULE,
1492 static struct miscdevice _dm_misc = {
1493 .minor = MISC_DYNAMIC_MINOR,
1499 * Create misc character device and link to DM_DIR/control.
1501 int __init dm_interface_init(void)
1509 r = misc_register(&_dm_misc);
1511 DMERR("misc_register failed for control device");
1516 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1517 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1522 void dm_interface_exit(void)
1524 if (misc_deregister(&_dm_misc) < 0)
1525 DMERR("misc_deregister failed for control device");