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/compat.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;
40 * A dummy definition to make RCU happy.
41 * struct dm_table should never be dereferenced in this file.
49 struct dm_target_versions *vers, *old_vers;
55 #define NUM_BUCKETS 64
56 #define MASK_BUCKETS (NUM_BUCKETS - 1)
57 static struct list_head _name_buckets[NUM_BUCKETS];
58 static struct list_head _uuid_buckets[NUM_BUCKETS];
60 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
63 * Guards access to both hash tables.
65 static DECLARE_RWSEM(_hash_lock);
68 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
70 static DEFINE_MUTEX(dm_hash_cells_mutex);
72 static void init_buckets(struct list_head *buckets)
76 for (i = 0; i < NUM_BUCKETS; i++)
77 INIT_LIST_HEAD(buckets + i);
80 static int dm_hash_init(void)
82 init_buckets(_name_buckets);
83 init_buckets(_uuid_buckets);
87 static void dm_hash_exit(void)
89 dm_hash_remove_all(false, false, false);
92 /*-----------------------------------------------------------------
94 * We're not really concerned with the str hash function being
95 * fast since it's only used by the ioctl interface.
96 *---------------------------------------------------------------*/
97 static unsigned int hash_str(const char *str)
99 const unsigned int hash_mult = 2654435387U;
103 h = (h + (unsigned int) *str++) * hash_mult;
105 return h & MASK_BUCKETS;
108 /*-----------------------------------------------------------------
109 * Code for looking up a device by name
110 *---------------------------------------------------------------*/
111 static struct hash_cell *__get_name_cell(const char *str)
113 struct hash_cell *hc;
114 unsigned int h = hash_str(str);
116 list_for_each_entry (hc, _name_buckets + h, name_list)
117 if (!strcmp(hc->name, str)) {
125 static struct hash_cell *__get_uuid_cell(const char *str)
127 struct hash_cell *hc;
128 unsigned int h = hash_str(str);
130 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
131 if (!strcmp(hc->uuid, str)) {
139 static struct hash_cell *__get_dev_cell(uint64_t dev)
141 struct mapped_device *md;
142 struct hash_cell *hc;
144 md = dm_get_md(huge_decode_dev(dev));
148 hc = dm_get_mdptr(md);
157 /*-----------------------------------------------------------------
158 * Inserting, removing and renaming a device.
159 *---------------------------------------------------------------*/
160 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
161 struct mapped_device *md)
163 struct hash_cell *hc;
165 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
169 hc->name = kstrdup(name, GFP_KERNEL);
179 hc->uuid = kstrdup(uuid, GFP_KERNEL);
187 INIT_LIST_HEAD(&hc->name_list);
188 INIT_LIST_HEAD(&hc->uuid_list);
194 static void free_cell(struct hash_cell *hc)
204 * The kdev_t and uuid of a device can never change once it is
205 * initially inserted.
207 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
209 struct hash_cell *cell, *hc;
212 * Allocate the new cells.
214 cell = alloc_cell(name, uuid, md);
219 * Insert the cell into both hash tables.
221 down_write(&_hash_lock);
222 hc = __get_name_cell(name);
228 list_add(&cell->name_list, _name_buckets + hash_str(name));
231 hc = __get_uuid_cell(uuid);
233 list_del(&cell->name_list);
237 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
240 mutex_lock(&dm_hash_cells_mutex);
241 dm_set_mdptr(md, cell);
242 mutex_unlock(&dm_hash_cells_mutex);
243 up_write(&_hash_lock);
248 up_write(&_hash_lock);
253 static struct dm_table *__hash_remove(struct hash_cell *hc)
255 struct dm_table *table;
258 /* remove from the dev hash */
259 list_del(&hc->uuid_list);
260 list_del(&hc->name_list);
261 mutex_lock(&dm_hash_cells_mutex);
262 dm_set_mdptr(hc->md, NULL);
263 mutex_unlock(&dm_hash_cells_mutex);
265 table = dm_get_live_table(hc->md, &srcu_idx);
267 dm_table_event(table);
268 dm_put_live_table(hc->md, srcu_idx);
279 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
282 struct hash_cell *hc;
283 struct mapped_device *md;
289 down_write(&_hash_lock);
291 for (i = 0; i < NUM_BUCKETS; i++) {
292 list_for_each_entry(hc, _name_buckets + i, name_list) {
296 if (keep_open_devices &&
297 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
303 t = __hash_remove(hc);
305 up_write(&_hash_lock);
312 if (likely(keep_open_devices))
315 dm_destroy_immediate(md);
318 * Some mapped devices may be using other mapped
319 * devices, so repeat until we make no further
320 * progress. If a new mapped device is created
321 * here it will also get removed.
327 up_write(&_hash_lock);
330 DMWARN("remove_all left %d open device(s)", dev_skipped);
334 * Set the uuid of a hash_cell that isn't already set.
336 static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
338 mutex_lock(&dm_hash_cells_mutex);
340 mutex_unlock(&dm_hash_cells_mutex);
342 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
346 * Changes the name of a hash_cell and returns the old name for
347 * the caller to free.
349 static char *__change_cell_name(struct hash_cell *hc, char *new_name)
354 * Rename and move the name cell.
356 list_del(&hc->name_list);
359 mutex_lock(&dm_hash_cells_mutex);
361 mutex_unlock(&dm_hash_cells_mutex);
363 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
368 static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
371 char *new_data, *old_name = NULL;
372 struct hash_cell *hc;
373 struct dm_table *table;
374 struct mapped_device *md;
375 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
381 new_data = kstrdup(new, GFP_KERNEL);
383 return ERR_PTR(-ENOMEM);
385 down_write(&_hash_lock);
391 hc = __get_uuid_cell(new);
393 hc = __get_name_cell(new);
396 DMWARN("Unable to change %s on mapped device %s to one that "
397 "already exists: %s",
398 change_uuid ? "uuid" : "name",
401 up_write(&_hash_lock);
403 return ERR_PTR(-EBUSY);
407 * Is there such a device as 'old' ?
409 hc = __get_name_cell(param->name);
411 DMWARN("Unable to rename non-existent device, %s to %s%s",
412 param->name, change_uuid ? "uuid " : "", new);
413 up_write(&_hash_lock);
415 return ERR_PTR(-ENXIO);
419 * Does this device already have a uuid?
421 if (change_uuid && hc->uuid) {
422 DMWARN("Unable to change uuid of mapped device %s to %s "
423 "because uuid is already set to %s",
424 param->name, new, hc->uuid);
426 up_write(&_hash_lock);
428 return ERR_PTR(-EINVAL);
432 __set_cell_uuid(hc, new_data);
434 old_name = __change_cell_name(hc, new_data);
437 * Wake up any dm event waiters.
439 table = dm_get_live_table(hc->md, &srcu_idx);
441 dm_table_event(table);
442 dm_put_live_table(hc->md, srcu_idx);
444 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
445 param->flags |= DM_UEVENT_GENERATED_FLAG;
448 up_write(&_hash_lock);
454 void dm_deferred_remove(void)
456 dm_hash_remove_all(true, false, true);
459 /*-----------------------------------------------------------------
460 * Implementation of the ioctl commands
461 *---------------------------------------------------------------*/
463 * All the ioctl commands get dispatched to functions with this
466 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
468 static int remove_all(struct dm_ioctl *param, size_t param_size)
470 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
471 param->data_size = 0;
476 * Round up the ptr to an 8-byte boundary.
479 static inline void *align_ptr(void *ptr)
481 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
485 * Retrieves the data payload buffer from an already allocated
488 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
491 param->data_start = align_ptr(param + 1) - (void *) param;
493 if (param->data_start < param_size)
494 *len = param_size - param->data_start;
498 return ((void *) param) + param->data_start;
501 static int list_devices(struct dm_ioctl *param, size_t param_size)
504 struct hash_cell *hc;
505 size_t len, needed = 0;
506 struct gendisk *disk;
507 struct dm_name_list *nl, *old_nl = NULL;
509 down_write(&_hash_lock);
512 * Loop through all the devices working out how much
515 for (i = 0; i < NUM_BUCKETS; i++) {
516 list_for_each_entry (hc, _name_buckets + i, name_list) {
517 needed += sizeof(struct dm_name_list);
518 needed += strlen(hc->name) + 1;
519 needed += ALIGN_MASK;
524 * Grab our output buffer.
526 nl = get_result_buffer(param, param_size, &len);
528 param->flags |= DM_BUFFER_FULL_FLAG;
531 param->data_size = param->data_start + needed;
533 nl->dev = 0; /* Flags no data */
536 * Now loop through filling out the names.
538 for (i = 0; i < NUM_BUCKETS; i++) {
539 list_for_each_entry (hc, _name_buckets + i, name_list) {
541 old_nl->next = (uint32_t) ((void *) nl -
543 disk = dm_disk(hc->md);
544 nl->dev = huge_encode_dev(disk_devt(disk));
546 strcpy(nl->name, hc->name);
549 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
554 up_write(&_hash_lock);
558 static void list_version_get_needed(struct target_type *tt, void *needed_param)
560 size_t *needed = needed_param;
562 *needed += sizeof(struct dm_target_versions);
563 *needed += strlen(tt->name);
564 *needed += ALIGN_MASK;
567 static void list_version_get_info(struct target_type *tt, void *param)
569 struct vers_iter *info = param;
571 /* Check space - it might have changed since the first iteration */
572 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
575 info->flags = DM_BUFFER_FULL_FLAG;
580 info->old_vers->next = (uint32_t) ((void *)info->vers -
581 (void *)info->old_vers);
582 info->vers->version[0] = tt->version[0];
583 info->vers->version[1] = tt->version[1];
584 info->vers->version[2] = tt->version[2];
585 info->vers->next = 0;
586 strcpy(info->vers->name, tt->name);
588 info->old_vers = info->vers;
589 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
592 static int list_versions(struct dm_ioctl *param, size_t param_size)
594 size_t len, needed = 0;
595 struct dm_target_versions *vers;
596 struct vers_iter iter_info;
599 * Loop through all the devices working out how much
602 dm_target_iterate(list_version_get_needed, &needed);
605 * Grab our output buffer.
607 vers = get_result_buffer(param, param_size, &len);
609 param->flags |= DM_BUFFER_FULL_FLAG;
612 param->data_size = param->data_start + needed;
614 iter_info.param_size = param_size;
615 iter_info.old_vers = NULL;
616 iter_info.vers = vers;
618 iter_info.end = (char *)vers+len;
621 * Now loop through filling out the names & versions.
623 dm_target_iterate(list_version_get_info, &iter_info);
624 param->flags |= iter_info.flags;
630 static int check_name(const char *name)
632 if (strchr(name, '/')) {
633 DMWARN("invalid device name");
641 * On successful return, the caller must not attempt to acquire
642 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
643 * waits for this dm_put_live_table and could be called under this lock.
645 static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
647 struct hash_cell *hc;
648 struct dm_table *table = NULL;
650 /* increment rcu count, we don't care about the table pointer */
651 dm_get_live_table(md, srcu_idx);
653 down_read(&_hash_lock);
654 hc = dm_get_mdptr(md);
655 if (!hc || hc->md != md) {
656 DMWARN("device has been removed from the dev hash table.");
663 up_read(&_hash_lock);
668 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
669 struct dm_ioctl *param,
672 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
673 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
677 * Fills in a dm_ioctl structure, ready for sending back to
680 static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
682 struct gendisk *disk = dm_disk(md);
683 struct dm_table *table;
686 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
687 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
689 if (dm_suspended_md(md))
690 param->flags |= DM_SUSPEND_FLAG;
692 if (dm_suspended_internally_md(md))
693 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
695 if (dm_test_deferred_remove_flag(md))
696 param->flags |= DM_DEFERRED_REMOVE;
698 param->dev = huge_encode_dev(disk_devt(disk));
701 * Yes, this will be out of date by the time it gets back
702 * to userland, but it is still very useful for
705 param->open_count = dm_open_count(md);
707 param->event_nr = dm_get_event_nr(md);
708 param->target_count = 0;
710 table = dm_get_live_table(md, &srcu_idx);
712 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
713 if (get_disk_ro(disk))
714 param->flags |= DM_READONLY_FLAG;
715 param->target_count = dm_table_get_num_targets(table);
718 param->flags |= DM_ACTIVE_PRESENT_FLAG;
720 dm_put_live_table(md, srcu_idx);
722 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
724 table = dm_get_inactive_table(md, &srcu_idx);
726 if (!(dm_table_get_mode(table) & FMODE_WRITE))
727 param->flags |= DM_READONLY_FLAG;
728 param->target_count = dm_table_get_num_targets(table);
730 dm_put_live_table(md, srcu_idx);
734 static int dev_create(struct dm_ioctl *param, size_t param_size)
736 int r, m = DM_ANY_MINOR;
737 struct mapped_device *md;
739 r = check_name(param->name);
743 if (param->flags & DM_PERSISTENT_DEV_FLAG)
744 m = MINOR(huge_decode_dev(param->dev));
746 r = dm_create(m, &md);
750 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
757 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
759 __dev_status(md, param);
767 * Always use UUID for lookups if it's present, otherwise use name or dev.
769 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
771 struct hash_cell *hc = NULL;
774 if (*param->name || param->dev)
777 hc = __get_uuid_cell(param->uuid);
780 } else if (*param->name) {
784 hc = __get_name_cell(param->name);
787 } else if (param->dev) {
788 hc = __get_dev_cell(param->dev);
795 * Sneakily write in both the name and the uuid
796 * while we have the cell.
798 strlcpy(param->name, hc->name, sizeof(param->name));
800 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
802 param->uuid[0] = '\0';
805 param->flags |= DM_INACTIVE_PRESENT_FLAG;
807 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
812 static struct mapped_device *find_device(struct dm_ioctl *param)
814 struct hash_cell *hc;
815 struct mapped_device *md = NULL;
817 down_read(&_hash_lock);
818 hc = __find_device_hash_cell(param);
821 up_read(&_hash_lock);
826 static int dev_remove(struct dm_ioctl *param, size_t param_size)
828 struct hash_cell *hc;
829 struct mapped_device *md;
833 down_write(&_hash_lock);
834 hc = __find_device_hash_cell(param);
837 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
838 up_write(&_hash_lock);
845 * Ensure the device is not open and nothing further can open it.
847 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
849 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
850 up_write(&_hash_lock);
854 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
855 up_write(&_hash_lock);
860 t = __hash_remove(hc);
861 up_write(&_hash_lock);
868 param->flags &= ~DM_DEFERRED_REMOVE;
870 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
871 param->flags |= DM_UEVENT_GENERATED_FLAG;
879 * Check a string doesn't overrun the chunk of
880 * memory we copied from userland.
882 static int invalid_str(char *str, void *end)
884 while ((void *) str < end)
891 static int dev_rename(struct dm_ioctl *param, size_t param_size)
894 char *new_data = (char *) param + param->data_start;
895 struct mapped_device *md;
896 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
898 if (new_data < param->data ||
899 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
900 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
901 DMWARN("Invalid new mapped device name or uuid string supplied.");
906 r = check_name(new_data);
911 md = dm_hash_rename(param, new_data);
915 __dev_status(md, param);
921 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
924 struct mapped_device *md;
925 struct hd_geometry geometry;
926 unsigned long indata[4];
927 char *geostr = (char *) param + param->data_start;
930 md = find_device(param);
934 if (geostr < param->data ||
935 invalid_str(geostr, (void *) param + param_size)) {
936 DMWARN("Invalid geometry supplied.");
940 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
941 indata + 1, indata + 2, indata + 3, &dummy);
944 DMWARN("Unable to interpret geometry settings.");
948 if (indata[0] > 65535 || indata[1] > 255 ||
949 indata[2] > 255 || indata[3] > ULONG_MAX) {
950 DMWARN("Geometry exceeds range limits.");
954 geometry.cylinders = indata[0];
955 geometry.heads = indata[1];
956 geometry.sectors = indata[2];
957 geometry.start = indata[3];
959 r = dm_set_geometry(md, &geometry);
961 param->data_size = 0;
968 static int do_suspend(struct dm_ioctl *param)
971 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
972 struct mapped_device *md;
974 md = find_device(param);
978 if (param->flags & DM_SKIP_LOCKFS_FLAG)
979 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
980 if (param->flags & DM_NOFLUSH_FLAG)
981 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
983 if (!dm_suspended_md(md)) {
984 r = dm_suspend(md, suspend_flags);
989 __dev_status(md, param);
997 static int do_resume(struct dm_ioctl *param)
1000 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1001 struct hash_cell *hc;
1002 struct mapped_device *md;
1003 struct dm_table *new_map, *old_map = NULL;
1005 down_write(&_hash_lock);
1007 hc = __find_device_hash_cell(param);
1009 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1010 up_write(&_hash_lock);
1016 new_map = hc->new_map;
1018 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1020 up_write(&_hash_lock);
1022 /* Do we need to load a new map ? */
1024 /* Suspend if it isn't already suspended */
1025 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1026 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1027 if (param->flags & DM_NOFLUSH_FLAG)
1028 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1029 if (!dm_suspended_md(md))
1030 dm_suspend(md, suspend_flags);
1032 old_map = dm_swap_table(md, new_map);
1033 if (IS_ERR(old_map)) {
1035 dm_table_destroy(new_map);
1037 return PTR_ERR(old_map);
1040 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1041 set_disk_ro(dm_disk(md), 0);
1043 set_disk_ro(dm_disk(md), 1);
1046 if (dm_suspended_md(md)) {
1048 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1049 param->flags |= DM_UEVENT_GENERATED_FLAG;
1053 * Since dm_swap_table synchronizes RCU, nobody should be in
1054 * read-side critical section already.
1057 dm_table_destroy(old_map);
1060 __dev_status(md, param);
1067 * Set or unset the suspension state of a device.
1068 * If the device already is in the requested state we just return its status.
1070 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
1072 if (param->flags & DM_SUSPEND_FLAG)
1073 return do_suspend(param);
1075 return do_resume(param);
1079 * Copies device info back to user space, used by
1080 * the create and info ioctls.
1082 static int dev_status(struct dm_ioctl *param, size_t param_size)
1084 struct mapped_device *md;
1086 md = find_device(param);
1090 __dev_status(md, param);
1097 * Build up the status struct for each target
1099 static void retrieve_status(struct dm_table *table,
1100 struct dm_ioctl *param, size_t param_size)
1102 unsigned int i, num_targets;
1103 struct dm_target_spec *spec;
1104 char *outbuf, *outptr;
1106 size_t remaining, len, used = 0;
1107 unsigned status_flags = 0;
1109 outptr = outbuf = get_result_buffer(param, param_size, &len);
1111 if (param->flags & DM_STATUS_TABLE_FLAG)
1112 type = STATUSTYPE_TABLE;
1114 type = STATUSTYPE_INFO;
1116 /* Get all the target info */
1117 num_targets = dm_table_get_num_targets(table);
1118 for (i = 0; i < num_targets; i++) {
1119 struct dm_target *ti = dm_table_get_target(table, i);
1122 remaining = len - (outptr - outbuf);
1123 if (remaining <= sizeof(struct dm_target_spec)) {
1124 param->flags |= DM_BUFFER_FULL_FLAG;
1128 spec = (struct dm_target_spec *) outptr;
1131 spec->sector_start = ti->begin;
1132 spec->length = ti->len;
1133 strncpy(spec->target_type, ti->type->name,
1134 sizeof(spec->target_type));
1136 outptr += sizeof(struct dm_target_spec);
1137 remaining = len - (outptr - outbuf);
1138 if (remaining <= 0) {
1139 param->flags |= DM_BUFFER_FULL_FLAG;
1143 /* Get the status/table string from the target driver */
1144 if (ti->type->status) {
1145 if (param->flags & DM_NOFLUSH_FLAG)
1146 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1147 ti->type->status(ti, type, status_flags, outptr, remaining);
1151 l = strlen(outptr) + 1;
1152 if (l == remaining) {
1153 param->flags |= DM_BUFFER_FULL_FLAG;
1158 used = param->data_start + (outptr - outbuf);
1160 outptr = align_ptr(outptr);
1161 spec->next = outptr - outbuf;
1165 param->data_size = used;
1167 param->target_count = num_targets;
1171 * Wait for a device to report an event
1173 static int dev_wait(struct dm_ioctl *param, size_t param_size)
1176 struct mapped_device *md;
1177 struct dm_table *table;
1180 md = find_device(param);
1185 * Wait for a notification event
1187 if (dm_wait_event(md, param->event_nr)) {
1193 * The userland program is going to want to know what
1194 * changed to trigger the event, so we may as well tell
1195 * him and save an ioctl.
1197 __dev_status(md, param);
1199 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1201 retrieve_status(table, param, param_size);
1202 dm_put_live_table(md, srcu_idx);
1210 static inline fmode_t get_mode(struct dm_ioctl *param)
1212 fmode_t mode = FMODE_READ | FMODE_WRITE;
1214 if (param->flags & DM_READONLY_FLAG)
1220 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1221 struct dm_target_spec **spec, char **target_params)
1223 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1224 *target_params = (char *) (*spec + 1);
1226 if (*spec < (last + 1))
1229 return invalid_str(*target_params, end);
1232 static int populate_table(struct dm_table *table,
1233 struct dm_ioctl *param, size_t param_size)
1237 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1238 uint32_t next = param->data_start;
1239 void *end = (void *) param + param_size;
1240 char *target_params;
1242 if (!param->target_count) {
1243 DMWARN("populate_table: no targets specified");
1247 for (i = 0; i < param->target_count; i++) {
1249 r = next_target(spec, next, end, &spec, &target_params);
1251 DMWARN("unable to find target");
1255 r = dm_table_add_target(table, spec->target_type,
1256 (sector_t) spec->sector_start,
1257 (sector_t) spec->length,
1260 DMWARN("error adding target to table");
1267 return dm_table_complete(table);
1270 static int table_load(struct dm_ioctl *param, size_t param_size)
1273 struct hash_cell *hc;
1274 struct dm_table *t, *old_map = NULL;
1275 struct mapped_device *md;
1276 struct target_type *immutable_target_type;
1278 md = find_device(param);
1282 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1286 /* Protect md->type and md->queue against concurrent table loads. */
1287 dm_lock_md_type(md);
1288 r = populate_table(t, param, param_size);
1290 goto err_unlock_md_type;
1292 immutable_target_type = dm_get_immutable_target_type(md);
1293 if (immutable_target_type &&
1294 (immutable_target_type != dm_table_get_immutable_target_type(t))) {
1295 DMWARN("can't replace immutable target type %s",
1296 immutable_target_type->name);
1298 goto err_unlock_md_type;
1301 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1302 /* Initial table load: acquire type of table. */
1303 dm_set_md_type(md, dm_table_get_type(t));
1305 /* setup md->queue to reflect md's type (may block) */
1306 r = dm_setup_md_queue(md);
1308 DMWARN("unable to set up device queue for new table.");
1309 goto err_unlock_md_type;
1311 } else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1312 DMWARN("can't change device type after initial table load.");
1314 goto err_unlock_md_type;
1317 dm_unlock_md_type(md);
1319 /* stage inactive table */
1320 down_write(&_hash_lock);
1321 hc = dm_get_mdptr(md);
1322 if (!hc || hc->md != md) {
1323 DMWARN("device has been removed from the dev hash table.");
1324 up_write(&_hash_lock);
1326 goto err_destroy_table;
1330 old_map = hc->new_map;
1332 up_write(&_hash_lock);
1334 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1335 __dev_status(md, param);
1339 dm_table_destroy(old_map);
1347 dm_unlock_md_type(md);
1349 dm_table_destroy(t);
1356 static int table_clear(struct dm_ioctl *param, size_t param_size)
1358 struct hash_cell *hc;
1359 struct mapped_device *md;
1360 struct dm_table *old_map = NULL;
1362 down_write(&_hash_lock);
1364 hc = __find_device_hash_cell(param);
1366 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1367 up_write(&_hash_lock);
1372 old_map = hc->new_map;
1376 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1378 __dev_status(hc->md, param);
1380 up_write(&_hash_lock);
1383 dm_table_destroy(old_map);
1391 * Retrieves a list of devices used by a particular dm device.
1393 static void retrieve_deps(struct dm_table *table,
1394 struct dm_ioctl *param, size_t param_size)
1396 unsigned int count = 0;
1397 struct list_head *tmp;
1399 struct dm_dev_internal *dd;
1400 struct dm_target_deps *deps;
1402 deps = get_result_buffer(param, param_size, &len);
1405 * Count the devices.
1407 list_for_each (tmp, dm_table_get_devices(table))
1411 * Check we have enough space.
1413 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1415 param->flags |= DM_BUFFER_FULL_FLAG;
1420 * Fill in the devices.
1422 deps->count = count;
1424 list_for_each_entry (dd, dm_table_get_devices(table), list)
1425 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1427 param->data_size = param->data_start + needed;
1430 static int table_deps(struct dm_ioctl *param, size_t param_size)
1432 struct mapped_device *md;
1433 struct dm_table *table;
1436 md = find_device(param);
1440 __dev_status(md, param);
1442 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1444 retrieve_deps(table, param, param_size);
1445 dm_put_live_table(md, srcu_idx);
1453 * Return the status of a device as a text string for each
1456 static int table_status(struct dm_ioctl *param, size_t param_size)
1458 struct mapped_device *md;
1459 struct dm_table *table;
1462 md = find_device(param);
1466 __dev_status(md, param);
1468 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1470 retrieve_status(table, param, param_size);
1471 dm_put_live_table(md, srcu_idx);
1479 * Process device-mapper dependent messages. Messages prefixed with '@'
1480 * are processed by the DM core. All others are delivered to the target.
1481 * Returns a number <= 1 if message was processed by device mapper.
1482 * Returns 2 if message should be delivered to the target.
1484 static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
1485 char *result, unsigned maxlen)
1490 return 2; /* no '@' prefix, deliver to target */
1492 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1494 DMERR("Invalid arguments for @cancel_deferred_remove");
1497 return dm_cancel_deferred_remove(md);
1500 r = dm_stats_message(md, argc, argv, result, maxlen);
1504 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1509 * Pass a message to the target that's at the supplied device offset.
1511 static int target_message(struct dm_ioctl *param, size_t param_size)
1515 struct mapped_device *md;
1516 struct dm_table *table;
1517 struct dm_target *ti;
1518 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1520 char *result = get_result_buffer(param, param_size, &maxlen);
1523 md = find_device(param);
1527 if (tmsg < (struct dm_target_msg *) param->data ||
1528 invalid_str(tmsg->message, (void *) param + param_size)) {
1529 DMWARN("Invalid target message parameters.");
1534 r = dm_split_args(&argc, &argv, tmsg->message);
1536 DMWARN("Failed to split target message parameters");
1541 DMWARN("Empty message received.");
1545 r = message_for_md(md, argc, argv, result, maxlen);
1549 table = dm_get_live_table(md, &srcu_idx);
1553 if (dm_deleting_md(md)) {
1558 ti = dm_table_find_target(table, tmsg->sector);
1559 if (!dm_target_is_valid(ti)) {
1560 DMWARN("Target message sector outside device.");
1562 } else if (ti->type->message)
1563 r = ti->type->message(ti, argc, argv);
1565 DMWARN("Target type does not support messages");
1570 dm_put_live_table(md, srcu_idx);
1575 __dev_status(md, param);
1578 param->flags |= DM_DATA_OUT_FLAG;
1579 if (dm_message_test_buffer_overflow(result, maxlen))
1580 param->flags |= DM_BUFFER_FULL_FLAG;
1582 param->data_size = param->data_start + strlen(result) + 1;
1591 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1592 * followed by a data buffer. This flag is set if the second part,
1593 * which has a variable size, is not used by the function processing
1596 #define IOCTL_FLAGS_NO_PARAMS 1
1598 /*-----------------------------------------------------------------
1599 * Implementation of open/close/ioctl on the special char
1601 *---------------------------------------------------------------*/
1602 static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1609 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1610 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all},
1611 {DM_LIST_DEVICES_CMD, 0, list_devices},
1613 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create},
1614 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove},
1615 {DM_DEV_RENAME_CMD, 0, dev_rename},
1616 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1617 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1618 {DM_DEV_WAIT_CMD, 0, dev_wait},
1620 {DM_TABLE_LOAD_CMD, 0, table_load},
1621 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1622 {DM_TABLE_DEPS_CMD, 0, table_deps},
1623 {DM_TABLE_STATUS_CMD, 0, table_status},
1625 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1627 {DM_TARGET_MSG_CMD, 0, target_message},
1628 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry}
1631 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1634 *ioctl_flags = _ioctls[cmd].flags;
1635 return _ioctls[cmd].fn;
1639 * As well as checking the version compatibility this always
1640 * copies the kernel interface version out.
1642 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1644 uint32_t version[3];
1647 if (copy_from_user(version, user->version, sizeof(version)))
1650 if ((DM_VERSION_MAJOR != version[0]) ||
1651 (DM_VERSION_MINOR < version[1])) {
1652 DMWARN("ioctl interface mismatch: "
1653 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1654 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1655 DM_VERSION_PATCHLEVEL,
1656 version[0], version[1], version[2], cmd);
1661 * Fill in the kernel version.
1663 version[0] = DM_VERSION_MAJOR;
1664 version[1] = DM_VERSION_MINOR;
1665 version[2] = DM_VERSION_PATCHLEVEL;
1666 if (copy_to_user(user->version, version, sizeof(version)))
1672 #define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */
1673 #define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */
1674 #define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1676 static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1678 if (param_flags & DM_WIPE_BUFFER)
1679 memset(param, 0, param_size);
1681 if (param_flags & DM_PARAMS_KMALLOC)
1683 if (param_flags & DM_PARAMS_VMALLOC)
1687 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1689 struct dm_ioctl **param, int *param_flags)
1691 struct dm_ioctl *dmi;
1693 const size_t minimum_data_size = sizeof(*param_kernel) - sizeof(param_kernel->data);
1695 if (copy_from_user(param_kernel, user, minimum_data_size))
1698 if (param_kernel->data_size < minimum_data_size)
1701 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1703 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1705 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1707 dmi->data_size = minimum_data_size;
1712 * Try to avoid low memory issues when a device is suspended.
1713 * Use kmalloc() rather than vmalloc() when we can.
1716 if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
1717 dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
1719 *param_flags |= DM_PARAMS_KMALLOC;
1724 noio_flag = memalloc_noio_save();
1725 dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL);
1726 memalloc_noio_restore(noio_flag);
1728 *param_flags |= DM_PARAMS_VMALLOC;
1732 if (secure_data && clear_user(user, param_kernel->data_size))
1737 if (copy_from_user(dmi, user, param_kernel->data_size))
1742 * Abort if something changed the ioctl data while it was being copied.
1744 if (dmi->data_size != param_kernel->data_size) {
1745 DMERR("rejecting ioctl: data size modified while processing parameters");
1749 /* Wipe the user buffer so we do not return it to userspace */
1750 if (secure_data && clear_user(user, param_kernel->data_size))
1757 free_params(dmi, param_kernel->data_size, *param_flags);
1762 static int validate_params(uint cmd, struct dm_ioctl *param)
1764 /* Always clear this flag */
1765 param->flags &= ~DM_BUFFER_FULL_FLAG;
1766 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1767 param->flags &= ~DM_SECURE_DATA_FLAG;
1768 param->flags &= ~DM_DATA_OUT_FLAG;
1770 /* Ignores parameters */
1771 if (cmd == DM_REMOVE_ALL_CMD ||
1772 cmd == DM_LIST_DEVICES_CMD ||
1773 cmd == DM_LIST_VERSIONS_CMD)
1776 if ((cmd == DM_DEV_CREATE_CMD)) {
1777 if (!*param->name) {
1778 DMWARN("name not supplied when creating device");
1781 } else if ((*param->uuid && *param->name)) {
1782 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1786 /* Ensure strings are terminated */
1787 param->name[DM_NAME_LEN - 1] = '\0';
1788 param->uuid[DM_UUID_LEN - 1] = '\0';
1793 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1799 struct dm_ioctl *uninitialized_var(param);
1801 size_t input_param_size;
1802 struct dm_ioctl param_kernel;
1804 /* only root can play with this */
1805 if (!capable(CAP_SYS_ADMIN))
1808 if (_IOC_TYPE(command) != DM_IOCTL)
1811 cmd = _IOC_NR(command);
1814 * Check the interface version passed in. This also
1815 * writes out the kernel's interface version.
1817 r = check_version(cmd, user);
1822 * Nothing more to do for the version command.
1824 if (cmd == DM_VERSION_CMD)
1827 fn = lookup_ioctl(cmd, &ioctl_flags);
1829 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1834 * Copy the parameters into kernel space.
1836 r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags);
1841 input_param_size = param->data_size;
1842 r = validate_params(cmd, param);
1846 param->data_size = sizeof(*param);
1847 r = fn(param, input_param_size);
1849 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1850 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1851 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1854 * Copy the results back to userland.
1856 if (!r && copy_to_user(user, param, param->data_size))
1860 free_params(param, input_param_size, param_flags);
1864 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1866 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1869 #ifdef CONFIG_COMPAT
1870 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1872 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1875 #define dm_compat_ctl_ioctl NULL
1878 static const struct file_operations _ctl_fops = {
1879 .open = nonseekable_open,
1880 .unlocked_ioctl = dm_ctl_ioctl,
1881 .compat_ioctl = dm_compat_ctl_ioctl,
1882 .owner = THIS_MODULE,
1883 .llseek = noop_llseek,
1886 static struct miscdevice _dm_misc = {
1887 .minor = MAPPER_CTRL_MINOR,
1889 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1893 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1894 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1897 * Create misc character device and link to DM_DIR/control.
1899 int __init dm_interface_init(void)
1907 r = misc_register(&_dm_misc);
1909 DMERR("misc_register failed for control device");
1914 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1915 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1920 void dm_interface_exit(void)
1922 if (misc_deregister(&_dm_misc) < 0)
1923 DMERR("misc_deregister failed for control device");
1929 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1930 * @md: Pointer to mapped_device
1931 * @name: Buffer (size DM_NAME_LEN) for name
1932 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1934 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1937 struct hash_cell *hc;
1942 mutex_lock(&dm_hash_cells_mutex);
1943 hc = dm_get_mdptr(md);
1944 if (!hc || hc->md != md) {
1950 strcpy(name, hc->name);
1952 strcpy(uuid, hc->uuid ? : "");
1955 mutex_unlock(&dm_hash_cells_mutex);