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/sched/mm.h>
14 #include <linux/init.h>
15 #include <linux/wait.h>
16 #include <linux/slab.h>
17 #include <linux/rbtree.h>
18 #include <linux/dm-ioctl.h>
19 #include <linux/hdreg.h>
20 #include <linux/compat.h>
21 #include <linux/nospec.h>
23 #include <linux/uaccess.h>
24 #include <linux/ima.h>
26 #define DM_MSG_PREFIX "ioctl"
27 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
31 * poll will wait until the global event number is greater than
34 volatile unsigned int global_event_nr;
37 /*-----------------------------------------------------------------
38 * The ioctl interface needs to be able to look up devices by
40 *---------------------------------------------------------------*/
42 struct rb_node name_node;
43 struct rb_node uuid_node;
49 struct mapped_device *md;
50 struct dm_table *new_map;
55 struct dm_target_versions *vers, *old_vers;
61 static struct rb_root name_rb_tree = RB_ROOT;
62 static struct rb_root uuid_rb_tree = RB_ROOT;
64 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
67 * Guards access to both hash tables.
69 static DECLARE_RWSEM(_hash_lock);
72 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
74 static DEFINE_MUTEX(dm_hash_cells_mutex);
76 static void dm_hash_exit(void)
78 dm_hash_remove_all(false, false, false);
81 /*-----------------------------------------------------------------
82 * Code for looking up a device by name
83 *---------------------------------------------------------------*/
84 static struct hash_cell *__get_name_cell(const char *str)
86 struct rb_node *n = name_rb_tree.rb_node;
89 struct hash_cell *hc = container_of(n, struct hash_cell, name_node);
90 int c = strcmp(hc->name, str);
95 n = c >= 0 ? n->rb_left : n->rb_right;
101 static struct hash_cell *__get_uuid_cell(const char *str)
103 struct rb_node *n = uuid_rb_tree.rb_node;
106 struct hash_cell *hc = container_of(n, struct hash_cell, uuid_node);
107 int c = strcmp(hc->uuid, str);
112 n = c >= 0 ? n->rb_left : n->rb_right;
118 static void __unlink_name(struct hash_cell *hc)
121 hc->name_set = false;
122 rb_erase(&hc->name_node, &name_rb_tree);
126 static void __unlink_uuid(struct hash_cell *hc)
129 hc->uuid_set = false;
130 rb_erase(&hc->uuid_node, &uuid_rb_tree);
134 static void __link_name(struct hash_cell *new_hc)
136 struct rb_node **n, *parent;
138 __unlink_name(new_hc);
140 new_hc->name_set = true;
142 n = &name_rb_tree.rb_node;
146 struct hash_cell *hc = container_of(*n, struct hash_cell, name_node);
147 int c = strcmp(hc->name, new_hc->name);
150 n = c >= 0 ? &hc->name_node.rb_left : &hc->name_node.rb_right;
153 rb_link_node(&new_hc->name_node, parent, n);
154 rb_insert_color(&new_hc->name_node, &name_rb_tree);
157 static void __link_uuid(struct hash_cell *new_hc)
159 struct rb_node **n, *parent;
161 __unlink_uuid(new_hc);
163 new_hc->uuid_set = true;
165 n = &uuid_rb_tree.rb_node;
169 struct hash_cell *hc = container_of(*n, struct hash_cell, uuid_node);
170 int c = strcmp(hc->uuid, new_hc->uuid);
173 n = c > 0 ? &hc->uuid_node.rb_left : &hc->uuid_node.rb_right;
176 rb_link_node(&new_hc->uuid_node, parent, n);
177 rb_insert_color(&new_hc->uuid_node, &uuid_rb_tree);
180 static struct hash_cell *__get_dev_cell(uint64_t dev)
182 struct mapped_device *md;
183 struct hash_cell *hc;
185 md = dm_get_md(huge_decode_dev(dev));
189 hc = dm_get_mdptr(md);
198 /*-----------------------------------------------------------------
199 * Inserting, removing and renaming a device.
200 *---------------------------------------------------------------*/
201 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
202 struct mapped_device *md)
204 struct hash_cell *hc;
206 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
210 hc->name = kstrdup(name, GFP_KERNEL);
220 hc->uuid = kstrdup(uuid, GFP_KERNEL);
228 hc->name_set = hc->uuid_set = false;
234 static void free_cell(struct hash_cell *hc)
244 * The kdev_t and uuid of a device can never change once it is
245 * initially inserted.
247 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
249 struct hash_cell *cell, *hc;
252 * Allocate the new cells.
254 cell = alloc_cell(name, uuid, md);
259 * Insert the cell into both hash tables.
261 down_write(&_hash_lock);
262 hc = __get_name_cell(name);
271 hc = __get_uuid_cell(uuid);
280 mutex_lock(&dm_hash_cells_mutex);
281 dm_set_mdptr(md, cell);
282 mutex_unlock(&dm_hash_cells_mutex);
283 up_write(&_hash_lock);
288 up_write(&_hash_lock);
293 static struct dm_table *__hash_remove(struct hash_cell *hc)
295 struct dm_table *table;
298 /* remove from the dev trees */
301 mutex_lock(&dm_hash_cells_mutex);
302 dm_set_mdptr(hc->md, NULL);
303 mutex_unlock(&dm_hash_cells_mutex);
305 table = dm_get_live_table(hc->md, &srcu_idx);
307 dm_table_event(table);
308 dm_put_live_table(hc->md, srcu_idx);
319 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
323 struct hash_cell *hc;
324 struct mapped_device *md;
330 down_write(&_hash_lock);
332 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
333 hc = container_of(n, struct hash_cell, name_node);
337 if (keep_open_devices &&
338 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
344 t = __hash_remove(hc);
346 up_write(&_hash_lock);
352 dm_ima_measure_on_device_remove(md, true);
354 if (likely(keep_open_devices))
357 dm_destroy_immediate(md);
360 * Some mapped devices may be using other mapped
361 * devices, so repeat until we make no further
362 * progress. If a new mapped device is created
363 * here it will also get removed.
368 up_write(&_hash_lock);
371 DMWARN("remove_all left %d open device(s)", dev_skipped);
375 * Set the uuid of a hash_cell that isn't already set.
377 static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
379 mutex_lock(&dm_hash_cells_mutex);
381 mutex_unlock(&dm_hash_cells_mutex);
387 * Changes the name of a hash_cell and returns the old name for
388 * the caller to free.
390 static char *__change_cell_name(struct hash_cell *hc, char *new_name)
395 * Rename and move the name cell.
400 mutex_lock(&dm_hash_cells_mutex);
402 mutex_unlock(&dm_hash_cells_mutex);
409 static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
412 char *new_data, *old_name = NULL;
413 struct hash_cell *hc;
414 struct dm_table *table;
415 struct mapped_device *md;
416 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
422 new_data = kstrdup(new, GFP_KERNEL);
424 return ERR_PTR(-ENOMEM);
426 down_write(&_hash_lock);
432 hc = __get_uuid_cell(new);
434 hc = __get_name_cell(new);
437 DMERR("Unable to change %s on mapped device %s to one that "
438 "already exists: %s",
439 change_uuid ? "uuid" : "name",
442 up_write(&_hash_lock);
444 return ERR_PTR(-EBUSY);
448 * Is there such a device as 'old' ?
450 hc = __get_name_cell(param->name);
452 DMERR("Unable to rename non-existent device, %s to %s%s",
453 param->name, change_uuid ? "uuid " : "", new);
454 up_write(&_hash_lock);
456 return ERR_PTR(-ENXIO);
460 * Does this device already have a uuid?
462 if (change_uuid && hc->uuid) {
463 DMERR("Unable to change uuid of mapped device %s to %s "
464 "because uuid is already set to %s",
465 param->name, new, hc->uuid);
467 up_write(&_hash_lock);
469 return ERR_PTR(-EINVAL);
473 __set_cell_uuid(hc, new_data);
475 old_name = __change_cell_name(hc, new_data);
478 * Wake up any dm event waiters.
480 table = dm_get_live_table(hc->md, &srcu_idx);
482 dm_table_event(table);
483 dm_put_live_table(hc->md, srcu_idx);
485 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr, false))
486 param->flags |= DM_UEVENT_GENERATED_FLAG;
490 dm_ima_measure_on_device_rename(md);
492 up_write(&_hash_lock);
498 void dm_deferred_remove(void)
500 dm_hash_remove_all(true, false, true);
503 /*-----------------------------------------------------------------
504 * Implementation of the ioctl commands
505 *---------------------------------------------------------------*/
507 * All the ioctl commands get dispatched to functions with this
510 typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
512 static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
514 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
515 param->data_size = 0;
520 * Round up the ptr to an 8-byte boundary.
523 static inline size_t align_val(size_t val)
525 return (val + ALIGN_MASK) & ~ALIGN_MASK;
527 static inline void *align_ptr(void *ptr)
529 return (void *)align_val((size_t)ptr);
533 * Retrieves the data payload buffer from an already allocated
536 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
539 param->data_start = align_ptr(param + 1) - (void *) param;
541 if (param->data_start < param_size)
542 *len = param_size - param->data_start;
546 return ((void *) param) + param->data_start;
549 static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid)
552 size_t val_len, pfx_len;
555 val_len = strlen(val);
556 pfx_len = strnlen(pfx_name, DM_NAME_LEN);
557 if (pfx_len > val_len)
559 if (memcmp(val, pfx_name, pfx_len))
562 val = hc->uuid ? hc->uuid : "";
563 val_len = strlen(val);
564 pfx_len = strnlen(pfx_uuid, DM_UUID_LEN);
565 if (pfx_len > val_len)
567 if (memcmp(val, pfx_uuid, pfx_len))
573 static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
576 struct hash_cell *hc;
577 size_t len, needed = 0;
578 struct gendisk *disk;
579 struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
582 down_write(&_hash_lock);
585 * Loop through all the devices working out how much
588 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
589 hc = container_of(n, struct hash_cell, name_node);
590 if (!filter_device(hc, param->name, param->uuid))
592 needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
593 needed += align_val(sizeof(uint32_t) * 2);
594 if (param->flags & DM_UUID_FLAG && hc->uuid)
595 needed += align_val(strlen(hc->uuid) + 1);
599 * Grab our output buffer.
601 nl = orig_nl = get_result_buffer(param, param_size, &len);
602 if (len < needed || len < sizeof(nl->dev)) {
603 param->flags |= DM_BUFFER_FULL_FLAG;
606 param->data_size = param->data_start + needed;
608 nl->dev = 0; /* Flags no data */
611 * Now loop through filling out the names.
613 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
615 hc = container_of(n, struct hash_cell, name_node);
616 if (!filter_device(hc, param->name, param->uuid))
619 old_nl->next = (uint32_t) ((void *) nl -
621 disk = dm_disk(hc->md);
622 nl->dev = huge_encode_dev(disk_devt(disk));
624 strcpy(nl->name, hc->name);
627 event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
628 event_nr[0] = dm_get_event_nr(hc->md);
630 uuid_ptr = align_ptr(event_nr + 2);
631 if (param->flags & DM_UUID_FLAG) {
633 event_nr[1] |= DM_NAME_LIST_FLAG_HAS_UUID;
634 strcpy(uuid_ptr, hc->uuid);
635 uuid_ptr = align_ptr(uuid_ptr + strlen(hc->uuid) + 1);
637 event_nr[1] |= DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID;
643 * If mismatch happens, security may be compromised due to buffer
644 * overflow, so it's better to crash.
646 BUG_ON((char *)nl - (char *)orig_nl != needed);
649 up_write(&_hash_lock);
653 static void list_version_get_needed(struct target_type *tt, void *needed_param)
655 size_t *needed = needed_param;
657 *needed += sizeof(struct dm_target_versions);
658 *needed += strlen(tt->name) + 1;
659 *needed += ALIGN_MASK;
662 static void list_version_get_info(struct target_type *tt, void *param)
664 struct vers_iter *info = param;
666 /* Check space - it might have changed since the first iteration */
667 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
670 info->flags = DM_BUFFER_FULL_FLAG;
675 info->old_vers->next = (uint32_t) ((void *)info->vers -
676 (void *)info->old_vers);
677 info->vers->version[0] = tt->version[0];
678 info->vers->version[1] = tt->version[1];
679 info->vers->version[2] = tt->version[2];
680 info->vers->next = 0;
681 strcpy(info->vers->name, tt->name);
683 info->old_vers = info->vers;
684 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
687 static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
689 size_t len, needed = 0;
690 struct dm_target_versions *vers;
691 struct vers_iter iter_info;
692 struct target_type *tt = NULL;
695 tt = dm_get_target_type(name);
701 * Loop through all the devices working out how much
705 dm_target_iterate(list_version_get_needed, &needed);
707 list_version_get_needed(tt, &needed);
710 * Grab our output buffer.
712 vers = get_result_buffer(param, param_size, &len);
714 param->flags |= DM_BUFFER_FULL_FLAG;
717 param->data_size = param->data_start + needed;
719 iter_info.param_size = param_size;
720 iter_info.old_vers = NULL;
721 iter_info.vers = vers;
723 iter_info.end = (char *)vers + needed;
726 * Now loop through filling out the names & versions.
729 dm_target_iterate(list_version_get_info, &iter_info);
731 list_version_get_info(tt, &iter_info);
732 param->flags |= iter_info.flags;
736 dm_put_target_type(tt);
740 static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
742 return __list_versions(param, param_size, NULL);
745 static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
747 return __list_versions(param, param_size, param->name);
750 static int check_name(const char *name)
752 if (strchr(name, '/')) {
753 DMERR("invalid device name");
761 * On successful return, the caller must not attempt to acquire
762 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
763 * waits for this dm_put_live_table and could be called under this lock.
765 static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
767 struct hash_cell *hc;
768 struct dm_table *table = NULL;
770 /* increment rcu count, we don't care about the table pointer */
771 dm_get_live_table(md, srcu_idx);
773 down_read(&_hash_lock);
774 hc = dm_get_mdptr(md);
775 if (!hc || hc->md != md) {
776 DMERR("device has been removed from the dev hash table.");
783 up_read(&_hash_lock);
788 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
789 struct dm_ioctl *param,
792 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
793 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
797 * Fills in a dm_ioctl structure, ready for sending back to
800 static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
802 struct gendisk *disk = dm_disk(md);
803 struct dm_table *table;
806 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
807 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
809 if (dm_suspended_md(md))
810 param->flags |= DM_SUSPEND_FLAG;
812 if (dm_suspended_internally_md(md))
813 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
815 if (dm_test_deferred_remove_flag(md))
816 param->flags |= DM_DEFERRED_REMOVE;
818 param->dev = huge_encode_dev(disk_devt(disk));
821 * Yes, this will be out of date by the time it gets back
822 * to userland, but it is still very useful for
825 param->open_count = dm_open_count(md);
827 param->event_nr = dm_get_event_nr(md);
828 param->target_count = 0;
830 table = dm_get_live_table(md, &srcu_idx);
832 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
833 if (get_disk_ro(disk))
834 param->flags |= DM_READONLY_FLAG;
835 param->target_count = table->num_targets;
838 param->flags |= DM_ACTIVE_PRESENT_FLAG;
840 dm_put_live_table(md, srcu_idx);
842 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
844 table = dm_get_inactive_table(md, &srcu_idx);
846 if (!(dm_table_get_mode(table) & FMODE_WRITE))
847 param->flags |= DM_READONLY_FLAG;
848 param->target_count = table->num_targets;
850 dm_put_live_table(md, srcu_idx);
854 static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
856 int r, m = DM_ANY_MINOR;
857 struct mapped_device *md;
859 r = check_name(param->name);
863 if (param->flags & DM_PERSISTENT_DEV_FLAG)
864 m = MINOR(huge_decode_dev(param->dev));
866 r = dm_create(m, &md);
870 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
877 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
879 __dev_status(md, param);
887 * Always use UUID for lookups if it's present, otherwise use name or dev.
889 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
891 struct hash_cell *hc = NULL;
894 if (*param->name || param->dev) {
895 DMERR("Invalid ioctl structure: uuid %s, name %s, dev %llx",
896 param->uuid, param->name, (unsigned long long)param->dev);
900 hc = __get_uuid_cell(param->uuid);
903 } else if (*param->name) {
905 DMERR("Invalid ioctl structure: name %s, dev %llx",
906 param->name, (unsigned long long)param->dev);
910 hc = __get_name_cell(param->name);
913 } else if (param->dev) {
914 hc = __get_dev_cell(param->dev);
921 * Sneakily write in both the name and the uuid
922 * while we have the cell.
924 strlcpy(param->name, hc->name, sizeof(param->name));
926 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
928 param->uuid[0] = '\0';
931 param->flags |= DM_INACTIVE_PRESENT_FLAG;
933 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
938 static struct mapped_device *find_device(struct dm_ioctl *param)
940 struct hash_cell *hc;
941 struct mapped_device *md = NULL;
943 down_read(&_hash_lock);
944 hc = __find_device_hash_cell(param);
947 up_read(&_hash_lock);
952 static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
954 struct hash_cell *hc;
955 struct mapped_device *md;
959 down_write(&_hash_lock);
960 hc = __find_device_hash_cell(param);
963 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
964 up_write(&_hash_lock);
971 * Ensure the device is not open and nothing further can open it.
973 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
975 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
976 up_write(&_hash_lock);
980 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
981 up_write(&_hash_lock);
986 t = __hash_remove(hc);
987 up_write(&_hash_lock);
994 param->flags &= ~DM_DEFERRED_REMOVE;
996 dm_ima_measure_on_device_remove(md, false);
998 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr, false))
999 param->flags |= DM_UEVENT_GENERATED_FLAG;
1007 * Check a string doesn't overrun the chunk of
1008 * memory we copied from userland.
1010 static int invalid_str(char *str, void *end)
1012 while ((void *) str < end)
1019 static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
1022 char *new_data = (char *) param + param->data_start;
1023 struct mapped_device *md;
1024 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
1026 if (new_data < param->data ||
1027 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
1028 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
1029 DMERR("Invalid new mapped device name or uuid string supplied.");
1034 r = check_name(new_data);
1039 md = dm_hash_rename(param, new_data);
1043 __dev_status(md, param);
1049 static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
1052 struct mapped_device *md;
1053 struct hd_geometry geometry;
1054 unsigned long indata[4];
1055 char *geostr = (char *) param + param->data_start;
1058 md = find_device(param);
1062 if (geostr < param->data ||
1063 invalid_str(geostr, (void *) param + param_size)) {
1064 DMERR("Invalid geometry supplied.");
1068 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
1069 indata + 1, indata + 2, indata + 3, &dummy);
1072 DMERR("Unable to interpret geometry settings.");
1076 if (indata[0] > 65535 || indata[1] > 255 ||
1077 indata[2] > 255 || indata[3] > ULONG_MAX) {
1078 DMERR("Geometry exceeds range limits.");
1082 geometry.cylinders = indata[0];
1083 geometry.heads = indata[1];
1084 geometry.sectors = indata[2];
1085 geometry.start = indata[3];
1087 r = dm_set_geometry(md, &geometry);
1089 param->data_size = 0;
1096 static int do_suspend(struct dm_ioctl *param)
1099 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1100 struct mapped_device *md;
1102 md = find_device(param);
1106 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1107 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1108 if (param->flags & DM_NOFLUSH_FLAG)
1109 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1111 if (!dm_suspended_md(md)) {
1112 r = dm_suspend(md, suspend_flags);
1117 __dev_status(md, param);
1125 static int do_resume(struct dm_ioctl *param)
1128 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1129 struct hash_cell *hc;
1130 struct mapped_device *md;
1131 struct dm_table *new_map, *old_map = NULL;
1132 bool need_resize_uevent = false;
1134 down_write(&_hash_lock);
1136 hc = __find_device_hash_cell(param);
1138 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1139 up_write(&_hash_lock);
1145 new_map = hc->new_map;
1147 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1149 up_write(&_hash_lock);
1151 /* Do we need to load a new map ? */
1153 sector_t old_size, new_size;
1155 /* Suspend if it isn't already suspended */
1156 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1157 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1158 if (param->flags & DM_NOFLUSH_FLAG)
1159 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1160 if (!dm_suspended_md(md))
1161 dm_suspend(md, suspend_flags);
1163 old_size = dm_get_size(md);
1164 old_map = dm_swap_table(md, new_map);
1165 if (IS_ERR(old_map)) {
1167 dm_table_destroy(new_map);
1169 return PTR_ERR(old_map);
1171 new_size = dm_get_size(md);
1172 if (old_size && new_size && old_size != new_size)
1173 need_resize_uevent = true;
1175 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1176 set_disk_ro(dm_disk(md), 0);
1178 set_disk_ro(dm_disk(md), 1);
1181 if (dm_suspended_md(md)) {
1184 dm_ima_measure_on_device_resume(md, new_map ? true : false);
1186 if (!dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr, need_resize_uevent))
1187 param->flags |= DM_UEVENT_GENERATED_FLAG;
1192 * Since dm_swap_table synchronizes RCU, nobody should be in
1193 * read-side critical section already.
1196 dm_table_destroy(old_map);
1199 __dev_status(md, param);
1206 * Set or unset the suspension state of a device.
1207 * If the device already is in the requested state we just return its status.
1209 static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1211 if (param->flags & DM_SUSPEND_FLAG)
1212 return do_suspend(param);
1214 return do_resume(param);
1218 * Copies device info back to user space, used by
1219 * the create and info ioctls.
1221 static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1223 struct mapped_device *md;
1225 md = find_device(param);
1229 __dev_status(md, param);
1236 * Build up the status struct for each target
1238 static void retrieve_status(struct dm_table *table,
1239 struct dm_ioctl *param, size_t param_size)
1241 unsigned int i, num_targets;
1242 struct dm_target_spec *spec;
1243 char *outbuf, *outptr;
1245 size_t remaining, len, used = 0;
1246 unsigned int status_flags = 0;
1248 outptr = outbuf = get_result_buffer(param, param_size, &len);
1250 if (param->flags & DM_STATUS_TABLE_FLAG)
1251 type = STATUSTYPE_TABLE;
1252 else if (param->flags & DM_IMA_MEASUREMENT_FLAG)
1253 type = STATUSTYPE_IMA;
1255 type = STATUSTYPE_INFO;
1257 /* Get all the target info */
1258 num_targets = table->num_targets;
1259 for (i = 0; i < num_targets; i++) {
1260 struct dm_target *ti = dm_table_get_target(table, i);
1263 remaining = len - (outptr - outbuf);
1264 if (remaining <= sizeof(struct dm_target_spec)) {
1265 param->flags |= DM_BUFFER_FULL_FLAG;
1269 spec = (struct dm_target_spec *) outptr;
1272 spec->sector_start = ti->begin;
1273 spec->length = ti->len;
1274 strncpy(spec->target_type, ti->type->name,
1275 sizeof(spec->target_type) - 1);
1277 outptr += sizeof(struct dm_target_spec);
1278 remaining = len - (outptr - outbuf);
1279 if (remaining <= 0) {
1280 param->flags |= DM_BUFFER_FULL_FLAG;
1284 /* Get the status/table string from the target driver */
1285 if (ti->type->status) {
1286 if (param->flags & DM_NOFLUSH_FLAG)
1287 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1288 ti->type->status(ti, type, status_flags, outptr, remaining);
1292 l = strlen(outptr) + 1;
1293 if (l == remaining) {
1294 param->flags |= DM_BUFFER_FULL_FLAG;
1299 used = param->data_start + (outptr - outbuf);
1301 outptr = align_ptr(outptr);
1302 spec->next = outptr - outbuf;
1306 param->data_size = used;
1308 param->target_count = num_targets;
1312 * Wait for a device to report an event
1314 static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1317 struct mapped_device *md;
1318 struct dm_table *table;
1321 md = find_device(param);
1326 * Wait for a notification event
1328 if (dm_wait_event(md, param->event_nr)) {
1334 * The userland program is going to want to know what
1335 * changed to trigger the event, so we may as well tell
1336 * him and save an ioctl.
1338 __dev_status(md, param);
1340 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1342 retrieve_status(table, param, param_size);
1343 dm_put_live_table(md, srcu_idx);
1352 * Remember the global event number and make it possible to poll
1353 * for further events.
1355 static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1357 struct dm_file *priv = filp->private_data;
1359 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1364 static inline fmode_t get_mode(struct dm_ioctl *param)
1366 fmode_t mode = FMODE_READ | FMODE_WRITE;
1368 if (param->flags & DM_READONLY_FLAG)
1374 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1375 struct dm_target_spec **spec, char **target_params)
1377 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1378 *target_params = (char *) (*spec + 1);
1380 if (*spec < (last + 1))
1383 return invalid_str(*target_params, end);
1386 static int populate_table(struct dm_table *table,
1387 struct dm_ioctl *param, size_t param_size)
1391 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1392 uint32_t next = param->data_start;
1393 void *end = (void *) param + param_size;
1394 char *target_params;
1396 if (!param->target_count) {
1397 DMERR("populate_table: no targets specified");
1401 for (i = 0; i < param->target_count; i++) {
1403 r = next_target(spec, next, end, &spec, &target_params);
1405 DMERR("unable to find target");
1409 r = dm_table_add_target(table, spec->target_type,
1410 (sector_t) spec->sector_start,
1411 (sector_t) spec->length,
1414 DMERR("error adding target to table");
1421 return dm_table_complete(table);
1424 static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1427 (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1433 static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1436 struct hash_cell *hc;
1437 struct dm_table *t, *old_map = NULL;
1438 struct mapped_device *md;
1439 struct target_type *immutable_target_type;
1441 md = find_device(param);
1445 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1449 /* Protect md->type and md->queue against concurrent table loads. */
1450 dm_lock_md_type(md);
1451 r = populate_table(t, param, param_size);
1453 goto err_unlock_md_type;
1455 dm_ima_measure_on_table_load(t, STATUSTYPE_IMA);
1457 immutable_target_type = dm_get_immutable_target_type(md);
1458 if (immutable_target_type &&
1459 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1460 !dm_table_get_wildcard_target(t)) {
1461 DMERR("can't replace immutable target type %s",
1462 immutable_target_type->name);
1464 goto err_unlock_md_type;
1467 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1468 /* setup md->queue to reflect md's type (may block) */
1469 r = dm_setup_md_queue(md, t);
1471 DMERR("unable to set up device queue for new table.");
1472 goto err_unlock_md_type;
1474 } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
1475 DMERR("can't change device type (old=%u vs new=%u) after initial table load.",
1476 dm_get_md_type(md), dm_table_get_type(t));
1478 goto err_unlock_md_type;
1481 dm_unlock_md_type(md);
1483 /* stage inactive table */
1484 down_write(&_hash_lock);
1485 hc = dm_get_mdptr(md);
1486 if (!hc || hc->md != md) {
1487 DMERR("device has been removed from the dev hash table.");
1488 up_write(&_hash_lock);
1490 goto err_destroy_table;
1494 old_map = hc->new_map;
1496 up_write(&_hash_lock);
1498 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1499 __dev_status(md, param);
1503 dm_table_destroy(old_map);
1511 dm_unlock_md_type(md);
1513 dm_table_destroy(t);
1520 static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1522 struct hash_cell *hc;
1523 struct mapped_device *md;
1524 struct dm_table *old_map = NULL;
1525 bool has_new_map = false;
1527 down_write(&_hash_lock);
1529 hc = __find_device_hash_cell(param);
1531 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1532 up_write(&_hash_lock);
1537 old_map = hc->new_map;
1542 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1544 __dev_status(hc->md, param);
1546 up_write(&_hash_lock);
1549 dm_table_destroy(old_map);
1551 dm_ima_measure_on_table_clear(md, has_new_map);
1558 * Retrieves a list of devices used by a particular dm device.
1560 static void retrieve_deps(struct dm_table *table,
1561 struct dm_ioctl *param, size_t param_size)
1563 unsigned int count = 0;
1564 struct list_head *tmp;
1566 struct dm_dev_internal *dd;
1567 struct dm_target_deps *deps;
1569 deps = get_result_buffer(param, param_size, &len);
1572 * Count the devices.
1574 list_for_each (tmp, dm_table_get_devices(table))
1578 * Check we have enough space.
1580 needed = struct_size(deps, dev, count);
1582 param->flags |= DM_BUFFER_FULL_FLAG;
1587 * Fill in the devices.
1589 deps->count = count;
1591 list_for_each_entry (dd, dm_table_get_devices(table), list)
1592 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1594 param->data_size = param->data_start + needed;
1597 static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1599 struct mapped_device *md;
1600 struct dm_table *table;
1603 md = find_device(param);
1607 __dev_status(md, param);
1609 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1611 retrieve_deps(table, param, param_size);
1612 dm_put_live_table(md, srcu_idx);
1620 * Return the status of a device as a text string for each
1623 static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1625 struct mapped_device *md;
1626 struct dm_table *table;
1629 md = find_device(param);
1633 __dev_status(md, param);
1635 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1637 retrieve_status(table, param, param_size);
1638 dm_put_live_table(md, srcu_idx);
1646 * Process device-mapper dependent messages. Messages prefixed with '@'
1647 * are processed by the DM core. All others are delivered to the target.
1648 * Returns a number <= 1 if message was processed by device mapper.
1649 * Returns 2 if message should be delivered to the target.
1651 static int message_for_md(struct mapped_device *md, unsigned int argc, char **argv,
1652 char *result, unsigned int maxlen)
1657 return 2; /* no '@' prefix, deliver to target */
1659 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1661 DMERR("Invalid arguments for @cancel_deferred_remove");
1664 return dm_cancel_deferred_remove(md);
1667 r = dm_stats_message(md, argc, argv, result, maxlen);
1671 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1676 * Pass a message to the target that's at the supplied device offset.
1678 static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1682 struct mapped_device *md;
1683 struct dm_table *table;
1684 struct dm_target *ti;
1685 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1687 char *result = get_result_buffer(param, param_size, &maxlen);
1690 md = find_device(param);
1694 if (tmsg < (struct dm_target_msg *) param->data ||
1695 invalid_str(tmsg->message, (void *) param + param_size)) {
1696 DMERR("Invalid target message parameters.");
1701 r = dm_split_args(&argc, &argv, tmsg->message);
1703 DMERR("Failed to split target message parameters");
1708 DMERR("Empty message received.");
1713 r = message_for_md(md, argc, argv, result, maxlen);
1717 table = dm_get_live_table(md, &srcu_idx);
1721 if (dm_deleting_md(md)) {
1726 ti = dm_table_find_target(table, tmsg->sector);
1728 DMERR("Target message sector outside device.");
1730 } else if (ti->type->message)
1731 r = ti->type->message(ti, argc, argv, result, maxlen);
1733 DMERR("Target type does not support messages");
1738 dm_put_live_table(md, srcu_idx);
1743 __dev_status(md, param);
1746 param->flags |= DM_DATA_OUT_FLAG;
1747 if (dm_message_test_buffer_overflow(result, maxlen))
1748 param->flags |= DM_BUFFER_FULL_FLAG;
1750 param->data_size = param->data_start + strlen(result) + 1;
1759 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1760 * followed by a data buffer. This flag is set if the second part,
1761 * which has a variable size, is not used by the function processing
1764 #define IOCTL_FLAGS_NO_PARAMS 1
1765 #define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
1767 /*-----------------------------------------------------------------
1768 * Implementation of open/close/ioctl on the special char
1770 *---------------------------------------------------------------*/
1771 static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1773 static const struct {
1778 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1779 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
1780 {DM_LIST_DEVICES_CMD, 0, list_devices},
1782 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
1783 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
1784 {DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
1785 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1786 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1787 {DM_DEV_WAIT_CMD, 0, dev_wait},
1789 {DM_TABLE_LOAD_CMD, 0, table_load},
1790 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1791 {DM_TABLE_DEPS_CMD, 0, table_deps},
1792 {DM_TABLE_STATUS_CMD, 0, table_status},
1794 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1796 {DM_TARGET_MSG_CMD, 0, target_message},
1797 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
1798 {DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
1799 {DM_GET_TARGET_VERSION, 0, get_target_version},
1802 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1805 cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
1806 *ioctl_flags = _ioctls[cmd].flags;
1807 return _ioctls[cmd].fn;
1811 * As well as checking the version compatibility this always
1812 * copies the kernel interface version out.
1814 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1816 uint32_t version[3];
1819 if (copy_from_user(version, user->version, sizeof(version)))
1822 if ((DM_VERSION_MAJOR != version[0]) ||
1823 (DM_VERSION_MINOR < version[1])) {
1824 DMERR("ioctl interface mismatch: "
1825 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1826 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1827 DM_VERSION_PATCHLEVEL,
1828 version[0], version[1], version[2], cmd);
1833 * Fill in the kernel version.
1835 version[0] = DM_VERSION_MAJOR;
1836 version[1] = DM_VERSION_MINOR;
1837 version[2] = DM_VERSION_PATCHLEVEL;
1838 if (copy_to_user(user->version, version, sizeof(version)))
1844 #define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
1845 #define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1847 static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1849 if (param_flags & DM_WIPE_BUFFER)
1850 memset(param, 0, param_size);
1852 if (param_flags & DM_PARAMS_MALLOC)
1856 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1857 int ioctl_flags, struct dm_ioctl **param, int *param_flags)
1859 struct dm_ioctl *dmi;
1861 const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
1862 unsigned int noio_flag;
1864 if (copy_from_user(param_kernel, user, minimum_data_size))
1867 if (param_kernel->data_size < minimum_data_size) {
1868 DMERR("Invalid data size in the ioctl structure: %u",
1869 param_kernel->data_size);
1873 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1875 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1877 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1879 dmi->data_size = minimum_data_size;
1884 * Use __GFP_HIGH to avoid low memory issues when a device is
1885 * suspended and the ioctl is needed to resume it.
1886 * Use kmalloc() rather than vmalloc() when we can.
1889 noio_flag = memalloc_noio_save();
1890 dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);
1891 memalloc_noio_restore(noio_flag);
1894 if (secure_data && clear_user(user, param_kernel->data_size))
1899 *param_flags |= DM_PARAMS_MALLOC;
1901 /* Copy from param_kernel (which was already copied from user) */
1902 memcpy(dmi, param_kernel, minimum_data_size);
1904 if (copy_from_user(&dmi->data, (char __user *)user + minimum_data_size,
1905 param_kernel->data_size - minimum_data_size))
1908 /* Wipe the user buffer so we do not return it to userspace */
1909 if (secure_data && clear_user(user, param_kernel->data_size))
1916 free_params(dmi, param_kernel->data_size, *param_flags);
1921 static int validate_params(uint cmd, struct dm_ioctl *param)
1923 /* Always clear this flag */
1924 param->flags &= ~DM_BUFFER_FULL_FLAG;
1925 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1926 param->flags &= ~DM_SECURE_DATA_FLAG;
1927 param->flags &= ~DM_DATA_OUT_FLAG;
1929 /* Ignores parameters */
1930 if (cmd == DM_REMOVE_ALL_CMD ||
1931 cmd == DM_LIST_DEVICES_CMD ||
1932 cmd == DM_LIST_VERSIONS_CMD)
1935 if (cmd == DM_DEV_CREATE_CMD) {
1936 if (!*param->name) {
1937 DMERR("name not supplied when creating device");
1940 } else if (*param->uuid && *param->name) {
1941 DMERR("only supply one of name or uuid, cmd(%u)", cmd);
1945 /* Ensure strings are terminated */
1946 param->name[DM_NAME_LEN - 1] = '\0';
1947 param->uuid[DM_UUID_LEN - 1] = '\0';
1952 static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
1958 struct dm_ioctl *param;
1960 size_t input_param_size;
1961 struct dm_ioctl param_kernel;
1963 /* only root can play with this */
1964 if (!capable(CAP_SYS_ADMIN))
1967 if (_IOC_TYPE(command) != DM_IOCTL)
1970 cmd = _IOC_NR(command);
1973 * Check the interface version passed in. This also
1974 * writes out the kernel's interface version.
1976 r = check_version(cmd, user);
1981 * Nothing more to do for the version command.
1983 if (cmd == DM_VERSION_CMD)
1986 fn = lookup_ioctl(cmd, &ioctl_flags);
1988 DMERR("dm_ctl_ioctl: unknown command 0x%x", command);
1993 * Copy the parameters into kernel space.
1995 r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags);
2000 input_param_size = param->data_size;
2001 r = validate_params(cmd, param);
2005 param->data_size = offsetof(struct dm_ioctl, data);
2006 r = fn(file, param, input_param_size);
2008 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
2009 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
2010 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
2012 if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
2013 dm_issue_global_event();
2016 * Copy the results back to userland.
2018 if (!r && copy_to_user(user, param, param->data_size))
2022 free_params(param, input_param_size, param_flags);
2026 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
2028 return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
2031 #ifdef CONFIG_COMPAT
2032 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
2034 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
2037 #define dm_compat_ctl_ioctl NULL
2040 static int dm_open(struct inode *inode, struct file *filp)
2043 struct dm_file *priv;
2045 r = nonseekable_open(inode, filp);
2049 priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
2053 priv->global_event_nr = atomic_read(&dm_global_event_nr);
2058 static int dm_release(struct inode *inode, struct file *filp)
2060 kfree(filp->private_data);
2064 static __poll_t dm_poll(struct file *filp, poll_table *wait)
2066 struct dm_file *priv = filp->private_data;
2069 poll_wait(filp, &dm_global_eventq, wait);
2071 if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
2077 static const struct file_operations _ctl_fops = {
2079 .release = dm_release,
2081 .unlocked_ioctl = dm_ctl_ioctl,
2082 .compat_ioctl = dm_compat_ctl_ioctl,
2083 .owner = THIS_MODULE,
2084 .llseek = noop_llseek,
2087 static struct miscdevice _dm_misc = {
2088 .minor = MAPPER_CTRL_MINOR,
2090 .nodename = DM_DIR "/" DM_CONTROL_NODE,
2094 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
2095 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
2098 * Create misc character device and link to DM_DIR/control.
2100 int __init dm_interface_init(void)
2104 r = misc_register(&_dm_misc);
2106 DMERR("misc_register failed for control device");
2110 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
2111 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
2116 void dm_interface_exit(void)
2118 misc_deregister(&_dm_misc);
2123 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
2124 * @md: Pointer to mapped_device
2125 * @name: Buffer (size DM_NAME_LEN) for name
2126 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2128 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2131 struct hash_cell *hc;
2136 mutex_lock(&dm_hash_cells_mutex);
2137 hc = dm_get_mdptr(md);
2138 if (!hc || hc->md != md) {
2144 strcpy(name, hc->name);
2146 strcpy(uuid, hc->uuid ? : "");
2149 mutex_unlock(&dm_hash_cells_mutex);
2153 EXPORT_SYMBOL_GPL(dm_copy_name_and_uuid);
2156 * dm_early_create - create a mapped device in early boot.
2158 * @dmi: Contains main information of the device mapping to be created.
2159 * @spec_array: array of pointers to struct dm_target_spec. Describes the
2160 * mapping table of the device.
2161 * @target_params_array: array of strings with the parameters to a specific
2164 * Instead of having the struct dm_target_spec and the parameters for every
2165 * target embedded at the end of struct dm_ioctl (as performed in a normal
2166 * ioctl), pass them as arguments, so the caller doesn't need to serialize them.
2167 * The size of the spec_array and target_params_array is given by
2168 * @dmi->target_count.
2169 * This function is supposed to be called in early boot, so locking mechanisms
2170 * to protect against concurrent loads are not required.
2172 int __init dm_early_create(struct dm_ioctl *dmi,
2173 struct dm_target_spec **spec_array,
2174 char **target_params_array)
2176 int r, m = DM_ANY_MINOR;
2177 struct dm_table *t, *old_map;
2178 struct mapped_device *md;
2181 if (!dmi->target_count)
2184 r = check_name(dmi->name);
2188 if (dmi->flags & DM_PERSISTENT_DEV_FLAG)
2189 m = MINOR(huge_decode_dev(dmi->dev));
2191 /* alloc dm device */
2192 r = dm_create(m, &md);
2197 r = dm_hash_insert(dmi->name, *dmi->uuid ? dmi->uuid : NULL, md);
2199 goto err_destroy_dm;
2202 r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md);
2204 goto err_hash_remove;
2207 for (i = 0; i < dmi->target_count; i++) {
2208 r = dm_table_add_target(t, spec_array[i]->target_type,
2209 (sector_t) spec_array[i]->sector_start,
2210 (sector_t) spec_array[i]->length,
2211 target_params_array[i]);
2213 DMERR("error adding target to table");
2214 goto err_destroy_table;
2219 r = dm_table_complete(t);
2221 goto err_destroy_table;
2223 /* setup md->queue to reflect md's type (may block) */
2224 r = dm_setup_md_queue(md, t);
2226 DMERR("unable to set up device queue for new table.");
2227 goto err_destroy_table;
2232 old_map = dm_swap_table(md, t);
2233 if (IS_ERR(old_map)) {
2234 r = PTR_ERR(old_map);
2235 goto err_destroy_table;
2237 set_disk_ro(dm_disk(md), !!(dmi->flags & DM_READONLY_FLAG));
2242 goto err_destroy_table;
2244 DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name);
2249 dm_table_destroy(t);
2251 (void) __hash_remove(__get_name_cell(dmi->name));
2252 /* release reference from __get_name_cell */