1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
4 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
6 * This file is released under the GPL.
11 #include <linux/module.h>
12 #include <linux/vmalloc.h>
13 #include <linux/miscdevice.h>
14 #include <linux/sched/mm.h>
15 #include <linux/init.h>
16 #include <linux/wait.h>
17 #include <linux/slab.h>
18 #include <linux/rbtree.h>
19 #include <linux/dm-ioctl.h>
20 #include <linux/hdreg.h>
21 #include <linux/compat.h>
22 #include <linux/nospec.h>
24 #include <linux/uaccess.h>
25 #include <linux/ima.h>
27 #define DM_MSG_PREFIX "ioctl"
28 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
32 * poll will wait until the global event number is greater than
35 volatile unsigned int global_event_nr;
39 *---------------------------------------------------------------
40 * The ioctl interface needs to be able to look up devices by
42 *---------------------------------------------------------------
45 struct rb_node name_node;
46 struct rb_node uuid_node;
52 struct mapped_device *md;
53 struct dm_table *new_map;
58 struct dm_target_versions *vers, *old_vers;
64 static struct rb_root name_rb_tree = RB_ROOT;
65 static struct rb_root uuid_rb_tree = RB_ROOT;
67 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
70 * Guards access to both hash tables.
72 static DECLARE_RWSEM(_hash_lock);
75 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
77 static DEFINE_MUTEX(dm_hash_cells_mutex);
79 static void dm_hash_exit(void)
81 dm_hash_remove_all(false, false, false);
85 *---------------------------------------------------------------
86 * Code for looking up a device by name
87 *---------------------------------------------------------------
89 static struct hash_cell *__get_name_cell(const char *str)
91 struct rb_node *n = name_rb_tree.rb_node;
94 struct hash_cell *hc = container_of(n, struct hash_cell, name_node);
97 c = strcmp(hc->name, str);
102 n = c >= 0 ? n->rb_left : n->rb_right;
108 static struct hash_cell *__get_uuid_cell(const char *str)
110 struct rb_node *n = uuid_rb_tree.rb_node;
113 struct hash_cell *hc = container_of(n, struct hash_cell, uuid_node);
116 c = strcmp(hc->uuid, str);
121 n = c >= 0 ? n->rb_left : n->rb_right;
127 static void __unlink_name(struct hash_cell *hc)
130 hc->name_set = false;
131 rb_erase(&hc->name_node, &name_rb_tree);
135 static void __unlink_uuid(struct hash_cell *hc)
138 hc->uuid_set = false;
139 rb_erase(&hc->uuid_node, &uuid_rb_tree);
143 static void __link_name(struct hash_cell *new_hc)
145 struct rb_node **n, *parent;
147 __unlink_name(new_hc);
149 new_hc->name_set = true;
151 n = &name_rb_tree.rb_node;
155 struct hash_cell *hc = container_of(*n, struct hash_cell, name_node);
158 c = strcmp(hc->name, new_hc->name);
161 n = c >= 0 ? &hc->name_node.rb_left : &hc->name_node.rb_right;
164 rb_link_node(&new_hc->name_node, parent, n);
165 rb_insert_color(&new_hc->name_node, &name_rb_tree);
168 static void __link_uuid(struct hash_cell *new_hc)
170 struct rb_node **n, *parent;
172 __unlink_uuid(new_hc);
174 new_hc->uuid_set = true;
176 n = &uuid_rb_tree.rb_node;
180 struct hash_cell *hc = container_of(*n, struct hash_cell, uuid_node);
183 c = strcmp(hc->uuid, new_hc->uuid);
186 n = c > 0 ? &hc->uuid_node.rb_left : &hc->uuid_node.rb_right;
189 rb_link_node(&new_hc->uuid_node, parent, n);
190 rb_insert_color(&new_hc->uuid_node, &uuid_rb_tree);
193 static struct hash_cell *__get_dev_cell(uint64_t dev)
195 struct mapped_device *md;
196 struct hash_cell *hc;
198 md = dm_get_md(huge_decode_dev(dev));
202 hc = dm_get_mdptr(md);
212 *---------------------------------------------------------------
213 * Inserting, removing and renaming a device.
214 *---------------------------------------------------------------
216 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
217 struct mapped_device *md)
219 struct hash_cell *hc;
221 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
225 hc->name = kstrdup(name, GFP_KERNEL);
235 hc->uuid = kstrdup(uuid, GFP_KERNEL);
243 hc->name_set = hc->uuid_set = false;
249 static void free_cell(struct hash_cell *hc)
259 * The kdev_t and uuid of a device can never change once it is
260 * initially inserted.
262 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
264 struct hash_cell *cell, *hc;
267 * Allocate the new cells.
269 cell = alloc_cell(name, uuid, md);
274 * Insert the cell into both hash tables.
276 down_write(&_hash_lock);
277 hc = __get_name_cell(name);
286 hc = __get_uuid_cell(uuid);
295 mutex_lock(&dm_hash_cells_mutex);
296 dm_set_mdptr(md, cell);
297 mutex_unlock(&dm_hash_cells_mutex);
298 up_write(&_hash_lock);
303 up_write(&_hash_lock);
308 static struct dm_table *__hash_remove(struct hash_cell *hc)
310 struct dm_table *table;
313 lockdep_assert_held(&_hash_lock);
315 /* remove from the dev trees */
318 mutex_lock(&dm_hash_cells_mutex);
319 dm_set_mdptr(hc->md, NULL);
320 mutex_unlock(&dm_hash_cells_mutex);
322 table = dm_get_live_table(hc->md, &srcu_idx);
324 dm_table_event(table);
325 dm_put_live_table(hc->md, srcu_idx);
336 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
340 struct hash_cell *hc;
341 struct mapped_device *md;
347 down_write(&_hash_lock);
349 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
350 hc = container_of(n, struct hash_cell, name_node);
354 if (keep_open_devices &&
355 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
361 t = __hash_remove(hc);
363 up_write(&_hash_lock);
369 dm_ima_measure_on_device_remove(md, true);
371 if (likely(keep_open_devices))
374 dm_destroy_immediate(md);
377 * Some mapped devices may be using other mapped
378 * devices, so repeat until we make no further
379 * progress. If a new mapped device is created
380 * here it will also get removed.
385 up_write(&_hash_lock);
388 DMWARN("remove_all left %d open device(s)", dev_skipped);
392 * Set the uuid of a hash_cell that isn't already set.
394 static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
396 mutex_lock(&dm_hash_cells_mutex);
398 mutex_unlock(&dm_hash_cells_mutex);
404 * Changes the name of a hash_cell and returns the old name for
405 * the caller to free.
407 static char *__change_cell_name(struct hash_cell *hc, char *new_name)
412 * Rename and move the name cell.
417 mutex_lock(&dm_hash_cells_mutex);
419 mutex_unlock(&dm_hash_cells_mutex);
426 static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
429 char *new_data, *old_name = NULL;
430 struct hash_cell *hc;
431 struct dm_table *table;
432 struct mapped_device *md;
433 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
439 new_data = kstrdup(new, GFP_KERNEL);
441 return ERR_PTR(-ENOMEM);
443 down_write(&_hash_lock);
449 hc = __get_uuid_cell(new);
451 hc = __get_name_cell(new);
454 DMERR("Unable to change %s on mapped device %s to one that already exists: %s",
455 change_uuid ? "uuid" : "name",
458 up_write(&_hash_lock);
460 return ERR_PTR(-EBUSY);
464 * Is there such a device as 'old' ?
466 hc = __get_name_cell(param->name);
468 DMERR("Unable to rename non-existent device, %s to %s%s",
469 param->name, change_uuid ? "uuid " : "", new);
470 up_write(&_hash_lock);
472 return ERR_PTR(-ENXIO);
476 * Does this device already have a uuid?
478 if (change_uuid && hc->uuid) {
479 DMERR("Unable to change uuid of mapped device %s to %s "
480 "because uuid is already set to %s",
481 param->name, new, hc->uuid);
483 up_write(&_hash_lock);
485 return ERR_PTR(-EINVAL);
489 __set_cell_uuid(hc, new_data);
491 old_name = __change_cell_name(hc, new_data);
494 * Wake up any dm event waiters.
496 table = dm_get_live_table(hc->md, &srcu_idx);
498 dm_table_event(table);
499 dm_put_live_table(hc->md, srcu_idx);
501 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr, false))
502 param->flags |= DM_UEVENT_GENERATED_FLAG;
506 dm_ima_measure_on_device_rename(md);
508 up_write(&_hash_lock);
514 void dm_deferred_remove(void)
516 dm_hash_remove_all(true, false, true);
520 *---------------------------------------------------------------
521 * Implementation of the ioctl commands
522 *---------------------------------------------------------------
525 * All the ioctl commands get dispatched to functions with this
528 typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
530 static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
532 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
533 param->data_size = 0;
538 * Round up the ptr to an 8-byte boundary.
541 static inline size_t align_val(size_t val)
543 return (val + ALIGN_MASK) & ~ALIGN_MASK;
545 static inline void *align_ptr(void *ptr)
547 return (void *)align_val((size_t)ptr);
551 * Retrieves the data payload buffer from an already allocated
554 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
557 param->data_start = align_ptr(param + 1) - (void *) param;
559 if (param->data_start < param_size)
560 *len = param_size - param->data_start;
564 return ((void *) param) + param->data_start;
567 static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid)
570 size_t val_len, pfx_len;
573 val_len = strlen(val);
574 pfx_len = strnlen(pfx_name, DM_NAME_LEN);
575 if (pfx_len > val_len)
577 if (memcmp(val, pfx_name, pfx_len))
580 val = hc->uuid ? hc->uuid : "";
581 val_len = strlen(val);
582 pfx_len = strnlen(pfx_uuid, DM_UUID_LEN);
583 if (pfx_len > val_len)
585 if (memcmp(val, pfx_uuid, pfx_len))
591 static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
594 struct hash_cell *hc;
595 size_t len, needed = 0;
596 struct gendisk *disk;
597 struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
600 down_write(&_hash_lock);
603 * Loop through all the devices working out how much
606 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
607 hc = container_of(n, struct hash_cell, name_node);
608 if (!filter_device(hc, param->name, param->uuid))
610 needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
611 needed += align_val(sizeof(uint32_t) * 2);
612 if (param->flags & DM_UUID_FLAG && hc->uuid)
613 needed += align_val(strlen(hc->uuid) + 1);
617 * Grab our output buffer.
619 nl = orig_nl = get_result_buffer(param, param_size, &len);
620 if (len < needed || len < sizeof(nl->dev)) {
621 param->flags |= DM_BUFFER_FULL_FLAG;
624 param->data_size = param->data_start + needed;
626 nl->dev = 0; /* Flags no data */
629 * Now loop through filling out the names.
631 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
634 hc = container_of(n, struct hash_cell, name_node);
635 if (!filter_device(hc, param->name, param->uuid))
638 old_nl->next = (uint32_t) ((void *) nl -
640 disk = dm_disk(hc->md);
641 nl->dev = huge_encode_dev(disk_devt(disk));
643 strcpy(nl->name, hc->name);
646 event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
647 event_nr[0] = dm_get_event_nr(hc->md);
649 uuid_ptr = align_ptr(event_nr + 2);
650 if (param->flags & DM_UUID_FLAG) {
652 event_nr[1] |= DM_NAME_LIST_FLAG_HAS_UUID;
653 strcpy(uuid_ptr, hc->uuid);
654 uuid_ptr = align_ptr(uuid_ptr + strlen(hc->uuid) + 1);
656 event_nr[1] |= DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID;
662 * If mismatch happens, security may be compromised due to buffer
663 * overflow, so it's better to crash.
665 BUG_ON((char *)nl - (char *)orig_nl != needed);
668 up_write(&_hash_lock);
672 static void list_version_get_needed(struct target_type *tt, void *needed_param)
674 size_t *needed = needed_param;
676 *needed += sizeof(struct dm_target_versions);
677 *needed += strlen(tt->name) + 1;
678 *needed += ALIGN_MASK;
681 static void list_version_get_info(struct target_type *tt, void *param)
683 struct vers_iter *info = param;
685 /* Check space - it might have changed since the first iteration */
686 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > info->end) {
687 info->flags = DM_BUFFER_FULL_FLAG;
692 info->old_vers->next = (uint32_t) ((void *)info->vers - (void *)info->old_vers);
694 info->vers->version[0] = tt->version[0];
695 info->vers->version[1] = tt->version[1];
696 info->vers->version[2] = tt->version[2];
697 info->vers->next = 0;
698 strcpy(info->vers->name, tt->name);
700 info->old_vers = info->vers;
701 info->vers = align_ptr((void *)(info->vers + 1) + strlen(tt->name) + 1);
704 static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
706 size_t len, needed = 0;
707 struct dm_target_versions *vers;
708 struct vers_iter iter_info;
709 struct target_type *tt = NULL;
712 tt = dm_get_target_type(name);
718 * Loop through all the devices working out how much
722 dm_target_iterate(list_version_get_needed, &needed);
724 list_version_get_needed(tt, &needed);
727 * Grab our output buffer.
729 vers = get_result_buffer(param, param_size, &len);
731 param->flags |= DM_BUFFER_FULL_FLAG;
734 param->data_size = param->data_start + needed;
736 iter_info.param_size = param_size;
737 iter_info.old_vers = NULL;
738 iter_info.vers = vers;
740 iter_info.end = (char *)vers + needed;
743 * Now loop through filling out the names & versions.
746 dm_target_iterate(list_version_get_info, &iter_info);
748 list_version_get_info(tt, &iter_info);
749 param->flags |= iter_info.flags;
753 dm_put_target_type(tt);
757 static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
759 return __list_versions(param, param_size, NULL);
762 static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
764 return __list_versions(param, param_size, param->name);
767 static int check_name(const char *name)
769 if (strchr(name, '/')) {
770 DMERR("invalid device name");
778 * On successful return, the caller must not attempt to acquire
779 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
780 * waits for this dm_put_live_table and could be called under this lock.
782 static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
784 struct hash_cell *hc;
785 struct dm_table *table = NULL;
787 /* increment rcu count, we don't care about the table pointer */
788 dm_get_live_table(md, srcu_idx);
790 down_read(&_hash_lock);
791 hc = dm_get_mdptr(md);
793 DMERR("device has been removed from the dev hash table.");
800 up_read(&_hash_lock);
805 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
806 struct dm_ioctl *param,
809 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
810 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
814 * Fills in a dm_ioctl structure, ready for sending back to
817 static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
819 struct gendisk *disk = dm_disk(md);
820 struct dm_table *table;
823 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
824 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
826 if (dm_suspended_md(md))
827 param->flags |= DM_SUSPEND_FLAG;
829 if (dm_suspended_internally_md(md))
830 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
832 if (dm_test_deferred_remove_flag(md))
833 param->flags |= DM_DEFERRED_REMOVE;
835 param->dev = huge_encode_dev(disk_devt(disk));
838 * Yes, this will be out of date by the time it gets back
839 * to userland, but it is still very useful for
842 param->open_count = dm_open_count(md);
844 param->event_nr = dm_get_event_nr(md);
845 param->target_count = 0;
847 table = dm_get_live_table(md, &srcu_idx);
849 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
850 if (get_disk_ro(disk))
851 param->flags |= DM_READONLY_FLAG;
852 param->target_count = table->num_targets;
855 param->flags |= DM_ACTIVE_PRESENT_FLAG;
857 dm_put_live_table(md, srcu_idx);
859 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
862 table = dm_get_inactive_table(md, &srcu_idx);
864 if (!(dm_table_get_mode(table) & FMODE_WRITE))
865 param->flags |= DM_READONLY_FLAG;
866 param->target_count = table->num_targets;
868 dm_put_live_table(md, srcu_idx);
872 static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
874 int r, m = DM_ANY_MINOR;
875 struct mapped_device *md;
877 r = check_name(param->name);
881 if (param->flags & DM_PERSISTENT_DEV_FLAG)
882 m = MINOR(huge_decode_dev(param->dev));
884 r = dm_create(m, &md);
888 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
895 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
897 __dev_status(md, param);
905 * Always use UUID for lookups if it's present, otherwise use name or dev.
907 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
909 struct hash_cell *hc = NULL;
912 if (*param->name || param->dev) {
913 DMERR("Invalid ioctl structure: uuid %s, name %s, dev %llx",
914 param->uuid, param->name, (unsigned long long)param->dev);
918 hc = __get_uuid_cell(param->uuid);
921 } else if (*param->name) {
923 DMERR("Invalid ioctl structure: name %s, dev %llx",
924 param->name, (unsigned long long)param->dev);
928 hc = __get_name_cell(param->name);
931 } else if (param->dev) {
932 hc = __get_dev_cell(param->dev);
939 * Sneakily write in both the name and the uuid
940 * while we have the cell.
942 strscpy(param->name, hc->name, sizeof(param->name));
944 strscpy(param->uuid, hc->uuid, sizeof(param->uuid));
946 param->uuid[0] = '\0';
949 param->flags |= DM_INACTIVE_PRESENT_FLAG;
951 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
956 static struct mapped_device *find_device(struct dm_ioctl *param)
958 struct hash_cell *hc;
959 struct mapped_device *md = NULL;
961 down_read(&_hash_lock);
962 hc = __find_device_hash_cell(param);
965 up_read(&_hash_lock);
970 static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
972 struct hash_cell *hc;
973 struct mapped_device *md;
977 down_write(&_hash_lock);
978 hc = __find_device_hash_cell(param);
981 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
982 up_write(&_hash_lock);
989 * Ensure the device is not open and nothing further can open it.
991 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
993 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
994 up_write(&_hash_lock);
998 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
999 up_write(&_hash_lock);
1004 t = __hash_remove(hc);
1005 up_write(&_hash_lock);
1009 dm_table_destroy(t);
1012 param->flags &= ~DM_DEFERRED_REMOVE;
1014 dm_ima_measure_on_device_remove(md, false);
1016 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr, false))
1017 param->flags |= DM_UEVENT_GENERATED_FLAG;
1025 * Check a string doesn't overrun the chunk of
1026 * memory we copied from userland.
1028 static int invalid_str(char *str, void *end)
1030 while ((void *) str < end)
1037 static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
1040 char *new_data = (char *) param + param->data_start;
1041 struct mapped_device *md;
1042 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
1044 if (new_data < param->data ||
1045 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
1046 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
1047 DMERR("Invalid new mapped device name or uuid string supplied.");
1052 r = check_name(new_data);
1057 md = dm_hash_rename(param, new_data);
1061 __dev_status(md, param);
1067 static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
1070 struct mapped_device *md;
1071 struct hd_geometry geometry;
1072 unsigned long indata[4];
1073 char *geostr = (char *) param + param->data_start;
1076 md = find_device(param);
1080 if (geostr < param->data ||
1081 invalid_str(geostr, (void *) param + param_size)) {
1082 DMERR("Invalid geometry supplied.");
1086 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
1087 indata + 1, indata + 2, indata + 3, &dummy);
1090 DMERR("Unable to interpret geometry settings.");
1094 if (indata[0] > 65535 || indata[1] > 255 || indata[2] > 255) {
1095 DMERR("Geometry exceeds range limits.");
1099 geometry.cylinders = indata[0];
1100 geometry.heads = indata[1];
1101 geometry.sectors = indata[2];
1102 geometry.start = indata[3];
1104 r = dm_set_geometry(md, &geometry);
1106 param->data_size = 0;
1113 static int do_suspend(struct dm_ioctl *param)
1116 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1117 struct mapped_device *md;
1119 md = find_device(param);
1123 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1124 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1125 if (param->flags & DM_NOFLUSH_FLAG)
1126 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1128 if (!dm_suspended_md(md)) {
1129 r = dm_suspend(md, suspend_flags);
1134 __dev_status(md, param);
1142 static int do_resume(struct dm_ioctl *param)
1145 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1146 struct hash_cell *hc;
1147 struct mapped_device *md;
1148 struct dm_table *new_map, *old_map = NULL;
1149 bool need_resize_uevent = false;
1151 down_write(&_hash_lock);
1153 hc = __find_device_hash_cell(param);
1155 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1156 up_write(&_hash_lock);
1162 new_map = hc->new_map;
1164 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1166 up_write(&_hash_lock);
1168 /* Do we need to load a new map ? */
1170 sector_t old_size, new_size;
1173 /* Suspend if it isn't already suspended */
1174 old_map = dm_get_live_table(md, &srcu_idx);
1175 if ((param->flags & DM_SKIP_LOCKFS_FLAG) || !old_map)
1176 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1177 dm_put_live_table(md, srcu_idx);
1178 if (param->flags & DM_NOFLUSH_FLAG)
1179 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1180 if (!dm_suspended_md(md))
1181 dm_suspend(md, suspend_flags);
1183 old_size = dm_get_size(md);
1184 old_map = dm_swap_table(md, new_map);
1185 if (IS_ERR(old_map)) {
1187 dm_table_destroy(new_map);
1189 return PTR_ERR(old_map);
1191 new_size = dm_get_size(md);
1192 if (old_size && new_size && old_size != new_size)
1193 need_resize_uevent = true;
1195 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1196 set_disk_ro(dm_disk(md), 0);
1198 set_disk_ro(dm_disk(md), 1);
1201 if (dm_suspended_md(md)) {
1204 dm_ima_measure_on_device_resume(md, new_map ? true : false);
1206 if (!dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr, need_resize_uevent))
1207 param->flags |= DM_UEVENT_GENERATED_FLAG;
1212 * Since dm_swap_table synchronizes RCU, nobody should be in
1213 * read-side critical section already.
1216 dm_table_destroy(old_map);
1219 __dev_status(md, param);
1226 * Set or unset the suspension state of a device.
1227 * If the device already is in the requested state we just return its status.
1229 static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1231 if (param->flags & DM_SUSPEND_FLAG)
1232 return do_suspend(param);
1234 return do_resume(param);
1238 * Copies device info back to user space, used by
1239 * the create and info ioctls.
1241 static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1243 struct mapped_device *md;
1245 md = find_device(param);
1249 __dev_status(md, param);
1256 * Build up the status struct for each target
1258 static void retrieve_status(struct dm_table *table,
1259 struct dm_ioctl *param, size_t param_size)
1261 unsigned int i, num_targets;
1262 struct dm_target_spec *spec;
1263 char *outbuf, *outptr;
1265 size_t remaining, len, used = 0;
1266 unsigned int status_flags = 0;
1268 outptr = outbuf = get_result_buffer(param, param_size, &len);
1270 if (param->flags & DM_STATUS_TABLE_FLAG)
1271 type = STATUSTYPE_TABLE;
1272 else if (param->flags & DM_IMA_MEASUREMENT_FLAG)
1273 type = STATUSTYPE_IMA;
1275 type = STATUSTYPE_INFO;
1277 /* Get all the target info */
1278 num_targets = table->num_targets;
1279 for (i = 0; i < num_targets; i++) {
1280 struct dm_target *ti = dm_table_get_target(table, i);
1283 remaining = len - (outptr - outbuf);
1284 if (remaining <= sizeof(struct dm_target_spec)) {
1285 param->flags |= DM_BUFFER_FULL_FLAG;
1289 spec = (struct dm_target_spec *) outptr;
1292 spec->sector_start = ti->begin;
1293 spec->length = ti->len;
1294 strncpy(spec->target_type, ti->type->name,
1295 sizeof(spec->target_type) - 1);
1297 outptr += sizeof(struct dm_target_spec);
1298 remaining = len - (outptr - outbuf);
1299 if (remaining <= 0) {
1300 param->flags |= DM_BUFFER_FULL_FLAG;
1304 /* Get the status/table string from the target driver */
1305 if (ti->type->status) {
1306 if (param->flags & DM_NOFLUSH_FLAG)
1307 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1308 ti->type->status(ti, type, status_flags, outptr, remaining);
1312 l = strlen(outptr) + 1;
1313 if (l == remaining) {
1314 param->flags |= DM_BUFFER_FULL_FLAG;
1319 used = param->data_start + (outptr - outbuf);
1321 outptr = align_ptr(outptr);
1322 spec->next = outptr - outbuf;
1326 param->data_size = used;
1328 param->target_count = num_targets;
1332 * Wait for a device to report an event
1334 static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1337 struct mapped_device *md;
1338 struct dm_table *table;
1341 md = find_device(param);
1346 * Wait for a notification event
1348 if (dm_wait_event(md, param->event_nr)) {
1354 * The userland program is going to want to know what
1355 * changed to trigger the event, so we may as well tell
1356 * him and save an ioctl.
1358 __dev_status(md, param);
1360 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1362 retrieve_status(table, param, param_size);
1363 dm_put_live_table(md, srcu_idx);
1372 * Remember the global event number and make it possible to poll
1373 * for further events.
1375 static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1377 struct dm_file *priv = filp->private_data;
1379 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1384 static inline fmode_t get_mode(struct dm_ioctl *param)
1386 fmode_t mode = FMODE_READ | FMODE_WRITE;
1388 if (param->flags & DM_READONLY_FLAG)
1394 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1395 struct dm_target_spec **spec, char **target_params)
1397 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1398 *target_params = (char *) (*spec + 1);
1400 if (*spec < (last + 1))
1403 return invalid_str(*target_params, end);
1406 static int populate_table(struct dm_table *table,
1407 struct dm_ioctl *param, size_t param_size)
1411 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1412 uint32_t next = param->data_start;
1413 void *end = (void *) param + param_size;
1414 char *target_params;
1416 if (!param->target_count) {
1417 DMERR("%s: no targets specified", __func__);
1421 for (i = 0; i < param->target_count; i++) {
1423 r = next_target(spec, next, end, &spec, &target_params);
1425 DMERR("unable to find target");
1429 r = dm_table_add_target(table, spec->target_type,
1430 (sector_t) spec->sector_start,
1431 (sector_t) spec->length,
1434 DMERR("error adding target to table");
1441 return dm_table_complete(table);
1444 static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1447 (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1453 static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1456 struct hash_cell *hc;
1457 struct dm_table *t, *old_map = NULL;
1458 struct mapped_device *md;
1459 struct target_type *immutable_target_type;
1461 md = find_device(param);
1465 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1469 /* Protect md->type and md->queue against concurrent table loads. */
1470 dm_lock_md_type(md);
1471 r = populate_table(t, param, param_size);
1473 goto err_unlock_md_type;
1475 dm_ima_measure_on_table_load(t, STATUSTYPE_IMA);
1477 immutable_target_type = dm_get_immutable_target_type(md);
1478 if (immutable_target_type &&
1479 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1480 !dm_table_get_wildcard_target(t)) {
1481 DMERR("can't replace immutable target type %s",
1482 immutable_target_type->name);
1484 goto err_unlock_md_type;
1487 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1488 /* setup md->queue to reflect md's type (may block) */
1489 r = dm_setup_md_queue(md, t);
1491 DMERR("unable to set up device queue for new table.");
1492 goto err_unlock_md_type;
1494 } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
1495 DMERR("can't change device type (old=%u vs new=%u) after initial table load.",
1496 dm_get_md_type(md), dm_table_get_type(t));
1498 goto err_unlock_md_type;
1501 dm_unlock_md_type(md);
1503 /* stage inactive table */
1504 down_write(&_hash_lock);
1505 hc = dm_get_mdptr(md);
1507 DMERR("device has been removed from the dev hash table.");
1508 up_write(&_hash_lock);
1510 goto err_destroy_table;
1514 old_map = hc->new_map;
1516 up_write(&_hash_lock);
1518 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1519 __dev_status(md, param);
1523 dm_table_destroy(old_map);
1531 dm_unlock_md_type(md);
1533 dm_table_destroy(t);
1540 static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1542 struct hash_cell *hc;
1543 struct mapped_device *md;
1544 struct dm_table *old_map = NULL;
1545 bool has_new_map = false;
1547 down_write(&_hash_lock);
1549 hc = __find_device_hash_cell(param);
1551 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1552 up_write(&_hash_lock);
1557 old_map = hc->new_map;
1563 up_write(&_hash_lock);
1565 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1566 __dev_status(md, param);
1570 dm_table_destroy(old_map);
1572 dm_ima_measure_on_table_clear(md, has_new_map);
1579 * Retrieves a list of devices used by a particular dm device.
1581 static void retrieve_deps(struct dm_table *table,
1582 struct dm_ioctl *param, size_t param_size)
1584 unsigned int count = 0;
1585 struct list_head *tmp;
1587 struct dm_dev_internal *dd;
1588 struct dm_target_deps *deps;
1590 deps = get_result_buffer(param, param_size, &len);
1593 * Count the devices.
1595 list_for_each(tmp, dm_table_get_devices(table))
1599 * Check we have enough space.
1601 needed = struct_size(deps, dev, count);
1603 param->flags |= DM_BUFFER_FULL_FLAG;
1608 * Fill in the devices.
1610 deps->count = count;
1612 list_for_each_entry(dd, dm_table_get_devices(table), list)
1613 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1615 param->data_size = param->data_start + needed;
1618 static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1620 struct mapped_device *md;
1621 struct dm_table *table;
1624 md = find_device(param);
1628 __dev_status(md, param);
1630 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1632 retrieve_deps(table, param, param_size);
1633 dm_put_live_table(md, srcu_idx);
1641 * Return the status of a device as a text string for each
1644 static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1646 struct mapped_device *md;
1647 struct dm_table *table;
1650 md = find_device(param);
1654 __dev_status(md, param);
1656 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1658 retrieve_status(table, param, param_size);
1659 dm_put_live_table(md, srcu_idx);
1667 * Process device-mapper dependent messages. Messages prefixed with '@'
1668 * are processed by the DM core. All others are delivered to the target.
1669 * Returns a number <= 1 if message was processed by device mapper.
1670 * Returns 2 if message should be delivered to the target.
1672 static int message_for_md(struct mapped_device *md, unsigned int argc, char **argv,
1673 char *result, unsigned int maxlen)
1678 return 2; /* no '@' prefix, deliver to target */
1680 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1682 DMERR("Invalid arguments for @cancel_deferred_remove");
1685 return dm_cancel_deferred_remove(md);
1688 r = dm_stats_message(md, argc, argv, result, maxlen);
1692 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1697 * Pass a message to the target that's at the supplied device offset.
1699 static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1703 struct mapped_device *md;
1704 struct dm_table *table;
1705 struct dm_target *ti;
1706 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1708 char *result = get_result_buffer(param, param_size, &maxlen);
1711 md = find_device(param);
1715 if (tmsg < (struct dm_target_msg *) param->data ||
1716 invalid_str(tmsg->message, (void *) param + param_size)) {
1717 DMERR("Invalid target message parameters.");
1722 r = dm_split_args(&argc, &argv, tmsg->message);
1724 DMERR("Failed to split target message parameters");
1729 DMERR("Empty message received.");
1734 r = message_for_md(md, argc, argv, result, maxlen);
1738 table = dm_get_live_table(md, &srcu_idx);
1742 if (dm_deleting_md(md)) {
1747 ti = dm_table_find_target(table, tmsg->sector);
1749 DMERR("Target message sector outside device.");
1751 } else if (ti->type->message)
1752 r = ti->type->message(ti, argc, argv, result, maxlen);
1754 DMERR("Target type does not support messages");
1759 dm_put_live_table(md, srcu_idx);
1764 __dev_status(md, param);
1767 param->flags |= DM_DATA_OUT_FLAG;
1768 if (dm_message_test_buffer_overflow(result, maxlen))
1769 param->flags |= DM_BUFFER_FULL_FLAG;
1771 param->data_size = param->data_start + strlen(result) + 1;
1780 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1781 * followed by a data buffer. This flag is set if the second part,
1782 * which has a variable size, is not used by the function processing
1785 #define IOCTL_FLAGS_NO_PARAMS 1
1786 #define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
1789 *---------------------------------------------------------------
1790 * Implementation of open/close/ioctl on the special char device.
1791 *---------------------------------------------------------------
1793 static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1795 static const struct {
1800 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1801 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
1802 {DM_LIST_DEVICES_CMD, 0, list_devices},
1804 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
1805 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
1806 {DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
1807 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1808 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1809 {DM_DEV_WAIT_CMD, 0, dev_wait},
1811 {DM_TABLE_LOAD_CMD, 0, table_load},
1812 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1813 {DM_TABLE_DEPS_CMD, 0, table_deps},
1814 {DM_TABLE_STATUS_CMD, 0, table_status},
1816 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1818 {DM_TARGET_MSG_CMD, 0, target_message},
1819 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
1820 {DM_DEV_ARM_POLL_CMD, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
1821 {DM_GET_TARGET_VERSION_CMD, 0, get_target_version},
1824 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1827 cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
1828 *ioctl_flags = _ioctls[cmd].flags;
1829 return _ioctls[cmd].fn;
1833 * As well as checking the version compatibility this always
1834 * copies the kernel interface version out.
1836 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1838 uint32_t version[3];
1841 if (copy_from_user(version, user->version, sizeof(version)))
1844 if ((version[0] != DM_VERSION_MAJOR) ||
1845 (version[1] > DM_VERSION_MINOR)) {
1846 DMERR("ioctl interface mismatch: kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1847 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1848 DM_VERSION_PATCHLEVEL,
1849 version[0], version[1], version[2], cmd);
1854 * Fill in the kernel version.
1856 version[0] = DM_VERSION_MAJOR;
1857 version[1] = DM_VERSION_MINOR;
1858 version[2] = DM_VERSION_PATCHLEVEL;
1859 if (copy_to_user(user->version, version, sizeof(version)))
1865 #define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
1866 #define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1868 static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1870 if (param_flags & DM_WIPE_BUFFER)
1871 memset(param, 0, param_size);
1873 if (param_flags & DM_PARAMS_MALLOC)
1877 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1878 int ioctl_flags, struct dm_ioctl **param, int *param_flags)
1880 struct dm_ioctl *dmi;
1882 const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
1883 unsigned int noio_flag;
1885 if (copy_from_user(param_kernel, user, minimum_data_size))
1888 if (param_kernel->data_size < minimum_data_size) {
1889 DMERR("Invalid data size in the ioctl structure: %u",
1890 param_kernel->data_size);
1894 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1896 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1898 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1900 dmi->data_size = minimum_data_size;
1905 * Use __GFP_HIGH to avoid low memory issues when a device is
1906 * suspended and the ioctl is needed to resume it.
1907 * Use kmalloc() rather than vmalloc() when we can.
1910 noio_flag = memalloc_noio_save();
1911 dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);
1912 memalloc_noio_restore(noio_flag);
1915 if (secure_data && clear_user(user, param_kernel->data_size))
1920 *param_flags |= DM_PARAMS_MALLOC;
1922 /* Copy from param_kernel (which was already copied from user) */
1923 memcpy(dmi, param_kernel, minimum_data_size);
1925 if (copy_from_user(&dmi->data, (char __user *)user + minimum_data_size,
1926 param_kernel->data_size - minimum_data_size))
1929 /* Wipe the user buffer so we do not return it to userspace */
1930 if (secure_data && clear_user(user, param_kernel->data_size))
1937 free_params(dmi, param_kernel->data_size, *param_flags);
1942 static int validate_params(uint cmd, struct dm_ioctl *param)
1944 /* Always clear this flag */
1945 param->flags &= ~DM_BUFFER_FULL_FLAG;
1946 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1947 param->flags &= ~DM_SECURE_DATA_FLAG;
1948 param->flags &= ~DM_DATA_OUT_FLAG;
1950 /* Ignores parameters */
1951 if (cmd == DM_REMOVE_ALL_CMD ||
1952 cmd == DM_LIST_DEVICES_CMD ||
1953 cmd == DM_LIST_VERSIONS_CMD)
1956 if (cmd == DM_DEV_CREATE_CMD) {
1957 if (!*param->name) {
1958 DMERR("name not supplied when creating device");
1961 } else if (*param->uuid && *param->name) {
1962 DMERR("only supply one of name or uuid, cmd(%u)", cmd);
1966 /* Ensure strings are terminated */
1967 param->name[DM_NAME_LEN - 1] = '\0';
1968 param->uuid[DM_UUID_LEN - 1] = '\0';
1973 static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
1979 struct dm_ioctl *param;
1981 size_t input_param_size;
1982 struct dm_ioctl param_kernel;
1984 /* only root can play with this */
1985 if (!capable(CAP_SYS_ADMIN))
1988 if (_IOC_TYPE(command) != DM_IOCTL)
1991 cmd = _IOC_NR(command);
1994 * Check the interface version passed in. This also
1995 * writes out the kernel's interface version.
1997 r = check_version(cmd, user);
2002 * Nothing more to do for the version command.
2004 if (cmd == DM_VERSION_CMD)
2007 fn = lookup_ioctl(cmd, &ioctl_flags);
2009 DMERR("dm_ctl_ioctl: unknown command 0x%x", command);
2014 * Copy the parameters into kernel space.
2016 r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags);
2021 input_param_size = param->data_size;
2022 r = validate_params(cmd, param);
2026 param->data_size = offsetof(struct dm_ioctl, data);
2027 r = fn(file, param, input_param_size);
2029 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
2030 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
2031 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
2033 if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
2034 dm_issue_global_event();
2037 * Copy the results back to userland.
2039 if (!r && copy_to_user(user, param, param->data_size))
2043 free_params(param, input_param_size, param_flags);
2047 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
2049 return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
2052 #ifdef CONFIG_COMPAT
2053 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
2055 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
2058 #define dm_compat_ctl_ioctl NULL
2061 static int dm_open(struct inode *inode, struct file *filp)
2064 struct dm_file *priv;
2066 r = nonseekable_open(inode, filp);
2070 priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
2074 priv->global_event_nr = atomic_read(&dm_global_event_nr);
2079 static int dm_release(struct inode *inode, struct file *filp)
2081 kfree(filp->private_data);
2085 static __poll_t dm_poll(struct file *filp, poll_table *wait)
2087 struct dm_file *priv = filp->private_data;
2090 poll_wait(filp, &dm_global_eventq, wait);
2092 if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
2098 static const struct file_operations _ctl_fops = {
2100 .release = dm_release,
2102 .unlocked_ioctl = dm_ctl_ioctl,
2103 .compat_ioctl = dm_compat_ctl_ioctl,
2104 .owner = THIS_MODULE,
2105 .llseek = noop_llseek,
2108 static struct miscdevice _dm_misc = {
2109 .minor = MAPPER_CTRL_MINOR,
2111 .nodename = DM_DIR "/" DM_CONTROL_NODE,
2115 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
2116 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
2119 * Create misc character device and link to DM_DIR/control.
2121 int __init dm_interface_init(void)
2125 r = misc_register(&_dm_misc);
2127 DMERR("misc_register failed for control device");
2131 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
2132 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
2137 void dm_interface_exit(void)
2139 misc_deregister(&_dm_misc);
2144 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
2145 * @md: Pointer to mapped_device
2146 * @name: Buffer (size DM_NAME_LEN) for name
2147 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2149 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2152 struct hash_cell *hc;
2157 mutex_lock(&dm_hash_cells_mutex);
2158 hc = dm_get_mdptr(md);
2165 strcpy(name, hc->name);
2167 strcpy(uuid, hc->uuid ? : "");
2170 mutex_unlock(&dm_hash_cells_mutex);
2174 EXPORT_SYMBOL_GPL(dm_copy_name_and_uuid);
2177 * dm_early_create - create a mapped device in early boot.
2179 * @dmi: Contains main information of the device mapping to be created.
2180 * @spec_array: array of pointers to struct dm_target_spec. Describes the
2181 * mapping table of the device.
2182 * @target_params_array: array of strings with the parameters to a specific
2185 * Instead of having the struct dm_target_spec and the parameters for every
2186 * target embedded at the end of struct dm_ioctl (as performed in a normal
2187 * ioctl), pass them as arguments, so the caller doesn't need to serialize them.
2188 * The size of the spec_array and target_params_array is given by
2189 * @dmi->target_count.
2190 * This function is supposed to be called in early boot, so locking mechanisms
2191 * to protect against concurrent loads are not required.
2193 int __init dm_early_create(struct dm_ioctl *dmi,
2194 struct dm_target_spec **spec_array,
2195 char **target_params_array)
2197 int r, m = DM_ANY_MINOR;
2198 struct dm_table *t, *old_map;
2199 struct mapped_device *md;
2202 if (!dmi->target_count)
2205 r = check_name(dmi->name);
2209 if (dmi->flags & DM_PERSISTENT_DEV_FLAG)
2210 m = MINOR(huge_decode_dev(dmi->dev));
2212 /* alloc dm device */
2213 r = dm_create(m, &md);
2218 r = dm_hash_insert(dmi->name, *dmi->uuid ? dmi->uuid : NULL, md);
2220 goto err_destroy_dm;
2223 r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md);
2225 goto err_hash_remove;
2228 for (i = 0; i < dmi->target_count; i++) {
2229 r = dm_table_add_target(t, spec_array[i]->target_type,
2230 (sector_t) spec_array[i]->sector_start,
2231 (sector_t) spec_array[i]->length,
2232 target_params_array[i]);
2234 DMERR("error adding target to table");
2235 goto err_destroy_table;
2240 r = dm_table_complete(t);
2242 goto err_destroy_table;
2244 /* setup md->queue to reflect md's type (may block) */
2245 r = dm_setup_md_queue(md, t);
2247 DMERR("unable to set up device queue for new table.");
2248 goto err_destroy_table;
2253 old_map = dm_swap_table(md, t);
2254 if (IS_ERR(old_map)) {
2255 r = PTR_ERR(old_map);
2256 goto err_destroy_table;
2258 set_disk_ro(dm_disk(md), !!(dmi->flags & DM_READONLY_FLAG));
2263 goto err_destroy_table;
2265 DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name);
2270 dm_table_destroy(t);
2272 down_write(&_hash_lock);
2273 (void) __hash_remove(__get_name_cell(dmi->name));
2274 up_write(&_hash_lock);
2275 /* release reference from __get_name_cell */