2 * Copyright (C) 2001 Sistina Software (UK) Limited.
3 * Copyright (C) 2004-2008 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/blkdev.h>
13 #include <linux/namei.h>
14 #include <linux/ctype.h>
15 #include <linux/string.h>
16 #include <linux/slab.h>
17 #include <linux/interrupt.h>
18 #include <linux/mutex.h>
19 #include <linux/delay.h>
20 #include <linux/atomic.h>
21 #include <linux/blk-mq.h>
22 #include <linux/mount.h>
24 #define DM_MSG_PREFIX "table"
27 #define NODE_SIZE L1_CACHE_BYTES
28 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
29 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
32 struct mapped_device
*md
;
33 enum dm_queue_mode type
;
37 unsigned int counts
[MAX_DEPTH
]; /* in nodes */
38 sector_t
*index
[MAX_DEPTH
];
40 unsigned int num_targets
;
41 unsigned int num_allocated
;
43 struct dm_target
*targets
;
45 struct target_type
*immutable_target_type
;
47 bool integrity_supported
:1;
50 unsigned integrity_added
:1;
53 * Indicates the rw permissions for the new logical
54 * device. This should be a combination of FMODE_READ
59 /* a list of devices used by this table */
60 struct list_head devices
;
62 /* events get handed up using this callback */
63 void (*event_fn
)(void *);
66 struct dm_md_mempools
*mempools
;
68 struct list_head target_callbacks
;
72 * Similar to ceiling(log_size(n))
74 static unsigned int int_log(unsigned int n
, unsigned int base
)
79 n
= dm_div_up(n
, base
);
87 * Calculate the index of the child node of the n'th node k'th key.
89 static inline unsigned int get_child(unsigned int n
, unsigned int k
)
91 return (n
* CHILDREN_PER_NODE
) + k
;
95 * Return the n'th node of level l from table t.
97 static inline sector_t
*get_node(struct dm_table
*t
,
98 unsigned int l
, unsigned int n
)
100 return t
->index
[l
] + (n
* KEYS_PER_NODE
);
104 * Return the highest key that you could lookup from the n'th
105 * node on level l of the btree.
107 static sector_t
high(struct dm_table
*t
, unsigned int l
, unsigned int n
)
109 for (; l
< t
->depth
- 1; l
++)
110 n
= get_child(n
, CHILDREN_PER_NODE
- 1);
112 if (n
>= t
->counts
[l
])
113 return (sector_t
) - 1;
115 return get_node(t
, l
, n
)[KEYS_PER_NODE
- 1];
119 * Fills in a level of the btree based on the highs of the level
122 static int setup_btree_index(unsigned int l
, struct dm_table
*t
)
127 for (n
= 0U; n
< t
->counts
[l
]; n
++) {
128 node
= get_node(t
, l
, n
);
130 for (k
= 0U; k
< KEYS_PER_NODE
; k
++)
131 node
[k
] = high(t
, l
+ 1, get_child(n
, k
));
137 void *dm_vcalloc(unsigned long nmemb
, unsigned long elem_size
)
143 * Check that we're not going to overflow.
145 if (nmemb
> (ULONG_MAX
/ elem_size
))
148 size
= nmemb
* elem_size
;
149 addr
= vzalloc(size
);
153 EXPORT_SYMBOL(dm_vcalloc
);
156 * highs, and targets are managed as dynamic arrays during a
159 static int alloc_targets(struct dm_table
*t
, unsigned int num
)
162 struct dm_target
*n_targets
;
165 * Allocate both the target array and offset array at once.
166 * Append an empty entry to catch sectors beyond the end of
169 n_highs
= (sector_t
*) dm_vcalloc(num
+ 1, sizeof(struct dm_target
) +
174 n_targets
= (struct dm_target
*) (n_highs
+ num
);
176 memset(n_highs
, -1, sizeof(*n_highs
) * num
);
179 t
->num_allocated
= num
;
181 t
->targets
= n_targets
;
186 int dm_table_create(struct dm_table
**result
, fmode_t mode
,
187 unsigned num_targets
, struct mapped_device
*md
)
189 struct dm_table
*t
= kzalloc(sizeof(*t
), GFP_KERNEL
);
194 INIT_LIST_HEAD(&t
->devices
);
195 INIT_LIST_HEAD(&t
->target_callbacks
);
198 num_targets
= KEYS_PER_NODE
;
200 num_targets
= dm_round_up(num_targets
, KEYS_PER_NODE
);
207 if (alloc_targets(t
, num_targets
)) {
212 t
->type
= DM_TYPE_NONE
;
219 static void free_devices(struct list_head
*devices
, struct mapped_device
*md
)
221 struct list_head
*tmp
, *next
;
223 list_for_each_safe(tmp
, next
, devices
) {
224 struct dm_dev_internal
*dd
=
225 list_entry(tmp
, struct dm_dev_internal
, list
);
226 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
227 dm_device_name(md
), dd
->dm_dev
->name
);
228 dm_put_table_device(md
, dd
->dm_dev
);
233 void dm_table_destroy(struct dm_table
*t
)
240 /* free the indexes */
242 vfree(t
->index
[t
->depth
- 2]);
244 /* free the targets */
245 for (i
= 0; i
< t
->num_targets
; i
++) {
246 struct dm_target
*tgt
= t
->targets
+ i
;
251 dm_put_target_type(tgt
->type
);
256 /* free the device list */
257 free_devices(&t
->devices
, t
->md
);
259 dm_free_md_mempools(t
->mempools
);
265 * See if we've already got a device in the list.
267 static struct dm_dev_internal
*find_device(struct list_head
*l
, dev_t dev
)
269 struct dm_dev_internal
*dd
;
271 list_for_each_entry (dd
, l
, list
)
272 if (dd
->dm_dev
->bdev
->bd_dev
== dev
)
279 * If possible, this checks an area of a destination device is invalid.
281 static int device_area_is_invalid(struct dm_target
*ti
, struct dm_dev
*dev
,
282 sector_t start
, sector_t len
, void *data
)
284 struct request_queue
*q
;
285 struct queue_limits
*limits
= data
;
286 struct block_device
*bdev
= dev
->bdev
;
288 i_size_read(bdev
->bd_inode
) >> SECTOR_SHIFT
;
289 unsigned short logical_block_size_sectors
=
290 limits
->logical_block_size
>> SECTOR_SHIFT
;
291 char b
[BDEVNAME_SIZE
];
294 * Some devices exist without request functions,
295 * such as loop devices not yet bound to backing files.
296 * Forbid the use of such devices.
298 q
= bdev_get_queue(bdev
);
299 if (!q
|| !q
->make_request_fn
) {
300 DMWARN("%s: %s is not yet initialised: "
301 "start=%llu, len=%llu, dev_size=%llu",
302 dm_device_name(ti
->table
->md
), bdevname(bdev
, b
),
303 (unsigned long long)start
,
304 (unsigned long long)len
,
305 (unsigned long long)dev_size
);
312 if ((start
>= dev_size
) || (start
+ len
> dev_size
)) {
313 DMWARN("%s: %s too small for target: "
314 "start=%llu, len=%llu, dev_size=%llu",
315 dm_device_name(ti
->table
->md
), bdevname(bdev
, b
),
316 (unsigned long long)start
,
317 (unsigned long long)len
,
318 (unsigned long long)dev_size
);
322 if (logical_block_size_sectors
<= 1)
325 if (start
& (logical_block_size_sectors
- 1)) {
326 DMWARN("%s: start=%llu not aligned to h/w "
327 "logical block size %u of %s",
328 dm_device_name(ti
->table
->md
),
329 (unsigned long long)start
,
330 limits
->logical_block_size
, bdevname(bdev
, b
));
334 if (len
& (logical_block_size_sectors
- 1)) {
335 DMWARN("%s: len=%llu not aligned to h/w "
336 "logical block size %u of %s",
337 dm_device_name(ti
->table
->md
),
338 (unsigned long long)len
,
339 limits
->logical_block_size
, bdevname(bdev
, b
));
347 * This upgrades the mode on an already open dm_dev, being
348 * careful to leave things as they were if we fail to reopen the
349 * device and not to touch the existing bdev field in case
350 * it is accessed concurrently inside dm_table_any_congested().
352 static int upgrade_mode(struct dm_dev_internal
*dd
, fmode_t new_mode
,
353 struct mapped_device
*md
)
356 struct dm_dev
*old_dev
, *new_dev
;
358 old_dev
= dd
->dm_dev
;
360 r
= dm_get_table_device(md
, dd
->dm_dev
->bdev
->bd_dev
,
361 dd
->dm_dev
->mode
| new_mode
, &new_dev
);
365 dd
->dm_dev
= new_dev
;
366 dm_put_table_device(md
, old_dev
);
372 * Convert the path to a device
374 dev_t
dm_get_dev_t(const char *path
)
377 struct block_device
*bdev
;
379 bdev
= lookup_bdev(path
);
381 dev
= name_to_dev_t(path
);
389 EXPORT_SYMBOL_GPL(dm_get_dev_t
);
392 * Add a device to the list, or just increment the usage count if
393 * it's already present.
395 int dm_get_device(struct dm_target
*ti
, const char *path
, fmode_t mode
,
396 struct dm_dev
**result
)
400 struct dm_dev_internal
*dd
;
401 struct dm_table
*t
= ti
->table
;
405 dev
= dm_get_dev_t(path
);
409 dd
= find_device(&t
->devices
, dev
);
411 dd
= kmalloc(sizeof(*dd
), GFP_KERNEL
);
415 if ((r
= dm_get_table_device(t
->md
, dev
, mode
, &dd
->dm_dev
))) {
420 atomic_set(&dd
->count
, 0);
421 list_add(&dd
->list
, &t
->devices
);
423 } else if (dd
->dm_dev
->mode
!= (mode
| dd
->dm_dev
->mode
)) {
424 r
= upgrade_mode(dd
, mode
, t
->md
);
428 atomic_inc(&dd
->count
);
430 *result
= dd
->dm_dev
;
433 EXPORT_SYMBOL(dm_get_device
);
435 static int dm_set_device_limits(struct dm_target
*ti
, struct dm_dev
*dev
,
436 sector_t start
, sector_t len
, void *data
)
438 struct queue_limits
*limits
= data
;
439 struct block_device
*bdev
= dev
->bdev
;
440 struct request_queue
*q
= bdev_get_queue(bdev
);
441 char b
[BDEVNAME_SIZE
];
444 DMWARN("%s: Cannot set limits for nonexistent device %s",
445 dm_device_name(ti
->table
->md
), bdevname(bdev
, b
));
449 if (bdev_stack_limits(limits
, bdev
, start
) < 0)
450 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
451 "physical_block_size=%u, logical_block_size=%u, "
452 "alignment_offset=%u, start=%llu",
453 dm_device_name(ti
->table
->md
), bdevname(bdev
, b
),
454 q
->limits
.physical_block_size
,
455 q
->limits
.logical_block_size
,
456 q
->limits
.alignment_offset
,
457 (unsigned long long) start
<< SECTOR_SHIFT
);
463 * Decrement a device's use count and remove it if necessary.
465 void dm_put_device(struct dm_target
*ti
, struct dm_dev
*d
)
468 struct list_head
*devices
= &ti
->table
->devices
;
469 struct dm_dev_internal
*dd
;
471 list_for_each_entry(dd
, devices
, list
) {
472 if (dd
->dm_dev
== d
) {
478 DMWARN("%s: device %s not in table devices list",
479 dm_device_name(ti
->table
->md
), d
->name
);
482 if (atomic_dec_and_test(&dd
->count
)) {
483 dm_put_table_device(ti
->table
->md
, d
);
488 EXPORT_SYMBOL(dm_put_device
);
491 * Checks to see if the target joins onto the end of the table.
493 static int adjoin(struct dm_table
*table
, struct dm_target
*ti
)
495 struct dm_target
*prev
;
497 if (!table
->num_targets
)
500 prev
= &table
->targets
[table
->num_targets
- 1];
501 return (ti
->begin
== (prev
->begin
+ prev
->len
));
505 * Used to dynamically allocate the arg array.
507 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
508 * process messages even if some device is suspended. These messages have a
509 * small fixed number of arguments.
511 * On the other hand, dm-switch needs to process bulk data using messages and
512 * excessive use of GFP_NOIO could cause trouble.
514 static char **realloc_argv(unsigned *array_size
, char **old_argv
)
521 new_size
= *array_size
* 2;
527 argv
= kmalloc(new_size
* sizeof(*argv
), gfp
);
529 memcpy(argv
, old_argv
, *array_size
* sizeof(*argv
));
530 *array_size
= new_size
;
538 * Destructively splits up the argument list to pass to ctr.
540 int dm_split_args(int *argc
, char ***argvp
, char *input
)
542 char *start
, *end
= input
, *out
, **argv
= NULL
;
543 unsigned array_size
= 0;
552 argv
= realloc_argv(&array_size
, argv
);
557 /* Skip whitespace */
558 start
= skip_spaces(end
);
561 break; /* success, we hit the end */
563 /* 'out' is used to remove any back-quotes */
566 /* Everything apart from '\0' can be quoted */
567 if (*end
== '\\' && *(end
+ 1)) {
574 break; /* end of token */
579 /* have we already filled the array ? */
580 if ((*argc
+ 1) > array_size
) {
581 argv
= realloc_argv(&array_size
, argv
);
586 /* we know this is whitespace */
590 /* terminate the string and put it in the array */
601 * Impose necessary and sufficient conditions on a devices's table such
602 * that any incoming bio which respects its logical_block_size can be
603 * processed successfully. If it falls across the boundary between
604 * two or more targets, the size of each piece it gets split into must
605 * be compatible with the logical_block_size of the target processing it.
607 static int validate_hardware_logical_block_alignment(struct dm_table
*table
,
608 struct queue_limits
*limits
)
611 * This function uses arithmetic modulo the logical_block_size
612 * (in units of 512-byte sectors).
614 unsigned short device_logical_block_size_sects
=
615 limits
->logical_block_size
>> SECTOR_SHIFT
;
618 * Offset of the start of the next table entry, mod logical_block_size.
620 unsigned short next_target_start
= 0;
623 * Given an aligned bio that extends beyond the end of a
624 * target, how many sectors must the next target handle?
626 unsigned short remaining
= 0;
628 struct dm_target
*uninitialized_var(ti
);
629 struct queue_limits ti_limits
;
633 * Check each entry in the table in turn.
635 for (i
= 0; i
< dm_table_get_num_targets(table
); i
++) {
636 ti
= dm_table_get_target(table
, i
);
638 blk_set_stacking_limits(&ti_limits
);
640 /* combine all target devices' limits */
641 if (ti
->type
->iterate_devices
)
642 ti
->type
->iterate_devices(ti
, dm_set_device_limits
,
646 * If the remaining sectors fall entirely within this
647 * table entry are they compatible with its logical_block_size?
649 if (remaining
< ti
->len
&&
650 remaining
& ((ti_limits
.logical_block_size
>>
655 (unsigned short) ((next_target_start
+ ti
->len
) &
656 (device_logical_block_size_sects
- 1));
657 remaining
= next_target_start
?
658 device_logical_block_size_sects
- next_target_start
: 0;
662 DMWARN("%s: table line %u (start sect %llu len %llu) "
663 "not aligned to h/w logical block size %u",
664 dm_device_name(table
->md
), i
,
665 (unsigned long long) ti
->begin
,
666 (unsigned long long) ti
->len
,
667 limits
->logical_block_size
);
674 int dm_table_add_target(struct dm_table
*t
, const char *type
,
675 sector_t start
, sector_t len
, char *params
)
677 int r
= -EINVAL
, argc
;
679 struct dm_target
*tgt
;
682 DMERR("%s: target type %s must appear alone in table",
683 dm_device_name(t
->md
), t
->targets
->type
->name
);
687 BUG_ON(t
->num_targets
>= t
->num_allocated
);
689 tgt
= t
->targets
+ t
->num_targets
;
690 memset(tgt
, 0, sizeof(*tgt
));
693 DMERR("%s: zero-length target", dm_device_name(t
->md
));
697 tgt
->type
= dm_get_target_type(type
);
699 DMERR("%s: %s: unknown target type", dm_device_name(t
->md
), type
);
703 if (dm_target_needs_singleton(tgt
->type
)) {
704 if (t
->num_targets
) {
705 tgt
->error
= "singleton target type must appear alone in table";
711 if (dm_target_always_writeable(tgt
->type
) && !(t
->mode
& FMODE_WRITE
)) {
712 tgt
->error
= "target type may not be included in a read-only table";
716 if (t
->immutable_target_type
) {
717 if (t
->immutable_target_type
!= tgt
->type
) {
718 tgt
->error
= "immutable target type cannot be mixed with other target types";
721 } else if (dm_target_is_immutable(tgt
->type
)) {
722 if (t
->num_targets
) {
723 tgt
->error
= "immutable target type cannot be mixed with other target types";
726 t
->immutable_target_type
= tgt
->type
;
729 if (dm_target_has_integrity(tgt
->type
))
730 t
->integrity_added
= 1;
735 tgt
->error
= "Unknown error";
738 * Does this target adjoin the previous one ?
740 if (!adjoin(t
, tgt
)) {
741 tgt
->error
= "Gap in table";
745 r
= dm_split_args(&argc
, &argv
, params
);
747 tgt
->error
= "couldn't split parameters (insufficient memory)";
751 r
= tgt
->type
->ctr(tgt
, argc
, argv
);
756 t
->highs
[t
->num_targets
++] = tgt
->begin
+ tgt
->len
- 1;
758 if (!tgt
->num_discard_bios
&& tgt
->discards_supported
)
759 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
760 dm_device_name(t
->md
), type
);
765 DMERR("%s: %s: %s", dm_device_name(t
->md
), type
, tgt
->error
);
766 dm_put_target_type(tgt
->type
);
771 * Target argument parsing helpers.
773 static int validate_next_arg(struct dm_arg
*arg
, struct dm_arg_set
*arg_set
,
774 unsigned *value
, char **error
, unsigned grouped
)
776 const char *arg_str
= dm_shift_arg(arg_set
);
780 (sscanf(arg_str
, "%u%c", value
, &dummy
) != 1) ||
781 (*value
< arg
->min
) ||
782 (*value
> arg
->max
) ||
783 (grouped
&& arg_set
->argc
< *value
)) {
791 int dm_read_arg(struct dm_arg
*arg
, struct dm_arg_set
*arg_set
,
792 unsigned *value
, char **error
)
794 return validate_next_arg(arg
, arg_set
, value
, error
, 0);
796 EXPORT_SYMBOL(dm_read_arg
);
798 int dm_read_arg_group(struct dm_arg
*arg
, struct dm_arg_set
*arg_set
,
799 unsigned *value
, char **error
)
801 return validate_next_arg(arg
, arg_set
, value
, error
, 1);
803 EXPORT_SYMBOL(dm_read_arg_group
);
805 const char *dm_shift_arg(struct dm_arg_set
*as
)
818 EXPORT_SYMBOL(dm_shift_arg
);
820 void dm_consume_args(struct dm_arg_set
*as
, unsigned num_args
)
822 BUG_ON(as
->argc
< num_args
);
823 as
->argc
-= num_args
;
824 as
->argv
+= num_args
;
826 EXPORT_SYMBOL(dm_consume_args
);
828 static bool __table_type_bio_based(enum dm_queue_mode table_type
)
830 return (table_type
== DM_TYPE_BIO_BASED
||
831 table_type
== DM_TYPE_DAX_BIO_BASED
);
834 static bool __table_type_request_based(enum dm_queue_mode table_type
)
836 return (table_type
== DM_TYPE_REQUEST_BASED
||
837 table_type
== DM_TYPE_MQ_REQUEST_BASED
);
840 void dm_table_set_type(struct dm_table
*t
, enum dm_queue_mode type
)
844 EXPORT_SYMBOL_GPL(dm_table_set_type
);
846 static int device_supports_dax(struct dm_target
*ti
, struct dm_dev
*dev
,
847 sector_t start
, sector_t len
, void *data
)
849 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
851 return q
&& blk_queue_dax(q
);
854 static bool dm_table_supports_dax(struct dm_table
*t
)
856 struct dm_target
*ti
;
859 /* Ensure that all targets support DAX. */
860 for (i
= 0; i
< dm_table_get_num_targets(t
); i
++) {
861 ti
= dm_table_get_target(t
, i
);
863 if (!ti
->type
->direct_access
)
866 if (!ti
->type
->iterate_devices
||
867 !ti
->type
->iterate_devices(ti
, device_supports_dax
, NULL
))
874 static int dm_table_determine_type(struct dm_table
*t
)
877 unsigned bio_based
= 0, request_based
= 0, hybrid
= 0;
878 unsigned sq_count
= 0, mq_count
= 0;
879 struct dm_target
*tgt
;
880 struct dm_dev_internal
*dd
;
881 struct list_head
*devices
= dm_table_get_devices(t
);
882 enum dm_queue_mode live_md_type
= dm_get_md_type(t
->md
);
884 if (t
->type
!= DM_TYPE_NONE
) {
885 /* target already set the table's type */
886 if (t
->type
== DM_TYPE_BIO_BASED
)
888 BUG_ON(t
->type
== DM_TYPE_DAX_BIO_BASED
);
889 goto verify_rq_based
;
892 for (i
= 0; i
< t
->num_targets
; i
++) {
893 tgt
= t
->targets
+ i
;
894 if (dm_target_hybrid(tgt
))
896 else if (dm_target_request_based(tgt
))
901 if (bio_based
&& request_based
) {
902 DMWARN("Inconsistent table: different target types"
903 " can't be mixed up");
908 if (hybrid
&& !bio_based
&& !request_based
) {
910 * The targets can work either way.
911 * Determine the type from the live device.
912 * Default to bio-based if device is new.
914 if (__table_type_request_based(live_md_type
))
921 /* We must use this table as bio-based */
922 t
->type
= DM_TYPE_BIO_BASED
;
923 if (dm_table_supports_dax(t
) ||
924 (list_empty(devices
) && live_md_type
== DM_TYPE_DAX_BIO_BASED
))
925 t
->type
= DM_TYPE_DAX_BIO_BASED
;
929 BUG_ON(!request_based
); /* No targets in this table */
932 * The only way to establish DM_TYPE_MQ_REQUEST_BASED is by
933 * having a compatible target use dm_table_set_type.
935 t
->type
= DM_TYPE_REQUEST_BASED
;
939 * Request-based dm supports only tables that have a single target now.
940 * To support multiple targets, request splitting support is needed,
941 * and that needs lots of changes in the block-layer.
942 * (e.g. request completion process for partial completion.)
944 if (t
->num_targets
> 1) {
945 DMWARN("Request-based dm doesn't support multiple targets yet");
949 if (list_empty(devices
)) {
951 struct dm_table
*live_table
= dm_get_live_table(t
->md
, &srcu_idx
);
953 /* inherit live table's type and all_blk_mq */
955 t
->type
= live_table
->type
;
956 t
->all_blk_mq
= live_table
->all_blk_mq
;
958 dm_put_live_table(t
->md
, srcu_idx
);
962 /* Non-request-stackable devices can't be used for request-based dm */
963 list_for_each_entry(dd
, devices
, list
) {
964 struct request_queue
*q
= bdev_get_queue(dd
->dm_dev
->bdev
);
966 if (!blk_queue_stackable(q
)) {
967 DMERR("table load rejected: including"
968 " non-request-stackable devices");
977 if (sq_count
&& mq_count
) {
978 DMERR("table load rejected: not all devices are blk-mq request-stackable");
981 t
->all_blk_mq
= mq_count
> 0;
983 if (t
->type
== DM_TYPE_MQ_REQUEST_BASED
&& !t
->all_blk_mq
) {
984 DMERR("table load rejected: all devices are not blk-mq request-stackable");
991 enum dm_queue_mode
dm_table_get_type(struct dm_table
*t
)
996 struct target_type
*dm_table_get_immutable_target_type(struct dm_table
*t
)
998 return t
->immutable_target_type
;
1001 struct dm_target
*dm_table_get_immutable_target(struct dm_table
*t
)
1003 /* Immutable target is implicitly a singleton */
1004 if (t
->num_targets
> 1 ||
1005 !dm_target_is_immutable(t
->targets
[0].type
))
1011 struct dm_target
*dm_table_get_wildcard_target(struct dm_table
*t
)
1013 struct dm_target
*ti
;
1016 for (i
= 0; i
< dm_table_get_num_targets(t
); i
++) {
1017 ti
= dm_table_get_target(t
, i
);
1018 if (dm_target_is_wildcard(ti
->type
))
1025 bool dm_table_bio_based(struct dm_table
*t
)
1027 return __table_type_bio_based(dm_table_get_type(t
));
1030 bool dm_table_request_based(struct dm_table
*t
)
1032 return __table_type_request_based(dm_table_get_type(t
));
1035 bool dm_table_all_blk_mq_devices(struct dm_table
*t
)
1037 return t
->all_blk_mq
;
1040 static int dm_table_alloc_md_mempools(struct dm_table
*t
, struct mapped_device
*md
)
1042 enum dm_queue_mode type
= dm_table_get_type(t
);
1043 unsigned per_io_data_size
= 0;
1044 struct dm_target
*tgt
;
1047 if (unlikely(type
== DM_TYPE_NONE
)) {
1048 DMWARN("no table type is set, can't allocate mempools");
1052 if (__table_type_bio_based(type
))
1053 for (i
= 0; i
< t
->num_targets
; i
++) {
1054 tgt
= t
->targets
+ i
;
1055 per_io_data_size
= max(per_io_data_size
, tgt
->per_io_data_size
);
1058 t
->mempools
= dm_alloc_md_mempools(md
, type
, t
->integrity_supported
, per_io_data_size
);
1065 void dm_table_free_md_mempools(struct dm_table
*t
)
1067 dm_free_md_mempools(t
->mempools
);
1071 struct dm_md_mempools
*dm_table_get_md_mempools(struct dm_table
*t
)
1076 static int setup_indexes(struct dm_table
*t
)
1079 unsigned int total
= 0;
1082 /* allocate the space for *all* the indexes */
1083 for (i
= t
->depth
- 2; i
>= 0; i
--) {
1084 t
->counts
[i
] = dm_div_up(t
->counts
[i
+ 1], CHILDREN_PER_NODE
);
1085 total
+= t
->counts
[i
];
1088 indexes
= (sector_t
*) dm_vcalloc(total
, (unsigned long) NODE_SIZE
);
1092 /* set up internal nodes, bottom-up */
1093 for (i
= t
->depth
- 2; i
>= 0; i
--) {
1094 t
->index
[i
] = indexes
;
1095 indexes
+= (KEYS_PER_NODE
* t
->counts
[i
]);
1096 setup_btree_index(i
, t
);
1103 * Builds the btree to index the map.
1105 static int dm_table_build_index(struct dm_table
*t
)
1108 unsigned int leaf_nodes
;
1110 /* how many indexes will the btree have ? */
1111 leaf_nodes
= dm_div_up(t
->num_targets
, KEYS_PER_NODE
);
1112 t
->depth
= 1 + int_log(leaf_nodes
, CHILDREN_PER_NODE
);
1114 /* leaf layer has already been set up */
1115 t
->counts
[t
->depth
- 1] = leaf_nodes
;
1116 t
->index
[t
->depth
- 1] = t
->highs
;
1119 r
= setup_indexes(t
);
1124 static bool integrity_profile_exists(struct gendisk
*disk
)
1126 return !!blk_get_integrity(disk
);
1130 * Get a disk whose integrity profile reflects the table's profile.
1131 * Returns NULL if integrity support was inconsistent or unavailable.
1133 static struct gendisk
* dm_table_get_integrity_disk(struct dm_table
*t
)
1135 struct list_head
*devices
= dm_table_get_devices(t
);
1136 struct dm_dev_internal
*dd
= NULL
;
1137 struct gendisk
*prev_disk
= NULL
, *template_disk
= NULL
;
1140 for (i
= 0; i
< dm_table_get_num_targets(t
); i
++) {
1141 struct dm_target
*ti
= dm_table_get_target(t
, i
);
1142 if (!dm_target_passes_integrity(ti
->type
))
1146 list_for_each_entry(dd
, devices
, list
) {
1147 template_disk
= dd
->dm_dev
->bdev
->bd_disk
;
1148 if (!integrity_profile_exists(template_disk
))
1150 else if (prev_disk
&&
1151 blk_integrity_compare(prev_disk
, template_disk
) < 0)
1153 prev_disk
= template_disk
;
1156 return template_disk
;
1160 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1161 dm_device_name(t
->md
),
1162 prev_disk
->disk_name
,
1163 template_disk
->disk_name
);
1168 * Register the mapped device for blk_integrity support if the
1169 * underlying devices have an integrity profile. But all devices may
1170 * not have matching profiles (checking all devices isn't reliable
1171 * during table load because this table may use other DM device(s) which
1172 * must be resumed before they will have an initialized integity
1173 * profile). Consequently, stacked DM devices force a 2 stage integrity
1174 * profile validation: First pass during table load, final pass during
1177 static int dm_table_register_integrity(struct dm_table
*t
)
1179 struct mapped_device
*md
= t
->md
;
1180 struct gendisk
*template_disk
= NULL
;
1182 /* If target handles integrity itself do not register it here. */
1183 if (t
->integrity_added
)
1186 template_disk
= dm_table_get_integrity_disk(t
);
1190 if (!integrity_profile_exists(dm_disk(md
))) {
1191 t
->integrity_supported
= true;
1193 * Register integrity profile during table load; we can do
1194 * this because the final profile must match during resume.
1196 blk_integrity_register(dm_disk(md
),
1197 blk_get_integrity(template_disk
));
1202 * If DM device already has an initialized integrity
1203 * profile the new profile should not conflict.
1205 if (blk_integrity_compare(dm_disk(md
), template_disk
) < 0) {
1206 DMWARN("%s: conflict with existing integrity profile: "
1207 "%s profile mismatch",
1208 dm_device_name(t
->md
),
1209 template_disk
->disk_name
);
1213 /* Preserve existing integrity profile */
1214 t
->integrity_supported
= true;
1219 * Prepares the table for use by building the indices,
1220 * setting the type, and allocating mempools.
1222 int dm_table_complete(struct dm_table
*t
)
1226 r
= dm_table_determine_type(t
);
1228 DMERR("unable to determine table type");
1232 r
= dm_table_build_index(t
);
1234 DMERR("unable to build btrees");
1238 r
= dm_table_register_integrity(t
);
1240 DMERR("could not register integrity profile.");
1244 r
= dm_table_alloc_md_mempools(t
, t
->md
);
1246 DMERR("unable to allocate mempools");
1251 static DEFINE_MUTEX(_event_lock
);
1252 void dm_table_event_callback(struct dm_table
*t
,
1253 void (*fn
)(void *), void *context
)
1255 mutex_lock(&_event_lock
);
1257 t
->event_context
= context
;
1258 mutex_unlock(&_event_lock
);
1261 void dm_table_event(struct dm_table
*t
)
1264 * You can no longer call dm_table_event() from interrupt
1265 * context, use a bottom half instead.
1267 BUG_ON(in_interrupt());
1269 mutex_lock(&_event_lock
);
1271 t
->event_fn(t
->event_context
);
1272 mutex_unlock(&_event_lock
);
1274 EXPORT_SYMBOL(dm_table_event
);
1276 sector_t
dm_table_get_size(struct dm_table
*t
)
1278 return t
->num_targets
? (t
->highs
[t
->num_targets
- 1] + 1) : 0;
1280 EXPORT_SYMBOL(dm_table_get_size
);
1282 struct dm_target
*dm_table_get_target(struct dm_table
*t
, unsigned int index
)
1284 if (index
>= t
->num_targets
)
1287 return t
->targets
+ index
;
1291 * Search the btree for the correct target.
1293 * Caller should check returned pointer with dm_target_is_valid()
1294 * to trap I/O beyond end of device.
1296 struct dm_target
*dm_table_find_target(struct dm_table
*t
, sector_t sector
)
1298 unsigned int l
, n
= 0, k
= 0;
1301 for (l
= 0; l
< t
->depth
; l
++) {
1302 n
= get_child(n
, k
);
1303 node
= get_node(t
, l
, n
);
1305 for (k
= 0; k
< KEYS_PER_NODE
; k
++)
1306 if (node
[k
] >= sector
)
1310 return &t
->targets
[(KEYS_PER_NODE
* n
) + k
];
1313 static int count_device(struct dm_target
*ti
, struct dm_dev
*dev
,
1314 sector_t start
, sector_t len
, void *data
)
1316 unsigned *num_devices
= data
;
1324 * Check whether a table has no data devices attached using each
1325 * target's iterate_devices method.
1326 * Returns false if the result is unknown because a target doesn't
1327 * support iterate_devices.
1329 bool dm_table_has_no_data_devices(struct dm_table
*table
)
1331 struct dm_target
*ti
;
1332 unsigned i
, num_devices
;
1334 for (i
= 0; i
< dm_table_get_num_targets(table
); i
++) {
1335 ti
= dm_table_get_target(table
, i
);
1337 if (!ti
->type
->iterate_devices
)
1341 ti
->type
->iterate_devices(ti
, count_device
, &num_devices
);
1350 * Establish the new table's queue_limits and validate them.
1352 int dm_calculate_queue_limits(struct dm_table
*table
,
1353 struct queue_limits
*limits
)
1355 struct dm_target
*ti
;
1356 struct queue_limits ti_limits
;
1359 blk_set_stacking_limits(limits
);
1361 for (i
= 0; i
< dm_table_get_num_targets(table
); i
++) {
1362 blk_set_stacking_limits(&ti_limits
);
1364 ti
= dm_table_get_target(table
, i
);
1366 if (!ti
->type
->iterate_devices
)
1367 goto combine_limits
;
1370 * Combine queue limits of all the devices this target uses.
1372 ti
->type
->iterate_devices(ti
, dm_set_device_limits
,
1375 /* Set I/O hints portion of queue limits */
1376 if (ti
->type
->io_hints
)
1377 ti
->type
->io_hints(ti
, &ti_limits
);
1380 * Check each device area is consistent with the target's
1381 * overall queue limits.
1383 if (ti
->type
->iterate_devices(ti
, device_area_is_invalid
,
1389 * Merge this target's queue limits into the overall limits
1392 if (blk_stack_limits(limits
, &ti_limits
, 0) < 0)
1393 DMWARN("%s: adding target device "
1394 "(start sect %llu len %llu) "
1395 "caused an alignment inconsistency",
1396 dm_device_name(table
->md
),
1397 (unsigned long long) ti
->begin
,
1398 (unsigned long long) ti
->len
);
1401 return validate_hardware_logical_block_alignment(table
, limits
);
1405 * Verify that all devices have an integrity profile that matches the
1406 * DM device's registered integrity profile. If the profiles don't
1407 * match then unregister the DM device's integrity profile.
1409 static void dm_table_verify_integrity(struct dm_table
*t
)
1411 struct gendisk
*template_disk
= NULL
;
1413 if (t
->integrity_added
)
1416 if (t
->integrity_supported
) {
1418 * Verify that the original integrity profile
1419 * matches all the devices in this table.
1421 template_disk
= dm_table_get_integrity_disk(t
);
1422 if (template_disk
&&
1423 blk_integrity_compare(dm_disk(t
->md
), template_disk
) >= 0)
1427 if (integrity_profile_exists(dm_disk(t
->md
))) {
1428 DMWARN("%s: unable to establish an integrity profile",
1429 dm_device_name(t
->md
));
1430 blk_integrity_unregister(dm_disk(t
->md
));
1434 static int device_flush_capable(struct dm_target
*ti
, struct dm_dev
*dev
,
1435 sector_t start
, sector_t len
, void *data
)
1437 unsigned long flush
= (unsigned long) data
;
1438 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1440 return q
&& (q
->queue_flags
& flush
);
1443 static bool dm_table_supports_flush(struct dm_table
*t
, unsigned long flush
)
1445 struct dm_target
*ti
;
1449 * Require at least one underlying device to support flushes.
1450 * t->devices includes internal dm devices such as mirror logs
1451 * so we need to use iterate_devices here, which targets
1452 * supporting flushes must provide.
1454 for (i
= 0; i
< dm_table_get_num_targets(t
); i
++) {
1455 ti
= dm_table_get_target(t
, i
);
1457 if (!ti
->num_flush_bios
)
1460 if (ti
->flush_supported
)
1463 if (ti
->type
->iterate_devices
&&
1464 ti
->type
->iterate_devices(ti
, device_flush_capable
, (void *) flush
))
1471 static int device_is_nonrot(struct dm_target
*ti
, struct dm_dev
*dev
,
1472 sector_t start
, sector_t len
, void *data
)
1474 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1476 return q
&& blk_queue_nonrot(q
);
1479 static int device_is_not_random(struct dm_target
*ti
, struct dm_dev
*dev
,
1480 sector_t start
, sector_t len
, void *data
)
1482 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1484 return q
&& !blk_queue_add_random(q
);
1487 static int queue_supports_sg_merge(struct dm_target
*ti
, struct dm_dev
*dev
,
1488 sector_t start
, sector_t len
, void *data
)
1490 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1492 return q
&& !test_bit(QUEUE_FLAG_NO_SG_MERGE
, &q
->queue_flags
);
1495 static bool dm_table_all_devices_attribute(struct dm_table
*t
,
1496 iterate_devices_callout_fn func
)
1498 struct dm_target
*ti
;
1501 for (i
= 0; i
< dm_table_get_num_targets(t
); i
++) {
1502 ti
= dm_table_get_target(t
, i
);
1504 if (!ti
->type
->iterate_devices
||
1505 !ti
->type
->iterate_devices(ti
, func
, NULL
))
1512 static int device_not_write_same_capable(struct dm_target
*ti
, struct dm_dev
*dev
,
1513 sector_t start
, sector_t len
, void *data
)
1515 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1517 return q
&& !q
->limits
.max_write_same_sectors
;
1520 static bool dm_table_supports_write_same(struct dm_table
*t
)
1522 struct dm_target
*ti
;
1525 for (i
= 0; i
< dm_table_get_num_targets(t
); i
++) {
1526 ti
= dm_table_get_target(t
, i
);
1528 if (!ti
->num_write_same_bios
)
1531 if (!ti
->type
->iterate_devices
||
1532 ti
->type
->iterate_devices(ti
, device_not_write_same_capable
, NULL
))
1539 static int device_not_write_zeroes_capable(struct dm_target
*ti
, struct dm_dev
*dev
,
1540 sector_t start
, sector_t len
, void *data
)
1542 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1544 return q
&& !q
->limits
.max_write_zeroes_sectors
;
1547 static bool dm_table_supports_write_zeroes(struct dm_table
*t
)
1549 struct dm_target
*ti
;
1552 while (i
< dm_table_get_num_targets(t
)) {
1553 ti
= dm_table_get_target(t
, i
++);
1555 if (!ti
->num_write_zeroes_bios
)
1558 if (!ti
->type
->iterate_devices
||
1559 ti
->type
->iterate_devices(ti
, device_not_write_zeroes_capable
, NULL
))
1567 static int device_discard_capable(struct dm_target
*ti
, struct dm_dev
*dev
,
1568 sector_t start
, sector_t len
, void *data
)
1570 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1572 return q
&& blk_queue_discard(q
);
1575 static bool dm_table_supports_discards(struct dm_table
*t
)
1577 struct dm_target
*ti
;
1581 * Unless any target used by the table set discards_supported,
1582 * require at least one underlying device to support discards.
1583 * t->devices includes internal dm devices such as mirror logs
1584 * so we need to use iterate_devices here, which targets
1585 * supporting discard selectively must provide.
1587 for (i
= 0; i
< dm_table_get_num_targets(t
); i
++) {
1588 ti
= dm_table_get_target(t
, i
);
1590 if (!ti
->num_discard_bios
)
1593 if (ti
->discards_supported
)
1596 if (ti
->type
->iterate_devices
&&
1597 ti
->type
->iterate_devices(ti
, device_discard_capable
, NULL
))
1604 void dm_table_set_restrictions(struct dm_table
*t
, struct request_queue
*q
,
1605 struct queue_limits
*limits
)
1607 bool wc
= false, fua
= false;
1610 * Copy table's limits to the DM device's request_queue
1612 q
->limits
= *limits
;
1614 if (!dm_table_supports_discards(t
))
1615 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD
, q
);
1617 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
, q
);
1619 if (dm_table_supports_flush(t
, (1UL << QUEUE_FLAG_WC
))) {
1621 if (dm_table_supports_flush(t
, (1UL << QUEUE_FLAG_FUA
)))
1624 blk_queue_write_cache(q
, wc
, fua
);
1626 /* Ensure that all underlying devices are non-rotational. */
1627 if (dm_table_all_devices_attribute(t
, device_is_nonrot
))
1628 queue_flag_set_unlocked(QUEUE_FLAG_NONROT
, q
);
1630 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT
, q
);
1632 if (!dm_table_supports_write_same(t
))
1633 q
->limits
.max_write_same_sectors
= 0;
1634 if (!dm_table_supports_write_zeroes(t
))
1635 q
->limits
.max_write_zeroes_sectors
= 0;
1637 if (dm_table_all_devices_attribute(t
, queue_supports_sg_merge
))
1638 queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE
, q
);
1640 queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE
, q
);
1642 dm_table_verify_integrity(t
);
1645 * Determine whether or not this queue's I/O timings contribute
1646 * to the entropy pool, Only request-based targets use this.
1647 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1650 if (blk_queue_add_random(q
) && dm_table_all_devices_attribute(t
, device_is_not_random
))
1651 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM
, q
);
1654 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1655 * visible to other CPUs because, once the flag is set, incoming bios
1656 * are processed by request-based dm, which refers to the queue
1658 * Until the flag set, bios are passed to bio-based dm and queued to
1659 * md->deferred where queue settings are not needed yet.
1660 * Those bios are passed to request-based dm at the resume time.
1663 if (dm_table_request_based(t
))
1664 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE
, q
);
1667 unsigned int dm_table_get_num_targets(struct dm_table
*t
)
1669 return t
->num_targets
;
1672 struct list_head
*dm_table_get_devices(struct dm_table
*t
)
1677 fmode_t
dm_table_get_mode(struct dm_table
*t
)
1681 EXPORT_SYMBOL(dm_table_get_mode
);
1689 static void suspend_targets(struct dm_table
*t
, enum suspend_mode mode
)
1691 int i
= t
->num_targets
;
1692 struct dm_target
*ti
= t
->targets
;
1694 lockdep_assert_held(&t
->md
->suspend_lock
);
1699 if (ti
->type
->presuspend
)
1700 ti
->type
->presuspend(ti
);
1702 case PRESUSPEND_UNDO
:
1703 if (ti
->type
->presuspend_undo
)
1704 ti
->type
->presuspend_undo(ti
);
1707 if (ti
->type
->postsuspend
)
1708 ti
->type
->postsuspend(ti
);
1715 void dm_table_presuspend_targets(struct dm_table
*t
)
1720 suspend_targets(t
, PRESUSPEND
);
1723 void dm_table_presuspend_undo_targets(struct dm_table
*t
)
1728 suspend_targets(t
, PRESUSPEND_UNDO
);
1731 void dm_table_postsuspend_targets(struct dm_table
*t
)
1736 suspend_targets(t
, POSTSUSPEND
);
1739 int dm_table_resume_targets(struct dm_table
*t
)
1743 lockdep_assert_held(&t
->md
->suspend_lock
);
1745 for (i
= 0; i
< t
->num_targets
; i
++) {
1746 struct dm_target
*ti
= t
->targets
+ i
;
1748 if (!ti
->type
->preresume
)
1751 r
= ti
->type
->preresume(ti
);
1753 DMERR("%s: %s: preresume failed, error = %d",
1754 dm_device_name(t
->md
), ti
->type
->name
, r
);
1759 for (i
= 0; i
< t
->num_targets
; i
++) {
1760 struct dm_target
*ti
= t
->targets
+ i
;
1762 if (ti
->type
->resume
)
1763 ti
->type
->resume(ti
);
1769 void dm_table_add_target_callbacks(struct dm_table
*t
, struct dm_target_callbacks
*cb
)
1771 list_add(&cb
->list
, &t
->target_callbacks
);
1773 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks
);
1775 int dm_table_any_congested(struct dm_table
*t
, int bdi_bits
)
1777 struct dm_dev_internal
*dd
;
1778 struct list_head
*devices
= dm_table_get_devices(t
);
1779 struct dm_target_callbacks
*cb
;
1782 list_for_each_entry(dd
, devices
, list
) {
1783 struct request_queue
*q
= bdev_get_queue(dd
->dm_dev
->bdev
);
1784 char b
[BDEVNAME_SIZE
];
1787 r
|= bdi_congested(q
->backing_dev_info
, bdi_bits
);
1789 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1790 dm_device_name(t
->md
),
1791 bdevname(dd
->dm_dev
->bdev
, b
));
1794 list_for_each_entry(cb
, &t
->target_callbacks
, list
)
1795 if (cb
->congested_fn
)
1796 r
|= cb
->congested_fn(cb
, bdi_bits
);
1801 struct mapped_device
*dm_table_get_md(struct dm_table
*t
)
1805 EXPORT_SYMBOL(dm_table_get_md
);
1807 void dm_table_run_md_queue_async(struct dm_table
*t
)
1809 struct mapped_device
*md
;
1810 struct request_queue
*queue
;
1811 unsigned long flags
;
1813 if (!dm_table_request_based(t
))
1816 md
= dm_table_get_md(t
);
1817 queue
= dm_get_md_queue(md
);
1820 blk_mq_run_hw_queues(queue
, true);
1822 spin_lock_irqsave(queue
->queue_lock
, flags
);
1823 blk_run_queue_async(queue
);
1824 spin_unlock_irqrestore(queue
->queue_lock
, flags
);
1828 EXPORT_SYMBOL(dm_table_run_md_queue_async
);