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>
22 #define DM_MSG_PREFIX "table"
25 #define NODE_SIZE L1_CACHE_BYTES
26 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
27 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
30 * The table has always exactly one reference from either mapped_device->map
31 * or hash_cell->new_map. This reference is not counted in table->holders.
32 * A pair of dm_create_table/dm_destroy_table functions is used for table
33 * creation/destruction.
35 * Temporary references from the other code increase table->holders. A pair
36 * of dm_table_get/dm_table_put functions is used to manipulate it.
38 * When the table is about to be destroyed, we wait for table->holders to
43 struct mapped_device
*md
;
49 unsigned int counts
[MAX_DEPTH
]; /* in nodes */
50 sector_t
*index
[MAX_DEPTH
];
52 unsigned int num_targets
;
53 unsigned int num_allocated
;
55 struct dm_target
*targets
;
57 struct target_type
*immutable_target_type
;
58 unsigned integrity_supported
:1;
62 * Indicates the rw permissions for the new logical
63 * device. This should be a combination of FMODE_READ
68 /* a list of devices used by this table */
69 struct list_head devices
;
71 /* events get handed up using this callback */
72 void (*event_fn
)(void *);
75 struct dm_md_mempools
*mempools
;
77 struct list_head target_callbacks
;
81 * Similar to ceiling(log_size(n))
83 static unsigned int int_log(unsigned int n
, unsigned int base
)
88 n
= dm_div_up(n
, base
);
96 * Calculate the index of the child node of the n'th node k'th key.
98 static inline unsigned int get_child(unsigned int n
, unsigned int k
)
100 return (n
* CHILDREN_PER_NODE
) + k
;
104 * Return the n'th node of level l from table t.
106 static inline sector_t
*get_node(struct dm_table
*t
,
107 unsigned int l
, unsigned int n
)
109 return t
->index
[l
] + (n
* KEYS_PER_NODE
);
113 * Return the highest key that you could lookup from the n'th
114 * node on level l of the btree.
116 static sector_t
high(struct dm_table
*t
, unsigned int l
, unsigned int n
)
118 for (; l
< t
->depth
- 1; l
++)
119 n
= get_child(n
, CHILDREN_PER_NODE
- 1);
121 if (n
>= t
->counts
[l
])
122 return (sector_t
) - 1;
124 return get_node(t
, l
, n
)[KEYS_PER_NODE
- 1];
128 * Fills in a level of the btree based on the highs of the level
131 static int setup_btree_index(unsigned int l
, struct dm_table
*t
)
136 for (n
= 0U; n
< t
->counts
[l
]; n
++) {
137 node
= get_node(t
, l
, n
);
139 for (k
= 0U; k
< KEYS_PER_NODE
; k
++)
140 node
[k
] = high(t
, l
+ 1, get_child(n
, k
));
146 void *dm_vcalloc(unsigned long nmemb
, unsigned long elem_size
)
152 * Check that we're not going to overflow.
154 if (nmemb
> (ULONG_MAX
/ elem_size
))
157 size
= nmemb
* elem_size
;
158 addr
= vzalloc(size
);
162 EXPORT_SYMBOL(dm_vcalloc
);
165 * highs, and targets are managed as dynamic arrays during a
168 static int alloc_targets(struct dm_table
*t
, unsigned int num
)
171 struct dm_target
*n_targets
;
172 int n
= t
->num_targets
;
175 * Allocate both the target array and offset array at once.
176 * Append an empty entry to catch sectors beyond the end of
179 n_highs
= (sector_t
*) dm_vcalloc(num
+ 1, sizeof(struct dm_target
) +
184 n_targets
= (struct dm_target
*) (n_highs
+ num
);
187 memcpy(n_highs
, t
->highs
, sizeof(*n_highs
) * n
);
188 memcpy(n_targets
, t
->targets
, sizeof(*n_targets
) * n
);
191 memset(n_highs
+ n
, -1, sizeof(*n_highs
) * (num
- n
));
194 t
->num_allocated
= num
;
196 t
->targets
= n_targets
;
201 int dm_table_create(struct dm_table
**result
, fmode_t mode
,
202 unsigned num_targets
, struct mapped_device
*md
)
204 struct dm_table
*t
= kzalloc(sizeof(*t
), GFP_KERNEL
);
209 INIT_LIST_HEAD(&t
->devices
);
210 INIT_LIST_HEAD(&t
->target_callbacks
);
211 atomic_set(&t
->holders
, 0);
214 num_targets
= KEYS_PER_NODE
;
216 num_targets
= dm_round_up(num_targets
, KEYS_PER_NODE
);
223 if (alloc_targets(t
, num_targets
)) {
234 static void free_devices(struct list_head
*devices
)
236 struct list_head
*tmp
, *next
;
238 list_for_each_safe(tmp
, next
, devices
) {
239 struct dm_dev_internal
*dd
=
240 list_entry(tmp
, struct dm_dev_internal
, list
);
241 DMWARN("dm_table_destroy: dm_put_device call missing for %s",
247 void dm_table_destroy(struct dm_table
*t
)
254 while (atomic_read(&t
->holders
))
258 /* free the indexes */
260 vfree(t
->index
[t
->depth
- 2]);
262 /* free the targets */
263 for (i
= 0; i
< t
->num_targets
; i
++) {
264 struct dm_target
*tgt
= t
->targets
+ i
;
269 dm_put_target_type(tgt
->type
);
274 /* free the device list */
275 free_devices(&t
->devices
);
277 dm_free_md_mempools(t
->mempools
);
282 void dm_table_get(struct dm_table
*t
)
284 atomic_inc(&t
->holders
);
286 EXPORT_SYMBOL(dm_table_get
);
288 void dm_table_put(struct dm_table
*t
)
293 smp_mb__before_atomic_dec();
294 atomic_dec(&t
->holders
);
296 EXPORT_SYMBOL(dm_table_put
);
299 * Checks to see if we need to extend highs or targets.
301 static inline int check_space(struct dm_table
*t
)
303 if (t
->num_targets
>= t
->num_allocated
)
304 return alloc_targets(t
, t
->num_allocated
* 2);
310 * See if we've already got a device in the list.
312 static struct dm_dev_internal
*find_device(struct list_head
*l
, dev_t dev
)
314 struct dm_dev_internal
*dd
;
316 list_for_each_entry (dd
, l
, list
)
317 if (dd
->dm_dev
.bdev
->bd_dev
== dev
)
324 * Open a device so we can use it as a map destination.
326 static int open_dev(struct dm_dev_internal
*d
, dev_t dev
,
327 struct mapped_device
*md
)
329 static char *_claim_ptr
= "I belong to device-mapper";
330 struct block_device
*bdev
;
334 BUG_ON(d
->dm_dev
.bdev
);
336 bdev
= blkdev_get_by_dev(dev
, d
->dm_dev
.mode
| FMODE_EXCL
, _claim_ptr
);
338 return PTR_ERR(bdev
);
340 r
= bd_link_disk_holder(bdev
, dm_disk(md
));
342 blkdev_put(bdev
, d
->dm_dev
.mode
| FMODE_EXCL
);
346 d
->dm_dev
.bdev
= bdev
;
351 * Close a device that we've been using.
353 static void close_dev(struct dm_dev_internal
*d
, struct mapped_device
*md
)
358 bd_unlink_disk_holder(d
->dm_dev
.bdev
, dm_disk(md
));
359 blkdev_put(d
->dm_dev
.bdev
, d
->dm_dev
.mode
| FMODE_EXCL
);
360 d
->dm_dev
.bdev
= NULL
;
364 * If possible, this checks an area of a destination device is invalid.
366 static int device_area_is_invalid(struct dm_target
*ti
, struct dm_dev
*dev
,
367 sector_t start
, sector_t len
, void *data
)
369 struct request_queue
*q
;
370 struct queue_limits
*limits
= data
;
371 struct block_device
*bdev
= dev
->bdev
;
373 i_size_read(bdev
->bd_inode
) >> SECTOR_SHIFT
;
374 unsigned short logical_block_size_sectors
=
375 limits
->logical_block_size
>> SECTOR_SHIFT
;
376 char b
[BDEVNAME_SIZE
];
379 * Some devices exist without request functions,
380 * such as loop devices not yet bound to backing files.
381 * Forbid the use of such devices.
383 q
= bdev_get_queue(bdev
);
384 if (!q
|| !q
->make_request_fn
) {
385 DMWARN("%s: %s is not yet initialised: "
386 "start=%llu, len=%llu, dev_size=%llu",
387 dm_device_name(ti
->table
->md
), bdevname(bdev
, b
),
388 (unsigned long long)start
,
389 (unsigned long long)len
,
390 (unsigned long long)dev_size
);
397 if ((start
>= dev_size
) || (start
+ len
> dev_size
)) {
398 DMWARN("%s: %s too small for target: "
399 "start=%llu, len=%llu, dev_size=%llu",
400 dm_device_name(ti
->table
->md
), bdevname(bdev
, b
),
401 (unsigned long long)start
,
402 (unsigned long long)len
,
403 (unsigned long long)dev_size
);
407 if (logical_block_size_sectors
<= 1)
410 if (start
& (logical_block_size_sectors
- 1)) {
411 DMWARN("%s: start=%llu not aligned to h/w "
412 "logical block size %u of %s",
413 dm_device_name(ti
->table
->md
),
414 (unsigned long long)start
,
415 limits
->logical_block_size
, bdevname(bdev
, b
));
419 if (len
& (logical_block_size_sectors
- 1)) {
420 DMWARN("%s: len=%llu not aligned to h/w "
421 "logical block size %u of %s",
422 dm_device_name(ti
->table
->md
),
423 (unsigned long long)len
,
424 limits
->logical_block_size
, bdevname(bdev
, b
));
432 * This upgrades the mode on an already open dm_dev, being
433 * careful to leave things as they were if we fail to reopen the
434 * device and not to touch the existing bdev field in case
435 * it is accessed concurrently inside dm_table_any_congested().
437 static int upgrade_mode(struct dm_dev_internal
*dd
, fmode_t new_mode
,
438 struct mapped_device
*md
)
441 struct dm_dev_internal dd_new
, dd_old
;
443 dd_new
= dd_old
= *dd
;
445 dd_new
.dm_dev
.mode
|= new_mode
;
446 dd_new
.dm_dev
.bdev
= NULL
;
448 r
= open_dev(&dd_new
, dd
->dm_dev
.bdev
->bd_dev
, md
);
452 dd
->dm_dev
.mode
|= new_mode
;
453 close_dev(&dd_old
, md
);
459 * Add a device to the list, or just increment the usage count if
460 * it's already present.
462 int dm_get_device(struct dm_target
*ti
, const char *path
, fmode_t mode
,
463 struct dm_dev
**result
)
466 dev_t
uninitialized_var(dev
);
467 struct dm_dev_internal
*dd
;
468 unsigned int major
, minor
;
469 struct dm_table
*t
= ti
->table
;
474 if (sscanf(path
, "%u:%u%c", &major
, &minor
, &dummy
) == 2) {
475 /* Extract the major/minor numbers */
476 dev
= MKDEV(major
, minor
);
477 if (MAJOR(dev
) != major
|| MINOR(dev
) != minor
)
480 /* convert the path to a device */
481 struct block_device
*bdev
= lookup_bdev(path
);
484 return PTR_ERR(bdev
);
489 dd
= find_device(&t
->devices
, dev
);
491 dd
= kmalloc(sizeof(*dd
), GFP_KERNEL
);
495 dd
->dm_dev
.mode
= mode
;
496 dd
->dm_dev
.bdev
= NULL
;
498 if ((r
= open_dev(dd
, dev
, t
->md
))) {
503 format_dev_t(dd
->dm_dev
.name
, dev
);
505 atomic_set(&dd
->count
, 0);
506 list_add(&dd
->list
, &t
->devices
);
508 } else if (dd
->dm_dev
.mode
!= (mode
| dd
->dm_dev
.mode
)) {
509 r
= upgrade_mode(dd
, mode
, t
->md
);
513 atomic_inc(&dd
->count
);
515 *result
= &dd
->dm_dev
;
518 EXPORT_SYMBOL(dm_get_device
);
520 int dm_set_device_limits(struct dm_target
*ti
, struct dm_dev
*dev
,
521 sector_t start
, sector_t len
, void *data
)
523 struct queue_limits
*limits
= data
;
524 struct block_device
*bdev
= dev
->bdev
;
525 struct request_queue
*q
= bdev_get_queue(bdev
);
526 char b
[BDEVNAME_SIZE
];
529 DMWARN("%s: Cannot set limits for nonexistent device %s",
530 dm_device_name(ti
->table
->md
), bdevname(bdev
, b
));
534 if (bdev_stack_limits(limits
, bdev
, start
) < 0)
535 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
536 "physical_block_size=%u, logical_block_size=%u, "
537 "alignment_offset=%u, start=%llu",
538 dm_device_name(ti
->table
->md
), bdevname(bdev
, b
),
539 q
->limits
.physical_block_size
,
540 q
->limits
.logical_block_size
,
541 q
->limits
.alignment_offset
,
542 (unsigned long long) start
<< SECTOR_SHIFT
);
545 * Check if merge fn is supported.
546 * If not we'll force DM to use PAGE_SIZE or
547 * smaller I/O, just to be safe.
549 if (dm_queue_merge_is_compulsory(q
) && !ti
->type
->merge
)
550 blk_limits_max_hw_sectors(limits
,
551 (unsigned int) (PAGE_SIZE
>> 9));
554 EXPORT_SYMBOL_GPL(dm_set_device_limits
);
557 * Decrement a device's use count and remove it if necessary.
559 void dm_put_device(struct dm_target
*ti
, struct dm_dev
*d
)
561 struct dm_dev_internal
*dd
= container_of(d
, struct dm_dev_internal
,
564 if (atomic_dec_and_test(&dd
->count
)) {
565 close_dev(dd
, ti
->table
->md
);
570 EXPORT_SYMBOL(dm_put_device
);
573 * Checks to see if the target joins onto the end of the table.
575 static int adjoin(struct dm_table
*table
, struct dm_target
*ti
)
577 struct dm_target
*prev
;
579 if (!table
->num_targets
)
582 prev
= &table
->targets
[table
->num_targets
- 1];
583 return (ti
->begin
== (prev
->begin
+ prev
->len
));
587 * Used to dynamically allocate the arg array.
589 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
590 * process messages even if some device is suspended. These messages have a
591 * small fixed number of arguments.
593 * On the other hand, dm-switch needs to process bulk data using messages and
594 * excessive use of GFP_NOIO could cause trouble.
596 static char **realloc_argv(unsigned *array_size
, char **old_argv
)
603 new_size
= *array_size
* 2;
609 argv
= kmalloc(new_size
* sizeof(*argv
), gfp
);
611 memcpy(argv
, old_argv
, *array_size
* sizeof(*argv
));
612 *array_size
= new_size
;
620 * Destructively splits up the argument list to pass to ctr.
622 int dm_split_args(int *argc
, char ***argvp
, char *input
)
624 char *start
, *end
= input
, *out
, **argv
= NULL
;
625 unsigned array_size
= 0;
634 argv
= realloc_argv(&array_size
, argv
);
639 /* Skip whitespace */
640 start
= skip_spaces(end
);
643 break; /* success, we hit the end */
645 /* 'out' is used to remove any back-quotes */
648 /* Everything apart from '\0' can be quoted */
649 if (*end
== '\\' && *(end
+ 1)) {
656 break; /* end of token */
661 /* have we already filled the array ? */
662 if ((*argc
+ 1) > array_size
) {
663 argv
= realloc_argv(&array_size
, argv
);
668 /* we know this is whitespace */
672 /* terminate the string and put it in the array */
683 * Impose necessary and sufficient conditions on a devices's table such
684 * that any incoming bio which respects its logical_block_size can be
685 * processed successfully. If it falls across the boundary between
686 * two or more targets, the size of each piece it gets split into must
687 * be compatible with the logical_block_size of the target processing it.
689 static int validate_hardware_logical_block_alignment(struct dm_table
*table
,
690 struct queue_limits
*limits
)
693 * This function uses arithmetic modulo the logical_block_size
694 * (in units of 512-byte sectors).
696 unsigned short device_logical_block_size_sects
=
697 limits
->logical_block_size
>> SECTOR_SHIFT
;
700 * Offset of the start of the next table entry, mod logical_block_size.
702 unsigned short next_target_start
= 0;
705 * Given an aligned bio that extends beyond the end of a
706 * target, how many sectors must the next target handle?
708 unsigned short remaining
= 0;
710 struct dm_target
*uninitialized_var(ti
);
711 struct queue_limits ti_limits
;
715 * Check each entry in the table in turn.
717 while (i
< dm_table_get_num_targets(table
)) {
718 ti
= dm_table_get_target(table
, i
++);
720 blk_set_stacking_limits(&ti_limits
);
722 /* combine all target devices' limits */
723 if (ti
->type
->iterate_devices
)
724 ti
->type
->iterate_devices(ti
, dm_set_device_limits
,
728 * If the remaining sectors fall entirely within this
729 * table entry are they compatible with its logical_block_size?
731 if (remaining
< ti
->len
&&
732 remaining
& ((ti_limits
.logical_block_size
>>
737 (unsigned short) ((next_target_start
+ ti
->len
) &
738 (device_logical_block_size_sects
- 1));
739 remaining
= next_target_start
?
740 device_logical_block_size_sects
- next_target_start
: 0;
744 DMWARN("%s: table line %u (start sect %llu len %llu) "
745 "not aligned to h/w logical block size %u",
746 dm_device_name(table
->md
), i
,
747 (unsigned long long) ti
->begin
,
748 (unsigned long long) ti
->len
,
749 limits
->logical_block_size
);
756 int dm_table_add_target(struct dm_table
*t
, const char *type
,
757 sector_t start
, sector_t len
, char *params
)
759 int r
= -EINVAL
, argc
;
761 struct dm_target
*tgt
;
764 DMERR("%s: target type %s must appear alone in table",
765 dm_device_name(t
->md
), t
->targets
->type
->name
);
769 if ((r
= check_space(t
)))
772 tgt
= t
->targets
+ t
->num_targets
;
773 memset(tgt
, 0, sizeof(*tgt
));
776 DMERR("%s: zero-length target", dm_device_name(t
->md
));
780 tgt
->type
= dm_get_target_type(type
);
782 DMERR("%s: %s: unknown target type", dm_device_name(t
->md
),
787 if (dm_target_needs_singleton(tgt
->type
)) {
788 if (t
->num_targets
) {
789 DMERR("%s: target type %s must appear alone in table",
790 dm_device_name(t
->md
), type
);
796 if (dm_target_always_writeable(tgt
->type
) && !(t
->mode
& FMODE_WRITE
)) {
797 DMERR("%s: target type %s may not be included in read-only tables",
798 dm_device_name(t
->md
), type
);
802 if (t
->immutable_target_type
) {
803 if (t
->immutable_target_type
!= tgt
->type
) {
804 DMERR("%s: immutable target type %s cannot be mixed with other target types",
805 dm_device_name(t
->md
), t
->immutable_target_type
->name
);
808 } else if (dm_target_is_immutable(tgt
->type
)) {
809 if (t
->num_targets
) {
810 DMERR("%s: immutable target type %s cannot be mixed with other target types",
811 dm_device_name(t
->md
), tgt
->type
->name
);
814 t
->immutable_target_type
= tgt
->type
;
820 tgt
->error
= "Unknown error";
823 * Does this target adjoin the previous one ?
825 if (!adjoin(t
, tgt
)) {
826 tgt
->error
= "Gap in table";
831 r
= dm_split_args(&argc
, &argv
, params
);
833 tgt
->error
= "couldn't split parameters (insufficient memory)";
837 r
= tgt
->type
->ctr(tgt
, argc
, argv
);
842 t
->highs
[t
->num_targets
++] = tgt
->begin
+ tgt
->len
- 1;
844 if (!tgt
->num_discard_bios
&& tgt
->discards_supported
)
845 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
846 dm_device_name(t
->md
), type
);
851 DMERR("%s: %s: %s", dm_device_name(t
->md
), type
, tgt
->error
);
852 dm_put_target_type(tgt
->type
);
857 * Target argument parsing helpers.
859 static int validate_next_arg(struct dm_arg
*arg
, struct dm_arg_set
*arg_set
,
860 unsigned *value
, char **error
, unsigned grouped
)
862 const char *arg_str
= dm_shift_arg(arg_set
);
866 (sscanf(arg_str
, "%u%c", value
, &dummy
) != 1) ||
867 (*value
< arg
->min
) ||
868 (*value
> arg
->max
) ||
869 (grouped
&& arg_set
->argc
< *value
)) {
877 int dm_read_arg(struct dm_arg
*arg
, struct dm_arg_set
*arg_set
,
878 unsigned *value
, char **error
)
880 return validate_next_arg(arg
, arg_set
, value
, error
, 0);
882 EXPORT_SYMBOL(dm_read_arg
);
884 int dm_read_arg_group(struct dm_arg
*arg
, struct dm_arg_set
*arg_set
,
885 unsigned *value
, char **error
)
887 return validate_next_arg(arg
, arg_set
, value
, error
, 1);
889 EXPORT_SYMBOL(dm_read_arg_group
);
891 const char *dm_shift_arg(struct dm_arg_set
*as
)
904 EXPORT_SYMBOL(dm_shift_arg
);
906 void dm_consume_args(struct dm_arg_set
*as
, unsigned num_args
)
908 BUG_ON(as
->argc
< num_args
);
909 as
->argc
-= num_args
;
910 as
->argv
+= num_args
;
912 EXPORT_SYMBOL(dm_consume_args
);
914 static int dm_table_set_type(struct dm_table
*t
)
917 unsigned bio_based
= 0, request_based
= 0;
918 struct dm_target
*tgt
;
919 struct dm_dev_internal
*dd
;
920 struct list_head
*devices
;
922 for (i
= 0; i
< t
->num_targets
; i
++) {
923 tgt
= t
->targets
+ i
;
924 if (dm_target_request_based(tgt
))
929 if (bio_based
&& request_based
) {
930 DMWARN("Inconsistent table: different target types"
931 " can't be mixed up");
937 /* We must use this table as bio-based */
938 t
->type
= DM_TYPE_BIO_BASED
;
942 BUG_ON(!request_based
); /* No targets in this table */
944 /* Non-request-stackable devices can't be used for request-based dm */
945 devices
= dm_table_get_devices(t
);
946 list_for_each_entry(dd
, devices
, list
) {
947 if (!blk_queue_stackable(bdev_get_queue(dd
->dm_dev
.bdev
))) {
948 DMWARN("table load rejected: including"
949 " non-request-stackable devices");
955 * Request-based dm supports only tables that have a single target now.
956 * To support multiple targets, request splitting support is needed,
957 * and that needs lots of changes in the block-layer.
958 * (e.g. request completion process for partial completion.)
960 if (t
->num_targets
> 1) {
961 DMWARN("Request-based dm doesn't support multiple targets yet");
965 t
->type
= DM_TYPE_REQUEST_BASED
;
970 unsigned dm_table_get_type(struct dm_table
*t
)
975 struct target_type
*dm_table_get_immutable_target_type(struct dm_table
*t
)
977 return t
->immutable_target_type
;
980 bool dm_table_request_based(struct dm_table
*t
)
982 return dm_table_get_type(t
) == DM_TYPE_REQUEST_BASED
;
985 int dm_table_alloc_md_mempools(struct dm_table
*t
)
987 unsigned type
= dm_table_get_type(t
);
988 unsigned per_bio_data_size
= 0;
989 struct dm_target
*tgt
;
992 if (unlikely(type
== DM_TYPE_NONE
)) {
993 DMWARN("no table type is set, can't allocate mempools");
997 if (type
== DM_TYPE_BIO_BASED
)
998 for (i
= 0; i
< t
->num_targets
; i
++) {
999 tgt
= t
->targets
+ i
;
1000 per_bio_data_size
= max(per_bio_data_size
, tgt
->per_bio_data_size
);
1003 t
->mempools
= dm_alloc_md_mempools(type
, t
->integrity_supported
, per_bio_data_size
);
1010 void dm_table_free_md_mempools(struct dm_table
*t
)
1012 dm_free_md_mempools(t
->mempools
);
1016 struct dm_md_mempools
*dm_table_get_md_mempools(struct dm_table
*t
)
1021 static int setup_indexes(struct dm_table
*t
)
1024 unsigned int total
= 0;
1027 /* allocate the space for *all* the indexes */
1028 for (i
= t
->depth
- 2; i
>= 0; i
--) {
1029 t
->counts
[i
] = dm_div_up(t
->counts
[i
+ 1], CHILDREN_PER_NODE
);
1030 total
+= t
->counts
[i
];
1033 indexes
= (sector_t
*) dm_vcalloc(total
, (unsigned long) NODE_SIZE
);
1037 /* set up internal nodes, bottom-up */
1038 for (i
= t
->depth
- 2; i
>= 0; i
--) {
1039 t
->index
[i
] = indexes
;
1040 indexes
+= (KEYS_PER_NODE
* t
->counts
[i
]);
1041 setup_btree_index(i
, t
);
1048 * Builds the btree to index the map.
1050 static int dm_table_build_index(struct dm_table
*t
)
1053 unsigned int leaf_nodes
;
1055 /* how many indexes will the btree have ? */
1056 leaf_nodes
= dm_div_up(t
->num_targets
, KEYS_PER_NODE
);
1057 t
->depth
= 1 + int_log(leaf_nodes
, CHILDREN_PER_NODE
);
1059 /* leaf layer has already been set up */
1060 t
->counts
[t
->depth
- 1] = leaf_nodes
;
1061 t
->index
[t
->depth
- 1] = t
->highs
;
1064 r
= setup_indexes(t
);
1070 * Get a disk whose integrity profile reflects the table's profile.
1071 * If %match_all is true, all devices' profiles must match.
1072 * If %match_all is false, all devices must at least have an
1073 * allocated integrity profile; but uninitialized is ok.
1074 * Returns NULL if integrity support was inconsistent or unavailable.
1076 static struct gendisk
* dm_table_get_integrity_disk(struct dm_table
*t
,
1079 struct list_head
*devices
= dm_table_get_devices(t
);
1080 struct dm_dev_internal
*dd
= NULL
;
1081 struct gendisk
*prev_disk
= NULL
, *template_disk
= NULL
;
1083 list_for_each_entry(dd
, devices
, list
) {
1084 template_disk
= dd
->dm_dev
.bdev
->bd_disk
;
1085 if (!blk_get_integrity(template_disk
))
1087 if (!match_all
&& !blk_integrity_is_initialized(template_disk
))
1088 continue; /* skip uninitialized profiles */
1089 else if (prev_disk
&&
1090 blk_integrity_compare(prev_disk
, template_disk
) < 0)
1092 prev_disk
= template_disk
;
1095 return template_disk
;
1099 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1100 dm_device_name(t
->md
),
1101 prev_disk
->disk_name
,
1102 template_disk
->disk_name
);
1107 * Register the mapped device for blk_integrity support if
1108 * the underlying devices have an integrity profile. But all devices
1109 * may not have matching profiles (checking all devices isn't reliable
1110 * during table load because this table may use other DM device(s) which
1111 * must be resumed before they will have an initialized integity profile).
1112 * Stacked DM devices force a 2 stage integrity profile validation:
1113 * 1 - during load, validate all initialized integrity profiles match
1114 * 2 - during resume, validate all integrity profiles match
1116 static int dm_table_prealloc_integrity(struct dm_table
*t
, struct mapped_device
*md
)
1118 struct gendisk
*template_disk
= NULL
;
1120 template_disk
= dm_table_get_integrity_disk(t
, false);
1124 if (!blk_integrity_is_initialized(dm_disk(md
))) {
1125 t
->integrity_supported
= 1;
1126 return blk_integrity_register(dm_disk(md
), NULL
);
1130 * If DM device already has an initalized integrity
1131 * profile the new profile should not conflict.
1133 if (blk_integrity_is_initialized(template_disk
) &&
1134 blk_integrity_compare(dm_disk(md
), template_disk
) < 0) {
1135 DMWARN("%s: conflict with existing integrity profile: "
1136 "%s profile mismatch",
1137 dm_device_name(t
->md
),
1138 template_disk
->disk_name
);
1142 /* Preserve existing initialized integrity profile */
1143 t
->integrity_supported
= 1;
1148 * Prepares the table for use by building the indices,
1149 * setting the type, and allocating mempools.
1151 int dm_table_complete(struct dm_table
*t
)
1155 r
= dm_table_set_type(t
);
1157 DMERR("unable to set table type");
1161 r
= dm_table_build_index(t
);
1163 DMERR("unable to build btrees");
1167 r
= dm_table_prealloc_integrity(t
, t
->md
);
1169 DMERR("could not register integrity profile.");
1173 r
= dm_table_alloc_md_mempools(t
);
1175 DMERR("unable to allocate mempools");
1180 static DEFINE_MUTEX(_event_lock
);
1181 void dm_table_event_callback(struct dm_table
*t
,
1182 void (*fn
)(void *), void *context
)
1184 mutex_lock(&_event_lock
);
1186 t
->event_context
= context
;
1187 mutex_unlock(&_event_lock
);
1190 void dm_table_event(struct dm_table
*t
)
1193 * You can no longer call dm_table_event() from interrupt
1194 * context, use a bottom half instead.
1196 BUG_ON(in_interrupt());
1198 mutex_lock(&_event_lock
);
1200 t
->event_fn(t
->event_context
);
1201 mutex_unlock(&_event_lock
);
1203 EXPORT_SYMBOL(dm_table_event
);
1205 sector_t
dm_table_get_size(struct dm_table
*t
)
1207 return t
->num_targets
? (t
->highs
[t
->num_targets
- 1] + 1) : 0;
1209 EXPORT_SYMBOL(dm_table_get_size
);
1211 struct dm_target
*dm_table_get_target(struct dm_table
*t
, unsigned int index
)
1213 if (index
>= t
->num_targets
)
1216 return t
->targets
+ index
;
1220 * Search the btree for the correct target.
1222 * Caller should check returned pointer with dm_target_is_valid()
1223 * to trap I/O beyond end of device.
1225 struct dm_target
*dm_table_find_target(struct dm_table
*t
, sector_t sector
)
1227 unsigned int l
, n
= 0, k
= 0;
1230 for (l
= 0; l
< t
->depth
; l
++) {
1231 n
= get_child(n
, k
);
1232 node
= get_node(t
, l
, n
);
1234 for (k
= 0; k
< KEYS_PER_NODE
; k
++)
1235 if (node
[k
] >= sector
)
1239 return &t
->targets
[(KEYS_PER_NODE
* n
) + k
];
1242 static int count_device(struct dm_target
*ti
, struct dm_dev
*dev
,
1243 sector_t start
, sector_t len
, void *data
)
1245 unsigned *num_devices
= data
;
1253 * Check whether a table has no data devices attached using each
1254 * target's iterate_devices method.
1255 * Returns false if the result is unknown because a target doesn't
1256 * support iterate_devices.
1258 bool dm_table_has_no_data_devices(struct dm_table
*table
)
1260 struct dm_target
*uninitialized_var(ti
);
1261 unsigned i
= 0, num_devices
= 0;
1263 while (i
< dm_table_get_num_targets(table
)) {
1264 ti
= dm_table_get_target(table
, i
++);
1266 if (!ti
->type
->iterate_devices
)
1269 ti
->type
->iterate_devices(ti
, count_device
, &num_devices
);
1278 * Establish the new table's queue_limits and validate them.
1280 int dm_calculate_queue_limits(struct dm_table
*table
,
1281 struct queue_limits
*limits
)
1283 struct dm_target
*uninitialized_var(ti
);
1284 struct queue_limits ti_limits
;
1287 blk_set_stacking_limits(limits
);
1289 while (i
< dm_table_get_num_targets(table
)) {
1290 blk_set_stacking_limits(&ti_limits
);
1292 ti
= dm_table_get_target(table
, i
++);
1294 if (!ti
->type
->iterate_devices
)
1295 goto combine_limits
;
1298 * Combine queue limits of all the devices this target uses.
1300 ti
->type
->iterate_devices(ti
, dm_set_device_limits
,
1303 /* Set I/O hints portion of queue limits */
1304 if (ti
->type
->io_hints
)
1305 ti
->type
->io_hints(ti
, &ti_limits
);
1308 * Check each device area is consistent with the target's
1309 * overall queue limits.
1311 if (ti
->type
->iterate_devices(ti
, device_area_is_invalid
,
1317 * Merge this target's queue limits into the overall limits
1320 if (blk_stack_limits(limits
, &ti_limits
, 0) < 0)
1321 DMWARN("%s: adding target device "
1322 "(start sect %llu len %llu) "
1323 "caused an alignment inconsistency",
1324 dm_device_name(table
->md
),
1325 (unsigned long long) ti
->begin
,
1326 (unsigned long long) ti
->len
);
1329 return validate_hardware_logical_block_alignment(table
, limits
);
1333 * Set the integrity profile for this device if all devices used have
1334 * matching profiles. We're quite deep in the resume path but still
1335 * don't know if all devices (particularly DM devices this device
1336 * may be stacked on) have matching profiles. Even if the profiles
1337 * don't match we have no way to fail (to resume) at this point.
1339 static void dm_table_set_integrity(struct dm_table
*t
)
1341 struct gendisk
*template_disk
= NULL
;
1343 if (!blk_get_integrity(dm_disk(t
->md
)))
1346 template_disk
= dm_table_get_integrity_disk(t
, true);
1348 blk_integrity_register(dm_disk(t
->md
),
1349 blk_get_integrity(template_disk
));
1350 else if (blk_integrity_is_initialized(dm_disk(t
->md
)))
1351 DMWARN("%s: device no longer has a valid integrity profile",
1352 dm_device_name(t
->md
));
1354 DMWARN("%s: unable to establish an integrity profile",
1355 dm_device_name(t
->md
));
1358 static int device_flush_capable(struct dm_target
*ti
, struct dm_dev
*dev
,
1359 sector_t start
, sector_t len
, void *data
)
1361 unsigned flush
= (*(unsigned *)data
);
1362 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1364 return q
&& (q
->flush_flags
& flush
);
1367 static bool dm_table_supports_flush(struct dm_table
*t
, unsigned flush
)
1369 struct dm_target
*ti
;
1373 * Require at least one underlying device to support flushes.
1374 * t->devices includes internal dm devices such as mirror logs
1375 * so we need to use iterate_devices here, which targets
1376 * supporting flushes must provide.
1378 while (i
< dm_table_get_num_targets(t
)) {
1379 ti
= dm_table_get_target(t
, i
++);
1381 if (!ti
->num_flush_bios
)
1384 if (ti
->flush_supported
)
1387 if (ti
->type
->iterate_devices
&&
1388 ti
->type
->iterate_devices(ti
, device_flush_capable
, &flush
))
1395 static bool dm_table_discard_zeroes_data(struct dm_table
*t
)
1397 struct dm_target
*ti
;
1400 /* Ensure that all targets supports discard_zeroes_data. */
1401 while (i
< dm_table_get_num_targets(t
)) {
1402 ti
= dm_table_get_target(t
, i
++);
1404 if (ti
->discard_zeroes_data_unsupported
)
1411 static int device_is_nonrot(struct dm_target
*ti
, struct dm_dev
*dev
,
1412 sector_t start
, sector_t len
, void *data
)
1414 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1416 return q
&& blk_queue_nonrot(q
);
1419 static int device_is_not_random(struct dm_target
*ti
, struct dm_dev
*dev
,
1420 sector_t start
, sector_t len
, void *data
)
1422 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1424 return q
&& !blk_queue_add_random(q
);
1427 static bool dm_table_all_devices_attribute(struct dm_table
*t
,
1428 iterate_devices_callout_fn func
)
1430 struct dm_target
*ti
;
1433 while (i
< dm_table_get_num_targets(t
)) {
1434 ti
= dm_table_get_target(t
, i
++);
1436 if (!ti
->type
->iterate_devices
||
1437 !ti
->type
->iterate_devices(ti
, func
, NULL
))
1444 static int device_not_write_same_capable(struct dm_target
*ti
, struct dm_dev
*dev
,
1445 sector_t start
, sector_t len
, void *data
)
1447 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1449 return q
&& !q
->limits
.max_write_same_sectors
;
1452 static bool dm_table_supports_write_same(struct dm_table
*t
)
1454 struct dm_target
*ti
;
1457 while (i
< dm_table_get_num_targets(t
)) {
1458 ti
= dm_table_get_target(t
, i
++);
1460 if (!ti
->num_write_same_bios
)
1463 if (!ti
->type
->iterate_devices
||
1464 ti
->type
->iterate_devices(ti
, device_not_write_same_capable
, NULL
))
1471 void dm_table_set_restrictions(struct dm_table
*t
, struct request_queue
*q
,
1472 struct queue_limits
*limits
)
1477 * Copy table's limits to the DM device's request_queue
1479 q
->limits
= *limits
;
1481 if (!dm_table_supports_discards(t
))
1482 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD
, q
);
1484 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
, q
);
1486 if (dm_table_supports_flush(t
, REQ_FLUSH
)) {
1488 if (dm_table_supports_flush(t
, REQ_FUA
))
1491 blk_queue_flush(q
, flush
);
1493 if (!dm_table_discard_zeroes_data(t
))
1494 q
->limits
.discard_zeroes_data
= 0;
1496 /* Ensure that all underlying devices are non-rotational. */
1497 if (dm_table_all_devices_attribute(t
, device_is_nonrot
))
1498 queue_flag_set_unlocked(QUEUE_FLAG_NONROT
, q
);
1500 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT
, q
);
1502 if (!dm_table_supports_write_same(t
))
1503 q
->limits
.max_write_same_sectors
= 0;
1505 dm_table_set_integrity(t
);
1508 * Determine whether or not this queue's I/O timings contribute
1509 * to the entropy pool, Only request-based targets use this.
1510 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1513 if (blk_queue_add_random(q
) && dm_table_all_devices_attribute(t
, device_is_not_random
))
1514 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM
, q
);
1517 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1518 * visible to other CPUs because, once the flag is set, incoming bios
1519 * are processed by request-based dm, which refers to the queue
1521 * Until the flag set, bios are passed to bio-based dm and queued to
1522 * md->deferred where queue settings are not needed yet.
1523 * Those bios are passed to request-based dm at the resume time.
1526 if (dm_table_request_based(t
))
1527 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE
, q
);
1530 unsigned int dm_table_get_num_targets(struct dm_table
*t
)
1532 return t
->num_targets
;
1535 struct list_head
*dm_table_get_devices(struct dm_table
*t
)
1540 fmode_t
dm_table_get_mode(struct dm_table
*t
)
1544 EXPORT_SYMBOL(dm_table_get_mode
);
1546 static void suspend_targets(struct dm_table
*t
, unsigned postsuspend
)
1548 int i
= t
->num_targets
;
1549 struct dm_target
*ti
= t
->targets
;
1553 if (ti
->type
->postsuspend
)
1554 ti
->type
->postsuspend(ti
);
1555 } else if (ti
->type
->presuspend
)
1556 ti
->type
->presuspend(ti
);
1562 void dm_table_presuspend_targets(struct dm_table
*t
)
1567 suspend_targets(t
, 0);
1570 void dm_table_postsuspend_targets(struct dm_table
*t
)
1575 suspend_targets(t
, 1);
1578 int dm_table_resume_targets(struct dm_table
*t
)
1582 for (i
= 0; i
< t
->num_targets
; i
++) {
1583 struct dm_target
*ti
= t
->targets
+ i
;
1585 if (!ti
->type
->preresume
)
1588 r
= ti
->type
->preresume(ti
);
1593 for (i
= 0; i
< t
->num_targets
; i
++) {
1594 struct dm_target
*ti
= t
->targets
+ i
;
1596 if (ti
->type
->resume
)
1597 ti
->type
->resume(ti
);
1603 void dm_table_add_target_callbacks(struct dm_table
*t
, struct dm_target_callbacks
*cb
)
1605 list_add(&cb
->list
, &t
->target_callbacks
);
1607 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks
);
1609 int dm_table_any_congested(struct dm_table
*t
, int bdi_bits
)
1611 struct dm_dev_internal
*dd
;
1612 struct list_head
*devices
= dm_table_get_devices(t
);
1613 struct dm_target_callbacks
*cb
;
1616 list_for_each_entry(dd
, devices
, list
) {
1617 struct request_queue
*q
= bdev_get_queue(dd
->dm_dev
.bdev
);
1618 char b
[BDEVNAME_SIZE
];
1621 r
|= bdi_congested(&q
->backing_dev_info
, bdi_bits
);
1623 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1624 dm_device_name(t
->md
),
1625 bdevname(dd
->dm_dev
.bdev
, b
));
1628 list_for_each_entry(cb
, &t
->target_callbacks
, list
)
1629 if (cb
->congested_fn
)
1630 r
|= cb
->congested_fn(cb
, bdi_bits
);
1635 int dm_table_any_busy_target(struct dm_table
*t
)
1638 struct dm_target
*ti
;
1640 for (i
= 0; i
< t
->num_targets
; i
++) {
1641 ti
= t
->targets
+ i
;
1642 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
1649 struct mapped_device
*dm_table_get_md(struct dm_table
*t
)
1653 EXPORT_SYMBOL(dm_table_get_md
);
1655 static int device_discard_capable(struct dm_target
*ti
, struct dm_dev
*dev
,
1656 sector_t start
, sector_t len
, void *data
)
1658 struct request_queue
*q
= bdev_get_queue(dev
->bdev
);
1660 return q
&& blk_queue_discard(q
);
1663 bool dm_table_supports_discards(struct dm_table
*t
)
1665 struct dm_target
*ti
;
1669 * Unless any target used by the table set discards_supported,
1670 * require at least one underlying device to support discards.
1671 * t->devices includes internal dm devices such as mirror logs
1672 * so we need to use iterate_devices here, which targets
1673 * supporting discard selectively must provide.
1675 while (i
< dm_table_get_num_targets(t
)) {
1676 ti
= dm_table_get_target(t
, i
++);
1678 if (!ti
->num_discard_bios
)
1681 if (ti
->discards_supported
)
1684 if (ti
->type
->iterate_devices
&&
1685 ti
->type
->iterate_devices(ti
, device_discard_capable
, NULL
))