blob: e50dad0c65f4759d535b5cf81b0258a3b27066b5 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) 2001 Sistina Software (UK) Limited.
Mikulas Patockad5816872009-01-06 03:05:10 +00003 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * This file is released under the GPL.
6 */
7
8#include "dm.h"
9
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>
André Goddard Rosae7d28602009-12-14 18:01:06 -080015#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/slab.h>
17#include <linux/interrupt.h>
Arjan van de Ven48c9c272006-03-27 01:18:20 -080018#include <linux/mutex.h>
Mikulas Patockad5816872009-01-06 03:05:10 +000019#include <linux/delay.h>
Arun Sharma600634972011-07-26 16:09:06 -070020#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
Alasdair G Kergon72d94862006-06-26 00:27:35 -070022#define DM_MSG_PREFIX "table"
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#define MAX_DEPTH 16
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)
28
Mikulas Patockad5816872009-01-06 03:05:10 +000029/*
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.
34 *
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.
37 *
38 * When the table is about to be destroyed, we wait for table->holders to
39 * drop to zero.
40 */
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042struct dm_table {
Mike Anderson1134e5a2006-03-27 01:17:54 -080043 struct mapped_device *md;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 atomic_t holders;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +010045 unsigned type;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
47 /* btree table */
48 unsigned int depth;
49 unsigned int counts[MAX_DEPTH]; /* in nodes */
50 sector_t *index[MAX_DEPTH];
51
52 unsigned int num_targets;
53 unsigned int num_allocated;
54 sector_t *highs;
55 struct dm_target *targets;
56
Alasdair G Kergon36a04562011-10-31 20:19:04 +000057 struct target_type *immutable_target_type;
Martin K. Petersena91a2782011-03-17 11:11:05 +010058 unsigned integrity_supported:1;
Alasdair G Kergon3791e2f2011-10-31 20:19:00 +000059 unsigned singleton:1;
Mike Snitzer5ae89a82010-08-12 04:14:08 +010060
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 /*
62 * Indicates the rw permissions for the new logical
63 * device. This should be a combination of FMODE_READ
64 * and FMODE_WRITE.
65 */
Al Viroaeb5d722008-09-02 15:28:45 -040066 fmode_t mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
68 /* a list of devices used by this table */
69 struct list_head devices;
70
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 /* events get handed up using this callback */
72 void (*event_fn)(void *);
73 void *event_context;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +010074
75 struct dm_md_mempools *mempools;
NeilBrown9d357b02011-01-13 20:00:01 +000076
77 struct list_head target_callbacks;
Linus Torvalds1da177e2005-04-16 15:20:36 -070078};
79
80/*
81 * Similar to ceiling(log_size(n))
82 */
83static unsigned int int_log(unsigned int n, unsigned int base)
84{
85 int result = 0;
86
87 while (n > 1) {
88 n = dm_div_up(n, base);
89 result++;
90 }
91
92 return result;
93}
94
95/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 * Calculate the index of the child node of the n'th node k'th key.
97 */
98static inline unsigned int get_child(unsigned int n, unsigned int k)
99{
100 return (n * CHILDREN_PER_NODE) + k;
101}
102
103/*
104 * Return the n'th node of level l from table t.
105 */
106static inline sector_t *get_node(struct dm_table *t,
107 unsigned int l, unsigned int n)
108{
109 return t->index[l] + (n * KEYS_PER_NODE);
110}
111
112/*
113 * Return the highest key that you could lookup from the n'th
114 * node on level l of the btree.
115 */
116static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
117{
118 for (; l < t->depth - 1; l++)
119 n = get_child(n, CHILDREN_PER_NODE - 1);
120
121 if (n >= t->counts[l])
122 return (sector_t) - 1;
123
124 return get_node(t, l, n)[KEYS_PER_NODE - 1];
125}
126
127/*
128 * Fills in a level of the btree based on the highs of the level
129 * below it.
130 */
131static int setup_btree_index(unsigned int l, struct dm_table *t)
132{
133 unsigned int n, k;
134 sector_t *node;
135
136 for (n = 0U; n < t->counts[l]; n++) {
137 node = get_node(t, l, n);
138
139 for (k = 0U; k < KEYS_PER_NODE; k++)
140 node[k] = high(t, l + 1, get_child(n, k));
141 }
142
143 return 0;
144}
145
146void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
147{
148 unsigned long size;
149 void *addr;
150
151 /*
152 * Check that we're not going to overflow.
153 */
154 if (nmemb > (ULONG_MAX / elem_size))
155 return NULL;
156
157 size = nmemb * elem_size;
Joe Perchese29e65a2011-08-02 12:32:02 +0100158 addr = vzalloc(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
160 return addr;
161}
Mike Snitzer08649012011-08-02 12:32:04 +0100162EXPORT_SYMBOL(dm_vcalloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
164/*
165 * highs, and targets are managed as dynamic arrays during a
166 * table load.
167 */
168static int alloc_targets(struct dm_table *t, unsigned int num)
169{
170 sector_t *n_highs;
171 struct dm_target *n_targets;
172 int n = t->num_targets;
173
174 /*
175 * Allocate both the target array and offset array at once.
Jun'ichi Nomura512875b2007-12-13 14:15:25 +0000176 * Append an empty entry to catch sectors beyond the end of
177 * the device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 */
Jun'ichi Nomura512875b2007-12-13 14:15:25 +0000179 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 sizeof(sector_t));
181 if (!n_highs)
182 return -ENOMEM;
183
184 n_targets = (struct dm_target *) (n_highs + num);
185
186 if (n) {
187 memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
188 memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
189 }
190
191 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
192 vfree(t->highs);
193
194 t->num_allocated = num;
195 t->highs = n_highs;
196 t->targets = n_targets;
197
198 return 0;
199}
200
Al Viroaeb5d722008-09-02 15:28:45 -0400201int dm_table_create(struct dm_table **result, fmode_t mode,
Mike Anderson1134e5a2006-03-27 01:17:54 -0800202 unsigned num_targets, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203{
Dmitry Monakhov094262d2007-10-19 22:38:51 +0100204 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206 if (!t)
207 return -ENOMEM;
208
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 INIT_LIST_HEAD(&t->devices);
NeilBrown9d357b02011-01-13 20:00:01 +0000210 INIT_LIST_HEAD(&t->target_callbacks);
Mikulas Patockad5816872009-01-06 03:05:10 +0000211 atomic_set(&t->holders, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
213 if (!num_targets)
214 num_targets = KEYS_PER_NODE;
215
216 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
217
218 if (alloc_targets(t, num_targets)) {
219 kfree(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 return -ENOMEM;
221 }
222
223 t->mode = mode;
Mike Anderson1134e5a2006-03-27 01:17:54 -0800224 t->md = md;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 *result = t;
226 return 0;
227}
228
229static void free_devices(struct list_head *devices)
230{
231 struct list_head *tmp, *next;
232
Paul Jimenezafb24522008-02-08 02:09:59 +0000233 list_for_each_safe(tmp, next, devices) {
Mikulas Patocka82b15192008-10-10 13:37:09 +0100234 struct dm_dev_internal *dd =
235 list_entry(tmp, struct dm_dev_internal, list);
Jonthan Brassow1b6da752009-06-22 10:12:29 +0100236 DMWARN("dm_table_destroy: dm_put_device call missing for %s",
237 dd->dm_dev.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 kfree(dd);
239 }
240}
241
Mikulas Patockad5816872009-01-06 03:05:10 +0000242void dm_table_destroy(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243{
244 unsigned int i;
245
Alasdair G Kergona7940152009-12-10 23:52:23 +0000246 if (!t)
247 return;
248
Mikulas Patockad5816872009-01-06 03:05:10 +0000249 while (atomic_read(&t->holders))
250 msleep(1);
251 smp_mb();
252
Will Drewry26803b92010-08-12 04:14:03 +0100253 /* free the indexes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 if (t->depth >= 2)
255 vfree(t->index[t->depth - 2]);
256
257 /* free the targets */
258 for (i = 0; i < t->num_targets; i++) {
259 struct dm_target *tgt = t->targets + i;
260
261 if (tgt->type->dtr)
262 tgt->type->dtr(tgt);
263
264 dm_put_target_type(tgt->type);
265 }
266
267 vfree(t->highs);
268
269 /* free the device list */
Hannes Reinecke574ce072012-03-28 18:41:24 +0100270 free_devices(&t->devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100272 dm_free_md_mempools(t->mempools);
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 kfree(t);
275}
276
277void dm_table_get(struct dm_table *t)
278{
279 atomic_inc(&t->holders);
280}
Mike Snitzer08649012011-08-02 12:32:04 +0100281EXPORT_SYMBOL(dm_table_get);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283void dm_table_put(struct dm_table *t)
284{
285 if (!t)
286 return;
287
Mikulas Patockad5816872009-01-06 03:05:10 +0000288 smp_mb__before_atomic_dec();
289 atomic_dec(&t->holders);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290}
Mike Snitzer08649012011-08-02 12:32:04 +0100291EXPORT_SYMBOL(dm_table_put);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
293/*
294 * Checks to see if we need to extend highs or targets.
295 */
296static inline int check_space(struct dm_table *t)
297{
298 if (t->num_targets >= t->num_allocated)
299 return alloc_targets(t, t->num_allocated * 2);
300
301 return 0;
302}
303
304/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 * See if we've already got a device in the list.
306 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100307static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308{
Mikulas Patocka82b15192008-10-10 13:37:09 +0100309 struct dm_dev_internal *dd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
311 list_for_each_entry (dd, l, list)
Mikulas Patocka82b15192008-10-10 13:37:09 +0100312 if (dd->dm_dev.bdev->bd_dev == dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 return dd;
314
315 return NULL;
316}
317
318/*
319 * Open a device so we can use it as a map destination.
320 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100321static int open_dev(struct dm_dev_internal *d, dev_t dev,
322 struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323{
324 static char *_claim_ptr = "I belong to device-mapper";
325 struct block_device *bdev;
326
327 int r;
328
Mikulas Patocka82b15192008-10-10 13:37:09 +0100329 BUG_ON(d->dm_dev.bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330
Tejun Heod4d77622010-11-13 11:55:18 +0100331 bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 if (IS_ERR(bdev))
333 return PTR_ERR(bdev);
Tejun Heoe09b4572010-11-13 11:55:17 +0100334
Tejun Heoe09b4572010-11-13 11:55:17 +0100335 r = bd_link_disk_holder(bdev, dm_disk(md));
336 if (r) {
Tejun Heoe525fd82010-11-13 11:55:17 +0100337 blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
Tejun Heoe09b4572010-11-13 11:55:17 +0100338 return r;
339 }
340
341 d->dm_dev.bdev = bdev;
342 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343}
344
345/*
346 * Close a device that we've been using.
347 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100348static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349{
Mikulas Patocka82b15192008-10-10 13:37:09 +0100350 if (!d->dm_dev.bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 return;
352
Tejun Heo49731ba2011-01-14 18:43:57 +0100353 bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
Tejun Heoe525fd82010-11-13 11:55:17 +0100354 blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
Mikulas Patocka82b15192008-10-10 13:37:09 +0100355 d->dm_dev.bdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356}
357
358/*
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100359 * If possible, this checks an area of a destination device is invalid.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 */
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100361static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
362 sector_t start, sector_t len, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363{
Milan Brozf4808ca2011-05-29 13:02:52 +0100364 struct request_queue *q;
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100365 struct queue_limits *limits = data;
366 struct block_device *bdev = dev->bdev;
367 sector_t dev_size =
368 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100369 unsigned short logical_block_size_sectors =
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100370 limits->logical_block_size >> SECTOR_SHIFT;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100371 char b[BDEVNAME_SIZE];
Mike Anderson2cd54d92007-05-09 02:32:57 -0700372
Milan Brozf4808ca2011-05-29 13:02:52 +0100373 /*
374 * Some devices exist without request functions,
375 * such as loop devices not yet bound to backing files.
376 * Forbid the use of such devices.
377 */
378 q = bdev_get_queue(bdev);
379 if (!q || !q->make_request_fn) {
380 DMWARN("%s: %s is not yet initialised: "
381 "start=%llu, len=%llu, dev_size=%llu",
382 dm_device_name(ti->table->md), bdevname(bdev, b),
383 (unsigned long long)start,
384 (unsigned long long)len,
385 (unsigned long long)dev_size);
386 return 1;
387 }
388
Mike Anderson2cd54d92007-05-09 02:32:57 -0700389 if (!dev_size)
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100390 return 0;
Mike Anderson2cd54d92007-05-09 02:32:57 -0700391
Mike Snitzer5dea2712009-07-23 20:30:42 +0100392 if ((start >= dev_size) || (start + len > dev_size)) {
Mike Snitzera963a952009-09-04 20:40:24 +0100393 DMWARN("%s: %s too small for target: "
394 "start=%llu, len=%llu, dev_size=%llu",
395 dm_device_name(ti->table->md), bdevname(bdev, b),
396 (unsigned long long)start,
397 (unsigned long long)len,
398 (unsigned long long)dev_size);
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100399 return 1;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100400 }
401
402 if (logical_block_size_sectors <= 1)
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100403 return 0;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100404
405 if (start & (logical_block_size_sectors - 1)) {
406 DMWARN("%s: start=%llu not aligned to h/w "
Mike Snitzera963a952009-09-04 20:40:24 +0100407 "logical block size %u of %s",
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100408 dm_device_name(ti->table->md),
409 (unsigned long long)start,
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100410 limits->logical_block_size, bdevname(bdev, b));
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100411 return 1;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100412 }
413
Mike Snitzer5dea2712009-07-23 20:30:42 +0100414 if (len & (logical_block_size_sectors - 1)) {
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100415 DMWARN("%s: len=%llu not aligned to h/w "
Mike Snitzera963a952009-09-04 20:40:24 +0100416 "logical block size %u of %s",
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100417 dm_device_name(ti->table->md),
Mike Snitzer5dea2712009-07-23 20:30:42 +0100418 (unsigned long long)len,
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100419 limits->logical_block_size, bdevname(bdev, b));
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100420 return 1;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100421 }
422
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100423 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424}
425
426/*
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100427 * This upgrades the mode on an already open dm_dev, being
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 * careful to leave things as they were if we fail to reopen the
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100429 * device and not to touch the existing bdev field in case
430 * it is accessed concurrently inside dm_table_any_congested().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 */
Al Viroaeb5d722008-09-02 15:28:45 -0400432static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
Mikulas Patocka82b15192008-10-10 13:37:09 +0100433 struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434{
435 int r;
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100436 struct dm_dev_internal dd_new, dd_old;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100438 dd_new = dd_old = *dd;
439
440 dd_new.dm_dev.mode |= new_mode;
441 dd_new.dm_dev.bdev = NULL;
442
443 r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
444 if (r)
445 return r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446
Mikulas Patocka82b15192008-10-10 13:37:09 +0100447 dd->dm_dev.mode |= new_mode;
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100448 close_dev(&dd_old, md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100450 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451}
452
453/*
454 * Add a device to the list, or just increment the usage count if
455 * it's already present.
456 */
Mike Snitzer08649012011-08-02 12:32:04 +0100457int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
458 struct dm_dev **result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459{
460 int r;
Andrew Morton69a2ce72008-02-08 02:10:14 +0000461 dev_t uninitialized_var(dev);
Mikulas Patocka82b15192008-10-10 13:37:09 +0100462 struct dm_dev_internal *dd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 unsigned int major, minor;
Mike Snitzer08649012011-08-02 12:32:04 +0100464 struct dm_table *t = ti->table;
Mikulas Patocka31998ef2012-03-28 18:41:26 +0100465 char dummy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466
Eric Sesterhenn547bc922006-03-26 18:22:50 +0200467 BUG_ON(!t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468
Mikulas Patocka31998ef2012-03-28 18:41:26 +0100469 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 /* Extract the major/minor numbers */
471 dev = MKDEV(major, minor);
472 if (MAJOR(dev) != major || MINOR(dev) != minor)
473 return -EOVERFLOW;
474 } else {
475 /* convert the path to a device */
Christoph Hellwig72e82642008-08-11 00:24:08 +0200476 struct block_device *bdev = lookup_bdev(path);
477
478 if (IS_ERR(bdev))
479 return PTR_ERR(bdev);
480 dev = bdev->bd_dev;
481 bdput(bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 }
483
484 dd = find_device(&t->devices, dev);
485 if (!dd) {
486 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
487 if (!dd)
488 return -ENOMEM;
489
Mikulas Patocka82b15192008-10-10 13:37:09 +0100490 dd->dm_dev.mode = mode;
491 dd->dm_dev.bdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800493 if ((r = open_dev(dd, dev, t->md))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 kfree(dd);
495 return r;
496 }
497
Mikulas Patocka82b15192008-10-10 13:37:09 +0100498 format_dev_t(dd->dm_dev.name, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499
500 atomic_set(&dd->count, 0);
501 list_add(&dd->list, &t->devices);
502
Mikulas Patocka82b15192008-10-10 13:37:09 +0100503 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800504 r = upgrade_mode(dd, mode, t->md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 if (r)
506 return r;
507 }
508 atomic_inc(&dd->count);
509
Mikulas Patocka82b15192008-10-10 13:37:09 +0100510 *result = &dd->dm_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 return 0;
512}
Mike Snitzer08649012011-08-02 12:32:04 +0100513EXPORT_SYMBOL(dm_get_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100515int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
Mike Snitzer5dea2712009-07-23 20:30:42 +0100516 sector_t start, sector_t len, void *data)
Bryn Reeves3cb40212006-10-03 01:15:42 -0700517{
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100518 struct queue_limits *limits = data;
519 struct block_device *bdev = dev->bdev;
Jens Axboe165125e2007-07-24 09:28:11 +0200520 struct request_queue *q = bdev_get_queue(bdev);
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +0100521 char b[BDEVNAME_SIZE];
522
523 if (unlikely(!q)) {
524 DMWARN("%s: Cannot set limits for nonexistent device %s",
525 dm_device_name(ti->table->md), bdevname(bdev, b));
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100526 return 0;
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +0100527 }
Bryn Reeves3cb40212006-10-03 01:15:42 -0700528
Martin K. Petersenb27d7f12010-01-11 03:21:50 -0500529 if (bdev_stack_limits(limits, bdev, start) < 0)
530 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
Mike Snitzera963a952009-09-04 20:40:24 +0100531 "physical_block_size=%u, logical_block_size=%u, "
532 "alignment_offset=%u, start=%llu",
533 dm_device_name(ti->table->md), bdevname(bdev, b),
534 q->limits.physical_block_size,
535 q->limits.logical_block_size,
536 q->limits.alignment_offset,
Martin K. Petersenb27d7f12010-01-11 03:21:50 -0500537 (unsigned long long) start << SECTOR_SHIFT);
Bryn Reeves3cb40212006-10-03 01:15:42 -0700538
Milan Broz9980c632008-07-21 12:00:39 +0100539 /*
540 * Check if merge fn is supported.
541 * If not we'll force DM to use PAGE_SIZE or
542 * smaller I/O, just to be safe.
Bryn Reeves3cb40212006-10-03 01:15:42 -0700543 */
Mikulas Patockad5b9dd02011-08-02 12:32:04 +0100544 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
Mike Snitzer72d4cd92010-12-17 08:34:20 +0100545 blk_limits_max_hw_sectors(limits,
546 (unsigned int) (PAGE_SIZE >> 9));
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100547 return 0;
Bryn Reeves3cb40212006-10-03 01:15:42 -0700548}
549EXPORT_SYMBOL_GPL(dm_set_device_limits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551/*
Mike Snitzer08649012011-08-02 12:32:04 +0100552 * Decrement a device's use count and remove it if necessary.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100554void dm_put_device(struct dm_target *ti, struct dm_dev *d)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555{
Mikulas Patocka82b15192008-10-10 13:37:09 +0100556 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
557 dm_dev);
558
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 if (atomic_dec_and_test(&dd->count)) {
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800560 close_dev(dd, ti->table->md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 list_del(&dd->list);
562 kfree(dd);
563 }
564}
Mike Snitzer08649012011-08-02 12:32:04 +0100565EXPORT_SYMBOL(dm_put_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566
567/*
568 * Checks to see if the target joins onto the end of the table.
569 */
570static int adjoin(struct dm_table *table, struct dm_target *ti)
571{
572 struct dm_target *prev;
573
574 if (!table->num_targets)
575 return !ti->begin;
576
577 prev = &table->targets[table->num_targets - 1];
578 return (ti->begin == (prev->begin + prev->len));
579}
580
581/*
582 * Used to dynamically allocate the arg array.
583 */
584static char **realloc_argv(unsigned *array_size, char **old_argv)
585{
586 char **argv;
587 unsigned new_size;
588
589 new_size = *array_size ? *array_size * 2 : 64;
590 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
591 if (argv) {
592 memcpy(argv, old_argv, *array_size * sizeof(*argv));
593 *array_size = new_size;
594 }
595
596 kfree(old_argv);
597 return argv;
598}
599
600/*
601 * Destructively splits up the argument list to pass to ctr.
602 */
603int dm_split_args(int *argc, char ***argvp, char *input)
604{
605 char *start, *end = input, *out, **argv = NULL;
606 unsigned array_size = 0;
607
608 *argc = 0;
David Teigland814d6862006-06-26 00:27:31 -0700609
610 if (!input) {
611 *argvp = NULL;
612 return 0;
613 }
614
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 argv = realloc_argv(&array_size, argv);
616 if (!argv)
617 return -ENOMEM;
618
619 while (1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 /* Skip whitespace */
André Goddard Rosae7d28602009-12-14 18:01:06 -0800621 start = skip_spaces(end);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622
623 if (!*start)
624 break; /* success, we hit the end */
625
626 /* 'out' is used to remove any back-quotes */
627 end = out = start;
628 while (*end) {
629 /* Everything apart from '\0' can be quoted */
630 if (*end == '\\' && *(end + 1)) {
631 *out++ = *(end + 1);
632 end += 2;
633 continue;
634 }
635
636 if (isspace(*end))
637 break; /* end of token */
638
639 *out++ = *end++;
640 }
641
642 /* have we already filled the array ? */
643 if ((*argc + 1) > array_size) {
644 argv = realloc_argv(&array_size, argv);
645 if (!argv)
646 return -ENOMEM;
647 }
648
649 /* we know this is whitespace */
650 if (*end)
651 end++;
652
653 /* terminate the string and put it in the array */
654 *out = '\0';
655 argv[*argc] = start;
656 (*argc)++;
657 }
658
659 *argvp = argv;
660 return 0;
661}
662
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100663/*
664 * Impose necessary and sufficient conditions on a devices's table such
665 * that any incoming bio which respects its logical_block_size can be
666 * processed successfully. If it falls across the boundary between
667 * two or more targets, the size of each piece it gets split into must
668 * be compatible with the logical_block_size of the target processing it.
669 */
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100670static int validate_hardware_logical_block_alignment(struct dm_table *table,
671 struct queue_limits *limits)
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100672{
673 /*
674 * This function uses arithmetic modulo the logical_block_size
675 * (in units of 512-byte sectors).
676 */
677 unsigned short device_logical_block_size_sects =
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100678 limits->logical_block_size >> SECTOR_SHIFT;
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100679
680 /*
681 * Offset of the start of the next table entry, mod logical_block_size.
682 */
683 unsigned short next_target_start = 0;
684
685 /*
686 * Given an aligned bio that extends beyond the end of a
687 * target, how many sectors must the next target handle?
688 */
689 unsigned short remaining = 0;
690
691 struct dm_target *uninitialized_var(ti);
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100692 struct queue_limits ti_limits;
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100693 unsigned i = 0;
694
695 /*
696 * Check each entry in the table in turn.
697 */
698 while (i < dm_table_get_num_targets(table)) {
699 ti = dm_table_get_target(table, i++);
700
Martin K. Petersenb1bd0552012-01-11 16:27:11 +0100701 blk_set_stacking_limits(&ti_limits);
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100702
703 /* combine all target devices' limits */
704 if (ti->type->iterate_devices)
705 ti->type->iterate_devices(ti, dm_set_device_limits,
706 &ti_limits);
707
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100708 /*
709 * If the remaining sectors fall entirely within this
710 * table entry are they compatible with its logical_block_size?
711 */
712 if (remaining < ti->len &&
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100713 remaining & ((ti_limits.logical_block_size >>
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100714 SECTOR_SHIFT) - 1))
715 break; /* Error */
716
717 next_target_start =
718 (unsigned short) ((next_target_start + ti->len) &
719 (device_logical_block_size_sects - 1));
720 remaining = next_target_start ?
721 device_logical_block_size_sects - next_target_start : 0;
722 }
723
724 if (remaining) {
725 DMWARN("%s: table line %u (start sect %llu len %llu) "
Mike Snitzera963a952009-09-04 20:40:24 +0100726 "not aligned to h/w logical block size %u",
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100727 dm_device_name(table->md), i,
728 (unsigned long long) ti->begin,
729 (unsigned long long) ti->len,
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100730 limits->logical_block_size);
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100731 return -EINVAL;
732 }
733
734 return 0;
735}
736
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737int dm_table_add_target(struct dm_table *t, const char *type,
738 sector_t start, sector_t len, char *params)
739{
740 int r = -EINVAL, argc;
741 char **argv;
742 struct dm_target *tgt;
743
Alasdair G Kergon3791e2f2011-10-31 20:19:00 +0000744 if (t->singleton) {
745 DMERR("%s: target type %s must appear alone in table",
746 dm_device_name(t->md), t->targets->type->name);
747 return -EINVAL;
748 }
749
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 if ((r = check_space(t)))
751 return r;
752
753 tgt = t->targets + t->num_targets;
754 memset(tgt, 0, sizeof(*tgt));
755
756 if (!len) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700757 DMERR("%s: zero-length target", dm_device_name(t->md));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 return -EINVAL;
759 }
760
761 tgt->type = dm_get_target_type(type);
762 if (!tgt->type) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700763 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
764 type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 return -EINVAL;
766 }
767
Alasdair G Kergon3791e2f2011-10-31 20:19:00 +0000768 if (dm_target_needs_singleton(tgt->type)) {
769 if (t->num_targets) {
770 DMERR("%s: target type %s must appear alone in table",
771 dm_device_name(t->md), type);
772 return -EINVAL;
773 }
774 t->singleton = 1;
775 }
776
Alasdair G Kergoncc6cbe12011-10-31 20:19:02 +0000777 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
778 DMERR("%s: target type %s may not be included in read-only tables",
779 dm_device_name(t->md), type);
780 return -EINVAL;
781 }
782
Alasdair G Kergon36a04562011-10-31 20:19:04 +0000783 if (t->immutable_target_type) {
784 if (t->immutable_target_type != tgt->type) {
785 DMERR("%s: immutable target type %s cannot be mixed with other target types",
786 dm_device_name(t->md), t->immutable_target_type->name);
787 return -EINVAL;
788 }
789 } else if (dm_target_is_immutable(tgt->type)) {
790 if (t->num_targets) {
791 DMERR("%s: immutable target type %s cannot be mixed with other target types",
792 dm_device_name(t->md), tgt->type->name);
793 return -EINVAL;
794 }
795 t->immutable_target_type = tgt->type;
796 }
797
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 tgt->table = t;
799 tgt->begin = start;
800 tgt->len = len;
801 tgt->error = "Unknown error";
802
803 /*
804 * Does this target adjoin the previous one ?
805 */
806 if (!adjoin(t, tgt)) {
807 tgt->error = "Gap in table";
808 r = -EINVAL;
809 goto bad;
810 }
811
812 r = dm_split_args(&argc, &argv, params);
813 if (r) {
814 tgt->error = "couldn't split parameters (insufficient memory)";
815 goto bad;
816 }
817
818 r = tgt->type->ctr(tgt, argc, argv);
819 kfree(argv);
820 if (r)
821 goto bad;
822
823 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
824
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +0000825 if (!tgt->num_discard_bios && tgt->discards_supported)
826 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
Mike Snitzer936688d2011-08-02 12:32:01 +0100827 dm_device_name(t->md), type);
Mike Snitzer5ae89a82010-08-12 04:14:08 +0100828
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 return 0;
830
831 bad:
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700832 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 dm_put_target_type(tgt->type);
834 return r;
835}
836
Mike Snitzer498f0102011-08-02 12:32:04 +0100837/*
838 * Target argument parsing helpers.
839 */
840static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
841 unsigned *value, char **error, unsigned grouped)
842{
843 const char *arg_str = dm_shift_arg(arg_set);
Mikulas Patocka31998ef2012-03-28 18:41:26 +0100844 char dummy;
Mike Snitzer498f0102011-08-02 12:32:04 +0100845
846 if (!arg_str ||
Mikulas Patocka31998ef2012-03-28 18:41:26 +0100847 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
Mike Snitzer498f0102011-08-02 12:32:04 +0100848 (*value < arg->min) ||
849 (*value > arg->max) ||
850 (grouped && arg_set->argc < *value)) {
851 *error = arg->error;
852 return -EINVAL;
853 }
854
855 return 0;
856}
857
858int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
859 unsigned *value, char **error)
860{
861 return validate_next_arg(arg, arg_set, value, error, 0);
862}
863EXPORT_SYMBOL(dm_read_arg);
864
865int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
866 unsigned *value, char **error)
867{
868 return validate_next_arg(arg, arg_set, value, error, 1);
869}
870EXPORT_SYMBOL(dm_read_arg_group);
871
872const char *dm_shift_arg(struct dm_arg_set *as)
873{
874 char *r;
875
876 if (as->argc) {
877 as->argc--;
878 r = *as->argv;
879 as->argv++;
880 return r;
881 }
882
883 return NULL;
884}
885EXPORT_SYMBOL(dm_shift_arg);
886
887void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
888{
889 BUG_ON(as->argc < num_args);
890 as->argc -= num_args;
891 as->argv += num_args;
892}
893EXPORT_SYMBOL(dm_consume_args);
894
Will Drewry26803b92010-08-12 04:14:03 +0100895static int dm_table_set_type(struct dm_table *t)
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100896{
897 unsigned i;
898 unsigned bio_based = 0, request_based = 0;
899 struct dm_target *tgt;
900 struct dm_dev_internal *dd;
901 struct list_head *devices;
902
903 for (i = 0; i < t->num_targets; i++) {
904 tgt = t->targets + i;
905 if (dm_target_request_based(tgt))
906 request_based = 1;
907 else
908 bio_based = 1;
909
910 if (bio_based && request_based) {
911 DMWARN("Inconsistent table: different target types"
912 " can't be mixed up");
913 return -EINVAL;
914 }
915 }
916
917 if (bio_based) {
918 /* We must use this table as bio-based */
919 t->type = DM_TYPE_BIO_BASED;
920 return 0;
921 }
922
923 BUG_ON(!request_based); /* No targets in this table */
924
925 /* Non-request-stackable devices can't be used for request-based dm */
926 devices = dm_table_get_devices(t);
927 list_for_each_entry(dd, devices, list) {
928 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
929 DMWARN("table load rejected: including"
930 " non-request-stackable devices");
931 return -EINVAL;
932 }
933 }
934
935 /*
936 * Request-based dm supports only tables that have a single target now.
937 * To support multiple targets, request splitting support is needed,
938 * and that needs lots of changes in the block-layer.
939 * (e.g. request completion process for partial completion.)
940 */
941 if (t->num_targets > 1) {
942 DMWARN("Request-based dm doesn't support multiple targets yet");
943 return -EINVAL;
944 }
945
946 t->type = DM_TYPE_REQUEST_BASED;
947
948 return 0;
949}
950
951unsigned dm_table_get_type(struct dm_table *t)
952{
953 return t->type;
954}
955
Alasdair G Kergon36a04562011-10-31 20:19:04 +0000956struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
957{
958 return t->immutable_target_type;
959}
960
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100961bool dm_table_request_based(struct dm_table *t)
962{
963 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
964}
965
966int dm_table_alloc_md_mempools(struct dm_table *t)
967{
968 unsigned type = dm_table_get_type(t);
Mikulas Patockac0820cf2012-12-21 20:23:38 +0000969 unsigned per_bio_data_size = 0;
970 struct dm_target *tgt;
971 unsigned i;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100972
973 if (unlikely(type == DM_TYPE_NONE)) {
974 DMWARN("no table type is set, can't allocate mempools");
975 return -EINVAL;
976 }
977
Mikulas Patockac0820cf2012-12-21 20:23:38 +0000978 if (type == DM_TYPE_BIO_BASED)
979 for (i = 0; i < t->num_targets; i++) {
980 tgt = t->targets + i;
981 per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
982 }
983
984 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported, per_bio_data_size);
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100985 if (!t->mempools)
986 return -ENOMEM;
987
988 return 0;
989}
990
991void dm_table_free_md_mempools(struct dm_table *t)
992{
993 dm_free_md_mempools(t->mempools);
994 t->mempools = NULL;
995}
996
997struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
998{
999 return t->mempools;
1000}
1001
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002static int setup_indexes(struct dm_table *t)
1003{
1004 int i;
1005 unsigned int total = 0;
1006 sector_t *indexes;
1007
1008 /* allocate the space for *all* the indexes */
1009 for (i = t->depth - 2; i >= 0; i--) {
1010 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1011 total += t->counts[i];
1012 }
1013
1014 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1015 if (!indexes)
1016 return -ENOMEM;
1017
1018 /* set up internal nodes, bottom-up */
Jun'ichi Nomura82d601d2008-02-08 02:10:04 +00001019 for (i = t->depth - 2; i >= 0; i--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 t->index[i] = indexes;
1021 indexes += (KEYS_PER_NODE * t->counts[i]);
1022 setup_btree_index(i, t);
1023 }
1024
1025 return 0;
1026}
1027
1028/*
1029 * Builds the btree to index the map.
1030 */
Will Drewry26803b92010-08-12 04:14:03 +01001031static int dm_table_build_index(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032{
1033 int r = 0;
1034 unsigned int leaf_nodes;
1035
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 /* how many indexes will the btree have ? */
1037 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1038 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1039
1040 /* leaf layer has already been set up */
1041 t->counts[t->depth - 1] = leaf_nodes;
1042 t->index[t->depth - 1] = t->highs;
1043
1044 if (t->depth >= 2)
1045 r = setup_indexes(t);
1046
1047 return r;
1048}
1049
Will Drewry26803b92010-08-12 04:14:03 +01001050/*
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001051 * Get a disk whose integrity profile reflects the table's profile.
1052 * If %match_all is true, all devices' profiles must match.
1053 * If %match_all is false, all devices must at least have an
1054 * allocated integrity profile; but uninitialized is ok.
1055 * Returns NULL if integrity support was inconsistent or unavailable.
1056 */
1057static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1058 bool match_all)
1059{
1060 struct list_head *devices = dm_table_get_devices(t);
1061 struct dm_dev_internal *dd = NULL;
1062 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1063
1064 list_for_each_entry(dd, devices, list) {
1065 template_disk = dd->dm_dev.bdev->bd_disk;
1066 if (!blk_get_integrity(template_disk))
1067 goto no_integrity;
1068 if (!match_all && !blk_integrity_is_initialized(template_disk))
1069 continue; /* skip uninitialized profiles */
1070 else if (prev_disk &&
1071 blk_integrity_compare(prev_disk, template_disk) < 0)
1072 goto no_integrity;
1073 prev_disk = template_disk;
1074 }
1075
1076 return template_disk;
1077
1078no_integrity:
1079 if (prev_disk)
1080 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1081 dm_device_name(t->md),
1082 prev_disk->disk_name,
1083 template_disk->disk_name);
1084 return NULL;
1085}
1086
1087/*
Will Drewry26803b92010-08-12 04:14:03 +01001088 * Register the mapped device for blk_integrity support if
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001089 * the underlying devices have an integrity profile. But all devices
1090 * may not have matching profiles (checking all devices isn't reliable
1091 * during table load because this table may use other DM device(s) which
1092 * must be resumed before they will have an initialized integity profile).
1093 * Stacked DM devices force a 2 stage integrity profile validation:
1094 * 1 - during load, validate all initialized integrity profiles match
1095 * 2 - during resume, validate all integrity profiles match
Will Drewry26803b92010-08-12 04:14:03 +01001096 */
1097static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1098{
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001099 struct gendisk *template_disk = NULL;
Will Drewry26803b92010-08-12 04:14:03 +01001100
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001101 template_disk = dm_table_get_integrity_disk(t, false);
1102 if (!template_disk)
1103 return 0;
Will Drewry26803b92010-08-12 04:14:03 +01001104
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001105 if (!blk_integrity_is_initialized(dm_disk(md))) {
1106 t->integrity_supported = 1;
1107 return blk_integrity_register(dm_disk(md), NULL);
1108 }
1109
1110 /*
1111 * If DM device already has an initalized integrity
1112 * profile the new profile should not conflict.
1113 */
1114 if (blk_integrity_is_initialized(template_disk) &&
1115 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1116 DMWARN("%s: conflict with existing integrity profile: "
1117 "%s profile mismatch",
1118 dm_device_name(t->md),
1119 template_disk->disk_name);
1120 return 1;
1121 }
1122
1123 /* Preserve existing initialized integrity profile */
1124 t->integrity_supported = 1;
Will Drewry26803b92010-08-12 04:14:03 +01001125 return 0;
1126}
1127
1128/*
1129 * Prepares the table for use by building the indices,
1130 * setting the type, and allocating mempools.
1131 */
1132int dm_table_complete(struct dm_table *t)
1133{
1134 int r;
1135
1136 r = dm_table_set_type(t);
1137 if (r) {
1138 DMERR("unable to set table type");
1139 return r;
1140 }
1141
1142 r = dm_table_build_index(t);
1143 if (r) {
1144 DMERR("unable to build btrees");
1145 return r;
1146 }
1147
1148 r = dm_table_prealloc_integrity(t, t->md);
1149 if (r) {
1150 DMERR("could not register integrity profile.");
1151 return r;
1152 }
1153
1154 r = dm_table_alloc_md_mempools(t);
1155 if (r)
1156 DMERR("unable to allocate mempools");
1157
1158 return r;
1159}
1160
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001161static DEFINE_MUTEX(_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162void dm_table_event_callback(struct dm_table *t,
1163 void (*fn)(void *), void *context)
1164{
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001165 mutex_lock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 t->event_fn = fn;
1167 t->event_context = context;
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001168 mutex_unlock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169}
1170
1171void dm_table_event(struct dm_table *t)
1172{
1173 /*
1174 * You can no longer call dm_table_event() from interrupt
1175 * context, use a bottom half instead.
1176 */
1177 BUG_ON(in_interrupt());
1178
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001179 mutex_lock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180 if (t->event_fn)
1181 t->event_fn(t->event_context);
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001182 mutex_unlock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183}
Mike Snitzer08649012011-08-02 12:32:04 +01001184EXPORT_SYMBOL(dm_table_event);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185
1186sector_t dm_table_get_size(struct dm_table *t)
1187{
1188 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1189}
Mike Snitzer08649012011-08-02 12:32:04 +01001190EXPORT_SYMBOL(dm_table_get_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191
1192struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1193{
Milan Broz14353532006-06-26 00:27:27 -07001194 if (index >= t->num_targets)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 return NULL;
1196
1197 return t->targets + index;
1198}
1199
1200/*
1201 * Search the btree for the correct target.
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001202 *
1203 * Caller should check returned pointer with dm_target_is_valid()
1204 * to trap I/O beyond end of device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 */
1206struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1207{
1208 unsigned int l, n = 0, k = 0;
1209 sector_t *node;
1210
1211 for (l = 0; l < t->depth; l++) {
1212 n = get_child(n, k);
1213 node = get_node(t, l, n);
1214
1215 for (k = 0; k < KEYS_PER_NODE; k++)
1216 if (node[k] >= sector)
1217 break;
1218 }
1219
1220 return &t->targets[(KEYS_PER_NODE * n) + k];
1221}
1222
Mike Snitzer3ae70652012-09-26 23:45:45 +01001223static int count_device(struct dm_target *ti, struct dm_dev *dev,
1224 sector_t start, sector_t len, void *data)
1225{
1226 unsigned *num_devices = data;
1227
1228 (*num_devices)++;
1229
1230 return 0;
1231}
1232
1233/*
1234 * Check whether a table has no data devices attached using each
1235 * target's iterate_devices method.
1236 * Returns false if the result is unknown because a target doesn't
1237 * support iterate_devices.
1238 */
1239bool dm_table_has_no_data_devices(struct dm_table *table)
1240{
1241 struct dm_target *uninitialized_var(ti);
1242 unsigned i = 0, num_devices = 0;
1243
1244 while (i < dm_table_get_num_targets(table)) {
1245 ti = dm_table_get_target(table, i++);
1246
1247 if (!ti->type->iterate_devices)
1248 return false;
1249
1250 ti->type->iterate_devices(ti, count_device, &num_devices);
1251 if (num_devices)
1252 return false;
1253 }
1254
1255 return true;
1256}
1257
Martin K. Petersen9c470082009-04-09 00:27:12 +01001258/*
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001259 * Establish the new table's queue_limits and validate them.
1260 */
1261int dm_calculate_queue_limits(struct dm_table *table,
1262 struct queue_limits *limits)
1263{
1264 struct dm_target *uninitialized_var(ti);
1265 struct queue_limits ti_limits;
1266 unsigned i = 0;
1267
Martin K. Petersenb1bd0552012-01-11 16:27:11 +01001268 blk_set_stacking_limits(limits);
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001269
1270 while (i < dm_table_get_num_targets(table)) {
Martin K. Petersenb1bd0552012-01-11 16:27:11 +01001271 blk_set_stacking_limits(&ti_limits);
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001272
1273 ti = dm_table_get_target(table, i++);
1274
1275 if (!ti->type->iterate_devices)
1276 goto combine_limits;
1277
1278 /*
1279 * Combine queue limits of all the devices this target uses.
1280 */
1281 ti->type->iterate_devices(ti, dm_set_device_limits,
1282 &ti_limits);
1283
Mike Snitzer40bea432009-09-04 20:40:25 +01001284 /* Set I/O hints portion of queue limits */
1285 if (ti->type->io_hints)
1286 ti->type->io_hints(ti, &ti_limits);
1287
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001288 /*
1289 * Check each device area is consistent with the target's
1290 * overall queue limits.
1291 */
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +01001292 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1293 &ti_limits))
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001294 return -EINVAL;
1295
1296combine_limits:
1297 /*
1298 * Merge this target's queue limits into the overall limits
1299 * for the table.
1300 */
1301 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
Martin K. Petersenb27d7f12010-01-11 03:21:50 -05001302 DMWARN("%s: adding target device "
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001303 "(start sect %llu len %llu) "
Martin K. Petersenb27d7f12010-01-11 03:21:50 -05001304 "caused an alignment inconsistency",
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001305 dm_device_name(table->md),
1306 (unsigned long long) ti->begin,
1307 (unsigned long long) ti->len);
1308 }
1309
1310 return validate_hardware_logical_block_alignment(table, limits);
1311}
1312
1313/*
Martin K. Petersen9c470082009-04-09 00:27:12 +01001314 * Set the integrity profile for this device if all devices used have
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001315 * matching profiles. We're quite deep in the resume path but still
1316 * don't know if all devices (particularly DM devices this device
1317 * may be stacked on) have matching profiles. Even if the profiles
1318 * don't match we have no way to fail (to resume) at this point.
Martin K. Petersen9c470082009-04-09 00:27:12 +01001319 */
1320static void dm_table_set_integrity(struct dm_table *t)
1321{
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001322 struct gendisk *template_disk = NULL;
Martin K. Petersen9c470082009-04-09 00:27:12 +01001323
1324 if (!blk_get_integrity(dm_disk(t->md)))
1325 return;
1326
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001327 template_disk = dm_table_get_integrity_disk(t, true);
Mike Snitzer876fbba2011-09-25 23:26:17 +01001328 if (template_disk)
1329 blk_integrity_register(dm_disk(t->md),
1330 blk_get_integrity(template_disk));
1331 else if (blk_integrity_is_initialized(dm_disk(t->md)))
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001332 DMWARN("%s: device no longer has a valid integrity profile",
1333 dm_device_name(t->md));
Mike Snitzer876fbba2011-09-25 23:26:17 +01001334 else
1335 DMWARN("%s: unable to establish an integrity profile",
1336 dm_device_name(t->md));
Martin K. Petersen9c470082009-04-09 00:27:12 +01001337}
1338
Mike Snitzered8b7522011-08-02 12:32:08 +01001339static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1340 sector_t start, sector_t len, void *data)
1341{
1342 unsigned flush = (*(unsigned *)data);
1343 struct request_queue *q = bdev_get_queue(dev->bdev);
1344
1345 return q && (q->flush_flags & flush);
1346}
1347
1348static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1349{
1350 struct dm_target *ti;
1351 unsigned i = 0;
1352
1353 /*
1354 * Require at least one underlying device to support flushes.
1355 * t->devices includes internal dm devices such as mirror logs
1356 * so we need to use iterate_devices here, which targets
1357 * supporting flushes must provide.
1358 */
1359 while (i < dm_table_get_num_targets(t)) {
1360 ti = dm_table_get_target(t, i++);
1361
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00001362 if (!ti->num_flush_bios)
Mike Snitzered8b7522011-08-02 12:32:08 +01001363 continue;
1364
Joe Thornber0e9c24e2012-07-27 15:08:07 +01001365 if (ti->flush_supported)
1366 return 1;
1367
Mike Snitzered8b7522011-08-02 12:32:08 +01001368 if (ti->type->iterate_devices &&
1369 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1370 return 1;
1371 }
1372
1373 return 0;
1374}
1375
Milan Broz983c7db2011-09-25 23:26:21 +01001376static bool dm_table_discard_zeroes_data(struct dm_table *t)
1377{
1378 struct dm_target *ti;
1379 unsigned i = 0;
1380
1381 /* Ensure that all targets supports discard_zeroes_data. */
1382 while (i < dm_table_get_num_targets(t)) {
1383 ti = dm_table_get_target(t, i++);
1384
1385 if (ti->discard_zeroes_data_unsupported)
1386 return 0;
1387 }
1388
1389 return 1;
1390}
1391
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001392static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1393 sector_t start, sector_t len, void *data)
1394{
1395 struct request_queue *q = bdev_get_queue(dev->bdev);
1396
1397 return q && blk_queue_nonrot(q);
1398}
1399
Milan Brozc3c4555e2012-09-26 23:45:43 +01001400static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1401 sector_t start, sector_t len, void *data)
1402{
1403 struct request_queue *q = bdev_get_queue(dev->bdev);
1404
1405 return q && !blk_queue_add_random(q);
1406}
1407
1408static bool dm_table_all_devices_attribute(struct dm_table *t,
1409 iterate_devices_callout_fn func)
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001410{
1411 struct dm_target *ti;
1412 unsigned i = 0;
1413
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001414 while (i < dm_table_get_num_targets(t)) {
1415 ti = dm_table_get_target(t, i++);
1416
1417 if (!ti->type->iterate_devices ||
Milan Brozc3c4555e2012-09-26 23:45:43 +01001418 !ti->type->iterate_devices(ti, func, NULL))
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001419 return 0;
1420 }
1421
1422 return 1;
1423}
1424
Mike Snitzerd54eaa52012-12-21 20:23:36 +00001425static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1426 sector_t start, sector_t len, void *data)
1427{
1428 struct request_queue *q = bdev_get_queue(dev->bdev);
1429
1430 return q && !q->limits.max_write_same_sectors;
1431}
1432
1433static bool dm_table_supports_write_same(struct dm_table *t)
1434{
1435 struct dm_target *ti;
1436 unsigned i = 0;
1437
1438 while (i < dm_table_get_num_targets(t)) {
1439 ti = dm_table_get_target(t, i++);
1440
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00001441 if (!ti->num_write_same_bios)
Mike Snitzerd54eaa52012-12-21 20:23:36 +00001442 return false;
1443
1444 if (!ti->type->iterate_devices ||
1445 !ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1446 return false;
1447 }
1448
1449 return true;
1450}
1451
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001452void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1453 struct queue_limits *limits)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454{
Mike Snitzered8b7522011-08-02 12:32:08 +01001455 unsigned flush = 0;
1456
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 /*
Mike Snitzer11977642009-06-22 10:12:32 +01001458 * Copy table's limits to the DM device's request_queue
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459 */
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001460 q->limits = *limits;
Jens Axboec9a3f6d2008-04-29 19:12:35 +02001461
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001462 if (!dm_table_supports_discards(t))
1463 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1464 else
1465 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1466
Mike Snitzered8b7522011-08-02 12:32:08 +01001467 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1468 flush |= REQ_FLUSH;
1469 if (dm_table_supports_flush(t, REQ_FUA))
1470 flush |= REQ_FUA;
1471 }
1472 blk_queue_flush(q, flush);
1473
Milan Broz983c7db2011-09-25 23:26:21 +01001474 if (!dm_table_discard_zeroes_data(t))
1475 q->limits.discard_zeroes_data = 0;
1476
Milan Brozc3c4555e2012-09-26 23:45:43 +01001477 /* Ensure that all underlying devices are non-rotational. */
1478 if (dm_table_all_devices_attribute(t, device_is_nonrot))
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001479 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1480 else
1481 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1482
Mike Snitzerd54eaa52012-12-21 20:23:36 +00001483 if (!dm_table_supports_write_same(t))
1484 q->limits.max_write_same_sectors = 0;
Mike Snitzerc1a94672012-12-21 20:23:30 +00001485
Martin K. Petersen9c470082009-04-09 00:27:12 +01001486 dm_table_set_integrity(t);
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001487
1488 /*
Milan Brozc3c4555e2012-09-26 23:45:43 +01001489 * Determine whether or not this queue's I/O timings contribute
1490 * to the entropy pool, Only request-based targets use this.
1491 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1492 * have it set.
1493 */
1494 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1495 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1496
1497 /*
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001498 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1499 * visible to other CPUs because, once the flag is set, incoming bios
1500 * are processed by request-based dm, which refers to the queue
1501 * settings.
1502 * Until the flag set, bios are passed to bio-based dm and queued to
1503 * md->deferred where queue settings are not needed yet.
1504 * Those bios are passed to request-based dm at the resume time.
1505 */
1506 smp_mb();
1507 if (dm_table_request_based(t))
1508 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001509}
1510
1511unsigned int dm_table_get_num_targets(struct dm_table *t)
1512{
1513 return t->num_targets;
1514}
1515
1516struct list_head *dm_table_get_devices(struct dm_table *t)
1517{
1518 return &t->devices;
1519}
1520
Al Viroaeb5d722008-09-02 15:28:45 -04001521fmode_t dm_table_get_mode(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001522{
1523 return t->mode;
1524}
Mike Snitzer08649012011-08-02 12:32:04 +01001525EXPORT_SYMBOL(dm_table_get_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526
1527static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1528{
1529 int i = t->num_targets;
1530 struct dm_target *ti = t->targets;
1531
1532 while (i--) {
1533 if (postsuspend) {
1534 if (ti->type->postsuspend)
1535 ti->type->postsuspend(ti);
1536 } else if (ti->type->presuspend)
1537 ti->type->presuspend(ti);
1538
1539 ti++;
1540 }
1541}
1542
1543void dm_table_presuspend_targets(struct dm_table *t)
1544{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07001545 if (!t)
1546 return;
1547
Adrian Bunke8488d02008-04-24 22:10:51 +01001548 suspend_targets(t, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549}
1550
1551void dm_table_postsuspend_targets(struct dm_table *t)
1552{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07001553 if (!t)
1554 return;
1555
Adrian Bunke8488d02008-04-24 22:10:51 +01001556 suspend_targets(t, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001557}
1558
Milan Broz8757b772006-10-03 01:15:36 -07001559int dm_table_resume_targets(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001560{
Milan Broz8757b772006-10-03 01:15:36 -07001561 int i, r = 0;
1562
1563 for (i = 0; i < t->num_targets; i++) {
1564 struct dm_target *ti = t->targets + i;
1565
1566 if (!ti->type->preresume)
1567 continue;
1568
1569 r = ti->type->preresume(ti);
1570 if (r)
1571 return r;
1572 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001573
1574 for (i = 0; i < t->num_targets; i++) {
1575 struct dm_target *ti = t->targets + i;
1576
1577 if (ti->type->resume)
1578 ti->type->resume(ti);
1579 }
Milan Broz8757b772006-10-03 01:15:36 -07001580
1581 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582}
1583
NeilBrown9d357b02011-01-13 20:00:01 +00001584void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1585{
1586 list_add(&cb->list, &t->target_callbacks);
1587}
1588EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1589
Linus Torvalds1da177e2005-04-16 15:20:36 -07001590int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1591{
Mikulas Patocka82b15192008-10-10 13:37:09 +01001592 struct dm_dev_internal *dd;
Paul Jimenezafb24522008-02-08 02:09:59 +00001593 struct list_head *devices = dm_table_get_devices(t);
NeilBrown9d357b02011-01-13 20:00:01 +00001594 struct dm_target_callbacks *cb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595 int r = 0;
1596
Paul Jimenezafb24522008-02-08 02:09:59 +00001597 list_for_each_entry(dd, devices, list) {
Mikulas Patocka82b15192008-10-10 13:37:09 +01001598 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +01001599 char b[BDEVNAME_SIZE];
1600
1601 if (likely(q))
1602 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1603 else
1604 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1605 dm_device_name(t->md),
1606 bdevname(dd->dm_dev.bdev, b));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607 }
1608
NeilBrown9d357b02011-01-13 20:00:01 +00001609 list_for_each_entry(cb, &t->target_callbacks, list)
1610 if (cb->congested_fn)
1611 r |= cb->congested_fn(cb, bdi_bits);
1612
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613 return r;
1614}
1615
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001616int dm_table_any_busy_target(struct dm_table *t)
1617{
1618 unsigned i;
1619 struct dm_target *ti;
1620
1621 for (i = 0; i < t->num_targets; i++) {
1622 ti = t->targets + i;
1623 if (ti->type->busy && ti->type->busy(ti))
1624 return 1;
1625 }
1626
1627 return 0;
1628}
1629
Mike Anderson1134e5a2006-03-27 01:17:54 -08001630struct mapped_device *dm_table_get_md(struct dm_table *t)
1631{
Mike Anderson1134e5a2006-03-27 01:17:54 -08001632 return t->md;
1633}
Mike Snitzer08649012011-08-02 12:32:04 +01001634EXPORT_SYMBOL(dm_table_get_md);
Mike Anderson1134e5a2006-03-27 01:17:54 -08001635
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001636static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1637 sector_t start, sector_t len, void *data)
1638{
1639 struct request_queue *q = bdev_get_queue(dev->bdev);
1640
1641 return q && blk_queue_discard(q);
1642}
1643
1644bool dm_table_supports_discards(struct dm_table *t)
1645{
1646 struct dm_target *ti;
1647 unsigned i = 0;
1648
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001649 /*
Mike Snitzer4c259322011-05-29 12:52:55 +01001650 * Unless any target used by the table set discards_supported,
1651 * require at least one underlying device to support discards.
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001652 * t->devices includes internal dm devices such as mirror logs
1653 * so we need to use iterate_devices here, which targets
Mike Snitzer936688d2011-08-02 12:32:01 +01001654 * supporting discard selectively must provide.
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001655 */
1656 while (i < dm_table_get_num_targets(t)) {
1657 ti = dm_table_get_target(t, i++);
1658
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00001659 if (!ti->num_discard_bios)
Mike Snitzer936688d2011-08-02 12:32:01 +01001660 continue;
1661
Mike Snitzer4c259322011-05-29 12:52:55 +01001662 if (ti->discards_supported)
1663 return 1;
1664
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001665 if (ti->type->iterate_devices &&
1666 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1667 return 1;
1668 }
1669
1670 return 0;
1671}