blob: 8f8783533ac7e13383aed49eff8a40ba3a0218bf [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
29struct dm_table {
Mike Anderson1134e5a2006-03-27 01:17:54 -080030 struct mapped_device *md;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +010031 unsigned type;
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33 /* btree table */
34 unsigned int depth;
35 unsigned int counts[MAX_DEPTH]; /* in nodes */
36 sector_t *index[MAX_DEPTH];
37
38 unsigned int num_targets;
39 unsigned int num_allocated;
40 sector_t *highs;
41 struct dm_target *targets;
42
Alasdair G Kergon36a04562011-10-31 20:19:04 +000043 struct target_type *immutable_target_type;
Martin K. Petersena91a2782011-03-17 11:11:05 +010044 unsigned integrity_supported:1;
Alasdair G Kergon3791e2f2011-10-31 20:19:00 +000045 unsigned singleton:1;
Mike Snitzer5ae89a82010-08-12 04:14:08 +010046
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 /*
48 * Indicates the rw permissions for the new logical
49 * device. This should be a combination of FMODE_READ
50 * and FMODE_WRITE.
51 */
Al Viroaeb5d722008-09-02 15:28:45 -040052 fmode_t mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54 /* a list of devices used by this table */
55 struct list_head devices;
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 /* events get handed up using this callback */
58 void (*event_fn)(void *);
59 void *event_context;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +010060
61 struct dm_md_mempools *mempools;
NeilBrown9d357b02011-01-13 20:00:01 +000062
63 struct list_head target_callbacks;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064};
65
66/*
67 * Similar to ceiling(log_size(n))
68 */
69static unsigned int int_log(unsigned int n, unsigned int base)
70{
71 int result = 0;
72
73 while (n > 1) {
74 n = dm_div_up(n, base);
75 result++;
76 }
77
78 return result;
79}
80
81/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 * Calculate the index of the child node of the n'th node k'th key.
83 */
84static inline unsigned int get_child(unsigned int n, unsigned int k)
85{
86 return (n * CHILDREN_PER_NODE) + k;
87}
88
89/*
90 * Return the n'th node of level l from table t.
91 */
92static inline sector_t *get_node(struct dm_table *t,
93 unsigned int l, unsigned int n)
94{
95 return t->index[l] + (n * KEYS_PER_NODE);
96}
97
98/*
99 * Return the highest key that you could lookup from the n'th
100 * node on level l of the btree.
101 */
102static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
103{
104 for (; l < t->depth - 1; l++)
105 n = get_child(n, CHILDREN_PER_NODE - 1);
106
107 if (n >= t->counts[l])
108 return (sector_t) - 1;
109
110 return get_node(t, l, n)[KEYS_PER_NODE - 1];
111}
112
113/*
114 * Fills in a level of the btree based on the highs of the level
115 * below it.
116 */
117static int setup_btree_index(unsigned int l, struct dm_table *t)
118{
119 unsigned int n, k;
120 sector_t *node;
121
122 for (n = 0U; n < t->counts[l]; n++) {
123 node = get_node(t, l, n);
124
125 for (k = 0U; k < KEYS_PER_NODE; k++)
126 node[k] = high(t, l + 1, get_child(n, k));
127 }
128
129 return 0;
130}
131
132void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
133{
134 unsigned long size;
135 void *addr;
136
137 /*
138 * Check that we're not going to overflow.
139 */
140 if (nmemb > (ULONG_MAX / elem_size))
141 return NULL;
142
143 size = nmemb * elem_size;
Joe Perchese29e65a2011-08-02 12:32:02 +0100144 addr = vzalloc(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
146 return addr;
147}
Mike Snitzer08649012011-08-02 12:32:04 +0100148EXPORT_SYMBOL(dm_vcalloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
150/*
151 * highs, and targets are managed as dynamic arrays during a
152 * table load.
153 */
154static int alloc_targets(struct dm_table *t, unsigned int num)
155{
156 sector_t *n_highs;
157 struct dm_target *n_targets;
158 int n = t->num_targets;
159
160 /*
161 * Allocate both the target array and offset array at once.
Jun'ichi Nomura512875b2007-12-13 14:15:25 +0000162 * Append an empty entry to catch sectors beyond the end of
163 * the device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 */
Jun'ichi Nomura512875b2007-12-13 14:15:25 +0000165 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 sizeof(sector_t));
167 if (!n_highs)
168 return -ENOMEM;
169
170 n_targets = (struct dm_target *) (n_highs + num);
171
172 if (n) {
173 memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
174 memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
175 }
176
177 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
178 vfree(t->highs);
179
180 t->num_allocated = num;
181 t->highs = n_highs;
182 t->targets = n_targets;
183
184 return 0;
185}
186
Al Viroaeb5d722008-09-02 15:28:45 -0400187int dm_table_create(struct dm_table **result, fmode_t mode,
Mike Anderson1134e5a2006-03-27 01:17:54 -0800188 unsigned num_targets, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189{
Dmitry Monakhov094262d2007-10-19 22:38:51 +0100190 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
192 if (!t)
193 return -ENOMEM;
194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 INIT_LIST_HEAD(&t->devices);
NeilBrown9d357b02011-01-13 20:00:01 +0000196 INIT_LIST_HEAD(&t->target_callbacks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
198 if (!num_targets)
199 num_targets = KEYS_PER_NODE;
200
201 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
202
203 if (alloc_targets(t, num_targets)) {
204 kfree(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 return -ENOMEM;
206 }
207
208 t->mode = mode;
Mike Anderson1134e5a2006-03-27 01:17:54 -0800209 t->md = md;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 *result = t;
211 return 0;
212}
213
214static void free_devices(struct list_head *devices)
215{
216 struct list_head *tmp, *next;
217
Paul Jimenezafb24522008-02-08 02:09:59 +0000218 list_for_each_safe(tmp, next, devices) {
Mikulas Patocka82b15192008-10-10 13:37:09 +0100219 struct dm_dev_internal *dd =
220 list_entry(tmp, struct dm_dev_internal, list);
Jonthan Brassow1b6da752009-06-22 10:12:29 +0100221 DMWARN("dm_table_destroy: dm_put_device call missing for %s",
222 dd->dm_dev.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 kfree(dd);
224 }
225}
226
Mikulas Patockad5816872009-01-06 03:05:10 +0000227void dm_table_destroy(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228{
229 unsigned int i;
230
Alasdair G Kergona7940152009-12-10 23:52:23 +0000231 if (!t)
232 return;
233
Will Drewry26803b92010-08-12 04:14:03 +0100234 /* free the indexes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 if (t->depth >= 2)
236 vfree(t->index[t->depth - 2]);
237
238 /* free the targets */
239 for (i = 0; i < t->num_targets; i++) {
240 struct dm_target *tgt = t->targets + i;
241
242 if (tgt->type->dtr)
243 tgt->type->dtr(tgt);
244
245 dm_put_target_type(tgt->type);
246 }
247
248 vfree(t->highs);
249
250 /* free the device list */
Hannes Reinecke574ce072012-03-28 18:41:24 +0100251 free_devices(&t->devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100253 dm_free_md_mempools(t->mempools);
254
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 kfree(t);
256}
257
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258/*
259 * Checks to see if we need to extend highs or targets.
260 */
261static inline int check_space(struct dm_table *t)
262{
263 if (t->num_targets >= t->num_allocated)
264 return alloc_targets(t, t->num_allocated * 2);
265
266 return 0;
267}
268
269/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 * See if we've already got a device in the list.
271 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100272static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273{
Mikulas Patocka82b15192008-10-10 13:37:09 +0100274 struct dm_dev_internal *dd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
276 list_for_each_entry (dd, l, list)
Mikulas Patocka82b15192008-10-10 13:37:09 +0100277 if (dd->dm_dev.bdev->bd_dev == dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 return dd;
279
280 return NULL;
281}
282
283/*
284 * Open a device so we can use it as a map destination.
285 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100286static int open_dev(struct dm_dev_internal *d, dev_t dev,
287 struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288{
289 static char *_claim_ptr = "I belong to device-mapper";
290 struct block_device *bdev;
291
292 int r;
293
Mikulas Patocka82b15192008-10-10 13:37:09 +0100294 BUG_ON(d->dm_dev.bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
Tejun Heod4d77622010-11-13 11:55:18 +0100296 bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 if (IS_ERR(bdev))
298 return PTR_ERR(bdev);
Tejun Heoe09b4572010-11-13 11:55:17 +0100299
Tejun Heoe09b4572010-11-13 11:55:17 +0100300 r = bd_link_disk_holder(bdev, dm_disk(md));
301 if (r) {
Tejun Heoe525fd82010-11-13 11:55:17 +0100302 blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
Tejun Heoe09b4572010-11-13 11:55:17 +0100303 return r;
304 }
305
306 d->dm_dev.bdev = bdev;
307 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308}
309
310/*
311 * Close a device that we've been using.
312 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100313static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314{
Mikulas Patocka82b15192008-10-10 13:37:09 +0100315 if (!d->dm_dev.bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 return;
317
Tejun Heo49731ba2011-01-14 18:43:57 +0100318 bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
Tejun Heoe525fd82010-11-13 11:55:17 +0100319 blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
Mikulas Patocka82b15192008-10-10 13:37:09 +0100320 d->dm_dev.bdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321}
322
323/*
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100324 * If possible, this checks an area of a destination device is invalid.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 */
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100326static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
327 sector_t start, sector_t len, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328{
Milan Brozf4808ca2011-05-29 13:02:52 +0100329 struct request_queue *q;
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100330 struct queue_limits *limits = data;
331 struct block_device *bdev = dev->bdev;
332 sector_t dev_size =
333 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100334 unsigned short logical_block_size_sectors =
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100335 limits->logical_block_size >> SECTOR_SHIFT;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100336 char b[BDEVNAME_SIZE];
Mike Anderson2cd54d92007-05-09 02:32:57 -0700337
Milan Brozf4808ca2011-05-29 13:02:52 +0100338 /*
339 * Some devices exist without request functions,
340 * such as loop devices not yet bound to backing files.
341 * Forbid the use of such devices.
342 */
343 q = bdev_get_queue(bdev);
344 if (!q || !q->make_request_fn) {
345 DMWARN("%s: %s is not yet initialised: "
346 "start=%llu, len=%llu, dev_size=%llu",
347 dm_device_name(ti->table->md), bdevname(bdev, b),
348 (unsigned long long)start,
349 (unsigned long long)len,
350 (unsigned long long)dev_size);
351 return 1;
352 }
353
Mike Anderson2cd54d92007-05-09 02:32:57 -0700354 if (!dev_size)
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100355 return 0;
Mike Anderson2cd54d92007-05-09 02:32:57 -0700356
Mike Snitzer5dea2712009-07-23 20:30:42 +0100357 if ((start >= dev_size) || (start + len > dev_size)) {
Mike Snitzera963a952009-09-04 20:40:24 +0100358 DMWARN("%s: %s too small for target: "
359 "start=%llu, len=%llu, dev_size=%llu",
360 dm_device_name(ti->table->md), bdevname(bdev, b),
361 (unsigned long long)start,
362 (unsigned long long)len,
363 (unsigned long long)dev_size);
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100364 return 1;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100365 }
366
367 if (logical_block_size_sectors <= 1)
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100368 return 0;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100369
370 if (start & (logical_block_size_sectors - 1)) {
371 DMWARN("%s: start=%llu not aligned to h/w "
Mike Snitzera963a952009-09-04 20:40:24 +0100372 "logical block size %u of %s",
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100373 dm_device_name(ti->table->md),
374 (unsigned long long)start,
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100375 limits->logical_block_size, bdevname(bdev, b));
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100376 return 1;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100377 }
378
Mike Snitzer5dea2712009-07-23 20:30:42 +0100379 if (len & (logical_block_size_sectors - 1)) {
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100380 DMWARN("%s: len=%llu not aligned to h/w "
Mike Snitzera963a952009-09-04 20:40:24 +0100381 "logical block size %u of %s",
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100382 dm_device_name(ti->table->md),
Mike Snitzer5dea2712009-07-23 20:30:42 +0100383 (unsigned long long)len,
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100384 limits->logical_block_size, bdevname(bdev, b));
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100385 return 1;
Mike Snitzer02acc3a2009-06-22 10:12:30 +0100386 }
387
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +0100388 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389}
390
391/*
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100392 * This upgrades the mode on an already open dm_dev, being
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 * careful to leave things as they were if we fail to reopen the
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100394 * device and not to touch the existing bdev field in case
395 * it is accessed concurrently inside dm_table_any_congested().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 */
Al Viroaeb5d722008-09-02 15:28:45 -0400397static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
Mikulas Patocka82b15192008-10-10 13:37:09 +0100398 struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399{
400 int r;
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100401 struct dm_dev_internal dd_new, dd_old;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100403 dd_new = dd_old = *dd;
404
405 dd_new.dm_dev.mode |= new_mode;
406 dd_new.dm_dev.bdev = NULL;
407
408 r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
409 if (r)
410 return r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
Mikulas Patocka82b15192008-10-10 13:37:09 +0100412 dd->dm_dev.mode |= new_mode;
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100413 close_dev(&dd_old, md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
Alasdair G Kergon570b9d92009-04-02 19:55:28 +0100415 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416}
417
418/*
419 * Add a device to the list, or just increment the usage count if
420 * it's already present.
421 */
Mike Snitzer08649012011-08-02 12:32:04 +0100422int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
423 struct dm_dev **result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424{
425 int r;
Andrew Morton69a2ce72008-02-08 02:10:14 +0000426 dev_t uninitialized_var(dev);
Mikulas Patocka82b15192008-10-10 13:37:09 +0100427 struct dm_dev_internal *dd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 unsigned int major, minor;
Mike Snitzer08649012011-08-02 12:32:04 +0100429 struct dm_table *t = ti->table;
Mikulas Patocka31998ef2012-03-28 18:41:26 +0100430 char dummy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
Eric Sesterhenn547bc922006-03-26 18:22:50 +0200432 BUG_ON(!t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
Mikulas Patocka31998ef2012-03-28 18:41:26 +0100434 if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 /* Extract the major/minor numbers */
436 dev = MKDEV(major, minor);
437 if (MAJOR(dev) != major || MINOR(dev) != minor)
438 return -EOVERFLOW;
439 } else {
440 /* convert the path to a device */
Christoph Hellwig72e82642008-08-11 00:24:08 +0200441 struct block_device *bdev = lookup_bdev(path);
442
443 if (IS_ERR(bdev))
444 return PTR_ERR(bdev);
445 dev = bdev->bd_dev;
446 bdput(bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 }
448
449 dd = find_device(&t->devices, dev);
450 if (!dd) {
451 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
452 if (!dd)
453 return -ENOMEM;
454
Mikulas Patocka82b15192008-10-10 13:37:09 +0100455 dd->dm_dev.mode = mode;
456 dd->dm_dev.bdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800458 if ((r = open_dev(dd, dev, t->md))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 kfree(dd);
460 return r;
461 }
462
Mikulas Patocka82b15192008-10-10 13:37:09 +0100463 format_dev_t(dd->dm_dev.name, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464
465 atomic_set(&dd->count, 0);
466 list_add(&dd->list, &t->devices);
467
Mikulas Patocka82b15192008-10-10 13:37:09 +0100468 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800469 r = upgrade_mode(dd, mode, t->md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 if (r)
471 return r;
472 }
473 atomic_inc(&dd->count);
474
Mikulas Patocka82b15192008-10-10 13:37:09 +0100475 *result = &dd->dm_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 return 0;
477}
Mike Snitzer08649012011-08-02 12:32:04 +0100478EXPORT_SYMBOL(dm_get_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100480int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
Mike Snitzer5dea2712009-07-23 20:30:42 +0100481 sector_t start, sector_t len, void *data)
Bryn Reeves3cb40212006-10-03 01:15:42 -0700482{
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100483 struct queue_limits *limits = data;
484 struct block_device *bdev = dev->bdev;
Jens Axboe165125e2007-07-24 09:28:11 +0200485 struct request_queue *q = bdev_get_queue(bdev);
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +0100486 char b[BDEVNAME_SIZE];
487
488 if (unlikely(!q)) {
489 DMWARN("%s: Cannot set limits for nonexistent device %s",
490 dm_device_name(ti->table->md), bdevname(bdev, b));
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100491 return 0;
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +0100492 }
Bryn Reeves3cb40212006-10-03 01:15:42 -0700493
Martin K. Petersenb27d7f12010-01-11 03:21:50 -0500494 if (bdev_stack_limits(limits, bdev, start) < 0)
495 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
Mike Snitzera963a952009-09-04 20:40:24 +0100496 "physical_block_size=%u, logical_block_size=%u, "
497 "alignment_offset=%u, start=%llu",
498 dm_device_name(ti->table->md), bdevname(bdev, b),
499 q->limits.physical_block_size,
500 q->limits.logical_block_size,
501 q->limits.alignment_offset,
Martin K. Petersenb27d7f12010-01-11 03:21:50 -0500502 (unsigned long long) start << SECTOR_SHIFT);
Bryn Reeves3cb40212006-10-03 01:15:42 -0700503
Milan Broz9980c632008-07-21 12:00:39 +0100504 /*
505 * Check if merge fn is supported.
506 * If not we'll force DM to use PAGE_SIZE or
507 * smaller I/O, just to be safe.
Bryn Reeves3cb40212006-10-03 01:15:42 -0700508 */
Mikulas Patockad5b9dd02011-08-02 12:32:04 +0100509 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
Mike Snitzer72d4cd92010-12-17 08:34:20 +0100510 blk_limits_max_hw_sectors(limits,
511 (unsigned int) (PAGE_SIZE >> 9));
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100512 return 0;
Bryn Reeves3cb40212006-10-03 01:15:42 -0700513}
514EXPORT_SYMBOL_GPL(dm_set_device_limits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516/*
Mike Snitzer08649012011-08-02 12:32:04 +0100517 * Decrement a device's use count and remove it if necessary.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100519void dm_put_device(struct dm_target *ti, struct dm_dev *d)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520{
Mikulas Patocka82b15192008-10-10 13:37:09 +0100521 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
522 dm_dev);
523
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 if (atomic_dec_and_test(&dd->count)) {
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800525 close_dev(dd, ti->table->md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 list_del(&dd->list);
527 kfree(dd);
528 }
529}
Mike Snitzer08649012011-08-02 12:32:04 +0100530EXPORT_SYMBOL(dm_put_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531
532/*
533 * Checks to see if the target joins onto the end of the table.
534 */
535static int adjoin(struct dm_table *table, struct dm_target *ti)
536{
537 struct dm_target *prev;
538
539 if (!table->num_targets)
540 return !ti->begin;
541
542 prev = &table->targets[table->num_targets - 1];
543 return (ti->begin == (prev->begin + prev->len));
544}
545
546/*
547 * Used to dynamically allocate the arg array.
548 */
549static char **realloc_argv(unsigned *array_size, char **old_argv)
550{
551 char **argv;
552 unsigned new_size;
553
554 new_size = *array_size ? *array_size * 2 : 64;
555 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
556 if (argv) {
557 memcpy(argv, old_argv, *array_size * sizeof(*argv));
558 *array_size = new_size;
559 }
560
561 kfree(old_argv);
562 return argv;
563}
564
565/*
566 * Destructively splits up the argument list to pass to ctr.
567 */
568int dm_split_args(int *argc, char ***argvp, char *input)
569{
570 char *start, *end = input, *out, **argv = NULL;
571 unsigned array_size = 0;
572
573 *argc = 0;
David Teigland814d6862006-06-26 00:27:31 -0700574
575 if (!input) {
576 *argvp = NULL;
577 return 0;
578 }
579
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 argv = realloc_argv(&array_size, argv);
581 if (!argv)
582 return -ENOMEM;
583
584 while (1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 /* Skip whitespace */
André Goddard Rosae7d28602009-12-14 18:01:06 -0800586 start = skip_spaces(end);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588 if (!*start)
589 break; /* success, we hit the end */
590
591 /* 'out' is used to remove any back-quotes */
592 end = out = start;
593 while (*end) {
594 /* Everything apart from '\0' can be quoted */
595 if (*end == '\\' && *(end + 1)) {
596 *out++ = *(end + 1);
597 end += 2;
598 continue;
599 }
600
601 if (isspace(*end))
602 break; /* end of token */
603
604 *out++ = *end++;
605 }
606
607 /* have we already filled the array ? */
608 if ((*argc + 1) > array_size) {
609 argv = realloc_argv(&array_size, argv);
610 if (!argv)
611 return -ENOMEM;
612 }
613
614 /* we know this is whitespace */
615 if (*end)
616 end++;
617
618 /* terminate the string and put it in the array */
619 *out = '\0';
620 argv[*argc] = start;
621 (*argc)++;
622 }
623
624 *argvp = argv;
625 return 0;
626}
627
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100628/*
629 * Impose necessary and sufficient conditions on a devices's table such
630 * that any incoming bio which respects its logical_block_size can be
631 * processed successfully. If it falls across the boundary between
632 * two or more targets, the size of each piece it gets split into must
633 * be compatible with the logical_block_size of the target processing it.
634 */
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100635static int validate_hardware_logical_block_alignment(struct dm_table *table,
636 struct queue_limits *limits)
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100637{
638 /*
639 * This function uses arithmetic modulo the logical_block_size
640 * (in units of 512-byte sectors).
641 */
642 unsigned short device_logical_block_size_sects =
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100643 limits->logical_block_size >> SECTOR_SHIFT;
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100644
645 /*
646 * Offset of the start of the next table entry, mod logical_block_size.
647 */
648 unsigned short next_target_start = 0;
649
650 /*
651 * Given an aligned bio that extends beyond the end of a
652 * target, how many sectors must the next target handle?
653 */
654 unsigned short remaining = 0;
655
656 struct dm_target *uninitialized_var(ti);
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100657 struct queue_limits ti_limits;
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100658 unsigned i = 0;
659
660 /*
661 * Check each entry in the table in turn.
662 */
663 while (i < dm_table_get_num_targets(table)) {
664 ti = dm_table_get_target(table, i++);
665
Martin K. Petersenb1bd0552012-01-11 16:27:11 +0100666 blk_set_stacking_limits(&ti_limits);
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100667
668 /* combine all target devices' limits */
669 if (ti->type->iterate_devices)
670 ti->type->iterate_devices(ti, dm_set_device_limits,
671 &ti_limits);
672
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100673 /*
674 * If the remaining sectors fall entirely within this
675 * table entry are they compatible with its logical_block_size?
676 */
677 if (remaining < ti->len &&
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100678 remaining & ((ti_limits.logical_block_size >>
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100679 SECTOR_SHIFT) - 1))
680 break; /* Error */
681
682 next_target_start =
683 (unsigned short) ((next_target_start + ti->len) &
684 (device_logical_block_size_sects - 1));
685 remaining = next_target_start ?
686 device_logical_block_size_sects - next_target_start : 0;
687 }
688
689 if (remaining) {
690 DMWARN("%s: table line %u (start sect %llu len %llu) "
Mike Snitzera963a952009-09-04 20:40:24 +0100691 "not aligned to h/w logical block size %u",
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100692 dm_device_name(table->md), i,
693 (unsigned long long) ti->begin,
694 (unsigned long long) ti->len,
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100695 limits->logical_block_size);
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100696 return -EINVAL;
697 }
698
699 return 0;
700}
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702int dm_table_add_target(struct dm_table *t, const char *type,
703 sector_t start, sector_t len, char *params)
704{
705 int r = -EINVAL, argc;
706 char **argv;
707 struct dm_target *tgt;
708
Alasdair G Kergon3791e2f2011-10-31 20:19:00 +0000709 if (t->singleton) {
710 DMERR("%s: target type %s must appear alone in table",
711 dm_device_name(t->md), t->targets->type->name);
712 return -EINVAL;
713 }
714
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 if ((r = check_space(t)))
716 return r;
717
718 tgt = t->targets + t->num_targets;
719 memset(tgt, 0, sizeof(*tgt));
720
721 if (!len) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700722 DMERR("%s: zero-length target", dm_device_name(t->md));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 return -EINVAL;
724 }
725
726 tgt->type = dm_get_target_type(type);
727 if (!tgt->type) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700728 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
729 type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 return -EINVAL;
731 }
732
Alasdair G Kergon3791e2f2011-10-31 20:19:00 +0000733 if (dm_target_needs_singleton(tgt->type)) {
734 if (t->num_targets) {
735 DMERR("%s: target type %s must appear alone in table",
736 dm_device_name(t->md), type);
737 return -EINVAL;
738 }
739 t->singleton = 1;
740 }
741
Alasdair G Kergoncc6cbe12011-10-31 20:19:02 +0000742 if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
743 DMERR("%s: target type %s may not be included in read-only tables",
744 dm_device_name(t->md), type);
745 return -EINVAL;
746 }
747
Alasdair G Kergon36a04562011-10-31 20:19:04 +0000748 if (t->immutable_target_type) {
749 if (t->immutable_target_type != tgt->type) {
750 DMERR("%s: immutable target type %s cannot be mixed with other target types",
751 dm_device_name(t->md), t->immutable_target_type->name);
752 return -EINVAL;
753 }
754 } else if (dm_target_is_immutable(tgt->type)) {
755 if (t->num_targets) {
756 DMERR("%s: immutable target type %s cannot be mixed with other target types",
757 dm_device_name(t->md), tgt->type->name);
758 return -EINVAL;
759 }
760 t->immutable_target_type = tgt->type;
761 }
762
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 tgt->table = t;
764 tgt->begin = start;
765 tgt->len = len;
766 tgt->error = "Unknown error";
767
768 /*
769 * Does this target adjoin the previous one ?
770 */
771 if (!adjoin(t, tgt)) {
772 tgt->error = "Gap in table";
773 r = -EINVAL;
774 goto bad;
775 }
776
777 r = dm_split_args(&argc, &argv, params);
778 if (r) {
779 tgt->error = "couldn't split parameters (insufficient memory)";
780 goto bad;
781 }
782
783 r = tgt->type->ctr(tgt, argc, argv);
784 kfree(argv);
785 if (r)
786 goto bad;
787
788 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
789
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +0000790 if (!tgt->num_discard_bios && tgt->discards_supported)
791 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
Mike Snitzer936688d2011-08-02 12:32:01 +0100792 dm_device_name(t->md), type);
Mike Snitzer5ae89a82010-08-12 04:14:08 +0100793
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 return 0;
795
796 bad:
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700797 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 dm_put_target_type(tgt->type);
799 return r;
800}
801
Mike Snitzer498f0102011-08-02 12:32:04 +0100802/*
803 * Target argument parsing helpers.
804 */
805static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
806 unsigned *value, char **error, unsigned grouped)
807{
808 const char *arg_str = dm_shift_arg(arg_set);
Mikulas Patocka31998ef2012-03-28 18:41:26 +0100809 char dummy;
Mike Snitzer498f0102011-08-02 12:32:04 +0100810
811 if (!arg_str ||
Mikulas Patocka31998ef2012-03-28 18:41:26 +0100812 (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
Mike Snitzer498f0102011-08-02 12:32:04 +0100813 (*value < arg->min) ||
814 (*value > arg->max) ||
815 (grouped && arg_set->argc < *value)) {
816 *error = arg->error;
817 return -EINVAL;
818 }
819
820 return 0;
821}
822
823int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
824 unsigned *value, char **error)
825{
826 return validate_next_arg(arg, arg_set, value, error, 0);
827}
828EXPORT_SYMBOL(dm_read_arg);
829
830int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
831 unsigned *value, char **error)
832{
833 return validate_next_arg(arg, arg_set, value, error, 1);
834}
835EXPORT_SYMBOL(dm_read_arg_group);
836
837const char *dm_shift_arg(struct dm_arg_set *as)
838{
839 char *r;
840
841 if (as->argc) {
842 as->argc--;
843 r = *as->argv;
844 as->argv++;
845 return r;
846 }
847
848 return NULL;
849}
850EXPORT_SYMBOL(dm_shift_arg);
851
852void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
853{
854 BUG_ON(as->argc < num_args);
855 as->argc -= num_args;
856 as->argv += num_args;
857}
858EXPORT_SYMBOL(dm_consume_args);
859
Will Drewry26803b92010-08-12 04:14:03 +0100860static int dm_table_set_type(struct dm_table *t)
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100861{
862 unsigned i;
Mike Snitzer169e2cc2013-08-22 18:21:38 -0400863 unsigned bio_based = 0, request_based = 0, hybrid = 0;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100864 struct dm_target *tgt;
865 struct dm_dev_internal *dd;
866 struct list_head *devices;
Mike Snitzer169e2cc2013-08-22 18:21:38 -0400867 unsigned live_md_type;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100868
869 for (i = 0; i < t->num_targets; i++) {
870 tgt = t->targets + i;
Mike Snitzer169e2cc2013-08-22 18:21:38 -0400871 if (dm_target_hybrid(tgt))
872 hybrid = 1;
873 else if (dm_target_request_based(tgt))
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100874 request_based = 1;
875 else
876 bio_based = 1;
877
878 if (bio_based && request_based) {
879 DMWARN("Inconsistent table: different target types"
880 " can't be mixed up");
881 return -EINVAL;
882 }
883 }
884
Mike Snitzer169e2cc2013-08-22 18:21:38 -0400885 if (hybrid && !bio_based && !request_based) {
886 /*
887 * The targets can work either way.
888 * Determine the type from the live device.
889 * Default to bio-based if device is new.
890 */
Mike Snitzer169e2cc2013-08-22 18:21:38 -0400891 live_md_type = dm_get_md_type(t->md);
Mike Snitzer169e2cc2013-08-22 18:21:38 -0400892 if (live_md_type == DM_TYPE_REQUEST_BASED)
893 request_based = 1;
894 else
895 bio_based = 1;
896 }
897
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100898 if (bio_based) {
899 /* We must use this table as bio-based */
900 t->type = DM_TYPE_BIO_BASED;
901 return 0;
902 }
903
904 BUG_ON(!request_based); /* No targets in this table */
905
906 /* Non-request-stackable devices can't be used for request-based dm */
907 devices = dm_table_get_devices(t);
908 list_for_each_entry(dd, devices, list) {
909 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
910 DMWARN("table load rejected: including"
911 " non-request-stackable devices");
912 return -EINVAL;
913 }
914 }
915
916 /*
917 * Request-based dm supports only tables that have a single target now.
918 * To support multiple targets, request splitting support is needed,
919 * and that needs lots of changes in the block-layer.
920 * (e.g. request completion process for partial completion.)
921 */
922 if (t->num_targets > 1) {
923 DMWARN("Request-based dm doesn't support multiple targets yet");
924 return -EINVAL;
925 }
926
927 t->type = DM_TYPE_REQUEST_BASED;
928
929 return 0;
930}
931
932unsigned dm_table_get_type(struct dm_table *t)
933{
934 return t->type;
935}
936
Alasdair G Kergon36a04562011-10-31 20:19:04 +0000937struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
938{
939 return t->immutable_target_type;
940}
941
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100942bool dm_table_request_based(struct dm_table *t)
943{
944 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
945}
946
947int dm_table_alloc_md_mempools(struct dm_table *t)
948{
949 unsigned type = dm_table_get_type(t);
Mikulas Patockac0820cf2012-12-21 20:23:38 +0000950 unsigned per_bio_data_size = 0;
951 struct dm_target *tgt;
952 unsigned i;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100953
954 if (unlikely(type == DM_TYPE_NONE)) {
955 DMWARN("no table type is set, can't allocate mempools");
956 return -EINVAL;
957 }
958
Mikulas Patockac0820cf2012-12-21 20:23:38 +0000959 if (type == DM_TYPE_BIO_BASED)
960 for (i = 0; i < t->num_targets; i++) {
961 tgt = t->targets + i;
962 per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
963 }
964
965 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported, per_bio_data_size);
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100966 if (!t->mempools)
967 return -ENOMEM;
968
969 return 0;
970}
971
972void dm_table_free_md_mempools(struct dm_table *t)
973{
974 dm_free_md_mempools(t->mempools);
975 t->mempools = NULL;
976}
977
978struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
979{
980 return t->mempools;
981}
982
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983static int setup_indexes(struct dm_table *t)
984{
985 int i;
986 unsigned int total = 0;
987 sector_t *indexes;
988
989 /* allocate the space for *all* the indexes */
990 for (i = t->depth - 2; i >= 0; i--) {
991 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
992 total += t->counts[i];
993 }
994
995 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
996 if (!indexes)
997 return -ENOMEM;
998
999 /* set up internal nodes, bottom-up */
Jun'ichi Nomura82d601d2008-02-08 02:10:04 +00001000 for (i = t->depth - 2; i >= 0; i--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 t->index[i] = indexes;
1002 indexes += (KEYS_PER_NODE * t->counts[i]);
1003 setup_btree_index(i, t);
1004 }
1005
1006 return 0;
1007}
1008
1009/*
1010 * Builds the btree to index the map.
1011 */
Will Drewry26803b92010-08-12 04:14:03 +01001012static int dm_table_build_index(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013{
1014 int r = 0;
1015 unsigned int leaf_nodes;
1016
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 /* how many indexes will the btree have ? */
1018 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1019 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1020
1021 /* leaf layer has already been set up */
1022 t->counts[t->depth - 1] = leaf_nodes;
1023 t->index[t->depth - 1] = t->highs;
1024
1025 if (t->depth >= 2)
1026 r = setup_indexes(t);
1027
1028 return r;
1029}
1030
Will Drewry26803b92010-08-12 04:14:03 +01001031/*
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001032 * Get a disk whose integrity profile reflects the table's profile.
1033 * If %match_all is true, all devices' profiles must match.
1034 * If %match_all is false, all devices must at least have an
1035 * allocated integrity profile; but uninitialized is ok.
1036 * Returns NULL if integrity support was inconsistent or unavailable.
1037 */
1038static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1039 bool match_all)
1040{
1041 struct list_head *devices = dm_table_get_devices(t);
1042 struct dm_dev_internal *dd = NULL;
1043 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1044
1045 list_for_each_entry(dd, devices, list) {
1046 template_disk = dd->dm_dev.bdev->bd_disk;
1047 if (!blk_get_integrity(template_disk))
1048 goto no_integrity;
1049 if (!match_all && !blk_integrity_is_initialized(template_disk))
1050 continue; /* skip uninitialized profiles */
1051 else if (prev_disk &&
1052 blk_integrity_compare(prev_disk, template_disk) < 0)
1053 goto no_integrity;
1054 prev_disk = template_disk;
1055 }
1056
1057 return template_disk;
1058
1059no_integrity:
1060 if (prev_disk)
1061 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1062 dm_device_name(t->md),
1063 prev_disk->disk_name,
1064 template_disk->disk_name);
1065 return NULL;
1066}
1067
1068/*
Will Drewry26803b92010-08-12 04:14:03 +01001069 * Register the mapped device for blk_integrity support if
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001070 * the underlying devices have an integrity profile. But all devices
1071 * may not have matching profiles (checking all devices isn't reliable
1072 * during table load because this table may use other DM device(s) which
1073 * must be resumed before they will have an initialized integity profile).
1074 * Stacked DM devices force a 2 stage integrity profile validation:
1075 * 1 - during load, validate all initialized integrity profiles match
1076 * 2 - during resume, validate all integrity profiles match
Will Drewry26803b92010-08-12 04:14:03 +01001077 */
1078static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1079{
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001080 struct gendisk *template_disk = NULL;
Will Drewry26803b92010-08-12 04:14:03 +01001081
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001082 template_disk = dm_table_get_integrity_disk(t, false);
1083 if (!template_disk)
1084 return 0;
Will Drewry26803b92010-08-12 04:14:03 +01001085
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001086 if (!blk_integrity_is_initialized(dm_disk(md))) {
1087 t->integrity_supported = 1;
1088 return blk_integrity_register(dm_disk(md), NULL);
1089 }
1090
1091 /*
1092 * If DM device already has an initalized integrity
1093 * profile the new profile should not conflict.
1094 */
1095 if (blk_integrity_is_initialized(template_disk) &&
1096 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1097 DMWARN("%s: conflict with existing integrity profile: "
1098 "%s profile mismatch",
1099 dm_device_name(t->md),
1100 template_disk->disk_name);
1101 return 1;
1102 }
1103
1104 /* Preserve existing initialized integrity profile */
1105 t->integrity_supported = 1;
Will Drewry26803b92010-08-12 04:14:03 +01001106 return 0;
1107}
1108
1109/*
1110 * Prepares the table for use by building the indices,
1111 * setting the type, and allocating mempools.
1112 */
1113int dm_table_complete(struct dm_table *t)
1114{
1115 int r;
1116
1117 r = dm_table_set_type(t);
1118 if (r) {
1119 DMERR("unable to set table type");
1120 return r;
1121 }
1122
1123 r = dm_table_build_index(t);
1124 if (r) {
1125 DMERR("unable to build btrees");
1126 return r;
1127 }
1128
1129 r = dm_table_prealloc_integrity(t, t->md);
1130 if (r) {
1131 DMERR("could not register integrity profile.");
1132 return r;
1133 }
1134
1135 r = dm_table_alloc_md_mempools(t);
1136 if (r)
1137 DMERR("unable to allocate mempools");
1138
1139 return r;
1140}
1141
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001142static DEFINE_MUTEX(_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143void dm_table_event_callback(struct dm_table *t,
1144 void (*fn)(void *), void *context)
1145{
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001146 mutex_lock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 t->event_fn = fn;
1148 t->event_context = context;
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001149 mutex_unlock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150}
1151
1152void dm_table_event(struct dm_table *t)
1153{
1154 /*
1155 * You can no longer call dm_table_event() from interrupt
1156 * context, use a bottom half instead.
1157 */
1158 BUG_ON(in_interrupt());
1159
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001160 mutex_lock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 if (t->event_fn)
1162 t->event_fn(t->event_context);
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001163 mutex_unlock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164}
Mike Snitzer08649012011-08-02 12:32:04 +01001165EXPORT_SYMBOL(dm_table_event);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166
1167sector_t dm_table_get_size(struct dm_table *t)
1168{
1169 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1170}
Mike Snitzer08649012011-08-02 12:32:04 +01001171EXPORT_SYMBOL(dm_table_get_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172
1173struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1174{
Milan Broz14353532006-06-26 00:27:27 -07001175 if (index >= t->num_targets)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176 return NULL;
1177
1178 return t->targets + index;
1179}
1180
1181/*
1182 * Search the btree for the correct target.
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001183 *
1184 * Caller should check returned pointer with dm_target_is_valid()
1185 * to trap I/O beyond end of device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186 */
1187struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1188{
1189 unsigned int l, n = 0, k = 0;
1190 sector_t *node;
1191
1192 for (l = 0; l < t->depth; l++) {
1193 n = get_child(n, k);
1194 node = get_node(t, l, n);
1195
1196 for (k = 0; k < KEYS_PER_NODE; k++)
1197 if (node[k] >= sector)
1198 break;
1199 }
1200
1201 return &t->targets[(KEYS_PER_NODE * n) + k];
1202}
1203
Mike Snitzer3ae70652012-09-26 23:45:45 +01001204static int count_device(struct dm_target *ti, struct dm_dev *dev,
1205 sector_t start, sector_t len, void *data)
1206{
1207 unsigned *num_devices = data;
1208
1209 (*num_devices)++;
1210
1211 return 0;
1212}
1213
1214/*
1215 * Check whether a table has no data devices attached using each
1216 * target's iterate_devices method.
1217 * Returns false if the result is unknown because a target doesn't
1218 * support iterate_devices.
1219 */
1220bool dm_table_has_no_data_devices(struct dm_table *table)
1221{
1222 struct dm_target *uninitialized_var(ti);
1223 unsigned i = 0, num_devices = 0;
1224
1225 while (i < dm_table_get_num_targets(table)) {
1226 ti = dm_table_get_target(table, i++);
1227
1228 if (!ti->type->iterate_devices)
1229 return false;
1230
1231 ti->type->iterate_devices(ti, count_device, &num_devices);
1232 if (num_devices)
1233 return false;
1234 }
1235
1236 return true;
1237}
1238
Martin K. Petersen9c470082009-04-09 00:27:12 +01001239/*
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001240 * Establish the new table's queue_limits and validate them.
1241 */
1242int dm_calculate_queue_limits(struct dm_table *table,
1243 struct queue_limits *limits)
1244{
1245 struct dm_target *uninitialized_var(ti);
1246 struct queue_limits ti_limits;
1247 unsigned i = 0;
1248
Martin K. Petersenb1bd0552012-01-11 16:27:11 +01001249 blk_set_stacking_limits(limits);
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001250
1251 while (i < dm_table_get_num_targets(table)) {
Martin K. Petersenb1bd0552012-01-11 16:27:11 +01001252 blk_set_stacking_limits(&ti_limits);
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001253
1254 ti = dm_table_get_target(table, i++);
1255
1256 if (!ti->type->iterate_devices)
1257 goto combine_limits;
1258
1259 /*
1260 * Combine queue limits of all the devices this target uses.
1261 */
1262 ti->type->iterate_devices(ti, dm_set_device_limits,
1263 &ti_limits);
1264
Mike Snitzer40bea432009-09-04 20:40:25 +01001265 /* Set I/O hints portion of queue limits */
1266 if (ti->type->io_hints)
1267 ti->type->io_hints(ti, &ti_limits);
1268
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001269 /*
1270 * Check each device area is consistent with the target's
1271 * overall queue limits.
1272 */
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +01001273 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1274 &ti_limits))
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001275 return -EINVAL;
1276
1277combine_limits:
1278 /*
1279 * Merge this target's queue limits into the overall limits
1280 * for the table.
1281 */
1282 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
Martin K. Petersenb27d7f12010-01-11 03:21:50 -05001283 DMWARN("%s: adding target device "
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001284 "(start sect %llu len %llu) "
Martin K. Petersenb27d7f12010-01-11 03:21:50 -05001285 "caused an alignment inconsistency",
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001286 dm_device_name(table->md),
1287 (unsigned long long) ti->begin,
1288 (unsigned long long) ti->len);
1289 }
1290
1291 return validate_hardware_logical_block_alignment(table, limits);
1292}
1293
1294/*
Martin K. Petersen9c470082009-04-09 00:27:12 +01001295 * Set the integrity profile for this device if all devices used have
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001296 * matching profiles. We're quite deep in the resume path but still
1297 * don't know if all devices (particularly DM devices this device
1298 * may be stacked on) have matching profiles. Even if the profiles
1299 * don't match we have no way to fail (to resume) at this point.
Martin K. Petersen9c470082009-04-09 00:27:12 +01001300 */
1301static void dm_table_set_integrity(struct dm_table *t)
1302{
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001303 struct gendisk *template_disk = NULL;
Martin K. Petersen9c470082009-04-09 00:27:12 +01001304
1305 if (!blk_get_integrity(dm_disk(t->md)))
1306 return;
1307
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001308 template_disk = dm_table_get_integrity_disk(t, true);
Mike Snitzer876fbba2011-09-25 23:26:17 +01001309 if (template_disk)
1310 blk_integrity_register(dm_disk(t->md),
1311 blk_get_integrity(template_disk));
1312 else if (blk_integrity_is_initialized(dm_disk(t->md)))
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001313 DMWARN("%s: device no longer has a valid integrity profile",
1314 dm_device_name(t->md));
Mike Snitzer876fbba2011-09-25 23:26:17 +01001315 else
1316 DMWARN("%s: unable to establish an integrity profile",
1317 dm_device_name(t->md));
Martin K. Petersen9c470082009-04-09 00:27:12 +01001318}
1319
Mike Snitzered8b7522011-08-02 12:32:08 +01001320static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1321 sector_t start, sector_t len, void *data)
1322{
1323 unsigned flush = (*(unsigned *)data);
1324 struct request_queue *q = bdev_get_queue(dev->bdev);
1325
1326 return q && (q->flush_flags & flush);
1327}
1328
1329static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1330{
1331 struct dm_target *ti;
1332 unsigned i = 0;
1333
1334 /*
1335 * Require at least one underlying device to support flushes.
1336 * t->devices includes internal dm devices such as mirror logs
1337 * so we need to use iterate_devices here, which targets
1338 * supporting flushes must provide.
1339 */
1340 while (i < dm_table_get_num_targets(t)) {
1341 ti = dm_table_get_target(t, i++);
1342
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00001343 if (!ti->num_flush_bios)
Mike Snitzered8b7522011-08-02 12:32:08 +01001344 continue;
1345
Joe Thornber0e9c24e2012-07-27 15:08:07 +01001346 if (ti->flush_supported)
1347 return 1;
1348
Mike Snitzered8b7522011-08-02 12:32:08 +01001349 if (ti->type->iterate_devices &&
1350 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1351 return 1;
1352 }
1353
1354 return 0;
1355}
1356
Milan Broz983c7db2011-09-25 23:26:21 +01001357static bool dm_table_discard_zeroes_data(struct dm_table *t)
1358{
1359 struct dm_target *ti;
1360 unsigned i = 0;
1361
1362 /* Ensure that all targets supports discard_zeroes_data. */
1363 while (i < dm_table_get_num_targets(t)) {
1364 ti = dm_table_get_target(t, i++);
1365
1366 if (ti->discard_zeroes_data_unsupported)
1367 return 0;
1368 }
1369
1370 return 1;
1371}
1372
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001373static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1374 sector_t start, sector_t len, void *data)
1375{
1376 struct request_queue *q = bdev_get_queue(dev->bdev);
1377
1378 return q && blk_queue_nonrot(q);
1379}
1380
Milan Brozc3c4555e2012-09-26 23:45:43 +01001381static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1382 sector_t start, sector_t len, void *data)
1383{
1384 struct request_queue *q = bdev_get_queue(dev->bdev);
1385
1386 return q && !blk_queue_add_random(q);
1387}
1388
1389static bool dm_table_all_devices_attribute(struct dm_table *t,
1390 iterate_devices_callout_fn func)
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001391{
1392 struct dm_target *ti;
1393 unsigned i = 0;
1394
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001395 while (i < dm_table_get_num_targets(t)) {
1396 ti = dm_table_get_target(t, i++);
1397
1398 if (!ti->type->iterate_devices ||
Milan Brozc3c4555e2012-09-26 23:45:43 +01001399 !ti->type->iterate_devices(ti, func, NULL))
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001400 return 0;
1401 }
1402
1403 return 1;
1404}
1405
Mike Snitzerd54eaa52012-12-21 20:23:36 +00001406static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1407 sector_t start, sector_t len, void *data)
1408{
1409 struct request_queue *q = bdev_get_queue(dev->bdev);
1410
1411 return q && !q->limits.max_write_same_sectors;
1412}
1413
1414static bool dm_table_supports_write_same(struct dm_table *t)
1415{
1416 struct dm_target *ti;
1417 unsigned i = 0;
1418
1419 while (i < dm_table_get_num_targets(t)) {
1420 ti = dm_table_get_target(t, i++);
1421
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00001422 if (!ti->num_write_same_bios)
Mike Snitzerd54eaa52012-12-21 20:23:36 +00001423 return false;
1424
1425 if (!ti->type->iterate_devices ||
Mike Snitzerdc019b22013-05-10 14:37:16 +01001426 ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
Mike Snitzerd54eaa52012-12-21 20:23:36 +00001427 return false;
1428 }
1429
1430 return true;
1431}
1432
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001433void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1434 struct queue_limits *limits)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435{
Mike Snitzered8b7522011-08-02 12:32:08 +01001436 unsigned flush = 0;
1437
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 /*
Mike Snitzer11977642009-06-22 10:12:32 +01001439 * Copy table's limits to the DM device's request_queue
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440 */
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001441 q->limits = *limits;
Jens Axboec9a3f6d2008-04-29 19:12:35 +02001442
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001443 if (!dm_table_supports_discards(t))
1444 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1445 else
1446 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1447
Mike Snitzered8b7522011-08-02 12:32:08 +01001448 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1449 flush |= REQ_FLUSH;
1450 if (dm_table_supports_flush(t, REQ_FUA))
1451 flush |= REQ_FUA;
1452 }
1453 blk_queue_flush(q, flush);
1454
Milan Broz983c7db2011-09-25 23:26:21 +01001455 if (!dm_table_discard_zeroes_data(t))
1456 q->limits.discard_zeroes_data = 0;
1457
Milan Brozc3c4555e2012-09-26 23:45:43 +01001458 /* Ensure that all underlying devices are non-rotational. */
1459 if (dm_table_all_devices_attribute(t, device_is_nonrot))
Mandeep Singh Baines4693c9662011-10-31 20:18:50 +00001460 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1461 else
1462 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1463
Mike Snitzerd54eaa52012-12-21 20:23:36 +00001464 if (!dm_table_supports_write_same(t))
1465 q->limits.max_write_same_sectors = 0;
Mike Snitzerc1a94672012-12-21 20:23:30 +00001466
Martin K. Petersen9c470082009-04-09 00:27:12 +01001467 dm_table_set_integrity(t);
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001468
1469 /*
Milan Brozc3c4555e2012-09-26 23:45:43 +01001470 * Determine whether or not this queue's I/O timings contribute
1471 * to the entropy pool, Only request-based targets use this.
1472 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1473 * have it set.
1474 */
1475 if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1476 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1477
1478 /*
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001479 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1480 * visible to other CPUs because, once the flag is set, incoming bios
1481 * are processed by request-based dm, which refers to the queue
1482 * settings.
1483 * Until the flag set, bios are passed to bio-based dm and queued to
1484 * md->deferred where queue settings are not needed yet.
1485 * Those bios are passed to request-based dm at the resume time.
1486 */
1487 smp_mb();
1488 if (dm_table_request_based(t))
1489 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490}
1491
1492unsigned int dm_table_get_num_targets(struct dm_table *t)
1493{
1494 return t->num_targets;
1495}
1496
1497struct list_head *dm_table_get_devices(struct dm_table *t)
1498{
1499 return &t->devices;
1500}
1501
Al Viroaeb5d722008-09-02 15:28:45 -04001502fmode_t dm_table_get_mode(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503{
1504 return t->mode;
1505}
Mike Snitzer08649012011-08-02 12:32:04 +01001506EXPORT_SYMBOL(dm_table_get_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507
1508static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1509{
1510 int i = t->num_targets;
1511 struct dm_target *ti = t->targets;
1512
1513 while (i--) {
1514 if (postsuspend) {
1515 if (ti->type->postsuspend)
1516 ti->type->postsuspend(ti);
1517 } else if (ti->type->presuspend)
1518 ti->type->presuspend(ti);
1519
1520 ti++;
1521 }
1522}
1523
1524void dm_table_presuspend_targets(struct dm_table *t)
1525{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07001526 if (!t)
1527 return;
1528
Adrian Bunke8488d02008-04-24 22:10:51 +01001529 suspend_targets(t, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530}
1531
1532void dm_table_postsuspend_targets(struct dm_table *t)
1533{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07001534 if (!t)
1535 return;
1536
Adrian Bunke8488d02008-04-24 22:10:51 +01001537 suspend_targets(t, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001538}
1539
Milan Broz8757b772006-10-03 01:15:36 -07001540int dm_table_resume_targets(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001541{
Milan Broz8757b772006-10-03 01:15:36 -07001542 int i, r = 0;
1543
1544 for (i = 0; i < t->num_targets; i++) {
1545 struct dm_target *ti = t->targets + i;
1546
1547 if (!ti->type->preresume)
1548 continue;
1549
1550 r = ti->type->preresume(ti);
1551 if (r)
1552 return r;
1553 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554
1555 for (i = 0; i < t->num_targets; i++) {
1556 struct dm_target *ti = t->targets + i;
1557
1558 if (ti->type->resume)
1559 ti->type->resume(ti);
1560 }
Milan Broz8757b772006-10-03 01:15:36 -07001561
1562 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563}
1564
NeilBrown9d357b02011-01-13 20:00:01 +00001565void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1566{
1567 list_add(&cb->list, &t->target_callbacks);
1568}
1569EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1570
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1572{
Mikulas Patocka82b15192008-10-10 13:37:09 +01001573 struct dm_dev_internal *dd;
Paul Jimenezafb24522008-02-08 02:09:59 +00001574 struct list_head *devices = dm_table_get_devices(t);
NeilBrown9d357b02011-01-13 20:00:01 +00001575 struct dm_target_callbacks *cb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001576 int r = 0;
1577
Paul Jimenezafb24522008-02-08 02:09:59 +00001578 list_for_each_entry(dd, devices, list) {
Mikulas Patocka82b15192008-10-10 13:37:09 +01001579 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +01001580 char b[BDEVNAME_SIZE];
1581
1582 if (likely(q))
1583 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1584 else
1585 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1586 dm_device_name(t->md),
1587 bdevname(dd->dm_dev.bdev, b));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588 }
1589
NeilBrown9d357b02011-01-13 20:00:01 +00001590 list_for_each_entry(cb, &t->target_callbacks, list)
1591 if (cb->congested_fn)
1592 r |= cb->congested_fn(cb, bdi_bits);
1593
Linus Torvalds1da177e2005-04-16 15:20:36 -07001594 return r;
1595}
1596
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001597int dm_table_any_busy_target(struct dm_table *t)
1598{
1599 unsigned i;
1600 struct dm_target *ti;
1601
1602 for (i = 0; i < t->num_targets; i++) {
1603 ti = t->targets + i;
1604 if (ti->type->busy && ti->type->busy(ti))
1605 return 1;
1606 }
1607
1608 return 0;
1609}
1610
Mike Anderson1134e5a2006-03-27 01:17:54 -08001611struct mapped_device *dm_table_get_md(struct dm_table *t)
1612{
Mike Anderson1134e5a2006-03-27 01:17:54 -08001613 return t->md;
1614}
Mike Snitzer08649012011-08-02 12:32:04 +01001615EXPORT_SYMBOL(dm_table_get_md);
Mike Anderson1134e5a2006-03-27 01:17:54 -08001616
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001617static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1618 sector_t start, sector_t len, void *data)
1619{
1620 struct request_queue *q = bdev_get_queue(dev->bdev);
1621
1622 return q && blk_queue_discard(q);
1623}
1624
1625bool dm_table_supports_discards(struct dm_table *t)
1626{
1627 struct dm_target *ti;
1628 unsigned i = 0;
1629
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001630 /*
Mike Snitzer4c259322011-05-29 12:52:55 +01001631 * Unless any target used by the table set discards_supported,
1632 * require at least one underlying device to support discards.
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001633 * t->devices includes internal dm devices such as mirror logs
1634 * so we need to use iterate_devices here, which targets
Mike Snitzer936688d2011-08-02 12:32:01 +01001635 * supporting discard selectively must provide.
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001636 */
1637 while (i < dm_table_get_num_targets(t)) {
1638 ti = dm_table_get_target(t, i++);
1639
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00001640 if (!ti->num_discard_bios)
Mike Snitzer936688d2011-08-02 12:32:01 +01001641 continue;
1642
Mike Snitzer4c259322011-05-29 12:52:55 +01001643 if (ti->discards_supported)
1644 return 1;
1645
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001646 if (ti->type->iterate_devices &&
1647 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1648 return 1;
1649 }
1650
1651 return 0;
1652}