blob: 986b8754bb0813c59fb22a0feae7083740378f72 [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
Martin K. Petersena91a2782011-03-17 11:11:05 +010057 unsigned integrity_supported:1;
Mike Snitzer5ae89a82010-08-12 04:14:08 +010058
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 /*
60 * Indicates the rw permissions for the new logical
61 * device. This should be a combination of FMODE_READ
62 * and FMODE_WRITE.
63 */
Al Viroaeb5d722008-09-02 15:28:45 -040064 fmode_t mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66 /* a list of devices used by this table */
67 struct list_head devices;
68
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 /* events get handed up using this callback */
70 void (*event_fn)(void *);
71 void *event_context;
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +010072
73 struct dm_md_mempools *mempools;
NeilBrown9d357b02011-01-13 20:00:01 +000074
75 struct list_head target_callbacks;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076};
77
78/*
79 * Similar to ceiling(log_size(n))
80 */
81static unsigned int int_log(unsigned int n, unsigned int base)
82{
83 int result = 0;
84
85 while (n > 1) {
86 n = dm_div_up(n, base);
87 result++;
88 }
89
90 return result;
91}
92
93/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 * Calculate the index of the child node of the n'th node k'th key.
95 */
96static inline unsigned int get_child(unsigned int n, unsigned int k)
97{
98 return (n * CHILDREN_PER_NODE) + k;
99}
100
101/*
102 * Return the n'th node of level l from table t.
103 */
104static inline sector_t *get_node(struct dm_table *t,
105 unsigned int l, unsigned int n)
106{
107 return t->index[l] + (n * KEYS_PER_NODE);
108}
109
110/*
111 * Return the highest key that you could lookup from the n'th
112 * node on level l of the btree.
113 */
114static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
115{
116 for (; l < t->depth - 1; l++)
117 n = get_child(n, CHILDREN_PER_NODE - 1);
118
119 if (n >= t->counts[l])
120 return (sector_t) - 1;
121
122 return get_node(t, l, n)[KEYS_PER_NODE - 1];
123}
124
125/*
126 * Fills in a level of the btree based on the highs of the level
127 * below it.
128 */
129static int setup_btree_index(unsigned int l, struct dm_table *t)
130{
131 unsigned int n, k;
132 sector_t *node;
133
134 for (n = 0U; n < t->counts[l]; n++) {
135 node = get_node(t, l, n);
136
137 for (k = 0U; k < KEYS_PER_NODE; k++)
138 node[k] = high(t, l + 1, get_child(n, k));
139 }
140
141 return 0;
142}
143
144void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
145{
146 unsigned long size;
147 void *addr;
148
149 /*
150 * Check that we're not going to overflow.
151 */
152 if (nmemb > (ULONG_MAX / elem_size))
153 return NULL;
154
155 size = nmemb * elem_size;
Joe Perchese29e65a2011-08-02 12:32:02 +0100156 addr = vzalloc(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158 return addr;
159}
Mike Snitzer08649012011-08-02 12:32:04 +0100160EXPORT_SYMBOL(dm_vcalloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162/*
163 * highs, and targets are managed as dynamic arrays during a
164 * table load.
165 */
166static int alloc_targets(struct dm_table *t, unsigned int num)
167{
168 sector_t *n_highs;
169 struct dm_target *n_targets;
170 int n = t->num_targets;
171
172 /*
173 * Allocate both the target array and offset array at once.
Jun'ichi Nomura512875b2007-12-13 14:15:25 +0000174 * Append an empty entry to catch sectors beyond the end of
175 * the device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 */
Jun'ichi Nomura512875b2007-12-13 14:15:25 +0000177 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 sizeof(sector_t));
179 if (!n_highs)
180 return -ENOMEM;
181
182 n_targets = (struct dm_target *) (n_highs + num);
183
184 if (n) {
185 memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
186 memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
187 }
188
189 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
190 vfree(t->highs);
191
192 t->num_allocated = num;
193 t->highs = n_highs;
194 t->targets = n_targets;
195
196 return 0;
197}
198
Al Viroaeb5d722008-09-02 15:28:45 -0400199int dm_table_create(struct dm_table **result, fmode_t mode,
Mike Anderson1134e5a2006-03-27 01:17:54 -0800200 unsigned num_targets, struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201{
Dmitry Monakhov094262d2007-10-19 22:38:51 +0100202 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204 if (!t)
205 return -ENOMEM;
206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 INIT_LIST_HEAD(&t->devices);
NeilBrown9d357b02011-01-13 20:00:01 +0000208 INIT_LIST_HEAD(&t->target_callbacks);
Mikulas Patockad5816872009-01-06 03:05:10 +0000209 atomic_set(&t->holders, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211 if (!num_targets)
212 num_targets = KEYS_PER_NODE;
213
214 num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
215
216 if (alloc_targets(t, num_targets)) {
217 kfree(t);
218 t = NULL;
219 return -ENOMEM;
220 }
221
222 t->mode = mode;
Mike Anderson1134e5a2006-03-27 01:17:54 -0800223 t->md = md;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 *result = t;
225 return 0;
226}
227
228static void free_devices(struct list_head *devices)
229{
230 struct list_head *tmp, *next;
231
Paul Jimenezafb24522008-02-08 02:09:59 +0000232 list_for_each_safe(tmp, next, devices) {
Mikulas Patocka82b15192008-10-10 13:37:09 +0100233 struct dm_dev_internal *dd =
234 list_entry(tmp, struct dm_dev_internal, list);
Jonthan Brassow1b6da752009-06-22 10:12:29 +0100235 DMWARN("dm_table_destroy: dm_put_device call missing for %s",
236 dd->dm_dev.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 kfree(dd);
238 }
239}
240
Mikulas Patockad5816872009-01-06 03:05:10 +0000241void dm_table_destroy(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
243 unsigned int i;
244
Alasdair G Kergona7940152009-12-10 23:52:23 +0000245 if (!t)
246 return;
247
Mikulas Patockad5816872009-01-06 03:05:10 +0000248 while (atomic_read(&t->holders))
249 msleep(1);
250 smp_mb();
251
Will Drewry26803b92010-08-12 04:14:03 +0100252 /* free the indexes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 if (t->depth >= 2)
254 vfree(t->index[t->depth - 2]);
255
256 /* free the targets */
257 for (i = 0; i < t->num_targets; i++) {
258 struct dm_target *tgt = t->targets + i;
259
260 if (tgt->type->dtr)
261 tgt->type->dtr(tgt);
262
263 dm_put_target_type(tgt->type);
264 }
265
266 vfree(t->highs);
267
268 /* free the device list */
Jonthan Brassow1b6da752009-06-22 10:12:29 +0100269 if (t->devices.next != &t->devices)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
Eric Sesterhenn547bc922006-03-26 18:22:50 +0200466 BUG_ON(!t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
468 if (sscanf(path, "%u:%u", &major, &minor) == 2) {
469 /* Extract the major/minor numbers */
470 dev = MKDEV(major, minor);
471 if (MAJOR(dev) != major || MINOR(dev) != minor)
472 return -EOVERFLOW;
473 } else {
474 /* convert the path to a device */
Christoph Hellwig72e82642008-08-11 00:24:08 +0200475 struct block_device *bdev = lookup_bdev(path);
476
477 if (IS_ERR(bdev))
478 return PTR_ERR(bdev);
479 dev = bdev->bd_dev;
480 bdput(bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 }
482
483 dd = find_device(&t->devices, dev);
484 if (!dd) {
485 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
486 if (!dd)
487 return -ENOMEM;
488
Mikulas Patocka82b15192008-10-10 13:37:09 +0100489 dd->dm_dev.mode = mode;
490 dd->dm_dev.bdev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800492 if ((r = open_dev(dd, dev, t->md))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 kfree(dd);
494 return r;
495 }
496
Mikulas Patocka82b15192008-10-10 13:37:09 +0100497 format_dev_t(dd->dm_dev.name, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
499 atomic_set(&dd->count, 0);
500 list_add(&dd->list, &t->devices);
501
Mikulas Patocka82b15192008-10-10 13:37:09 +0100502 } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800503 r = upgrade_mode(dd, mode, t->md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 if (r)
505 return r;
506 }
507 atomic_inc(&dd->count);
508
Mikulas Patocka82b15192008-10-10 13:37:09 +0100509 *result = &dd->dm_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 return 0;
511}
Mike Snitzer08649012011-08-02 12:32:04 +0100512EXPORT_SYMBOL(dm_get_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100514int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
Mike Snitzer5dea2712009-07-23 20:30:42 +0100515 sector_t start, sector_t len, void *data)
Bryn Reeves3cb40212006-10-03 01:15:42 -0700516{
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100517 struct queue_limits *limits = data;
518 struct block_device *bdev = dev->bdev;
Jens Axboe165125e2007-07-24 09:28:11 +0200519 struct request_queue *q = bdev_get_queue(bdev);
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +0100520 char b[BDEVNAME_SIZE];
521
522 if (unlikely(!q)) {
523 DMWARN("%s: Cannot set limits for nonexistent device %s",
524 dm_device_name(ti->table->md), bdevname(bdev, b));
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100525 return 0;
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +0100526 }
Bryn Reeves3cb40212006-10-03 01:15:42 -0700527
Martin K. Petersenb27d7f12010-01-11 03:21:50 -0500528 if (bdev_stack_limits(limits, bdev, start) < 0)
529 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
Mike Snitzera963a952009-09-04 20:40:24 +0100530 "physical_block_size=%u, logical_block_size=%u, "
531 "alignment_offset=%u, start=%llu",
532 dm_device_name(ti->table->md), bdevname(bdev, b),
533 q->limits.physical_block_size,
534 q->limits.logical_block_size,
535 q->limits.alignment_offset,
Martin K. Petersenb27d7f12010-01-11 03:21:50 -0500536 (unsigned long long) start << SECTOR_SHIFT);
Bryn Reeves3cb40212006-10-03 01:15:42 -0700537
Milan Broz9980c632008-07-21 12:00:39 +0100538 /*
539 * Check if merge fn is supported.
540 * If not we'll force DM to use PAGE_SIZE or
541 * smaller I/O, just to be safe.
Bryn Reeves3cb40212006-10-03 01:15:42 -0700542 */
Mikulas Patockad5b9dd02011-08-02 12:32:04 +0100543 if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
Mike Snitzer72d4cd92010-12-17 08:34:20 +0100544 blk_limits_max_hw_sectors(limits,
545 (unsigned int) (PAGE_SIZE >> 9));
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100546 return 0;
Bryn Reeves3cb40212006-10-03 01:15:42 -0700547}
548EXPORT_SYMBOL_GPL(dm_set_device_limits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550/*
Mike Snitzer08649012011-08-02 12:32:04 +0100551 * Decrement a device's use count and remove it if necessary.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 */
Mikulas Patocka82b15192008-10-10 13:37:09 +0100553void dm_put_device(struct dm_target *ti, struct dm_dev *d)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554{
Mikulas Patocka82b15192008-10-10 13:37:09 +0100555 struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
556 dm_dev);
557
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 if (atomic_dec_and_test(&dd->count)) {
Jun'ichi Nomuraf1659212006-03-27 01:17:59 -0800559 close_dev(dd, ti->table->md);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 list_del(&dd->list);
561 kfree(dd);
562 }
563}
Mike Snitzer08649012011-08-02 12:32:04 +0100564EXPORT_SYMBOL(dm_put_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
566/*
567 * Checks to see if the target joins onto the end of the table.
568 */
569static int adjoin(struct dm_table *table, struct dm_target *ti)
570{
571 struct dm_target *prev;
572
573 if (!table->num_targets)
574 return !ti->begin;
575
576 prev = &table->targets[table->num_targets - 1];
577 return (ti->begin == (prev->begin + prev->len));
578}
579
580/*
581 * Used to dynamically allocate the arg array.
582 */
583static char **realloc_argv(unsigned *array_size, char **old_argv)
584{
585 char **argv;
586 unsigned new_size;
587
588 new_size = *array_size ? *array_size * 2 : 64;
589 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
590 if (argv) {
591 memcpy(argv, old_argv, *array_size * sizeof(*argv));
592 *array_size = new_size;
593 }
594
595 kfree(old_argv);
596 return argv;
597}
598
599/*
600 * Destructively splits up the argument list to pass to ctr.
601 */
602int dm_split_args(int *argc, char ***argvp, char *input)
603{
604 char *start, *end = input, *out, **argv = NULL;
605 unsigned array_size = 0;
606
607 *argc = 0;
David Teigland814d6862006-06-26 00:27:31 -0700608
609 if (!input) {
610 *argvp = NULL;
611 return 0;
612 }
613
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 argv = realloc_argv(&array_size, argv);
615 if (!argv)
616 return -ENOMEM;
617
618 while (1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 /* Skip whitespace */
André Goddard Rosae7d28602009-12-14 18:01:06 -0800620 start = skip_spaces(end);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
622 if (!*start)
623 break; /* success, we hit the end */
624
625 /* 'out' is used to remove any back-quotes */
626 end = out = start;
627 while (*end) {
628 /* Everything apart from '\0' can be quoted */
629 if (*end == '\\' && *(end + 1)) {
630 *out++ = *(end + 1);
631 end += 2;
632 continue;
633 }
634
635 if (isspace(*end))
636 break; /* end of token */
637
638 *out++ = *end++;
639 }
640
641 /* have we already filled the array ? */
642 if ((*argc + 1) > array_size) {
643 argv = realloc_argv(&array_size, argv);
644 if (!argv)
645 return -ENOMEM;
646 }
647
648 /* we know this is whitespace */
649 if (*end)
650 end++;
651
652 /* terminate the string and put it in the array */
653 *out = '\0';
654 argv[*argc] = start;
655 (*argc)++;
656 }
657
658 *argvp = argv;
659 return 0;
660}
661
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100662/*
663 * Impose necessary and sufficient conditions on a devices's table such
664 * that any incoming bio which respects its logical_block_size can be
665 * processed successfully. If it falls across the boundary between
666 * two or more targets, the size of each piece it gets split into must
667 * be compatible with the logical_block_size of the target processing it.
668 */
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100669static int validate_hardware_logical_block_alignment(struct dm_table *table,
670 struct queue_limits *limits)
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100671{
672 /*
673 * This function uses arithmetic modulo the logical_block_size
674 * (in units of 512-byte sectors).
675 */
676 unsigned short device_logical_block_size_sects =
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100677 limits->logical_block_size >> SECTOR_SHIFT;
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100678
679 /*
680 * Offset of the start of the next table entry, mod logical_block_size.
681 */
682 unsigned short next_target_start = 0;
683
684 /*
685 * Given an aligned bio that extends beyond the end of a
686 * target, how many sectors must the next target handle?
687 */
688 unsigned short remaining = 0;
689
690 struct dm_target *uninitialized_var(ti);
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100691 struct queue_limits ti_limits;
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100692 unsigned i = 0;
693
694 /*
695 * Check each entry in the table in turn.
696 */
697 while (i < dm_table_get_num_targets(table)) {
698 ti = dm_table_get_target(table, i++);
699
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100700 blk_set_default_limits(&ti_limits);
701
702 /* combine all target devices' limits */
703 if (ti->type->iterate_devices)
704 ti->type->iterate_devices(ti, dm_set_device_limits,
705 &ti_limits);
706
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100707 /*
708 * If the remaining sectors fall entirely within this
709 * table entry are they compatible with its logical_block_size?
710 */
711 if (remaining < ti->len &&
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100712 remaining & ((ti_limits.logical_block_size >>
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100713 SECTOR_SHIFT) - 1))
714 break; /* Error */
715
716 next_target_start =
717 (unsigned short) ((next_target_start + ti->len) &
718 (device_logical_block_size_sects - 1));
719 remaining = next_target_start ?
720 device_logical_block_size_sects - next_target_start : 0;
721 }
722
723 if (remaining) {
724 DMWARN("%s: table line %u (start sect %llu len %llu) "
Mike Snitzera963a952009-09-04 20:40:24 +0100725 "not aligned to h/w logical block size %u",
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100726 dm_device_name(table->md), i,
727 (unsigned long long) ti->begin,
728 (unsigned long long) ti->len,
Mike Snitzer754c5fc2009-06-22 10:12:34 +0100729 limits->logical_block_size);
Mike Snitzerbe6d4302009-06-22 10:12:31 +0100730 return -EINVAL;
731 }
732
733 return 0;
734}
735
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736int dm_table_add_target(struct dm_table *t, const char *type,
737 sector_t start, sector_t len, char *params)
738{
739 int r = -EINVAL, argc;
740 char **argv;
741 struct dm_target *tgt;
742
743 if ((r = check_space(t)))
744 return r;
745
746 tgt = t->targets + t->num_targets;
747 memset(tgt, 0, sizeof(*tgt));
748
749 if (!len) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700750 DMERR("%s: zero-length target", dm_device_name(t->md));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 return -EINVAL;
752 }
753
754 tgt->type = dm_get_target_type(type);
755 if (!tgt->type) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700756 DMERR("%s: %s: unknown target type", dm_device_name(t->md),
757 type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 return -EINVAL;
759 }
760
761 tgt->table = t;
762 tgt->begin = start;
763 tgt->len = len;
764 tgt->error = "Unknown error";
765
766 /*
767 * Does this target adjoin the previous one ?
768 */
769 if (!adjoin(t, tgt)) {
770 tgt->error = "Gap in table";
771 r = -EINVAL;
772 goto bad;
773 }
774
775 r = dm_split_args(&argc, &argv, params);
776 if (r) {
777 tgt->error = "couldn't split parameters (insufficient memory)";
778 goto bad;
779 }
780
781 r = tgt->type->ctr(tgt, argc, argv);
782 kfree(argv);
783 if (r)
784 goto bad;
785
786 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
787
Mike Snitzer936688d2011-08-02 12:32:01 +0100788 if (!tgt->num_discard_requests && tgt->discards_supported)
789 DMWARN("%s: %s: ignoring discards_supported because num_discard_requests is zero.",
790 dm_device_name(t->md), type);
Mike Snitzer5ae89a82010-08-12 04:14:08 +0100791
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 return 0;
793
794 bad:
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700795 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 dm_put_target_type(tgt->type);
797 return r;
798}
799
Mike Snitzer498f0102011-08-02 12:32:04 +0100800/*
801 * Target argument parsing helpers.
802 */
803static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
804 unsigned *value, char **error, unsigned grouped)
805{
806 const char *arg_str = dm_shift_arg(arg_set);
807
808 if (!arg_str ||
809 (sscanf(arg_str, "%u", value) != 1) ||
810 (*value < arg->min) ||
811 (*value > arg->max) ||
812 (grouped && arg_set->argc < *value)) {
813 *error = arg->error;
814 return -EINVAL;
815 }
816
817 return 0;
818}
819
820int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
821 unsigned *value, char **error)
822{
823 return validate_next_arg(arg, arg_set, value, error, 0);
824}
825EXPORT_SYMBOL(dm_read_arg);
826
827int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
828 unsigned *value, char **error)
829{
830 return validate_next_arg(arg, arg_set, value, error, 1);
831}
832EXPORT_SYMBOL(dm_read_arg_group);
833
834const char *dm_shift_arg(struct dm_arg_set *as)
835{
836 char *r;
837
838 if (as->argc) {
839 as->argc--;
840 r = *as->argv;
841 as->argv++;
842 return r;
843 }
844
845 return NULL;
846}
847EXPORT_SYMBOL(dm_shift_arg);
848
849void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
850{
851 BUG_ON(as->argc < num_args);
852 as->argc -= num_args;
853 as->argv += num_args;
854}
855EXPORT_SYMBOL(dm_consume_args);
856
Will Drewry26803b92010-08-12 04:14:03 +0100857static int dm_table_set_type(struct dm_table *t)
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100858{
859 unsigned i;
860 unsigned bio_based = 0, request_based = 0;
861 struct dm_target *tgt;
862 struct dm_dev_internal *dd;
863 struct list_head *devices;
864
865 for (i = 0; i < t->num_targets; i++) {
866 tgt = t->targets + i;
867 if (dm_target_request_based(tgt))
868 request_based = 1;
869 else
870 bio_based = 1;
871
872 if (bio_based && request_based) {
873 DMWARN("Inconsistent table: different target types"
874 " can't be mixed up");
875 return -EINVAL;
876 }
877 }
878
879 if (bio_based) {
880 /* We must use this table as bio-based */
881 t->type = DM_TYPE_BIO_BASED;
882 return 0;
883 }
884
885 BUG_ON(!request_based); /* No targets in this table */
886
887 /* Non-request-stackable devices can't be used for request-based dm */
888 devices = dm_table_get_devices(t);
889 list_for_each_entry(dd, devices, list) {
890 if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
891 DMWARN("table load rejected: including"
892 " non-request-stackable devices");
893 return -EINVAL;
894 }
895 }
896
897 /*
898 * Request-based dm supports only tables that have a single target now.
899 * To support multiple targets, request splitting support is needed,
900 * and that needs lots of changes in the block-layer.
901 * (e.g. request completion process for partial completion.)
902 */
903 if (t->num_targets > 1) {
904 DMWARN("Request-based dm doesn't support multiple targets yet");
905 return -EINVAL;
906 }
907
908 t->type = DM_TYPE_REQUEST_BASED;
909
910 return 0;
911}
912
913unsigned dm_table_get_type(struct dm_table *t)
914{
915 return t->type;
916}
917
918bool dm_table_request_based(struct dm_table *t)
919{
920 return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
921}
922
923int dm_table_alloc_md_mempools(struct dm_table *t)
924{
925 unsigned type = dm_table_get_type(t);
926
927 if (unlikely(type == DM_TYPE_NONE)) {
928 DMWARN("no table type is set, can't allocate mempools");
929 return -EINVAL;
930 }
931
Martin K. Petersena91a2782011-03-17 11:11:05 +0100932 t->mempools = dm_alloc_md_mempools(type, t->integrity_supported);
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100933 if (!t->mempools)
934 return -ENOMEM;
935
936 return 0;
937}
938
939void dm_table_free_md_mempools(struct dm_table *t)
940{
941 dm_free_md_mempools(t->mempools);
942 t->mempools = NULL;
943}
944
945struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
946{
947 return t->mempools;
948}
949
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950static int setup_indexes(struct dm_table *t)
951{
952 int i;
953 unsigned int total = 0;
954 sector_t *indexes;
955
956 /* allocate the space for *all* the indexes */
957 for (i = t->depth - 2; i >= 0; i--) {
958 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
959 total += t->counts[i];
960 }
961
962 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
963 if (!indexes)
964 return -ENOMEM;
965
966 /* set up internal nodes, bottom-up */
Jun'ichi Nomura82d601d2008-02-08 02:10:04 +0000967 for (i = t->depth - 2; i >= 0; i--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 t->index[i] = indexes;
969 indexes += (KEYS_PER_NODE * t->counts[i]);
970 setup_btree_index(i, t);
971 }
972
973 return 0;
974}
975
976/*
977 * Builds the btree to index the map.
978 */
Will Drewry26803b92010-08-12 04:14:03 +0100979static int dm_table_build_index(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980{
981 int r = 0;
982 unsigned int leaf_nodes;
983
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 /* how many indexes will the btree have ? */
985 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
986 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
987
988 /* leaf layer has already been set up */
989 t->counts[t->depth - 1] = leaf_nodes;
990 t->index[t->depth - 1] = t->highs;
991
992 if (t->depth >= 2)
993 r = setup_indexes(t);
994
995 return r;
996}
997
Will Drewry26803b92010-08-12 04:14:03 +0100998/*
Mike Snitzera63a5cf2011-04-01 21:02:31 +0200999 * Get a disk whose integrity profile reflects the table's profile.
1000 * If %match_all is true, all devices' profiles must match.
1001 * If %match_all is false, all devices must at least have an
1002 * allocated integrity profile; but uninitialized is ok.
1003 * Returns NULL if integrity support was inconsistent or unavailable.
1004 */
1005static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1006 bool match_all)
1007{
1008 struct list_head *devices = dm_table_get_devices(t);
1009 struct dm_dev_internal *dd = NULL;
1010 struct gendisk *prev_disk = NULL, *template_disk = NULL;
1011
1012 list_for_each_entry(dd, devices, list) {
1013 template_disk = dd->dm_dev.bdev->bd_disk;
1014 if (!blk_get_integrity(template_disk))
1015 goto no_integrity;
1016 if (!match_all && !blk_integrity_is_initialized(template_disk))
1017 continue; /* skip uninitialized profiles */
1018 else if (prev_disk &&
1019 blk_integrity_compare(prev_disk, template_disk) < 0)
1020 goto no_integrity;
1021 prev_disk = template_disk;
1022 }
1023
1024 return template_disk;
1025
1026no_integrity:
1027 if (prev_disk)
1028 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1029 dm_device_name(t->md),
1030 prev_disk->disk_name,
1031 template_disk->disk_name);
1032 return NULL;
1033}
1034
1035/*
Will Drewry26803b92010-08-12 04:14:03 +01001036 * Register the mapped device for blk_integrity support if
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001037 * the underlying devices have an integrity profile. But all devices
1038 * may not have matching profiles (checking all devices isn't reliable
1039 * during table load because this table may use other DM device(s) which
1040 * must be resumed before they will have an initialized integity profile).
1041 * Stacked DM devices force a 2 stage integrity profile validation:
1042 * 1 - during load, validate all initialized integrity profiles match
1043 * 2 - during resume, validate all integrity profiles match
Will Drewry26803b92010-08-12 04:14:03 +01001044 */
1045static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1046{
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001047 struct gendisk *template_disk = NULL;
Will Drewry26803b92010-08-12 04:14:03 +01001048
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001049 template_disk = dm_table_get_integrity_disk(t, false);
1050 if (!template_disk)
1051 return 0;
Will Drewry26803b92010-08-12 04:14:03 +01001052
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001053 if (!blk_integrity_is_initialized(dm_disk(md))) {
1054 t->integrity_supported = 1;
1055 return blk_integrity_register(dm_disk(md), NULL);
1056 }
1057
1058 /*
1059 * If DM device already has an initalized integrity
1060 * profile the new profile should not conflict.
1061 */
1062 if (blk_integrity_is_initialized(template_disk) &&
1063 blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1064 DMWARN("%s: conflict with existing integrity profile: "
1065 "%s profile mismatch",
1066 dm_device_name(t->md),
1067 template_disk->disk_name);
1068 return 1;
1069 }
1070
1071 /* Preserve existing initialized integrity profile */
1072 t->integrity_supported = 1;
Will Drewry26803b92010-08-12 04:14:03 +01001073 return 0;
1074}
1075
1076/*
1077 * Prepares the table for use by building the indices,
1078 * setting the type, and allocating mempools.
1079 */
1080int dm_table_complete(struct dm_table *t)
1081{
1082 int r;
1083
1084 r = dm_table_set_type(t);
1085 if (r) {
1086 DMERR("unable to set table type");
1087 return r;
1088 }
1089
1090 r = dm_table_build_index(t);
1091 if (r) {
1092 DMERR("unable to build btrees");
1093 return r;
1094 }
1095
1096 r = dm_table_prealloc_integrity(t, t->md);
1097 if (r) {
1098 DMERR("could not register integrity profile.");
1099 return r;
1100 }
1101
1102 r = dm_table_alloc_md_mempools(t);
1103 if (r)
1104 DMERR("unable to allocate mempools");
1105
1106 return r;
1107}
1108
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001109static DEFINE_MUTEX(_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110void dm_table_event_callback(struct dm_table *t,
1111 void (*fn)(void *), void *context)
1112{
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001113 mutex_lock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114 t->event_fn = fn;
1115 t->event_context = context;
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001116 mutex_unlock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117}
1118
1119void dm_table_event(struct dm_table *t)
1120{
1121 /*
1122 * You can no longer call dm_table_event() from interrupt
1123 * context, use a bottom half instead.
1124 */
1125 BUG_ON(in_interrupt());
1126
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001127 mutex_lock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 if (t->event_fn)
1129 t->event_fn(t->event_context);
Arjan van de Ven48c9c272006-03-27 01:18:20 -08001130 mutex_unlock(&_event_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131}
Mike Snitzer08649012011-08-02 12:32:04 +01001132EXPORT_SYMBOL(dm_table_event);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133
1134sector_t dm_table_get_size(struct dm_table *t)
1135{
1136 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1137}
Mike Snitzer08649012011-08-02 12:32:04 +01001138EXPORT_SYMBOL(dm_table_get_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139
1140struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1141{
Milan Broz14353532006-06-26 00:27:27 -07001142 if (index >= t->num_targets)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 return NULL;
1144
1145 return t->targets + index;
1146}
1147
1148/*
1149 * Search the btree for the correct target.
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001150 *
1151 * Caller should check returned pointer with dm_target_is_valid()
1152 * to trap I/O beyond end of device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 */
1154struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1155{
1156 unsigned int l, n = 0, k = 0;
1157 sector_t *node;
1158
1159 for (l = 0; l < t->depth; l++) {
1160 n = get_child(n, k);
1161 node = get_node(t, l, n);
1162
1163 for (k = 0; k < KEYS_PER_NODE; k++)
1164 if (node[k] >= sector)
1165 break;
1166 }
1167
1168 return &t->targets[(KEYS_PER_NODE * n) + k];
1169}
1170
Martin K. Petersen9c470082009-04-09 00:27:12 +01001171/*
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001172 * Establish the new table's queue_limits and validate them.
1173 */
1174int dm_calculate_queue_limits(struct dm_table *table,
1175 struct queue_limits *limits)
1176{
1177 struct dm_target *uninitialized_var(ti);
1178 struct queue_limits ti_limits;
1179 unsigned i = 0;
1180
1181 blk_set_default_limits(limits);
1182
1183 while (i < dm_table_get_num_targets(table)) {
1184 blk_set_default_limits(&ti_limits);
1185
1186 ti = dm_table_get_target(table, i++);
1187
1188 if (!ti->type->iterate_devices)
1189 goto combine_limits;
1190
1191 /*
1192 * Combine queue limits of all the devices this target uses.
1193 */
1194 ti->type->iterate_devices(ti, dm_set_device_limits,
1195 &ti_limits);
1196
Mike Snitzer40bea432009-09-04 20:40:25 +01001197 /* Set I/O hints portion of queue limits */
1198 if (ti->type->io_hints)
1199 ti->type->io_hints(ti, &ti_limits);
1200
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001201 /*
1202 * Check each device area is consistent with the target's
1203 * overall queue limits.
1204 */
Mikulas Patockaf6a1ed12009-09-04 20:40:22 +01001205 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1206 &ti_limits))
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001207 return -EINVAL;
1208
1209combine_limits:
1210 /*
1211 * Merge this target's queue limits into the overall limits
1212 * for the table.
1213 */
1214 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
Martin K. Petersenb27d7f12010-01-11 03:21:50 -05001215 DMWARN("%s: adding target device "
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001216 "(start sect %llu len %llu) "
Martin K. Petersenb27d7f12010-01-11 03:21:50 -05001217 "caused an alignment inconsistency",
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001218 dm_device_name(table->md),
1219 (unsigned long long) ti->begin,
1220 (unsigned long long) ti->len);
1221 }
1222
1223 return validate_hardware_logical_block_alignment(table, limits);
1224}
1225
1226/*
Martin K. Petersen9c470082009-04-09 00:27:12 +01001227 * Set the integrity profile for this device if all devices used have
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001228 * matching profiles. We're quite deep in the resume path but still
1229 * don't know if all devices (particularly DM devices this device
1230 * may be stacked on) have matching profiles. Even if the profiles
1231 * don't match we have no way to fail (to resume) at this point.
Martin K. Petersen9c470082009-04-09 00:27:12 +01001232 */
1233static void dm_table_set_integrity(struct dm_table *t)
1234{
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001235 struct gendisk *template_disk = NULL;
Martin K. Petersen9c470082009-04-09 00:27:12 +01001236
1237 if (!blk_get_integrity(dm_disk(t->md)))
1238 return;
1239
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001240 template_disk = dm_table_get_integrity_disk(t, true);
1241 if (!template_disk &&
1242 blk_integrity_is_initialized(dm_disk(t->md))) {
1243 DMWARN("%s: device no longer has a valid integrity profile",
1244 dm_device_name(t->md));
1245 return;
Martin K. Petersen9c470082009-04-09 00:27:12 +01001246 }
Martin K. Petersen9c470082009-04-09 00:27:12 +01001247 blk_integrity_register(dm_disk(t->md),
Mike Snitzera63a5cf2011-04-01 21:02:31 +02001248 blk_get_integrity(template_disk));
Martin K. Petersen9c470082009-04-09 00:27:12 +01001249}
1250
Mike Snitzered8b7522011-08-02 12:32:08 +01001251static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1252 sector_t start, sector_t len, void *data)
1253{
1254 unsigned flush = (*(unsigned *)data);
1255 struct request_queue *q = bdev_get_queue(dev->bdev);
1256
1257 return q && (q->flush_flags & flush);
1258}
1259
1260static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1261{
1262 struct dm_target *ti;
1263 unsigned i = 0;
1264
1265 /*
1266 * Require at least one underlying device to support flushes.
1267 * t->devices includes internal dm devices such as mirror logs
1268 * so we need to use iterate_devices here, which targets
1269 * supporting flushes must provide.
1270 */
1271 while (i < dm_table_get_num_targets(t)) {
1272 ti = dm_table_get_target(t, i++);
1273
1274 if (!ti->num_flush_requests)
1275 continue;
1276
1277 if (ti->type->iterate_devices &&
1278 ti->type->iterate_devices(ti, device_flush_capable, &flush))
1279 return 1;
1280 }
1281
1282 return 0;
1283}
1284
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001285void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1286 struct queue_limits *limits)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287{
Mike Snitzered8b7522011-08-02 12:32:08 +01001288 unsigned flush = 0;
1289
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290 /*
Mike Snitzer11977642009-06-22 10:12:32 +01001291 * Copy table's limits to the DM device's request_queue
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 */
Mike Snitzer754c5fc2009-06-22 10:12:34 +01001293 q->limits = *limits;
Jens Axboec9a3f6d2008-04-29 19:12:35 +02001294
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001295 if (!dm_table_supports_discards(t))
1296 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1297 else
1298 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1299
Mike Snitzered8b7522011-08-02 12:32:08 +01001300 if (dm_table_supports_flush(t, REQ_FLUSH)) {
1301 flush |= REQ_FLUSH;
1302 if (dm_table_supports_flush(t, REQ_FUA))
1303 flush |= REQ_FUA;
1304 }
1305 blk_queue_flush(q, flush);
1306
Martin K. Petersen9c470082009-04-09 00:27:12 +01001307 dm_table_set_integrity(t);
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001308
1309 /*
1310 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1311 * visible to other CPUs because, once the flag is set, incoming bios
1312 * are processed by request-based dm, which refers to the queue
1313 * settings.
1314 * Until the flag set, bios are passed to bio-based dm and queued to
1315 * md->deferred where queue settings are not needed yet.
1316 * Those bios are passed to request-based dm at the resume time.
1317 */
1318 smp_mb();
1319 if (dm_table_request_based(t))
1320 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321}
1322
1323unsigned int dm_table_get_num_targets(struct dm_table *t)
1324{
1325 return t->num_targets;
1326}
1327
1328struct list_head *dm_table_get_devices(struct dm_table *t)
1329{
1330 return &t->devices;
1331}
1332
Al Viroaeb5d722008-09-02 15:28:45 -04001333fmode_t dm_table_get_mode(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334{
1335 return t->mode;
1336}
Mike Snitzer08649012011-08-02 12:32:04 +01001337EXPORT_SYMBOL(dm_table_get_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338
1339static void suspend_targets(struct dm_table *t, unsigned postsuspend)
1340{
1341 int i = t->num_targets;
1342 struct dm_target *ti = t->targets;
1343
1344 while (i--) {
1345 if (postsuspend) {
1346 if (ti->type->postsuspend)
1347 ti->type->postsuspend(ti);
1348 } else if (ti->type->presuspend)
1349 ti->type->presuspend(ti);
1350
1351 ti++;
1352 }
1353}
1354
1355void dm_table_presuspend_targets(struct dm_table *t)
1356{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07001357 if (!t)
1358 return;
1359
Adrian Bunke8488d02008-04-24 22:10:51 +01001360 suspend_targets(t, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361}
1362
1363void dm_table_postsuspend_targets(struct dm_table *t)
1364{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07001365 if (!t)
1366 return;
1367
Adrian Bunke8488d02008-04-24 22:10:51 +01001368 suspend_targets(t, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369}
1370
Milan Broz8757b772006-10-03 01:15:36 -07001371int dm_table_resume_targets(struct dm_table *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372{
Milan Broz8757b772006-10-03 01:15:36 -07001373 int i, r = 0;
1374
1375 for (i = 0; i < t->num_targets; i++) {
1376 struct dm_target *ti = t->targets + i;
1377
1378 if (!ti->type->preresume)
1379 continue;
1380
1381 r = ti->type->preresume(ti);
1382 if (r)
1383 return r;
1384 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385
1386 for (i = 0; i < t->num_targets; i++) {
1387 struct dm_target *ti = t->targets + i;
1388
1389 if (ti->type->resume)
1390 ti->type->resume(ti);
1391 }
Milan Broz8757b772006-10-03 01:15:36 -07001392
1393 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394}
1395
NeilBrown9d357b02011-01-13 20:00:01 +00001396void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1397{
1398 list_add(&cb->list, &t->target_callbacks);
1399}
1400EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1401
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1403{
Mikulas Patocka82b15192008-10-10 13:37:09 +01001404 struct dm_dev_internal *dd;
Paul Jimenezafb24522008-02-08 02:09:59 +00001405 struct list_head *devices = dm_table_get_devices(t);
NeilBrown9d357b02011-01-13 20:00:01 +00001406 struct dm_target_callbacks *cb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 int r = 0;
1408
Paul Jimenezafb24522008-02-08 02:09:59 +00001409 list_for_each_entry(dd, devices, list) {
Mikulas Patocka82b15192008-10-10 13:37:09 +01001410 struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
Alasdair G Kergon0c2322e2008-10-10 13:37:13 +01001411 char b[BDEVNAME_SIZE];
1412
1413 if (likely(q))
1414 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1415 else
1416 DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1417 dm_device_name(t->md),
1418 bdevname(dd->dm_dev.bdev, b));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419 }
1420
NeilBrown9d357b02011-01-13 20:00:01 +00001421 list_for_each_entry(cb, &t->target_callbacks, list)
1422 if (cb->congested_fn)
1423 r |= cb->congested_fn(cb, bdi_bits);
1424
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425 return r;
1426}
1427
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001428int dm_table_any_busy_target(struct dm_table *t)
1429{
1430 unsigned i;
1431 struct dm_target *ti;
1432
1433 for (i = 0; i < t->num_targets; i++) {
1434 ti = t->targets + i;
1435 if (ti->type->busy && ti->type->busy(ti))
1436 return 1;
1437 }
1438
1439 return 0;
1440}
1441
Mike Anderson1134e5a2006-03-27 01:17:54 -08001442struct mapped_device *dm_table_get_md(struct dm_table *t)
1443{
Mike Anderson1134e5a2006-03-27 01:17:54 -08001444 return t->md;
1445}
Mike Snitzer08649012011-08-02 12:32:04 +01001446EXPORT_SYMBOL(dm_table_get_md);
Mike Anderson1134e5a2006-03-27 01:17:54 -08001447
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001448static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1449 sector_t start, sector_t len, void *data)
1450{
1451 struct request_queue *q = bdev_get_queue(dev->bdev);
1452
1453 return q && blk_queue_discard(q);
1454}
1455
1456bool dm_table_supports_discards(struct dm_table *t)
1457{
1458 struct dm_target *ti;
1459 unsigned i = 0;
1460
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001461 /*
Mike Snitzer4c259322011-05-29 12:52:55 +01001462 * Unless any target used by the table set discards_supported,
1463 * require at least one underlying device to support discards.
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001464 * t->devices includes internal dm devices such as mirror logs
1465 * so we need to use iterate_devices here, which targets
Mike Snitzer936688d2011-08-02 12:32:01 +01001466 * supporting discard selectively must provide.
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001467 */
1468 while (i < dm_table_get_num_targets(t)) {
1469 ti = dm_table_get_target(t, i++);
1470
Mike Snitzer936688d2011-08-02 12:32:01 +01001471 if (!ti->num_discard_requests)
1472 continue;
1473
Mike Snitzer4c259322011-05-29 12:52:55 +01001474 if (ti->discards_supported)
1475 return 1;
1476
Mike Snitzer5ae89a82010-08-12 04:14:08 +01001477 if (ti->type->iterate_devices &&
1478 ti->type->iterate_devices(ti, device_discard_capable, NULL))
1479 return 1;
1480 }
1481
1482 return 0;
1483}