blob: 3167480b532cd92e64c12831bb3ac4d424f37270 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
Milan Broz784aae72009-01-06 03:05:12 +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"
Mike Anderson51e5b2b2007-10-19 22:48:00 +01009#include "dm-uevent.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070010
11#include <linux/init.h>
12#include <linux/module.h>
Arjan van de Ven48c9c272006-03-27 01:18:20 -080013#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/moduleparam.h>
15#include <linux/blkpg.h>
16#include <linux/bio.h>
17#include <linux/buffer_head.h>
18#include <linux/mempool.h>
19#include <linux/slab.h>
20#include <linux/idr.h>
Darrick J. Wong3ac51e72006-03-27 01:17:54 -080021#include <linux/hdreg.h>
Li Zefan55782132009-06-09 13:43:05 +080022
23#include <trace/events/block.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Alasdair G Kergon72d94862006-06-26 00:27:35 -070025#define DM_MSG_PREFIX "core"
26
Milan Broz60935eb2009-06-22 10:12:30 +010027/*
28 * Cookies are numeric values sent with CHANGE and REMOVE
29 * uevents while resuming, removing or renaming the device.
30 */
31#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
32#define DM_COOKIE_LENGTH 24
33
Linus Torvalds1da177e2005-04-16 15:20:36 -070034static const char *_name = DM_NAME;
35
36static unsigned int major = 0;
37static unsigned int _major = 0;
38
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -070039static DEFINE_SPINLOCK(_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040/*
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +000041 * For bio-based dm.
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 * One of these is allocated per bio.
43 */
44struct dm_io {
45 struct mapped_device *md;
46 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 atomic_t io_count;
Richard Kennedy6ae2fa62008-07-21 12:00:28 +010048 struct bio *bio;
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -080049 unsigned long start_time;
Kiyoshi Uedaf88fb982009-10-16 23:18:15 +010050 spinlock_t endio_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -070051};
52
53/*
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +000054 * For bio-based dm.
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 * One of these is allocated per target within a bio. Hopefully
56 * this will be simplified out one day.
57 */
Alasdair G Kergon028867a2007-07-12 17:26:32 +010058struct dm_target_io {
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 struct dm_io *io;
60 struct dm_target *ti;
61 union map_info info;
62};
63
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +000064/*
65 * For request-based dm.
66 * One of these is allocated per request.
67 */
68struct dm_rq_target_io {
69 struct mapped_device *md;
70 struct dm_target *ti;
71 struct request *orig, clone;
72 int error;
73 union map_info info;
74};
75
76/*
77 * For request-based dm.
78 * One of these is allocated per bio.
79 */
80struct dm_rq_clone_bio_info {
81 struct bio *orig;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +010082 struct dm_rq_target_io *tio;
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +000083};
84
Linus Torvalds1da177e2005-04-16 15:20:36 -070085union map_info *dm_get_mapinfo(struct bio *bio)
86{
Alasdair G Kergon17b2f662006-06-26 00:27:33 -070087 if (bio && bio->bi_private)
Alasdair G Kergon028867a2007-07-12 17:26:32 +010088 return &((struct dm_target_io *)bio->bi_private)->info;
Alasdair G Kergon17b2f662006-06-26 00:27:33 -070089 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090}
91
Kiyoshi Uedacec47e32009-06-22 10:12:35 +010092union map_info *dm_get_rq_mapinfo(struct request *rq)
93{
94 if (rq && rq->end_io_data)
95 return &((struct dm_rq_target_io *)rq->end_io_data)->info;
96 return NULL;
97}
98EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
99
Jeff Mahoneyba61fdd2006-06-26 00:27:21 -0700100#define MINOR_ALLOCED ((void *)-1)
101
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102/*
103 * Bits for the md->flags field.
104 */
Alasdair G Kergon1eb787e2009-04-09 00:27:14 +0100105#define DMF_BLOCK_IO_FOR_SUSPEND 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106#define DMF_SUSPENDED 1
Alasdair G Kergonaa8d7c22006-01-06 00:20:06 -0800107#define DMF_FROZEN 2
Jeff Mahoneyfba9f902006-06-26 00:27:23 -0700108#define DMF_FREEING 3
Alasdair G Kergon5c6bd752006-06-26 00:27:34 -0700109#define DMF_DELETING 4
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800110#define DMF_NOFLUSH_SUSPENDING 5
Alasdair G Kergon1eb787e2009-04-09 00:27:14 +0100111#define DMF_QUEUE_IO_TO_THREAD 6
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
Milan Broz304f3f62008-02-08 02:11:17 +0000113/*
114 * Work processed by per-device workqueue.
115 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116struct mapped_device {
Alasdair G Kergon2ca33102005-07-28 21:16:00 -0700117 struct rw_semaphore io_lock;
Daniel Walkere61290a2008-02-08 02:10:08 +0000118 struct mutex suspend_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 rwlock_t map_lock;
120 atomic_t holders;
Alasdair G Kergon5c6bd752006-06-26 00:27:34 -0700121 atomic_t open_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
123 unsigned long flags;
124
Jens Axboe165125e2007-07-24 09:28:11 +0200125 struct request_queue *queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 struct gendisk *disk;
Mike Anderson7e51f252006-03-27 01:17:52 -0800127 char name[16];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
129 void *interface_ptr;
130
131 /*
132 * A list of ios that arrived while we were suspended.
133 */
Nikanth Karthikesan316d3152009-10-06 20:16:55 +0200134 atomic_t pending[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 wait_queue_head_t wait;
Mikulas Patocka53d59142009-04-02 19:55:37 +0100136 struct work_struct work;
Kiyoshi Ueda74859362006-12-08 02:41:02 -0800137 struct bio_list deferred;
Mikulas Patocka022c2612009-04-02 19:55:39 +0100138 spinlock_t deferred_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140 /*
Mikulas Patockaaf7e4662009-04-09 00:27:16 +0100141 * An error from the barrier request currently being processed.
142 */
143 int barrier_error;
144
145 /*
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000146 * Protect barrier_error from concurrent endio processing
147 * in request-based dm.
148 */
149 spinlock_t barrier_error_lock;
150
151 /*
Milan Broz304f3f62008-02-08 02:11:17 +0000152 * Processing queue (flush/barriers)
153 */
154 struct workqueue_struct *wq;
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000155 struct work_struct barrier_work;
156
157 /* A pointer to the currently processing pre/post flush request */
158 struct request *flush_request;
Milan Broz304f3f62008-02-08 02:11:17 +0000159
160 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 * The current mapping.
162 */
163 struct dm_table *map;
164
165 /*
166 * io objects are allocated from here.
167 */
168 mempool_t *io_pool;
169 mempool_t *tio_pool;
170
Stefan Bader9faf4002006-10-03 01:15:41 -0700171 struct bio_set *bs;
172
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 /*
174 * Event handling.
175 */
176 atomic_t event_nr;
177 wait_queue_head_t eventq;
Mike Anderson7a8c3d32007-10-19 22:48:01 +0100178 atomic_t uevent_seq;
179 struct list_head uevent_list;
180 spinlock_t uevent_lock; /* Protect access to uevent_list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182 /*
183 * freeze/thaw support require holding onto a super block
184 */
185 struct super_block *frozen_sb;
Mikulas Patockadb8fef42009-06-22 10:12:15 +0100186 struct block_device *bdev;
Darrick J. Wong3ac51e72006-03-27 01:17:54 -0800187
188 /* forced geometry settings */
189 struct hd_geometry geometry;
Milan Broz784aae72009-01-06 03:05:12 +0000190
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100191 /* For saving the address of __make_request for request based dm */
192 make_request_fn *saved_make_request_fn;
193
Milan Broz784aae72009-01-06 03:05:12 +0000194 /* sysfs handle */
195 struct kobject kobj;
Mikulas Patocka52b1fd52009-06-22 10:12:21 +0100196
197 /* zero-length barrier that will be cloned and submitted to targets */
198 struct bio barrier_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199};
200
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +0100201/*
202 * For mempools pre-allocation at the table loading time.
203 */
204struct dm_md_mempools {
205 mempool_t *io_pool;
206 mempool_t *tio_pool;
207 struct bio_set *bs;
208};
209
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210#define MIN_IOS 256
Christoph Lametere18b8902006-12-06 20:33:20 -0800211static struct kmem_cache *_io_cache;
212static struct kmem_cache *_tio_cache;
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +0000213static struct kmem_cache *_rq_tio_cache;
214static struct kmem_cache *_rq_bio_info_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216static int __init local_init(void)
217{
Kiyoshi Ueda51157b42008-10-21 17:45:08 +0100218 int r = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 /* allocate a slab for the dm_ios */
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100221 _io_cache = KMEM_CACHE(dm_io, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 if (!_io_cache)
Kiyoshi Ueda51157b42008-10-21 17:45:08 +0100223 return r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
225 /* allocate a slab for the target ios */
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100226 _tio_cache = KMEM_CACHE(dm_target_io, 0);
Kiyoshi Ueda51157b42008-10-21 17:45:08 +0100227 if (!_tio_cache)
228 goto out_free_io_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +0000230 _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
231 if (!_rq_tio_cache)
232 goto out_free_tio_cache;
233
234 _rq_bio_info_cache = KMEM_CACHE(dm_rq_clone_bio_info, 0);
235 if (!_rq_bio_info_cache)
236 goto out_free_rq_tio_cache;
237
Mike Anderson51e5b2b2007-10-19 22:48:00 +0100238 r = dm_uevent_init();
Kiyoshi Ueda51157b42008-10-21 17:45:08 +0100239 if (r)
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +0000240 goto out_free_rq_bio_info_cache;
Mike Anderson51e5b2b2007-10-19 22:48:00 +0100241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 _major = major;
243 r = register_blkdev(_major, _name);
Kiyoshi Ueda51157b42008-10-21 17:45:08 +0100244 if (r < 0)
245 goto out_uevent_exit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247 if (!_major)
248 _major = r;
249
250 return 0;
Kiyoshi Ueda51157b42008-10-21 17:45:08 +0100251
252out_uevent_exit:
253 dm_uevent_exit();
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +0000254out_free_rq_bio_info_cache:
255 kmem_cache_destroy(_rq_bio_info_cache);
256out_free_rq_tio_cache:
257 kmem_cache_destroy(_rq_tio_cache);
Kiyoshi Ueda51157b42008-10-21 17:45:08 +0100258out_free_tio_cache:
259 kmem_cache_destroy(_tio_cache);
260out_free_io_cache:
261 kmem_cache_destroy(_io_cache);
262
263 return r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264}
265
266static void local_exit(void)
267{
Kiyoshi Ueda8fbf26a2009-01-06 03:05:06 +0000268 kmem_cache_destroy(_rq_bio_info_cache);
269 kmem_cache_destroy(_rq_tio_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 kmem_cache_destroy(_tio_cache);
271 kmem_cache_destroy(_io_cache);
Akinobu Mita00d59402007-07-17 04:03:46 -0700272 unregister_blkdev(_major, _name);
Mike Anderson51e5b2b2007-10-19 22:48:00 +0100273 dm_uevent_exit();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275 _major = 0;
276
277 DMINFO("cleaned up");
278}
279
Alasdair G Kergonb9249e52008-02-08 02:09:51 +0000280static int (*_inits[])(void) __initdata = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 local_init,
282 dm_target_init,
283 dm_linear_init,
284 dm_stripe_init,
Mikulas Patocka952b3552009-12-10 23:51:57 +0000285 dm_io_init,
Mikulas Patocka945fa4d2008-04-24 21:43:49 +0100286 dm_kcopyd_init,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 dm_interface_init,
288};
289
Alasdair G Kergonb9249e52008-02-08 02:09:51 +0000290static void (*_exits[])(void) = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 local_exit,
292 dm_target_exit,
293 dm_linear_exit,
294 dm_stripe_exit,
Mikulas Patocka952b3552009-12-10 23:51:57 +0000295 dm_io_exit,
Mikulas Patocka945fa4d2008-04-24 21:43:49 +0100296 dm_kcopyd_exit,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 dm_interface_exit,
298};
299
300static int __init dm_init(void)
301{
302 const int count = ARRAY_SIZE(_inits);
303
304 int r, i;
305
306 for (i = 0; i < count; i++) {
307 r = _inits[i]();
308 if (r)
309 goto bad;
310 }
311
312 return 0;
313
314 bad:
315 while (i--)
316 _exits[i]();
317
318 return r;
319}
320
321static void __exit dm_exit(void)
322{
323 int i = ARRAY_SIZE(_exits);
324
325 while (i--)
326 _exits[i]();
327}
328
329/*
330 * Block device functions
331 */
Mike Anderson432a2122009-12-10 23:52:20 +0000332int dm_deleting_md(struct mapped_device *md)
333{
334 return test_bit(DMF_DELETING, &md->flags);
335}
336
Al Virofe5f9f22008-03-02 10:29:31 -0500337static int dm_blk_open(struct block_device *bdev, fmode_t mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338{
339 struct mapped_device *md;
340
Jeff Mahoneyfba9f902006-06-26 00:27:23 -0700341 spin_lock(&_minor_lock);
342
Al Virofe5f9f22008-03-02 10:29:31 -0500343 md = bdev->bd_disk->private_data;
Jeff Mahoneyfba9f902006-06-26 00:27:23 -0700344 if (!md)
345 goto out;
346
Alasdair G Kergon5c6bd752006-06-26 00:27:34 -0700347 if (test_bit(DMF_FREEING, &md->flags) ||
Mike Anderson432a2122009-12-10 23:52:20 +0000348 dm_deleting_md(md)) {
Jeff Mahoneyfba9f902006-06-26 00:27:23 -0700349 md = NULL;
350 goto out;
351 }
352
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 dm_get(md);
Alasdair G Kergon5c6bd752006-06-26 00:27:34 -0700354 atomic_inc(&md->open_count);
Jeff Mahoneyfba9f902006-06-26 00:27:23 -0700355
356out:
357 spin_unlock(&_minor_lock);
358
359 return md ? 0 : -ENXIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360}
361
Al Virofe5f9f22008-03-02 10:29:31 -0500362static int dm_blk_close(struct gendisk *disk, fmode_t mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363{
Al Virofe5f9f22008-03-02 10:29:31 -0500364 struct mapped_device *md = disk->private_data;
Alasdair G Kergon5c6bd752006-06-26 00:27:34 -0700365 atomic_dec(&md->open_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 dm_put(md);
367 return 0;
368}
369
Alasdair G Kergon5c6bd752006-06-26 00:27:34 -0700370int dm_open_count(struct mapped_device *md)
371{
372 return atomic_read(&md->open_count);
373}
374
375/*
376 * Guarantees nothing is using the device before it's deleted.
377 */
378int dm_lock_for_deletion(struct mapped_device *md)
379{
380 int r = 0;
381
382 spin_lock(&_minor_lock);
383
384 if (dm_open_count(md))
385 r = -EBUSY;
386 else
387 set_bit(DMF_DELETING, &md->flags);
388
389 spin_unlock(&_minor_lock);
390
391 return r;
392}
393
Darrick J. Wong3ac51e72006-03-27 01:17:54 -0800394static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
395{
396 struct mapped_device *md = bdev->bd_disk->private_data;
397
398 return dm_get_geometry(md, geo);
399}
400
Al Virofe5f9f22008-03-02 10:29:31 -0500401static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
Milan Brozaa129a22006-10-03 01:15:15 -0700402 unsigned int cmd, unsigned long arg)
403{
Al Virofe5f9f22008-03-02 10:29:31 -0500404 struct mapped_device *md = bdev->bd_disk->private_data;
Alasdair G Kergon7c666412009-12-10 23:52:19 +0000405 struct dm_table *map = dm_get_live_table(md);
Milan Brozaa129a22006-10-03 01:15:15 -0700406 struct dm_target *tgt;
407 int r = -ENOTTY;
408
Milan Brozaa129a22006-10-03 01:15:15 -0700409 if (!map || !dm_table_get_size(map))
410 goto out;
411
412 /* We only support devices that have a single target */
413 if (dm_table_get_num_targets(map) != 1)
414 goto out;
415
416 tgt = dm_table_get_target(map, 0);
417
Kiyoshi Ueda4f186f82009-12-10 23:52:26 +0000418 if (dm_suspended_md(md)) {
Milan Brozaa129a22006-10-03 01:15:15 -0700419 r = -EAGAIN;
420 goto out;
421 }
422
423 if (tgt->type->ioctl)
Al Viro647b3d02007-08-28 22:15:59 -0400424 r = tgt->type->ioctl(tgt, cmd, arg);
Milan Brozaa129a22006-10-03 01:15:15 -0700425
426out:
427 dm_table_put(map);
428
Milan Brozaa129a22006-10-03 01:15:15 -0700429 return r;
430}
431
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100432static struct dm_io *alloc_io(struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433{
434 return mempool_alloc(md->io_pool, GFP_NOIO);
435}
436
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100437static void free_io(struct mapped_device *md, struct dm_io *io)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438{
439 mempool_free(io, md->io_pool);
440}
441
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100442static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443{
444 mempool_free(tio, md->tio_pool);
445}
446
Kiyoshi Ueda08885642009-12-10 23:52:15 +0000447static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md,
448 gfp_t gfp_mask)
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100449{
Kiyoshi Ueda08885642009-12-10 23:52:15 +0000450 return mempool_alloc(md->tio_pool, gfp_mask);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100451}
452
453static void free_rq_tio(struct dm_rq_target_io *tio)
454{
455 mempool_free(tio, tio->md->tio_pool);
456}
457
458static struct dm_rq_clone_bio_info *alloc_bio_info(struct mapped_device *md)
459{
460 return mempool_alloc(md->io_pool, GFP_ATOMIC);
461}
462
463static void free_bio_info(struct dm_rq_clone_bio_info *info)
464{
465 mempool_free(info, info->tio->md->io_pool);
466}
467
Kiyoshi Ueda90abb8c2009-12-10 23:52:13 +0000468static int md_in_flight(struct mapped_device *md)
469{
470 return atomic_read(&md->pending[READ]) +
471 atomic_read(&md->pending[WRITE]);
472}
473
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -0800474static void start_io_acct(struct dm_io *io)
475{
476 struct mapped_device *md = io->md;
Tejun Heoc9959052008-08-25 19:47:21 +0900477 int cpu;
Nikanth Karthikesan316d3152009-10-06 20:16:55 +0200478 int rw = bio_data_dir(io->bio);
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -0800479
480 io->start_time = jiffies;
481
Tejun Heo074a7ac2008-08-25 19:56:14 +0900482 cpu = part_stat_lock();
483 part_round_stats(cpu, &dm_disk(md)->part0);
484 part_stat_unlock();
Nikanth Karthikesan316d3152009-10-06 20:16:55 +0200485 dm_disk(md)->part0.in_flight[rw] = atomic_inc_return(&md->pending[rw]);
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -0800486}
487
Mikulas Patockad221d2e2008-11-13 23:39:10 +0000488static void end_io_acct(struct dm_io *io)
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -0800489{
490 struct mapped_device *md = io->md;
491 struct bio *bio = io->bio;
492 unsigned long duration = jiffies - io->start_time;
Tejun Heoc9959052008-08-25 19:47:21 +0900493 int pending, cpu;
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -0800494 int rw = bio_data_dir(bio);
495
Tejun Heo074a7ac2008-08-25 19:56:14 +0900496 cpu = part_stat_lock();
497 part_round_stats(cpu, &dm_disk(md)->part0);
498 part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration);
499 part_stat_unlock();
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -0800500
Mikulas Patockaaf7e4662009-04-09 00:27:16 +0100501 /*
502 * After this is decremented the bio must not be touched if it is
503 * a barrier.
504 */
Nikanth Karthikesan316d3152009-10-06 20:16:55 +0200505 dm_disk(md)->part0.in_flight[rw] = pending =
506 atomic_dec_return(&md->pending[rw]);
507 pending += atomic_read(&md->pending[rw^0x1]);
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -0800508
Mikulas Patockad221d2e2008-11-13 23:39:10 +0000509 /* nudge anyone waiting on suspend queue */
510 if (!pending)
511 wake_up(&md->wait);
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -0800512}
513
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514/*
515 * Add the bio to the list of deferred io.
516 */
Mikulas Patocka92c63902009-04-09 00:27:15 +0100517static void queue_io(struct mapped_device *md, struct bio *bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518{
Alasdair G Kergon2ca33102005-07-28 21:16:00 -0700519 down_write(&md->io_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
Mikulas Patocka022c2612009-04-02 19:55:39 +0100521 spin_lock_irq(&md->deferred_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 bio_list_add(&md->deferred, bio);
Mikulas Patocka022c2612009-04-02 19:55:39 +0100523 spin_unlock_irq(&md->deferred_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
Mikulas Patocka92c63902009-04-09 00:27:15 +0100525 if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags))
526 queue_work(md->wq, &md->work);
527
Alasdair G Kergon2ca33102005-07-28 21:16:00 -0700528 up_write(&md->io_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529}
530
531/*
532 * Everyone (including functions in this file), should use this
533 * function to access the md->map field, and make sure they call
534 * dm_table_put() when finished.
535 */
Alasdair G Kergon7c666412009-12-10 23:52:19 +0000536struct dm_table *dm_get_live_table(struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537{
538 struct dm_table *t;
Kiyoshi Ueda523d9292009-06-22 10:12:37 +0100539 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
Kiyoshi Ueda523d9292009-06-22 10:12:37 +0100541 read_lock_irqsave(&md->map_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 t = md->map;
543 if (t)
544 dm_table_get(t);
Kiyoshi Ueda523d9292009-06-22 10:12:37 +0100545 read_unlock_irqrestore(&md->map_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
547 return t;
548}
549
Darrick J. Wong3ac51e72006-03-27 01:17:54 -0800550/*
551 * Get the geometry associated with a dm device
552 */
553int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
554{
555 *geo = md->geometry;
556
557 return 0;
558}
559
560/*
561 * Set the geometry of a device.
562 */
563int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
564{
565 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
566
567 if (geo->start > sz) {
568 DMWARN("Start sector is beyond the geometry limits.");
569 return -EINVAL;
570 }
571
572 md->geometry = *geo;
573
574 return 0;
575}
576
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577/*-----------------------------------------------------------------
578 * CRUD START:
579 * A more elegant soln is in the works that uses the queue
580 * merge fn, unfortunately there are a couple of changes to
581 * the block layer that I want to make for this. So in the
582 * interests of getting something for people to use I give
583 * you this clearly demarcated crap.
584 *---------------------------------------------------------------*/
585
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800586static int __noflush_suspending(struct mapped_device *md)
587{
588 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
589}
590
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591/*
592 * Decrements the number of outstanding ios that a bio has been
593 * cloned into, completing the original io if necc.
594 */
Arjan van de Ven858119e2006-01-14 13:20:43 -0800595static void dec_pending(struct dm_io *io, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596{
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800597 unsigned long flags;
Milan Brozb35f8ca2009-03-16 17:44:36 +0000598 int io_error;
599 struct bio *bio;
600 struct mapped_device *md = io->md;
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800601
602 /* Push-back supersedes any I/O errors */
Kiyoshi Uedaf88fb982009-10-16 23:18:15 +0100603 if (unlikely(error)) {
604 spin_lock_irqsave(&io->endio_lock, flags);
605 if (!(io->error > 0 && __noflush_suspending(md)))
606 io->error = error;
607 spin_unlock_irqrestore(&io->endio_lock, flags);
608 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
610 if (atomic_dec_and_test(&io->io_count)) {
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800611 if (io->error == DM_ENDIO_REQUEUE) {
612 /*
613 * Target requested pushing back the I/O.
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800614 */
Mikulas Patocka022c2612009-04-02 19:55:39 +0100615 spin_lock_irqsave(&md->deferred_lock, flags);
Mikulas Patocka2761e952009-06-22 10:12:18 +0100616 if (__noflush_suspending(md)) {
Jens Axboe1f98a132009-09-11 14:32:04 +0200617 if (!bio_rw_flagged(io->bio, BIO_RW_BARRIER))
Mikulas Patocka2761e952009-06-22 10:12:18 +0100618 bio_list_add_head(&md->deferred,
619 io->bio);
620 } else
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800621 /* noflush suspend was interrupted. */
622 io->error = -EIO;
Mikulas Patocka022c2612009-04-02 19:55:39 +0100623 spin_unlock_irqrestore(&md->deferred_lock, flags);
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800624 }
625
Milan Brozb35f8ca2009-03-16 17:44:36 +0000626 io_error = io->error;
627 bio = io->bio;
Jens Axboe2056a782006-03-23 20:00:26 +0100628
Jens Axboe1f98a132009-09-11 14:32:04 +0200629 if (bio_rw_flagged(bio, BIO_RW_BARRIER)) {
Mikulas Patockaaf7e4662009-04-09 00:27:16 +0100630 /*
631 * There can be just one barrier request so we use
632 * a per-device variable for error reporting.
633 * Note that you can't touch the bio after end_io_acct
634 */
Mikulas Patockafdb95722009-06-22 10:12:19 +0100635 if (!md->barrier_error && io_error != -EOPNOTSUPP)
Mikulas Patocka5aa27812009-06-22 10:12:18 +0100636 md->barrier_error = io_error;
Mikulas Patockaaf7e4662009-04-09 00:27:16 +0100637 end_io_acct(io);
638 } else {
639 end_io_acct(io);
Milan Brozb35f8ca2009-03-16 17:44:36 +0000640
Mikulas Patockaaf7e4662009-04-09 00:27:16 +0100641 if (io_error != DM_ENDIO_REQUEUE) {
642 trace_block_bio_complete(md->queue, bio);
Milan Brozb35f8ca2009-03-16 17:44:36 +0000643
Mikulas Patockaaf7e4662009-04-09 00:27:16 +0100644 bio_endio(bio, io_error);
645 }
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800646 }
Mikulas Patockaaf7e4662009-04-09 00:27:16 +0100647
648 free_io(md, io);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 }
650}
651
NeilBrown6712ecf2007-09-27 12:47:43 +0200652static void clone_endio(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653{
654 int r = 0;
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100655 struct dm_target_io *tio = bio->bi_private;
Milan Brozb35f8ca2009-03-16 17:44:36 +0000656 struct dm_io *io = tio->io;
Stefan Bader9faf4002006-10-03 01:15:41 -0700657 struct mapped_device *md = tio->io->md;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 dm_endio_fn endio = tio->ti->type->end_io;
659
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 if (!bio_flagged(bio, BIO_UPTODATE) && !error)
661 error = -EIO;
662
663 if (endio) {
664 r = endio(tio->ti, bio, error, &tio->info);
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -0800665 if (r < 0 || r == DM_ENDIO_REQUEUE)
666 /*
667 * error and requeue request are handled
668 * in dec_pending().
669 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 error = r;
Kiyoshi Ueda45cbcd72006-12-08 02:41:05 -0800671 else if (r == DM_ENDIO_INCOMPLETE)
672 /* The target will handle the io */
NeilBrown6712ecf2007-09-27 12:47:43 +0200673 return;
Kiyoshi Ueda45cbcd72006-12-08 02:41:05 -0800674 else if (r) {
675 DMWARN("unimplemented target endio return value: %d", r);
676 BUG();
677 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 }
679
Stefan Bader9faf4002006-10-03 01:15:41 -0700680 /*
681 * Store md for cleanup instead of tio which is about to get freed.
682 */
683 bio->bi_private = md->bs;
684
Stefan Bader9faf4002006-10-03 01:15:41 -0700685 free_tio(md, tio);
Milan Brozb35f8ca2009-03-16 17:44:36 +0000686 bio_put(bio);
687 dec_pending(io, error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688}
689
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100690/*
691 * Partial completion handling for request-based dm
692 */
693static void end_clone_bio(struct bio *clone, int error)
694{
695 struct dm_rq_clone_bio_info *info = clone->bi_private;
696 struct dm_rq_target_io *tio = info->tio;
697 struct bio *bio = info->orig;
698 unsigned int nr_bytes = info->orig->bi_size;
699
700 bio_put(clone);
701
702 if (tio->error)
703 /*
704 * An error has already been detected on the request.
705 * Once error occurred, just let clone->end_io() handle
706 * the remainder.
707 */
708 return;
709 else if (error) {
710 /*
711 * Don't notice the error to the upper layer yet.
712 * The error handling decision is made by the target driver,
713 * when the request is completed.
714 */
715 tio->error = error;
716 return;
717 }
718
719 /*
720 * I/O for the bio successfully completed.
721 * Notice the data completion to the upper layer.
722 */
723
724 /*
725 * bios are processed from the head of the list.
726 * So the completing bio should always be rq->bio.
727 * If it's not, something wrong is happening.
728 */
729 if (tio->orig->bio != bio)
730 DMERR("bio completion is going in the middle of the request");
731
732 /*
733 * Update the original request.
734 * Do not use blk_end_request() here, because it may complete
735 * the original request before the clone, and break the ordering.
736 */
737 blk_update_request(tio->orig, 0, nr_bytes);
738}
739
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000740static void store_barrier_error(struct mapped_device *md, int error)
741{
742 unsigned long flags;
743
744 spin_lock_irqsave(&md->barrier_error_lock, flags);
745 /*
746 * Basically, the first error is taken, but:
747 * -EOPNOTSUPP supersedes any I/O error.
748 * Requeue request supersedes any I/O error but -EOPNOTSUPP.
749 */
750 if (!md->barrier_error || error == -EOPNOTSUPP ||
751 (md->barrier_error != -EOPNOTSUPP &&
752 error == DM_ENDIO_REQUEUE))
753 md->barrier_error = error;
754 spin_unlock_irqrestore(&md->barrier_error_lock, flags);
755}
756
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100757/*
758 * Don't touch any member of the md after calling this function because
759 * the md may be freed in dm_put() at the end of this function.
760 * Or do dm_get() before calling this function and dm_put() later.
761 */
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +0000762static void rq_completed(struct mapped_device *md, int rw, int run_queue)
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100763{
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +0000764 atomic_dec(&md->pending[rw]);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100765
766 /* nudge anyone waiting on suspend queue */
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +0000767 if (!md_in_flight(md))
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100768 wake_up(&md->wait);
769
770 if (run_queue)
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +0000771 blk_run_queue(md->queue);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100772
773 /*
774 * dm_put() must be at the end of this function. See the comment above
775 */
776 dm_put(md);
777}
778
Kiyoshi Uedaa77e28c2009-09-04 20:40:16 +0100779static void free_rq_clone(struct request *clone)
780{
781 struct dm_rq_target_io *tio = clone->end_io_data;
782
783 blk_rq_unprep_clone(clone);
784 free_rq_tio(tio);
785}
786
Kiyoshi Ueda980691e2009-12-10 23:52:17 +0000787/*
788 * Complete the clone and the original request.
789 * Must be called without queue lock.
790 */
791static void dm_end_request(struct request *clone, int error)
792{
793 int rw = rq_data_dir(clone);
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000794 int run_queue = 1;
795 bool is_barrier = blk_barrier_rq(clone);
Kiyoshi Ueda980691e2009-12-10 23:52:17 +0000796 struct dm_rq_target_io *tio = clone->end_io_data;
797 struct mapped_device *md = tio->md;
798 struct request *rq = tio->orig;
799
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000800 if (blk_pc_request(rq) && !is_barrier) {
Kiyoshi Ueda980691e2009-12-10 23:52:17 +0000801 rq->errors = clone->errors;
802 rq->resid_len = clone->resid_len;
803
804 if (rq->sense)
805 /*
806 * We are using the sense buffer of the original
807 * request.
808 * So setting the length of the sense data is enough.
809 */
810 rq->sense_len = clone->sense_len;
811 }
812
813 free_rq_clone(clone);
814
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000815 if (unlikely(is_barrier)) {
816 if (unlikely(error))
817 store_barrier_error(md, error);
818 run_queue = 0;
819 } else
820 blk_end_request_all(rq, error);
Kiyoshi Ueda980691e2009-12-10 23:52:17 +0000821
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000822 rq_completed(md, rw, run_queue);
Kiyoshi Ueda980691e2009-12-10 23:52:17 +0000823}
824
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100825static void dm_unprep_request(struct request *rq)
826{
827 struct request *clone = rq->special;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100828
829 rq->special = NULL;
830 rq->cmd_flags &= ~REQ_DONTPREP;
831
Kiyoshi Uedaa77e28c2009-09-04 20:40:16 +0100832 free_rq_clone(clone);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100833}
834
835/*
836 * Requeue the original request of a clone.
837 */
838void dm_requeue_unmapped_request(struct request *clone)
839{
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +0000840 int rw = rq_data_dir(clone);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100841 struct dm_rq_target_io *tio = clone->end_io_data;
842 struct mapped_device *md = tio->md;
843 struct request *rq = tio->orig;
844 struct request_queue *q = rq->q;
845 unsigned long flags;
846
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000847 if (unlikely(blk_barrier_rq(clone))) {
848 /*
849 * Barrier clones share an original request.
850 * Leave it to dm_end_request(), which handles this special
851 * case.
852 */
853 dm_end_request(clone, DM_ENDIO_REQUEUE);
854 return;
855 }
856
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100857 dm_unprep_request(rq);
858
859 spin_lock_irqsave(q->queue_lock, flags);
860 if (elv_queue_empty(q))
861 blk_plug_device(q);
862 blk_requeue_request(q, rq);
863 spin_unlock_irqrestore(q->queue_lock, flags);
864
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +0000865 rq_completed(md, rw, 0);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100866}
867EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request);
868
869static void __stop_queue(struct request_queue *q)
870{
871 blk_stop_queue(q);
872}
873
874static void stop_queue(struct request_queue *q)
875{
876 unsigned long flags;
877
878 spin_lock_irqsave(q->queue_lock, flags);
879 __stop_queue(q);
880 spin_unlock_irqrestore(q->queue_lock, flags);
881}
882
883static void __start_queue(struct request_queue *q)
884{
885 if (blk_queue_stopped(q))
886 blk_start_queue(q);
887}
888
889static void start_queue(struct request_queue *q)
890{
891 unsigned long flags;
892
893 spin_lock_irqsave(q->queue_lock, flags);
894 __start_queue(q);
895 spin_unlock_irqrestore(q->queue_lock, flags);
896}
897
Kiyoshi Ueda11a68242009-12-10 23:52:17 +0000898static void dm_done(struct request *clone, int error, bool mapped)
899{
900 int r = error;
901 struct dm_rq_target_io *tio = clone->end_io_data;
902 dm_request_endio_fn rq_end_io = tio->ti->type->rq_end_io;
903
904 if (mapped && rq_end_io)
905 r = rq_end_io(tio->ti, clone, error, &tio->info);
906
907 if (r <= 0)
908 /* The target wants to complete the I/O */
909 dm_end_request(clone, r);
910 else if (r == DM_ENDIO_INCOMPLETE)
911 /* The target will handle the I/O */
912 return;
913 else if (r == DM_ENDIO_REQUEUE)
914 /* The target wants to requeue the I/O */
915 dm_requeue_unmapped_request(clone);
916 else {
917 DMWARN("unimplemented target endio return value: %d", r);
918 BUG();
919 }
920}
921
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100922/*
923 * Request completion handler for request-based dm
924 */
925static void dm_softirq_done(struct request *rq)
926{
Kiyoshi Ueda11a68242009-12-10 23:52:17 +0000927 bool mapped = true;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100928 struct request *clone = rq->completion_data;
929 struct dm_rq_target_io *tio = clone->end_io_data;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100930
Kiyoshi Ueda11a68242009-12-10 23:52:17 +0000931 if (rq->cmd_flags & REQ_FAILED)
932 mapped = false;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100933
Kiyoshi Ueda11a68242009-12-10 23:52:17 +0000934 dm_done(clone, tio->error, mapped);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100935}
936
937/*
938 * Complete the clone and the original request with the error status
939 * through softirq context.
940 */
941static void dm_complete_request(struct request *clone, int error)
942{
943 struct dm_rq_target_io *tio = clone->end_io_data;
944 struct request *rq = tio->orig;
945
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000946 if (unlikely(blk_barrier_rq(clone))) {
947 /*
948 * Barrier clones share an original request. So can't use
949 * softirq_done with the original.
950 * Pass the clone to dm_done() directly in this special case.
951 * It is safe (even if clone->q->queue_lock is held here)
952 * because there is no I/O dispatching during the completion
953 * of barrier clone.
954 */
955 dm_done(clone, error, true);
956 return;
957 }
958
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100959 tio->error = error;
960 rq->completion_data = clone;
961 blk_complete_request(rq);
962}
963
964/*
965 * Complete the not-mapped clone and the original request with the error status
966 * through softirq context.
967 * Target's rq_end_io() function isn't called.
968 * This may be used when the target's map_rq() function fails.
969 */
970void dm_kill_unmapped_request(struct request *clone, int error)
971{
972 struct dm_rq_target_io *tio = clone->end_io_data;
973 struct request *rq = tio->orig;
974
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +0000975 if (unlikely(blk_barrier_rq(clone))) {
976 /*
977 * Barrier clones share an original request.
978 * Leave it to dm_end_request(), which handles this special
979 * case.
980 */
981 BUG_ON(error > 0);
982 dm_end_request(clone, error);
983 return;
984 }
985
Kiyoshi Uedacec47e32009-06-22 10:12:35 +0100986 rq->cmd_flags |= REQ_FAILED;
987 dm_complete_request(clone, error);
988}
989EXPORT_SYMBOL_GPL(dm_kill_unmapped_request);
990
991/*
992 * Called with the queue lock held
993 */
994static void end_clone_request(struct request *clone, int error)
995{
996 /*
997 * For just cleaning up the information of the queue in which
998 * the clone was dispatched.
999 * The clone is *NOT* freed actually here because it is alloced from
1000 * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags.
1001 */
1002 __blk_put_request(clone->q, clone);
1003
1004 /*
1005 * Actual request completion is done in a softirq context which doesn't
1006 * hold the queue lock. Otherwise, deadlock could occur because:
1007 * - another request may be submitted by the upper level driver
1008 * of the stacking during the completion
1009 * - the submission which requires queue lock may be done
1010 * against this queue
1011 */
1012 dm_complete_request(clone, error);
1013}
1014
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015static sector_t max_io_len(struct mapped_device *md,
1016 sector_t sector, struct dm_target *ti)
1017{
1018 sector_t offset = sector - ti->begin;
1019 sector_t len = ti->len - offset;
1020
1021 /*
1022 * Does the target need to split even further ?
1023 */
1024 if (ti->split_io) {
1025 sector_t boundary;
1026 boundary = ((offset + ti->split_io) & ~(ti->split_io - 1))
1027 - offset;
1028 if (len > boundary)
1029 len = boundary;
1030 }
1031
1032 return len;
1033}
1034
1035static void __map_bio(struct dm_target *ti, struct bio *clone,
Alasdair G Kergon028867a2007-07-12 17:26:32 +01001036 struct dm_target_io *tio)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037{
1038 int r;
Jens Axboe2056a782006-03-23 20:00:26 +01001039 sector_t sector;
Stefan Bader9faf4002006-10-03 01:15:41 -07001040 struct mapped_device *md;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 clone->bi_end_io = clone_endio;
1043 clone->bi_private = tio;
1044
1045 /*
1046 * Map the clone. If r == 0 we don't need to do
1047 * anything, the target has assumed ownership of
1048 * this io.
1049 */
1050 atomic_inc(&tio->io->io_count);
Jens Axboe2056a782006-03-23 20:00:26 +01001051 sector = clone->bi_sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 r = ti->type->map(ti, clone, &tio->info);
Kiyoshi Ueda45cbcd72006-12-08 02:41:05 -08001053 if (r == DM_MAPIO_REMAPPED) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 /* the bio has been remapped so dispatch it */
Jens Axboe2056a782006-03-23 20:00:26 +01001055
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001056 trace_block_remap(bdev_get_queue(clone->bi_bdev), clone,
Alan D. Brunelle22a7c312009-05-04 16:35:08 -04001057 tio->io->bio->bi_bdev->bd_dev, sector);
Jens Axboe2056a782006-03-23 20:00:26 +01001058
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 generic_make_request(clone);
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -08001060 } else if (r < 0 || r == DM_MAPIO_REQUEUE) {
1061 /* error the io and bail out, or requeue it if needed */
Stefan Bader9faf4002006-10-03 01:15:41 -07001062 md = tio->io->md;
1063 dec_pending(tio->io, r);
1064 /*
1065 * Store bio_set for cleanup.
1066 */
1067 clone->bi_private = md->bs;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068 bio_put(clone);
Stefan Bader9faf4002006-10-03 01:15:41 -07001069 free_tio(md, tio);
Kiyoshi Ueda45cbcd72006-12-08 02:41:05 -08001070 } else if (r) {
1071 DMWARN("unimplemented target map return value: %d", r);
1072 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073 }
1074}
1075
1076struct clone_info {
1077 struct mapped_device *md;
1078 struct dm_table *map;
1079 struct bio *bio;
1080 struct dm_io *io;
1081 sector_t sector;
1082 sector_t sector_count;
1083 unsigned short idx;
1084};
1085
Peter Osterlund36763472005-09-06 15:16:42 -07001086static void dm_bio_destructor(struct bio *bio)
1087{
Stefan Bader9faf4002006-10-03 01:15:41 -07001088 struct bio_set *bs = bio->bi_private;
1089
1090 bio_free(bio, bs);
Peter Osterlund36763472005-09-06 15:16:42 -07001091}
1092
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093/*
1094 * Creates a little bio that is just does part of a bvec.
1095 */
1096static struct bio *split_bvec(struct bio *bio, sector_t sector,
1097 unsigned short idx, unsigned int offset,
Stefan Bader9faf4002006-10-03 01:15:41 -07001098 unsigned int len, struct bio_set *bs)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099{
1100 struct bio *clone;
1101 struct bio_vec *bv = bio->bi_io_vec + idx;
1102
Stefan Bader9faf4002006-10-03 01:15:41 -07001103 clone = bio_alloc_bioset(GFP_NOIO, 1, bs);
Peter Osterlund36763472005-09-06 15:16:42 -07001104 clone->bi_destructor = dm_bio_destructor;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 *clone->bi_io_vec = *bv;
1106
1107 clone->bi_sector = sector;
1108 clone->bi_bdev = bio->bi_bdev;
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01001109 clone->bi_rw = bio->bi_rw & ~(1 << BIO_RW_BARRIER);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 clone->bi_vcnt = 1;
1111 clone->bi_size = to_bytes(len);
1112 clone->bi_io_vec->bv_offset = offset;
1113 clone->bi_io_vec->bv_len = clone->bi_size;
Martin K. Petersenf3e1d262008-10-21 17:45:04 +01001114 clone->bi_flags |= 1 << BIO_CLONED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115
Martin K. Petersen9c470082009-04-09 00:27:12 +01001116 if (bio_integrity(bio)) {
Martin K. Petersen7878cba2009-06-26 15:37:49 +02001117 bio_integrity_clone(clone, bio, GFP_NOIO, bs);
Martin K. Petersen9c470082009-04-09 00:27:12 +01001118 bio_integrity_trim(clone,
1119 bio_sector_offset(bio, idx, offset), len);
1120 }
1121
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 return clone;
1123}
1124
1125/*
1126 * Creates a bio that consists of range of complete bvecs.
1127 */
1128static struct bio *clone_bio(struct bio *bio, sector_t sector,
1129 unsigned short idx, unsigned short bv_count,
Stefan Bader9faf4002006-10-03 01:15:41 -07001130 unsigned int len, struct bio_set *bs)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131{
1132 struct bio *clone;
1133
Stefan Bader9faf4002006-10-03 01:15:41 -07001134 clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
1135 __bio_clone(clone, bio);
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01001136 clone->bi_rw &= ~(1 << BIO_RW_BARRIER);
Stefan Bader9faf4002006-10-03 01:15:41 -07001137 clone->bi_destructor = dm_bio_destructor;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 clone->bi_sector = sector;
1139 clone->bi_idx = idx;
1140 clone->bi_vcnt = idx + bv_count;
1141 clone->bi_size = to_bytes(len);
1142 clone->bi_flags &= ~(1 << BIO_SEG_VALID);
1143
Martin K. Petersen9c470082009-04-09 00:27:12 +01001144 if (bio_integrity(bio)) {
Martin K. Petersen7878cba2009-06-26 15:37:49 +02001145 bio_integrity_clone(clone, bio, GFP_NOIO, bs);
Martin K. Petersen9c470082009-04-09 00:27:12 +01001146
1147 if (idx != bio->bi_idx || clone->bi_size < bio->bi_size)
1148 bio_integrity_trim(clone,
1149 bio_sector_offset(bio, idx, 0), len);
1150 }
1151
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 return clone;
1153}
1154
Alasdair G Kergon9015df22009-06-22 10:12:21 +01001155static struct dm_target_io *alloc_tio(struct clone_info *ci,
1156 struct dm_target *ti)
Mikulas Patockaf9ab94c2009-06-22 10:12:20 +01001157{
Alasdair G Kergon9015df22009-06-22 10:12:21 +01001158 struct dm_target_io *tio = mempool_alloc(ci->md->tio_pool, GFP_NOIO);
Mikulas Patockaf9ab94c2009-06-22 10:12:20 +01001159
1160 tio->io = ci->io;
1161 tio->ti = ti;
Mikulas Patockaf9ab94c2009-06-22 10:12:20 +01001162 memset(&tio->info, 0, sizeof(tio->info));
Alasdair G Kergon9015df22009-06-22 10:12:21 +01001163
1164 return tio;
1165}
1166
1167static void __flush_target(struct clone_info *ci, struct dm_target *ti,
1168 unsigned flush_nr)
1169{
1170 struct dm_target_io *tio = alloc_tio(ci, ti);
1171 struct bio *clone;
1172
Mikulas Patockaf9ab94c2009-06-22 10:12:20 +01001173 tio->info.flush_request = flush_nr;
1174
1175 clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
1176 __bio_clone(clone, ci->bio);
1177 clone->bi_destructor = dm_bio_destructor;
1178
1179 __map_bio(ti, clone, tio);
1180}
1181
1182static int __clone_and_map_empty_barrier(struct clone_info *ci)
1183{
1184 unsigned target_nr = 0, flush_nr;
1185 struct dm_target *ti;
1186
1187 while ((ti = dm_table_get_target(ci->map, target_nr++)))
1188 for (flush_nr = 0; flush_nr < ti->num_flush_requests;
1189 flush_nr++)
1190 __flush_target(ci, ti, flush_nr);
1191
1192 ci->sector_count = 0;
1193
1194 return 0;
1195}
1196
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001197static int __clone_and_map(struct clone_info *ci)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198{
1199 struct bio *clone, *bio = ci->bio;
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001200 struct dm_target *ti;
1201 sector_t len = 0, max;
Alasdair G Kergon028867a2007-07-12 17:26:32 +01001202 struct dm_target_io *tio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203
Mikulas Patockaf9ab94c2009-06-22 10:12:20 +01001204 if (unlikely(bio_empty_barrier(bio)))
1205 return __clone_and_map_empty_barrier(ci);
1206
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001207 ti = dm_table_find_target(ci->map, ci->sector);
1208 if (!dm_target_is_valid(ti))
1209 return -EIO;
1210
1211 max = max_io_len(ci->md, ci->sector, ti);
1212
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 /*
1214 * Allocate a target io object.
1215 */
Alasdair G Kergon9015df22009-06-22 10:12:21 +01001216 tio = alloc_tio(ci, ti);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217
1218 if (ci->sector_count <= max) {
1219 /*
1220 * Optimise for the simple case where we can do all of
1221 * the remaining io with a single clone.
1222 */
1223 clone = clone_bio(bio, ci->sector, ci->idx,
Stefan Bader9faf4002006-10-03 01:15:41 -07001224 bio->bi_vcnt - ci->idx, ci->sector_count,
1225 ci->md->bs);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 __map_bio(ti, clone, tio);
1227 ci->sector_count = 0;
1228
1229 } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) {
1230 /*
1231 * There are some bvecs that don't span targets.
1232 * Do as many of these as possible.
1233 */
1234 int i;
1235 sector_t remaining = max;
1236 sector_t bv_len;
1237
1238 for (i = ci->idx; remaining && (i < bio->bi_vcnt); i++) {
1239 bv_len = to_sector(bio->bi_io_vec[i].bv_len);
1240
1241 if (bv_len > remaining)
1242 break;
1243
1244 remaining -= bv_len;
1245 len += bv_len;
1246 }
1247
Stefan Bader9faf4002006-10-03 01:15:41 -07001248 clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len,
1249 ci->md->bs);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 __map_bio(ti, clone, tio);
1251
1252 ci->sector += len;
1253 ci->sector_count -= len;
1254 ci->idx = i;
1255
1256 } else {
1257 /*
Alasdair G Kergond2044a92006-03-22 00:07:42 -08001258 * Handle a bvec that must be split between two or more targets.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 */
1260 struct bio_vec *bv = bio->bi_io_vec + ci->idx;
Alasdair G Kergond2044a92006-03-22 00:07:42 -08001261 sector_t remaining = to_sector(bv->bv_len);
1262 unsigned int offset = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263
Alasdair G Kergond2044a92006-03-22 00:07:42 -08001264 do {
1265 if (offset) {
1266 ti = dm_table_find_target(ci->map, ci->sector);
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001267 if (!dm_target_is_valid(ti))
1268 return -EIO;
1269
Alasdair G Kergond2044a92006-03-22 00:07:42 -08001270 max = max_io_len(ci->md, ci->sector, ti);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271
Alasdair G Kergon9015df22009-06-22 10:12:21 +01001272 tio = alloc_tio(ci, ti);
Alasdair G Kergond2044a92006-03-22 00:07:42 -08001273 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274
Alasdair G Kergond2044a92006-03-22 00:07:42 -08001275 len = min(remaining, max);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276
Alasdair G Kergond2044a92006-03-22 00:07:42 -08001277 clone = split_bvec(bio, ci->sector, ci->idx,
Stefan Bader9faf4002006-10-03 01:15:41 -07001278 bv->bv_offset + offset, len,
1279 ci->md->bs);
Alasdair G Kergond2044a92006-03-22 00:07:42 -08001280
1281 __map_bio(ti, clone, tio);
1282
1283 ci->sector += len;
1284 ci->sector_count -= len;
1285 offset += to_bytes(len);
1286 } while (remaining -= len);
1287
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 ci->idx++;
1289 }
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001290
1291 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292}
1293
1294/*
Mikulas Patocka8a53c282009-04-02 19:55:37 +01001295 * Split the bio into several clones and submit it to targets.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 */
Mikulas Patockaf0b9a452009-04-02 19:55:38 +01001297static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298{
1299 struct clone_info ci;
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001300 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301
Alasdair G Kergon7c666412009-12-10 23:52:19 +00001302 ci.map = dm_get_live_table(md);
Mikulas Patockaf0b9a452009-04-02 19:55:38 +01001303 if (unlikely(!ci.map)) {
Jens Axboe1f98a132009-09-11 14:32:04 +02001304 if (!bio_rw_flagged(bio, BIO_RW_BARRIER))
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01001305 bio_io_error(bio);
1306 else
Mikulas Patocka5aa27812009-06-22 10:12:18 +01001307 if (!md->barrier_error)
1308 md->barrier_error = -EIO;
Mikulas Patockaf0b9a452009-04-02 19:55:38 +01001309 return;
1310 }
Mikulas Patocka692d0eb2009-04-09 00:27:13 +01001311
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 ci.md = md;
1313 ci.bio = bio;
1314 ci.io = alloc_io(md);
1315 ci.io->error = 0;
1316 atomic_set(&ci.io->io_count, 1);
1317 ci.io->bio = bio;
1318 ci.io->md = md;
Kiyoshi Uedaf88fb982009-10-16 23:18:15 +01001319 spin_lock_init(&ci.io->endio_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 ci.sector = bio->bi_sector;
1321 ci.sector_count = bio_sectors(bio);
Mikulas Patockaf9ab94c2009-06-22 10:12:20 +01001322 if (unlikely(bio_empty_barrier(bio)))
1323 ci.sector_count = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 ci.idx = bio->bi_idx;
1325
Jun'ichi "Nick" Nomura3eaf8402006-02-01 03:04:53 -08001326 start_io_acct(ci.io);
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001327 while (ci.sector_count && !error)
1328 error = __clone_and_map(&ci);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329
1330 /* drop the extra reference count */
Jun'ichi Nomura512875b2007-12-13 14:15:25 +00001331 dec_pending(ci.io, error);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 dm_table_put(ci.map);
1333}
1334/*-----------------------------------------------------------------
1335 * CRUD END
1336 *---------------------------------------------------------------*/
1337
Milan Brozf6fccb12008-07-21 12:00:37 +01001338static int dm_merge_bvec(struct request_queue *q,
1339 struct bvec_merge_data *bvm,
1340 struct bio_vec *biovec)
1341{
1342 struct mapped_device *md = q->queuedata;
Alasdair G Kergon7c666412009-12-10 23:52:19 +00001343 struct dm_table *map = dm_get_live_table(md);
Milan Brozf6fccb12008-07-21 12:00:37 +01001344 struct dm_target *ti;
1345 sector_t max_sectors;
Mikulas Patocka50371082008-10-01 14:39:17 +01001346 int max_size = 0;
Milan Brozf6fccb12008-07-21 12:00:37 +01001347
1348 if (unlikely(!map))
Mikulas Patocka50371082008-10-01 14:39:17 +01001349 goto out;
Milan Brozf6fccb12008-07-21 12:00:37 +01001350
1351 ti = dm_table_find_target(map, bvm->bi_sector);
Mikulas Patockab01cd5a2008-10-01 14:39:24 +01001352 if (!dm_target_is_valid(ti))
1353 goto out_table;
Milan Brozf6fccb12008-07-21 12:00:37 +01001354
1355 /*
1356 * Find maximum amount of I/O that won't need splitting
1357 */
1358 max_sectors = min(max_io_len(md, bvm->bi_sector, ti),
1359 (sector_t) BIO_MAX_SECTORS);
1360 max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size;
1361 if (max_size < 0)
1362 max_size = 0;
1363
1364 /*
1365 * merge_bvec_fn() returns number of bytes
1366 * it can accept at this offset
1367 * max is precomputed maximal io size
1368 */
1369 if (max_size && ti->type->merge)
1370 max_size = ti->type->merge(ti, bvm, biovec, max_size);
Mikulas Patocka8cbeb672009-06-22 10:12:14 +01001371 /*
1372 * If the target doesn't support merge method and some of the devices
1373 * provided their merge_bvec method (we know this by looking at
1374 * queue_max_hw_sectors), then we can't allow bios with multiple vector
1375 * entries. So always set max_size to 0, and the code below allows
1376 * just one page.
1377 */
1378 else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9)
1379
1380 max_size = 0;
Milan Brozf6fccb12008-07-21 12:00:37 +01001381
Mikulas Patockab01cd5a2008-10-01 14:39:24 +01001382out_table:
Mikulas Patocka50371082008-10-01 14:39:17 +01001383 dm_table_put(map);
1384
1385out:
Milan Brozf6fccb12008-07-21 12:00:37 +01001386 /*
1387 * Always allow an entire first page
1388 */
1389 if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT))
1390 max_size = biovec->bv_len;
1391
Milan Brozf6fccb12008-07-21 12:00:37 +01001392 return max_size;
1393}
1394
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395/*
1396 * The request function that just remaps the bio built up by
1397 * dm_merge_bvec.
1398 */
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001399static int _dm_request(struct request_queue *q, struct bio *bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400{
Kevin Corry12f03a42006-02-01 03:04:52 -08001401 int rw = bio_data_dir(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 struct mapped_device *md = q->queuedata;
Tejun Heoc9959052008-08-25 19:47:21 +09001403 int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07001405 down_read(&md->io_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406
Tejun Heo074a7ac2008-08-25 19:56:14 +09001407 cpu = part_stat_lock();
1408 part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]);
1409 part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
1410 part_stat_unlock();
Kevin Corry12f03a42006-02-01 03:04:52 -08001411
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 /*
Alasdair G Kergon1eb787e2009-04-09 00:27:14 +01001413 * If we're suspended or the thread is processing barriers
1414 * we have to queue this io for later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415 */
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01001416 if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
Jens Axboe1f98a132009-09-11 14:32:04 +02001417 unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07001418 up_read(&md->io_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419
Alasdair G Kergon54d9a1b2009-04-09 00:27:14 +01001420 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
1421 bio_rw(bio) == READA) {
1422 bio_io_error(bio);
1423 return 0;
1424 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425
Mikulas Patocka92c63902009-04-09 00:27:15 +01001426 queue_io(md, bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427
Mikulas Patocka92c63902009-04-09 00:27:15 +01001428 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429 }
1430
Mikulas Patockaf0b9a452009-04-02 19:55:38 +01001431 __split_and_process_bio(md, bio);
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07001432 up_read(&md->io_lock);
Mikulas Patockaf0b9a452009-04-02 19:55:38 +01001433 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434}
1435
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001436static int dm_make_request(struct request_queue *q, struct bio *bio)
1437{
1438 struct mapped_device *md = q->queuedata;
1439
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001440 return md->saved_make_request_fn(q, bio); /* call __make_request() */
1441}
1442
1443static int dm_request_based(struct mapped_device *md)
1444{
1445 return blk_queue_stackable(md->queue);
1446}
1447
1448static int dm_request(struct request_queue *q, struct bio *bio)
1449{
1450 struct mapped_device *md = q->queuedata;
1451
1452 if (dm_request_based(md))
1453 return dm_make_request(q, bio);
1454
1455 return _dm_request(q, bio);
1456}
1457
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001458/*
1459 * Mark this request as flush request, so that dm_request_fn() can
1460 * recognize.
1461 */
1462static void dm_rq_prepare_flush(struct request_queue *q, struct request *rq)
1463{
1464 rq->cmd_type = REQ_TYPE_LINUX_BLOCK;
1465 rq->cmd[0] = REQ_LB_OP_FLUSH;
1466}
1467
1468static bool dm_rq_is_flush_request(struct request *rq)
1469{
1470 if (rq->cmd_type == REQ_TYPE_LINUX_BLOCK &&
1471 rq->cmd[0] == REQ_LB_OP_FLUSH)
1472 return true;
1473 else
1474 return false;
1475}
1476
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001477void dm_dispatch_request(struct request *rq)
1478{
1479 int r;
1480
1481 if (blk_queue_io_stat(rq->q))
1482 rq->cmd_flags |= REQ_IO_STAT;
1483
1484 rq->start_time = jiffies;
1485 r = blk_insert_cloned_request(rq->q, rq);
1486 if (r)
1487 dm_complete_request(rq, r);
1488}
1489EXPORT_SYMBOL_GPL(dm_dispatch_request);
1490
1491static void dm_rq_bio_destructor(struct bio *bio)
1492{
1493 struct dm_rq_clone_bio_info *info = bio->bi_private;
1494 struct mapped_device *md = info->tio->md;
1495
1496 free_bio_info(info);
1497 bio_free(bio, md->bs);
1498}
1499
1500static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig,
1501 void *data)
1502{
1503 struct dm_rq_target_io *tio = data;
1504 struct mapped_device *md = tio->md;
1505 struct dm_rq_clone_bio_info *info = alloc_bio_info(md);
1506
1507 if (!info)
1508 return -ENOMEM;
1509
1510 info->orig = bio_orig;
1511 info->tio = tio;
1512 bio->bi_end_io = end_clone_bio;
1513 bio->bi_private = info;
1514 bio->bi_destructor = dm_rq_bio_destructor;
1515
1516 return 0;
1517}
1518
1519static int setup_clone(struct request *clone, struct request *rq,
1520 struct dm_rq_target_io *tio)
1521{
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001522 int r;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001523
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001524 if (dm_rq_is_flush_request(rq)) {
1525 blk_rq_init(NULL, clone);
1526 clone->cmd_type = REQ_TYPE_FS;
1527 clone->cmd_flags |= (REQ_HARDBARRIER | WRITE);
1528 } else {
1529 r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
1530 dm_rq_bio_constructor, tio);
1531 if (r)
1532 return r;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001533
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001534 clone->cmd = rq->cmd;
1535 clone->cmd_len = rq->cmd_len;
1536 clone->sense = rq->sense;
1537 clone->buffer = rq->buffer;
1538 }
1539
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001540 clone->end_io = end_clone_request;
1541 clone->end_io_data = tio;
1542
1543 return 0;
1544}
1545
Kiyoshi Ueda6facdaf2009-12-10 23:52:15 +00001546static struct request *clone_rq(struct request *rq, struct mapped_device *md,
1547 gfp_t gfp_mask)
1548{
1549 struct request *clone;
1550 struct dm_rq_target_io *tio;
1551
1552 tio = alloc_rq_tio(md, gfp_mask);
1553 if (!tio)
1554 return NULL;
1555
1556 tio->md = md;
1557 tio->ti = NULL;
1558 tio->orig = rq;
1559 tio->error = 0;
1560 memset(&tio->info, 0, sizeof(tio->info));
1561
1562 clone = &tio->clone;
1563 if (setup_clone(clone, rq, tio)) {
1564 /* -ENOMEM */
1565 free_rq_tio(tio);
1566 return NULL;
1567 }
1568
1569 return clone;
1570}
1571
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001572/*
1573 * Called with the queue lock held.
1574 */
1575static int dm_prep_fn(struct request_queue *q, struct request *rq)
1576{
1577 struct mapped_device *md = q->queuedata;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001578 struct request *clone;
1579
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001580 if (unlikely(dm_rq_is_flush_request(rq)))
1581 return BLKPREP_OK;
1582
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001583 if (unlikely(rq->special)) {
1584 DMWARN("Already has something in rq->special.");
1585 return BLKPREP_KILL;
1586 }
1587
Kiyoshi Ueda6facdaf2009-12-10 23:52:15 +00001588 clone = clone_rq(rq, md, GFP_ATOMIC);
1589 if (!clone)
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001590 return BLKPREP_DEFER;
1591
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001592 rq->special = clone;
1593 rq->cmd_flags |= REQ_DONTPREP;
1594
1595 return BLKPREP_OK;
1596}
1597
Kiyoshi Ueda598de402009-12-10 23:52:14 +00001598static void map_request(struct dm_target *ti, struct request *clone,
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001599 struct mapped_device *md)
1600{
1601 int r;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001602 struct dm_rq_target_io *tio = clone->end_io_data;
1603
1604 /*
1605 * Hold the md reference here for the in-flight I/O.
1606 * We can't rely on the reference count by device opener,
1607 * because the device may be closed during the request completion
1608 * when all bios are completed.
1609 * See the comment in rq_completed() too.
1610 */
1611 dm_get(md);
1612
1613 tio->ti = ti;
1614 r = ti->type->map_rq(ti, clone, &tio->info);
1615 switch (r) {
1616 case DM_MAPIO_SUBMITTED:
1617 /* The target has taken the I/O to submit by itself later */
1618 break;
1619 case DM_MAPIO_REMAPPED:
1620 /* The target has remapped the I/O so dispatch it */
Jun'ichi Nomura6db4ccd2009-12-10 23:52:25 +00001621 trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
1622 blk_rq_pos(tio->orig));
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001623 dm_dispatch_request(clone);
1624 break;
1625 case DM_MAPIO_REQUEUE:
1626 /* The target wants to requeue the I/O */
1627 dm_requeue_unmapped_request(clone);
1628 break;
1629 default:
1630 if (r > 0) {
1631 DMWARN("unimplemented target map return value: %d", r);
1632 BUG();
1633 }
1634
1635 /* The target wants to complete the I/O */
1636 dm_kill_unmapped_request(clone, r);
1637 break;
1638 }
1639}
1640
1641/*
1642 * q->request_fn for request-based dm.
1643 * Called with the queue lock held.
1644 */
1645static void dm_request_fn(struct request_queue *q)
1646{
1647 struct mapped_device *md = q->queuedata;
Alasdair G Kergon7c666412009-12-10 23:52:19 +00001648 struct dm_table *map = dm_get_live_table(md);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001649 struct dm_target *ti;
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +00001650 struct request *rq, *clone;
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001651
1652 /*
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +00001653 * For suspend, check blk_queue_stopped() and increment
1654 * ->pending within a single queue_lock not to increment the
1655 * number of in-flight I/Os after the queue is stopped in
1656 * dm_suspend().
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001657 */
1658 while (!blk_queue_plugged(q) && !blk_queue_stopped(q)) {
1659 rq = blk_peek_request(q);
1660 if (!rq)
1661 goto plug_and_out;
1662
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001663 if (unlikely(dm_rq_is_flush_request(rq))) {
1664 BUG_ON(md->flush_request);
1665 md->flush_request = rq;
1666 blk_start_request(rq);
1667 queue_work(md->wq, &md->barrier_work);
1668 goto out;
1669 }
1670
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001671 ti = dm_table_find_target(map, blk_rq_pos(rq));
1672 if (ti->type->busy && ti->type->busy(ti))
1673 goto plug_and_out;
1674
1675 blk_start_request(rq);
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +00001676 clone = rq->special;
1677 atomic_inc(&md->pending[rq_data_dir(clone)]);
1678
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001679 spin_unlock(q->queue_lock);
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +00001680 map_request(ti, clone, md);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001681 spin_lock_irq(q->queue_lock);
1682 }
1683
1684 goto out;
1685
1686plug_and_out:
1687 if (!elv_queue_empty(q))
1688 /* Some requests still remain, retry later */
1689 blk_plug_device(q);
1690
1691out:
1692 dm_table_put(map);
1693
1694 return;
1695}
1696
1697int dm_underlying_device_busy(struct request_queue *q)
1698{
1699 return blk_lld_busy(q);
1700}
1701EXPORT_SYMBOL_GPL(dm_underlying_device_busy);
1702
1703static int dm_lld_busy(struct request_queue *q)
1704{
1705 int r;
1706 struct mapped_device *md = q->queuedata;
Alasdair G Kergon7c666412009-12-10 23:52:19 +00001707 struct dm_table *map = dm_get_live_table(md);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001708
1709 if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))
1710 r = 1;
1711 else
1712 r = dm_table_any_busy_target(map);
1713
1714 dm_table_put(map);
1715
1716 return r;
1717}
1718
Jens Axboe165125e2007-07-24 09:28:11 +02001719static void dm_unplug_all(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720{
1721 struct mapped_device *md = q->queuedata;
Alasdair G Kergon7c666412009-12-10 23:52:19 +00001722 struct dm_table *map = dm_get_live_table(md);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001723
1724 if (map) {
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001725 if (dm_request_based(md))
1726 generic_unplug_device(q);
1727
Linus Torvalds1da177e2005-04-16 15:20:36 -07001728 dm_table_unplug_all(map);
1729 dm_table_put(map);
1730 }
1731}
1732
1733static int dm_any_congested(void *congested_data, int bdi_bits)
1734{
Chandra Seetharaman8a57dfc2008-11-13 23:39:14 +00001735 int r = bdi_bits;
1736 struct mapped_device *md = congested_data;
1737 struct dm_table *map;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738
Alasdair G Kergon1eb787e2009-04-09 00:27:14 +01001739 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
Alasdair G Kergon7c666412009-12-10 23:52:19 +00001740 map = dm_get_live_table(md);
Chandra Seetharaman8a57dfc2008-11-13 23:39:14 +00001741 if (map) {
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01001742 /*
1743 * Request-based dm cares about only own queue for
1744 * the query about congestion status of request_queue
1745 */
1746 if (dm_request_based(md))
1747 r = md->queue->backing_dev_info.state &
1748 bdi_bits;
1749 else
1750 r = dm_table_any_congested(map, bdi_bits);
1751
Chandra Seetharaman8a57dfc2008-11-13 23:39:14 +00001752 dm_table_put(map);
1753 }
1754 }
1755
Linus Torvalds1da177e2005-04-16 15:20:36 -07001756 return r;
1757}
1758
1759/*-----------------------------------------------------------------
1760 * An IDR is used to keep track of allocated minor numbers.
1761 *---------------------------------------------------------------*/
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762static DEFINE_IDR(_minor_idr);
1763
Alasdair G Kergon2b06cff2006-06-26 00:27:32 -07001764static void free_minor(int minor)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765{
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07001766 spin_lock(&_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001767 idr_remove(&_minor_idr, minor);
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07001768 spin_unlock(&_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001769}
1770
1771/*
1772 * See if the device with a specific minor # is free.
1773 */
Frederik Deweerdtcf13ab82008-04-24 22:10:59 +01001774static int specific_minor(int minor)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001775{
1776 int r, m;
1777
1778 if (minor >= (1 << MINORBITS))
1779 return -EINVAL;
1780
Jeff Mahoney62f75c22006-06-26 00:27:21 -07001781 r = idr_pre_get(&_minor_idr, GFP_KERNEL);
1782 if (!r)
1783 return -ENOMEM;
1784
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07001785 spin_lock(&_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786
1787 if (idr_find(&_minor_idr, minor)) {
1788 r = -EBUSY;
1789 goto out;
1790 }
1791
Jeff Mahoneyba61fdd2006-06-26 00:27:21 -07001792 r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m);
Jeff Mahoney62f75c22006-06-26 00:27:21 -07001793 if (r)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795
1796 if (m != minor) {
1797 idr_remove(&_minor_idr, m);
1798 r = -EBUSY;
1799 goto out;
1800 }
1801
1802out:
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07001803 spin_unlock(&_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804 return r;
1805}
1806
Frederik Deweerdtcf13ab82008-04-24 22:10:59 +01001807static int next_free_minor(int *minor)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001808{
Alasdair G Kergon2b06cff2006-06-26 00:27:32 -07001809 int r, m;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810
Linus Torvalds1da177e2005-04-16 15:20:36 -07001811 r = idr_pre_get(&_minor_idr, GFP_KERNEL);
Jeff Mahoney62f75c22006-06-26 00:27:21 -07001812 if (!r)
1813 return -ENOMEM;
1814
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07001815 spin_lock(&_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001816
Jeff Mahoneyba61fdd2006-06-26 00:27:21 -07001817 r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m);
Frederik Deweerdtcf13ab82008-04-24 22:10:59 +01001818 if (r)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001819 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001820
1821 if (m >= (1 << MINORBITS)) {
1822 idr_remove(&_minor_idr, m);
1823 r = -ENOSPC;
1824 goto out;
1825 }
1826
1827 *minor = m;
1828
1829out:
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07001830 spin_unlock(&_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001831 return r;
1832}
1833
Alexey Dobriyan83d5cde2009-09-21 17:01:13 -07001834static const struct block_device_operations dm_blk_dops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001835
Mikulas Patocka53d59142009-04-02 19:55:37 +01001836static void dm_wq_work(struct work_struct *work);
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001837static void dm_rq_barrier_work(struct work_struct *work);
Mikulas Patocka53d59142009-04-02 19:55:37 +01001838
Linus Torvalds1da177e2005-04-16 15:20:36 -07001839/*
1840 * Allocate and initialise a blank device with a given minor.
1841 */
Alasdair G Kergon2b06cff2006-06-26 00:27:32 -07001842static struct mapped_device *alloc_dev(int minor)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001843{
1844 int r;
Frederik Deweerdtcf13ab82008-04-24 22:10:59 +01001845 struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL);
Jeff Mahoneyba61fdd2006-06-26 00:27:21 -07001846 void *old_md;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001847
1848 if (!md) {
1849 DMWARN("unable to allocate device, out of memory.");
1850 return NULL;
1851 }
1852
Jeff Mahoney10da4f72006-06-26 00:27:25 -07001853 if (!try_module_get(THIS_MODULE))
Milan Broz6ed7ade2008-02-08 02:10:19 +00001854 goto bad_module_get;
Jeff Mahoney10da4f72006-06-26 00:27:25 -07001855
Linus Torvalds1da177e2005-04-16 15:20:36 -07001856 /* get a minor number for the dev */
Alasdair G Kergon2b06cff2006-06-26 00:27:32 -07001857 if (minor == DM_ANY_MINOR)
Frederik Deweerdtcf13ab82008-04-24 22:10:59 +01001858 r = next_free_minor(&minor);
Alasdair G Kergon2b06cff2006-06-26 00:27:32 -07001859 else
Frederik Deweerdtcf13ab82008-04-24 22:10:59 +01001860 r = specific_minor(minor);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001861 if (r < 0)
Milan Broz6ed7ade2008-02-08 02:10:19 +00001862 goto bad_minor;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001863
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07001864 init_rwsem(&md->io_lock);
Daniel Walkere61290a2008-02-08 02:10:08 +00001865 mutex_init(&md->suspend_lock);
Mikulas Patocka022c2612009-04-02 19:55:39 +01001866 spin_lock_init(&md->deferred_lock);
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001867 spin_lock_init(&md->barrier_error_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868 rwlock_init(&md->map_lock);
1869 atomic_set(&md->holders, 1);
Alasdair G Kergon5c6bd752006-06-26 00:27:34 -07001870 atomic_set(&md->open_count, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001871 atomic_set(&md->event_nr, 0);
Mike Anderson7a8c3d32007-10-19 22:48:01 +01001872 atomic_set(&md->uevent_seq, 0);
1873 INIT_LIST_HEAD(&md->uevent_list);
1874 spin_lock_init(&md->uevent_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001875
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001876 md->queue = blk_init_queue(dm_request_fn, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001877 if (!md->queue)
Milan Broz6ed7ade2008-02-08 02:10:19 +00001878 goto bad_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001880 /*
1881 * Request-based dm devices cannot be stacked on top of bio-based dm
1882 * devices. The type of this dm device has not been decided yet,
1883 * although we initialized the queue using blk_init_queue().
1884 * The type is decided at the first table loading time.
1885 * To prevent problematic device stacking, clear the queue flag
1886 * for request stacking support until then.
1887 *
1888 * This queue is new, so no concurrency on the queue_flags.
1889 */
1890 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
1891 md->saved_make_request_fn = md->queue->make_request_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892 md->queue->queuedata = md;
1893 md->queue->backing_dev_info.congested_fn = dm_any_congested;
1894 md->queue->backing_dev_info.congested_data = md;
1895 blk_queue_make_request(md->queue, dm_request);
Jens Axboedaef2652006-01-10 10:48:02 +01001896 blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001897 md->queue->unplug_fn = dm_unplug_all;
Milan Brozf6fccb12008-07-21 12:00:37 +01001898 blk_queue_merge_bvec(md->queue, dm_merge_bvec);
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001899 blk_queue_softirq_done(md->queue, dm_softirq_done);
1900 blk_queue_prep_rq(md->queue, dm_prep_fn);
1901 blk_queue_lld_busy(md->queue, dm_lld_busy);
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001902 blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN_FLUSH,
1903 dm_rq_prepare_flush);
Stefan Bader9faf4002006-10-03 01:15:41 -07001904
Linus Torvalds1da177e2005-04-16 15:20:36 -07001905 md->disk = alloc_disk(1);
1906 if (!md->disk)
Milan Broz6ed7ade2008-02-08 02:10:19 +00001907 goto bad_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001908
Nikanth Karthikesan316d3152009-10-06 20:16:55 +02001909 atomic_set(&md->pending[0], 0);
1910 atomic_set(&md->pending[1], 0);
Jeff Mahoneyf0b04112006-06-26 00:27:25 -07001911 init_waitqueue_head(&md->wait);
Mikulas Patocka53d59142009-04-02 19:55:37 +01001912 INIT_WORK(&md->work, dm_wq_work);
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00001913 INIT_WORK(&md->barrier_work, dm_rq_barrier_work);
Jeff Mahoneyf0b04112006-06-26 00:27:25 -07001914 init_waitqueue_head(&md->eventq);
1915
Linus Torvalds1da177e2005-04-16 15:20:36 -07001916 md->disk->major = _major;
1917 md->disk->first_minor = minor;
1918 md->disk->fops = &dm_blk_dops;
1919 md->disk->queue = md->queue;
1920 md->disk->private_data = md;
1921 sprintf(md->disk->disk_name, "dm-%d", minor);
1922 add_disk(md->disk);
Mike Anderson7e51f252006-03-27 01:17:52 -08001923 format_dev_t(md->name, MKDEV(_major, minor));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001924
Milan Broz304f3f62008-02-08 02:11:17 +00001925 md->wq = create_singlethread_workqueue("kdmflush");
1926 if (!md->wq)
1927 goto bad_thread;
1928
Mikulas Patocka32a926d2009-06-22 10:12:17 +01001929 md->bdev = bdget_disk(md->disk, 0);
1930 if (!md->bdev)
1931 goto bad_bdev;
1932
Jeff Mahoneyba61fdd2006-06-26 00:27:21 -07001933 /* Populate the mapping, nobody knows we exist yet */
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07001934 spin_lock(&_minor_lock);
Jeff Mahoneyba61fdd2006-06-26 00:27:21 -07001935 old_md = idr_replace(&_minor_idr, md, minor);
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07001936 spin_unlock(&_minor_lock);
Jeff Mahoneyba61fdd2006-06-26 00:27:21 -07001937
1938 BUG_ON(old_md != MINOR_ALLOCED);
1939
Linus Torvalds1da177e2005-04-16 15:20:36 -07001940 return md;
1941
Mikulas Patocka32a926d2009-06-22 10:12:17 +01001942bad_bdev:
1943 destroy_workqueue(md->wq);
Milan Broz304f3f62008-02-08 02:11:17 +00001944bad_thread:
Zdenek Kabelac03022c52009-10-16 23:18:15 +01001945 del_gendisk(md->disk);
Milan Broz304f3f62008-02-08 02:11:17 +00001946 put_disk(md->disk);
Milan Broz6ed7ade2008-02-08 02:10:19 +00001947bad_disk:
Al Viro1312f402006-03-12 11:02:03 -05001948 blk_cleanup_queue(md->queue);
Milan Broz6ed7ade2008-02-08 02:10:19 +00001949bad_queue:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001950 free_minor(minor);
Milan Broz6ed7ade2008-02-08 02:10:19 +00001951bad_minor:
Jeff Mahoney10da4f72006-06-26 00:27:25 -07001952 module_put(THIS_MODULE);
Milan Broz6ed7ade2008-02-08 02:10:19 +00001953bad_module_get:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001954 kfree(md);
1955 return NULL;
1956}
1957
Jun'ichi Nomuraae9da832007-10-19 22:38:43 +01001958static void unlock_fs(struct mapped_device *md);
1959
Linus Torvalds1da177e2005-04-16 15:20:36 -07001960static void free_dev(struct mapped_device *md)
1961{
Tejun Heof331c022008-09-03 09:01:48 +02001962 int minor = MINOR(disk_devt(md->disk));
Jun'ichi Nomura63d94e42006-02-24 13:04:25 -08001963
Mikulas Patocka32a926d2009-06-22 10:12:17 +01001964 unlock_fs(md);
1965 bdput(md->bdev);
Milan Broz304f3f62008-02-08 02:11:17 +00001966 destroy_workqueue(md->wq);
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001967 if (md->tio_pool)
1968 mempool_destroy(md->tio_pool);
1969 if (md->io_pool)
1970 mempool_destroy(md->io_pool);
1971 if (md->bs)
1972 bioset_free(md->bs);
Martin K. Petersen9c470082009-04-09 00:27:12 +01001973 blk_integrity_unregister(md->disk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001974 del_gendisk(md->disk);
Jun'ichi Nomura63d94e42006-02-24 13:04:25 -08001975 free_minor(minor);
Jeff Mahoneyfba9f902006-06-26 00:27:23 -07001976
1977 spin_lock(&_minor_lock);
1978 md->disk->private_data = NULL;
1979 spin_unlock(&_minor_lock);
1980
Linus Torvalds1da177e2005-04-16 15:20:36 -07001981 put_disk(md->disk);
Al Viro1312f402006-03-12 11:02:03 -05001982 blk_cleanup_queue(md->queue);
Jeff Mahoney10da4f72006-06-26 00:27:25 -07001983 module_put(THIS_MODULE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001984 kfree(md);
1985}
1986
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01001987static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
1988{
1989 struct dm_md_mempools *p;
1990
1991 if (md->io_pool && md->tio_pool && md->bs)
1992 /* the md already has necessary mempools */
1993 goto out;
1994
1995 p = dm_table_get_md_mempools(t);
1996 BUG_ON(!p || md->io_pool || md->tio_pool || md->bs);
1997
1998 md->io_pool = p->io_pool;
1999 p->io_pool = NULL;
2000 md->tio_pool = p->tio_pool;
2001 p->tio_pool = NULL;
2002 md->bs = p->bs;
2003 p->bs = NULL;
2004
2005out:
2006 /* mempool bind completed, now no need any mempools in the table */
2007 dm_table_free_md_mempools(t);
2008}
2009
Linus Torvalds1da177e2005-04-16 15:20:36 -07002010/*
2011 * Bind a table to the device.
2012 */
2013static void event_callback(void *context)
2014{
Mike Anderson7a8c3d32007-10-19 22:48:01 +01002015 unsigned long flags;
2016 LIST_HEAD(uevents);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002017 struct mapped_device *md = (struct mapped_device *) context;
2018
Mike Anderson7a8c3d32007-10-19 22:48:01 +01002019 spin_lock_irqsave(&md->uevent_lock, flags);
2020 list_splice_init(&md->uevent_list, &uevents);
2021 spin_unlock_irqrestore(&md->uevent_lock, flags);
2022
Tejun Heoed9e1982008-08-25 19:56:05 +09002023 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
Mike Anderson7a8c3d32007-10-19 22:48:01 +01002024
Linus Torvalds1da177e2005-04-16 15:20:36 -07002025 atomic_inc(&md->event_nr);
2026 wake_up(&md->eventq);
2027}
2028
Alasdair G Kergon4e901882005-07-28 21:15:59 -07002029static void __set_size(struct mapped_device *md, sector_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002030{
Alasdair G Kergon4e901882005-07-28 21:15:59 -07002031 set_capacity(md->disk, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002032
Mikulas Patockadb8fef42009-06-22 10:12:15 +01002033 mutex_lock(&md->bdev->bd_inode->i_mutex);
2034 i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
2035 mutex_unlock(&md->bdev->bd_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002036}
2037
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002038/*
2039 * Returns old map, which caller must destroy.
2040 */
2041static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
2042 struct queue_limits *limits)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002043{
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002044 struct dm_table *old_map;
Jens Axboe165125e2007-07-24 09:28:11 +02002045 struct request_queue *q = md->queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046 sector_t size;
Kiyoshi Ueda523d9292009-06-22 10:12:37 +01002047 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002048
2049 size = dm_table_get_size(t);
Darrick J. Wong3ac51e72006-03-27 01:17:54 -08002050
2051 /*
2052 * Wipe any geometry if the size of the table changed.
2053 */
2054 if (size != get_capacity(md->disk))
2055 memset(&md->geometry, 0, sizeof(md->geometry));
2056
Mikulas Patocka32a926d2009-06-22 10:12:17 +01002057 __set_size(md, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002058
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002059 dm_table_event_callback(t, event_callback, md);
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002060
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01002061 /*
2062 * The queue hasn't been stopped yet, if the old table type wasn't
2063 * for request-based during suspension. So stop it to prevent
2064 * I/O mapping before resume.
2065 * This must be done before setting the queue restrictions,
2066 * because request-based dm may be run just after the setting.
2067 */
2068 if (dm_table_request_based(t) && !blk_queue_stopped(q))
2069 stop_queue(q);
2070
2071 __bind_mempools(md, t);
2072
Kiyoshi Ueda523d9292009-06-22 10:12:37 +01002073 write_lock_irqsave(&md->map_lock, flags);
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002074 old_map = md->map;
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002075 md->map = t;
Mike Snitzer754c5fc2009-06-22 10:12:34 +01002076 dm_table_set_restrictions(t, q, limits);
Kiyoshi Ueda523d9292009-06-22 10:12:37 +01002077 write_unlock_irqrestore(&md->map_lock, flags);
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002078
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002079 return old_map;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002080}
2081
Alasdair G Kergona7940152009-12-10 23:52:23 +00002082/*
2083 * Returns unbound table for the caller to free.
2084 */
2085static struct dm_table *__unbind(struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002086{
2087 struct dm_table *map = md->map;
Kiyoshi Ueda523d9292009-06-22 10:12:37 +01002088 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002089
2090 if (!map)
Alasdair G Kergona7940152009-12-10 23:52:23 +00002091 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002092
2093 dm_table_event_callback(map, NULL, NULL);
Kiyoshi Ueda523d9292009-06-22 10:12:37 +01002094 write_lock_irqsave(&md->map_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002095 md->map = NULL;
Kiyoshi Ueda523d9292009-06-22 10:12:37 +01002096 write_unlock_irqrestore(&md->map_lock, flags);
Alasdair G Kergona7940152009-12-10 23:52:23 +00002097
2098 return map;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002099}
2100
2101/*
2102 * Constructor for a new device.
2103 */
Alasdair G Kergon2b06cff2006-06-26 00:27:32 -07002104int dm_create(int minor, struct mapped_device **result)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002105{
2106 struct mapped_device *md;
2107
Alasdair G Kergon2b06cff2006-06-26 00:27:32 -07002108 md = alloc_dev(minor);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109 if (!md)
2110 return -ENXIO;
2111
Milan Broz784aae72009-01-06 03:05:12 +00002112 dm_sysfs_init(md);
2113
Linus Torvalds1da177e2005-04-16 15:20:36 -07002114 *result = md;
2115 return 0;
2116}
2117
David Teigland637842c2006-01-06 00:20:00 -08002118static struct mapped_device *dm_find_md(dev_t dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002119{
2120 struct mapped_device *md;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002121 unsigned minor = MINOR(dev);
2122
2123 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2124 return NULL;
2125
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07002126 spin_lock(&_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002127
2128 md = idr_find(&_minor_idr, minor);
Jeff Mahoneyfba9f902006-06-26 00:27:23 -07002129 if (md && (md == MINOR_ALLOCED ||
Tejun Heof331c022008-09-03 09:01:48 +02002130 (MINOR(disk_devt(dm_disk(md))) != minor) ||
Alasdair G Kergon17b2f662006-06-26 00:27:33 -07002131 test_bit(DMF_FREEING, &md->flags))) {
David Teigland637842c2006-01-06 00:20:00 -08002132 md = NULL;
Jeff Mahoneyfba9f902006-06-26 00:27:23 -07002133 goto out;
2134 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135
Jeff Mahoneyfba9f902006-06-26 00:27:23 -07002136out:
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07002137 spin_unlock(&_minor_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002138
David Teigland637842c2006-01-06 00:20:00 -08002139 return md;
2140}
2141
David Teiglandd229a952006-01-06 00:20:01 -08002142struct mapped_device *dm_get_md(dev_t dev)
2143{
2144 struct mapped_device *md = dm_find_md(dev);
2145
2146 if (md)
2147 dm_get(md);
2148
2149 return md;
2150}
2151
Alasdair G Kergon9ade92a2006-03-27 01:17:53 -08002152void *dm_get_mdptr(struct mapped_device *md)
David Teigland637842c2006-01-06 00:20:00 -08002153{
Alasdair G Kergon9ade92a2006-03-27 01:17:53 -08002154 return md->interface_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002155}
2156
2157void dm_set_mdptr(struct mapped_device *md, void *ptr)
2158{
2159 md->interface_ptr = ptr;
2160}
2161
2162void dm_get(struct mapped_device *md)
2163{
2164 atomic_inc(&md->holders);
2165}
2166
Alasdair G Kergon72d94862006-06-26 00:27:35 -07002167const char *dm_device_name(struct mapped_device *md)
2168{
2169 return md->name;
2170}
2171EXPORT_SYMBOL_GPL(dm_device_name);
2172
Linus Torvalds1da177e2005-04-16 15:20:36 -07002173void dm_put(struct mapped_device *md)
2174{
Mike Anderson1134e5a2006-03-27 01:17:54 -08002175 struct dm_table *map;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002176
Jeff Mahoneyfba9f902006-06-26 00:27:23 -07002177 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2178
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07002179 if (atomic_dec_and_lock(&md->holders, &_minor_lock)) {
Alasdair G Kergon7c666412009-12-10 23:52:19 +00002180 map = dm_get_live_table(md);
Tejun Heof331c022008-09-03 09:01:48 +02002181 idr_replace(&_minor_idr, MINOR_ALLOCED,
2182 MINOR(disk_devt(dm_disk(md))));
Jeff Mahoneyfba9f902006-06-26 00:27:23 -07002183 set_bit(DMF_FREEING, &md->flags);
Jeff Mahoneyf32c10b2006-06-26 00:27:22 -07002184 spin_unlock(&_minor_lock);
Kiyoshi Ueda4f186f82009-12-10 23:52:26 +00002185 if (!dm_suspended_md(md)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002186 dm_table_presuspend_targets(map);
2187 dm_table_postsuspend_targets(map);
2188 }
Milan Broz784aae72009-01-06 03:05:12 +00002189 dm_sysfs_exit(md);
Mike Anderson1134e5a2006-03-27 01:17:54 -08002190 dm_table_put(map);
Alasdair G Kergona7940152009-12-10 23:52:23 +00002191 dm_table_destroy(__unbind(md));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002192 free_dev(md);
2193 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002194}
Edward Goggin79eb8852007-05-09 02:32:56 -07002195EXPORT_SYMBOL_GPL(dm_put);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002196
Mikulas Patocka401600d2009-04-02 19:55:38 +01002197static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
Milan Broz46125c12008-02-08 02:10:30 +00002198{
2199 int r = 0;
Mikulas Patockab44ebeb2009-04-02 19:55:39 +01002200 DECLARE_WAITQUEUE(wait, current);
2201
2202 dm_unplug_all(md->queue);
2203
2204 add_wait_queue(&md->wait, &wait);
Milan Broz46125c12008-02-08 02:10:30 +00002205
2206 while (1) {
Mikulas Patocka401600d2009-04-02 19:55:38 +01002207 set_current_state(interruptible);
Milan Broz46125c12008-02-08 02:10:30 +00002208
2209 smp_mb();
Kiyoshi Uedab4324fe2009-12-10 23:52:16 +00002210 if (!md_in_flight(md))
Milan Broz46125c12008-02-08 02:10:30 +00002211 break;
2212
Mikulas Patocka401600d2009-04-02 19:55:38 +01002213 if (interruptible == TASK_INTERRUPTIBLE &&
2214 signal_pending(current)) {
Milan Broz46125c12008-02-08 02:10:30 +00002215 r = -EINTR;
2216 break;
2217 }
2218
2219 io_schedule();
2220 }
2221 set_current_state(TASK_RUNNING);
2222
Mikulas Patockab44ebeb2009-04-02 19:55:39 +01002223 remove_wait_queue(&md->wait, &wait);
2224
Milan Broz46125c12008-02-08 02:10:30 +00002225 return r;
2226}
2227
Mikulas Patocka531fe962009-06-22 10:12:17 +01002228static void dm_flush(struct mapped_device *md)
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01002229{
2230 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
Mikulas Patocka52b1fd52009-06-22 10:12:21 +01002231
2232 bio_init(&md->barrier_bio);
2233 md->barrier_bio.bi_bdev = md->bdev;
2234 md->barrier_bio.bi_rw = WRITE_BARRIER;
2235 __split_and_process_bio(md, &md->barrier_bio);
2236
2237 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01002238}
2239
2240static void process_barrier(struct mapped_device *md, struct bio *bio)
2241{
Mikulas Patocka5aa27812009-06-22 10:12:18 +01002242 md->barrier_error = 0;
2243
Mikulas Patocka531fe962009-06-22 10:12:17 +01002244 dm_flush(md);
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01002245
Mikulas Patocka5aa27812009-06-22 10:12:18 +01002246 if (!bio_empty_barrier(bio)) {
2247 __split_and_process_bio(md, bio);
2248 dm_flush(md);
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01002249 }
2250
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01002251 if (md->barrier_error != DM_ENDIO_REQUEUE)
Mikulas Patocka531fe962009-06-22 10:12:17 +01002252 bio_endio(bio, md->barrier_error);
Mikulas Patocka2761e952009-06-22 10:12:18 +01002253 else {
2254 spin_lock_irq(&md->deferred_lock);
2255 bio_list_add_head(&md->deferred, bio);
2256 spin_unlock_irq(&md->deferred_lock);
2257 }
Mikulas Patockaaf7e4662009-04-09 00:27:16 +01002258}
2259
Linus Torvalds1da177e2005-04-16 15:20:36 -07002260/*
2261 * Process the deferred bios
2262 */
Mikulas Patockaef208582009-04-02 19:55:38 +01002263static void dm_wq_work(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002264{
Mikulas Patockaef208582009-04-02 19:55:38 +01002265 struct mapped_device *md = container_of(work, struct mapped_device,
2266 work);
Milan Broz6d6f10d2008-02-08 02:10:22 +00002267 struct bio *c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002268
Mikulas Patockaef208582009-04-02 19:55:38 +01002269 down_write(&md->io_lock);
2270
Mikulas Patocka3b00b202009-04-09 00:27:15 +01002271 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
Alasdair G Kergondf12ee92009-04-09 00:27:13 +01002272 spin_lock_irq(&md->deferred_lock);
2273 c = bio_list_pop(&md->deferred);
2274 spin_unlock_irq(&md->deferred_lock);
Mikulas Patocka022c2612009-04-02 19:55:39 +01002275
Alasdair G Kergondf12ee92009-04-09 00:27:13 +01002276 if (!c) {
Alasdair G Kergon1eb787e2009-04-09 00:27:14 +01002277 clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
Alasdair G Kergondf12ee92009-04-09 00:27:13 +01002278 break;
2279 }
2280
Mikulas Patocka3b00b202009-04-09 00:27:15 +01002281 up_write(&md->io_lock);
2282
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01002283 if (dm_request_based(md))
2284 generic_make_request(c);
2285 else {
Jens Axboe1f98a132009-09-11 14:32:04 +02002286 if (bio_rw_flagged(c, BIO_RW_BARRIER))
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01002287 process_barrier(md, c);
2288 else
2289 __split_and_process_bio(md, c);
2290 }
Mikulas Patocka3b00b202009-04-09 00:27:15 +01002291
2292 down_write(&md->io_lock);
Mikulas Patocka022c2612009-04-02 19:55:39 +01002293 }
Milan Broz73d410c2008-02-08 02:10:25 +00002294
Mikulas Patockaef208582009-04-02 19:55:38 +01002295 up_write(&md->io_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002296}
2297
Mikulas Patocka9a1fb462009-04-02 19:55:36 +01002298static void dm_queue_flush(struct mapped_device *md)
Milan Broz304f3f62008-02-08 02:11:17 +00002299{
Mikulas Patocka3b00b202009-04-09 00:27:15 +01002300 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2301 smp_mb__after_clear_bit();
Mikulas Patocka53d59142009-04-02 19:55:37 +01002302 queue_work(md->wq, &md->work);
Milan Broz304f3f62008-02-08 02:11:17 +00002303}
2304
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00002305static void dm_rq_set_flush_nr(struct request *clone, unsigned flush_nr)
2306{
2307 struct dm_rq_target_io *tio = clone->end_io_data;
2308
2309 tio->info.flush_request = flush_nr;
2310}
2311
2312/* Issue barrier requests to targets and wait for their completion. */
2313static int dm_rq_barrier(struct mapped_device *md)
2314{
2315 int i, j;
Alasdair G Kergon7c666412009-12-10 23:52:19 +00002316 struct dm_table *map = dm_get_live_table(md);
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00002317 unsigned num_targets = dm_table_get_num_targets(map);
2318 struct dm_target *ti;
2319 struct request *clone;
2320
2321 md->barrier_error = 0;
2322
2323 for (i = 0; i < num_targets; i++) {
2324 ti = dm_table_get_target(map, i);
2325 for (j = 0; j < ti->num_flush_requests; j++) {
2326 clone = clone_rq(md->flush_request, md, GFP_NOIO);
2327 dm_rq_set_flush_nr(clone, j);
2328 atomic_inc(&md->pending[rq_data_dir(clone)]);
2329 map_request(ti, clone, md);
2330 }
2331 }
2332
2333 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
2334 dm_table_put(map);
2335
2336 return md->barrier_error;
2337}
2338
2339static void dm_rq_barrier_work(struct work_struct *work)
2340{
2341 int error;
2342 struct mapped_device *md = container_of(work, struct mapped_device,
2343 barrier_work);
2344 struct request_queue *q = md->queue;
2345 struct request *rq;
2346 unsigned long flags;
2347
2348 /*
2349 * Hold the md reference here and leave it at the last part so that
2350 * the md can't be deleted by device opener when the barrier request
2351 * completes.
2352 */
2353 dm_get(md);
2354
2355 error = dm_rq_barrier(md);
2356
2357 rq = md->flush_request;
2358 md->flush_request = NULL;
2359
2360 if (error == DM_ENDIO_REQUEUE) {
2361 spin_lock_irqsave(q->queue_lock, flags);
2362 blk_requeue_request(q, rq);
2363 spin_unlock_irqrestore(q->queue_lock, flags);
2364 } else
2365 blk_end_request_all(rq, error);
2366
2367 blk_run_queue(q);
2368
2369 dm_put(md);
2370}
2371
Linus Torvalds1da177e2005-04-16 15:20:36 -07002372/*
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002373 * Swap in a new table, returning the old one for the caller to destroy.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002374 */
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002375struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002376{
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002377 struct dm_table *map = ERR_PTR(-EINVAL);
Mike Snitzer754c5fc2009-06-22 10:12:34 +01002378 struct queue_limits limits;
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002379 int r;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002380
Daniel Walkere61290a2008-02-08 02:10:08 +00002381 mutex_lock(&md->suspend_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002382
2383 /* device must be suspended */
Kiyoshi Ueda4f186f82009-12-10 23:52:26 +00002384 if (!dm_suspended_md(md))
Alasdair G Kergon93c534a2005-07-12 15:53:05 -07002385 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002386
Mike Snitzer754c5fc2009-06-22 10:12:34 +01002387 r = dm_calculate_queue_limits(table, &limits);
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002388 if (r) {
2389 map = ERR_PTR(r);
Mike Snitzer754c5fc2009-06-22 10:12:34 +01002390 goto out;
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002391 }
Mike Snitzer754c5fc2009-06-22 10:12:34 +01002392
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01002393 /* cannot change the device type, once a table is bound */
2394 if (md->map &&
2395 (dm_table_get_type(md->map) != dm_table_get_type(table))) {
2396 DMWARN("can't change the device type after a table is bound");
2397 goto out;
2398 }
2399
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002400 map = __bind(md, table, &limits);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002401
Alasdair G Kergon93c534a2005-07-12 15:53:05 -07002402out:
Daniel Walkere61290a2008-02-08 02:10:08 +00002403 mutex_unlock(&md->suspend_lock);
Alasdair G Kergon042d2a92009-12-10 23:52:24 +00002404 return map;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002405}
2406
2407/*
2408 * Functions to lock and unlock any filesystem running on the
2409 * device.
2410 */
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002411static int lock_fs(struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002412{
Alasdair G Kergone39e2e92006-01-06 00:20:05 -08002413 int r;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002414
2415 WARN_ON(md->frozen_sb);
Alasdair G Kergondfbe03f2005-05-05 16:16:04 -07002416
Mikulas Patockadb8fef42009-06-22 10:12:15 +01002417 md->frozen_sb = freeze_bdev(md->bdev);
Alasdair G Kergondfbe03f2005-05-05 16:16:04 -07002418 if (IS_ERR(md->frozen_sb)) {
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002419 r = PTR_ERR(md->frozen_sb);
Alasdair G Kergone39e2e92006-01-06 00:20:05 -08002420 md->frozen_sb = NULL;
2421 return r;
Alasdair G Kergondfbe03f2005-05-05 16:16:04 -07002422 }
2423
Alasdair G Kergonaa8d7c22006-01-06 00:20:06 -08002424 set_bit(DMF_FROZEN, &md->flags);
2425
Linus Torvalds1da177e2005-04-16 15:20:36 -07002426 return 0;
2427}
2428
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002429static void unlock_fs(struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002430{
Alasdair G Kergonaa8d7c22006-01-06 00:20:06 -08002431 if (!test_bit(DMF_FROZEN, &md->flags))
2432 return;
2433
Mikulas Patockadb8fef42009-06-22 10:12:15 +01002434 thaw_bdev(md->bdev, md->frozen_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002435 md->frozen_sb = NULL;
Alasdair G Kergonaa8d7c22006-01-06 00:20:06 -08002436 clear_bit(DMF_FROZEN, &md->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002437}
2438
2439/*
2440 * We need to be able to change a mapping table under a mounted
2441 * filesystem. For example we might want to move some data in
2442 * the background. Before the table can be swapped with
2443 * dm_bind_table, dm_suspend must be called to flush any in
2444 * flight bios and ensure that any further io gets deferred.
2445 */
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01002446/*
2447 * Suspend mechanism in request-based dm.
2448 *
Kiyoshi Ueda9f518b22009-12-10 23:52:16 +00002449 * 1. Flush all I/Os by lock_fs() if needed.
2450 * 2. Stop dispatching any I/O by stopping the request_queue.
2451 * 3. Wait for all in-flight I/Os to be completed or requeued.
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01002452 *
Kiyoshi Ueda9f518b22009-12-10 23:52:16 +00002453 * To abort suspend, start the request_queue.
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01002454 */
Kiyoshi Uedaa3d77d32006-12-08 02:41:04 -08002455int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002456{
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002457 struct dm_table *map = NULL;
Milan Broz46125c12008-02-08 02:10:30 +00002458 int r = 0;
Kiyoshi Uedaa3d77d32006-12-08 02:41:04 -08002459 int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -08002460 int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002461
Daniel Walkere61290a2008-02-08 02:10:08 +00002462 mutex_lock(&md->suspend_lock);
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002463
Kiyoshi Ueda4f186f82009-12-10 23:52:26 +00002464 if (dm_suspended_md(md)) {
Milan Broz73d410c2008-02-08 02:10:25 +00002465 r = -EINVAL;
Alasdair G Kergond2874832006-11-08 17:44:43 -08002466 goto out_unlock;
Milan Broz73d410c2008-02-08 02:10:25 +00002467 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002468
Alasdair G Kergon7c666412009-12-10 23:52:19 +00002469 map = dm_get_live_table(md);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002470
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -08002471 /*
2472 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2473 * This flag is cleared before dm_suspend returns.
2474 */
2475 if (noflush)
2476 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2477
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002478 /* This does not get reverted if there's an error later. */
2479 dm_table_presuspend_targets(map);
2480
Mikulas Patocka32a926d2009-06-22 10:12:17 +01002481 /*
Kiyoshi Ueda9f518b22009-12-10 23:52:16 +00002482 * Flush I/O to the device.
2483 * Any I/O submitted after lock_fs() may not be flushed.
2484 * noflush takes precedence over do_lockfs.
2485 * (lock_fs() flushes I/Os and waits for them to complete.)
Mikulas Patocka32a926d2009-06-22 10:12:17 +01002486 */
2487 if (!noflush && do_lockfs) {
2488 r = lock_fs(md);
2489 if (r)
Kiyoshi Uedaf431d962008-10-21 17:45:07 +01002490 goto out;
Alasdair G Kergonaa8d7c22006-01-06 00:20:06 -08002491 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002492
2493 /*
Mikulas Patocka3b00b202009-04-09 00:27:15 +01002494 * Here we must make sure that no processes are submitting requests
2495 * to target drivers i.e. no one may be executing
2496 * __split_and_process_bio. This is called from dm_request and
2497 * dm_wq_work.
2498 *
2499 * To get all processes out of __split_and_process_bio in dm_request,
2500 * we take the write lock. To prevent any process from reentering
2501 * __split_and_process_bio from dm_request, we set
2502 * DMF_QUEUE_IO_TO_THREAD.
2503 *
2504 * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND
2505 * and call flush_workqueue(md->wq). flush_workqueue will wait until
2506 * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any
2507 * further calls to __split_and_process_bio from dm_wq_work.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002508 */
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002509 down_write(&md->io_lock);
Alasdair G Kergon1eb787e2009-04-09 00:27:14 +01002510 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2511 set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002512 up_write(&md->io_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002513
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00002514 /*
2515 * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which
2516 * can be kicked until md->queue is stopped. So stop md->queue before
2517 * flushing md->wq.
2518 */
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01002519 if (dm_request_based(md))
Kiyoshi Ueda9f518b22009-12-10 23:52:16 +00002520 stop_queue(md->queue);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01002521
Kiyoshi Uedad0bcb872009-12-10 23:52:18 +00002522 flush_workqueue(md->wq);
2523
Linus Torvalds1da177e2005-04-16 15:20:36 -07002524 /*
Mikulas Patocka3b00b202009-04-09 00:27:15 +01002525 * At this point no more requests are entering target request routines.
2526 * We call dm_wait_for_completion to wait for all existing requests
2527 * to finish.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002528 */
Mikulas Patocka401600d2009-04-02 19:55:38 +01002529 r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002530
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002531 down_write(&md->io_lock);
Milan Broz6d6f10d2008-02-08 02:10:22 +00002532 if (noflush)
Mikulas Patocka022c2612009-04-02 19:55:39 +01002533 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
Milan Broz94d63512008-02-08 02:10:27 +00002534 up_write(&md->io_lock);
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -08002535
Linus Torvalds1da177e2005-04-16 15:20:36 -07002536 /* were we interrupted ? */
Milan Broz46125c12008-02-08 02:10:30 +00002537 if (r < 0) {
Mikulas Patocka9a1fb462009-04-02 19:55:36 +01002538 dm_queue_flush(md);
Milan Broz73d410c2008-02-08 02:10:25 +00002539
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01002540 if (dm_request_based(md))
Kiyoshi Ueda9f518b22009-12-10 23:52:16 +00002541 start_queue(md->queue);
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01002542
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002543 unlock_fs(md);
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -08002544 goto out; /* pushback list is already flushed, so skip flush */
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002545 }
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002546
Mikulas Patocka3b00b202009-04-09 00:27:15 +01002547 /*
2548 * If dm_wait_for_completion returned 0, the device is completely
2549 * quiescent now. There is no request-processing activity. All new
2550 * requests are being added to md->deferred list.
2551 */
2552
Linus Torvalds1da177e2005-04-16 15:20:36 -07002553 set_bit(DMF_SUSPENDED, &md->flags);
2554
Kiyoshi Ueda4d4471c2009-12-10 23:52:26 +00002555 dm_table_postsuspend_targets(map);
2556
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002557out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002558 dm_table_put(map);
Alasdair G Kergond2874832006-11-08 17:44:43 -08002559
2560out_unlock:
Daniel Walkere61290a2008-02-08 02:10:08 +00002561 mutex_unlock(&md->suspend_lock);
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002562 return r;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002563}
2564
2565int dm_resume(struct mapped_device *md)
2566{
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002567 int r = -EINVAL;
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002568 struct dm_table *map = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002569
Daniel Walkere61290a2008-02-08 02:10:08 +00002570 mutex_lock(&md->suspend_lock);
Kiyoshi Ueda4f186f82009-12-10 23:52:26 +00002571 if (!dm_suspended_md(md))
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002572 goto out;
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002573
Alasdair G Kergon7c666412009-12-10 23:52:19 +00002574 map = dm_get_live_table(md);
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002575 if (!map || !dm_table_get_size(map))
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002576 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002577
Milan Broz8757b772006-10-03 01:15:36 -07002578 r = dm_table_resume_targets(map);
2579 if (r)
2580 goto out;
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002581
Mikulas Patocka9a1fb462009-04-02 19:55:36 +01002582 dm_queue_flush(md);
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002583
Kiyoshi Uedacec47e32009-06-22 10:12:35 +01002584 /*
2585 * Flushing deferred I/Os must be done after targets are resumed
2586 * so that mapping of targets can work correctly.
2587 * Request-based dm is queueing the deferred I/Os in its request_queue.
2588 */
2589 if (dm_request_based(md))
2590 start_queue(md->queue);
2591
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002592 unlock_fs(md);
2593
2594 clear_bit(DMF_SUSPENDED, &md->flags);
2595
Linus Torvalds1da177e2005-04-16 15:20:36 -07002596 dm_table_unplug_all(map);
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002597 r = 0;
2598out:
2599 dm_table_put(map);
Daniel Walkere61290a2008-02-08 02:10:08 +00002600 mutex_unlock(&md->suspend_lock);
Alasdair G Kergon2ca33102005-07-28 21:16:00 -07002601
Alasdair G Kergoncf222b32005-07-28 21:15:57 -07002602 return r;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002603}
2604
2605/*-----------------------------------------------------------------
2606 * Event notification.
2607 *---------------------------------------------------------------*/
Milan Broz60935eb2009-06-22 10:12:30 +01002608void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
2609 unsigned cookie)
Alasdair G Kergon69267a32007-12-13 14:15:57 +00002610{
Milan Broz60935eb2009-06-22 10:12:30 +01002611 char udev_cookie[DM_COOKIE_LENGTH];
2612 char *envp[] = { udev_cookie, NULL };
2613
2614 if (!cookie)
2615 kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
2616 else {
2617 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
2618 DM_COOKIE_ENV_VAR_NAME, cookie);
2619 kobject_uevent_env(&disk_to_dev(md->disk)->kobj, action, envp);
2620 }
Alasdair G Kergon69267a32007-12-13 14:15:57 +00002621}
2622
Mike Anderson7a8c3d32007-10-19 22:48:01 +01002623uint32_t dm_next_uevent_seq(struct mapped_device *md)
2624{
2625 return atomic_add_return(1, &md->uevent_seq);
2626}
2627
Linus Torvalds1da177e2005-04-16 15:20:36 -07002628uint32_t dm_get_event_nr(struct mapped_device *md)
2629{
2630 return atomic_read(&md->event_nr);
2631}
2632
2633int dm_wait_event(struct mapped_device *md, int event_nr)
2634{
2635 return wait_event_interruptible(md->eventq,
2636 (event_nr != atomic_read(&md->event_nr)));
2637}
2638
Mike Anderson7a8c3d32007-10-19 22:48:01 +01002639void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
2640{
2641 unsigned long flags;
2642
2643 spin_lock_irqsave(&md->uevent_lock, flags);
2644 list_add(elist, &md->uevent_list);
2645 spin_unlock_irqrestore(&md->uevent_lock, flags);
2646}
2647
Linus Torvalds1da177e2005-04-16 15:20:36 -07002648/*
2649 * The gendisk is only valid as long as you have a reference
2650 * count on 'md'.
2651 */
2652struct gendisk *dm_disk(struct mapped_device *md)
2653{
2654 return md->disk;
2655}
2656
Milan Broz784aae72009-01-06 03:05:12 +00002657struct kobject *dm_kobject(struct mapped_device *md)
2658{
2659 return &md->kobj;
2660}
2661
2662/*
2663 * struct mapped_device should not be exported outside of dm.c
2664 * so use this check to verify that kobj is part of md structure
2665 */
2666struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
2667{
2668 struct mapped_device *md;
2669
2670 md = container_of(kobj, struct mapped_device, kobj);
2671 if (&md->kobj != kobj)
2672 return NULL;
2673
Milan Broz4d89b7b2009-06-22 10:12:11 +01002674 if (test_bit(DMF_FREEING, &md->flags) ||
Mike Anderson432a2122009-12-10 23:52:20 +00002675 dm_deleting_md(md))
Milan Broz4d89b7b2009-06-22 10:12:11 +01002676 return NULL;
2677
Milan Broz784aae72009-01-06 03:05:12 +00002678 dm_get(md);
2679 return md;
2680}
2681
Kiyoshi Ueda4f186f82009-12-10 23:52:26 +00002682int dm_suspended_md(struct mapped_device *md)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002683{
2684 return test_bit(DMF_SUSPENDED, &md->flags);
2685}
2686
Kiyoshi Ueda64dbce52009-12-10 23:52:27 +00002687int dm_suspended(struct dm_target *ti)
2688{
2689 struct mapped_device *md = dm_table_get_md(ti->table);
2690 int r = dm_suspended_md(md);
2691
2692 dm_put(md);
2693
2694 return r;
2695}
2696EXPORT_SYMBOL_GPL(dm_suspended);
2697
Kiyoshi Ueda2e93ccc2006-12-08 02:41:09 -08002698int dm_noflush_suspending(struct dm_target *ti)
2699{
2700 struct mapped_device *md = dm_table_get_md(ti->table);
2701 int r = __noflush_suspending(md);
2702
2703 dm_put(md);
2704
2705 return r;
2706}
2707EXPORT_SYMBOL_GPL(dm_noflush_suspending);
2708
Kiyoshi Uedae6ee8c02009-06-22 10:12:36 +01002709struct dm_md_mempools *dm_alloc_md_mempools(unsigned type)
2710{
2711 struct dm_md_mempools *pools = kmalloc(sizeof(*pools), GFP_KERNEL);
2712
2713 if (!pools)
2714 return NULL;
2715
2716 pools->io_pool = (type == DM_TYPE_BIO_BASED) ?
2717 mempool_create_slab_pool(MIN_IOS, _io_cache) :
2718 mempool_create_slab_pool(MIN_IOS, _rq_bio_info_cache);
2719 if (!pools->io_pool)
2720 goto free_pools_and_out;
2721
2722 pools->tio_pool = (type == DM_TYPE_BIO_BASED) ?
2723 mempool_create_slab_pool(MIN_IOS, _tio_cache) :
2724 mempool_create_slab_pool(MIN_IOS, _rq_tio_cache);
2725 if (!pools->tio_pool)
2726 goto free_io_pool_and_out;
2727
2728 pools->bs = (type == DM_TYPE_BIO_BASED) ?
2729 bioset_create(16, 0) : bioset_create(MIN_IOS, 0);
2730 if (!pools->bs)
2731 goto free_tio_pool_and_out;
2732
2733 return pools;
2734
2735free_tio_pool_and_out:
2736 mempool_destroy(pools->tio_pool);
2737
2738free_io_pool_and_out:
2739 mempool_destroy(pools->io_pool);
2740
2741free_pools_and_out:
2742 kfree(pools);
2743
2744 return NULL;
2745}
2746
2747void dm_free_md_mempools(struct dm_md_mempools *pools)
2748{
2749 if (!pools)
2750 return;
2751
2752 if (pools->io_pool)
2753 mempool_destroy(pools->io_pool);
2754
2755 if (pools->tio_pool)
2756 mempool_destroy(pools->tio_pool);
2757
2758 if (pools->bs)
2759 bioset_free(pools->bs);
2760
2761 kfree(pools);
2762}
2763
Alexey Dobriyan83d5cde2009-09-21 17:01:13 -07002764static const struct block_device_operations dm_blk_dops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002765 .open = dm_blk_open,
2766 .release = dm_blk_close,
Milan Brozaa129a22006-10-03 01:15:15 -07002767 .ioctl = dm_blk_ioctl,
Darrick J. Wong3ac51e72006-03-27 01:17:54 -08002768 .getgeo = dm_blk_getgeo,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002769 .owner = THIS_MODULE
2770};
2771
2772EXPORT_SYMBOL(dm_get_mapinfo);
2773
2774/*
2775 * module hooks
2776 */
2777module_init(dm_init);
2778module_exit(dm_exit);
2779
2780module_param(major, uint, 0);
2781MODULE_PARM_DESC(major, "The major number of the device mapper");
2782MODULE_DESCRIPTION(DM_NAME " driver");
2783MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2784MODULE_LICENSE("GPL");