blob: 5b48478c79f53037474579edf1930b4d103b160c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) 2003 Sistina Software
Heinz Mauelshagenb7fd54a2008-04-24 21:43:06 +01003 * 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 LGPL.
6 */
7
8#include <linux/init.h>
9#include <linux/slab.h>
10#include <linux/module.h>
11#include <linux/vmalloc.h>
Alasdair G Kergona765e202008-04-24 22:02:01 +010012#include <linux/dm-io.h>
13#include <linux/dm-dirty-log.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014
Heinz Mauelshagen416cd172008-04-24 21:43:35 +010015#include "dm.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
Heinz Mauelshagenb7fd54a2008-04-24 21:43:06 +010017#define DM_MSG_PREFIX "dirty region log"
Alasdair G Kergon72d94862006-06-26 00:27:35 -070018
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010019struct dm_dirty_log_internal {
20 struct dm_dirty_log_type *type;
21
22 struct list_head list;
23 long use;
24};
25
Linus Torvalds1da177e2005-04-16 15:20:36 -070026static LIST_HEAD(_log_types);
27static DEFINE_SPINLOCK(_lock);
28
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010029static struct dm_dirty_log_internal *__find_dirty_log_type(const char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030{
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010031 struct dm_dirty_log_internal *log_type;
32
33 list_for_each_entry(log_type, &_log_types, list)
34 if (!strcmp(name, log_type->type->name))
35 return log_type;
36
37 return NULL;
38}
39
40static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name)
41{
42 struct dm_dirty_log_internal *log_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
44 spin_lock(&_lock);
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010045
46 log_type = __find_dirty_log_type(name);
47 if (log_type) {
48 if (!log_type->use && !try_module_get(log_type->type->module))
49 log_type = NULL;
50 else
51 log_type->use++;
52 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54 spin_unlock(&_lock);
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010055
56 return log_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057}
58
Jonathan Brassowfb8b2842008-02-08 02:11:19 +000059/*
60 * get_type
61 * @type_name
62 *
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010063 * Attempt to retrieve the dm_dirty_log_type by name. If not already
Jonathan Brassowfb8b2842008-02-08 02:11:19 +000064 * available, attempt to load the appropriate module.
65 *
66 * Log modules are named "dm-log-" followed by the 'type_name'.
67 * Modules may contain multiple types.
68 * This function will first try the module "dm-log-<type_name>",
69 * then truncate 'type_name' on the last '-' and try again.
70 *
71 * For example, if type_name was "clustered-disk", it would search
72 * 'dm-log-clustered-disk' then 'dm-log-clustered'.
73 *
74 * Returns: dirty_log_type* on success, NULL on failure
75 */
Heinz Mauelshagen416cd172008-04-24 21:43:35 +010076static struct dm_dirty_log_type *get_type(const char *type_name)
Jonathan Brassowfb8b2842008-02-08 02:11:19 +000077{
78 char *p, *type_name_dup;
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010079 struct dm_dirty_log_internal *log_type;
Jonathan Brassowfb8b2842008-02-08 02:11:19 +000080
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010081 if (!type_name)
82 return NULL;
83
84 log_type = _get_dirty_log_type(type_name);
85 if (log_type)
86 return log_type->type;
Jonathan Brassowfb8b2842008-02-08 02:11:19 +000087
88 type_name_dup = kstrdup(type_name, GFP_KERNEL);
89 if (!type_name_dup) {
90 DMWARN("No memory left to attempt log module load for \"%s\"",
91 type_name);
92 return NULL;
93 }
94
95 while (request_module("dm-log-%s", type_name_dup) ||
Jonathan Brassow2a23aa12008-04-24 21:43:41 +010096 !(log_type = _get_dirty_log_type(type_name))) {
Jonathan Brassowfb8b2842008-02-08 02:11:19 +000097 p = strrchr(type_name_dup, '-');
98 if (!p)
99 break;
100 p[0] = '\0';
101 }
102
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100103 if (!log_type)
Jonathan Brassowfb8b2842008-02-08 02:11:19 +0000104 DMWARN("Module for logging type \"%s\" not found.", type_name);
105
106 kfree(type_name_dup);
107
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100108 return log_type ? log_type->type : NULL;
Jonathan Brassowfb8b2842008-02-08 02:11:19 +0000109}
110
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100111static void put_type(struct dm_dirty_log_type *type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112{
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100113 struct dm_dirty_log_internal *log_type;
114
115 if (!type)
116 return;
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 spin_lock(&_lock);
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100119 log_type = __find_dirty_log_type(type->name);
120 if (!log_type)
121 goto out;
122
123 if (!--log_type->use)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 module_put(type->module);
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100125
126 BUG_ON(log_type->use < 0);
127
128out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 spin_unlock(&_lock);
130}
131
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100132static struct dm_dirty_log_internal *_alloc_dirty_log_type(struct dm_dirty_log_type *type)
133{
134 struct dm_dirty_log_internal *log_type = kzalloc(sizeof(*log_type),
135 GFP_KERNEL);
136
137 if (log_type)
138 log_type->type = type;
139
140 return log_type;
141}
142
Alasdair G Kergonb8206bc2008-04-24 21:43:38 +0100143int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
144{
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100145 struct dm_dirty_log_internal *log_type = _alloc_dirty_log_type(type);
146 int r = 0;
147
148 if (!log_type)
149 return -ENOMEM;
150
Alasdair G Kergonb8206bc2008-04-24 21:43:38 +0100151 spin_lock(&_lock);
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100152 if (!__find_dirty_log_type(type->name))
153 list_add(&log_type->list, &_log_types);
154 else {
155 kfree(log_type);
156 r = -EEXIST;
157 }
Alasdair G Kergonb8206bc2008-04-24 21:43:38 +0100158 spin_unlock(&_lock);
159
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100160 return r;
Alasdair G Kergonb8206bc2008-04-24 21:43:38 +0100161}
162EXPORT_SYMBOL(dm_dirty_log_type_register);
163
164int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
165{
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100166 struct dm_dirty_log_internal *log_type;
167
Alasdair G Kergonb8206bc2008-04-24 21:43:38 +0100168 spin_lock(&_lock);
169
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100170 log_type = __find_dirty_log_type(type->name);
171 if (!log_type) {
172 spin_unlock(&_lock);
173 return -EINVAL;
174 }
175
176 if (log_type->use) {
177 spin_unlock(&_lock);
178 return -ETXTBSY;
179 }
180
181 list_del(&log_type->list);
Alasdair G Kergonb8206bc2008-04-24 21:43:38 +0100182
183 spin_unlock(&_lock);
Jonathan Brassow2a23aa12008-04-24 21:43:41 +0100184 kfree(log_type);
Alasdair G Kergonb8206bc2008-04-24 21:43:38 +0100185
186 return 0;
187}
188EXPORT_SYMBOL(dm_dirty_log_type_unregister);
189
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100190struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
191 struct dm_target *ti,
192 unsigned int argc, char **argv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193{
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100194 struct dm_dirty_log_type *type;
195 struct dm_dirty_log *log;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
197 log = kmalloc(sizeof(*log), GFP_KERNEL);
198 if (!log)
199 return NULL;
200
201 type = get_type(type_name);
202 if (!type) {
203 kfree(log);
204 return NULL;
205 }
206
207 log->type = type;
208 if (type->ctr(log, ti, argc, argv)) {
209 kfree(log);
210 put_type(type);
211 return NULL;
212 }
213
214 return log;
215}
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100216EXPORT_SYMBOL(dm_dirty_log_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100218void dm_dirty_log_destroy(struct dm_dirty_log *log)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219{
220 log->type->dtr(log);
221 put_type(log->type);
222 kfree(log);
223}
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100224EXPORT_SYMBOL(dm_dirty_log_destroy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
226/*-----------------------------------------------------------------
227 * Persistent and core logs share a lot of their implementation.
228 * FIXME: need a reload method to be called from a resume
229 *---------------------------------------------------------------*/
230/*
231 * Magic for persistent mirrors: "MiRr"
232 */
233#define MIRROR_MAGIC 0x4D695272
234
235/*
236 * The on-disk version of the metadata.
237 */
Patrick Caulfielda4fc4712006-02-01 03:04:51 -0800238#define MIRROR_DISK_VERSION 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239#define LOG_OFFSET 2
240
241struct log_header {
242 uint32_t magic;
243
244 /*
245 * Simple, incrementing version. no backward
246 * compatibility.
247 */
248 uint32_t version;
249 sector_t nr_regions;
250};
251
252struct log_c {
253 struct dm_target *ti;
254 int touched;
255 uint32_t region_size;
256 unsigned int region_count;
257 region_t sync_count;
258
259 unsigned bitset_uint32_count;
260 uint32_t *clean_bits;
261 uint32_t *sync_bits;
262 uint32_t *recovering_bits; /* FIXME: this seems excessive */
263
264 int sync_search;
265
266 /* Resync flag */
267 enum sync {
268 DEFAULTSYNC, /* Synchronize if necessary */
269 NOSYNC, /* Devices known to be already in sync */
270 FORCESYNC, /* Force a sync to happen */
271 } sync;
272
Heinz Mauelshagen5d234d12007-05-09 02:33:03 -0700273 struct dm_io_request io_req;
274
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 /*
276 * Disk log fields
277 */
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700278 int log_dev_failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 struct dm_dev *log_dev;
280 struct log_header header;
281
Heinz Mauelshagen22a1ceb2008-04-24 21:43:17 +0100282 struct dm_io_region header_location;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 struct log_header *disk_header;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284};
285
286/*
287 * The touched member needs to be updated every time we access
288 * one of the bitsets.
289 */
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100290static inline int log_test_bit(uint32_t *bs, unsigned bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291{
Patrick Caulfielda4fc4712006-02-01 03:04:51 -0800292 return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293}
294
295static inline void log_set_bit(struct log_c *l,
296 uint32_t *bs, unsigned bit)
297{
Patrick Caulfielda4fc4712006-02-01 03:04:51 -0800298 ext2_set_bit(bit, (unsigned long *) bs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 l->touched = 1;
300}
301
302static inline void log_clear_bit(struct log_c *l,
303 uint32_t *bs, unsigned bit)
304{
Patrick Caulfielda4fc4712006-02-01 03:04:51 -0800305 ext2_clear_bit(bit, (unsigned long *) bs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 l->touched = 1;
307}
308
309/*----------------------------------------------------------------
310 * Header IO
311 *--------------------------------------------------------------*/
312static void header_to_disk(struct log_header *core, struct log_header *disk)
313{
314 disk->magic = cpu_to_le32(core->magic);
315 disk->version = cpu_to_le32(core->version);
316 disk->nr_regions = cpu_to_le64(core->nr_regions);
317}
318
319static void header_from_disk(struct log_header *core, struct log_header *disk)
320{
321 core->magic = le32_to_cpu(disk->magic);
322 core->version = le32_to_cpu(disk->version);
323 core->nr_regions = le64_to_cpu(disk->nr_regions);
324}
325
Heinz Mauelshagen5d234d12007-05-09 02:33:03 -0700326static int rw_header(struct log_c *lc, int rw)
327{
328 lc->io_req.bi_rw = rw;
329 lc->io_req.mem.ptr.vma = lc->disk_header;
330 lc->io_req.notify.fn = NULL;
331
332 return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
333}
334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335static int read_header(struct log_c *log)
336{
337 int r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
Heinz Mauelshagen5d234d12007-05-09 02:33:03 -0700339 r = rw_header(log, READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 if (r)
341 return r;
342
343 header_from_disk(&log->header, log->disk_header);
344
345 /* New log required? */
346 if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
347 log->header.magic = MIRROR_MAGIC;
348 log->header.version = MIRROR_DISK_VERSION;
349 log->header.nr_regions = 0;
350 }
351
Patrick Caulfielda4fc4712006-02-01 03:04:51 -0800352#ifdef __LITTLE_ENDIAN
353 if (log->header.version == 1)
354 log->header.version = 2;
355#endif
356
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 if (log->header.version != MIRROR_DISK_VERSION) {
358 DMWARN("incompatible disk log version");
359 return -EINVAL;
360 }
361
362 return 0;
363}
364
365static inline int write_header(struct log_c *log)
366{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 header_to_disk(&log->header, log->disk_header);
Heinz Mauelshagen5d234d12007-05-09 02:33:03 -0700368 return rw_header(log, WRITE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369}
370
371/*----------------------------------------------------------------
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 * core log constructor/destructor
373 *
374 * argv contains region_size followed optionally by [no]sync
375 *--------------------------------------------------------------*/
376#define BYTE_SHIFT 3
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100377static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700378 unsigned int argc, char **argv,
379 struct dm_dev *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380{
381 enum sync sync = DEFAULTSYNC;
382
383 struct log_c *lc;
384 uint32_t region_size;
385 unsigned int region_count;
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700386 size_t bitset_size, buf_size;
Heinz Mauelshagen5d234d12007-05-09 02:33:03 -0700387 int r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
389 if (argc < 1 || argc > 2) {
Heinz Mauelshagenb7fd54a2008-04-24 21:43:06 +0100390 DMWARN("wrong number of arguments to dirty region log");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 return -EINVAL;
392 }
393
394 if (argc > 1) {
395 if (!strcmp(argv[1], "sync"))
396 sync = FORCESYNC;
397 else if (!strcmp(argv[1], "nosync"))
398 sync = NOSYNC;
399 else {
Heinz Mauelshagenb7fd54a2008-04-24 21:43:06 +0100400 DMWARN("unrecognised sync argument to "
401 "dirty region log: %s", argv[1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 return -EINVAL;
403 }
404 }
405
406 if (sscanf(argv[0], "%u", &region_size) != 1) {
407 DMWARN("invalid region size string");
408 return -EINVAL;
409 }
410
411 region_count = dm_sector_div_up(ti->len, region_size);
412
413 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
414 if (!lc) {
415 DMWARN("couldn't allocate core log");
416 return -ENOMEM;
417 }
418
419 lc->ti = ti;
420 lc->touched = 0;
421 lc->region_size = region_size;
422 lc->region_count = region_count;
423 lc->sync = sync;
424
425 /*
Alasdair G Kergon0e568222005-11-21 21:32:34 -0800426 * Work out how many "unsigned long"s we need to hold the bitset.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 */
428 bitset_size = dm_round_up(region_count,
Alasdair G Kergon29121bd2006-06-26 00:27:29 -0700429 sizeof(*lc->clean_bits) << BYTE_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 bitset_size >>= BYTE_SHIFT;
431
Alasdair G Kergon29121bd2006-06-26 00:27:29 -0700432 lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700433
434 /*
435 * Disk log?
436 */
437 if (!dev) {
438 lc->clean_bits = vmalloc(bitset_size);
439 if (!lc->clean_bits) {
440 DMWARN("couldn't allocate clean bitset");
441 kfree(lc);
442 return -ENOMEM;
443 }
444 lc->disk_header = NULL;
445 } else {
446 lc->log_dev = dev;
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700447 lc->log_dev_failed = 0;
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700448 lc->header_location.bdev = lc->log_dev->bdev;
449 lc->header_location.sector = 0;
450
451 /*
452 * Buffer holds both header and bitset.
453 */
454 buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
455 bitset_size, ti->limits.hardsect_size);
456 lc->header_location.count = buf_size >> SECTOR_SHIFT;
Heinz Mauelshagen5d234d12007-05-09 02:33:03 -0700457 lc->io_req.mem.type = DM_IO_VMA;
458 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
459 PAGE_SIZE));
460 if (IS_ERR(lc->io_req.client)) {
461 r = PTR_ERR(lc->io_req.client);
462 DMWARN("couldn't allocate disk io client");
463 kfree(lc);
464 return -ENOMEM;
465 }
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700466
467 lc->disk_header = vmalloc(buf_size);
468 if (!lc->disk_header) {
469 DMWARN("couldn't allocate disk log buffer");
470 kfree(lc);
471 return -ENOMEM;
472 }
473
474 lc->clean_bits = (void *)lc->disk_header +
475 (LOG_OFFSET << SECTOR_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 }
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 memset(lc->clean_bits, -1, bitset_size);
479
480 lc->sync_bits = vmalloc(bitset_size);
481 if (!lc->sync_bits) {
482 DMWARN("couldn't allocate sync bitset");
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700483 if (!dev)
484 vfree(lc->clean_bits);
485 vfree(lc->disk_header);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 kfree(lc);
487 return -ENOMEM;
488 }
489 memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
490 lc->sync_count = (sync == NOSYNC) ? region_count : 0;
491
492 lc->recovering_bits = vmalloc(bitset_size);
493 if (!lc->recovering_bits) {
494 DMWARN("couldn't allocate sync bitset");
495 vfree(lc->sync_bits);
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700496 if (!dev)
497 vfree(lc->clean_bits);
498 vfree(lc->disk_header);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 kfree(lc);
500 return -ENOMEM;
501 }
502 memset(lc->recovering_bits, 0, bitset_size);
503 lc->sync_search = 0;
504 log->context = lc;
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700505
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 return 0;
507}
508
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100509static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700510 unsigned int argc, char **argv)
511{
512 return create_log_context(log, ti, argc, argv, NULL);
513}
514
515static void destroy_log_context(struct log_c *lc)
516{
517 vfree(lc->sync_bits);
518 vfree(lc->recovering_bits);
519 kfree(lc);
520}
521
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100522static void core_dtr(struct dm_dirty_log *log)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523{
524 struct log_c *lc = (struct log_c *) log->context;
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700525
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 vfree(lc->clean_bits);
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700527 destroy_log_context(lc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528}
529
530/*----------------------------------------------------------------
531 * disk log constructor/destructor
532 *
533 * argv contains log_device region_size followed optionally by [no]sync
534 *--------------------------------------------------------------*/
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100535static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 unsigned int argc, char **argv)
537{
538 int r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 struct dm_dev *dev;
540
541 if (argc < 2 || argc > 3) {
Heinz Mauelshagenb7fd54a2008-04-24 21:43:06 +0100542 DMWARN("wrong number of arguments to disk dirty region log");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 return -EINVAL;
544 }
545
546 r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
547 FMODE_READ | FMODE_WRITE, &dev);
548 if (r)
549 return r;
550
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700551 r = create_log_context(log, ti, argc - 1, argv + 1, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 if (r) {
553 dm_put_device(ti, dev);
554 return r;
555 }
556
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558}
559
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100560static void disk_dtr(struct dm_dirty_log *log)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561{
562 struct log_c *lc = (struct log_c *) log->context;
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700563
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 dm_put_device(lc->ti, lc->log_dev);
565 vfree(lc->disk_header);
Heinz Mauelshagen5d234d12007-05-09 02:33:03 -0700566 dm_io_client_destroy(lc->io_req.client);
Alasdair G Kergonb7cca192006-06-26 00:27:29 -0700567 destroy_log_context(lc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568}
569
570static int count_bits32(uint32_t *addr, unsigned size)
571{
572 int count = 0, i;
573
574 for (i = 0; i < size; i++) {
575 count += hweight32(*(addr+i));
576 }
577 return count;
578}
579
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700580static void fail_log_device(struct log_c *lc)
581{
582 if (lc->log_dev_failed)
583 return;
584
585 lc->log_dev_failed = 1;
586 dm_table_event(lc->ti->table);
587}
588
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100589static int disk_resume(struct dm_dirty_log *log)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590{
591 int r;
592 unsigned i;
593 struct log_c *lc = (struct log_c *) log->context;
594 size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
595
596 /* read the disk header */
597 r = read_header(lc);
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700598 if (r) {
Heinz Mauelshagenb7fd54a2008-04-24 21:43:06 +0100599 DMWARN("%s: Failed to read header on dirty region log device",
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700600 lc->log_dev->name);
601 fail_log_device(lc);
Jonathan Brassowba8b45c2007-05-09 02:33:08 -0700602 /*
603 * If the log device cannot be read, we must assume
604 * all regions are out-of-sync. If we simply return
605 * here, the state will be uninitialized and could
606 * lead us to return 'in-sync' status for regions
607 * that are actually 'out-of-sync'.
608 */
609 lc->header.nr_regions = 0;
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700610 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
Alasdair G Kergon8a835f12006-06-26 00:27:30 -0700612 /* set or clear any new bits -- device has grown */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 if (lc->sync == NOSYNC)
614 for (i = lc->header.nr_regions; i < lc->region_count; i++)
615 /* FIXME: amazingly inefficient */
616 log_set_bit(lc, lc->clean_bits, i);
617 else
618 for (i = lc->header.nr_regions; i < lc->region_count; i++)
619 /* FIXME: amazingly inefficient */
620 log_clear_bit(lc, lc->clean_bits, i);
621
Alasdair G Kergon8a835f12006-06-26 00:27:30 -0700622 /* clear any old bits -- device has shrunk */
623 for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
624 log_clear_bit(lc, lc->clean_bits, i);
625
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 /* copy clean across to sync */
627 memcpy(lc->sync_bits, lc->clean_bits, size);
628 lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
Jonathan E Brassow88b20a12006-12-08 02:41:12 -0800629 lc->sync_search = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 /* set the correct number of regions in the header */
632 lc->header.nr_regions = lc->region_count;
633
634 /* write the new header */
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700635 r = write_header(lc);
636 if (r) {
Heinz Mauelshagenb7fd54a2008-04-24 21:43:06 +0100637 DMWARN("%s: Failed to write header on dirty region log device",
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700638 lc->log_dev->name);
639 fail_log_device(lc);
640 }
641
642 return r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643}
644
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100645static uint32_t core_get_region_size(struct dm_dirty_log *log)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646{
647 struct log_c *lc = (struct log_c *) log->context;
648 return lc->region_size;
649}
650
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100651static int core_resume(struct dm_dirty_log *log)
Jonathan E Brassow88b20a12006-12-08 02:41:12 -0800652{
653 struct log_c *lc = (struct log_c *) log->context;
654 lc->sync_search = 0;
655 return 0;
656}
657
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100658static int core_is_clean(struct dm_dirty_log *log, region_t region)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659{
660 struct log_c *lc = (struct log_c *) log->context;
661 return log_test_bit(lc->clean_bits, region);
662}
663
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100664static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665{
666 struct log_c *lc = (struct log_c *) log->context;
667 return log_test_bit(lc->sync_bits, region);
668}
669
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100670static int core_flush(struct dm_dirty_log *log)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671{
672 /* no op */
673 return 0;
674}
675
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100676static int disk_flush(struct dm_dirty_log *log)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677{
678 int r;
679 struct log_c *lc = (struct log_c *) log->context;
680
681 /* only write if the log has changed */
682 if (!lc->touched)
683 return 0;
684
Kevin Corry702ca6f2006-06-26 00:27:28 -0700685 r = write_header(lc);
Jonathan E Brassow01d03a62007-05-09 02:32:57 -0700686 if (r)
687 fail_log_device(lc);
688 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 lc->touched = 0;
690
691 return r;
692}
693
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100694static void core_mark_region(struct dm_dirty_log *log, region_t region)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695{
696 struct log_c *lc = (struct log_c *) log->context;
697 log_clear_bit(lc, lc->clean_bits, region);
698}
699
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100700static void core_clear_region(struct dm_dirty_log *log, region_t region)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701{
702 struct log_c *lc = (struct log_c *) log->context;
703 log_set_bit(lc, lc->clean_bits, region);
704}
705
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100706static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707{
708 struct log_c *lc = (struct log_c *) log->context;
709
710 if (lc->sync_search >= lc->region_count)
711 return 0;
712
713 do {
Stefan Bader1113a7e2006-02-02 14:28:07 -0800714 *region = ext2_find_next_zero_bit(
715 (unsigned long *) lc->sync_bits,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 lc->region_count,
717 lc->sync_search);
718 lc->sync_search = *region + 1;
719
Darrick J. Wongac81b2e2006-01-06 00:20:11 -0800720 if (*region >= lc->region_count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 return 0;
722
723 } while (log_test_bit(lc->recovering_bits, *region));
724
725 log_set_bit(lc, lc->recovering_bits, *region);
726 return 1;
727}
728
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100729static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
Jonathan E Brassowf3ee6b22006-12-08 02:41:11 -0800730 int in_sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731{
732 struct log_c *lc = (struct log_c *) log->context;
733
734 log_clear_bit(lc, lc->recovering_bits, region);
Jonathan E Brassowf3ee6b22006-12-08 02:41:11 -0800735 if (in_sync) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 log_set_bit(lc, lc->sync_bits, region);
737 lc->sync_count++;
Jonathan E Brassowf3ee6b22006-12-08 02:41:11 -0800738 } else if (log_test_bit(lc->sync_bits, region)) {
739 lc->sync_count--;
740 log_clear_bit(lc, lc->sync_bits, region);
741 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742}
743
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100744static region_t core_get_sync_count(struct dm_dirty_log *log)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745{
746 struct log_c *lc = (struct log_c *) log->context;
747
748 return lc->sync_count;
749}
750
751#define DMEMIT_SYNC \
752 if (lc->sync != DEFAULTSYNC) \
753 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
754
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100755static int core_status(struct dm_dirty_log *log, status_type_t status,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 char *result, unsigned int maxlen)
757{
758 int sz = 0;
759 struct log_c *lc = log->context;
760
761 switch(status) {
762 case STATUSTYPE_INFO:
Jonathan E Brassow315dcc22007-05-09 02:32:58 -0700763 DMEMIT("1 %s", log->type->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 break;
765
766 case STATUSTYPE_TABLE:
767 DMEMIT("%s %u %u ", log->type->name,
768 lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
769 DMEMIT_SYNC;
770 }
771
772 return sz;
773}
774
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100775static int disk_status(struct dm_dirty_log *log, status_type_t status,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 char *result, unsigned int maxlen)
777{
778 int sz = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 struct log_c *lc = log->context;
780
781 switch(status) {
782 case STATUSTYPE_INFO:
Jonathan E Brassow315dcc22007-05-09 02:32:58 -0700783 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
784 lc->log_dev_failed ? 'D' : 'A');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 break;
786
787 case STATUSTYPE_TABLE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 DMEMIT("%s %u %s %u ", log->type->name,
Jonathan E Brassow315dcc22007-05-09 02:32:58 -0700789 lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 lc->region_size);
791 DMEMIT_SYNC;
792 }
793
794 return sz;
795}
796
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100797static struct dm_dirty_log_type _core_type = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 .name = "core",
799 .module = THIS_MODULE,
800 .ctr = core_ctr,
801 .dtr = core_dtr,
Jonathan E Brassow88b20a12006-12-08 02:41:12 -0800802 .resume = core_resume,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 .get_region_size = core_get_region_size,
804 .is_clean = core_is_clean,
805 .in_sync = core_in_sync,
806 .flush = core_flush,
807 .mark_region = core_mark_region,
808 .clear_region = core_clear_region,
809 .get_resync_work = core_get_resync_work,
Jonathan E Brassowf3ee6b22006-12-08 02:41:11 -0800810 .set_region_sync = core_set_region_sync,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 .get_sync_count = core_get_sync_count,
812 .status = core_status,
813};
814
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100815static struct dm_dirty_log_type _disk_type = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 .name = "disk",
817 .module = THIS_MODULE,
818 .ctr = disk_ctr,
819 .dtr = disk_dtr,
Jonathan Brassow6b3df0d2007-10-19 22:47:57 +0100820 .postsuspend = disk_flush,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821 .resume = disk_resume,
822 .get_region_size = core_get_region_size,
823 .is_clean = core_is_clean,
824 .in_sync = core_in_sync,
825 .flush = disk_flush,
826 .mark_region = core_mark_region,
827 .clear_region = core_clear_region,
828 .get_resync_work = core_get_resync_work,
Jonathan E Brassowf3ee6b22006-12-08 02:41:11 -0800829 .set_region_sync = core_set_region_sync,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 .get_sync_count = core_get_sync_count,
831 .status = disk_status,
832};
833
Adrian Bunkc8da2f82008-07-21 12:00:27 +0100834static int __init dm_dirty_log_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835{
836 int r;
837
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100838 r = dm_dirty_log_type_register(&_core_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 if (r)
840 DMWARN("couldn't register core log");
841
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100842 r = dm_dirty_log_type_register(&_disk_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843 if (r) {
844 DMWARN("couldn't register disk type");
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100845 dm_dirty_log_type_unregister(&_core_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 }
847
848 return r;
849}
850
Adrian Bunkc8da2f82008-07-21 12:00:27 +0100851static void __exit dm_dirty_log_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852{
Heinz Mauelshagen416cd172008-04-24 21:43:35 +0100853 dm_dirty_log_type_unregister(&_disk_type);
854 dm_dirty_log_type_unregister(&_core_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855}
856
Heinz Mauelshagen769aef32008-04-24 21:43:09 +0100857module_init(dm_dirty_log_init);
858module_exit(dm_dirty_log_exit);
859
860MODULE_DESCRIPTION(DM_NAME " dirty region log");
861MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
862MODULE_LICENSE("GPL");