blob: aa2e0c374ab3e0c985e6bdc6536807bc07bcf3ce [file] [log] [blame]
Jonthan Brassowf5db4af2009-06-22 10:12:35 +01001/*
2 * Copyright (C) 2006-2009 Red Hat, Inc.
3 *
4 * This file is released under the LGPL.
5 */
6
7#include <linux/bio.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09008#include <linux/slab.h>
Jonthan Brassowf5db4af2009-06-22 10:12:35 +01009#include <linux/dm-dirty-log.h>
10#include <linux/device-mapper.h>
11#include <linux/dm-log-userspace.h>
12
13#include "dm-log-userspace-transfer.h"
14
Jonathan Brassow86a54a482011-01-13 19:59:52 +000015#define DM_LOG_USERSPACE_VSN "1.1.0"
16
Jonthan Brassowf5db4af2009-06-22 10:12:35 +010017struct flush_entry {
18 int type;
19 region_t region;
20 struct list_head list;
21};
22
Jonathan Brassow085ae062011-01-13 19:59:51 +000023/*
24 * This limit on the number of mark and clear request is, to a degree,
25 * arbitrary. However, there is some basis for the choice in the limits
26 * imposed on the size of data payload by dm-log-userspace-transfer.c:
27 * dm_consult_userspace().
28 */
29#define MAX_FLUSH_GROUP_COUNT 32
30
Jonthan Brassowf5db4af2009-06-22 10:12:35 +010031struct log_c {
32 struct dm_target *ti;
33 uint32_t region_size;
34 region_t region_count;
Jonathan Brassow7ec23d52009-09-04 20:40:34 +010035 uint64_t luid;
Jonthan Brassowf5db4af2009-06-22 10:12:35 +010036 char uuid[DM_UUID_LEN];
37
38 char *usr_argv_str;
39 uint32_t usr_argc;
40
41 /*
42 * in_sync_hint gets set when doing is_remote_recovering. It
43 * represents the first region that needs recovery. IOW, the
44 * first zero bit of sync_bits. This can be useful for to limit
45 * traffic for calls like is_remote_recovering and get_resync_work,
46 * but be take care in its use for anything else.
47 */
48 uint64_t in_sync_hint;
49
Jonathan Brassow909cc4f2011-01-13 19:59:50 +000050 /*
51 * Mark and clear requests are held until a flush is issued
52 * so that we can group, and thereby limit, the amount of
53 * network traffic between kernel and userspace. The 'flush_lock'
54 * is used to protect these lists.
55 */
Jonthan Brassowf5db4af2009-06-22 10:12:35 +010056 spinlock_t flush_lock;
Jonathan Brassow909cc4f2011-01-13 19:59:50 +000057 struct list_head mark_list;
58 struct list_head clear_list;
Jonthan Brassowf5db4af2009-06-22 10:12:35 +010059};
60
61static mempool_t *flush_entry_pool;
62
63static void *flush_entry_alloc(gfp_t gfp_mask, void *pool_data)
64{
65 return kmalloc(sizeof(struct flush_entry), gfp_mask);
66}
67
68static void flush_entry_free(void *element, void *pool_data)
69{
70 kfree(element);
71}
72
73static int userspace_do_request(struct log_c *lc, const char *uuid,
74 int request_type, char *data, size_t data_size,
75 char *rdata, size_t *rdata_size)
76{
77 int r;
78
79 /*
80 * If the server isn't there, -ESRCH is returned,
81 * and we must keep trying until the server is
82 * restored.
83 */
84retry:
Jonathan Brassow7ec23d52009-09-04 20:40:34 +010085 r = dm_consult_userspace(uuid, lc->luid, request_type, data,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +010086 data_size, rdata, rdata_size);
87
88 if (r != -ESRCH)
89 return r;
90
91 DMERR(" Userspace log server not found.");
92 while (1) {
93 set_current_state(TASK_INTERRUPTIBLE);
94 schedule_timeout(2*HZ);
95 DMWARN("Attempting to contact userspace log server...");
Jonathan Brassow7ec23d52009-09-04 20:40:34 +010096 r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_CTR,
97 lc->usr_argv_str,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +010098 strlen(lc->usr_argv_str) + 1,
99 NULL, NULL);
100 if (!r)
101 break;
102 }
103 DMINFO("Reconnected to userspace log server... DM_ULOG_CTR complete");
Jonathan Brassow7ec23d52009-09-04 20:40:34 +0100104 r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_RESUME, NULL,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100105 0, NULL, NULL);
106 if (!r)
107 goto retry;
108
109 DMERR("Error trying to resume userspace log: %d", r);
110
111 return -ESRCH;
112}
113
114static int build_constructor_string(struct dm_target *ti,
115 unsigned argc, char **argv,
116 char **ctr_str)
117{
118 int i, str_size;
119 char *str = NULL;
120
121 *ctr_str = NULL;
122
123 for (i = 0, str_size = 0; i < argc; i++)
124 str_size += strlen(argv[i]) + 1; /* +1 for space between args */
125
126 str_size += 20; /* Max number of chars in a printed u64 number */
127
128 str = kzalloc(str_size, GFP_KERNEL);
129 if (!str) {
130 DMWARN("Unable to allocate memory for constructor string");
131 return -ENOMEM;
132 }
133
Jonathan Brassowb8313b62009-09-04 20:40:30 +0100134 str_size = sprintf(str, "%llu", (unsigned long long)ti->len);
135 for (i = 0; i < argc; i++)
136 str_size += sprintf(str + str_size, " %s", argv[i]);
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100137
138 *ctr_str = str;
139 return str_size;
140}
141
142/*
143 * userspace_ctr
144 *
145 * argv contains:
146 * <UUID> <other args>
147 * Where 'other args' is the userspace implementation specific log
148 * arguments. An example might be:
149 * <UUID> clustered_disk <arg count> <log dev> <region_size> [[no]sync]
150 *
151 * So, this module will strip off the <UUID> for identification purposes
152 * when communicating with userspace about a log; but will pass on everything
153 * else.
154 */
155static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
156 unsigned argc, char **argv)
157{
158 int r = 0;
159 int str_size;
160 char *ctr_str = NULL;
161 struct log_c *lc = NULL;
162 uint64_t rdata;
163 size_t rdata_size = sizeof(rdata);
164
165 if (argc < 3) {
166 DMWARN("Too few arguments to userspace dirty log");
167 return -EINVAL;
168 }
169
170 lc = kmalloc(sizeof(*lc), GFP_KERNEL);
171 if (!lc) {
172 DMWARN("Unable to allocate userspace log context.");
173 return -ENOMEM;
174 }
175
Jonathan Brassow7ec23d52009-09-04 20:40:34 +0100176 /* The ptr value is sufficient for local unique id */
Andrew Mortonbca915a2009-10-16 23:18:15 +0100177 lc->luid = (unsigned long)lc;
Jonathan Brassow7ec23d52009-09-04 20:40:34 +0100178
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100179 lc->ti = ti;
180
181 if (strlen(argv[0]) > (DM_UUID_LEN - 1)) {
182 DMWARN("UUID argument too long.");
183 kfree(lc);
184 return -EINVAL;
185 }
186
187 strncpy(lc->uuid, argv[0], DM_UUID_LEN);
188 spin_lock_init(&lc->flush_lock);
Jonathan Brassow909cc4f2011-01-13 19:59:50 +0000189 INIT_LIST_HEAD(&lc->mark_list);
190 INIT_LIST_HEAD(&lc->clear_list);
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100191
192 str_size = build_constructor_string(ti, argc - 1, argv + 1, &ctr_str);
193 if (str_size < 0) {
194 kfree(lc);
195 return str_size;
196 }
197
198 /* Send table string */
Jonathan Brassow7ec23d52009-09-04 20:40:34 +0100199 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100200 ctr_str, str_size, NULL, NULL);
201
Jonathan Brassow4a038672011-01-13 19:59:49 +0000202 if (r < 0) {
203 if (r == -ESRCH)
204 DMERR("Userspace log server not found");
205 else
206 DMERR("Userspace log server failed to create log");
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100207 goto out;
208 }
209
210 /* Since the region size does not change, get it now */
211 rdata_size = sizeof(rdata);
Jonathan Brassow7ec23d52009-09-04 20:40:34 +0100212 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_GET_REGION_SIZE,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100213 NULL, 0, (char *)&rdata, &rdata_size);
214
215 if (r) {
216 DMERR("Failed to get region size of dirty log");
217 goto out;
218 }
219
220 lc->region_size = (uint32_t)rdata;
221 lc->region_count = dm_sector_div_up(ti->len, lc->region_size);
222
223out:
224 if (r) {
225 kfree(lc);
226 kfree(ctr_str);
227 } else {
228 lc->usr_argv_str = ctr_str;
229 lc->usr_argc = argc;
230 log->context = lc;
231 }
232
233 return r;
234}
235
236static void userspace_dtr(struct dm_dirty_log *log)
237{
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100238 struct log_c *lc = log->context;
239
Jonathan Brassow4a038672011-01-13 19:59:49 +0000240 (void) dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100241 NULL, 0,
242 NULL, NULL);
243
244 kfree(lc->usr_argv_str);
245 kfree(lc);
246
247 return;
248}
249
250static int userspace_presuspend(struct dm_dirty_log *log)
251{
252 int r;
253 struct log_c *lc = log->context;
254
Jonathan Brassow7ec23d52009-09-04 20:40:34 +0100255 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_PRESUSPEND,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100256 NULL, 0,
257 NULL, NULL);
258
259 return r;
260}
261
262static int userspace_postsuspend(struct dm_dirty_log *log)
263{
264 int r;
265 struct log_c *lc = log->context;
266
Jonathan Brassow7ec23d52009-09-04 20:40:34 +0100267 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_POSTSUSPEND,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100268 NULL, 0,
269 NULL, NULL);
270
271 return r;
272}
273
274static int userspace_resume(struct dm_dirty_log *log)
275{
276 int r;
277 struct log_c *lc = log->context;
278
279 lc->in_sync_hint = 0;
Jonathan Brassow7ec23d52009-09-04 20:40:34 +0100280 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_RESUME,
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100281 NULL, 0,
282 NULL, NULL);
283
284 return r;
285}
286
287static uint32_t userspace_get_region_size(struct dm_dirty_log *log)
288{
289 struct log_c *lc = log->context;
290
291 return lc->region_size;
292}
293
294/*
295 * userspace_is_clean
296 *
297 * Check whether a region is clean. If there is any sort of
298 * failure when consulting the server, we return not clean.
299 *
300 * Returns: 1 if clean, 0 otherwise
301 */
302static int userspace_is_clean(struct dm_dirty_log *log, region_t region)
303{
304 int r;
305 uint64_t region64 = (uint64_t)region;
306 int64_t is_clean;
307 size_t rdata_size;
308 struct log_c *lc = log->context;
309
310 rdata_size = sizeof(is_clean);
311 r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_CLEAN,
312 (char *)&region64, sizeof(region64),
313 (char *)&is_clean, &rdata_size);
314
315 return (r) ? 0 : (int)is_clean;
316}
317
318/*
319 * userspace_in_sync
320 *
321 * Check if the region is in-sync. If there is any sort
322 * of failure when consulting the server, we assume that
323 * the region is not in sync.
324 *
325 * If 'can_block' is set, return immediately
326 *
327 * Returns: 1 if in-sync, 0 if not-in-sync, -EWOULDBLOCK
328 */
329static int userspace_in_sync(struct dm_dirty_log *log, region_t region,
330 int can_block)
331{
332 int r;
333 uint64_t region64 = region;
334 int64_t in_sync;
335 size_t rdata_size;
336 struct log_c *lc = log->context;
337
338 /*
339 * We can never respond directly - even if in_sync_hint is
340 * set. This is because another machine could see a device
341 * failure and mark the region out-of-sync. If we don't go
342 * to userspace to ask, we might think the region is in-sync
343 * and allow a read to pick up data that is stale. (This is
344 * very unlikely if a device actually fails; but it is very
345 * likely if a connection to one device from one machine fails.)
346 *
347 * There still might be a problem if the mirror caches the region
348 * state as in-sync... but then this call would not be made. So,
349 * that is a mirror problem.
350 */
351 if (!can_block)
352 return -EWOULDBLOCK;
353
354 rdata_size = sizeof(in_sync);
355 r = userspace_do_request(lc, lc->uuid, DM_ULOG_IN_SYNC,
356 (char *)&region64, sizeof(region64),
357 (char *)&in_sync, &rdata_size);
358 return (r) ? 0 : (int)in_sync;
359}
360
Jonathan Brassow085ae062011-01-13 19:59:51 +0000361static int flush_one_by_one(struct log_c *lc, struct list_head *flush_list)
362{
363 int r = 0;
364 struct flush_entry *fe;
365
366 list_for_each_entry(fe, flush_list, list) {
367 r = userspace_do_request(lc, lc->uuid, fe->type,
368 (char *)&fe->region,
369 sizeof(fe->region),
370 NULL, NULL);
371 if (r)
372 break;
373 }
374
375 return r;
376}
377
378static int flush_by_group(struct log_c *lc, struct list_head *flush_list)
379{
380 int r = 0;
381 int count;
382 uint32_t type = 0;
383 struct flush_entry *fe, *tmp_fe;
384 LIST_HEAD(tmp_list);
385 uint64_t group[MAX_FLUSH_GROUP_COUNT];
386
387 /*
388 * Group process the requests
389 */
390 while (!list_empty(flush_list)) {
391 count = 0;
392
393 list_for_each_entry_safe(fe, tmp_fe, flush_list, list) {
394 group[count] = fe->region;
395 count++;
396
397 list_del(&fe->list);
398 list_add(&fe->list, &tmp_list);
399
400 type = fe->type;
401 if (count >= MAX_FLUSH_GROUP_COUNT)
402 break;
403 }
404
405 r = userspace_do_request(lc, lc->uuid, type,
406 (char *)(group),
407 count * sizeof(uint64_t),
408 NULL, NULL);
409 if (r) {
410 /* Group send failed. Attempt one-by-one. */
411 list_splice_init(&tmp_list, flush_list);
412 r = flush_one_by_one(lc, flush_list);
413 break;
414 }
415 }
416
417 /*
418 * Must collect flush_entrys that were successfully processed
419 * as a group so that they will be free'd by the caller.
420 */
421 list_splice_init(&tmp_list, flush_list);
422
423 return r;
424}
425
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100426/*
427 * userspace_flush
428 *
429 * This function is ok to block.
430 * The flush happens in two stages. First, it sends all
431 * clear/mark requests that are on the list. Then it
432 * tells the server to commit them. This gives the
433 * server a chance to optimise the commit, instead of
434 * doing it for every request.
435 *
436 * Additionally, we could implement another thread that
437 * sends the requests up to the server - reducing the
438 * load on flush. Then the flush would have less in
439 * the list and be responsible for the finishing commit.
440 *
441 * Returns: 0 on success, < 0 on failure
442 */
443static int userspace_flush(struct dm_dirty_log *log)
444{
445 int r = 0;
446 unsigned long flags;
447 struct log_c *lc = log->context;
Jonathan Brassow909cc4f2011-01-13 19:59:50 +0000448 LIST_HEAD(mark_list);
449 LIST_HEAD(clear_list);
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100450 struct flush_entry *fe, *tmp_fe;
451
452 spin_lock_irqsave(&lc->flush_lock, flags);
Jonathan Brassow909cc4f2011-01-13 19:59:50 +0000453 list_splice_init(&lc->mark_list, &mark_list);
454 list_splice_init(&lc->clear_list, &clear_list);
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100455 spin_unlock_irqrestore(&lc->flush_lock, flags);
456
Jonathan Brassow909cc4f2011-01-13 19:59:50 +0000457 if (list_empty(&mark_list) && list_empty(&clear_list))
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100458 return 0;
459
Jonathan Brassow085ae062011-01-13 19:59:51 +0000460 r = flush_by_group(lc, &mark_list);
461 if (r)
462 goto fail;
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100463
Jonathan Brassow085ae062011-01-13 19:59:51 +0000464 r = flush_by_group(lc, &clear_list);
465 if (r)
466 goto fail;
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100467
468 r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH,
469 NULL, 0, NULL, NULL);
470
471fail:
472 /*
473 * We can safely remove these entries, even if failure.
474 * Calling code will receive an error and will know that
475 * the log facility has failed.
476 */
Jonathan Brassow909cc4f2011-01-13 19:59:50 +0000477 list_for_each_entry_safe(fe, tmp_fe, &mark_list, list) {
478 list_del(&fe->list);
479 mempool_free(fe, flush_entry_pool);
480 }
481 list_for_each_entry_safe(fe, tmp_fe, &clear_list, list) {
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100482 list_del(&fe->list);
483 mempool_free(fe, flush_entry_pool);
484 }
485
486 if (r)
487 dm_table_event(lc->ti->table);
488
489 return r;
490}
491
492/*
493 * userspace_mark_region
494 *
495 * This function should avoid blocking unless absolutely required.
496 * (Memory allocation is valid for blocking.)
497 */
498static void userspace_mark_region(struct dm_dirty_log *log, region_t region)
499{
500 unsigned long flags;
501 struct log_c *lc = log->context;
502 struct flush_entry *fe;
503
504 /* Wait for an allocation, but _never_ fail */
505 fe = mempool_alloc(flush_entry_pool, GFP_NOIO);
506 BUG_ON(!fe);
507
508 spin_lock_irqsave(&lc->flush_lock, flags);
509 fe->type = DM_ULOG_MARK_REGION;
510 fe->region = region;
Jonathan Brassow909cc4f2011-01-13 19:59:50 +0000511 list_add(&fe->list, &lc->mark_list);
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100512 spin_unlock_irqrestore(&lc->flush_lock, flags);
513
514 return;
515}
516
517/*
518 * userspace_clear_region
519 *
520 * This function must not block.
521 * So, the alloc can't block. In the worst case, it is ok to
522 * fail. It would simply mean we can't clear the region.
523 * Does nothing to current sync context, but does mean
524 * the region will be re-sync'ed on a reload of the mirror
525 * even though it is in-sync.
526 */
527static void userspace_clear_region(struct dm_dirty_log *log, region_t region)
528{
529 unsigned long flags;
530 struct log_c *lc = log->context;
531 struct flush_entry *fe;
532
533 /*
534 * If we fail to allocate, we skip the clearing of
535 * the region. This doesn't hurt us in any way, except
536 * to cause the region to be resync'ed when the
537 * device is activated next time.
538 */
539 fe = mempool_alloc(flush_entry_pool, GFP_ATOMIC);
540 if (!fe) {
541 DMERR("Failed to allocate memory to clear region.");
542 return;
543 }
544
545 spin_lock_irqsave(&lc->flush_lock, flags);
546 fe->type = DM_ULOG_CLEAR_REGION;
547 fe->region = region;
Jonathan Brassow909cc4f2011-01-13 19:59:50 +0000548 list_add(&fe->list, &lc->clear_list);
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100549 spin_unlock_irqrestore(&lc->flush_lock, flags);
550
551 return;
552}
553
554/*
555 * userspace_get_resync_work
556 *
557 * Get a region that needs recovery. It is valid to return
558 * an error for this function.
559 *
560 * Returns: 1 if region filled, 0 if no work, <0 on error
561 */
562static int userspace_get_resync_work(struct dm_dirty_log *log, region_t *region)
563{
564 int r;
565 size_t rdata_size;
566 struct log_c *lc = log->context;
567 struct {
568 int64_t i; /* 64-bit for mix arch compatibility */
569 region_t r;
570 } pkg;
571
572 if (lc->in_sync_hint >= lc->region_count)
573 return 0;
574
575 rdata_size = sizeof(pkg);
576 r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_RESYNC_WORK,
577 NULL, 0,
578 (char *)&pkg, &rdata_size);
579
580 *region = pkg.r;
581 return (r) ? r : (int)pkg.i;
582}
583
584/*
585 * userspace_set_region_sync
586 *
587 * Set the sync status of a given region. This function
588 * must not fail.
589 */
590static void userspace_set_region_sync(struct dm_dirty_log *log,
591 region_t region, int in_sync)
592{
593 int r;
594 struct log_c *lc = log->context;
595 struct {
596 region_t r;
597 int64_t i;
598 } pkg;
599
600 pkg.r = region;
601 pkg.i = (int64_t)in_sync;
602
603 r = userspace_do_request(lc, lc->uuid, DM_ULOG_SET_REGION_SYNC,
604 (char *)&pkg, sizeof(pkg),
605 NULL, NULL);
606
607 /*
608 * It would be nice to be able to report failures.
609 * However, it is easy emough to detect and resolve.
610 */
611 return;
612}
613
614/*
615 * userspace_get_sync_count
616 *
617 * If there is any sort of failure when consulting the server,
618 * we assume that the sync count is zero.
619 *
620 * Returns: sync count on success, 0 on failure
621 */
622static region_t userspace_get_sync_count(struct dm_dirty_log *log)
623{
624 int r;
625 size_t rdata_size;
626 uint64_t sync_count;
627 struct log_c *lc = log->context;
628
629 rdata_size = sizeof(sync_count);
630 r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_SYNC_COUNT,
631 NULL, 0,
632 (char *)&sync_count, &rdata_size);
633
634 if (r)
635 return 0;
636
637 if (sync_count >= lc->region_count)
638 lc->in_sync_hint = lc->region_count;
639
640 return (region_t)sync_count;
641}
642
643/*
644 * userspace_status
645 *
646 * Returns: amount of space consumed
647 */
648static int userspace_status(struct dm_dirty_log *log, status_type_t status_type,
649 char *result, unsigned maxlen)
650{
651 int r = 0;
Jonathan Brassowb8313b62009-09-04 20:40:30 +0100652 char *table_args;
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100653 size_t sz = (size_t)maxlen;
654 struct log_c *lc = log->context;
655
656 switch (status_type) {
657 case STATUSTYPE_INFO:
658 r = userspace_do_request(lc, lc->uuid, DM_ULOG_STATUS_INFO,
659 NULL, 0,
660 result, &sz);
661
662 if (r) {
663 sz = 0;
664 DMEMIT("%s 1 COM_FAILURE", log->type->name);
665 }
666 break;
667 case STATUSTYPE_TABLE:
668 sz = 0;
Geert Uytterhoeven0d03d592009-09-10 23:13:28 +0200669 table_args = strchr(lc->usr_argv_str, ' ');
Jonathan Brassowb8313b62009-09-04 20:40:30 +0100670 BUG_ON(!table_args); /* There will always be a ' ' */
671 table_args++;
672
673 DMEMIT("%s %u %s %s ", log->type->name, lc->usr_argc,
674 lc->uuid, table_args);
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100675 break;
676 }
677 return (r) ? 0 : (int)sz;
678}
679
680/*
681 * userspace_is_remote_recovering
682 *
683 * Returns: 1 if region recovering, 0 otherwise
684 */
685static int userspace_is_remote_recovering(struct dm_dirty_log *log,
686 region_t region)
687{
688 int r;
689 uint64_t region64 = region;
690 struct log_c *lc = log->context;
691 static unsigned long long limit;
692 struct {
693 int64_t is_recovering;
694 uint64_t in_sync_hint;
695 } pkg;
696 size_t rdata_size = sizeof(pkg);
697
698 /*
699 * Once the mirror has been reported to be in-sync,
700 * it will never again ask for recovery work. So,
701 * we can safely say there is not a remote machine
702 * recovering if the device is in-sync. (in_sync_hint
703 * must be reset at resume time.)
704 */
705 if (region < lc->in_sync_hint)
706 return 0;
707 else if (jiffies < limit)
708 return 1;
709
710 limit = jiffies + (HZ / 4);
711 r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_REMOTE_RECOVERING,
712 (char *)&region64, sizeof(region64),
713 (char *)&pkg, &rdata_size);
714 if (r)
715 return 1;
716
717 lc->in_sync_hint = pkg.in_sync_hint;
718
719 return (int)pkg.is_recovering;
720}
721
722static struct dm_dirty_log_type _userspace_type = {
723 .name = "userspace",
724 .module = THIS_MODULE,
725 .ctr = userspace_ctr,
726 .dtr = userspace_dtr,
727 .presuspend = userspace_presuspend,
728 .postsuspend = userspace_postsuspend,
729 .resume = userspace_resume,
730 .get_region_size = userspace_get_region_size,
731 .is_clean = userspace_is_clean,
732 .in_sync = userspace_in_sync,
733 .flush = userspace_flush,
734 .mark_region = userspace_mark_region,
735 .clear_region = userspace_clear_region,
736 .get_resync_work = userspace_get_resync_work,
737 .set_region_sync = userspace_set_region_sync,
738 .get_sync_count = userspace_get_sync_count,
739 .status = userspace_status,
740 .is_remote_recovering = userspace_is_remote_recovering,
741};
742
743static int __init userspace_dirty_log_init(void)
744{
745 int r = 0;
746
747 flush_entry_pool = mempool_create(100, flush_entry_alloc,
748 flush_entry_free, NULL);
749
750 if (!flush_entry_pool) {
751 DMWARN("Unable to create flush_entry_pool: No memory.");
752 return -ENOMEM;
753 }
754
755 r = dm_ulog_tfr_init();
756 if (r) {
757 DMWARN("Unable to initialize userspace log communications");
758 mempool_destroy(flush_entry_pool);
759 return r;
760 }
761
762 r = dm_dirty_log_type_register(&_userspace_type);
763 if (r) {
764 DMWARN("Couldn't register userspace dirty log type");
765 dm_ulog_tfr_exit();
766 mempool_destroy(flush_entry_pool);
767 return r;
768 }
769
Jonathan Brassow86a54a482011-01-13 19:59:52 +0000770 DMINFO("version " DM_LOG_USERSPACE_VSN " loaded");
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100771 return 0;
772}
773
774static void __exit userspace_dirty_log_exit(void)
775{
776 dm_dirty_log_type_unregister(&_userspace_type);
777 dm_ulog_tfr_exit();
778 mempool_destroy(flush_entry_pool);
779
Jonathan Brassow86a54a482011-01-13 19:59:52 +0000780 DMINFO("version " DM_LOG_USERSPACE_VSN " unloaded");
Jonthan Brassowf5db4af2009-06-22 10:12:35 +0100781 return;
782}
783
784module_init(userspace_dirty_log_init);
785module_exit(userspace_dirty_log_exit);
786
787MODULE_DESCRIPTION(DM_NAME " userspace dirty log link");
788MODULE_AUTHOR("Jonathan Brassow <dm-devel@redhat.com>");
789MODULE_LICENSE("GPL");