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Commit | Line | Data |
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f5db4af4 JB |
1 | /* |
2 | * Copyright (C) 2006-2009 Red Hat, Inc. | |
3 | * | |
4 | * This file is released under the LGPL. | |
5 | */ | |
6 | ||
7 | #include <linux/bio.h> | |
5a0e3ad6 | 8 | #include <linux/slab.h> |
f5db4af4 JB |
9 | #include <linux/dm-dirty-log.h> |
10 | #include <linux/device-mapper.h> | |
11 | #include <linux/dm-log-userspace.h> | |
056075c7 | 12 | #include <linux/module.h> |
5066a4df | 13 | #include <linux/workqueue.h> |
f5db4af4 JB |
14 | |
15 | #include "dm-log-userspace-transfer.h" | |
16 | ||
5066a4df | 17 | #define DM_LOG_USERSPACE_VSN "1.3.0" |
86a54a48 | 18 | |
f5db4af4 JB |
19 | struct flush_entry { |
20 | int type; | |
21 | region_t region; | |
22 | struct list_head list; | |
23 | }; | |
24 | ||
085ae065 JB |
25 | /* |
26 | * This limit on the number of mark and clear request is, to a degree, | |
27 | * arbitrary. However, there is some basis for the choice in the limits | |
28 | * imposed on the size of data payload by dm-log-userspace-transfer.c: | |
29 | * dm_consult_userspace(). | |
30 | */ | |
31 | #define MAX_FLUSH_GROUP_COUNT 32 | |
32 | ||
f5db4af4 JB |
33 | struct log_c { |
34 | struct dm_target *ti; | |
5a25f0eb | 35 | struct dm_dev *log_dev; |
f5db4af4 JB |
36 | uint32_t region_size; |
37 | region_t region_count; | |
7ec23d50 | 38 | uint64_t luid; |
f5db4af4 JB |
39 | char uuid[DM_UUID_LEN]; |
40 | ||
41 | char *usr_argv_str; | |
42 | uint32_t usr_argc; | |
43 | ||
44 | /* | |
45 | * in_sync_hint gets set when doing is_remote_recovering. It | |
46 | * represents the first region that needs recovery. IOW, the | |
47 | * first zero bit of sync_bits. This can be useful for to limit | |
48 | * traffic for calls like is_remote_recovering and get_resync_work, | |
49 | * but be take care in its use for anything else. | |
50 | */ | |
51 | uint64_t in_sync_hint; | |
52 | ||
909cc4fb JB |
53 | /* |
54 | * Mark and clear requests are held until a flush is issued | |
55 | * so that we can group, and thereby limit, the amount of | |
56 | * network traffic between kernel and userspace. The 'flush_lock' | |
57 | * is used to protect these lists. | |
58 | */ | |
f5db4af4 | 59 | spinlock_t flush_lock; |
909cc4fb JB |
60 | struct list_head mark_list; |
61 | struct list_head clear_list; | |
5066a4df DZ |
62 | |
63 | /* | |
64 | * Workqueue for flush of clear region requests. | |
65 | */ | |
66 | struct workqueue_struct *dmlog_wq; | |
67 | struct delayed_work flush_log_work; | |
68 | atomic_t sched_flush; | |
69 | ||
70 | /* | |
71 | * Combine userspace flush and mark requests for efficiency. | |
72 | */ | |
73 | uint32_t integrated_flush; | |
f5db4af4 JB |
74 | }; |
75 | ||
76 | static mempool_t *flush_entry_pool; | |
77 | ||
78 | static void *flush_entry_alloc(gfp_t gfp_mask, void *pool_data) | |
79 | { | |
80 | return kmalloc(sizeof(struct flush_entry), gfp_mask); | |
81 | } | |
82 | ||
83 | static void flush_entry_free(void *element, void *pool_data) | |
84 | { | |
85 | kfree(element); | |
86 | } | |
87 | ||
88 | static int userspace_do_request(struct log_c *lc, const char *uuid, | |
89 | int request_type, char *data, size_t data_size, | |
90 | char *rdata, size_t *rdata_size) | |
91 | { | |
92 | int r; | |
93 | ||
94 | /* | |
95 | * If the server isn't there, -ESRCH is returned, | |
96 | * and we must keep trying until the server is | |
97 | * restored. | |
98 | */ | |
99 | retry: | |
7ec23d50 | 100 | r = dm_consult_userspace(uuid, lc->luid, request_type, data, |
f5db4af4 JB |
101 | data_size, rdata, rdata_size); |
102 | ||
103 | if (r != -ESRCH) | |
104 | return r; | |
105 | ||
106 | DMERR(" Userspace log server not found."); | |
107 | while (1) { | |
108 | set_current_state(TASK_INTERRUPTIBLE); | |
109 | schedule_timeout(2*HZ); | |
110 | DMWARN("Attempting to contact userspace log server..."); | |
7ec23d50 JB |
111 | r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_CTR, |
112 | lc->usr_argv_str, | |
f5db4af4 JB |
113 | strlen(lc->usr_argv_str) + 1, |
114 | NULL, NULL); | |
115 | if (!r) | |
116 | break; | |
117 | } | |
118 | DMINFO("Reconnected to userspace log server... DM_ULOG_CTR complete"); | |
7ec23d50 | 119 | r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_RESUME, NULL, |
f5db4af4 JB |
120 | 0, NULL, NULL); |
121 | if (!r) | |
122 | goto retry; | |
123 | ||
124 | DMERR("Error trying to resume userspace log: %d", r); | |
125 | ||
126 | return -ESRCH; | |
127 | } | |
128 | ||
129 | static int build_constructor_string(struct dm_target *ti, | |
130 | unsigned argc, char **argv, | |
131 | char **ctr_str) | |
132 | { | |
133 | int i, str_size; | |
134 | char *str = NULL; | |
135 | ||
136 | *ctr_str = NULL; | |
137 | ||
5066a4df DZ |
138 | /* |
139 | * Determine overall size of the string. | |
140 | */ | |
f5db4af4 JB |
141 | for (i = 0, str_size = 0; i < argc; i++) |
142 | str_size += strlen(argv[i]) + 1; /* +1 for space between args */ | |
143 | ||
144 | str_size += 20; /* Max number of chars in a printed u64 number */ | |
145 | ||
146 | str = kzalloc(str_size, GFP_KERNEL); | |
147 | if (!str) { | |
148 | DMWARN("Unable to allocate memory for constructor string"); | |
149 | return -ENOMEM; | |
150 | } | |
151 | ||
b8313b6d JB |
152 | str_size = sprintf(str, "%llu", (unsigned long long)ti->len); |
153 | for (i = 0; i < argc; i++) | |
154 | str_size += sprintf(str + str_size, " %s", argv[i]); | |
f5db4af4 JB |
155 | |
156 | *ctr_str = str; | |
157 | return str_size; | |
158 | } | |
159 | ||
5066a4df DZ |
160 | static void do_flush(struct work_struct *work) |
161 | { | |
162 | int r; | |
163 | struct log_c *lc = container_of(work, struct log_c, flush_log_work.work); | |
164 | ||
165 | atomic_set(&lc->sched_flush, 0); | |
166 | ||
167 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, NULL, 0, NULL, NULL); | |
168 | ||
169 | if (r) | |
170 | dm_table_event(lc->ti->table); | |
171 | } | |
172 | ||
f5db4af4 JB |
173 | /* |
174 | * userspace_ctr | |
175 | * | |
176 | * argv contains: | |
5066a4df DZ |
177 | * <UUID> [integrated_flush] <other args> |
178 | * Where 'other args' are the userspace implementation-specific log | |
179 | * arguments. | |
180 | * | |
181 | * Example: | |
182 | * <UUID> [integrated_flush] clustered-disk <arg count> <log dev> | |
183 | * <region_size> [[no]sync] | |
184 | * | |
185 | * This module strips off the <UUID> and uses it for identification | |
186 | * purposes when communicating with userspace about a log. | |
f5db4af4 | 187 | * |
5066a4df DZ |
188 | * If integrated_flush is defined, the kernel combines flush |
189 | * and mark requests. | |
190 | * | |
191 | * The rest of the line, beginning with 'clustered-disk', is passed | |
192 | * to the userspace ctr function. | |
f5db4af4 JB |
193 | */ |
194 | static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, | |
195 | unsigned argc, char **argv) | |
196 | { | |
197 | int r = 0; | |
198 | int str_size; | |
199 | char *ctr_str = NULL; | |
200 | struct log_c *lc = NULL; | |
201 | uint64_t rdata; | |
202 | size_t rdata_size = sizeof(rdata); | |
5a25f0eb JB |
203 | char *devices_rdata = NULL; |
204 | size_t devices_rdata_size = DM_NAME_LEN; | |
f5db4af4 JB |
205 | |
206 | if (argc < 3) { | |
207 | DMWARN("Too few arguments to userspace dirty log"); | |
208 | return -EINVAL; | |
209 | } | |
210 | ||
5a25f0eb | 211 | lc = kzalloc(sizeof(*lc), GFP_KERNEL); |
f5db4af4 JB |
212 | if (!lc) { |
213 | DMWARN("Unable to allocate userspace log context."); | |
214 | return -ENOMEM; | |
215 | } | |
216 | ||
7ec23d50 | 217 | /* The ptr value is sufficient for local unique id */ |
bca915aa | 218 | lc->luid = (unsigned long)lc; |
7ec23d50 | 219 | |
f5db4af4 JB |
220 | lc->ti = ti; |
221 | ||
222 | if (strlen(argv[0]) > (DM_UUID_LEN - 1)) { | |
223 | DMWARN("UUID argument too long."); | |
224 | kfree(lc); | |
225 | return -EINVAL; | |
226 | } | |
227 | ||
5066a4df DZ |
228 | lc->usr_argc = argc; |
229 | ||
f5db4af4 | 230 | strncpy(lc->uuid, argv[0], DM_UUID_LEN); |
5066a4df DZ |
231 | argc--; |
232 | argv++; | |
f5db4af4 | 233 | spin_lock_init(&lc->flush_lock); |
909cc4fb JB |
234 | INIT_LIST_HEAD(&lc->mark_list); |
235 | INIT_LIST_HEAD(&lc->clear_list); | |
f5db4af4 | 236 | |
5066a4df DZ |
237 | if (!strcasecmp(argv[0], "integrated_flush")) { |
238 | lc->integrated_flush = 1; | |
239 | argc--; | |
240 | argv++; | |
241 | } | |
242 | ||
243 | str_size = build_constructor_string(ti, argc, argv, &ctr_str); | |
f5db4af4 JB |
244 | if (str_size < 0) { |
245 | kfree(lc); | |
246 | return str_size; | |
247 | } | |
248 | ||
5a25f0eb JB |
249 | devices_rdata = kzalloc(devices_rdata_size, GFP_KERNEL); |
250 | if (!devices_rdata) { | |
251 | DMERR("Failed to allocate memory for device information"); | |
252 | r = -ENOMEM; | |
253 | goto out; | |
254 | } | |
255 | ||
256 | /* | |
257 | * Send table string and get back any opened device. | |
258 | */ | |
7ec23d50 | 259 | r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR, |
5a25f0eb JB |
260 | ctr_str, str_size, |
261 | devices_rdata, &devices_rdata_size); | |
f5db4af4 | 262 | |
4a038677 JB |
263 | if (r < 0) { |
264 | if (r == -ESRCH) | |
265 | DMERR("Userspace log server not found"); | |
266 | else | |
267 | DMERR("Userspace log server failed to create log"); | |
f5db4af4 JB |
268 | goto out; |
269 | } | |
270 | ||
271 | /* Since the region size does not change, get it now */ | |
272 | rdata_size = sizeof(rdata); | |
7ec23d50 | 273 | r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_GET_REGION_SIZE, |
f5db4af4 JB |
274 | NULL, 0, (char *)&rdata, &rdata_size); |
275 | ||
276 | if (r) { | |
277 | DMERR("Failed to get region size of dirty log"); | |
278 | goto out; | |
279 | } | |
280 | ||
281 | lc->region_size = (uint32_t)rdata; | |
282 | lc->region_count = dm_sector_div_up(ti->len, lc->region_size); | |
283 | ||
5a25f0eb JB |
284 | if (devices_rdata_size) { |
285 | if (devices_rdata[devices_rdata_size - 1] != '\0') { | |
286 | DMERR("DM_ULOG_CTR device return string not properly terminated"); | |
287 | r = -EINVAL; | |
288 | goto out; | |
289 | } | |
290 | r = dm_get_device(ti, devices_rdata, | |
291 | dm_table_get_mode(ti->table), &lc->log_dev); | |
292 | if (r) | |
293 | DMERR("Failed to register %s with device-mapper", | |
294 | devices_rdata); | |
295 | } | |
5066a4df DZ |
296 | |
297 | if (lc->integrated_flush) { | |
298 | lc->dmlog_wq = alloc_workqueue("dmlogd", WQ_MEM_RECLAIM, 0); | |
299 | if (!lc->dmlog_wq) { | |
300 | DMERR("couldn't start dmlogd"); | |
301 | r = -ENOMEM; | |
302 | goto out; | |
303 | } | |
304 | ||
305 | INIT_DELAYED_WORK(&lc->flush_log_work, do_flush); | |
306 | atomic_set(&lc->sched_flush, 0); | |
307 | } | |
308 | ||
f5db4af4 | 309 | out: |
5a25f0eb | 310 | kfree(devices_rdata); |
f5db4af4 JB |
311 | if (r) { |
312 | kfree(lc); | |
313 | kfree(ctr_str); | |
314 | } else { | |
315 | lc->usr_argv_str = ctr_str; | |
f5db4af4 JB |
316 | log->context = lc; |
317 | } | |
318 | ||
319 | return r; | |
320 | } | |
321 | ||
322 | static void userspace_dtr(struct dm_dirty_log *log) | |
323 | { | |
f5db4af4 JB |
324 | struct log_c *lc = log->context; |
325 | ||
5066a4df DZ |
326 | if (lc->integrated_flush) { |
327 | /* flush workqueue */ | |
328 | if (atomic_read(&lc->sched_flush)) | |
329 | flush_delayed_work(&lc->flush_log_work); | |
330 | ||
331 | destroy_workqueue(lc->dmlog_wq); | |
332 | } | |
333 | ||
4a038677 | 334 | (void) dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR, |
5066a4df | 335 | NULL, 0, NULL, NULL); |
f5db4af4 | 336 | |
5a25f0eb JB |
337 | if (lc->log_dev) |
338 | dm_put_device(lc->ti, lc->log_dev); | |
339 | ||
f5db4af4 JB |
340 | kfree(lc->usr_argv_str); |
341 | kfree(lc); | |
342 | ||
343 | return; | |
344 | } | |
345 | ||
346 | static int userspace_presuspend(struct dm_dirty_log *log) | |
347 | { | |
348 | int r; | |
349 | struct log_c *lc = log->context; | |
350 | ||
7ec23d50 | 351 | r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_PRESUSPEND, |
5066a4df | 352 | NULL, 0, NULL, NULL); |
f5db4af4 JB |
353 | |
354 | return r; | |
355 | } | |
356 | ||
357 | static int userspace_postsuspend(struct dm_dirty_log *log) | |
358 | { | |
359 | int r; | |
360 | struct log_c *lc = log->context; | |
361 | ||
5066a4df DZ |
362 | /* |
363 | * Run planned flush earlier. | |
364 | */ | |
365 | if (lc->integrated_flush && atomic_read(&lc->sched_flush)) | |
366 | flush_delayed_work(&lc->flush_log_work); | |
367 | ||
7ec23d50 | 368 | r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_POSTSUSPEND, |
5066a4df | 369 | NULL, 0, NULL, NULL); |
f5db4af4 JB |
370 | |
371 | return r; | |
372 | } | |
373 | ||
374 | static int userspace_resume(struct dm_dirty_log *log) | |
375 | { | |
376 | int r; | |
377 | struct log_c *lc = log->context; | |
378 | ||
379 | lc->in_sync_hint = 0; | |
7ec23d50 | 380 | r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_RESUME, |
5066a4df | 381 | NULL, 0, NULL, NULL); |
f5db4af4 JB |
382 | |
383 | return r; | |
384 | } | |
385 | ||
386 | static uint32_t userspace_get_region_size(struct dm_dirty_log *log) | |
387 | { | |
388 | struct log_c *lc = log->context; | |
389 | ||
390 | return lc->region_size; | |
391 | } | |
392 | ||
393 | /* | |
394 | * userspace_is_clean | |
395 | * | |
396 | * Check whether a region is clean. If there is any sort of | |
397 | * failure when consulting the server, we return not clean. | |
398 | * | |
399 | * Returns: 1 if clean, 0 otherwise | |
400 | */ | |
401 | static int userspace_is_clean(struct dm_dirty_log *log, region_t region) | |
402 | { | |
403 | int r; | |
404 | uint64_t region64 = (uint64_t)region; | |
405 | int64_t is_clean; | |
406 | size_t rdata_size; | |
407 | struct log_c *lc = log->context; | |
408 | ||
409 | rdata_size = sizeof(is_clean); | |
410 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_CLEAN, | |
411 | (char *)®ion64, sizeof(region64), | |
412 | (char *)&is_clean, &rdata_size); | |
413 | ||
414 | return (r) ? 0 : (int)is_clean; | |
415 | } | |
416 | ||
417 | /* | |
418 | * userspace_in_sync | |
419 | * | |
420 | * Check if the region is in-sync. If there is any sort | |
421 | * of failure when consulting the server, we assume that | |
422 | * the region is not in sync. | |
423 | * | |
424 | * If 'can_block' is set, return immediately | |
425 | * | |
426 | * Returns: 1 if in-sync, 0 if not-in-sync, -EWOULDBLOCK | |
427 | */ | |
428 | static int userspace_in_sync(struct dm_dirty_log *log, region_t region, | |
429 | int can_block) | |
430 | { | |
431 | int r; | |
432 | uint64_t region64 = region; | |
433 | int64_t in_sync; | |
434 | size_t rdata_size; | |
435 | struct log_c *lc = log->context; | |
436 | ||
437 | /* | |
438 | * We can never respond directly - even if in_sync_hint is | |
439 | * set. This is because another machine could see a device | |
440 | * failure and mark the region out-of-sync. If we don't go | |
441 | * to userspace to ask, we might think the region is in-sync | |
442 | * and allow a read to pick up data that is stale. (This is | |
443 | * very unlikely if a device actually fails; but it is very | |
444 | * likely if a connection to one device from one machine fails.) | |
445 | * | |
446 | * There still might be a problem if the mirror caches the region | |
447 | * state as in-sync... but then this call would not be made. So, | |
448 | * that is a mirror problem. | |
449 | */ | |
450 | if (!can_block) | |
451 | return -EWOULDBLOCK; | |
452 | ||
453 | rdata_size = sizeof(in_sync); | |
454 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_IN_SYNC, | |
455 | (char *)®ion64, sizeof(region64), | |
456 | (char *)&in_sync, &rdata_size); | |
457 | return (r) ? 0 : (int)in_sync; | |
458 | } | |
459 | ||
085ae065 JB |
460 | static int flush_one_by_one(struct log_c *lc, struct list_head *flush_list) |
461 | { | |
462 | int r = 0; | |
463 | struct flush_entry *fe; | |
464 | ||
465 | list_for_each_entry(fe, flush_list, list) { | |
466 | r = userspace_do_request(lc, lc->uuid, fe->type, | |
467 | (char *)&fe->region, | |
468 | sizeof(fe->region), | |
469 | NULL, NULL); | |
470 | if (r) | |
471 | break; | |
472 | } | |
473 | ||
474 | return r; | |
475 | } | |
476 | ||
5066a4df DZ |
477 | static int flush_by_group(struct log_c *lc, struct list_head *flush_list, |
478 | int flush_with_payload) | |
085ae065 JB |
479 | { |
480 | int r = 0; | |
481 | int count; | |
482 | uint32_t type = 0; | |
483 | struct flush_entry *fe, *tmp_fe; | |
484 | LIST_HEAD(tmp_list); | |
485 | uint64_t group[MAX_FLUSH_GROUP_COUNT]; | |
486 | ||
487 | /* | |
488 | * Group process the requests | |
489 | */ | |
490 | while (!list_empty(flush_list)) { | |
491 | count = 0; | |
492 | ||
493 | list_for_each_entry_safe(fe, tmp_fe, flush_list, list) { | |
494 | group[count] = fe->region; | |
495 | count++; | |
496 | ||
6c9b27ab | 497 | list_move(&fe->list, &tmp_list); |
085ae065 JB |
498 | |
499 | type = fe->type; | |
500 | if (count >= MAX_FLUSH_GROUP_COUNT) | |
501 | break; | |
502 | } | |
503 | ||
5066a4df DZ |
504 | if (flush_with_payload) { |
505 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, | |
506 | (char *)(group), | |
507 | count * sizeof(uint64_t), | |
508 | NULL, NULL); | |
509 | /* | |
510 | * Integrated flush failed. | |
511 | */ | |
512 | if (r) | |
513 | break; | |
514 | } else { | |
515 | r = userspace_do_request(lc, lc->uuid, type, | |
516 | (char *)(group), | |
517 | count * sizeof(uint64_t), | |
518 | NULL, NULL); | |
519 | if (r) { | |
520 | /* | |
521 | * Group send failed. Attempt one-by-one. | |
522 | */ | |
523 | list_splice_init(&tmp_list, flush_list); | |
524 | r = flush_one_by_one(lc, flush_list); | |
525 | break; | |
526 | } | |
085ae065 JB |
527 | } |
528 | } | |
529 | ||
530 | /* | |
531 | * Must collect flush_entrys that were successfully processed | |
532 | * as a group so that they will be free'd by the caller. | |
533 | */ | |
534 | list_splice_init(&tmp_list, flush_list); | |
535 | ||
536 | return r; | |
537 | } | |
538 | ||
f5db4af4 JB |
539 | /* |
540 | * userspace_flush | |
541 | * | |
542 | * This function is ok to block. | |
543 | * The flush happens in two stages. First, it sends all | |
544 | * clear/mark requests that are on the list. Then it | |
545 | * tells the server to commit them. This gives the | |
546 | * server a chance to optimise the commit, instead of | |
547 | * doing it for every request. | |
548 | * | |
549 | * Additionally, we could implement another thread that | |
550 | * sends the requests up to the server - reducing the | |
551 | * load on flush. Then the flush would have less in | |
552 | * the list and be responsible for the finishing commit. | |
553 | * | |
554 | * Returns: 0 on success, < 0 on failure | |
555 | */ | |
556 | static int userspace_flush(struct dm_dirty_log *log) | |
557 | { | |
558 | int r = 0; | |
559 | unsigned long flags; | |
560 | struct log_c *lc = log->context; | |
909cc4fb JB |
561 | LIST_HEAD(mark_list); |
562 | LIST_HEAD(clear_list); | |
5066a4df DZ |
563 | int mark_list_is_empty; |
564 | int clear_list_is_empty; | |
f5db4af4 JB |
565 | struct flush_entry *fe, *tmp_fe; |
566 | ||
567 | spin_lock_irqsave(&lc->flush_lock, flags); | |
909cc4fb JB |
568 | list_splice_init(&lc->mark_list, &mark_list); |
569 | list_splice_init(&lc->clear_list, &clear_list); | |
f5db4af4 JB |
570 | spin_unlock_irqrestore(&lc->flush_lock, flags); |
571 | ||
5066a4df DZ |
572 | mark_list_is_empty = list_empty(&mark_list); |
573 | clear_list_is_empty = list_empty(&clear_list); | |
574 | ||
575 | if (mark_list_is_empty && clear_list_is_empty) | |
f5db4af4 JB |
576 | return 0; |
577 | ||
5066a4df | 578 | r = flush_by_group(lc, &clear_list, 0); |
085ae065 | 579 | if (r) |
5066a4df DZ |
580 | goto out; |
581 | ||
582 | if (!lc->integrated_flush) { | |
583 | r = flush_by_group(lc, &mark_list, 0); | |
584 | if (r) | |
585 | goto out; | |
586 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, | |
587 | NULL, 0, NULL, NULL); | |
588 | goto out; | |
589 | } | |
909cc4fb | 590 | |
5066a4df DZ |
591 | /* |
592 | * Send integrated flush request with mark_list as payload. | |
593 | */ | |
594 | r = flush_by_group(lc, &mark_list, 1); | |
085ae065 | 595 | if (r) |
5066a4df | 596 | goto out; |
f5db4af4 | 597 | |
5066a4df DZ |
598 | if (mark_list_is_empty && !atomic_read(&lc->sched_flush)) { |
599 | /* | |
600 | * When there are only clear region requests, | |
601 | * we schedule a flush in the future. | |
602 | */ | |
603 | queue_delayed_work(lc->dmlog_wq, &lc->flush_log_work, 3 * HZ); | |
604 | atomic_set(&lc->sched_flush, 1); | |
605 | } else { | |
606 | /* | |
607 | * Cancel pending flush because we | |
608 | * have already flushed in mark_region. | |
609 | */ | |
610 | cancel_delayed_work(&lc->flush_log_work); | |
611 | atomic_set(&lc->sched_flush, 0); | |
612 | } | |
f5db4af4 | 613 | |
5066a4df | 614 | out: |
f5db4af4 | 615 | /* |
5066a4df | 616 | * We can safely remove these entries, even after failure. |
f5db4af4 JB |
617 | * Calling code will receive an error and will know that |
618 | * the log facility has failed. | |
619 | */ | |
909cc4fb JB |
620 | list_for_each_entry_safe(fe, tmp_fe, &mark_list, list) { |
621 | list_del(&fe->list); | |
622 | mempool_free(fe, flush_entry_pool); | |
623 | } | |
624 | list_for_each_entry_safe(fe, tmp_fe, &clear_list, list) { | |
f5db4af4 JB |
625 | list_del(&fe->list); |
626 | mempool_free(fe, flush_entry_pool); | |
627 | } | |
628 | ||
629 | if (r) | |
630 | dm_table_event(lc->ti->table); | |
631 | ||
632 | return r; | |
633 | } | |
634 | ||
635 | /* | |
636 | * userspace_mark_region | |
637 | * | |
638 | * This function should avoid blocking unless absolutely required. | |
639 | * (Memory allocation is valid for blocking.) | |
640 | */ | |
641 | static void userspace_mark_region(struct dm_dirty_log *log, region_t region) | |
642 | { | |
643 | unsigned long flags; | |
644 | struct log_c *lc = log->context; | |
645 | struct flush_entry *fe; | |
646 | ||
647 | /* Wait for an allocation, but _never_ fail */ | |
648 | fe = mempool_alloc(flush_entry_pool, GFP_NOIO); | |
649 | BUG_ON(!fe); | |
650 | ||
651 | spin_lock_irqsave(&lc->flush_lock, flags); | |
652 | fe->type = DM_ULOG_MARK_REGION; | |
653 | fe->region = region; | |
909cc4fb | 654 | list_add(&fe->list, &lc->mark_list); |
f5db4af4 JB |
655 | spin_unlock_irqrestore(&lc->flush_lock, flags); |
656 | ||
657 | return; | |
658 | } | |
659 | ||
660 | /* | |
661 | * userspace_clear_region | |
662 | * | |
663 | * This function must not block. | |
664 | * So, the alloc can't block. In the worst case, it is ok to | |
665 | * fail. It would simply mean we can't clear the region. | |
666 | * Does nothing to current sync context, but does mean | |
667 | * the region will be re-sync'ed on a reload of the mirror | |
668 | * even though it is in-sync. | |
669 | */ | |
670 | static void userspace_clear_region(struct dm_dirty_log *log, region_t region) | |
671 | { | |
672 | unsigned long flags; | |
673 | struct log_c *lc = log->context; | |
674 | struct flush_entry *fe; | |
675 | ||
676 | /* | |
677 | * If we fail to allocate, we skip the clearing of | |
678 | * the region. This doesn't hurt us in any way, except | |
679 | * to cause the region to be resync'ed when the | |
680 | * device is activated next time. | |
681 | */ | |
682 | fe = mempool_alloc(flush_entry_pool, GFP_ATOMIC); | |
683 | if (!fe) { | |
684 | DMERR("Failed to allocate memory to clear region."); | |
685 | return; | |
686 | } | |
687 | ||
688 | spin_lock_irqsave(&lc->flush_lock, flags); | |
689 | fe->type = DM_ULOG_CLEAR_REGION; | |
690 | fe->region = region; | |
909cc4fb | 691 | list_add(&fe->list, &lc->clear_list); |
f5db4af4 JB |
692 | spin_unlock_irqrestore(&lc->flush_lock, flags); |
693 | ||
694 | return; | |
695 | } | |
696 | ||
697 | /* | |
698 | * userspace_get_resync_work | |
699 | * | |
700 | * Get a region that needs recovery. It is valid to return | |
701 | * an error for this function. | |
702 | * | |
703 | * Returns: 1 if region filled, 0 if no work, <0 on error | |
704 | */ | |
705 | static int userspace_get_resync_work(struct dm_dirty_log *log, region_t *region) | |
706 | { | |
707 | int r; | |
708 | size_t rdata_size; | |
709 | struct log_c *lc = log->context; | |
710 | struct { | |
711 | int64_t i; /* 64-bit for mix arch compatibility */ | |
712 | region_t r; | |
713 | } pkg; | |
714 | ||
715 | if (lc->in_sync_hint >= lc->region_count) | |
716 | return 0; | |
717 | ||
718 | rdata_size = sizeof(pkg); | |
719 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_RESYNC_WORK, | |
5066a4df | 720 | NULL, 0, (char *)&pkg, &rdata_size); |
f5db4af4 JB |
721 | |
722 | *region = pkg.r; | |
723 | return (r) ? r : (int)pkg.i; | |
724 | } | |
725 | ||
726 | /* | |
727 | * userspace_set_region_sync | |
728 | * | |
729 | * Set the sync status of a given region. This function | |
730 | * must not fail. | |
731 | */ | |
732 | static void userspace_set_region_sync(struct dm_dirty_log *log, | |
733 | region_t region, int in_sync) | |
734 | { | |
735 | int r; | |
736 | struct log_c *lc = log->context; | |
737 | struct { | |
738 | region_t r; | |
739 | int64_t i; | |
740 | } pkg; | |
741 | ||
742 | pkg.r = region; | |
743 | pkg.i = (int64_t)in_sync; | |
744 | ||
745 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_SET_REGION_SYNC, | |
5066a4df | 746 | (char *)&pkg, sizeof(pkg), NULL, NULL); |
f5db4af4 JB |
747 | |
748 | /* | |
749 | * It would be nice to be able to report failures. | |
750 | * However, it is easy emough to detect and resolve. | |
751 | */ | |
752 | return; | |
753 | } | |
754 | ||
755 | /* | |
756 | * userspace_get_sync_count | |
757 | * | |
758 | * If there is any sort of failure when consulting the server, | |
759 | * we assume that the sync count is zero. | |
760 | * | |
761 | * Returns: sync count on success, 0 on failure | |
762 | */ | |
763 | static region_t userspace_get_sync_count(struct dm_dirty_log *log) | |
764 | { | |
765 | int r; | |
766 | size_t rdata_size; | |
767 | uint64_t sync_count; | |
768 | struct log_c *lc = log->context; | |
769 | ||
770 | rdata_size = sizeof(sync_count); | |
771 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_SYNC_COUNT, | |
5066a4df | 772 | NULL, 0, (char *)&sync_count, &rdata_size); |
f5db4af4 JB |
773 | |
774 | if (r) | |
775 | return 0; | |
776 | ||
777 | if (sync_count >= lc->region_count) | |
778 | lc->in_sync_hint = lc->region_count; | |
779 | ||
780 | return (region_t)sync_count; | |
781 | } | |
782 | ||
783 | /* | |
784 | * userspace_status | |
785 | * | |
786 | * Returns: amount of space consumed | |
787 | */ | |
788 | static int userspace_status(struct dm_dirty_log *log, status_type_t status_type, | |
789 | char *result, unsigned maxlen) | |
790 | { | |
791 | int r = 0; | |
b8313b6d | 792 | char *table_args; |
f5db4af4 JB |
793 | size_t sz = (size_t)maxlen; |
794 | struct log_c *lc = log->context; | |
795 | ||
796 | switch (status_type) { | |
797 | case STATUSTYPE_INFO: | |
798 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_STATUS_INFO, | |
5066a4df | 799 | NULL, 0, result, &sz); |
f5db4af4 JB |
800 | |
801 | if (r) { | |
802 | sz = 0; | |
803 | DMEMIT("%s 1 COM_FAILURE", log->type->name); | |
804 | } | |
805 | break; | |
806 | case STATUSTYPE_TABLE: | |
807 | sz = 0; | |
0d03d59d | 808 | table_args = strchr(lc->usr_argv_str, ' '); |
b8313b6d JB |
809 | BUG_ON(!table_args); /* There will always be a ' ' */ |
810 | table_args++; | |
811 | ||
5066a4df DZ |
812 | DMEMIT("%s %u %s ", log->type->name, lc->usr_argc, lc->uuid); |
813 | if (lc->integrated_flush) | |
814 | DMEMIT("integrated_flush "); | |
815 | DMEMIT("%s ", table_args); | |
f5db4af4 JB |
816 | break; |
817 | } | |
818 | return (r) ? 0 : (int)sz; | |
819 | } | |
820 | ||
821 | /* | |
822 | * userspace_is_remote_recovering | |
823 | * | |
824 | * Returns: 1 if region recovering, 0 otherwise | |
825 | */ | |
826 | static int userspace_is_remote_recovering(struct dm_dirty_log *log, | |
827 | region_t region) | |
828 | { | |
829 | int r; | |
830 | uint64_t region64 = region; | |
831 | struct log_c *lc = log->context; | |
832 | static unsigned long long limit; | |
833 | struct { | |
834 | int64_t is_recovering; | |
835 | uint64_t in_sync_hint; | |
836 | } pkg; | |
837 | size_t rdata_size = sizeof(pkg); | |
838 | ||
839 | /* | |
840 | * Once the mirror has been reported to be in-sync, | |
841 | * it will never again ask for recovery work. So, | |
842 | * we can safely say there is not a remote machine | |
843 | * recovering if the device is in-sync. (in_sync_hint | |
844 | * must be reset at resume time.) | |
845 | */ | |
846 | if (region < lc->in_sync_hint) | |
847 | return 0; | |
848 | else if (jiffies < limit) | |
849 | return 1; | |
850 | ||
851 | limit = jiffies + (HZ / 4); | |
852 | r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_REMOTE_RECOVERING, | |
853 | (char *)®ion64, sizeof(region64), | |
854 | (char *)&pkg, &rdata_size); | |
855 | if (r) | |
856 | return 1; | |
857 | ||
858 | lc->in_sync_hint = pkg.in_sync_hint; | |
859 | ||
860 | return (int)pkg.is_recovering; | |
861 | } | |
862 | ||
863 | static struct dm_dirty_log_type _userspace_type = { | |
864 | .name = "userspace", | |
865 | .module = THIS_MODULE, | |
866 | .ctr = userspace_ctr, | |
867 | .dtr = userspace_dtr, | |
868 | .presuspend = userspace_presuspend, | |
869 | .postsuspend = userspace_postsuspend, | |
870 | .resume = userspace_resume, | |
871 | .get_region_size = userspace_get_region_size, | |
872 | .is_clean = userspace_is_clean, | |
873 | .in_sync = userspace_in_sync, | |
874 | .flush = userspace_flush, | |
875 | .mark_region = userspace_mark_region, | |
876 | .clear_region = userspace_clear_region, | |
877 | .get_resync_work = userspace_get_resync_work, | |
878 | .set_region_sync = userspace_set_region_sync, | |
879 | .get_sync_count = userspace_get_sync_count, | |
880 | .status = userspace_status, | |
881 | .is_remote_recovering = userspace_is_remote_recovering, | |
882 | }; | |
883 | ||
884 | static int __init userspace_dirty_log_init(void) | |
885 | { | |
886 | int r = 0; | |
887 | ||
888 | flush_entry_pool = mempool_create(100, flush_entry_alloc, | |
889 | flush_entry_free, NULL); | |
890 | ||
891 | if (!flush_entry_pool) { | |
892 | DMWARN("Unable to create flush_entry_pool: No memory."); | |
893 | return -ENOMEM; | |
894 | } | |
895 | ||
896 | r = dm_ulog_tfr_init(); | |
897 | if (r) { | |
898 | DMWARN("Unable to initialize userspace log communications"); | |
899 | mempool_destroy(flush_entry_pool); | |
900 | return r; | |
901 | } | |
902 | ||
903 | r = dm_dirty_log_type_register(&_userspace_type); | |
904 | if (r) { | |
905 | DMWARN("Couldn't register userspace dirty log type"); | |
906 | dm_ulog_tfr_exit(); | |
907 | mempool_destroy(flush_entry_pool); | |
908 | return r; | |
909 | } | |
910 | ||
86a54a48 | 911 | DMINFO("version " DM_LOG_USERSPACE_VSN " loaded"); |
f5db4af4 JB |
912 | return 0; |
913 | } | |
914 | ||
915 | static void __exit userspace_dirty_log_exit(void) | |
916 | { | |
917 | dm_dirty_log_type_unregister(&_userspace_type); | |
918 | dm_ulog_tfr_exit(); | |
919 | mempool_destroy(flush_entry_pool); | |
920 | ||
86a54a48 | 921 | DMINFO("version " DM_LOG_USERSPACE_VSN " unloaded"); |
f5db4af4 JB |
922 | return; |
923 | } | |
924 | ||
925 | module_init(userspace_dirty_log_init); | |
926 | module_exit(userspace_dirty_log_exit); | |
927 | ||
928 | MODULE_DESCRIPTION(DM_NAME " userspace dirty log link"); | |
929 | MODULE_AUTHOR("Jonathan Brassow <dm-devel@redhat.com>"); | |
930 | MODULE_LICENSE("GPL"); |