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1/*
2 drbd_worker.c
3
4 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
5
6 Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
7 Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
8 Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
9
10 drbd is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
13 any later version.
14
15 drbd is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with drbd; see the file COPYING. If not, write to
22 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
23
24 */
25
26#include <linux/module.h>
27#include <linux/drbd.h>
28#include <linux/sched.h>
29#include <linux/wait.h>
30#include <linux/mm.h>
31#include <linux/memcontrol.h>
32#include <linux/mm_inline.h>
33#include <linux/slab.h>
34#include <linux/random.h>
35#include <linux/string.h>
36#include <linux/scatterlist.h>
37
38#include "drbd_int.h"
39#include "drbd_req.h"
40
41static int w_make_ov_request(struct drbd_conf *mdev, struct drbd_work *w, int cancel);
42static int w_make_resync_request(struct drbd_conf *mdev,
43 struct drbd_work *w, int cancel);
44
45
46
47/* endio handlers:
48 * drbd_md_io_complete (defined here)
49 * drbd_endio_pri (defined here)
50 * drbd_endio_sec (defined here)
51 * bm_async_io_complete (defined in drbd_bitmap.c)
52 *
53 * For all these callbacks, note the following:
54 * The callbacks will be called in irq context by the IDE drivers,
55 * and in Softirqs/Tasklets/BH context by the SCSI drivers.
56 * Try to get the locking right :)
57 *
58 */
59
60
61/* About the global_state_lock
62 Each state transition on an device holds a read lock. In case we have
63 to evaluate the sync after dependencies, we grab a write lock, because
64 we need stable states on all devices for that. */
65rwlock_t global_state_lock;
66
67/* used for synchronous meta data and bitmap IO
68 * submitted by drbd_md_sync_page_io()
69 */
70void drbd_md_io_complete(struct bio *bio, int error)
71{
72 struct drbd_md_io *md_io;
73
74 md_io = (struct drbd_md_io *)bio->bi_private;
75 md_io->error = error;
76
77 complete(&md_io->event);
78}
79
80/* reads on behalf of the partner,
81 * "submitted" by the receiver
82 */
83void drbd_endio_read_sec_final(struct drbd_epoch_entry *e) __releases(local)
84{
85 unsigned long flags = 0;
86 struct drbd_conf *mdev = e->mdev;
87
88 D_ASSERT(e->block_id != ID_VACANT);
89
90 spin_lock_irqsave(&mdev->req_lock, flags);
91 mdev->read_cnt += e->size >> 9;
92 list_del(&e->w.list);
93 if (list_empty(&mdev->read_ee))
94 wake_up(&mdev->ee_wait);
95 if (test_bit(__EE_WAS_ERROR, &e->flags))
96 __drbd_chk_io_error(mdev, false);
97 spin_unlock_irqrestore(&mdev->req_lock, flags);
98
99 drbd_queue_work(&mdev->data.work, &e->w);
100 put_ldev(mdev);
101}
102
103/* writes on behalf of the partner, or resync writes,
104 * "submitted" by the receiver, final stage. */
105static void drbd_endio_write_sec_final(struct drbd_epoch_entry *e) __releases(local)
106{
107 unsigned long flags = 0;
108 struct drbd_conf *mdev = e->mdev;
109 sector_t e_sector;
110 int do_wake;
111 int is_syncer_req;
112 int do_al_complete_io;
113
114 D_ASSERT(e->block_id != ID_VACANT);
115
116 /* after we moved e to done_ee,
117 * we may no longer access it,
118 * it may be freed/reused already!
119 * (as soon as we release the req_lock) */
120 e_sector = e->sector;
121 do_al_complete_io = e->flags & EE_CALL_AL_COMPLETE_IO;
122 is_syncer_req = is_syncer_block_id(e->block_id);
123
124 spin_lock_irqsave(&mdev->req_lock, flags);
125 mdev->writ_cnt += e->size >> 9;
126 list_del(&e->w.list); /* has been on active_ee or sync_ee */
127 list_add_tail(&e->w.list, &mdev->done_ee);
128
129 /* No hlist_del_init(&e->collision) here, we did not send the Ack yet,
130 * neither did we wake possibly waiting conflicting requests.
131 * done from "drbd_process_done_ee" within the appropriate w.cb
132 * (e_end_block/e_end_resync_block) or from _drbd_clear_done_ee */
133
134 do_wake = is_syncer_req
135 ? list_empty(&mdev->sync_ee)
136 : list_empty(&mdev->active_ee);
137
138 if (test_bit(__EE_WAS_ERROR, &e->flags))
139 __drbd_chk_io_error(mdev, false);
140 spin_unlock_irqrestore(&mdev->req_lock, flags);
141
142 if (is_syncer_req)
143 drbd_rs_complete_io(mdev, e_sector);
144
145 if (do_wake)
146 wake_up(&mdev->ee_wait);
147
148 if (do_al_complete_io)
149 drbd_al_complete_io(mdev, e_sector);
150
151 wake_asender(mdev);
152 put_ldev(mdev);
153}
154
155/* writes on behalf of the partner, or resync writes,
156 * "submitted" by the receiver.
157 */
158void drbd_endio_sec(struct bio *bio, int error)
159{
160 struct drbd_epoch_entry *e = bio->bi_private;
161 struct drbd_conf *mdev = e->mdev;
162 int uptodate = bio_flagged(bio, BIO_UPTODATE);
163 int is_write = bio_data_dir(bio) == WRITE;
164
165 if (error && __ratelimit(&drbd_ratelimit_state))
166 dev_warn(DEV, "%s: error=%d s=%llus\n",
167 is_write ? "write" : "read", error,
168 (unsigned long long)e->sector);
169 if (!error && !uptodate) {
170 if (__ratelimit(&drbd_ratelimit_state))
171 dev_warn(DEV, "%s: setting error to -EIO s=%llus\n",
172 is_write ? "write" : "read",
173 (unsigned long long)e->sector);
174 /* strange behavior of some lower level drivers...
175 * fail the request by clearing the uptodate flag,
176 * but do not return any error?! */
177 error = -EIO;
178 }
179
180 if (error)
181 set_bit(__EE_WAS_ERROR, &e->flags);
182
183 bio_put(bio); /* no need for the bio anymore */
184 if (atomic_dec_and_test(&e->pending_bios)) {
185 if (is_write)
186 drbd_endio_write_sec_final(e);
187 else
188 drbd_endio_read_sec_final(e);
189 }
190}
191
192/* read, readA or write requests on R_PRIMARY coming from drbd_make_request
193 */
194void drbd_endio_pri(struct bio *bio, int error)
195{
196 unsigned long flags;
197 struct drbd_request *req = bio->bi_private;
198 struct drbd_conf *mdev = req->mdev;
199 struct bio_and_error m;
200 enum drbd_req_event what;
201 int uptodate = bio_flagged(bio, BIO_UPTODATE);
202
203 if (!error && !uptodate) {
204 dev_warn(DEV, "p %s: setting error to -EIO\n",
205 bio_data_dir(bio) == WRITE ? "write" : "read");
206 /* strange behavior of some lower level drivers...
207 * fail the request by clearing the uptodate flag,
208 * but do not return any error?! */
209 error = -EIO;
210 }
211
212 /* to avoid recursion in __req_mod */
213 if (unlikely(error)) {
214 what = (bio_data_dir(bio) == WRITE)
215 ? write_completed_with_error
216 : (bio_rw(bio) == READ)
217 ? read_completed_with_error
218 : read_ahead_completed_with_error;
219 } else
220 what = completed_ok;
221
222 bio_put(req->private_bio);
223 req->private_bio = ERR_PTR(error);
224
225 /* not req_mod(), we need irqsave here! */
226 spin_lock_irqsave(&mdev->req_lock, flags);
227 __req_mod(req, what, &m);
228 spin_unlock_irqrestore(&mdev->req_lock, flags);
229
230 if (m.bio)
231 complete_master_bio(mdev, &m);
232}
233
234int w_read_retry_remote(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
235{
236 struct drbd_request *req = container_of(w, struct drbd_request, w);
237
238 /* We should not detach for read io-error,
239 * but try to WRITE the P_DATA_REPLY to the failed location,
240 * to give the disk the chance to relocate that block */
241
242 spin_lock_irq(&mdev->req_lock);
243 if (cancel || mdev->state.pdsk != D_UP_TO_DATE) {
244 _req_mod(req, read_retry_remote_canceled);
245 spin_unlock_irq(&mdev->req_lock);
246 return 1;
247 }
248 spin_unlock_irq(&mdev->req_lock);
249
250 return w_send_read_req(mdev, w, 0);
251}
252
253void drbd_csum_ee(struct drbd_conf *mdev, struct crypto_hash *tfm, struct drbd_epoch_entry *e, void *digest)
254{
255 struct hash_desc desc;
256 struct scatterlist sg;
257 struct page *page = e->pages;
258 struct page *tmp;
259 unsigned len;
260
261 desc.tfm = tfm;
262 desc.flags = 0;
263
264 sg_init_table(&sg, 1);
265 crypto_hash_init(&desc);
266
267 while ((tmp = page_chain_next(page))) {
268 /* all but the last page will be fully used */
269 sg_set_page(&sg, page, PAGE_SIZE, 0);
270 crypto_hash_update(&desc, &sg, sg.length);
271 page = tmp;
272 }
273 /* and now the last, possibly only partially used page */
274 len = e->size & (PAGE_SIZE - 1);
275 sg_set_page(&sg, page, len ?: PAGE_SIZE, 0);
276 crypto_hash_update(&desc, &sg, sg.length);
277 crypto_hash_final(&desc, digest);
278}
279
280void drbd_csum_bio(struct drbd_conf *mdev, struct crypto_hash *tfm, struct bio *bio, void *digest)
281{
282 struct hash_desc desc;
283 struct scatterlist sg;
284 struct bio_vec *bvec;
285 int i;
286
287 desc.tfm = tfm;
288 desc.flags = 0;
289
290 sg_init_table(&sg, 1);
291 crypto_hash_init(&desc);
292
293 __bio_for_each_segment(bvec, bio, i, 0) {
294 sg_set_page(&sg, bvec->bv_page, bvec->bv_len, bvec->bv_offset);
295 crypto_hash_update(&desc, &sg, sg.length);
296 }
297 crypto_hash_final(&desc, digest);
298}
299
300/* TODO merge common code with w_e_end_ov_req */
301int w_e_send_csum(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
302{
303 struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
304 int digest_size;
305 void *digest;
306 int ok = 1;
307
308 D_ASSERT(e->block_id == DRBD_MAGIC + 0xbeef);
309
310 if (unlikely(cancel))
311 goto out;
312
313 if (likely((e->flags & EE_WAS_ERROR) != 0))
314 goto out;
315
316 digest_size = crypto_hash_digestsize(mdev->csums_tfm);
317 digest = kmalloc(digest_size, GFP_NOIO);
318 if (digest) {
319 sector_t sector = e->sector;
320 unsigned int size = e->size;
321 drbd_csum_ee(mdev, mdev->csums_tfm, e, digest);
322 /* Free e and pages before send.
323 * In case we block on congestion, we could otherwise run into
324 * some distributed deadlock, if the other side blocks on
325 * congestion as well, because our receiver blocks in
326 * drbd_pp_alloc due to pp_in_use > max_buffers. */
327 drbd_free_ee(mdev, e);
328 e = NULL;
329 inc_rs_pending(mdev);
330 ok = drbd_send_drequest_csum(mdev, sector, size,
331 digest, digest_size,
332 P_CSUM_RS_REQUEST);
333 kfree(digest);
334 } else {
335 dev_err(DEV, "kmalloc() of digest failed.\n");
336 ok = 0;
337 }
338
339out:
340 if (e)
341 drbd_free_ee(mdev, e);
342
343 if (unlikely(!ok))
344 dev_err(DEV, "drbd_send_drequest(..., csum) failed\n");
345 return ok;
346}
347
348#define GFP_TRY (__GFP_HIGHMEM | __GFP_NOWARN)
349
350static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size)
351{
352 struct drbd_epoch_entry *e;
353
354 if (!get_ldev(mdev))
355 return -EIO;
356
357 if (drbd_rs_should_slow_down(mdev, sector))
358 goto defer;
359
360 /* GFP_TRY, because if there is no memory available right now, this may
361 * be rescheduled for later. It is "only" background resync, after all. */
362 e = drbd_alloc_ee(mdev, DRBD_MAGIC+0xbeef, sector, size, GFP_TRY);
363 if (!e)
364 goto defer;
365
366 e->w.cb = w_e_send_csum;
367 spin_lock_irq(&mdev->req_lock);
368 list_add(&e->w.list, &mdev->read_ee);
369 spin_unlock_irq(&mdev->req_lock);
370
371 atomic_add(size >> 9, &mdev->rs_sect_ev);
372 if (drbd_submit_ee(mdev, e, READ, DRBD_FAULT_RS_RD) == 0)
373 return 0;
374
375 /* If it failed because of ENOMEM, retry should help. If it failed
376 * because bio_add_page failed (probably broken lower level driver),
377 * retry may or may not help.
378 * If it does not, you may need to force disconnect. */
379 spin_lock_irq(&mdev->req_lock);
380 list_del(&e->w.list);
381 spin_unlock_irq(&mdev->req_lock);
382
383 drbd_free_ee(mdev, e);
384defer:
385 put_ldev(mdev);
386 return -EAGAIN;
387}
388
389int w_resync_timer(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
390{
391 switch (mdev->state.conn) {
392 case C_VERIFY_S:
393 w_make_ov_request(mdev, w, cancel);
394 break;
395 case C_SYNC_TARGET:
396 w_make_resync_request(mdev, w, cancel);
397 break;
398 }
399
400 return 1;
401}
402
403void resync_timer_fn(unsigned long data)
404{
405 struct drbd_conf *mdev = (struct drbd_conf *) data;
406
407 if (list_empty(&mdev->resync_work.list))
408 drbd_queue_work(&mdev->data.work, &mdev->resync_work);
409}
410
411static void fifo_set(struct fifo_buffer *fb, int value)
412{
413 int i;
414
415 for (i = 0; i < fb->size; i++)
416 fb->values[i] = value;
417}
418
419static int fifo_push(struct fifo_buffer *fb, int value)
420{
421 int ov;
422
423 ov = fb->values[fb->head_index];
424 fb->values[fb->head_index++] = value;
425
426 if (fb->head_index >= fb->size)
427 fb->head_index = 0;
428
429 return ov;
430}
431
432static void fifo_add_val(struct fifo_buffer *fb, int value)
433{
434 int i;
435
436 for (i = 0; i < fb->size; i++)
437 fb->values[i] += value;
438}
439
440static int drbd_rs_controller(struct drbd_conf *mdev)
441{
442 unsigned int sect_in; /* Number of sectors that came in since the last turn */
443 unsigned int want; /* The number of sectors we want in the proxy */
444 int req_sect; /* Number of sectors to request in this turn */
445 int correction; /* Number of sectors more we need in the proxy*/
446 int cps; /* correction per invocation of drbd_rs_controller() */
447 int steps; /* Number of time steps to plan ahead */
448 int curr_corr;
449 int max_sect;
450
451 sect_in = atomic_xchg(&mdev->rs_sect_in, 0); /* Number of sectors that came in */
452 mdev->rs_in_flight -= sect_in;
453
454 spin_lock(&mdev->peer_seq_lock); /* get an atomic view on mdev->rs_plan_s */
455
456 steps = mdev->rs_plan_s.size; /* (mdev->sync_conf.c_plan_ahead * 10 * SLEEP_TIME) / HZ; */
457
458 if (mdev->rs_in_flight + sect_in == 0) { /* At start of resync */
459 want = ((mdev->sync_conf.rate * 2 * SLEEP_TIME) / HZ) * steps;
460 } else { /* normal path */
461 want = mdev->sync_conf.c_fill_target ? mdev->sync_conf.c_fill_target :
462 sect_in * mdev->sync_conf.c_delay_target * HZ / (SLEEP_TIME * 10);
463 }
464
465 correction = want - mdev->rs_in_flight - mdev->rs_planed;
466
467 /* Plan ahead */
468 cps = correction / steps;
469 fifo_add_val(&mdev->rs_plan_s, cps);
470 mdev->rs_planed += cps * steps;
471
472 /* What we do in this step */
473 curr_corr = fifo_push(&mdev->rs_plan_s, 0);
474 spin_unlock(&mdev->peer_seq_lock);
475 mdev->rs_planed -= curr_corr;
476
477 req_sect = sect_in + curr_corr;
478 if (req_sect < 0)
479 req_sect = 0;
480
481 max_sect = (mdev->sync_conf.c_max_rate * 2 * SLEEP_TIME) / HZ;
482 if (req_sect > max_sect)
483 req_sect = max_sect;
484
485 /*
486 dev_warn(DEV, "si=%u if=%d wa=%u co=%d st=%d cps=%d pl=%d cc=%d rs=%d\n",
487 sect_in, mdev->rs_in_flight, want, correction,
488 steps, cps, mdev->rs_planed, curr_corr, req_sect);
489 */
490
491 return req_sect;
492}
493
494static int drbd_rs_number_requests(struct drbd_conf *mdev)
495{
496 int number;
497 if (mdev->rs_plan_s.size) { /* mdev->sync_conf.c_plan_ahead */
498 number = drbd_rs_controller(mdev) >> (BM_BLOCK_SHIFT - 9);
499 mdev->c_sync_rate = number * HZ * (BM_BLOCK_SIZE / 1024) / SLEEP_TIME;
500 } else {
501 mdev->c_sync_rate = mdev->sync_conf.rate;
502 number = SLEEP_TIME * mdev->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ);
503 }
504
505 /* ignore the amount of pending requests, the resync controller should
506 * throttle down to incoming reply rate soon enough anyways. */
507 return number;
508}
509
510static int w_make_resync_request(struct drbd_conf *mdev,
511 struct drbd_work *w, int cancel)
512{
513 unsigned long bit;
514 sector_t sector;
515 const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
516 int max_bio_size;
517 int number, rollback_i, size;
518 int align, queued, sndbuf;
519 int i = 0;
520
521 if (unlikely(cancel))
522 return 1;
523
524 if (mdev->rs_total == 0) {
525 /* empty resync? */
526 drbd_resync_finished(mdev);
527 return 1;
528 }
529
530 if (!get_ldev(mdev)) {
531 /* Since we only need to access mdev->rsync a
532 get_ldev_if_state(mdev,D_FAILED) would be sufficient, but
533 to continue resync with a broken disk makes no sense at
534 all */
535 dev_err(DEV, "Disk broke down during resync!\n");
536 return 1;
537 }
538
539 max_bio_size = queue_max_hw_sectors(mdev->rq_queue) << 9;
540 number = drbd_rs_number_requests(mdev);
541 if (number == 0)
542 goto requeue;
543
544 for (i = 0; i < number; i++) {
545 /* Stop generating RS requests, when half of the send buffer is filled */
546 mutex_lock(&mdev->data.mutex);
547 if (mdev->data.socket) {
548 queued = mdev->data.socket->sk->sk_wmem_queued;
549 sndbuf = mdev->data.socket->sk->sk_sndbuf;
550 } else {
551 queued = 1;
552 sndbuf = 0;
553 }
554 mutex_unlock(&mdev->data.mutex);
555 if (queued > sndbuf / 2)
556 goto requeue;
557
558next_sector:
559 size = BM_BLOCK_SIZE;
560 bit = drbd_bm_find_next(mdev, mdev->bm_resync_fo);
561
562 if (bit == DRBD_END_OF_BITMAP) {
563 mdev->bm_resync_fo = drbd_bm_bits(mdev);
564 put_ldev(mdev);
565 return 1;
566 }
567
568 sector = BM_BIT_TO_SECT(bit);
569
570 if (drbd_rs_should_slow_down(mdev, sector) ||
571 drbd_try_rs_begin_io(mdev, sector)) {
572 mdev->bm_resync_fo = bit;
573 goto requeue;
574 }
575 mdev->bm_resync_fo = bit + 1;
576
577 if (unlikely(drbd_bm_test_bit(mdev, bit) == 0)) {
578 drbd_rs_complete_io(mdev, sector);
579 goto next_sector;
580 }
581
582#if DRBD_MAX_BIO_SIZE > BM_BLOCK_SIZE
583 /* try to find some adjacent bits.
584 * we stop if we have already the maximum req size.
585 *
586 * Additionally always align bigger requests, in order to
587 * be prepared for all stripe sizes of software RAIDs.
588 */
589 align = 1;
590 rollback_i = i;
591 for (;;) {
592 if (size + BM_BLOCK_SIZE > max_bio_size)
593 break;
594
595 /* Be always aligned */
596 if (sector & ((1<<(align+3))-1))
597 break;
598
599 /* do not cross extent boundaries */
600 if (((bit+1) & BM_BLOCKS_PER_BM_EXT_MASK) == 0)
601 break;
602 /* now, is it actually dirty, after all?
603 * caution, drbd_bm_test_bit is tri-state for some
604 * obscure reason; ( b == 0 ) would get the out-of-band
605 * only accidentally right because of the "oddly sized"
606 * adjustment below */
607 if (drbd_bm_test_bit(mdev, bit+1) != 1)
608 break;
609 bit++;
610 size += BM_BLOCK_SIZE;
611 if ((BM_BLOCK_SIZE << align) <= size)
612 align++;
613 i++;
614 }
615 /* if we merged some,
616 * reset the offset to start the next drbd_bm_find_next from */
617 if (size > BM_BLOCK_SIZE)
618 mdev->bm_resync_fo = bit + 1;
619#endif
620
621 /* adjust very last sectors, in case we are oddly sized */
622 if (sector + (size>>9) > capacity)
623 size = (capacity-sector)<<9;
624 if (mdev->agreed_pro_version >= 89 && mdev->csums_tfm) {
625 switch (read_for_csum(mdev, sector, size)) {
626 case -EIO: /* Disk failure */
627 put_ldev(mdev);
628 return 0;
629 case -EAGAIN: /* allocation failed, or ldev busy */
630 drbd_rs_complete_io(mdev, sector);
631 mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
632 i = rollback_i;
633 goto requeue;
634 case 0:
635 /* everything ok */
636 break;
637 default:
638 BUG();
639 }
640 } else {
641 inc_rs_pending(mdev);
642 if (!drbd_send_drequest(mdev, P_RS_DATA_REQUEST,
643 sector, size, ID_SYNCER)) {
644 dev_err(DEV, "drbd_send_drequest() failed, aborting...\n");
645 dec_rs_pending(mdev);
646 put_ldev(mdev);
647 return 0;
648 }
649 }
650 }
651
652 if (mdev->bm_resync_fo >= drbd_bm_bits(mdev)) {
653 /* last syncer _request_ was sent,
654 * but the P_RS_DATA_REPLY not yet received. sync will end (and
655 * next sync group will resume), as soon as we receive the last
656 * resync data block, and the last bit is cleared.
657 * until then resync "work" is "inactive" ...
658 */
659 put_ldev(mdev);
660 return 1;
661 }
662
663 requeue:
664 mdev->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9));
665 mod_timer(&mdev->resync_timer, jiffies + SLEEP_TIME);
666 put_ldev(mdev);
667 return 1;
668}
669
670static int w_make_ov_request(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
671{
672 int number, i, size;
673 sector_t sector;
674 const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
675
676 if (unlikely(cancel))
677 return 1;
678
679 number = drbd_rs_number_requests(mdev);
680
681 sector = mdev->ov_position;
682 for (i = 0; i < number; i++) {
683 if (sector >= capacity) {
684 return 1;
685 }
686
687 size = BM_BLOCK_SIZE;
688
689 if (drbd_rs_should_slow_down(mdev, sector) ||
690 drbd_try_rs_begin_io(mdev, sector)) {
691 mdev->ov_position = sector;
692 goto requeue;
693 }
694
695 if (sector + (size>>9) > capacity)
696 size = (capacity-sector)<<9;
697
698 inc_rs_pending(mdev);
699 if (!drbd_send_ov_request(mdev, sector, size)) {
700 dec_rs_pending(mdev);
701 return 0;
702 }
703 sector += BM_SECT_PER_BIT;
704 }
705 mdev->ov_position = sector;
706
707 requeue:
708 mdev->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9));
709 mod_timer(&mdev->resync_timer, jiffies + SLEEP_TIME);
710 return 1;
711}
712
713
714void start_resync_timer_fn(unsigned long data)
715{
716 struct drbd_conf *mdev = (struct drbd_conf *) data;
717
718 drbd_queue_work(&mdev->data.work, &mdev->start_resync_work);
719}
720
721int w_start_resync(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
722{
723 if (atomic_read(&mdev->unacked_cnt) || atomic_read(&mdev->rs_pending_cnt)) {
724 dev_warn(DEV, "w_start_resync later...\n");
725 mdev->start_resync_timer.expires = jiffies + HZ/10;
726 add_timer(&mdev->start_resync_timer);
727 return 1;
728 }
729
730 drbd_start_resync(mdev, C_SYNC_SOURCE);
731 clear_bit(AHEAD_TO_SYNC_SOURCE, &mdev->current_epoch->flags);
732 return 1;
733}
734
735int w_ov_finished(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
736{
737 kfree(w);
738 ov_oos_print(mdev);
739 drbd_resync_finished(mdev);
740
741 return 1;
742}
743
744static int w_resync_finished(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
745{
746 kfree(w);
747
748 drbd_resync_finished(mdev);
749
750 return 1;
751}
752
753static void ping_peer(struct drbd_conf *mdev)
754{
755 clear_bit(GOT_PING_ACK, &mdev->flags);
756 request_ping(mdev);
757 wait_event(mdev->misc_wait,
758 test_bit(GOT_PING_ACK, &mdev->flags) || mdev->state.conn < C_CONNECTED);
759}
760
761int drbd_resync_finished(struct drbd_conf *mdev)
762{
763 unsigned long db, dt, dbdt;
764 unsigned long n_oos;
765 union drbd_state os, ns;
766 struct drbd_work *w;
767 char *khelper_cmd = NULL;
768 int verify_done = 0;
769
770 /* Remove all elements from the resync LRU. Since future actions
771 * might set bits in the (main) bitmap, then the entries in the
772 * resync LRU would be wrong. */
773 if (drbd_rs_del_all(mdev)) {
774 /* In case this is not possible now, most probably because
775 * there are P_RS_DATA_REPLY Packets lingering on the worker's
776 * queue (or even the read operations for those packets
777 * is not finished by now). Retry in 100ms. */
778
779 schedule_timeout_interruptible(HZ / 10);
780 w = kmalloc(sizeof(struct drbd_work), GFP_ATOMIC);
781 if (w) {
782 w->cb = w_resync_finished;
783 drbd_queue_work(&mdev->data.work, w);
784 return 1;
785 }
786 dev_err(DEV, "Warn failed to drbd_rs_del_all() and to kmalloc(w).\n");
787 }
788
789 dt = (jiffies - mdev->rs_start - mdev->rs_paused) / HZ;
790 if (dt <= 0)
791 dt = 1;
792 db = mdev->rs_total;
793 dbdt = Bit2KB(db/dt);
794 mdev->rs_paused /= HZ;
795
796 if (!get_ldev(mdev))
797 goto out;
798
799 ping_peer(mdev);
800
801 spin_lock_irq(&mdev->req_lock);
802 os = mdev->state;
803
804 verify_done = (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T);
805
806 /* This protects us against multiple calls (that can happen in the presence
807 of application IO), and against connectivity loss just before we arrive here. */
808 if (os.conn <= C_CONNECTED)
809 goto out_unlock;
810
811 ns = os;
812 ns.conn = C_CONNECTED;
813
814 dev_info(DEV, "%s done (total %lu sec; paused %lu sec; %lu K/sec)\n",
815 verify_done ? "Online verify " : "Resync",
816 dt + mdev->rs_paused, mdev->rs_paused, dbdt);
817
818 n_oos = drbd_bm_total_weight(mdev);
819
820 if (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) {
821 if (n_oos) {
822 dev_alert(DEV, "Online verify found %lu %dk block out of sync!\n",
823 n_oos, Bit2KB(1));
824 khelper_cmd = "out-of-sync";
825 }
826 } else {
827 D_ASSERT((n_oos - mdev->rs_failed) == 0);
828
829 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T)
830 khelper_cmd = "after-resync-target";
831
832 if (mdev->csums_tfm && mdev->rs_total) {
833 const unsigned long s = mdev->rs_same_csum;
834 const unsigned long t = mdev->rs_total;
835 const int ratio =
836 (t == 0) ? 0 :
837 (t < 100000) ? ((s*100)/t) : (s/(t/100));
838 dev_info(DEV, "%u %% had equal checksums, eliminated: %luK; "
839 "transferred %luK total %luK\n",
840 ratio,
841 Bit2KB(mdev->rs_same_csum),
842 Bit2KB(mdev->rs_total - mdev->rs_same_csum),
843 Bit2KB(mdev->rs_total));
844 }
845 }
846
847 if (mdev->rs_failed) {
848 dev_info(DEV, " %lu failed blocks\n", mdev->rs_failed);
849
850 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) {
851 ns.disk = D_INCONSISTENT;
852 ns.pdsk = D_UP_TO_DATE;
853 } else {
854 ns.disk = D_UP_TO_DATE;
855 ns.pdsk = D_INCONSISTENT;
856 }
857 } else {
858 ns.disk = D_UP_TO_DATE;
859 ns.pdsk = D_UP_TO_DATE;
860
861 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) {
862 if (mdev->p_uuid) {
863 int i;
864 for (i = UI_BITMAP ; i <= UI_HISTORY_END ; i++)
865 _drbd_uuid_set(mdev, i, mdev->p_uuid[i]);
866 drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_CURRENT]);
867 _drbd_uuid_set(mdev, UI_CURRENT, mdev->p_uuid[UI_CURRENT]);
868 } else {
869 dev_err(DEV, "mdev->p_uuid is NULL! BUG\n");
870 }
871 }
872
873 if (!(os.conn == C_VERIFY_S || os.conn == C_VERIFY_T)) {
874 /* for verify runs, we don't update uuids here,
875 * so there would be nothing to report. */
876 drbd_uuid_set_bm(mdev, 0UL);
877 drbd_print_uuids(mdev, "updated UUIDs");
878 if (mdev->p_uuid) {
879 /* Now the two UUID sets are equal, update what we
880 * know of the peer. */
881 int i;
882 for (i = UI_CURRENT ; i <= UI_HISTORY_END ; i++)
883 mdev->p_uuid[i] = mdev->ldev->md.uuid[i];
884 }
885 }
886 }
887
888 _drbd_set_state(mdev, ns, CS_VERBOSE, NULL);
889out_unlock:
890 spin_unlock_irq(&mdev->req_lock);
891 put_ldev(mdev);
892out:
893 mdev->rs_total = 0;
894 mdev->rs_failed = 0;
895 mdev->rs_paused = 0;
896 if (verify_done)
897 mdev->ov_start_sector = 0;
898
899 drbd_md_sync(mdev);
900
901 if (khelper_cmd)
902 drbd_khelper(mdev, khelper_cmd);
903
904 return 1;
905}
906
907/* helper */
908static void move_to_net_ee_or_free(struct drbd_conf *mdev, struct drbd_epoch_entry *e)
909{
910 if (drbd_ee_has_active_page(e)) {
911 /* This might happen if sendpage() has not finished */
912 int i = (e->size + PAGE_SIZE -1) >> PAGE_SHIFT;
913 atomic_add(i, &mdev->pp_in_use_by_net);
914 atomic_sub(i, &mdev->pp_in_use);
915 spin_lock_irq(&mdev->req_lock);
916 list_add_tail(&e->w.list, &mdev->net_ee);
917 spin_unlock_irq(&mdev->req_lock);
918 wake_up(&drbd_pp_wait);
919 } else
920 drbd_free_ee(mdev, e);
921}
922
923/**
924 * w_e_end_data_req() - Worker callback, to send a P_DATA_REPLY packet in response to a P_DATA_REQUEST
925 * @mdev: DRBD device.
926 * @w: work object.
927 * @cancel: The connection will be closed anyways
928 */
929int w_e_end_data_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
930{
931 struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
932 int ok;
933
934 if (unlikely(cancel)) {
935 drbd_free_ee(mdev, e);
936 dec_unacked(mdev);
937 return 1;
938 }
939
940 if (likely((e->flags & EE_WAS_ERROR) == 0)) {
941 ok = drbd_send_block(mdev, P_DATA_REPLY, e);
942 } else {
943 if (__ratelimit(&drbd_ratelimit_state))
944 dev_err(DEV, "Sending NegDReply. sector=%llus.\n",
945 (unsigned long long)e->sector);
946
947 ok = drbd_send_ack(mdev, P_NEG_DREPLY, e);
948 }
949
950 dec_unacked(mdev);
951
952 move_to_net_ee_or_free(mdev, e);
953
954 if (unlikely(!ok))
955 dev_err(DEV, "drbd_send_block() failed\n");
956 return ok;
957}
958
959/**
960 * w_e_end_rsdata_req() - Worker callback to send a P_RS_DATA_REPLY packet in response to a P_RS_DATA_REQUESTRS
961 * @mdev: DRBD device.
962 * @w: work object.
963 * @cancel: The connection will be closed anyways
964 */
965int w_e_end_rsdata_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
966{
967 struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
968 int ok;
969
970 if (unlikely(cancel)) {
971 drbd_free_ee(mdev, e);
972 dec_unacked(mdev);
973 return 1;
974 }
975
976 if (get_ldev_if_state(mdev, D_FAILED)) {
977 drbd_rs_complete_io(mdev, e->sector);
978 put_ldev(mdev);
979 }
980
981 if (mdev->state.conn == C_AHEAD) {
982 ok = drbd_send_ack(mdev, P_RS_CANCEL, e);
983 } else if (likely((e->flags & EE_WAS_ERROR) == 0)) {
984 if (likely(mdev->state.pdsk >= D_INCONSISTENT)) {
985 inc_rs_pending(mdev);
986 ok = drbd_send_block(mdev, P_RS_DATA_REPLY, e);
987 } else {
988 if (__ratelimit(&drbd_ratelimit_state))
989 dev_err(DEV, "Not sending RSDataReply, "
990 "partner DISKLESS!\n");
991 ok = 1;
992 }
993 } else {
994 if (__ratelimit(&drbd_ratelimit_state))
995 dev_err(DEV, "Sending NegRSDReply. sector %llus.\n",
996 (unsigned long long)e->sector);
997
998 ok = drbd_send_ack(mdev, P_NEG_RS_DREPLY, e);
999
1000 /* update resync data with failure */
1001 drbd_rs_failed_io(mdev, e->sector, e->size);
1002 }
1003
1004 dec_unacked(mdev);
1005
1006 move_to_net_ee_or_free(mdev, e);
1007
1008 if (unlikely(!ok))
1009 dev_err(DEV, "drbd_send_block() failed\n");
1010 return ok;
1011}
1012
1013int w_e_end_csum_rs_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1014{
1015 struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
1016 struct digest_info *di;
1017 int digest_size;
1018 void *digest = NULL;
1019 int ok, eq = 0;
1020
1021 if (unlikely(cancel)) {
1022 drbd_free_ee(mdev, e);
1023 dec_unacked(mdev);
1024 return 1;
1025 }
1026
1027 if (get_ldev(mdev)) {
1028 drbd_rs_complete_io(mdev, e->sector);
1029 put_ldev(mdev);
1030 }
1031
1032 di = e->digest;
1033
1034 if (likely((e->flags & EE_WAS_ERROR) == 0)) {
1035 /* quick hack to try to avoid a race against reconfiguration.
1036 * a real fix would be much more involved,
1037 * introducing more locking mechanisms */
1038 if (mdev->csums_tfm) {
1039 digest_size = crypto_hash_digestsize(mdev->csums_tfm);
1040 D_ASSERT(digest_size == di->digest_size);
1041 digest = kmalloc(digest_size, GFP_NOIO);
1042 }
1043 if (digest) {
1044 drbd_csum_ee(mdev, mdev->csums_tfm, e, digest);
1045 eq = !memcmp(digest, di->digest, digest_size);
1046 kfree(digest);
1047 }
1048
1049 if (eq) {
1050 drbd_set_in_sync(mdev, e->sector, e->size);
1051 /* rs_same_csums unit is BM_BLOCK_SIZE */
1052 mdev->rs_same_csum += e->size >> BM_BLOCK_SHIFT;
1053 ok = drbd_send_ack(mdev, P_RS_IS_IN_SYNC, e);
1054 } else {
1055 inc_rs_pending(mdev);
1056 e->block_id = ID_SYNCER; /* By setting block_id, digest pointer becomes invalid! */
1057 e->flags &= ~EE_HAS_DIGEST; /* This e no longer has a digest pointer */
1058 kfree(di);
1059 ok = drbd_send_block(mdev, P_RS_DATA_REPLY, e);
1060 }
1061 } else {
1062 ok = drbd_send_ack(mdev, P_NEG_RS_DREPLY, e);
1063 if (__ratelimit(&drbd_ratelimit_state))
1064 dev_err(DEV, "Sending NegDReply. I guess it gets messy.\n");
1065 }
1066
1067 dec_unacked(mdev);
1068 move_to_net_ee_or_free(mdev, e);
1069
1070 if (unlikely(!ok))
1071 dev_err(DEV, "drbd_send_block/ack() failed\n");
1072 return ok;
1073}
1074
1075/* TODO merge common code with w_e_send_csum */
1076int w_e_end_ov_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1077{
1078 struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
1079 sector_t sector = e->sector;
1080 unsigned int size = e->size;
1081 int digest_size;
1082 void *digest;
1083 int ok = 1;
1084
1085 if (unlikely(cancel))
1086 goto out;
1087
1088 digest_size = crypto_hash_digestsize(mdev->verify_tfm);
1089 digest = kmalloc(digest_size, GFP_NOIO);
1090 if (!digest) {
1091 ok = 0; /* terminate the connection in case the allocation failed */
1092 goto out;
1093 }
1094
1095 if (likely(!(e->flags & EE_WAS_ERROR)))
1096 drbd_csum_ee(mdev, mdev->verify_tfm, e, digest);
1097 else
1098 memset(digest, 0, digest_size);
1099
1100 /* Free e and pages before send.
1101 * In case we block on congestion, we could otherwise run into
1102 * some distributed deadlock, if the other side blocks on
1103 * congestion as well, because our receiver blocks in
1104 * drbd_pp_alloc due to pp_in_use > max_buffers. */
1105 drbd_free_ee(mdev, e);
1106 e = NULL;
1107 inc_rs_pending(mdev);
1108 ok = drbd_send_drequest_csum(mdev, sector, size,
1109 digest, digest_size,
1110 P_OV_REPLY);
1111 if (!ok)
1112 dec_rs_pending(mdev);
1113 kfree(digest);
1114
1115out:
1116 if (e)
1117 drbd_free_ee(mdev, e);
1118 dec_unacked(mdev);
1119 return ok;
1120}
1121
1122void drbd_ov_oos_found(struct drbd_conf *mdev, sector_t sector, int size)
1123{
1124 if (mdev->ov_last_oos_start + mdev->ov_last_oos_size == sector) {
1125 mdev->ov_last_oos_size += size>>9;
1126 } else {
1127 mdev->ov_last_oos_start = sector;
1128 mdev->ov_last_oos_size = size>>9;
1129 }
1130 drbd_set_out_of_sync(mdev, sector, size);
1131}
1132
1133int w_e_end_ov_reply(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1134{
1135 struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
1136 struct digest_info *di;
1137 void *digest;
1138 sector_t sector = e->sector;
1139 unsigned int size = e->size;
1140 int digest_size;
1141 int ok, eq = 0;
1142
1143 if (unlikely(cancel)) {
1144 drbd_free_ee(mdev, e);
1145 dec_unacked(mdev);
1146 return 1;
1147 }
1148
1149 /* after "cancel", because after drbd_disconnect/drbd_rs_cancel_all
1150 * the resync lru has been cleaned up already */
1151 if (get_ldev(mdev)) {
1152 drbd_rs_complete_io(mdev, e->sector);
1153 put_ldev(mdev);
1154 }
1155
1156 di = e->digest;
1157
1158 if (likely((e->flags & EE_WAS_ERROR) == 0)) {
1159 digest_size = crypto_hash_digestsize(mdev->verify_tfm);
1160 digest = kmalloc(digest_size, GFP_NOIO);
1161 if (digest) {
1162 drbd_csum_ee(mdev, mdev->verify_tfm, e, digest);
1163
1164 D_ASSERT(digest_size == di->digest_size);
1165 eq = !memcmp(digest, di->digest, digest_size);
1166 kfree(digest);
1167 }
1168 }
1169
1170 /* Free e and pages before send.
1171 * In case we block on congestion, we could otherwise run into
1172 * some distributed deadlock, if the other side blocks on
1173 * congestion as well, because our receiver blocks in
1174 * drbd_pp_alloc due to pp_in_use > max_buffers. */
1175 drbd_free_ee(mdev, e);
1176 if (!eq)
1177 drbd_ov_oos_found(mdev, sector, size);
1178 else
1179 ov_oos_print(mdev);
1180
1181 ok = drbd_send_ack_ex(mdev, P_OV_RESULT, sector, size,
1182 eq ? ID_IN_SYNC : ID_OUT_OF_SYNC);
1183
1184 dec_unacked(mdev);
1185
1186 --mdev->ov_left;
1187
1188 /* let's advance progress step marks only for every other megabyte */
1189 if ((mdev->ov_left & 0x200) == 0x200)
1190 drbd_advance_rs_marks(mdev, mdev->ov_left);
1191
1192 if (mdev->ov_left == 0) {
1193 ov_oos_print(mdev);
1194 drbd_resync_finished(mdev);
1195 }
1196
1197 return ok;
1198}
1199
1200int w_prev_work_done(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1201{
1202 struct drbd_wq_barrier *b = container_of(w, struct drbd_wq_barrier, w);
1203 complete(&b->done);
1204 return 1;
1205}
1206
1207int w_send_barrier(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1208{
1209 struct drbd_tl_epoch *b = container_of(w, struct drbd_tl_epoch, w);
1210 struct p_barrier *p = &mdev->data.sbuf.barrier;
1211 int ok = 1;
1212
1213 /* really avoid racing with tl_clear. w.cb may have been referenced
1214 * just before it was reassigned and re-queued, so double check that.
1215 * actually, this race was harmless, since we only try to send the
1216 * barrier packet here, and otherwise do nothing with the object.
1217 * but compare with the head of w_clear_epoch */
1218 spin_lock_irq(&mdev->req_lock);
1219 if (w->cb != w_send_barrier || mdev->state.conn < C_CONNECTED)
1220 cancel = 1;
1221 spin_unlock_irq(&mdev->req_lock);
1222 if (cancel)
1223 return 1;
1224
1225 if (!drbd_get_data_sock(mdev))
1226 return 0;
1227 p->barrier = b->br_number;
1228 /* inc_ap_pending was done where this was queued.
1229 * dec_ap_pending will be done in got_BarrierAck
1230 * or (on connection loss) in w_clear_epoch. */
1231 ok = _drbd_send_cmd(mdev, mdev->data.socket, P_BARRIER,
1232 (struct p_header80 *)p, sizeof(*p), 0);
1233 drbd_put_data_sock(mdev);
1234
1235 return ok;
1236}
1237
1238int w_send_write_hint(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1239{
1240 if (cancel)
1241 return 1;
1242 return drbd_send_short_cmd(mdev, P_UNPLUG_REMOTE);
1243}
1244
1245int w_send_oos(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1246{
1247 struct drbd_request *req = container_of(w, struct drbd_request, w);
1248 int ok;
1249
1250 if (unlikely(cancel)) {
1251 req_mod(req, send_canceled);
1252 return 1;
1253 }
1254
1255 ok = drbd_send_oos(mdev, req);
1256 req_mod(req, oos_handed_to_network);
1257
1258 return ok;
1259}
1260
1261/**
1262 * w_send_dblock() - Worker callback to send a P_DATA packet in order to mirror a write request
1263 * @mdev: DRBD device.
1264 * @w: work object.
1265 * @cancel: The connection will be closed anyways
1266 */
1267int w_send_dblock(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1268{
1269 struct drbd_request *req = container_of(w, struct drbd_request, w);
1270 int ok;
1271
1272 if (unlikely(cancel)) {
1273 req_mod(req, send_canceled);
1274 return 1;
1275 }
1276
1277 ok = drbd_send_dblock(mdev, req);
1278 req_mod(req, ok ? handed_over_to_network : send_failed);
1279
1280 return ok;
1281}
1282
1283/**
1284 * w_send_read_req() - Worker callback to send a read request (P_DATA_REQUEST) packet
1285 * @mdev: DRBD device.
1286 * @w: work object.
1287 * @cancel: The connection will be closed anyways
1288 */
1289int w_send_read_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1290{
1291 struct drbd_request *req = container_of(w, struct drbd_request, w);
1292 int ok;
1293
1294 if (unlikely(cancel)) {
1295 req_mod(req, send_canceled);
1296 return 1;
1297 }
1298
1299 ok = drbd_send_drequest(mdev, P_DATA_REQUEST, req->sector, req->size,
1300 (unsigned long)req);
1301
1302 if (!ok) {
1303 /* ?? we set C_TIMEOUT or C_BROKEN_PIPE in drbd_send();
1304 * so this is probably redundant */
1305 if (mdev->state.conn >= C_CONNECTED)
1306 drbd_force_state(mdev, NS(conn, C_NETWORK_FAILURE));
1307 }
1308 req_mod(req, ok ? handed_over_to_network : send_failed);
1309
1310 return ok;
1311}
1312
1313int w_restart_disk_io(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
1314{
1315 struct drbd_request *req = container_of(w, struct drbd_request, w);
1316
1317 if (bio_data_dir(req->master_bio) == WRITE && req->rq_state & RQ_IN_ACT_LOG)
1318 drbd_al_begin_io(mdev, req->sector);
1319 /* Calling drbd_al_begin_io() out of the worker might deadlocks
1320 theoretically. Practically it can not deadlock, since this is
1321 only used when unfreezing IOs. All the extents of the requests
1322 that made it into the TL are already active */
1323
1324 drbd_req_make_private_bio(req, req->master_bio);
1325 req->private_bio->bi_bdev = mdev->ldev->backing_bdev;
1326 generic_make_request(req->private_bio);
1327
1328 return 1;
1329}
1330
1331static int _drbd_may_sync_now(struct drbd_conf *mdev)
1332{
1333 struct drbd_conf *odev = mdev;
1334
1335 while (1) {
1336 if (odev->sync_conf.after == -1)
1337 return 1;
1338 odev = minor_to_mdev(odev->sync_conf.after);
1339 ERR_IF(!odev) return 1;
1340 if ((odev->state.conn >= C_SYNC_SOURCE &&
1341 odev->state.conn <= C_PAUSED_SYNC_T) ||
1342 odev->state.aftr_isp || odev->state.peer_isp ||
1343 odev->state.user_isp)
1344 return 0;
1345 }
1346}
1347
1348/**
1349 * _drbd_pause_after() - Pause resync on all devices that may not resync now
1350 * @mdev: DRBD device.
1351 *
1352 * Called from process context only (admin command and after_state_ch).
1353 */
1354static int _drbd_pause_after(struct drbd_conf *mdev)
1355{
1356 struct drbd_conf *odev;
1357 int i, rv = 0;
1358
1359 for (i = 0; i < minor_count; i++) {
1360 odev = minor_to_mdev(i);
1361 if (!odev)
1362 continue;
1363 if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
1364 continue;
1365 if (!_drbd_may_sync_now(odev))
1366 rv |= (__drbd_set_state(_NS(odev, aftr_isp, 1), CS_HARD, NULL)
1367 != SS_NOTHING_TO_DO);
1368 }
1369
1370 return rv;
1371}
1372
1373/**
1374 * _drbd_resume_next() - Resume resync on all devices that may resync now
1375 * @mdev: DRBD device.
1376 *
1377 * Called from process context only (admin command and worker).
1378 */
1379static int _drbd_resume_next(struct drbd_conf *mdev)
1380{
1381 struct drbd_conf *odev;
1382 int i, rv = 0;
1383
1384 for (i = 0; i < minor_count; i++) {
1385 odev = minor_to_mdev(i);
1386 if (!odev)
1387 continue;
1388 if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
1389 continue;
1390 if (odev->state.aftr_isp) {
1391 if (_drbd_may_sync_now(odev))
1392 rv |= (__drbd_set_state(_NS(odev, aftr_isp, 0),
1393 CS_HARD, NULL)
1394 != SS_NOTHING_TO_DO) ;
1395 }
1396 }
1397 return rv;
1398}
1399
1400void resume_next_sg(struct drbd_conf *mdev)
1401{
1402 write_lock_irq(&global_state_lock);
1403 _drbd_resume_next(mdev);
1404 write_unlock_irq(&global_state_lock);
1405}
1406
1407void suspend_other_sg(struct drbd_conf *mdev)
1408{
1409 write_lock_irq(&global_state_lock);
1410 _drbd_pause_after(mdev);
1411 write_unlock_irq(&global_state_lock);
1412}
1413
1414static int sync_after_error(struct drbd_conf *mdev, int o_minor)
1415{
1416 struct drbd_conf *odev;
1417
1418 if (o_minor == -1)
1419 return NO_ERROR;
1420 if (o_minor < -1 || minor_to_mdev(o_minor) == NULL)
1421 return ERR_SYNC_AFTER;
1422
1423 /* check for loops */
1424 odev = minor_to_mdev(o_minor);
1425 while (1) {
1426 if (odev == mdev)
1427 return ERR_SYNC_AFTER_CYCLE;
1428
1429 /* dependency chain ends here, no cycles. */
1430 if (odev->sync_conf.after == -1)
1431 return NO_ERROR;
1432
1433 /* follow the dependency chain */
1434 odev = minor_to_mdev(odev->sync_conf.after);
1435 }
1436}
1437
1438int drbd_alter_sa(struct drbd_conf *mdev, int na)
1439{
1440 int changes;
1441 int retcode;
1442
1443 write_lock_irq(&global_state_lock);
1444 retcode = sync_after_error(mdev, na);
1445 if (retcode == NO_ERROR) {
1446 mdev->sync_conf.after = na;
1447 do {
1448 changes = _drbd_pause_after(mdev);
1449 changes |= _drbd_resume_next(mdev);
1450 } while (changes);
1451 }
1452 write_unlock_irq(&global_state_lock);
1453 return retcode;
1454}
1455
1456void drbd_rs_controller_reset(struct drbd_conf *mdev)
1457{
1458 atomic_set(&mdev->rs_sect_in, 0);
1459 atomic_set(&mdev->rs_sect_ev, 0);
1460 mdev->rs_in_flight = 0;
1461 mdev->rs_planed = 0;
1462 spin_lock(&mdev->peer_seq_lock);
1463 fifo_set(&mdev->rs_plan_s, 0);
1464 spin_unlock(&mdev->peer_seq_lock);
1465}
1466
1467/**
1468 * drbd_start_resync() - Start the resync process
1469 * @mdev: DRBD device.
1470 * @side: Either C_SYNC_SOURCE or C_SYNC_TARGET
1471 *
1472 * This function might bring you directly into one of the
1473 * C_PAUSED_SYNC_* states.
1474 */
1475void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
1476{
1477 union drbd_state ns;
1478 int r;
1479
1480 if (mdev->state.conn >= C_SYNC_SOURCE && mdev->state.conn < C_AHEAD) {
1481 dev_err(DEV, "Resync already running!\n");
1482 return;
1483 }
1484
1485 if (mdev->state.conn < C_AHEAD) {
1486 /* In case a previous resync run was aborted by an IO error/detach on the peer. */
1487 drbd_rs_cancel_all(mdev);
1488 /* This should be done when we abort the resync. We definitely do not
1489 want to have this for connections going back and forth between
1490 Ahead/Behind and SyncSource/SyncTarget */
1491 }
1492
1493 if (side == C_SYNC_TARGET) {
1494 /* Since application IO was locked out during C_WF_BITMAP_T and
1495 C_WF_SYNC_UUID we are still unmodified. Before going to C_SYNC_TARGET
1496 we check that we might make the data inconsistent. */
1497 r = drbd_khelper(mdev, "before-resync-target");
1498 r = (r >> 8) & 0xff;
1499 if (r > 0) {
1500 dev_info(DEV, "before-resync-target handler returned %d, "
1501 "dropping connection.\n", r);
1502 drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
1503 return;
1504 }
1505 } else /* C_SYNC_SOURCE */ {
1506 r = drbd_khelper(mdev, "before-resync-source");
1507 r = (r >> 8) & 0xff;
1508 if (r > 0) {
1509 if (r == 3) {
1510 dev_info(DEV, "before-resync-source handler returned %d, "
1511 "ignoring. Old userland tools?", r);
1512 } else {
1513 dev_info(DEV, "before-resync-source handler returned %d, "
1514 "dropping connection.\n", r);
1515 drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
1516 return;
1517 }
1518 }
1519 }
1520
1521 drbd_state_lock(mdev);
1522
1523 if (!get_ldev_if_state(mdev, D_NEGOTIATING)) {
1524 drbd_state_unlock(mdev);
1525 return;
1526 }
1527
1528 write_lock_irq(&global_state_lock);
1529 ns = mdev->state;
1530
1531 ns.aftr_isp = !_drbd_may_sync_now(mdev);
1532
1533 ns.conn = side;
1534
1535 if (side == C_SYNC_TARGET)
1536 ns.disk = D_INCONSISTENT;
1537 else /* side == C_SYNC_SOURCE */
1538 ns.pdsk = D_INCONSISTENT;
1539
1540 r = __drbd_set_state(mdev, ns, CS_VERBOSE, NULL);
1541 ns = mdev->state;
1542
1543 if (ns.conn < C_CONNECTED)
1544 r = SS_UNKNOWN_ERROR;
1545
1546 if (r == SS_SUCCESS) {
1547 unsigned long tw = drbd_bm_total_weight(mdev);
1548 unsigned long now = jiffies;
1549 int i;
1550
1551 mdev->rs_failed = 0;
1552 mdev->rs_paused = 0;
1553 mdev->rs_same_csum = 0;
1554 mdev->rs_last_events = 0;
1555 mdev->rs_last_sect_ev = 0;
1556 mdev->rs_total = tw;
1557 mdev->rs_start = now;
1558 for (i = 0; i < DRBD_SYNC_MARKS; i++) {
1559 mdev->rs_mark_left[i] = tw;
1560 mdev->rs_mark_time[i] = now;
1561 }
1562 _drbd_pause_after(mdev);
1563 }
1564 write_unlock_irq(&global_state_lock);
1565
1566 if (r == SS_SUCCESS) {
1567 dev_info(DEV, "Began resync as %s (will sync %lu KB [%lu bits set]).\n",
1568 drbd_conn_str(ns.conn),
1569 (unsigned long) mdev->rs_total << (BM_BLOCK_SHIFT-10),
1570 (unsigned long) mdev->rs_total);
1571 if (side == C_SYNC_TARGET)
1572 mdev->bm_resync_fo = 0;
1573
1574 /* Since protocol 96, we must serialize drbd_gen_and_send_sync_uuid
1575 * with w_send_oos, or the sync target will get confused as to
1576 * how much bits to resync. We cannot do that always, because for an
1577 * empty resync and protocol < 95, we need to do it here, as we call
1578 * drbd_resync_finished from here in that case.
1579 * We drbd_gen_and_send_sync_uuid here for protocol < 96,
1580 * and from after_state_ch otherwise. */
1581 if (side == C_SYNC_SOURCE && mdev->agreed_pro_version < 96)
1582 drbd_gen_and_send_sync_uuid(mdev);
1583
1584 if (mdev->agreed_pro_version < 95 && mdev->rs_total == 0) {
1585 /* This still has a race (about when exactly the peers
1586 * detect connection loss) that can lead to a full sync
1587 * on next handshake. In 8.3.9 we fixed this with explicit
1588 * resync-finished notifications, but the fix
1589 * introduces a protocol change. Sleeping for some
1590 * time longer than the ping interval + timeout on the
1591 * SyncSource, to give the SyncTarget the chance to
1592 * detect connection loss, then waiting for a ping
1593 * response (implicit in drbd_resync_finished) reduces
1594 * the race considerably, but does not solve it. */
1595 if (side == C_SYNC_SOURCE)
1596 schedule_timeout_interruptible(
1597 mdev->net_conf->ping_int * HZ +
1598 mdev->net_conf->ping_timeo*HZ/9);
1599 drbd_resync_finished(mdev);
1600 }
1601
1602 drbd_rs_controller_reset(mdev);
1603 /* ns.conn may already be != mdev->state.conn,
1604 * we may have been paused in between, or become paused until
1605 * the timer triggers.
1606 * No matter, that is handled in resync_timer_fn() */
1607 if (ns.conn == C_SYNC_TARGET)
1608 mod_timer(&mdev->resync_timer, jiffies);
1609
1610 drbd_md_sync(mdev);
1611 }
1612 put_ldev(mdev);
1613 drbd_state_unlock(mdev);
1614}
1615
1616int drbd_worker(struct drbd_thread *thi)
1617{
1618 struct drbd_conf *mdev = thi->mdev;
1619 struct drbd_work *w = NULL;
1620 LIST_HEAD(work_list);
1621 int intr = 0, i;
1622
1623 sprintf(current->comm, "drbd%d_worker", mdev_to_minor(mdev));
1624
1625 while (get_t_state(thi) == Running) {
1626 drbd_thread_current_set_cpu(mdev);
1627
1628 if (down_trylock(&mdev->data.work.s)) {
1629 mutex_lock(&mdev->data.mutex);
1630 if (mdev->data.socket && !mdev->net_conf->no_cork)
1631 drbd_tcp_uncork(mdev->data.socket);
1632 mutex_unlock(&mdev->data.mutex);
1633
1634 intr = down_interruptible(&mdev->data.work.s);
1635
1636 mutex_lock(&mdev->data.mutex);
1637 if (mdev->data.socket && !mdev->net_conf->no_cork)
1638 drbd_tcp_cork(mdev->data.socket);
1639 mutex_unlock(&mdev->data.mutex);
1640 }
1641
1642 if (intr) {
1643 D_ASSERT(intr == -EINTR);
1644 flush_signals(current);
1645 ERR_IF (get_t_state(thi) == Running)
1646 continue;
1647 break;
1648 }
1649
1650 if (get_t_state(thi) != Running)
1651 break;
1652 /* With this break, we have done a down() but not consumed
1653 the entry from the list. The cleanup code takes care of
1654 this... */
1655
1656 w = NULL;
1657 spin_lock_irq(&mdev->data.work.q_lock);
1658 ERR_IF(list_empty(&mdev->data.work.q)) {
1659 /* something terribly wrong in our logic.
1660 * we were able to down() the semaphore,
1661 * but the list is empty... doh.
1662 *
1663 * what is the best thing to do now?
1664 * try again from scratch, restarting the receiver,
1665 * asender, whatnot? could break even more ugly,
1666 * e.g. when we are primary, but no good local data.
1667 *
1668 * I'll try to get away just starting over this loop.
1669 */
1670 spin_unlock_irq(&mdev->data.work.q_lock);
1671 continue;
1672 }
1673 w = list_entry(mdev->data.work.q.next, struct drbd_work, list);
1674 list_del_init(&w->list);
1675 spin_unlock_irq(&mdev->data.work.q_lock);
1676
1677 if (!w->cb(mdev, w, mdev->state.conn < C_CONNECTED)) {
1678 /* dev_warn(DEV, "worker: a callback failed! \n"); */
1679 if (mdev->state.conn >= C_CONNECTED)
1680 drbd_force_state(mdev,
1681 NS(conn, C_NETWORK_FAILURE));
1682 }
1683 }
1684 D_ASSERT(test_bit(DEVICE_DYING, &mdev->flags));
1685 D_ASSERT(test_bit(CONFIG_PENDING, &mdev->flags));
1686
1687 spin_lock_irq(&mdev->data.work.q_lock);
1688 i = 0;
1689 while (!list_empty(&mdev->data.work.q)) {
1690 list_splice_init(&mdev->data.work.q, &work_list);
1691 spin_unlock_irq(&mdev->data.work.q_lock);
1692
1693 while (!list_empty(&work_list)) {
1694 w = list_entry(work_list.next, struct drbd_work, list);
1695 list_del_init(&w->list);
1696 w->cb(mdev, w, 1);
1697 i++; /* dead debugging code */
1698 }
1699
1700 spin_lock_irq(&mdev->data.work.q_lock);
1701 }
1702 sema_init(&mdev->data.work.s, 0);
1703 /* DANGEROUS race: if someone did queue his work within the spinlock,
1704 * but up() ed outside the spinlock, we could get an up() on the
1705 * semaphore without corresponding list entry.
1706 * So don't do that.
1707 */
1708 spin_unlock_irq(&mdev->data.work.q_lock);
1709
1710 D_ASSERT(mdev->state.disk == D_DISKLESS && mdev->state.conn == C_STANDALONE);
1711 /* _drbd_set_state only uses stop_nowait.
1712 * wait here for the Exiting receiver. */
1713 drbd_thread_stop(&mdev->receiver);
1714 drbd_mdev_cleanup(mdev);
1715
1716 dev_info(DEV, "worker terminated\n");
1717
1718 clear_bit(DEVICE_DYING, &mdev->flags);
1719 clear_bit(CONFIG_PENDING, &mdev->flags);
1720 wake_up(&mdev->state_wait);
1721
1722 return 0;
1723}
1/*
2 drbd_worker.c
3
4 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
5
6 Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
7 Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
8 Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
9
10 drbd is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
13 any later version.
14
15 drbd is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with drbd; see the file COPYING. If not, write to
22 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
23
24*/
25
26#include <linux/module.h>
27#include <linux/drbd.h>
28#include <linux/sched.h>
29#include <linux/wait.h>
30#include <linux/mm.h>
31#include <linux/memcontrol.h>
32#include <linux/mm_inline.h>
33#include <linux/slab.h>
34#include <linux/random.h>
35#include <linux/string.h>
36#include <linux/scatterlist.h>
37
38#include "drbd_int.h"
39#include "drbd_protocol.h"
40#include "drbd_req.h"
41
42static int make_ov_request(struct drbd_device *, int);
43static int make_resync_request(struct drbd_device *, int);
44
45/* endio handlers:
46 * drbd_md_endio (defined here)
47 * drbd_request_endio (defined here)
48 * drbd_peer_request_endio (defined here)
49 * drbd_bm_endio (defined in drbd_bitmap.c)
50 *
51 * For all these callbacks, note the following:
52 * The callbacks will be called in irq context by the IDE drivers,
53 * and in Softirqs/Tasklets/BH context by the SCSI drivers.
54 * Try to get the locking right :)
55 *
56 */
57
58/* used for synchronous meta data and bitmap IO
59 * submitted by drbd_md_sync_page_io()
60 */
61void drbd_md_endio(struct bio *bio)
62{
63 struct drbd_device *device;
64
65 device = bio->bi_private;
66 device->md_io.error = bio->bi_error;
67
68 /* We grabbed an extra reference in _drbd_md_sync_page_io() to be able
69 * to timeout on the lower level device, and eventually detach from it.
70 * If this io completion runs after that timeout expired, this
71 * drbd_md_put_buffer() may allow us to finally try and re-attach.
72 * During normal operation, this only puts that extra reference
73 * down to 1 again.
74 * Make sure we first drop the reference, and only then signal
75 * completion, or we may (in drbd_al_read_log()) cycle so fast into the
76 * next drbd_md_sync_page_io(), that we trigger the
77 * ASSERT(atomic_read(&device->md_io_in_use) == 1) there.
78 */
79 drbd_md_put_buffer(device);
80 device->md_io.done = 1;
81 wake_up(&device->misc_wait);
82 bio_put(bio);
83 if (device->ldev) /* special case: drbd_md_read() during drbd_adm_attach() */
84 put_ldev(device);
85}
86
87/* reads on behalf of the partner,
88 * "submitted" by the receiver
89 */
90static void drbd_endio_read_sec_final(struct drbd_peer_request *peer_req) __releases(local)
91{
92 unsigned long flags = 0;
93 struct drbd_peer_device *peer_device = peer_req->peer_device;
94 struct drbd_device *device = peer_device->device;
95
96 spin_lock_irqsave(&device->resource->req_lock, flags);
97 device->read_cnt += peer_req->i.size >> 9;
98 list_del(&peer_req->w.list);
99 if (list_empty(&device->read_ee))
100 wake_up(&device->ee_wait);
101 if (test_bit(__EE_WAS_ERROR, &peer_req->flags))
102 __drbd_chk_io_error(device, DRBD_READ_ERROR);
103 spin_unlock_irqrestore(&device->resource->req_lock, flags);
104
105 drbd_queue_work(&peer_device->connection->sender_work, &peer_req->w);
106 put_ldev(device);
107}
108
109/* writes on behalf of the partner, or resync writes,
110 * "submitted" by the receiver, final stage. */
111void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req) __releases(local)
112{
113 unsigned long flags = 0;
114 struct drbd_peer_device *peer_device = peer_req->peer_device;
115 struct drbd_device *device = peer_device->device;
116 struct drbd_connection *connection = peer_device->connection;
117 struct drbd_interval i;
118 int do_wake;
119 u64 block_id;
120 int do_al_complete_io;
121
122 /* after we moved peer_req to done_ee,
123 * we may no longer access it,
124 * it may be freed/reused already!
125 * (as soon as we release the req_lock) */
126 i = peer_req->i;
127 do_al_complete_io = peer_req->flags & EE_CALL_AL_COMPLETE_IO;
128 block_id = peer_req->block_id;
129 peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO;
130
131 spin_lock_irqsave(&device->resource->req_lock, flags);
132 device->writ_cnt += peer_req->i.size >> 9;
133 list_move_tail(&peer_req->w.list, &device->done_ee);
134
135 /*
136 * Do not remove from the write_requests tree here: we did not send the
137 * Ack yet and did not wake possibly waiting conflicting requests.
138 * Removed from the tree from "drbd_process_done_ee" within the
139 * appropriate dw.cb (e_end_block/e_end_resync_block) or from
140 * _drbd_clear_done_ee.
141 */
142
143 do_wake = list_empty(block_id == ID_SYNCER ? &device->sync_ee : &device->active_ee);
144
145 /* FIXME do we want to detach for failed REQ_DISCARD?
146 * ((peer_req->flags & (EE_WAS_ERROR|EE_IS_TRIM)) == EE_WAS_ERROR) */
147 if (peer_req->flags & EE_WAS_ERROR)
148 __drbd_chk_io_error(device, DRBD_WRITE_ERROR);
149
150 if (connection->cstate >= C_WF_REPORT_PARAMS) {
151 kref_get(&device->kref); /* put is in drbd_send_acks_wf() */
152 if (!queue_work(connection->ack_sender, &peer_device->send_acks_work))
153 kref_put(&device->kref, drbd_destroy_device);
154 }
155 spin_unlock_irqrestore(&device->resource->req_lock, flags);
156
157 if (block_id == ID_SYNCER)
158 drbd_rs_complete_io(device, i.sector);
159
160 if (do_wake)
161 wake_up(&device->ee_wait);
162
163 if (do_al_complete_io)
164 drbd_al_complete_io(device, &i);
165
166 put_ldev(device);
167}
168
169/* writes on behalf of the partner, or resync writes,
170 * "submitted" by the receiver.
171 */
172void drbd_peer_request_endio(struct bio *bio)
173{
174 struct drbd_peer_request *peer_req = bio->bi_private;
175 struct drbd_device *device = peer_req->peer_device->device;
176 int is_write = bio_data_dir(bio) == WRITE;
177 int is_discard = !!(bio->bi_rw & REQ_DISCARD);
178
179 if (bio->bi_error && __ratelimit(&drbd_ratelimit_state))
180 drbd_warn(device, "%s: error=%d s=%llus\n",
181 is_write ? (is_discard ? "discard" : "write")
182 : "read", bio->bi_error,
183 (unsigned long long)peer_req->i.sector);
184
185 if (bio->bi_error)
186 set_bit(__EE_WAS_ERROR, &peer_req->flags);
187
188 bio_put(bio); /* no need for the bio anymore */
189 if (atomic_dec_and_test(&peer_req->pending_bios)) {
190 if (is_write)
191 drbd_endio_write_sec_final(peer_req);
192 else
193 drbd_endio_read_sec_final(peer_req);
194 }
195}
196
197void drbd_panic_after_delayed_completion_of_aborted_request(struct drbd_device *device)
198{
199 panic("drbd%u %s/%u potential random memory corruption caused by delayed completion of aborted local request\n",
200 device->minor, device->resource->name, device->vnr);
201}
202
203/* read, readA or write requests on R_PRIMARY coming from drbd_make_request
204 */
205void drbd_request_endio(struct bio *bio)
206{
207 unsigned long flags;
208 struct drbd_request *req = bio->bi_private;
209 struct drbd_device *device = req->device;
210 struct bio_and_error m;
211 enum drbd_req_event what;
212
213 /* If this request was aborted locally before,
214 * but now was completed "successfully",
215 * chances are that this caused arbitrary data corruption.
216 *
217 * "aborting" requests, or force-detaching the disk, is intended for
218 * completely blocked/hung local backing devices which do no longer
219 * complete requests at all, not even do error completions. In this
220 * situation, usually a hard-reset and failover is the only way out.
221 *
222 * By "aborting", basically faking a local error-completion,
223 * we allow for a more graceful swichover by cleanly migrating services.
224 * Still the affected node has to be rebooted "soon".
225 *
226 * By completing these requests, we allow the upper layers to re-use
227 * the associated data pages.
228 *
229 * If later the local backing device "recovers", and now DMAs some data
230 * from disk into the original request pages, in the best case it will
231 * just put random data into unused pages; but typically it will corrupt
232 * meanwhile completely unrelated data, causing all sorts of damage.
233 *
234 * Which means delayed successful completion,
235 * especially for READ requests,
236 * is a reason to panic().
237 *
238 * We assume that a delayed *error* completion is OK,
239 * though we still will complain noisily about it.
240 */
241 if (unlikely(req->rq_state & RQ_LOCAL_ABORTED)) {
242 if (__ratelimit(&drbd_ratelimit_state))
243 drbd_emerg(device, "delayed completion of aborted local request; disk-timeout may be too aggressive\n");
244
245 if (!bio->bi_error)
246 drbd_panic_after_delayed_completion_of_aborted_request(device);
247 }
248
249 /* to avoid recursion in __req_mod */
250 if (unlikely(bio->bi_error)) {
251 if (bio->bi_rw & REQ_DISCARD)
252 what = (bio->bi_error == -EOPNOTSUPP)
253 ? DISCARD_COMPLETED_NOTSUPP
254 : DISCARD_COMPLETED_WITH_ERROR;
255 else
256 what = (bio_data_dir(bio) == WRITE)
257 ? WRITE_COMPLETED_WITH_ERROR
258 : (bio_rw(bio) == READ)
259 ? READ_COMPLETED_WITH_ERROR
260 : READ_AHEAD_COMPLETED_WITH_ERROR;
261 } else
262 what = COMPLETED_OK;
263
264 bio_put(req->private_bio);
265 req->private_bio = ERR_PTR(bio->bi_error);
266
267 /* not req_mod(), we need irqsave here! */
268 spin_lock_irqsave(&device->resource->req_lock, flags);
269 __req_mod(req, what, &m);
270 spin_unlock_irqrestore(&device->resource->req_lock, flags);
271 put_ldev(device);
272
273 if (m.bio)
274 complete_master_bio(device, &m);
275}
276
277void drbd_csum_ee(struct crypto_ahash *tfm, struct drbd_peer_request *peer_req, void *digest)
278{
279 AHASH_REQUEST_ON_STACK(req, tfm);
280 struct scatterlist sg;
281 struct page *page = peer_req->pages;
282 struct page *tmp;
283 unsigned len;
284
285 ahash_request_set_tfm(req, tfm);
286 ahash_request_set_callback(req, 0, NULL, NULL);
287
288 sg_init_table(&sg, 1);
289 crypto_ahash_init(req);
290
291 while ((tmp = page_chain_next(page))) {
292 /* all but the last page will be fully used */
293 sg_set_page(&sg, page, PAGE_SIZE, 0);
294 ahash_request_set_crypt(req, &sg, NULL, sg.length);
295 crypto_ahash_update(req);
296 page = tmp;
297 }
298 /* and now the last, possibly only partially used page */
299 len = peer_req->i.size & (PAGE_SIZE - 1);
300 sg_set_page(&sg, page, len ?: PAGE_SIZE, 0);
301 ahash_request_set_crypt(req, &sg, digest, sg.length);
302 crypto_ahash_finup(req);
303 ahash_request_zero(req);
304}
305
306void drbd_csum_bio(struct crypto_ahash *tfm, struct bio *bio, void *digest)
307{
308 AHASH_REQUEST_ON_STACK(req, tfm);
309 struct scatterlist sg;
310 struct bio_vec bvec;
311 struct bvec_iter iter;
312
313 ahash_request_set_tfm(req, tfm);
314 ahash_request_set_callback(req, 0, NULL, NULL);
315
316 sg_init_table(&sg, 1);
317 crypto_ahash_init(req);
318
319 bio_for_each_segment(bvec, bio, iter) {
320 sg_set_page(&sg, bvec.bv_page, bvec.bv_len, bvec.bv_offset);
321 ahash_request_set_crypt(req, &sg, NULL, sg.length);
322 crypto_ahash_update(req);
323 }
324 ahash_request_set_crypt(req, NULL, digest, 0);
325 crypto_ahash_final(req);
326 ahash_request_zero(req);
327}
328
329/* MAYBE merge common code with w_e_end_ov_req */
330static int w_e_send_csum(struct drbd_work *w, int cancel)
331{
332 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w);
333 struct drbd_peer_device *peer_device = peer_req->peer_device;
334 struct drbd_device *device = peer_device->device;
335 int digest_size;
336 void *digest;
337 int err = 0;
338
339 if (unlikely(cancel))
340 goto out;
341
342 if (unlikely((peer_req->flags & EE_WAS_ERROR) != 0))
343 goto out;
344
345 digest_size = crypto_ahash_digestsize(peer_device->connection->csums_tfm);
346 digest = kmalloc(digest_size, GFP_NOIO);
347 if (digest) {
348 sector_t sector = peer_req->i.sector;
349 unsigned int size = peer_req->i.size;
350 drbd_csum_ee(peer_device->connection->csums_tfm, peer_req, digest);
351 /* Free peer_req and pages before send.
352 * In case we block on congestion, we could otherwise run into
353 * some distributed deadlock, if the other side blocks on
354 * congestion as well, because our receiver blocks in
355 * drbd_alloc_pages due to pp_in_use > max_buffers. */
356 drbd_free_peer_req(device, peer_req);
357 peer_req = NULL;
358 inc_rs_pending(device);
359 err = drbd_send_drequest_csum(peer_device, sector, size,
360 digest, digest_size,
361 P_CSUM_RS_REQUEST);
362 kfree(digest);
363 } else {
364 drbd_err(device, "kmalloc() of digest failed.\n");
365 err = -ENOMEM;
366 }
367
368out:
369 if (peer_req)
370 drbd_free_peer_req(device, peer_req);
371
372 if (unlikely(err))
373 drbd_err(device, "drbd_send_drequest(..., csum) failed\n");
374 return err;
375}
376
377#define GFP_TRY (__GFP_HIGHMEM | __GFP_NOWARN)
378
379static int read_for_csum(struct drbd_peer_device *peer_device, sector_t sector, int size)
380{
381 struct drbd_device *device = peer_device->device;
382 struct drbd_peer_request *peer_req;
383
384 if (!get_ldev(device))
385 return -EIO;
386
387 /* GFP_TRY, because if there is no memory available right now, this may
388 * be rescheduled for later. It is "only" background resync, after all. */
389 peer_req = drbd_alloc_peer_req(peer_device, ID_SYNCER /* unused */, sector,
390 size, true /* has real payload */, GFP_TRY);
391 if (!peer_req)
392 goto defer;
393
394 peer_req->w.cb = w_e_send_csum;
395 spin_lock_irq(&device->resource->req_lock);
396 list_add_tail(&peer_req->w.list, &device->read_ee);
397 spin_unlock_irq(&device->resource->req_lock);
398
399 atomic_add(size >> 9, &device->rs_sect_ev);
400 if (drbd_submit_peer_request(device, peer_req, READ, DRBD_FAULT_RS_RD) == 0)
401 return 0;
402
403 /* If it failed because of ENOMEM, retry should help. If it failed
404 * because bio_add_page failed (probably broken lower level driver),
405 * retry may or may not help.
406 * If it does not, you may need to force disconnect. */
407 spin_lock_irq(&device->resource->req_lock);
408 list_del(&peer_req->w.list);
409 spin_unlock_irq(&device->resource->req_lock);
410
411 drbd_free_peer_req(device, peer_req);
412defer:
413 put_ldev(device);
414 return -EAGAIN;
415}
416
417int w_resync_timer(struct drbd_work *w, int cancel)
418{
419 struct drbd_device *device =
420 container_of(w, struct drbd_device, resync_work);
421
422 switch (device->state.conn) {
423 case C_VERIFY_S:
424 make_ov_request(device, cancel);
425 break;
426 case C_SYNC_TARGET:
427 make_resync_request(device, cancel);
428 break;
429 }
430
431 return 0;
432}
433
434void resync_timer_fn(unsigned long data)
435{
436 struct drbd_device *device = (struct drbd_device *) data;
437
438 drbd_queue_work_if_unqueued(
439 &first_peer_device(device)->connection->sender_work,
440 &device->resync_work);
441}
442
443static void fifo_set(struct fifo_buffer *fb, int value)
444{
445 int i;
446
447 for (i = 0; i < fb->size; i++)
448 fb->values[i] = value;
449}
450
451static int fifo_push(struct fifo_buffer *fb, int value)
452{
453 int ov;
454
455 ov = fb->values[fb->head_index];
456 fb->values[fb->head_index++] = value;
457
458 if (fb->head_index >= fb->size)
459 fb->head_index = 0;
460
461 return ov;
462}
463
464static void fifo_add_val(struct fifo_buffer *fb, int value)
465{
466 int i;
467
468 for (i = 0; i < fb->size; i++)
469 fb->values[i] += value;
470}
471
472struct fifo_buffer *fifo_alloc(int fifo_size)
473{
474 struct fifo_buffer *fb;
475
476 fb = kzalloc(sizeof(struct fifo_buffer) + sizeof(int) * fifo_size, GFP_NOIO);
477 if (!fb)
478 return NULL;
479
480 fb->head_index = 0;
481 fb->size = fifo_size;
482 fb->total = 0;
483
484 return fb;
485}
486
487static int drbd_rs_controller(struct drbd_device *device, unsigned int sect_in)
488{
489 struct disk_conf *dc;
490 unsigned int want; /* The number of sectors we want in-flight */
491 int req_sect; /* Number of sectors to request in this turn */
492 int correction; /* Number of sectors more we need in-flight */
493 int cps; /* correction per invocation of drbd_rs_controller() */
494 int steps; /* Number of time steps to plan ahead */
495 int curr_corr;
496 int max_sect;
497 struct fifo_buffer *plan;
498
499 dc = rcu_dereference(device->ldev->disk_conf);
500 plan = rcu_dereference(device->rs_plan_s);
501
502 steps = plan->size; /* (dc->c_plan_ahead * 10 * SLEEP_TIME) / HZ; */
503
504 if (device->rs_in_flight + sect_in == 0) { /* At start of resync */
505 want = ((dc->resync_rate * 2 * SLEEP_TIME) / HZ) * steps;
506 } else { /* normal path */
507 want = dc->c_fill_target ? dc->c_fill_target :
508 sect_in * dc->c_delay_target * HZ / (SLEEP_TIME * 10);
509 }
510
511 correction = want - device->rs_in_flight - plan->total;
512
513 /* Plan ahead */
514 cps = correction / steps;
515 fifo_add_val(plan, cps);
516 plan->total += cps * steps;
517
518 /* What we do in this step */
519 curr_corr = fifo_push(plan, 0);
520 plan->total -= curr_corr;
521
522 req_sect = sect_in + curr_corr;
523 if (req_sect < 0)
524 req_sect = 0;
525
526 max_sect = (dc->c_max_rate * 2 * SLEEP_TIME) / HZ;
527 if (req_sect > max_sect)
528 req_sect = max_sect;
529
530 /*
531 drbd_warn(device, "si=%u if=%d wa=%u co=%d st=%d cps=%d pl=%d cc=%d rs=%d\n",
532 sect_in, device->rs_in_flight, want, correction,
533 steps, cps, device->rs_planed, curr_corr, req_sect);
534 */
535
536 return req_sect;
537}
538
539static int drbd_rs_number_requests(struct drbd_device *device)
540{
541 unsigned int sect_in; /* Number of sectors that came in since the last turn */
542 int number, mxb;
543
544 sect_in = atomic_xchg(&device->rs_sect_in, 0);
545 device->rs_in_flight -= sect_in;
546
547 rcu_read_lock();
548 mxb = drbd_get_max_buffers(device) / 2;
549 if (rcu_dereference(device->rs_plan_s)->size) {
550 number = drbd_rs_controller(device, sect_in) >> (BM_BLOCK_SHIFT - 9);
551 device->c_sync_rate = number * HZ * (BM_BLOCK_SIZE / 1024) / SLEEP_TIME;
552 } else {
553 device->c_sync_rate = rcu_dereference(device->ldev->disk_conf)->resync_rate;
554 number = SLEEP_TIME * device->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ);
555 }
556 rcu_read_unlock();
557
558 /* Don't have more than "max-buffers"/2 in-flight.
559 * Otherwise we may cause the remote site to stall on drbd_alloc_pages(),
560 * potentially causing a distributed deadlock on congestion during
561 * online-verify or (checksum-based) resync, if max-buffers,
562 * socket buffer sizes and resync rate settings are mis-configured. */
563
564 /* note that "number" is in units of "BM_BLOCK_SIZE" (which is 4k),
565 * mxb (as used here, and in drbd_alloc_pages on the peer) is
566 * "number of pages" (typically also 4k),
567 * but "rs_in_flight" is in "sectors" (512 Byte). */
568 if (mxb - device->rs_in_flight/8 < number)
569 number = mxb - device->rs_in_flight/8;
570
571 return number;
572}
573
574static int make_resync_request(struct drbd_device *const device, int cancel)
575{
576 struct drbd_peer_device *const peer_device = first_peer_device(device);
577 struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL;
578 unsigned long bit;
579 sector_t sector;
580 const sector_t capacity = drbd_get_capacity(device->this_bdev);
581 int max_bio_size;
582 int number, rollback_i, size;
583 int align, requeue = 0;
584 int i = 0;
585
586 if (unlikely(cancel))
587 return 0;
588
589 if (device->rs_total == 0) {
590 /* empty resync? */
591 drbd_resync_finished(device);
592 return 0;
593 }
594
595 if (!get_ldev(device)) {
596 /* Since we only need to access device->rsync a
597 get_ldev_if_state(device,D_FAILED) would be sufficient, but
598 to continue resync with a broken disk makes no sense at
599 all */
600 drbd_err(device, "Disk broke down during resync!\n");
601 return 0;
602 }
603
604 max_bio_size = queue_max_hw_sectors(device->rq_queue) << 9;
605 number = drbd_rs_number_requests(device);
606 if (number <= 0)
607 goto requeue;
608
609 for (i = 0; i < number; i++) {
610 /* Stop generating RS requests when half of the send buffer is filled,
611 * but notify TCP that we'd like to have more space. */
612 mutex_lock(&connection->data.mutex);
613 if (connection->data.socket) {
614 struct sock *sk = connection->data.socket->sk;
615 int queued = sk->sk_wmem_queued;
616 int sndbuf = sk->sk_sndbuf;
617 if (queued > sndbuf / 2) {
618 requeue = 1;
619 if (sk->sk_socket)
620 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
621 }
622 } else
623 requeue = 1;
624 mutex_unlock(&connection->data.mutex);
625 if (requeue)
626 goto requeue;
627
628next_sector:
629 size = BM_BLOCK_SIZE;
630 bit = drbd_bm_find_next(device, device->bm_resync_fo);
631
632 if (bit == DRBD_END_OF_BITMAP) {
633 device->bm_resync_fo = drbd_bm_bits(device);
634 put_ldev(device);
635 return 0;
636 }
637
638 sector = BM_BIT_TO_SECT(bit);
639
640 if (drbd_try_rs_begin_io(device, sector)) {
641 device->bm_resync_fo = bit;
642 goto requeue;
643 }
644 device->bm_resync_fo = bit + 1;
645
646 if (unlikely(drbd_bm_test_bit(device, bit) == 0)) {
647 drbd_rs_complete_io(device, sector);
648 goto next_sector;
649 }
650
651#if DRBD_MAX_BIO_SIZE > BM_BLOCK_SIZE
652 /* try to find some adjacent bits.
653 * we stop if we have already the maximum req size.
654 *
655 * Additionally always align bigger requests, in order to
656 * be prepared for all stripe sizes of software RAIDs.
657 */
658 align = 1;
659 rollback_i = i;
660 while (i < number) {
661 if (size + BM_BLOCK_SIZE > max_bio_size)
662 break;
663
664 /* Be always aligned */
665 if (sector & ((1<<(align+3))-1))
666 break;
667
668 /* do not cross extent boundaries */
669 if (((bit+1) & BM_BLOCKS_PER_BM_EXT_MASK) == 0)
670 break;
671 /* now, is it actually dirty, after all?
672 * caution, drbd_bm_test_bit is tri-state for some
673 * obscure reason; ( b == 0 ) would get the out-of-band
674 * only accidentally right because of the "oddly sized"
675 * adjustment below */
676 if (drbd_bm_test_bit(device, bit+1) != 1)
677 break;
678 bit++;
679 size += BM_BLOCK_SIZE;
680 if ((BM_BLOCK_SIZE << align) <= size)
681 align++;
682 i++;
683 }
684 /* if we merged some,
685 * reset the offset to start the next drbd_bm_find_next from */
686 if (size > BM_BLOCK_SIZE)
687 device->bm_resync_fo = bit + 1;
688#endif
689
690 /* adjust very last sectors, in case we are oddly sized */
691 if (sector + (size>>9) > capacity)
692 size = (capacity-sector)<<9;
693
694 if (device->use_csums) {
695 switch (read_for_csum(peer_device, sector, size)) {
696 case -EIO: /* Disk failure */
697 put_ldev(device);
698 return -EIO;
699 case -EAGAIN: /* allocation failed, or ldev busy */
700 drbd_rs_complete_io(device, sector);
701 device->bm_resync_fo = BM_SECT_TO_BIT(sector);
702 i = rollback_i;
703 goto requeue;
704 case 0:
705 /* everything ok */
706 break;
707 default:
708 BUG();
709 }
710 } else {
711 int err;
712
713 inc_rs_pending(device);
714 err = drbd_send_drequest(peer_device, P_RS_DATA_REQUEST,
715 sector, size, ID_SYNCER);
716 if (err) {
717 drbd_err(device, "drbd_send_drequest() failed, aborting...\n");
718 dec_rs_pending(device);
719 put_ldev(device);
720 return err;
721 }
722 }
723 }
724
725 if (device->bm_resync_fo >= drbd_bm_bits(device)) {
726 /* last syncer _request_ was sent,
727 * but the P_RS_DATA_REPLY not yet received. sync will end (and
728 * next sync group will resume), as soon as we receive the last
729 * resync data block, and the last bit is cleared.
730 * until then resync "work" is "inactive" ...
731 */
732 put_ldev(device);
733 return 0;
734 }
735
736 requeue:
737 device->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9));
738 mod_timer(&device->resync_timer, jiffies + SLEEP_TIME);
739 put_ldev(device);
740 return 0;
741}
742
743static int make_ov_request(struct drbd_device *device, int cancel)
744{
745 int number, i, size;
746 sector_t sector;
747 const sector_t capacity = drbd_get_capacity(device->this_bdev);
748 bool stop_sector_reached = false;
749
750 if (unlikely(cancel))
751 return 1;
752
753 number = drbd_rs_number_requests(device);
754
755 sector = device->ov_position;
756 for (i = 0; i < number; i++) {
757 if (sector >= capacity)
758 return 1;
759
760 /* We check for "finished" only in the reply path:
761 * w_e_end_ov_reply().
762 * We need to send at least one request out. */
763 stop_sector_reached = i > 0
764 && verify_can_do_stop_sector(device)
765 && sector >= device->ov_stop_sector;
766 if (stop_sector_reached)
767 break;
768
769 size = BM_BLOCK_SIZE;
770
771 if (drbd_try_rs_begin_io(device, sector)) {
772 device->ov_position = sector;
773 goto requeue;
774 }
775
776 if (sector + (size>>9) > capacity)
777 size = (capacity-sector)<<9;
778
779 inc_rs_pending(device);
780 if (drbd_send_ov_request(first_peer_device(device), sector, size)) {
781 dec_rs_pending(device);
782 return 0;
783 }
784 sector += BM_SECT_PER_BIT;
785 }
786 device->ov_position = sector;
787
788 requeue:
789 device->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9));
790 if (i == 0 || !stop_sector_reached)
791 mod_timer(&device->resync_timer, jiffies + SLEEP_TIME);
792 return 1;
793}
794
795int w_ov_finished(struct drbd_work *w, int cancel)
796{
797 struct drbd_device_work *dw =
798 container_of(w, struct drbd_device_work, w);
799 struct drbd_device *device = dw->device;
800 kfree(dw);
801 ov_out_of_sync_print(device);
802 drbd_resync_finished(device);
803
804 return 0;
805}
806
807static int w_resync_finished(struct drbd_work *w, int cancel)
808{
809 struct drbd_device_work *dw =
810 container_of(w, struct drbd_device_work, w);
811 struct drbd_device *device = dw->device;
812 kfree(dw);
813
814 drbd_resync_finished(device);
815
816 return 0;
817}
818
819static void ping_peer(struct drbd_device *device)
820{
821 struct drbd_connection *connection = first_peer_device(device)->connection;
822
823 clear_bit(GOT_PING_ACK, &connection->flags);
824 request_ping(connection);
825 wait_event(connection->ping_wait,
826 test_bit(GOT_PING_ACK, &connection->flags) || device->state.conn < C_CONNECTED);
827}
828
829int drbd_resync_finished(struct drbd_device *device)
830{
831 unsigned long db, dt, dbdt;
832 unsigned long n_oos;
833 union drbd_state os, ns;
834 struct drbd_device_work *dw;
835 char *khelper_cmd = NULL;
836 int verify_done = 0;
837
838 /* Remove all elements from the resync LRU. Since future actions
839 * might set bits in the (main) bitmap, then the entries in the
840 * resync LRU would be wrong. */
841 if (drbd_rs_del_all(device)) {
842 /* In case this is not possible now, most probably because
843 * there are P_RS_DATA_REPLY Packets lingering on the worker's
844 * queue (or even the read operations for those packets
845 * is not finished by now). Retry in 100ms. */
846
847 schedule_timeout_interruptible(HZ / 10);
848 dw = kmalloc(sizeof(struct drbd_device_work), GFP_ATOMIC);
849 if (dw) {
850 dw->w.cb = w_resync_finished;
851 dw->device = device;
852 drbd_queue_work(&first_peer_device(device)->connection->sender_work,
853 &dw->w);
854 return 1;
855 }
856 drbd_err(device, "Warn failed to drbd_rs_del_all() and to kmalloc(dw).\n");
857 }
858
859 dt = (jiffies - device->rs_start - device->rs_paused) / HZ;
860 if (dt <= 0)
861 dt = 1;
862
863 db = device->rs_total;
864 /* adjust for verify start and stop sectors, respective reached position */
865 if (device->state.conn == C_VERIFY_S || device->state.conn == C_VERIFY_T)
866 db -= device->ov_left;
867
868 dbdt = Bit2KB(db/dt);
869 device->rs_paused /= HZ;
870
871 if (!get_ldev(device))
872 goto out;
873
874 ping_peer(device);
875
876 spin_lock_irq(&device->resource->req_lock);
877 os = drbd_read_state(device);
878
879 verify_done = (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T);
880
881 /* This protects us against multiple calls (that can happen in the presence
882 of application IO), and against connectivity loss just before we arrive here. */
883 if (os.conn <= C_CONNECTED)
884 goto out_unlock;
885
886 ns = os;
887 ns.conn = C_CONNECTED;
888
889 drbd_info(device, "%s done (total %lu sec; paused %lu sec; %lu K/sec)\n",
890 verify_done ? "Online verify" : "Resync",
891 dt + device->rs_paused, device->rs_paused, dbdt);
892
893 n_oos = drbd_bm_total_weight(device);
894
895 if (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) {
896 if (n_oos) {
897 drbd_alert(device, "Online verify found %lu %dk block out of sync!\n",
898 n_oos, Bit2KB(1));
899 khelper_cmd = "out-of-sync";
900 }
901 } else {
902 D_ASSERT(device, (n_oos - device->rs_failed) == 0);
903
904 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T)
905 khelper_cmd = "after-resync-target";
906
907 if (device->use_csums && device->rs_total) {
908 const unsigned long s = device->rs_same_csum;
909 const unsigned long t = device->rs_total;
910 const int ratio =
911 (t == 0) ? 0 :
912 (t < 100000) ? ((s*100)/t) : (s/(t/100));
913 drbd_info(device, "%u %% had equal checksums, eliminated: %luK; "
914 "transferred %luK total %luK\n",
915 ratio,
916 Bit2KB(device->rs_same_csum),
917 Bit2KB(device->rs_total - device->rs_same_csum),
918 Bit2KB(device->rs_total));
919 }
920 }
921
922 if (device->rs_failed) {
923 drbd_info(device, " %lu failed blocks\n", device->rs_failed);
924
925 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) {
926 ns.disk = D_INCONSISTENT;
927 ns.pdsk = D_UP_TO_DATE;
928 } else {
929 ns.disk = D_UP_TO_DATE;
930 ns.pdsk = D_INCONSISTENT;
931 }
932 } else {
933 ns.disk = D_UP_TO_DATE;
934 ns.pdsk = D_UP_TO_DATE;
935
936 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) {
937 if (device->p_uuid) {
938 int i;
939 for (i = UI_BITMAP ; i <= UI_HISTORY_END ; i++)
940 _drbd_uuid_set(device, i, device->p_uuid[i]);
941 drbd_uuid_set(device, UI_BITMAP, device->ldev->md.uuid[UI_CURRENT]);
942 _drbd_uuid_set(device, UI_CURRENT, device->p_uuid[UI_CURRENT]);
943 } else {
944 drbd_err(device, "device->p_uuid is NULL! BUG\n");
945 }
946 }
947
948 if (!(os.conn == C_VERIFY_S || os.conn == C_VERIFY_T)) {
949 /* for verify runs, we don't update uuids here,
950 * so there would be nothing to report. */
951 drbd_uuid_set_bm(device, 0UL);
952 drbd_print_uuids(device, "updated UUIDs");
953 if (device->p_uuid) {
954 /* Now the two UUID sets are equal, update what we
955 * know of the peer. */
956 int i;
957 for (i = UI_CURRENT ; i <= UI_HISTORY_END ; i++)
958 device->p_uuid[i] = device->ldev->md.uuid[i];
959 }
960 }
961 }
962
963 _drbd_set_state(device, ns, CS_VERBOSE, NULL);
964out_unlock:
965 spin_unlock_irq(&device->resource->req_lock);
966 put_ldev(device);
967out:
968 device->rs_total = 0;
969 device->rs_failed = 0;
970 device->rs_paused = 0;
971
972 /* reset start sector, if we reached end of device */
973 if (verify_done && device->ov_left == 0)
974 device->ov_start_sector = 0;
975
976 drbd_md_sync(device);
977
978 if (khelper_cmd)
979 drbd_khelper(device, khelper_cmd);
980
981 return 1;
982}
983
984/* helper */
985static void move_to_net_ee_or_free(struct drbd_device *device, struct drbd_peer_request *peer_req)
986{
987 if (drbd_peer_req_has_active_page(peer_req)) {
988 /* This might happen if sendpage() has not finished */
989 int i = (peer_req->i.size + PAGE_SIZE -1) >> PAGE_SHIFT;
990 atomic_add(i, &device->pp_in_use_by_net);
991 atomic_sub(i, &device->pp_in_use);
992 spin_lock_irq(&device->resource->req_lock);
993 list_add_tail(&peer_req->w.list, &device->net_ee);
994 spin_unlock_irq(&device->resource->req_lock);
995 wake_up(&drbd_pp_wait);
996 } else
997 drbd_free_peer_req(device, peer_req);
998}
999
1000/**
1001 * w_e_end_data_req() - Worker callback, to send a P_DATA_REPLY packet in response to a P_DATA_REQUEST
1002 * @device: DRBD device.
1003 * @w: work object.
1004 * @cancel: The connection will be closed anyways
1005 */
1006int w_e_end_data_req(struct drbd_work *w, int cancel)
1007{
1008 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w);
1009 struct drbd_peer_device *peer_device = peer_req->peer_device;
1010 struct drbd_device *device = peer_device->device;
1011 int err;
1012
1013 if (unlikely(cancel)) {
1014 drbd_free_peer_req(device, peer_req);
1015 dec_unacked(device);
1016 return 0;
1017 }
1018
1019 if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
1020 err = drbd_send_block(peer_device, P_DATA_REPLY, peer_req);
1021 } else {
1022 if (__ratelimit(&drbd_ratelimit_state))
1023 drbd_err(device, "Sending NegDReply. sector=%llus.\n",
1024 (unsigned long long)peer_req->i.sector);
1025
1026 err = drbd_send_ack(peer_device, P_NEG_DREPLY, peer_req);
1027 }
1028
1029 dec_unacked(device);
1030
1031 move_to_net_ee_or_free(device, peer_req);
1032
1033 if (unlikely(err))
1034 drbd_err(device, "drbd_send_block() failed\n");
1035 return err;
1036}
1037
1038/**
1039 * w_e_end_rsdata_req() - Worker callback to send a P_RS_DATA_REPLY packet in response to a P_RS_DATA_REQUEST
1040 * @w: work object.
1041 * @cancel: The connection will be closed anyways
1042 */
1043int w_e_end_rsdata_req(struct drbd_work *w, int cancel)
1044{
1045 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w);
1046 struct drbd_peer_device *peer_device = peer_req->peer_device;
1047 struct drbd_device *device = peer_device->device;
1048 int err;
1049
1050 if (unlikely(cancel)) {
1051 drbd_free_peer_req(device, peer_req);
1052 dec_unacked(device);
1053 return 0;
1054 }
1055
1056 if (get_ldev_if_state(device, D_FAILED)) {
1057 drbd_rs_complete_io(device, peer_req->i.sector);
1058 put_ldev(device);
1059 }
1060
1061 if (device->state.conn == C_AHEAD) {
1062 err = drbd_send_ack(peer_device, P_RS_CANCEL, peer_req);
1063 } else if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
1064 if (likely(device->state.pdsk >= D_INCONSISTENT)) {
1065 inc_rs_pending(device);
1066 err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req);
1067 } else {
1068 if (__ratelimit(&drbd_ratelimit_state))
1069 drbd_err(device, "Not sending RSDataReply, "
1070 "partner DISKLESS!\n");
1071 err = 0;
1072 }
1073 } else {
1074 if (__ratelimit(&drbd_ratelimit_state))
1075 drbd_err(device, "Sending NegRSDReply. sector %llus.\n",
1076 (unsigned long long)peer_req->i.sector);
1077
1078 err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req);
1079
1080 /* update resync data with failure */
1081 drbd_rs_failed_io(device, peer_req->i.sector, peer_req->i.size);
1082 }
1083
1084 dec_unacked(device);
1085
1086 move_to_net_ee_or_free(device, peer_req);
1087
1088 if (unlikely(err))
1089 drbd_err(device, "drbd_send_block() failed\n");
1090 return err;
1091}
1092
1093int w_e_end_csum_rs_req(struct drbd_work *w, int cancel)
1094{
1095 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w);
1096 struct drbd_peer_device *peer_device = peer_req->peer_device;
1097 struct drbd_device *device = peer_device->device;
1098 struct digest_info *di;
1099 int digest_size;
1100 void *digest = NULL;
1101 int err, eq = 0;
1102
1103 if (unlikely(cancel)) {
1104 drbd_free_peer_req(device, peer_req);
1105 dec_unacked(device);
1106 return 0;
1107 }
1108
1109 if (get_ldev(device)) {
1110 drbd_rs_complete_io(device, peer_req->i.sector);
1111 put_ldev(device);
1112 }
1113
1114 di = peer_req->digest;
1115
1116 if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
1117 /* quick hack to try to avoid a race against reconfiguration.
1118 * a real fix would be much more involved,
1119 * introducing more locking mechanisms */
1120 if (peer_device->connection->csums_tfm) {
1121 digest_size = crypto_ahash_digestsize(peer_device->connection->csums_tfm);
1122 D_ASSERT(device, digest_size == di->digest_size);
1123 digest = kmalloc(digest_size, GFP_NOIO);
1124 }
1125 if (digest) {
1126 drbd_csum_ee(peer_device->connection->csums_tfm, peer_req, digest);
1127 eq = !memcmp(digest, di->digest, digest_size);
1128 kfree(digest);
1129 }
1130
1131 if (eq) {
1132 drbd_set_in_sync(device, peer_req->i.sector, peer_req->i.size);
1133 /* rs_same_csums unit is BM_BLOCK_SIZE */
1134 device->rs_same_csum += peer_req->i.size >> BM_BLOCK_SHIFT;
1135 err = drbd_send_ack(peer_device, P_RS_IS_IN_SYNC, peer_req);
1136 } else {
1137 inc_rs_pending(device);
1138 peer_req->block_id = ID_SYNCER; /* By setting block_id, digest pointer becomes invalid! */
1139 peer_req->flags &= ~EE_HAS_DIGEST; /* This peer request no longer has a digest pointer */
1140 kfree(di);
1141 err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req);
1142 }
1143 } else {
1144 err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req);
1145 if (__ratelimit(&drbd_ratelimit_state))
1146 drbd_err(device, "Sending NegDReply. I guess it gets messy.\n");
1147 }
1148
1149 dec_unacked(device);
1150 move_to_net_ee_or_free(device, peer_req);
1151
1152 if (unlikely(err))
1153 drbd_err(device, "drbd_send_block/ack() failed\n");
1154 return err;
1155}
1156
1157int w_e_end_ov_req(struct drbd_work *w, int cancel)
1158{
1159 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w);
1160 struct drbd_peer_device *peer_device = peer_req->peer_device;
1161 struct drbd_device *device = peer_device->device;
1162 sector_t sector = peer_req->i.sector;
1163 unsigned int size = peer_req->i.size;
1164 int digest_size;
1165 void *digest;
1166 int err = 0;
1167
1168 if (unlikely(cancel))
1169 goto out;
1170
1171 digest_size = crypto_ahash_digestsize(peer_device->connection->verify_tfm);
1172 digest = kmalloc(digest_size, GFP_NOIO);
1173 if (!digest) {
1174 err = 1; /* terminate the connection in case the allocation failed */
1175 goto out;
1176 }
1177
1178 if (likely(!(peer_req->flags & EE_WAS_ERROR)))
1179 drbd_csum_ee(peer_device->connection->verify_tfm, peer_req, digest);
1180 else
1181 memset(digest, 0, digest_size);
1182
1183 /* Free e and pages before send.
1184 * In case we block on congestion, we could otherwise run into
1185 * some distributed deadlock, if the other side blocks on
1186 * congestion as well, because our receiver blocks in
1187 * drbd_alloc_pages due to pp_in_use > max_buffers. */
1188 drbd_free_peer_req(device, peer_req);
1189 peer_req = NULL;
1190 inc_rs_pending(device);
1191 err = drbd_send_drequest_csum(peer_device, sector, size, digest, digest_size, P_OV_REPLY);
1192 if (err)
1193 dec_rs_pending(device);
1194 kfree(digest);
1195
1196out:
1197 if (peer_req)
1198 drbd_free_peer_req(device, peer_req);
1199 dec_unacked(device);
1200 return err;
1201}
1202
1203void drbd_ov_out_of_sync_found(struct drbd_device *device, sector_t sector, int size)
1204{
1205 if (device->ov_last_oos_start + device->ov_last_oos_size == sector) {
1206 device->ov_last_oos_size += size>>9;
1207 } else {
1208 device->ov_last_oos_start = sector;
1209 device->ov_last_oos_size = size>>9;
1210 }
1211 drbd_set_out_of_sync(device, sector, size);
1212}
1213
1214int w_e_end_ov_reply(struct drbd_work *w, int cancel)
1215{
1216 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w);
1217 struct drbd_peer_device *peer_device = peer_req->peer_device;
1218 struct drbd_device *device = peer_device->device;
1219 struct digest_info *di;
1220 void *digest;
1221 sector_t sector = peer_req->i.sector;
1222 unsigned int size = peer_req->i.size;
1223 int digest_size;
1224 int err, eq = 0;
1225 bool stop_sector_reached = false;
1226
1227 if (unlikely(cancel)) {
1228 drbd_free_peer_req(device, peer_req);
1229 dec_unacked(device);
1230 return 0;
1231 }
1232
1233 /* after "cancel", because after drbd_disconnect/drbd_rs_cancel_all
1234 * the resync lru has been cleaned up already */
1235 if (get_ldev(device)) {
1236 drbd_rs_complete_io(device, peer_req->i.sector);
1237 put_ldev(device);
1238 }
1239
1240 di = peer_req->digest;
1241
1242 if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
1243 digest_size = crypto_ahash_digestsize(peer_device->connection->verify_tfm);
1244 digest = kmalloc(digest_size, GFP_NOIO);
1245 if (digest) {
1246 drbd_csum_ee(peer_device->connection->verify_tfm, peer_req, digest);
1247
1248 D_ASSERT(device, digest_size == di->digest_size);
1249 eq = !memcmp(digest, di->digest, digest_size);
1250 kfree(digest);
1251 }
1252 }
1253
1254 /* Free peer_req and pages before send.
1255 * In case we block on congestion, we could otherwise run into
1256 * some distributed deadlock, if the other side blocks on
1257 * congestion as well, because our receiver blocks in
1258 * drbd_alloc_pages due to pp_in_use > max_buffers. */
1259 drbd_free_peer_req(device, peer_req);
1260 if (!eq)
1261 drbd_ov_out_of_sync_found(device, sector, size);
1262 else
1263 ov_out_of_sync_print(device);
1264
1265 err = drbd_send_ack_ex(peer_device, P_OV_RESULT, sector, size,
1266 eq ? ID_IN_SYNC : ID_OUT_OF_SYNC);
1267
1268 dec_unacked(device);
1269
1270 --device->ov_left;
1271
1272 /* let's advance progress step marks only for every other megabyte */
1273 if ((device->ov_left & 0x200) == 0x200)
1274 drbd_advance_rs_marks(device, device->ov_left);
1275
1276 stop_sector_reached = verify_can_do_stop_sector(device) &&
1277 (sector + (size>>9)) >= device->ov_stop_sector;
1278
1279 if (device->ov_left == 0 || stop_sector_reached) {
1280 ov_out_of_sync_print(device);
1281 drbd_resync_finished(device);
1282 }
1283
1284 return err;
1285}
1286
1287/* FIXME
1288 * We need to track the number of pending barrier acks,
1289 * and to be able to wait for them.
1290 * See also comment in drbd_adm_attach before drbd_suspend_io.
1291 */
1292static int drbd_send_barrier(struct drbd_connection *connection)
1293{
1294 struct p_barrier *p;
1295 struct drbd_socket *sock;
1296
1297 sock = &connection->data;
1298 p = conn_prepare_command(connection, sock);
1299 if (!p)
1300 return -EIO;
1301 p->barrier = connection->send.current_epoch_nr;
1302 p->pad = 0;
1303 connection->send.current_epoch_writes = 0;
1304 connection->send.last_sent_barrier_jif = jiffies;
1305
1306 return conn_send_command(connection, sock, P_BARRIER, sizeof(*p), NULL, 0);
1307}
1308
1309int w_send_write_hint(struct drbd_work *w, int cancel)
1310{
1311 struct drbd_device *device =
1312 container_of(w, struct drbd_device, unplug_work);
1313 struct drbd_socket *sock;
1314
1315 if (cancel)
1316 return 0;
1317 sock = &first_peer_device(device)->connection->data;
1318 if (!drbd_prepare_command(first_peer_device(device), sock))
1319 return -EIO;
1320 return drbd_send_command(first_peer_device(device), sock, P_UNPLUG_REMOTE, 0, NULL, 0);
1321}
1322
1323static void re_init_if_first_write(struct drbd_connection *connection, unsigned int epoch)
1324{
1325 if (!connection->send.seen_any_write_yet) {
1326 connection->send.seen_any_write_yet = true;
1327 connection->send.current_epoch_nr = epoch;
1328 connection->send.current_epoch_writes = 0;
1329 connection->send.last_sent_barrier_jif = jiffies;
1330 }
1331}
1332
1333static void maybe_send_barrier(struct drbd_connection *connection, unsigned int epoch)
1334{
1335 /* re-init if first write on this connection */
1336 if (!connection->send.seen_any_write_yet)
1337 return;
1338 if (connection->send.current_epoch_nr != epoch) {
1339 if (connection->send.current_epoch_writes)
1340 drbd_send_barrier(connection);
1341 connection->send.current_epoch_nr = epoch;
1342 }
1343}
1344
1345int w_send_out_of_sync(struct drbd_work *w, int cancel)
1346{
1347 struct drbd_request *req = container_of(w, struct drbd_request, w);
1348 struct drbd_device *device = req->device;
1349 struct drbd_peer_device *const peer_device = first_peer_device(device);
1350 struct drbd_connection *const connection = peer_device->connection;
1351 int err;
1352
1353 if (unlikely(cancel)) {
1354 req_mod(req, SEND_CANCELED);
1355 return 0;
1356 }
1357 req->pre_send_jif = jiffies;
1358
1359 /* this time, no connection->send.current_epoch_writes++;
1360 * If it was sent, it was the closing barrier for the last
1361 * replicated epoch, before we went into AHEAD mode.
1362 * No more barriers will be sent, until we leave AHEAD mode again. */
1363 maybe_send_barrier(connection, req->epoch);
1364
1365 err = drbd_send_out_of_sync(peer_device, req);
1366 req_mod(req, OOS_HANDED_TO_NETWORK);
1367
1368 return err;
1369}
1370
1371/**
1372 * w_send_dblock() - Worker callback to send a P_DATA packet in order to mirror a write request
1373 * @w: work object.
1374 * @cancel: The connection will be closed anyways
1375 */
1376int w_send_dblock(struct drbd_work *w, int cancel)
1377{
1378 struct drbd_request *req = container_of(w, struct drbd_request, w);
1379 struct drbd_device *device = req->device;
1380 struct drbd_peer_device *const peer_device = first_peer_device(device);
1381 struct drbd_connection *connection = peer_device->connection;
1382 int err;
1383
1384 if (unlikely(cancel)) {
1385 req_mod(req, SEND_CANCELED);
1386 return 0;
1387 }
1388 req->pre_send_jif = jiffies;
1389
1390 re_init_if_first_write(connection, req->epoch);
1391 maybe_send_barrier(connection, req->epoch);
1392 connection->send.current_epoch_writes++;
1393
1394 err = drbd_send_dblock(peer_device, req);
1395 req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK);
1396
1397 return err;
1398}
1399
1400/**
1401 * w_send_read_req() - Worker callback to send a read request (P_DATA_REQUEST) packet
1402 * @w: work object.
1403 * @cancel: The connection will be closed anyways
1404 */
1405int w_send_read_req(struct drbd_work *w, int cancel)
1406{
1407 struct drbd_request *req = container_of(w, struct drbd_request, w);
1408 struct drbd_device *device = req->device;
1409 struct drbd_peer_device *const peer_device = first_peer_device(device);
1410 struct drbd_connection *connection = peer_device->connection;
1411 int err;
1412
1413 if (unlikely(cancel)) {
1414 req_mod(req, SEND_CANCELED);
1415 return 0;
1416 }
1417 req->pre_send_jif = jiffies;
1418
1419 /* Even read requests may close a write epoch,
1420 * if there was any yet. */
1421 maybe_send_barrier(connection, req->epoch);
1422
1423 err = drbd_send_drequest(peer_device, P_DATA_REQUEST, req->i.sector, req->i.size,
1424 (unsigned long)req);
1425
1426 req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK);
1427
1428 return err;
1429}
1430
1431int w_restart_disk_io(struct drbd_work *w, int cancel)
1432{
1433 struct drbd_request *req = container_of(w, struct drbd_request, w);
1434 struct drbd_device *device = req->device;
1435
1436 if (bio_data_dir(req->master_bio) == WRITE && req->rq_state & RQ_IN_ACT_LOG)
1437 drbd_al_begin_io(device, &req->i);
1438
1439 drbd_req_make_private_bio(req, req->master_bio);
1440 req->private_bio->bi_bdev = device->ldev->backing_bdev;
1441 generic_make_request(req->private_bio);
1442
1443 return 0;
1444}
1445
1446static int _drbd_may_sync_now(struct drbd_device *device)
1447{
1448 struct drbd_device *odev = device;
1449 int resync_after;
1450
1451 while (1) {
1452 if (!odev->ldev || odev->state.disk == D_DISKLESS)
1453 return 1;
1454 rcu_read_lock();
1455 resync_after = rcu_dereference(odev->ldev->disk_conf)->resync_after;
1456 rcu_read_unlock();
1457 if (resync_after == -1)
1458 return 1;
1459 odev = minor_to_device(resync_after);
1460 if (!odev)
1461 return 1;
1462 if ((odev->state.conn >= C_SYNC_SOURCE &&
1463 odev->state.conn <= C_PAUSED_SYNC_T) ||
1464 odev->state.aftr_isp || odev->state.peer_isp ||
1465 odev->state.user_isp)
1466 return 0;
1467 }
1468}
1469
1470/**
1471 * drbd_pause_after() - Pause resync on all devices that may not resync now
1472 * @device: DRBD device.
1473 *
1474 * Called from process context only (admin command and after_state_ch).
1475 */
1476static bool drbd_pause_after(struct drbd_device *device)
1477{
1478 bool changed = false;
1479 struct drbd_device *odev;
1480 int i;
1481
1482 rcu_read_lock();
1483 idr_for_each_entry(&drbd_devices, odev, i) {
1484 if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
1485 continue;
1486 if (!_drbd_may_sync_now(odev) &&
1487 _drbd_set_state(_NS(odev, aftr_isp, 1),
1488 CS_HARD, NULL) != SS_NOTHING_TO_DO)
1489 changed = true;
1490 }
1491 rcu_read_unlock();
1492
1493 return changed;
1494}
1495
1496/**
1497 * drbd_resume_next() - Resume resync on all devices that may resync now
1498 * @device: DRBD device.
1499 *
1500 * Called from process context only (admin command and worker).
1501 */
1502static bool drbd_resume_next(struct drbd_device *device)
1503{
1504 bool changed = false;
1505 struct drbd_device *odev;
1506 int i;
1507
1508 rcu_read_lock();
1509 idr_for_each_entry(&drbd_devices, odev, i) {
1510 if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
1511 continue;
1512 if (odev->state.aftr_isp) {
1513 if (_drbd_may_sync_now(odev) &&
1514 _drbd_set_state(_NS(odev, aftr_isp, 0),
1515 CS_HARD, NULL) != SS_NOTHING_TO_DO)
1516 changed = true;
1517 }
1518 }
1519 rcu_read_unlock();
1520 return changed;
1521}
1522
1523void resume_next_sg(struct drbd_device *device)
1524{
1525 lock_all_resources();
1526 drbd_resume_next(device);
1527 unlock_all_resources();
1528}
1529
1530void suspend_other_sg(struct drbd_device *device)
1531{
1532 lock_all_resources();
1533 drbd_pause_after(device);
1534 unlock_all_resources();
1535}
1536
1537/* caller must lock_all_resources() */
1538enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor)
1539{
1540 struct drbd_device *odev;
1541 int resync_after;
1542
1543 if (o_minor == -1)
1544 return NO_ERROR;
1545 if (o_minor < -1 || o_minor > MINORMASK)
1546 return ERR_RESYNC_AFTER;
1547
1548 /* check for loops */
1549 odev = minor_to_device(o_minor);
1550 while (1) {
1551 if (odev == device)
1552 return ERR_RESYNC_AFTER_CYCLE;
1553
1554 /* You are free to depend on diskless, non-existing,
1555 * or not yet/no longer existing minors.
1556 * We only reject dependency loops.
1557 * We cannot follow the dependency chain beyond a detached or
1558 * missing minor.
1559 */
1560 if (!odev || !odev->ldev || odev->state.disk == D_DISKLESS)
1561 return NO_ERROR;
1562
1563 rcu_read_lock();
1564 resync_after = rcu_dereference(odev->ldev->disk_conf)->resync_after;
1565 rcu_read_unlock();
1566 /* dependency chain ends here, no cycles. */
1567 if (resync_after == -1)
1568 return NO_ERROR;
1569
1570 /* follow the dependency chain */
1571 odev = minor_to_device(resync_after);
1572 }
1573}
1574
1575/* caller must lock_all_resources() */
1576void drbd_resync_after_changed(struct drbd_device *device)
1577{
1578 int changed;
1579
1580 do {
1581 changed = drbd_pause_after(device);
1582 changed |= drbd_resume_next(device);
1583 } while (changed);
1584}
1585
1586void drbd_rs_controller_reset(struct drbd_device *device)
1587{
1588 struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk;
1589 struct fifo_buffer *plan;
1590
1591 atomic_set(&device->rs_sect_in, 0);
1592 atomic_set(&device->rs_sect_ev, 0);
1593 device->rs_in_flight = 0;
1594 device->rs_last_events =
1595 (int)part_stat_read(&disk->part0, sectors[0]) +
1596 (int)part_stat_read(&disk->part0, sectors[1]);
1597
1598 /* Updating the RCU protected object in place is necessary since
1599 this function gets called from atomic context.
1600 It is valid since all other updates also lead to an completely
1601 empty fifo */
1602 rcu_read_lock();
1603 plan = rcu_dereference(device->rs_plan_s);
1604 plan->total = 0;
1605 fifo_set(plan, 0);
1606 rcu_read_unlock();
1607}
1608
1609void start_resync_timer_fn(unsigned long data)
1610{
1611 struct drbd_device *device = (struct drbd_device *) data;
1612 drbd_device_post_work(device, RS_START);
1613}
1614
1615static void do_start_resync(struct drbd_device *device)
1616{
1617 if (atomic_read(&device->unacked_cnt) || atomic_read(&device->rs_pending_cnt)) {
1618 drbd_warn(device, "postponing start_resync ...\n");
1619 device->start_resync_timer.expires = jiffies + HZ/10;
1620 add_timer(&device->start_resync_timer);
1621 return;
1622 }
1623
1624 drbd_start_resync(device, C_SYNC_SOURCE);
1625 clear_bit(AHEAD_TO_SYNC_SOURCE, &device->flags);
1626}
1627
1628static bool use_checksum_based_resync(struct drbd_connection *connection, struct drbd_device *device)
1629{
1630 bool csums_after_crash_only;
1631 rcu_read_lock();
1632 csums_after_crash_only = rcu_dereference(connection->net_conf)->csums_after_crash_only;
1633 rcu_read_unlock();
1634 return connection->agreed_pro_version >= 89 && /* supported? */
1635 connection->csums_tfm && /* configured? */
1636 (csums_after_crash_only == 0 /* use for each resync? */
1637 || test_bit(CRASHED_PRIMARY, &device->flags)); /* or only after Primary crash? */
1638}
1639
1640/**
1641 * drbd_start_resync() - Start the resync process
1642 * @device: DRBD device.
1643 * @side: Either C_SYNC_SOURCE or C_SYNC_TARGET
1644 *
1645 * This function might bring you directly into one of the
1646 * C_PAUSED_SYNC_* states.
1647 */
1648void drbd_start_resync(struct drbd_device *device, enum drbd_conns side)
1649{
1650 struct drbd_peer_device *peer_device = first_peer_device(device);
1651 struct drbd_connection *connection = peer_device ? peer_device->connection : NULL;
1652 union drbd_state ns;
1653 int r;
1654
1655 if (device->state.conn >= C_SYNC_SOURCE && device->state.conn < C_AHEAD) {
1656 drbd_err(device, "Resync already running!\n");
1657 return;
1658 }
1659
1660 if (!test_bit(B_RS_H_DONE, &device->flags)) {
1661 if (side == C_SYNC_TARGET) {
1662 /* Since application IO was locked out during C_WF_BITMAP_T and
1663 C_WF_SYNC_UUID we are still unmodified. Before going to C_SYNC_TARGET
1664 we check that we might make the data inconsistent. */
1665 r = drbd_khelper(device, "before-resync-target");
1666 r = (r >> 8) & 0xff;
1667 if (r > 0) {
1668 drbd_info(device, "before-resync-target handler returned %d, "
1669 "dropping connection.\n", r);
1670 conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
1671 return;
1672 }
1673 } else /* C_SYNC_SOURCE */ {
1674 r = drbd_khelper(device, "before-resync-source");
1675 r = (r >> 8) & 0xff;
1676 if (r > 0) {
1677 if (r == 3) {
1678 drbd_info(device, "before-resync-source handler returned %d, "
1679 "ignoring. Old userland tools?", r);
1680 } else {
1681 drbd_info(device, "before-resync-source handler returned %d, "
1682 "dropping connection.\n", r);
1683 conn_request_state(connection,
1684 NS(conn, C_DISCONNECTING), CS_HARD);
1685 return;
1686 }
1687 }
1688 }
1689 }
1690
1691 if (current == connection->worker.task) {
1692 /* The worker should not sleep waiting for state_mutex,
1693 that can take long */
1694 if (!mutex_trylock(device->state_mutex)) {
1695 set_bit(B_RS_H_DONE, &device->flags);
1696 device->start_resync_timer.expires = jiffies + HZ/5;
1697 add_timer(&device->start_resync_timer);
1698 return;
1699 }
1700 } else {
1701 mutex_lock(device->state_mutex);
1702 }
1703
1704 lock_all_resources();
1705 clear_bit(B_RS_H_DONE, &device->flags);
1706 /* Did some connection breakage or IO error race with us? */
1707 if (device->state.conn < C_CONNECTED
1708 || !get_ldev_if_state(device, D_NEGOTIATING)) {
1709 unlock_all_resources();
1710 goto out;
1711 }
1712
1713 ns = drbd_read_state(device);
1714
1715 ns.aftr_isp = !_drbd_may_sync_now(device);
1716
1717 ns.conn = side;
1718
1719 if (side == C_SYNC_TARGET)
1720 ns.disk = D_INCONSISTENT;
1721 else /* side == C_SYNC_SOURCE */
1722 ns.pdsk = D_INCONSISTENT;
1723
1724 r = _drbd_set_state(device, ns, CS_VERBOSE, NULL);
1725 ns = drbd_read_state(device);
1726
1727 if (ns.conn < C_CONNECTED)
1728 r = SS_UNKNOWN_ERROR;
1729
1730 if (r == SS_SUCCESS) {
1731 unsigned long tw = drbd_bm_total_weight(device);
1732 unsigned long now = jiffies;
1733 int i;
1734
1735 device->rs_failed = 0;
1736 device->rs_paused = 0;
1737 device->rs_same_csum = 0;
1738 device->rs_last_sect_ev = 0;
1739 device->rs_total = tw;
1740 device->rs_start = now;
1741 for (i = 0; i < DRBD_SYNC_MARKS; i++) {
1742 device->rs_mark_left[i] = tw;
1743 device->rs_mark_time[i] = now;
1744 }
1745 drbd_pause_after(device);
1746 /* Forget potentially stale cached per resync extent bit-counts.
1747 * Open coded drbd_rs_cancel_all(device), we already have IRQs
1748 * disabled, and know the disk state is ok. */
1749 spin_lock(&device->al_lock);
1750 lc_reset(device->resync);
1751 device->resync_locked = 0;
1752 device->resync_wenr = LC_FREE;
1753 spin_unlock(&device->al_lock);
1754 }
1755 unlock_all_resources();
1756
1757 if (r == SS_SUCCESS) {
1758 wake_up(&device->al_wait); /* for lc_reset() above */
1759 /* reset rs_last_bcast when a resync or verify is started,
1760 * to deal with potential jiffies wrap. */
1761 device->rs_last_bcast = jiffies - HZ;
1762
1763 drbd_info(device, "Began resync as %s (will sync %lu KB [%lu bits set]).\n",
1764 drbd_conn_str(ns.conn),
1765 (unsigned long) device->rs_total << (BM_BLOCK_SHIFT-10),
1766 (unsigned long) device->rs_total);
1767 if (side == C_SYNC_TARGET) {
1768 device->bm_resync_fo = 0;
1769 device->use_csums = use_checksum_based_resync(connection, device);
1770 } else {
1771 device->use_csums = 0;
1772 }
1773
1774 /* Since protocol 96, we must serialize drbd_gen_and_send_sync_uuid
1775 * with w_send_oos, or the sync target will get confused as to
1776 * how much bits to resync. We cannot do that always, because for an
1777 * empty resync and protocol < 95, we need to do it here, as we call
1778 * drbd_resync_finished from here in that case.
1779 * We drbd_gen_and_send_sync_uuid here for protocol < 96,
1780 * and from after_state_ch otherwise. */
1781 if (side == C_SYNC_SOURCE && connection->agreed_pro_version < 96)
1782 drbd_gen_and_send_sync_uuid(peer_device);
1783
1784 if (connection->agreed_pro_version < 95 && device->rs_total == 0) {
1785 /* This still has a race (about when exactly the peers
1786 * detect connection loss) that can lead to a full sync
1787 * on next handshake. In 8.3.9 we fixed this with explicit
1788 * resync-finished notifications, but the fix
1789 * introduces a protocol change. Sleeping for some
1790 * time longer than the ping interval + timeout on the
1791 * SyncSource, to give the SyncTarget the chance to
1792 * detect connection loss, then waiting for a ping
1793 * response (implicit in drbd_resync_finished) reduces
1794 * the race considerably, but does not solve it. */
1795 if (side == C_SYNC_SOURCE) {
1796 struct net_conf *nc;
1797 int timeo;
1798
1799 rcu_read_lock();
1800 nc = rcu_dereference(connection->net_conf);
1801 timeo = nc->ping_int * HZ + nc->ping_timeo * HZ / 9;
1802 rcu_read_unlock();
1803 schedule_timeout_interruptible(timeo);
1804 }
1805 drbd_resync_finished(device);
1806 }
1807
1808 drbd_rs_controller_reset(device);
1809 /* ns.conn may already be != device->state.conn,
1810 * we may have been paused in between, or become paused until
1811 * the timer triggers.
1812 * No matter, that is handled in resync_timer_fn() */
1813 if (ns.conn == C_SYNC_TARGET)
1814 mod_timer(&device->resync_timer, jiffies);
1815
1816 drbd_md_sync(device);
1817 }
1818 put_ldev(device);
1819out:
1820 mutex_unlock(device->state_mutex);
1821}
1822
1823static void update_on_disk_bitmap(struct drbd_device *device, bool resync_done)
1824{
1825 struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, };
1826 device->rs_last_bcast = jiffies;
1827
1828 if (!get_ldev(device))
1829 return;
1830
1831 drbd_bm_write_lazy(device, 0);
1832 if (resync_done && is_sync_state(device->state.conn))
1833 drbd_resync_finished(device);
1834
1835 drbd_bcast_event(device, &sib);
1836 /* update timestamp, in case it took a while to write out stuff */
1837 device->rs_last_bcast = jiffies;
1838 put_ldev(device);
1839}
1840
1841static void drbd_ldev_destroy(struct drbd_device *device)
1842{
1843 lc_destroy(device->resync);
1844 device->resync = NULL;
1845 lc_destroy(device->act_log);
1846 device->act_log = NULL;
1847
1848 __acquire(local);
1849 drbd_backing_dev_free(device, device->ldev);
1850 device->ldev = NULL;
1851 __release(local);
1852
1853 clear_bit(GOING_DISKLESS, &device->flags);
1854 wake_up(&device->misc_wait);
1855}
1856
1857static void go_diskless(struct drbd_device *device)
1858{
1859 D_ASSERT(device, device->state.disk == D_FAILED);
1860 /* we cannot assert local_cnt == 0 here, as get_ldev_if_state will
1861 * inc/dec it frequently. Once we are D_DISKLESS, no one will touch
1862 * the protected members anymore, though, so once put_ldev reaches zero
1863 * again, it will be safe to free them. */
1864
1865 /* Try to write changed bitmap pages, read errors may have just
1866 * set some bits outside the area covered by the activity log.
1867 *
1868 * If we have an IO error during the bitmap writeout,
1869 * we will want a full sync next time, just in case.
1870 * (Do we want a specific meta data flag for this?)
1871 *
1872 * If that does not make it to stable storage either,
1873 * we cannot do anything about that anymore.
1874 *
1875 * We still need to check if both bitmap and ldev are present, we may
1876 * end up here after a failed attach, before ldev was even assigned.
1877 */
1878 if (device->bitmap && device->ldev) {
1879 /* An interrupted resync or similar is allowed to recounts bits
1880 * while we detach.
1881 * Any modifications would not be expected anymore, though.
1882 */
1883 if (drbd_bitmap_io_from_worker(device, drbd_bm_write,
1884 "detach", BM_LOCKED_TEST_ALLOWED)) {
1885 if (test_bit(WAS_READ_ERROR, &device->flags)) {
1886 drbd_md_set_flag(device, MDF_FULL_SYNC);
1887 drbd_md_sync(device);
1888 }
1889 }
1890 }
1891
1892 drbd_force_state(device, NS(disk, D_DISKLESS));
1893}
1894
1895static int do_md_sync(struct drbd_device *device)
1896{
1897 drbd_warn(device, "md_sync_timer expired! Worker calls drbd_md_sync().\n");
1898 drbd_md_sync(device);
1899 return 0;
1900}
1901
1902/* only called from drbd_worker thread, no locking */
1903void __update_timing_details(
1904 struct drbd_thread_timing_details *tdp,
1905 unsigned int *cb_nr,
1906 void *cb,
1907 const char *fn, const unsigned int line)
1908{
1909 unsigned int i = *cb_nr % DRBD_THREAD_DETAILS_HIST;
1910 struct drbd_thread_timing_details *td = tdp + i;
1911
1912 td->start_jif = jiffies;
1913 td->cb_addr = cb;
1914 td->caller_fn = fn;
1915 td->line = line;
1916 td->cb_nr = *cb_nr;
1917
1918 i = (i+1) % DRBD_THREAD_DETAILS_HIST;
1919 td = tdp + i;
1920 memset(td, 0, sizeof(*td));
1921
1922 ++(*cb_nr);
1923}
1924
1925static void do_device_work(struct drbd_device *device, const unsigned long todo)
1926{
1927 if (test_bit(MD_SYNC, &todo))
1928 do_md_sync(device);
1929 if (test_bit(RS_DONE, &todo) ||
1930 test_bit(RS_PROGRESS, &todo))
1931 update_on_disk_bitmap(device, test_bit(RS_DONE, &todo));
1932 if (test_bit(GO_DISKLESS, &todo))
1933 go_diskless(device);
1934 if (test_bit(DESTROY_DISK, &todo))
1935 drbd_ldev_destroy(device);
1936 if (test_bit(RS_START, &todo))
1937 do_start_resync(device);
1938}
1939
1940#define DRBD_DEVICE_WORK_MASK \
1941 ((1UL << GO_DISKLESS) \
1942 |(1UL << DESTROY_DISK) \
1943 |(1UL << MD_SYNC) \
1944 |(1UL << RS_START) \
1945 |(1UL << RS_PROGRESS) \
1946 |(1UL << RS_DONE) \
1947 )
1948
1949static unsigned long get_work_bits(unsigned long *flags)
1950{
1951 unsigned long old, new;
1952 do {
1953 old = *flags;
1954 new = old & ~DRBD_DEVICE_WORK_MASK;
1955 } while (cmpxchg(flags, old, new) != old);
1956 return old & DRBD_DEVICE_WORK_MASK;
1957}
1958
1959static void do_unqueued_work(struct drbd_connection *connection)
1960{
1961 struct drbd_peer_device *peer_device;
1962 int vnr;
1963
1964 rcu_read_lock();
1965 idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
1966 struct drbd_device *device = peer_device->device;
1967 unsigned long todo = get_work_bits(&device->flags);
1968 if (!todo)
1969 continue;
1970
1971 kref_get(&device->kref);
1972 rcu_read_unlock();
1973 do_device_work(device, todo);
1974 kref_put(&device->kref, drbd_destroy_device);
1975 rcu_read_lock();
1976 }
1977 rcu_read_unlock();
1978}
1979
1980static bool dequeue_work_batch(struct drbd_work_queue *queue, struct list_head *work_list)
1981{
1982 spin_lock_irq(&queue->q_lock);
1983 list_splice_tail_init(&queue->q, work_list);
1984 spin_unlock_irq(&queue->q_lock);
1985 return !list_empty(work_list);
1986}
1987
1988static void wait_for_work(struct drbd_connection *connection, struct list_head *work_list)
1989{
1990 DEFINE_WAIT(wait);
1991 struct net_conf *nc;
1992 int uncork, cork;
1993
1994 dequeue_work_batch(&connection->sender_work, work_list);
1995 if (!list_empty(work_list))
1996 return;
1997
1998 /* Still nothing to do?
1999 * Maybe we still need to close the current epoch,
2000 * even if no new requests are queued yet.
2001 *
2002 * Also, poke TCP, just in case.
2003 * Then wait for new work (or signal). */
2004 rcu_read_lock();
2005 nc = rcu_dereference(connection->net_conf);
2006 uncork = nc ? nc->tcp_cork : 0;
2007 rcu_read_unlock();
2008 if (uncork) {
2009 mutex_lock(&connection->data.mutex);
2010 if (connection->data.socket)
2011 drbd_tcp_uncork(connection->data.socket);
2012 mutex_unlock(&connection->data.mutex);
2013 }
2014
2015 for (;;) {
2016 int send_barrier;
2017 prepare_to_wait(&connection->sender_work.q_wait, &wait, TASK_INTERRUPTIBLE);
2018 spin_lock_irq(&connection->resource->req_lock);
2019 spin_lock(&connection->sender_work.q_lock); /* FIXME get rid of this one? */
2020 if (!list_empty(&connection->sender_work.q))
2021 list_splice_tail_init(&connection->sender_work.q, work_list);
2022 spin_unlock(&connection->sender_work.q_lock); /* FIXME get rid of this one? */
2023 if (!list_empty(work_list) || signal_pending(current)) {
2024 spin_unlock_irq(&connection->resource->req_lock);
2025 break;
2026 }
2027
2028 /* We found nothing new to do, no to-be-communicated request,
2029 * no other work item. We may still need to close the last
2030 * epoch. Next incoming request epoch will be connection ->
2031 * current transfer log epoch number. If that is different
2032 * from the epoch of the last request we communicated, it is
2033 * safe to send the epoch separating barrier now.
2034 */
2035 send_barrier =
2036 atomic_read(&connection->current_tle_nr) !=
2037 connection->send.current_epoch_nr;
2038 spin_unlock_irq(&connection->resource->req_lock);
2039
2040 if (send_barrier)
2041 maybe_send_barrier(connection,
2042 connection->send.current_epoch_nr + 1);
2043
2044 if (test_bit(DEVICE_WORK_PENDING, &connection->flags))
2045 break;
2046
2047 /* drbd_send() may have called flush_signals() */
2048 if (get_t_state(&connection->worker) != RUNNING)
2049 break;
2050
2051 schedule();
2052 /* may be woken up for other things but new work, too,
2053 * e.g. if the current epoch got closed.
2054 * In which case we send the barrier above. */
2055 }
2056 finish_wait(&connection->sender_work.q_wait, &wait);
2057
2058 /* someone may have changed the config while we have been waiting above. */
2059 rcu_read_lock();
2060 nc = rcu_dereference(connection->net_conf);
2061 cork = nc ? nc->tcp_cork : 0;
2062 rcu_read_unlock();
2063 mutex_lock(&connection->data.mutex);
2064 if (connection->data.socket) {
2065 if (cork)
2066 drbd_tcp_cork(connection->data.socket);
2067 else if (!uncork)
2068 drbd_tcp_uncork(connection->data.socket);
2069 }
2070 mutex_unlock(&connection->data.mutex);
2071}
2072
2073int drbd_worker(struct drbd_thread *thi)
2074{
2075 struct drbd_connection *connection = thi->connection;
2076 struct drbd_work *w = NULL;
2077 struct drbd_peer_device *peer_device;
2078 LIST_HEAD(work_list);
2079 int vnr;
2080
2081 while (get_t_state(thi) == RUNNING) {
2082 drbd_thread_current_set_cpu(thi);
2083
2084 if (list_empty(&work_list)) {
2085 update_worker_timing_details(connection, wait_for_work);
2086 wait_for_work(connection, &work_list);
2087 }
2088
2089 if (test_and_clear_bit(DEVICE_WORK_PENDING, &connection->flags)) {
2090 update_worker_timing_details(connection, do_unqueued_work);
2091 do_unqueued_work(connection);
2092 }
2093
2094 if (signal_pending(current)) {
2095 flush_signals(current);
2096 if (get_t_state(thi) == RUNNING) {
2097 drbd_warn(connection, "Worker got an unexpected signal\n");
2098 continue;
2099 }
2100 break;
2101 }
2102
2103 if (get_t_state(thi) != RUNNING)
2104 break;
2105
2106 if (!list_empty(&work_list)) {
2107 w = list_first_entry(&work_list, struct drbd_work, list);
2108 list_del_init(&w->list);
2109 update_worker_timing_details(connection, w->cb);
2110 if (w->cb(w, connection->cstate < C_WF_REPORT_PARAMS) == 0)
2111 continue;
2112 if (connection->cstate >= C_WF_REPORT_PARAMS)
2113 conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD);
2114 }
2115 }
2116
2117 do {
2118 if (test_and_clear_bit(DEVICE_WORK_PENDING, &connection->flags)) {
2119 update_worker_timing_details(connection, do_unqueued_work);
2120 do_unqueued_work(connection);
2121 }
2122 if (!list_empty(&work_list)) {
2123 w = list_first_entry(&work_list, struct drbd_work, list);
2124 list_del_init(&w->list);
2125 update_worker_timing_details(connection, w->cb);
2126 w->cb(w, 1);
2127 } else
2128 dequeue_work_batch(&connection->sender_work, &work_list);
2129 } while (!list_empty(&work_list) || test_bit(DEVICE_WORK_PENDING, &connection->flags));
2130
2131 rcu_read_lock();
2132 idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2133 struct drbd_device *device = peer_device->device;
2134 D_ASSERT(device, device->state.disk == D_DISKLESS && device->state.conn == C_STANDALONE);
2135 kref_get(&device->kref);
2136 rcu_read_unlock();
2137 drbd_device_cleanup(device);
2138 kref_put(&device->kref, drbd_destroy_device);
2139 rcu_read_lock();
2140 }
2141 rcu_read_unlock();
2142
2143 return 0;
2144}