4 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
6 Copyright (C) 2003-2008, LINBIT Information Technologies GmbH.
7 Copyright (C) 2003-2008, Philipp Reisner <philipp.reisner@linbit.com>.
8 Copyright (C) 2003-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
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)
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.
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.
26 #include <linux/slab.h>
27 #include <linux/crc32c.h>
28 #include <linux/drbd.h>
29 #include <linux/drbd_limits.h>
30 #include <linux/dynamic_debug.h>
32 #include "drbd_wrappers.h"
35 enum al_transaction_types {
37 AL_TR_INITIALIZED = 0xffff
39 /* all fields on disc in big endian */
40 struct __packed al_transaction_on_disk {
41 /* don't we all like magic */
44 /* to identify the most recent transaction block
45 * in the on disk ring buffer */
48 /* checksum on the full 4k block, with this field set to 0. */
51 /* type of transaction, special transaction types like:
52 * purge-all, set-all-idle, set-all-active, ... to-be-defined
53 * see also enum al_transaction_types */
54 __be16 transaction_type;
56 /* we currently allow only a few thousand extents,
57 * so 16bit will be enough for the slot number. */
59 /* how many updates in this transaction */
62 /* maximum slot number, "al-extents" in drbd.conf speak.
63 * Having this in each transaction should make reconfiguration
64 * of that parameter easier. */
67 /* slot number the context starts with */
68 __be16 context_start_slot_nr;
70 /* Some reserved bytes. Expected usage is a 64bit counter of
71 * sectors-written since device creation, and other data generation tag
75 /* --- 36 byte used --- */
77 /* Reserve space for up to AL_UPDATES_PER_TRANSACTION changes
78 * in one transaction, then use the remaining byte in the 4k block for
79 * context information. "Flexible" number of updates per transaction
80 * does not help, as we have to account for the case when all update
81 * slots are used anyways, so it would only complicate code without
84 __be16 update_slot_nr[AL_UPDATES_PER_TRANSACTION];
86 /* but the extent number is 32bit, which at an extent size of 4 MiB
87 * allows to cover device sizes of up to 2**54 Byte (16 PiB) */
88 __be32 update_extent_nr[AL_UPDATES_PER_TRANSACTION];
90 /* --- 420 bytes used (36 + 64*6) --- */
92 /* 4096 - 420 = 3676 = 919 * 4 */
93 __be32 context[AL_CONTEXT_PER_TRANSACTION];
96 struct update_odbm_work {
98 struct drbd_device *device;
102 struct update_al_work {
104 struct drbd_device *device;
105 struct completion event;
110 void *drbd_md_get_buffer(struct drbd_device *device)
114 wait_event(device->misc_wait,
115 (r = atomic_cmpxchg(&device->md_io_in_use, 0, 1)) == 0 ||
116 device->state.disk <= D_FAILED);
118 return r ? NULL : page_address(device->md_io_page);
121 void drbd_md_put_buffer(struct drbd_device *device)
123 if (atomic_dec_and_test(&device->md_io_in_use))
124 wake_up(&device->misc_wait);
127 void wait_until_done_or_force_detached(struct drbd_device *device, struct drbd_backing_dev *bdev,
133 dt = rcu_dereference(bdev->disk_conf)->disk_timeout;
137 dt = MAX_SCHEDULE_TIMEOUT;
139 dt = wait_event_timeout(device->misc_wait,
140 *done || test_bit(FORCE_DETACH, &device->flags), dt);
142 drbd_err(device, "meta-data IO operation timed out\n");
143 drbd_chk_io_error(device, 1, DRBD_FORCE_DETACH);
147 static int _drbd_md_sync_page_io(struct drbd_device *device,
148 struct drbd_backing_dev *bdev,
149 struct page *page, sector_t sector,
155 device->md_io.done = 0;
156 device->md_io.error = -ENODEV;
158 if ((rw & WRITE) && !test_bit(MD_NO_FUA, &device->flags))
159 rw |= REQ_FUA | REQ_FLUSH;
162 bio = bio_alloc_drbd(GFP_NOIO);
163 bio->bi_bdev = bdev->md_bdev;
164 bio->bi_iter.bi_sector = sector;
166 if (bio_add_page(bio, page, size, 0) != size)
168 bio->bi_private = &device->md_io;
169 bio->bi_end_io = drbd_md_io_complete;
172 if (!(rw & WRITE) && device->state.disk == D_DISKLESS && device->ldev == NULL)
173 /* special case, drbd_md_read() during drbd_adm_attach(): no get_ldev */
175 else if (!get_ldev_if_state(device, D_ATTACHING)) {
176 /* Corresponding put_ldev in drbd_md_io_complete() */
177 drbd_err(device, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n");
182 bio_get(bio); /* one bio_put() is in the completion handler */
183 atomic_inc(&device->md_io_in_use); /* drbd_md_put_buffer() is in the completion handler */
184 if (drbd_insert_fault(device, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD))
185 bio_endio(bio, -EIO);
188 wait_until_done_or_force_detached(device, bdev, &device->md_io.done);
189 if (bio_flagged(bio, BIO_UPTODATE))
190 err = device->md_io.error;
197 int drbd_md_sync_page_io(struct drbd_device *device, struct drbd_backing_dev *bdev,
198 sector_t sector, int rw)
201 struct page *iop = device->md_io_page;
203 D_ASSERT(device, atomic_read(&device->md_io_in_use) == 1);
205 BUG_ON(!bdev->md_bdev);
207 drbd_dbg(device, "meta_data io: %s [%d]:%s(,%llus,%s) %pS\n",
208 current->comm, current->pid, __func__,
209 (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ",
212 if (sector < drbd_md_first_sector(bdev) ||
213 sector + 7 > drbd_md_last_sector(bdev))
214 drbd_alert(device, "%s [%d]:%s(,%llus,%s) out of range md access!\n",
215 current->comm, current->pid, __func__,
216 (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
218 /* we do all our meta data IO in aligned 4k blocks. */
219 err = _drbd_md_sync_page_io(device, bdev, iop, sector, rw, 4096);
221 drbd_err(device, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n",
222 (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ", err);
227 static struct bm_extent *find_active_resync_extent(struct drbd_device *device, unsigned int enr)
229 struct lc_element *tmp;
230 tmp = lc_find(device->resync, enr/AL_EXT_PER_BM_SECT);
231 if (unlikely(tmp != NULL)) {
232 struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
233 if (test_bit(BME_NO_WRITES, &bm_ext->flags))
239 static struct lc_element *_al_get(struct drbd_device *device, unsigned int enr, bool nonblock)
241 struct lc_element *al_ext;
242 struct bm_extent *bm_ext;
245 spin_lock_irq(&device->al_lock);
246 bm_ext = find_active_resync_extent(device, enr);
248 wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags);
249 spin_unlock_irq(&device->al_lock);
251 wake_up(&device->al_wait);
255 al_ext = lc_try_get(device->act_log, enr);
257 al_ext = lc_get(device->act_log, enr);
258 spin_unlock_irq(&device->al_lock);
262 bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i)
264 /* for bios crossing activity log extent boundaries,
265 * we may need to activate two extents in one go */
266 unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
267 unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
269 D_ASSERT(device, (unsigned)(last - first) <= 1);
270 D_ASSERT(device, atomic_read(&device->local_cnt) > 0);
272 /* FIXME figure out a fast path for bios crossing AL extent boundaries */
276 return _al_get(device, first, true);
280 bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i)
282 /* for bios crossing activity log extent boundaries,
283 * we may need to activate two extents in one go */
284 unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
285 unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
287 bool need_transaction = false;
289 D_ASSERT(device, first <= last);
290 D_ASSERT(device, atomic_read(&device->local_cnt) > 0);
292 for (enr = first; enr <= last; enr++) {
293 struct lc_element *al_ext;
294 wait_event(device->al_wait,
295 (al_ext = _al_get(device, enr, false)) != NULL);
296 if (al_ext->lc_number != enr)
297 need_transaction = true;
299 return need_transaction;
302 static int al_write_transaction(struct drbd_device *device, bool delegate);
304 /* When called through generic_make_request(), we must delegate
305 * activity log I/O to the worker thread: a further request
306 * submitted via generic_make_request() within the same task
307 * would be queued on current->bio_list, and would only start
308 * after this function returns (see generic_make_request()).
310 * However, if we *are* the worker, we must not delegate to ourselves.
314 * @delegate: delegate activity log I/O to the worker thread
316 void drbd_al_begin_io_commit(struct drbd_device *device, bool delegate)
320 BUG_ON(delegate && current == first_peer_device(device)->connection->worker.task);
322 /* Serialize multiple transactions.
323 * This uses test_and_set_bit, memory barrier is implicit.
325 wait_event(device->al_wait,
326 device->act_log->pending_changes == 0 ||
327 (locked = lc_try_lock_for_transaction(device->act_log)));
330 /* Double check: it may have been committed by someone else,
331 * while we have been waiting for the lock. */
332 if (device->act_log->pending_changes) {
333 bool write_al_updates;
336 write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates;
339 if (write_al_updates)
340 al_write_transaction(device, delegate);
341 spin_lock_irq(&device->al_lock);
344 we need an "lc_cancel" here;
346 lc_committed(device->act_log);
347 spin_unlock_irq(&device->al_lock);
349 lc_unlock(device->act_log);
350 wake_up(&device->al_wait);
355 * @delegate: delegate activity log I/O to the worker thread
357 void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i, bool delegate)
359 BUG_ON(delegate && current == first_peer_device(device)->connection->worker.task);
361 if (drbd_al_begin_io_prepare(device, i))
362 drbd_al_begin_io_commit(device, delegate);
365 int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i)
367 struct lru_cache *al = device->act_log;
368 /* for bios crossing activity log extent boundaries,
369 * we may need to activate two extents in one go */
370 unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
371 unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
372 unsigned nr_al_extents;
373 unsigned available_update_slots;
376 D_ASSERT(device, first <= last);
378 nr_al_extents = 1 + last - first; /* worst case: all touched extends are cold. */
379 available_update_slots = min(al->nr_elements - al->used,
380 al->max_pending_changes - al->pending_changes);
382 /* We want all necessary updates for a given request within the same transaction
383 * We could first check how many updates are *actually* needed,
384 * and use that instead of the worst-case nr_al_extents */
385 if (available_update_slots < nr_al_extents)
388 /* Is resync active in this area? */
389 for (enr = first; enr <= last; enr++) {
390 struct lc_element *tmp;
391 tmp = lc_find(device->resync, enr/AL_EXT_PER_BM_SECT);
392 if (unlikely(tmp != NULL)) {
393 struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
394 if (test_bit(BME_NO_WRITES, &bm_ext->flags)) {
395 if (!test_and_set_bit(BME_PRIORITY, &bm_ext->flags))
402 /* Checkout the refcounts.
403 * Given that we checked for available elements and update slots above,
404 * this has to be successful. */
405 for (enr = first; enr <= last; enr++) {
406 struct lc_element *al_ext;
407 al_ext = lc_get_cumulative(device->act_log, enr);
409 drbd_info(device, "LOGIC BUG for enr=%u\n", enr);
414 void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i)
416 /* for bios crossing activity log extent boundaries,
417 * we may need to activate two extents in one go */
418 unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
419 unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
421 struct lc_element *extent;
424 D_ASSERT(device, first <= last);
425 spin_lock_irqsave(&device->al_lock, flags);
427 for (enr = first; enr <= last; enr++) {
428 extent = lc_find(device->act_log, enr);
430 drbd_err(device, "al_complete_io() called on inactive extent %u\n", enr);
433 lc_put(device->act_log, extent);
435 spin_unlock_irqrestore(&device->al_lock, flags);
436 wake_up(&device->al_wait);
439 #if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)
440 /* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT
441 * are still coupled, or assume too much about their relation.
442 * Code below will not work if this is violated.
443 * Will be cleaned up with some followup patch.
448 static unsigned int al_extent_to_bm_page(unsigned int al_enr)
453 /* al extent number to bit */
454 (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT));
457 static unsigned int rs_extent_to_bm_page(unsigned int rs_enr)
462 /* resync extent number to bit */
463 (BM_EXT_SHIFT - BM_BLOCK_SHIFT));
466 static sector_t al_tr_number_to_on_disk_sector(struct drbd_device *device)
468 const unsigned int stripes = device->ldev->md.al_stripes;
469 const unsigned int stripe_size_4kB = device->ldev->md.al_stripe_size_4k;
471 /* transaction number, modulo on-disk ring buffer wrap around */
472 unsigned int t = device->al_tr_number % (device->ldev->md.al_size_4k);
474 /* ... to aligned 4k on disk block */
475 t = ((t % stripes) * stripe_size_4kB) + t/stripes;
477 /* ... to 512 byte sector in activity log */
480 /* ... plus offset to the on disk position */
481 return device->ldev->md.md_offset + device->ldev->md.al_offset + t;
485 _al_write_transaction(struct drbd_device *device)
487 struct al_transaction_on_disk *buffer;
488 struct lc_element *e;
495 if (!get_ldev(device)) {
496 drbd_err(device, "disk is %s, cannot start al transaction\n",
497 drbd_disk_str(device->state.disk));
501 /* The bitmap write may have failed, causing a state change. */
502 if (device->state.disk < D_INCONSISTENT) {
504 "disk is %s, cannot write al transaction\n",
505 drbd_disk_str(device->state.disk));
510 buffer = drbd_md_get_buffer(device); /* protects md_io_buffer, al_tr_cycle, ... */
512 drbd_err(device, "disk failed while waiting for md_io buffer\n");
517 memset(buffer, 0, sizeof(*buffer));
518 buffer->magic = cpu_to_be32(DRBD_AL_MAGIC);
519 buffer->tr_number = cpu_to_be32(device->al_tr_number);
523 /* Even though no one can start to change this list
524 * once we set the LC_LOCKED -- from drbd_al_begin_io(),
525 * lc_try_lock_for_transaction() --, someone may still
526 * be in the process of changing it. */
527 spin_lock_irq(&device->al_lock);
528 list_for_each_entry(e, &device->act_log->to_be_changed, list) {
529 if (i == AL_UPDATES_PER_TRANSACTION) {
533 buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index);
534 buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number);
535 if (e->lc_number != LC_FREE)
536 drbd_bm_mark_for_writeout(device,
537 al_extent_to_bm_page(e->lc_number));
540 spin_unlock_irq(&device->al_lock);
541 BUG_ON(i > AL_UPDATES_PER_TRANSACTION);
543 buffer->n_updates = cpu_to_be16(i);
544 for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) {
545 buffer->update_slot_nr[i] = cpu_to_be16(-1);
546 buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE);
549 buffer->context_size = cpu_to_be16(device->act_log->nr_elements);
550 buffer->context_start_slot_nr = cpu_to_be16(device->al_tr_cycle);
552 mx = min_t(int, AL_CONTEXT_PER_TRANSACTION,
553 device->act_log->nr_elements - device->al_tr_cycle);
554 for (i = 0; i < mx; i++) {
555 unsigned idx = device->al_tr_cycle + i;
556 extent_nr = lc_element_by_index(device->act_log, idx)->lc_number;
557 buffer->context[i] = cpu_to_be32(extent_nr);
559 for (; i < AL_CONTEXT_PER_TRANSACTION; i++)
560 buffer->context[i] = cpu_to_be32(LC_FREE);
562 device->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION;
563 if (device->al_tr_cycle >= device->act_log->nr_elements)
564 device->al_tr_cycle = 0;
566 sector = al_tr_number_to_on_disk_sector(device);
568 crc = crc32c(0, buffer, 4096);
569 buffer->crc32c = cpu_to_be32(crc);
571 if (drbd_bm_write_hinted(device))
574 bool write_al_updates;
576 write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates;
578 if (write_al_updates) {
579 if (drbd_md_sync_page_io(device, device->ldev, sector, WRITE)) {
581 drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR);
583 device->al_tr_number++;
584 device->al_writ_cnt++;
589 drbd_md_put_buffer(device);
596 static int w_al_write_transaction(struct drbd_work *w, int unused)
598 struct update_al_work *aw = container_of(w, struct update_al_work, w);
599 struct drbd_device *device = aw->device;
602 err = _al_write_transaction(device);
604 complete(&aw->event);
606 return err != -EIO ? err : 0;
609 /* Calls from worker context (see w_restart_disk_io()) need to write the
610 transaction directly. Others came through generic_make_request(),
611 those need to delegate it to the worker. */
612 static int al_write_transaction(struct drbd_device *device, bool delegate)
615 struct update_al_work al_work;
616 init_completion(&al_work.event);
617 al_work.w.cb = w_al_write_transaction;
618 al_work.device = device;
619 drbd_queue_work_front(&first_peer_device(device)->connection->sender_work,
621 wait_for_completion(&al_work.event);
624 return _al_write_transaction(device);
627 static int _try_lc_del(struct drbd_device *device, struct lc_element *al_ext)
631 spin_lock_irq(&device->al_lock);
632 rv = (al_ext->refcnt == 0);
634 lc_del(device->act_log, al_ext);
635 spin_unlock_irq(&device->al_lock);
641 * drbd_al_shrink() - Removes all active extents form the activity log
642 * @device: DRBD device.
644 * Removes all active extents form the activity log, waiting until
645 * the reference count of each entry dropped to 0 first, of course.
647 * You need to lock device->act_log with lc_try_lock() / lc_unlock()
649 void drbd_al_shrink(struct drbd_device *device)
651 struct lc_element *al_ext;
654 D_ASSERT(device, test_bit(__LC_LOCKED, &device->act_log->flags));
656 for (i = 0; i < device->act_log->nr_elements; i++) {
657 al_ext = lc_element_by_index(device->act_log, i);
658 if (al_ext->lc_number == LC_FREE)
660 wait_event(device->al_wait, _try_lc_del(device, al_ext));
663 wake_up(&device->al_wait);
666 int drbd_initialize_al(struct drbd_device *device, void *buffer)
668 struct al_transaction_on_disk *al = buffer;
669 struct drbd_md *md = &device->ldev->md;
670 sector_t al_base = md->md_offset + md->al_offset;
671 int al_size_4k = md->al_stripes * md->al_stripe_size_4k;
675 al->magic = cpu_to_be32(DRBD_AL_MAGIC);
676 al->transaction_type = cpu_to_be16(AL_TR_INITIALIZED);
677 al->crc32c = cpu_to_be32(crc32c(0, al, 4096));
679 for (i = 0; i < al_size_4k; i++) {
680 int err = drbd_md_sync_page_io(device, device->ldev, al_base + i * 8, WRITE);
687 static int w_update_odbm(struct drbd_work *w, int unused)
689 struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w);
690 struct drbd_device *device = udw->device;
691 struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, };
693 if (!get_ldev(device)) {
694 if (__ratelimit(&drbd_ratelimit_state))
695 drbd_warn(device, "Can not update on disk bitmap, local IO disabled.\n");
700 drbd_bm_write_page(device, rs_extent_to_bm_page(udw->enr));
705 if (drbd_bm_total_weight(device) <= device->rs_failed) {
706 switch (device->state.conn) {
707 case C_SYNC_SOURCE: case C_SYNC_TARGET:
708 case C_PAUSED_SYNC_S: case C_PAUSED_SYNC_T:
709 drbd_resync_finished(device);
715 drbd_bcast_event(device, &sib);
721 /* ATTENTION. The AL's extents are 4MB each, while the extents in the
722 * resync LRU-cache are 16MB each.
723 * The caller of this function has to hold an get_ldev() reference.
725 * TODO will be obsoleted once we have a caching lru of the on disk bitmap
727 static void drbd_try_clear_on_disk_bm(struct drbd_device *device, sector_t sector,
728 int count, int success)
730 struct lc_element *e;
731 struct update_odbm_work *udw;
735 D_ASSERT(device, atomic_read(&device->local_cnt));
737 /* I simply assume that a sector/size pair never crosses
738 * a 16 MB extent border. (Currently this is true...) */
739 enr = BM_SECT_TO_EXT(sector);
741 e = lc_get(device->resync, enr);
743 struct bm_extent *ext = lc_entry(e, struct bm_extent, lce);
744 if (ext->lce.lc_number == enr) {
746 ext->rs_left -= count;
748 ext->rs_failed += count;
749 if (ext->rs_left < ext->rs_failed) {
750 drbd_warn(device, "BAD! sector=%llus enr=%u rs_left=%d "
751 "rs_failed=%d count=%d cstate=%s\n",
752 (unsigned long long)sector,
753 ext->lce.lc_number, ext->rs_left,
754 ext->rs_failed, count,
755 drbd_conn_str(device->state.conn));
757 /* We don't expect to be able to clear more bits
758 * than have been set when we originally counted
759 * the set bits to cache that value in ext->rs_left.
760 * Whatever the reason (disconnect during resync,
761 * delayed local completion of an application write),
762 * try to fix it up by recounting here. */
763 ext->rs_left = drbd_bm_e_weight(device, enr);
766 /* Normally this element should be in the cache,
767 * since drbd_rs_begin_io() pulled it already in.
769 * But maybe an application write finished, and we set
770 * something outside the resync lru_cache in sync.
772 int rs_left = drbd_bm_e_weight(device, enr);
773 if (ext->flags != 0) {
774 drbd_warn(device, "changing resync lce: %d[%u;%02lx]"
776 ext->lce.lc_number, ext->rs_left,
777 ext->flags, enr, rs_left);
780 if (ext->rs_failed) {
781 drbd_warn(device, "Kicking resync_lru element enr=%u "
782 "out with rs_failed=%d\n",
783 ext->lce.lc_number, ext->rs_failed);
785 ext->rs_left = rs_left;
786 ext->rs_failed = success ? 0 : count;
787 /* we don't keep a persistent log of the resync lru,
788 * we can commit any change right away. */
789 lc_committed(device->resync);
791 lc_put(device->resync, &ext->lce);
792 /* no race, we are within the al_lock! */
794 if (ext->rs_left == ext->rs_failed) {
797 udw = kmalloc(sizeof(*udw), GFP_ATOMIC);
799 udw->enr = ext->lce.lc_number;
800 udw->w.cb = w_update_odbm;
801 udw->device = device;
802 drbd_queue_work_front(&first_peer_device(device)->connection->sender_work,
805 drbd_warn(device, "Could not kmalloc an udw\n");
809 drbd_err(device, "lc_get() failed! locked=%d/%d flags=%lu\n",
810 device->resync_locked,
811 device->resync->nr_elements,
812 device->resync->flags);
816 void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go)
818 unsigned long now = jiffies;
819 unsigned long last = device->rs_mark_time[device->rs_last_mark];
820 int next = (device->rs_last_mark + 1) % DRBD_SYNC_MARKS;
821 if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) {
822 if (device->rs_mark_left[device->rs_last_mark] != still_to_go &&
823 device->state.conn != C_PAUSED_SYNC_T &&
824 device->state.conn != C_PAUSED_SYNC_S) {
825 device->rs_mark_time[next] = now;
826 device->rs_mark_left[next] = still_to_go;
827 device->rs_last_mark = next;
832 /* clear the bit corresponding to the piece of storage in question:
833 * size byte of data starting from sector. Only clear a bits of the affected
834 * one ore more _aligned_ BM_BLOCK_SIZE blocks.
836 * called by worker on C_SYNC_TARGET and receiver on SyncSource.
839 void __drbd_set_in_sync(struct drbd_device *device, sector_t sector, int size,
840 const char *file, const unsigned int line)
842 /* Is called from worker and receiver context _only_ */
843 unsigned long sbnr, ebnr, lbnr;
844 unsigned long count = 0;
845 sector_t esector, nr_sectors;
849 if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
850 drbd_err(device, "drbd_set_in_sync: sector=%llus size=%d nonsense!\n",
851 (unsigned long long)sector, size);
855 if (!get_ldev(device))
856 return; /* no disk, no metadata, no bitmap to clear bits in */
858 nr_sectors = drbd_get_capacity(device->this_bdev);
859 esector = sector + (size >> 9) - 1;
861 if (!expect(sector < nr_sectors))
863 if (!expect(esector < nr_sectors))
864 esector = nr_sectors - 1;
866 lbnr = BM_SECT_TO_BIT(nr_sectors-1);
868 /* we clear it (in sync).
869 * round up start sector, round down end sector. we make sure we only
870 * clear full, aligned, BM_BLOCK_SIZE (4K) blocks */
871 if (unlikely(esector < BM_SECT_PER_BIT-1))
873 if (unlikely(esector == (nr_sectors-1)))
876 ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1));
877 sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1);
883 * ok, (capacity & 7) != 0 sometimes, but who cares...
884 * we count rs_{total,left} in bits, not sectors.
886 count = drbd_bm_clear_bits(device, sbnr, ebnr);
888 drbd_advance_rs_marks(device, drbd_bm_total_weight(device));
889 spin_lock_irqsave(&device->al_lock, flags);
890 drbd_try_clear_on_disk_bm(device, sector, count, true);
891 spin_unlock_irqrestore(&device->al_lock, flags);
893 /* just wake_up unconditional now, various lc_chaged(),
894 * lc_put() in drbd_try_clear_on_disk_bm(). */
900 wake_up(&device->al_wait);
904 * this is intended to set one request worth of data out of sync.
905 * affects at least 1 bit,
906 * and at most 1+DRBD_MAX_BIO_SIZE/BM_BLOCK_SIZE bits.
908 * called by tl_clear and drbd_send_dblock (==drbd_make_request).
909 * so this can be _any_ process.
911 int __drbd_set_out_of_sync(struct drbd_device *device, sector_t sector, int size,
912 const char *file, const unsigned int line)
914 unsigned long sbnr, ebnr, flags;
915 sector_t esector, nr_sectors;
916 unsigned int enr, count = 0;
917 struct lc_element *e;
919 /* this should be an empty REQ_FLUSH */
923 if (size < 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
924 drbd_err(device, "sector: %llus, size: %d\n",
925 (unsigned long long)sector, size);
929 if (!get_ldev(device))
930 return 0; /* no disk, no metadata, no bitmap to set bits in */
932 nr_sectors = drbd_get_capacity(device->this_bdev);
933 esector = sector + (size >> 9) - 1;
935 if (!expect(sector < nr_sectors))
937 if (!expect(esector < nr_sectors))
938 esector = nr_sectors - 1;
940 /* we set it out of sync,
941 * we do not need to round anything here */
942 sbnr = BM_SECT_TO_BIT(sector);
943 ebnr = BM_SECT_TO_BIT(esector);
945 /* ok, (capacity & 7) != 0 sometimes, but who cares...
946 * we count rs_{total,left} in bits, not sectors. */
947 spin_lock_irqsave(&device->al_lock, flags);
948 count = drbd_bm_set_bits(device, sbnr, ebnr);
950 enr = BM_SECT_TO_EXT(sector);
951 e = lc_find(device->resync, enr);
953 lc_entry(e, struct bm_extent, lce)->rs_left += count;
954 spin_unlock_irqrestore(&device->al_lock, flags);
963 struct bm_extent *_bme_get(struct drbd_device *device, unsigned int enr)
965 struct lc_element *e;
966 struct bm_extent *bm_ext;
968 unsigned long rs_flags;
970 spin_lock_irq(&device->al_lock);
971 if (device->resync_locked > device->resync->nr_elements/2) {
972 spin_unlock_irq(&device->al_lock);
975 e = lc_get(device->resync, enr);
976 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
978 if (bm_ext->lce.lc_number != enr) {
979 bm_ext->rs_left = drbd_bm_e_weight(device, enr);
980 bm_ext->rs_failed = 0;
981 lc_committed(device->resync);
984 if (bm_ext->lce.refcnt == 1)
985 device->resync_locked++;
986 set_bit(BME_NO_WRITES, &bm_ext->flags);
988 rs_flags = device->resync->flags;
989 spin_unlock_irq(&device->al_lock);
991 wake_up(&device->al_wait);
994 if (rs_flags & LC_STARVING)
995 drbd_warn(device, "Have to wait for element"
996 " (resync LRU too small?)\n");
997 BUG_ON(rs_flags & LC_LOCKED);
1003 static int _is_in_al(struct drbd_device *device, unsigned int enr)
1007 spin_lock_irq(&device->al_lock);
1008 rv = lc_is_used(device->act_log, enr);
1009 spin_unlock_irq(&device->al_lock);
1015 * drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED
1016 * @device: DRBD device.
1017 * @sector: The sector number.
1019 * This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted.
1021 int drbd_rs_begin_io(struct drbd_device *device, sector_t sector)
1023 unsigned int enr = BM_SECT_TO_EXT(sector);
1024 struct bm_extent *bm_ext;
1026 int sa = 200; /* Step aside 200 times, then grab the extent and let app-IO wait.
1027 200 times -> 20 seconds. */
1030 sig = wait_event_interruptible(device->al_wait,
1031 (bm_ext = _bme_get(device, enr)));
1035 if (test_bit(BME_LOCKED, &bm_ext->flags))
1038 for (i = 0; i < AL_EXT_PER_BM_SECT; i++) {
1039 sig = wait_event_interruptible(device->al_wait,
1040 !_is_in_al(device, enr * AL_EXT_PER_BM_SECT + i) ||
1041 test_bit(BME_PRIORITY, &bm_ext->flags));
1043 if (sig || (test_bit(BME_PRIORITY, &bm_ext->flags) && sa)) {
1044 spin_lock_irq(&device->al_lock);
1045 if (lc_put(device->resync, &bm_ext->lce) == 0) {
1046 bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */
1047 device->resync_locked--;
1048 wake_up(&device->al_wait);
1050 spin_unlock_irq(&device->al_lock);
1053 if (schedule_timeout_interruptible(HZ/10))
1055 if (sa && --sa == 0)
1056 drbd_warn(device, "drbd_rs_begin_io() stepped aside for 20sec."
1057 "Resync stalled?\n");
1061 set_bit(BME_LOCKED, &bm_ext->flags);
1066 * drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep
1067 * @device: DRBD device.
1068 * @sector: The sector number.
1070 * Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then
1071 * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN
1072 * if there is still application IO going on in this area.
1074 int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector)
1076 unsigned int enr = BM_SECT_TO_EXT(sector);
1077 const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT;
1078 struct lc_element *e;
1079 struct bm_extent *bm_ext;
1082 spin_lock_irq(&device->al_lock);
1083 if (device->resync_wenr != LC_FREE && device->resync_wenr != enr) {
1084 /* in case you have very heavy scattered io, it may
1085 * stall the syncer undefined if we give up the ref count
1086 * when we try again and requeue.
1088 * if we don't give up the refcount, but the next time
1089 * we are scheduled this extent has been "synced" by new
1090 * application writes, we'd miss the lc_put on the
1091 * extent we keep the refcount on.
1092 * so we remembered which extent we had to try again, and
1093 * if the next requested one is something else, we do
1094 * the lc_put here...
1095 * we also have to wake_up
1097 e = lc_find(device->resync, device->resync_wenr);
1098 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1100 D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags));
1101 D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags));
1102 clear_bit(BME_NO_WRITES, &bm_ext->flags);
1103 device->resync_wenr = LC_FREE;
1104 if (lc_put(device->resync, &bm_ext->lce) == 0)
1105 device->resync_locked--;
1106 wake_up(&device->al_wait);
1108 drbd_alert(device, "LOGIC BUG\n");
1112 e = lc_try_get(device->resync, enr);
1113 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1115 if (test_bit(BME_LOCKED, &bm_ext->flags))
1117 if (!test_and_set_bit(BME_NO_WRITES, &bm_ext->flags)) {
1118 device->resync_locked++;
1120 /* we did set the BME_NO_WRITES,
1121 * but then could not set BME_LOCKED,
1122 * so we tried again.
1123 * drop the extra reference. */
1124 bm_ext->lce.refcnt--;
1125 D_ASSERT(device, bm_ext->lce.refcnt > 0);
1129 /* do we rather want to try later? */
1130 if (device->resync_locked > device->resync->nr_elements-3)
1132 /* Do or do not. There is no try. -- Yoda */
1133 e = lc_get(device->resync, enr);
1134 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1136 const unsigned long rs_flags = device->resync->flags;
1137 if (rs_flags & LC_STARVING)
1138 drbd_warn(device, "Have to wait for element"
1139 " (resync LRU too small?)\n");
1140 BUG_ON(rs_flags & LC_LOCKED);
1143 if (bm_ext->lce.lc_number != enr) {
1144 bm_ext->rs_left = drbd_bm_e_weight(device, enr);
1145 bm_ext->rs_failed = 0;
1146 lc_committed(device->resync);
1147 wake_up(&device->al_wait);
1148 D_ASSERT(device, test_bit(BME_LOCKED, &bm_ext->flags) == 0);
1150 set_bit(BME_NO_WRITES, &bm_ext->flags);
1151 D_ASSERT(device, bm_ext->lce.refcnt == 1);
1152 device->resync_locked++;
1156 for (i = 0; i < AL_EXT_PER_BM_SECT; i++) {
1157 if (lc_is_used(device->act_log, al_enr+i))
1160 set_bit(BME_LOCKED, &bm_ext->flags);
1162 device->resync_wenr = LC_FREE;
1163 spin_unlock_irq(&device->al_lock);
1168 device->resync_wenr = enr;
1169 spin_unlock_irq(&device->al_lock);
1173 void drbd_rs_complete_io(struct drbd_device *device, sector_t sector)
1175 unsigned int enr = BM_SECT_TO_EXT(sector);
1176 struct lc_element *e;
1177 struct bm_extent *bm_ext;
1178 unsigned long flags;
1180 spin_lock_irqsave(&device->al_lock, flags);
1181 e = lc_find(device->resync, enr);
1182 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1184 spin_unlock_irqrestore(&device->al_lock, flags);
1185 if (__ratelimit(&drbd_ratelimit_state))
1186 drbd_err(device, "drbd_rs_complete_io() called, but extent not found\n");
1190 if (bm_ext->lce.refcnt == 0) {
1191 spin_unlock_irqrestore(&device->al_lock, flags);
1192 drbd_err(device, "drbd_rs_complete_io(,%llu [=%u]) called, "
1193 "but refcnt is 0!?\n",
1194 (unsigned long long)sector, enr);
1198 if (lc_put(device->resync, &bm_ext->lce) == 0) {
1199 bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */
1200 device->resync_locked--;
1201 wake_up(&device->al_wait);
1204 spin_unlock_irqrestore(&device->al_lock, flags);
1208 * drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED)
1209 * @device: DRBD device.
1211 void drbd_rs_cancel_all(struct drbd_device *device)
1213 spin_lock_irq(&device->al_lock);
1215 if (get_ldev_if_state(device, D_FAILED)) { /* Makes sure ->resync is there. */
1216 lc_reset(device->resync);
1219 device->resync_locked = 0;
1220 device->resync_wenr = LC_FREE;
1221 spin_unlock_irq(&device->al_lock);
1222 wake_up(&device->al_wait);
1226 * drbd_rs_del_all() - Gracefully remove all extents from the resync LRU
1227 * @device: DRBD device.
1229 * Returns 0 upon success, -EAGAIN if at least one reference count was
1232 int drbd_rs_del_all(struct drbd_device *device)
1234 struct lc_element *e;
1235 struct bm_extent *bm_ext;
1238 spin_lock_irq(&device->al_lock);
1240 if (get_ldev_if_state(device, D_FAILED)) {
1241 /* ok, ->resync is there. */
1242 for (i = 0; i < device->resync->nr_elements; i++) {
1243 e = lc_element_by_index(device->resync, i);
1244 bm_ext = lc_entry(e, struct bm_extent, lce);
1245 if (bm_ext->lce.lc_number == LC_FREE)
1247 if (bm_ext->lce.lc_number == device->resync_wenr) {
1248 drbd_info(device, "dropping %u in drbd_rs_del_all, apparently"
1249 " got 'synced' by application io\n",
1250 device->resync_wenr);
1251 D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags));
1252 D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags));
1253 clear_bit(BME_NO_WRITES, &bm_ext->flags);
1254 device->resync_wenr = LC_FREE;
1255 lc_put(device->resync, &bm_ext->lce);
1257 if (bm_ext->lce.refcnt != 0) {
1258 drbd_info(device, "Retrying drbd_rs_del_all() later. "
1259 "refcnt=%d\n", bm_ext->lce.refcnt);
1261 spin_unlock_irq(&device->al_lock);
1264 D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags));
1265 D_ASSERT(device, !test_bit(BME_NO_WRITES, &bm_ext->flags));
1266 lc_del(device->resync, &bm_ext->lce);
1268 D_ASSERT(device, device->resync->used == 0);
1271 spin_unlock_irq(&device->al_lock);
1272 wake_up(&device->al_wait);
1278 * drbd_rs_failed_io() - Record information on a failure to resync the specified blocks
1279 * @device: DRBD device.
1280 * @sector: The sector number.
1281 * @size: Size of failed IO operation, in byte.
1283 void drbd_rs_failed_io(struct drbd_device *device, sector_t sector, int size)
1285 /* Is called from worker and receiver context _only_ */
1286 unsigned long sbnr, ebnr, lbnr;
1287 unsigned long count;
1288 sector_t esector, nr_sectors;
1291 if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
1292 drbd_err(device, "drbd_rs_failed_io: sector=%llus size=%d nonsense!\n",
1293 (unsigned long long)sector, size);
1296 nr_sectors = drbd_get_capacity(device->this_bdev);
1297 esector = sector + (size >> 9) - 1;
1299 if (!expect(sector < nr_sectors))
1301 if (!expect(esector < nr_sectors))
1302 esector = nr_sectors - 1;
1304 lbnr = BM_SECT_TO_BIT(nr_sectors-1);
1307 * round up start sector, round down end sector. we make sure we only
1308 * handle full, aligned, BM_BLOCK_SIZE (4K) blocks */
1309 if (unlikely(esector < BM_SECT_PER_BIT-1))
1311 if (unlikely(esector == (nr_sectors-1)))
1314 ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1));
1315 sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1);
1321 * ok, (capacity & 7) != 0 sometimes, but who cares...
1322 * we count rs_{total,left} in bits, not sectors.
1324 spin_lock_irq(&device->al_lock);
1325 count = drbd_bm_count_bits(device, sbnr, ebnr);
1327 device->rs_failed += count;
1329 if (get_ldev(device)) {
1330 drbd_try_clear_on_disk_bm(device, sector, count, false);
1334 /* just wake_up unconditional now, various lc_chaged(),
1335 * lc_put() in drbd_try_clear_on_disk_bm(). */
1338 spin_unlock_irq(&device->al_lock);
1340 wake_up(&device->al_wait);