1 | /* |
2 | drbd_actlog.c |
3 | |
4 | This file is part of DRBD by Philipp Reisner and Lars Ellenberg. |
5 | |
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>. |
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/slab.h> |
27 | #include <linux/crc32c.h> |
28 | #include <linux/drbd.h> |
29 | #include <linux/drbd_limits.h> |
30 | #include "drbd_int.h" |
31 | |
32 | |
33 | enum al_transaction_types { |
34 | AL_TR_UPDATE = 0, |
35 | AL_TR_INITIALIZED = 0xffff |
36 | }; |
37 | /* all fields on disc in big endian */ |
38 | struct __packed al_transaction_on_disk { |
39 | /* don't we all like magic */ |
40 | __be32 magic; |
41 | |
42 | /* to identify the most recent transaction block |
43 | * in the on disk ring buffer */ |
44 | __be32 tr_number; |
45 | |
46 | /* checksum on the full 4k block, with this field set to 0. */ |
47 | __be32 crc32c; |
48 | |
49 | /* type of transaction, special transaction types like: |
50 | * purge-all, set-all-idle, set-all-active, ... to-be-defined |
51 | * see also enum al_transaction_types */ |
52 | __be16 transaction_type; |
53 | |
54 | /* we currently allow only a few thousand extents, |
55 | * so 16bit will be enough for the slot number. */ |
56 | |
57 | /* how many updates in this transaction */ |
58 | __be16 n_updates; |
59 | |
60 | /* maximum slot number, "al-extents" in drbd.conf speak. |
61 | * Having this in each transaction should make reconfiguration |
62 | * of that parameter easier. */ |
63 | __be16 context_size; |
64 | |
65 | /* slot number the context starts with */ |
66 | __be16 context_start_slot_nr; |
67 | |
68 | /* Some reserved bytes. Expected usage is a 64bit counter of |
69 | * sectors-written since device creation, and other data generation tag |
70 | * supporting usage */ |
71 | __be32 __reserved[4]; |
72 | |
73 | /* --- 36 byte used --- */ |
74 | |
75 | /* Reserve space for up to AL_UPDATES_PER_TRANSACTION changes |
76 | * in one transaction, then use the remaining byte in the 4k block for |
77 | * context information. "Flexible" number of updates per transaction |
78 | * does not help, as we have to account for the case when all update |
79 | * slots are used anyways, so it would only complicate code without |
80 | * additional benefit. |
81 | */ |
82 | __be16 update_slot_nr[AL_UPDATES_PER_TRANSACTION]; |
83 | |
84 | /* but the extent number is 32bit, which at an extent size of 4 MiB |
85 | * allows to cover device sizes of up to 2**54 Byte (16 PiB) */ |
86 | __be32 update_extent_nr[AL_UPDATES_PER_TRANSACTION]; |
87 | |
88 | /* --- 420 bytes used (36 + 64*6) --- */ |
89 | |
90 | /* 4096 - 420 = 3676 = 919 * 4 */ |
91 | __be32 context[AL_CONTEXT_PER_TRANSACTION]; |
92 | }; |
93 | |
94 | void *drbd_md_get_buffer(struct drbd_device *device, const char *intent) |
95 | { |
96 | int r; |
97 | |
98 | wait_event(device->misc_wait, |
99 | (r = atomic_cmpxchg(&device->md_io.in_use, 0, 1)) == 0 || |
100 | device->state.disk <= D_FAILED); |
101 | |
102 | if (r) |
103 | return NULL; |
104 | |
105 | device->md_io.current_use = intent; |
106 | device->md_io.start_jif = jiffies; |
107 | device->md_io.submit_jif = device->md_io.start_jif - 1; |
108 | return page_address(device->md_io.page); |
109 | } |
110 | |
111 | void drbd_md_put_buffer(struct drbd_device *device) |
112 | { |
113 | if (atomic_dec_and_test(&device->md_io.in_use)) |
114 | wake_up(&device->misc_wait); |
115 | } |
116 | |
117 | void wait_until_done_or_force_detached(struct drbd_device *device, struct drbd_backing_dev *bdev, |
118 | unsigned int *done) |
119 | { |
120 | long dt; |
121 | |
122 | rcu_read_lock(); |
123 | dt = rcu_dereference(bdev->disk_conf)->disk_timeout; |
124 | rcu_read_unlock(); |
125 | dt = dt * HZ / 10; |
126 | if (dt == 0) |
127 | dt = MAX_SCHEDULE_TIMEOUT; |
128 | |
129 | dt = wait_event_timeout(device->misc_wait, |
130 | *done || test_bit(FORCE_DETACH, &device->flags), dt); |
131 | if (dt == 0) { |
132 | drbd_err(device, "meta-data IO operation timed out\n" ); |
133 | drbd_chk_io_error(device, 1, DRBD_FORCE_DETACH); |
134 | } |
135 | } |
136 | |
137 | static int _drbd_md_sync_page_io(struct drbd_device *device, |
138 | struct drbd_backing_dev *bdev, |
139 | sector_t sector, int op) |
140 | { |
141 | struct bio *bio; |
142 | /* we do all our meta data IO in aligned 4k blocks. */ |
143 | const int size = 4096; |
144 | int err, op_flags = 0; |
145 | |
146 | device->md_io.done = 0; |
147 | device->md_io.error = -ENODEV; |
148 | |
149 | if ((op == REQ_OP_WRITE) && !test_bit(MD_NO_FUA, &device->flags)) |
150 | op_flags |= REQ_FUA | REQ_PREFLUSH; |
151 | op_flags |= REQ_SYNC; |
152 | |
153 | bio = bio_alloc_drbd(GFP_NOIO); |
154 | bio_set_dev(bio, bdev->md_bdev); |
155 | bio->bi_iter.bi_sector = sector; |
156 | err = -EIO; |
157 | if (bio_add_page(bio, device->md_io.page, size, 0) != size) |
158 | goto out; |
159 | bio->bi_private = device; |
160 | bio->bi_end_io = drbd_md_endio; |
161 | bio_set_op_attrs(bio, op, op_flags); |
162 | |
163 | if (op != REQ_OP_WRITE && device->state.disk == D_DISKLESS && device->ldev == NULL) |
164 | /* special case, drbd_md_read() during drbd_adm_attach(): no get_ldev */ |
165 | ; |
166 | else if (!get_ldev_if_state(device, D_ATTACHING)) { |
167 | /* Corresponding put_ldev in drbd_md_endio() */ |
168 | drbd_err(device, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n" ); |
169 | err = -ENODEV; |
170 | goto out; |
171 | } |
172 | |
173 | bio_get(bio); /* one bio_put() is in the completion handler */ |
174 | atomic_inc(&device->md_io.in_use); /* drbd_md_put_buffer() is in the completion handler */ |
175 | device->md_io.submit_jif = jiffies; |
176 | if (drbd_insert_fault(device, (op == REQ_OP_WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) |
177 | bio_io_error(bio); |
178 | else |
179 | submit_bio(bio); |
180 | wait_until_done_or_force_detached(device, bdev, &device->md_io.done); |
181 | if (!bio->bi_status) |
182 | err = device->md_io.error; |
183 | |
184 | out: |
185 | bio_put(bio); |
186 | return err; |
187 | } |
188 | |
189 | int drbd_md_sync_page_io(struct drbd_device *device, struct drbd_backing_dev *bdev, |
190 | sector_t sector, int op) |
191 | { |
192 | int err; |
193 | D_ASSERT(device, atomic_read(&device->md_io.in_use) == 1); |
194 | |
195 | BUG_ON(!bdev->md_bdev); |
196 | |
197 | dynamic_drbd_dbg(device, "meta_data io: %s [%d]:%s(,%llus,%s) %pS\n" , |
198 | current->comm, current->pid, __func__, |
199 | (unsigned long long)sector, (op == REQ_OP_WRITE) ? "WRITE" : "READ" , |
200 | (void*)_RET_IP_ ); |
201 | |
202 | if (sector < drbd_md_first_sector(bdev) || |
203 | sector + 7 > drbd_md_last_sector(bdev)) |
204 | drbd_alert(device, "%s [%d]:%s(,%llus,%s) out of range md access!\n" , |
205 | current->comm, current->pid, __func__, |
206 | (unsigned long long)sector, |
207 | (op == REQ_OP_WRITE) ? "WRITE" : "READ" ); |
208 | |
209 | err = _drbd_md_sync_page_io(device, bdev, sector, op); |
210 | if (err) { |
211 | drbd_err(device, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n" , |
212 | (unsigned long long)sector, |
213 | (op == REQ_OP_WRITE) ? "WRITE" : "READ" , err); |
214 | } |
215 | return err; |
216 | } |
217 | |
218 | static struct bm_extent *find_active_resync_extent(struct drbd_device *device, unsigned int enr) |
219 | { |
220 | struct lc_element *tmp; |
221 | tmp = lc_find(device->resync, enr/AL_EXT_PER_BM_SECT); |
222 | if (unlikely(tmp != NULL)) { |
223 | struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); |
224 | if (test_bit(BME_NO_WRITES, &bm_ext->flags)) |
225 | return bm_ext; |
226 | } |
227 | return NULL; |
228 | } |
229 | |
230 | static struct lc_element *_al_get(struct drbd_device *device, unsigned int enr, bool nonblock) |
231 | { |
232 | struct lc_element *al_ext; |
233 | struct bm_extent *bm_ext; |
234 | int wake; |
235 | |
236 | spin_lock_irq(&device->al_lock); |
237 | bm_ext = find_active_resync_extent(device, enr); |
238 | if (bm_ext) { |
239 | wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags); |
240 | spin_unlock_irq(&device->al_lock); |
241 | if (wake) |
242 | wake_up(&device->al_wait); |
243 | return NULL; |
244 | } |
245 | if (nonblock) |
246 | al_ext = lc_try_get(device->act_log, enr); |
247 | else |
248 | al_ext = lc_get(device->act_log, enr); |
249 | spin_unlock_irq(&device->al_lock); |
250 | return al_ext; |
251 | } |
252 | |
253 | bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i) |
254 | { |
255 | /* for bios crossing activity log extent boundaries, |
256 | * we may need to activate two extents in one go */ |
257 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
258 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
259 | |
260 | D_ASSERT(device, first <= last); |
261 | D_ASSERT(device, atomic_read(&device->local_cnt) > 0); |
262 | |
263 | /* FIXME figure out a fast path for bios crossing AL extent boundaries */ |
264 | if (first != last) |
265 | return false; |
266 | |
267 | return _al_get(device, first, true); |
268 | } |
269 | |
270 | bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i) |
271 | { |
272 | /* for bios crossing activity log extent boundaries, |
273 | * we may need to activate two extents in one go */ |
274 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
275 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
276 | unsigned enr; |
277 | bool need_transaction = false; |
278 | |
279 | D_ASSERT(device, first <= last); |
280 | D_ASSERT(device, atomic_read(&device->local_cnt) > 0); |
281 | |
282 | for (enr = first; enr <= last; enr++) { |
283 | struct lc_element *al_ext; |
284 | wait_event(device->al_wait, |
285 | (al_ext = _al_get(device, enr, false)) != NULL); |
286 | if (al_ext->lc_number != enr) |
287 | need_transaction = true; |
288 | } |
289 | return need_transaction; |
290 | } |
291 | |
292 | #if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT) |
293 | /* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT |
294 | * are still coupled, or assume too much about their relation. |
295 | * Code below will not work if this is violated. |
296 | * Will be cleaned up with some followup patch. |
297 | */ |
298 | # error FIXME |
299 | #endif |
300 | |
301 | static unsigned int al_extent_to_bm_page(unsigned int al_enr) |
302 | { |
303 | return al_enr >> |
304 | /* bit to page */ |
305 | ((PAGE_SHIFT + 3) - |
306 | /* al extent number to bit */ |
307 | (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)); |
308 | } |
309 | |
310 | static sector_t al_tr_number_to_on_disk_sector(struct drbd_device *device) |
311 | { |
312 | const unsigned int stripes = device->ldev->md.al_stripes; |
313 | const unsigned int stripe_size_4kB = device->ldev->md.al_stripe_size_4k; |
314 | |
315 | /* transaction number, modulo on-disk ring buffer wrap around */ |
316 | unsigned int t = device->al_tr_number % (device->ldev->md.al_size_4k); |
317 | |
318 | /* ... to aligned 4k on disk block */ |
319 | t = ((t % stripes) * stripe_size_4kB) + t/stripes; |
320 | |
321 | /* ... to 512 byte sector in activity log */ |
322 | t *= 8; |
323 | |
324 | /* ... plus offset to the on disk position */ |
325 | return device->ldev->md.md_offset + device->ldev->md.al_offset + t; |
326 | } |
327 | |
328 | static int __al_write_transaction(struct drbd_device *device, struct al_transaction_on_disk *buffer) |
329 | { |
330 | struct lc_element *e; |
331 | sector_t sector; |
332 | int i, mx; |
333 | unsigned extent_nr; |
334 | unsigned crc = 0; |
335 | int err = 0; |
336 | |
337 | memset(buffer, 0, sizeof(*buffer)); |
338 | buffer->magic = cpu_to_be32(DRBD_AL_MAGIC); |
339 | buffer->tr_number = cpu_to_be32(device->al_tr_number); |
340 | |
341 | i = 0; |
342 | |
343 | drbd_bm_reset_al_hints(device); |
344 | |
345 | /* Even though no one can start to change this list |
346 | * once we set the LC_LOCKED -- from drbd_al_begin_io(), |
347 | * lc_try_lock_for_transaction() --, someone may still |
348 | * be in the process of changing it. */ |
349 | spin_lock_irq(&device->al_lock); |
350 | list_for_each_entry(e, &device->act_log->to_be_changed, list) { |
351 | if (i == AL_UPDATES_PER_TRANSACTION) { |
352 | i++; |
353 | break; |
354 | } |
355 | buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index); |
356 | buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number); |
357 | if (e->lc_number != LC_FREE) |
358 | drbd_bm_mark_for_writeout(device, |
359 | al_extent_to_bm_page(e->lc_number)); |
360 | i++; |
361 | } |
362 | spin_unlock_irq(&device->al_lock); |
363 | BUG_ON(i > AL_UPDATES_PER_TRANSACTION); |
364 | |
365 | buffer->n_updates = cpu_to_be16(i); |
366 | for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) { |
367 | buffer->update_slot_nr[i] = cpu_to_be16(-1); |
368 | buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE); |
369 | } |
370 | |
371 | buffer->context_size = cpu_to_be16(device->act_log->nr_elements); |
372 | buffer->context_start_slot_nr = cpu_to_be16(device->al_tr_cycle); |
373 | |
374 | mx = min_t(int, AL_CONTEXT_PER_TRANSACTION, |
375 | device->act_log->nr_elements - device->al_tr_cycle); |
376 | for (i = 0; i < mx; i++) { |
377 | unsigned idx = device->al_tr_cycle + i; |
378 | extent_nr = lc_element_by_index(device->act_log, idx)->lc_number; |
379 | buffer->context[i] = cpu_to_be32(extent_nr); |
380 | } |
381 | for (; i < AL_CONTEXT_PER_TRANSACTION; i++) |
382 | buffer->context[i] = cpu_to_be32(LC_FREE); |
383 | |
384 | device->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION; |
385 | if (device->al_tr_cycle >= device->act_log->nr_elements) |
386 | device->al_tr_cycle = 0; |
387 | |
388 | sector = al_tr_number_to_on_disk_sector(device); |
389 | |
390 | crc = crc32c(0, buffer, 4096); |
391 | buffer->crc32c = cpu_to_be32(crc); |
392 | |
393 | if (drbd_bm_write_hinted(device)) |
394 | err = -EIO; |
395 | else { |
396 | bool write_al_updates; |
397 | rcu_read_lock(); |
398 | write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates; |
399 | rcu_read_unlock(); |
400 | if (write_al_updates) { |
401 | if (drbd_md_sync_page_io(device, device->ldev, sector, WRITE)) { |
402 | err = -EIO; |
403 | drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR); |
404 | } else { |
405 | device->al_tr_number++; |
406 | device->al_writ_cnt++; |
407 | } |
408 | } |
409 | } |
410 | |
411 | return err; |
412 | } |
413 | |
414 | static int al_write_transaction(struct drbd_device *device) |
415 | { |
416 | struct al_transaction_on_disk *buffer; |
417 | int err; |
418 | |
419 | if (!get_ldev(device)) { |
420 | drbd_err(device, "disk is %s, cannot start al transaction\n" , |
421 | drbd_disk_str(device->state.disk)); |
422 | return -EIO; |
423 | } |
424 | |
425 | /* The bitmap write may have failed, causing a state change. */ |
426 | if (device->state.disk < D_INCONSISTENT) { |
427 | drbd_err(device, |
428 | "disk is %s, cannot write al transaction\n" , |
429 | drbd_disk_str(device->state.disk)); |
430 | put_ldev(device); |
431 | return -EIO; |
432 | } |
433 | |
434 | /* protects md_io_buffer, al_tr_cycle, ... */ |
435 | buffer = drbd_md_get_buffer(device, __func__); |
436 | if (!buffer) { |
437 | drbd_err(device, "disk failed while waiting for md_io buffer\n" ); |
438 | put_ldev(device); |
439 | return -ENODEV; |
440 | } |
441 | |
442 | err = __al_write_transaction(device, buffer); |
443 | |
444 | drbd_md_put_buffer(device); |
445 | put_ldev(device); |
446 | |
447 | return err; |
448 | } |
449 | |
450 | |
451 | void drbd_al_begin_io_commit(struct drbd_device *device) |
452 | { |
453 | bool locked = false; |
454 | |
455 | /* Serialize multiple transactions. |
456 | * This uses test_and_set_bit, memory barrier is implicit. |
457 | */ |
458 | wait_event(device->al_wait, |
459 | device->act_log->pending_changes == 0 || |
460 | (locked = lc_try_lock_for_transaction(device->act_log))); |
461 | |
462 | if (locked) { |
463 | /* Double check: it may have been committed by someone else, |
464 | * while we have been waiting for the lock. */ |
465 | if (device->act_log->pending_changes) { |
466 | bool write_al_updates; |
467 | |
468 | rcu_read_lock(); |
469 | write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates; |
470 | rcu_read_unlock(); |
471 | |
472 | if (write_al_updates) |
473 | al_write_transaction(device); |
474 | spin_lock_irq(&device->al_lock); |
475 | /* FIXME |
476 | if (err) |
477 | we need an "lc_cancel" here; |
478 | */ |
479 | lc_committed(device->act_log); |
480 | spin_unlock_irq(&device->al_lock); |
481 | } |
482 | lc_unlock(device->act_log); |
483 | wake_up(&device->al_wait); |
484 | } |
485 | } |
486 | |
487 | /* |
488 | * @delegate: delegate activity log I/O to the worker thread |
489 | */ |
490 | void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i) |
491 | { |
492 | if (drbd_al_begin_io_prepare(device, i)) |
493 | drbd_al_begin_io_commit(device); |
494 | } |
495 | |
496 | int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i) |
497 | { |
498 | struct lru_cache *al = device->act_log; |
499 | /* for bios crossing activity log extent boundaries, |
500 | * we may need to activate two extents in one go */ |
501 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
502 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
503 | unsigned nr_al_extents; |
504 | unsigned available_update_slots; |
505 | unsigned enr; |
506 | |
507 | D_ASSERT(device, first <= last); |
508 | |
509 | nr_al_extents = 1 + last - first; /* worst case: all touched extends are cold. */ |
510 | available_update_slots = min(al->nr_elements - al->used, |
511 | al->max_pending_changes - al->pending_changes); |
512 | |
513 | /* We want all necessary updates for a given request within the same transaction |
514 | * We could first check how many updates are *actually* needed, |
515 | * and use that instead of the worst-case nr_al_extents */ |
516 | if (available_update_slots < nr_al_extents) { |
517 | /* Too many activity log extents are currently "hot". |
518 | * |
519 | * If we have accumulated pending changes already, |
520 | * we made progress. |
521 | * |
522 | * If we cannot get even a single pending change through, |
523 | * stop the fast path until we made some progress, |
524 | * or requests to "cold" extents could be starved. */ |
525 | if (!al->pending_changes) |
526 | __set_bit(__LC_STARVING, &device->act_log->flags); |
527 | return -ENOBUFS; |
528 | } |
529 | |
530 | /* Is resync active in this area? */ |
531 | for (enr = first; enr <= last; enr++) { |
532 | struct lc_element *tmp; |
533 | tmp = lc_find(device->resync, enr/AL_EXT_PER_BM_SECT); |
534 | if (unlikely(tmp != NULL)) { |
535 | struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); |
536 | if (test_bit(BME_NO_WRITES, &bm_ext->flags)) { |
537 | if (!test_and_set_bit(BME_PRIORITY, &bm_ext->flags)) |
538 | return -EBUSY; |
539 | return -EWOULDBLOCK; |
540 | } |
541 | } |
542 | } |
543 | |
544 | /* Checkout the refcounts. |
545 | * Given that we checked for available elements and update slots above, |
546 | * this has to be successful. */ |
547 | for (enr = first; enr <= last; enr++) { |
548 | struct lc_element *al_ext; |
549 | al_ext = lc_get_cumulative(device->act_log, enr); |
550 | if (!al_ext) |
551 | drbd_info(device, "LOGIC BUG for enr=%u\n" , enr); |
552 | } |
553 | return 0; |
554 | } |
555 | |
556 | void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i) |
557 | { |
558 | /* for bios crossing activity log extent boundaries, |
559 | * we may need to activate two extents in one go */ |
560 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
561 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
562 | unsigned enr; |
563 | struct lc_element *extent; |
564 | unsigned long flags; |
565 | |
566 | D_ASSERT(device, first <= last); |
567 | spin_lock_irqsave(&device->al_lock, flags); |
568 | |
569 | for (enr = first; enr <= last; enr++) { |
570 | extent = lc_find(device->act_log, enr); |
571 | if (!extent) { |
572 | drbd_err(device, "al_complete_io() called on inactive extent %u\n" , enr); |
573 | continue; |
574 | } |
575 | lc_put(device->act_log, extent); |
576 | } |
577 | spin_unlock_irqrestore(&device->al_lock, flags); |
578 | wake_up(&device->al_wait); |
579 | } |
580 | |
581 | static int _try_lc_del(struct drbd_device *device, struct lc_element *al_ext) |
582 | { |
583 | int rv; |
584 | |
585 | spin_lock_irq(&device->al_lock); |
586 | rv = (al_ext->refcnt == 0); |
587 | if (likely(rv)) |
588 | lc_del(device->act_log, al_ext); |
589 | spin_unlock_irq(&device->al_lock); |
590 | |
591 | return rv; |
592 | } |
593 | |
594 | /** |
595 | * drbd_al_shrink() - Removes all active extents form the activity log |
596 | * @device: DRBD device. |
597 | * |
598 | * Removes all active extents form the activity log, waiting until |
599 | * the reference count of each entry dropped to 0 first, of course. |
600 | * |
601 | * You need to lock device->act_log with lc_try_lock() / lc_unlock() |
602 | */ |
603 | void drbd_al_shrink(struct drbd_device *device) |
604 | { |
605 | struct lc_element *al_ext; |
606 | int i; |
607 | |
608 | D_ASSERT(device, test_bit(__LC_LOCKED, &device->act_log->flags)); |
609 | |
610 | for (i = 0; i < device->act_log->nr_elements; i++) { |
611 | al_ext = lc_element_by_index(device->act_log, i); |
612 | if (al_ext->lc_number == LC_FREE) |
613 | continue; |
614 | wait_event(device->al_wait, _try_lc_del(device, al_ext)); |
615 | } |
616 | |
617 | wake_up(&device->al_wait); |
618 | } |
619 | |
620 | int drbd_al_initialize(struct drbd_device *device, void *buffer) |
621 | { |
622 | struct al_transaction_on_disk *al = buffer; |
623 | struct drbd_md *md = &device->ldev->md; |
624 | int al_size_4k = md->al_stripes * md->al_stripe_size_4k; |
625 | int i; |
626 | |
627 | __al_write_transaction(device, al); |
628 | /* There may or may not have been a pending transaction. */ |
629 | spin_lock_irq(&device->al_lock); |
630 | lc_committed(device->act_log); |
631 | spin_unlock_irq(&device->al_lock); |
632 | |
633 | /* The rest of the transactions will have an empty "updates" list, and |
634 | * are written out only to provide the context, and to initialize the |
635 | * on-disk ring buffer. */ |
636 | for (i = 1; i < al_size_4k; i++) { |
637 | int err = __al_write_transaction(device, al); |
638 | if (err) |
639 | return err; |
640 | } |
641 | return 0; |
642 | } |
643 | |
644 | static const char *drbd_change_sync_fname[] = { |
645 | [RECORD_RS_FAILED] = "drbd_rs_failed_io" , |
646 | [SET_IN_SYNC] = "drbd_set_in_sync" , |
647 | [SET_OUT_OF_SYNC] = "drbd_set_out_of_sync" |
648 | }; |
649 | |
650 | /* ATTENTION. The AL's extents are 4MB each, while the extents in the |
651 | * resync LRU-cache are 16MB each. |
652 | * The caller of this function has to hold an get_ldev() reference. |
653 | * |
654 | * Adjusts the caching members ->rs_left (success) or ->rs_failed (!success), |
655 | * potentially pulling in (and recounting the corresponding bits) |
656 | * this resync extent into the resync extent lru cache. |
657 | * |
658 | * Returns whether all bits have been cleared for this resync extent, |
659 | * precisely: (rs_left <= rs_failed) |
660 | * |
661 | * TODO will be obsoleted once we have a caching lru of the on disk bitmap |
662 | */ |
663 | static bool update_rs_extent(struct drbd_device *device, |
664 | unsigned int enr, int count, |
665 | enum update_sync_bits_mode mode) |
666 | { |
667 | struct lc_element *e; |
668 | |
669 | D_ASSERT(device, atomic_read(&device->local_cnt)); |
670 | |
671 | /* When setting out-of-sync bits, |
672 | * we don't need it cached (lc_find). |
673 | * But if it is present in the cache, |
674 | * we should update the cached bit count. |
675 | * Otherwise, that extent should be in the resync extent lru cache |
676 | * already -- or we want to pull it in if necessary -- (lc_get), |
677 | * then update and check rs_left and rs_failed. */ |
678 | if (mode == SET_OUT_OF_SYNC) |
679 | e = lc_find(device->resync, enr); |
680 | else |
681 | e = lc_get(device->resync, enr); |
682 | if (e) { |
683 | struct bm_extent *ext = lc_entry(e, struct bm_extent, lce); |
684 | if (ext->lce.lc_number == enr) { |
685 | if (mode == SET_IN_SYNC) |
686 | ext->rs_left -= count; |
687 | else if (mode == SET_OUT_OF_SYNC) |
688 | ext->rs_left += count; |
689 | else |
690 | ext->rs_failed += count; |
691 | if (ext->rs_left < ext->rs_failed) { |
692 | drbd_warn(device, "BAD! enr=%u rs_left=%d " |
693 | "rs_failed=%d count=%d cstate=%s\n" , |
694 | ext->lce.lc_number, ext->rs_left, |
695 | ext->rs_failed, count, |
696 | drbd_conn_str(device->state.conn)); |
697 | |
698 | /* We don't expect to be able to clear more bits |
699 | * than have been set when we originally counted |
700 | * the set bits to cache that value in ext->rs_left. |
701 | * Whatever the reason (disconnect during resync, |
702 | * delayed local completion of an application write), |
703 | * try to fix it up by recounting here. */ |
704 | ext->rs_left = drbd_bm_e_weight(device, enr); |
705 | } |
706 | } else { |
707 | /* Normally this element should be in the cache, |
708 | * since drbd_rs_begin_io() pulled it already in. |
709 | * |
710 | * But maybe an application write finished, and we set |
711 | * something outside the resync lru_cache in sync. |
712 | */ |
713 | int rs_left = drbd_bm_e_weight(device, enr); |
714 | if (ext->flags != 0) { |
715 | drbd_warn(device, "changing resync lce: %d[%u;%02lx]" |
716 | " -> %d[%u;00]\n" , |
717 | ext->lce.lc_number, ext->rs_left, |
718 | ext->flags, enr, rs_left); |
719 | ext->flags = 0; |
720 | } |
721 | if (ext->rs_failed) { |
722 | drbd_warn(device, "Kicking resync_lru element enr=%u " |
723 | "out with rs_failed=%d\n" , |
724 | ext->lce.lc_number, ext->rs_failed); |
725 | } |
726 | ext->rs_left = rs_left; |
727 | ext->rs_failed = (mode == RECORD_RS_FAILED) ? count : 0; |
728 | /* we don't keep a persistent log of the resync lru, |
729 | * we can commit any change right away. */ |
730 | lc_committed(device->resync); |
731 | } |
732 | if (mode != SET_OUT_OF_SYNC) |
733 | lc_put(device->resync, &ext->lce); |
734 | /* no race, we are within the al_lock! */ |
735 | |
736 | if (ext->rs_left <= ext->rs_failed) { |
737 | ext->rs_failed = 0; |
738 | return true; |
739 | } |
740 | } else if (mode != SET_OUT_OF_SYNC) { |
741 | /* be quiet if lc_find() did not find it. */ |
742 | drbd_err(device, "lc_get() failed! locked=%d/%d flags=%lu\n" , |
743 | device->resync_locked, |
744 | device->resync->nr_elements, |
745 | device->resync->flags); |
746 | } |
747 | return false; |
748 | } |
749 | |
750 | void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go) |
751 | { |
752 | unsigned long now = jiffies; |
753 | unsigned long last = device->rs_mark_time[device->rs_last_mark]; |
754 | int next = (device->rs_last_mark + 1) % DRBD_SYNC_MARKS; |
755 | if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) { |
756 | if (device->rs_mark_left[device->rs_last_mark] != still_to_go && |
757 | device->state.conn != C_PAUSED_SYNC_T && |
758 | device->state.conn != C_PAUSED_SYNC_S) { |
759 | device->rs_mark_time[next] = now; |
760 | device->rs_mark_left[next] = still_to_go; |
761 | device->rs_last_mark = next; |
762 | } |
763 | } |
764 | } |
765 | |
766 | /* It is called lazy update, so don't do write-out too often. */ |
767 | static bool lazy_bitmap_update_due(struct drbd_device *device) |
768 | { |
769 | return time_after(jiffies, device->rs_last_bcast + 2*HZ); |
770 | } |
771 | |
772 | static void maybe_schedule_on_disk_bitmap_update(struct drbd_device *device, bool rs_done) |
773 | { |
774 | if (rs_done) { |
775 | struct drbd_connection *connection = first_peer_device(device)->connection; |
776 | if (connection->agreed_pro_version <= 95 || |
777 | is_sync_target_state(device->state.conn)) |
778 | set_bit(RS_DONE, &device->flags); |
779 | /* and also set RS_PROGRESS below */ |
780 | |
781 | /* Else: rather wait for explicit notification via receive_state, |
782 | * to avoid uuids-rotated-too-fast causing full resync |
783 | * in next handshake, in case the replication link breaks |
784 | * at the most unfortunate time... */ |
785 | } else if (!lazy_bitmap_update_due(device)) |
786 | return; |
787 | |
788 | drbd_device_post_work(device, RS_PROGRESS); |
789 | } |
790 | |
791 | static int update_sync_bits(struct drbd_device *device, |
792 | unsigned long sbnr, unsigned long ebnr, |
793 | enum update_sync_bits_mode mode) |
794 | { |
795 | /* |
796 | * We keep a count of set bits per resync-extent in the ->rs_left |
797 | * caching member, so we need to loop and work within the resync extent |
798 | * alignment. Typically this loop will execute exactly once. |
799 | */ |
800 | unsigned long flags; |
801 | unsigned long count = 0; |
802 | unsigned int cleared = 0; |
803 | while (sbnr <= ebnr) { |
804 | /* set temporary boundary bit number to last bit number within |
805 | * the resync extent of the current start bit number, |
806 | * but cap at provided end bit number */ |
807 | unsigned long tbnr = min(ebnr, sbnr | BM_BLOCKS_PER_BM_EXT_MASK); |
808 | unsigned long c; |
809 | |
810 | if (mode == RECORD_RS_FAILED) |
811 | /* Only called from drbd_rs_failed_io(), bits |
812 | * supposedly still set. Recount, maybe some |
813 | * of the bits have been successfully cleared |
814 | * by application IO meanwhile. |
815 | */ |
816 | c = drbd_bm_count_bits(device, sbnr, tbnr); |
817 | else if (mode == SET_IN_SYNC) |
818 | c = drbd_bm_clear_bits(device, sbnr, tbnr); |
819 | else /* if (mode == SET_OUT_OF_SYNC) */ |
820 | c = drbd_bm_set_bits(device, sbnr, tbnr); |
821 | |
822 | if (c) { |
823 | spin_lock_irqsave(&device->al_lock, flags); |
824 | cleared += update_rs_extent(device, BM_BIT_TO_EXT(sbnr), c, mode); |
825 | spin_unlock_irqrestore(&device->al_lock, flags); |
826 | count += c; |
827 | } |
828 | sbnr = tbnr + 1; |
829 | } |
830 | if (count) { |
831 | if (mode == SET_IN_SYNC) { |
832 | unsigned long still_to_go = drbd_bm_total_weight(device); |
833 | bool rs_is_done = (still_to_go <= device->rs_failed); |
834 | drbd_advance_rs_marks(device, still_to_go); |
835 | if (cleared || rs_is_done) |
836 | maybe_schedule_on_disk_bitmap_update(device, rs_is_done); |
837 | } else if (mode == RECORD_RS_FAILED) |
838 | device->rs_failed += count; |
839 | wake_up(&device->al_wait); |
840 | } |
841 | return count; |
842 | } |
843 | |
844 | static bool plausible_request_size(int size) |
845 | { |
846 | return size > 0 |
847 | && size <= DRBD_MAX_BATCH_BIO_SIZE |
848 | && IS_ALIGNED(size, 512); |
849 | } |
850 | |
851 | /* clear the bit corresponding to the piece of storage in question: |
852 | * size byte of data starting from sector. Only clear a bits of the affected |
853 | * one ore more _aligned_ BM_BLOCK_SIZE blocks. |
854 | * |
855 | * called by worker on C_SYNC_TARGET and receiver on SyncSource. |
856 | * |
857 | */ |
858 | int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size, |
859 | enum update_sync_bits_mode mode) |
860 | { |
861 | /* Is called from worker and receiver context _only_ */ |
862 | unsigned long sbnr, ebnr, lbnr; |
863 | unsigned long count = 0; |
864 | sector_t esector, nr_sectors; |
865 | |
866 | /* This would be an empty REQ_PREFLUSH, be silent. */ |
867 | if ((mode == SET_OUT_OF_SYNC) && size == 0) |
868 | return 0; |
869 | |
870 | if (!plausible_request_size(size)) { |
871 | drbd_err(device, "%s: sector=%llus size=%d nonsense!\n" , |
872 | drbd_change_sync_fname[mode], |
873 | (unsigned long long)sector, size); |
874 | return 0; |
875 | } |
876 | |
877 | if (!get_ldev(device)) |
878 | return 0; /* no disk, no metadata, no bitmap to manipulate bits in */ |
879 | |
880 | nr_sectors = drbd_get_capacity(device->this_bdev); |
881 | esector = sector + (size >> 9) - 1; |
882 | |
883 | if (!expect(sector < nr_sectors)) |
884 | goto out; |
885 | if (!expect(esector < nr_sectors)) |
886 | esector = nr_sectors - 1; |
887 | |
888 | lbnr = BM_SECT_TO_BIT(nr_sectors-1); |
889 | |
890 | if (mode == SET_IN_SYNC) { |
891 | /* Round up start sector, round down end sector. We make sure |
892 | * we only clear full, aligned, BM_BLOCK_SIZE blocks. */ |
893 | if (unlikely(esector < BM_SECT_PER_BIT-1)) |
894 | goto out; |
895 | if (unlikely(esector == (nr_sectors-1))) |
896 | ebnr = lbnr; |
897 | else |
898 | ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1)); |
899 | sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1); |
900 | } else { |
901 | /* We set it out of sync, or record resync failure. |
902 | * Should not round anything here. */ |
903 | sbnr = BM_SECT_TO_BIT(sector); |
904 | ebnr = BM_SECT_TO_BIT(esector); |
905 | } |
906 | |
907 | count = update_sync_bits(device, sbnr, ebnr, mode); |
908 | out: |
909 | put_ldev(device); |
910 | return count; |
911 | } |
912 | |
913 | static |
914 | struct bm_extent *_bme_get(struct drbd_device *device, unsigned int enr) |
915 | { |
916 | struct lc_element *e; |
917 | struct bm_extent *bm_ext; |
918 | int wakeup = 0; |
919 | unsigned long rs_flags; |
920 | |
921 | spin_lock_irq(&device->al_lock); |
922 | if (device->resync_locked > device->resync->nr_elements/2) { |
923 | spin_unlock_irq(&device->al_lock); |
924 | return NULL; |
925 | } |
926 | e = lc_get(device->resync, enr); |
927 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
928 | if (bm_ext) { |
929 | if (bm_ext->lce.lc_number != enr) { |
930 | bm_ext->rs_left = drbd_bm_e_weight(device, enr); |
931 | bm_ext->rs_failed = 0; |
932 | lc_committed(device->resync); |
933 | wakeup = 1; |
934 | } |
935 | if (bm_ext->lce.refcnt == 1) |
936 | device->resync_locked++; |
937 | set_bit(BME_NO_WRITES, &bm_ext->flags); |
938 | } |
939 | rs_flags = device->resync->flags; |
940 | spin_unlock_irq(&device->al_lock); |
941 | if (wakeup) |
942 | wake_up(&device->al_wait); |
943 | |
944 | if (!bm_ext) { |
945 | if (rs_flags & LC_STARVING) |
946 | drbd_warn(device, "Have to wait for element" |
947 | " (resync LRU too small?)\n" ); |
948 | BUG_ON(rs_flags & LC_LOCKED); |
949 | } |
950 | |
951 | return bm_ext; |
952 | } |
953 | |
954 | static int _is_in_al(struct drbd_device *device, unsigned int enr) |
955 | { |
956 | int rv; |
957 | |
958 | spin_lock_irq(&device->al_lock); |
959 | rv = lc_is_used(device->act_log, enr); |
960 | spin_unlock_irq(&device->al_lock); |
961 | |
962 | return rv; |
963 | } |
964 | |
965 | /** |
966 | * drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED |
967 | * @device: DRBD device. |
968 | * @sector: The sector number. |
969 | * |
970 | * This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted. |
971 | */ |
972 | int drbd_rs_begin_io(struct drbd_device *device, sector_t sector) |
973 | { |
974 | unsigned int enr = BM_SECT_TO_EXT(sector); |
975 | struct bm_extent *bm_ext; |
976 | int i, sig; |
977 | bool sa; |
978 | |
979 | retry: |
980 | sig = wait_event_interruptible(device->al_wait, |
981 | (bm_ext = _bme_get(device, enr))); |
982 | if (sig) |
983 | return -EINTR; |
984 | |
985 | if (test_bit(BME_LOCKED, &bm_ext->flags)) |
986 | return 0; |
987 | |
988 | /* step aside only while we are above c-min-rate; unless disabled. */ |
989 | sa = drbd_rs_c_min_rate_throttle(device); |
990 | |
991 | for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { |
992 | sig = wait_event_interruptible(device->al_wait, |
993 | !_is_in_al(device, enr * AL_EXT_PER_BM_SECT + i) || |
994 | (sa && test_bit(BME_PRIORITY, &bm_ext->flags))); |
995 | |
996 | if (sig || (sa && test_bit(BME_PRIORITY, &bm_ext->flags))) { |
997 | spin_lock_irq(&device->al_lock); |
998 | if (lc_put(device->resync, &bm_ext->lce) == 0) { |
999 | bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */ |
1000 | device->resync_locked--; |
1001 | wake_up(&device->al_wait); |
1002 | } |
1003 | spin_unlock_irq(&device->al_lock); |
1004 | if (sig) |
1005 | return -EINTR; |
1006 | if (schedule_timeout_interruptible(HZ/10)) |
1007 | return -EINTR; |
1008 | goto retry; |
1009 | } |
1010 | } |
1011 | set_bit(BME_LOCKED, &bm_ext->flags); |
1012 | return 0; |
1013 | } |
1014 | |
1015 | /** |
1016 | * drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep |
1017 | * @device: DRBD device. |
1018 | * @sector: The sector number. |
1019 | * |
1020 | * Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then |
1021 | * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN |
1022 | * if there is still application IO going on in this area. |
1023 | */ |
1024 | int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector) |
1025 | { |
1026 | unsigned int enr = BM_SECT_TO_EXT(sector); |
1027 | const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT; |
1028 | struct lc_element *e; |
1029 | struct bm_extent *bm_ext; |
1030 | int i; |
1031 | bool throttle = drbd_rs_should_slow_down(device, sector, true); |
1032 | |
1033 | /* If we need to throttle, a half-locked (only marked BME_NO_WRITES, |
1034 | * not yet BME_LOCKED) extent needs to be kicked out explicitly if we |
1035 | * need to throttle. There is at most one such half-locked extent, |
1036 | * which is remembered in resync_wenr. */ |
1037 | |
1038 | if (throttle && device->resync_wenr != enr) |
1039 | return -EAGAIN; |
1040 | |
1041 | spin_lock_irq(&device->al_lock); |
1042 | if (device->resync_wenr != LC_FREE && device->resync_wenr != enr) { |
1043 | /* in case you have very heavy scattered io, it may |
1044 | * stall the syncer undefined if we give up the ref count |
1045 | * when we try again and requeue. |
1046 | * |
1047 | * if we don't give up the refcount, but the next time |
1048 | * we are scheduled this extent has been "synced" by new |
1049 | * application writes, we'd miss the lc_put on the |
1050 | * extent we keep the refcount on. |
1051 | * so we remembered which extent we had to try again, and |
1052 | * if the next requested one is something else, we do |
1053 | * the lc_put here... |
1054 | * we also have to wake_up |
1055 | */ |
1056 | e = lc_find(device->resync, device->resync_wenr); |
1057 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1058 | if (bm_ext) { |
1059 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1060 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); |
1061 | clear_bit(BME_NO_WRITES, &bm_ext->flags); |
1062 | device->resync_wenr = LC_FREE; |
1063 | if (lc_put(device->resync, &bm_ext->lce) == 0) { |
1064 | bm_ext->flags = 0; |
1065 | device->resync_locked--; |
1066 | } |
1067 | wake_up(&device->al_wait); |
1068 | } else { |
1069 | drbd_alert(device, "LOGIC BUG\n" ); |
1070 | } |
1071 | } |
1072 | /* TRY. */ |
1073 | e = lc_try_get(device->resync, enr); |
1074 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1075 | if (bm_ext) { |
1076 | if (test_bit(BME_LOCKED, &bm_ext->flags)) |
1077 | goto proceed; |
1078 | if (!test_and_set_bit(BME_NO_WRITES, &bm_ext->flags)) { |
1079 | device->resync_locked++; |
1080 | } else { |
1081 | /* we did set the BME_NO_WRITES, |
1082 | * but then could not set BME_LOCKED, |
1083 | * so we tried again. |
1084 | * drop the extra reference. */ |
1085 | bm_ext->lce.refcnt--; |
1086 | D_ASSERT(device, bm_ext->lce.refcnt > 0); |
1087 | } |
1088 | goto check_al; |
1089 | } else { |
1090 | /* do we rather want to try later? */ |
1091 | if (device->resync_locked > device->resync->nr_elements-3) |
1092 | goto try_again; |
1093 | /* Do or do not. There is no try. -- Yoda */ |
1094 | e = lc_get(device->resync, enr); |
1095 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1096 | if (!bm_ext) { |
1097 | const unsigned long rs_flags = device->resync->flags; |
1098 | if (rs_flags & LC_STARVING) |
1099 | drbd_warn(device, "Have to wait for element" |
1100 | " (resync LRU too small?)\n" ); |
1101 | BUG_ON(rs_flags & LC_LOCKED); |
1102 | goto try_again; |
1103 | } |
1104 | if (bm_ext->lce.lc_number != enr) { |
1105 | bm_ext->rs_left = drbd_bm_e_weight(device, enr); |
1106 | bm_ext->rs_failed = 0; |
1107 | lc_committed(device->resync); |
1108 | wake_up(&device->al_wait); |
1109 | D_ASSERT(device, test_bit(BME_LOCKED, &bm_ext->flags) == 0); |
1110 | } |
1111 | set_bit(BME_NO_WRITES, &bm_ext->flags); |
1112 | D_ASSERT(device, bm_ext->lce.refcnt == 1); |
1113 | device->resync_locked++; |
1114 | goto check_al; |
1115 | } |
1116 | check_al: |
1117 | for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { |
1118 | if (lc_is_used(device->act_log, al_enr+i)) |
1119 | goto try_again; |
1120 | } |
1121 | set_bit(BME_LOCKED, &bm_ext->flags); |
1122 | proceed: |
1123 | device->resync_wenr = LC_FREE; |
1124 | spin_unlock_irq(&device->al_lock); |
1125 | return 0; |
1126 | |
1127 | try_again: |
1128 | if (bm_ext) { |
1129 | if (throttle) { |
1130 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1131 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); |
1132 | clear_bit(BME_NO_WRITES, &bm_ext->flags); |
1133 | device->resync_wenr = LC_FREE; |
1134 | if (lc_put(device->resync, &bm_ext->lce) == 0) { |
1135 | bm_ext->flags = 0; |
1136 | device->resync_locked--; |
1137 | } |
1138 | wake_up(&device->al_wait); |
1139 | } else |
1140 | device->resync_wenr = enr; |
1141 | } |
1142 | spin_unlock_irq(&device->al_lock); |
1143 | return -EAGAIN; |
1144 | } |
1145 | |
1146 | void drbd_rs_complete_io(struct drbd_device *device, sector_t sector) |
1147 | { |
1148 | unsigned int enr = BM_SECT_TO_EXT(sector); |
1149 | struct lc_element *e; |
1150 | struct bm_extent *bm_ext; |
1151 | unsigned long flags; |
1152 | |
1153 | spin_lock_irqsave(&device->al_lock, flags); |
1154 | e = lc_find(device->resync, enr); |
1155 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1156 | if (!bm_ext) { |
1157 | spin_unlock_irqrestore(&device->al_lock, flags); |
1158 | if (__ratelimit(&drbd_ratelimit_state)) |
1159 | drbd_err(device, "drbd_rs_complete_io() called, but extent not found\n" ); |
1160 | return; |
1161 | } |
1162 | |
1163 | if (bm_ext->lce.refcnt == 0) { |
1164 | spin_unlock_irqrestore(&device->al_lock, flags); |
1165 | drbd_err(device, "drbd_rs_complete_io(,%llu [=%u]) called, " |
1166 | "but refcnt is 0!?\n" , |
1167 | (unsigned long long)sector, enr); |
1168 | return; |
1169 | } |
1170 | |
1171 | if (lc_put(device->resync, &bm_ext->lce) == 0) { |
1172 | bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */ |
1173 | device->resync_locked--; |
1174 | wake_up(&device->al_wait); |
1175 | } |
1176 | |
1177 | spin_unlock_irqrestore(&device->al_lock, flags); |
1178 | } |
1179 | |
1180 | /** |
1181 | * drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED) |
1182 | * @device: DRBD device. |
1183 | */ |
1184 | void drbd_rs_cancel_all(struct drbd_device *device) |
1185 | { |
1186 | spin_lock_irq(&device->al_lock); |
1187 | |
1188 | if (get_ldev_if_state(device, D_FAILED)) { /* Makes sure ->resync is there. */ |
1189 | lc_reset(device->resync); |
1190 | put_ldev(device); |
1191 | } |
1192 | device->resync_locked = 0; |
1193 | device->resync_wenr = LC_FREE; |
1194 | spin_unlock_irq(&device->al_lock); |
1195 | wake_up(&device->al_wait); |
1196 | } |
1197 | |
1198 | /** |
1199 | * drbd_rs_del_all() - Gracefully remove all extents from the resync LRU |
1200 | * @device: DRBD device. |
1201 | * |
1202 | * Returns 0 upon success, -EAGAIN if at least one reference count was |
1203 | * not zero. |
1204 | */ |
1205 | int drbd_rs_del_all(struct drbd_device *device) |
1206 | { |
1207 | struct lc_element *e; |
1208 | struct bm_extent *bm_ext; |
1209 | int i; |
1210 | |
1211 | spin_lock_irq(&device->al_lock); |
1212 | |
1213 | if (get_ldev_if_state(device, D_FAILED)) { |
1214 | /* ok, ->resync is there. */ |
1215 | for (i = 0; i < device->resync->nr_elements; i++) { |
1216 | e = lc_element_by_index(device->resync, i); |
1217 | bm_ext = lc_entry(e, struct bm_extent, lce); |
1218 | if (bm_ext->lce.lc_number == LC_FREE) |
1219 | continue; |
1220 | if (bm_ext->lce.lc_number == device->resync_wenr) { |
1221 | drbd_info(device, "dropping %u in drbd_rs_del_all, apparently" |
1222 | " got 'synced' by application io\n" , |
1223 | device->resync_wenr); |
1224 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1225 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); |
1226 | clear_bit(BME_NO_WRITES, &bm_ext->flags); |
1227 | device->resync_wenr = LC_FREE; |
1228 | lc_put(device->resync, &bm_ext->lce); |
1229 | } |
1230 | if (bm_ext->lce.refcnt != 0) { |
1231 | drbd_info(device, "Retrying drbd_rs_del_all() later. " |
1232 | "refcnt=%d\n" , bm_ext->lce.refcnt); |
1233 | put_ldev(device); |
1234 | spin_unlock_irq(&device->al_lock); |
1235 | return -EAGAIN; |
1236 | } |
1237 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1238 | D_ASSERT(device, !test_bit(BME_NO_WRITES, &bm_ext->flags)); |
1239 | lc_del(device->resync, &bm_ext->lce); |
1240 | } |
1241 | D_ASSERT(device, device->resync->used == 0); |
1242 | put_ldev(device); |
1243 | } |
1244 | spin_unlock_irq(&device->al_lock); |
1245 | wake_up(&device->al_wait); |
1246 | |
1247 | return 0; |
1248 | } |
1249 | |