1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | drbd_actlog.c |
4 | |
5 | This file is part of DRBD by Philipp Reisner and Lars Ellenberg. |
6 | |
7 | Copyright (C) 2003-2008, LINBIT Information Technologies GmbH. |
8 | Copyright (C) 2003-2008, Philipp Reisner <philipp.reisner@linbit.com>. |
9 | Copyright (C) 2003-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. |
10 | |
11 | |
12 | */ |
13 | |
14 | #include <linux/slab.h> |
15 | #include <linux/crc32c.h> |
16 | #include <linux/drbd.h> |
17 | #include <linux/drbd_limits.h> |
18 | #include "drbd_int.h" |
19 | |
20 | |
21 | enum al_transaction_types { |
22 | AL_TR_UPDATE = 0, |
23 | AL_TR_INITIALIZED = 0xffff |
24 | }; |
25 | /* all fields on disc in big endian */ |
26 | struct __packed al_transaction_on_disk { |
27 | /* don't we all like magic */ |
28 | __be32 magic; |
29 | |
30 | /* to identify the most recent transaction block |
31 | * in the on disk ring buffer */ |
32 | __be32 tr_number; |
33 | |
34 | /* checksum on the full 4k block, with this field set to 0. */ |
35 | __be32 crc32c; |
36 | |
37 | /* type of transaction, special transaction types like: |
38 | * purge-all, set-all-idle, set-all-active, ... to-be-defined |
39 | * see also enum al_transaction_types */ |
40 | __be16 transaction_type; |
41 | |
42 | /* we currently allow only a few thousand extents, |
43 | * so 16bit will be enough for the slot number. */ |
44 | |
45 | /* how many updates in this transaction */ |
46 | __be16 n_updates; |
47 | |
48 | /* maximum slot number, "al-extents" in drbd.conf speak. |
49 | * Having this in each transaction should make reconfiguration |
50 | * of that parameter easier. */ |
51 | __be16 context_size; |
52 | |
53 | /* slot number the context starts with */ |
54 | __be16 context_start_slot_nr; |
55 | |
56 | /* Some reserved bytes. Expected usage is a 64bit counter of |
57 | * sectors-written since device creation, and other data generation tag |
58 | * supporting usage */ |
59 | __be32 __reserved[4]; |
60 | |
61 | /* --- 36 byte used --- */ |
62 | |
63 | /* Reserve space for up to AL_UPDATES_PER_TRANSACTION changes |
64 | * in one transaction, then use the remaining byte in the 4k block for |
65 | * context information. "Flexible" number of updates per transaction |
66 | * does not help, as we have to account for the case when all update |
67 | * slots are used anyways, so it would only complicate code without |
68 | * additional benefit. |
69 | */ |
70 | __be16 update_slot_nr[AL_UPDATES_PER_TRANSACTION]; |
71 | |
72 | /* but the extent number is 32bit, which at an extent size of 4 MiB |
73 | * allows to cover device sizes of up to 2**54 Byte (16 PiB) */ |
74 | __be32 update_extent_nr[AL_UPDATES_PER_TRANSACTION]; |
75 | |
76 | /* --- 420 bytes used (36 + 64*6) --- */ |
77 | |
78 | /* 4096 - 420 = 3676 = 919 * 4 */ |
79 | __be32 context[AL_CONTEXT_PER_TRANSACTION]; |
80 | }; |
81 | |
82 | void *drbd_md_get_buffer(struct drbd_device *device, const char *intent) |
83 | { |
84 | int r; |
85 | |
86 | wait_event(device->misc_wait, |
87 | (r = atomic_cmpxchg(&device->md_io.in_use, 0, 1)) == 0 || |
88 | device->state.disk <= D_FAILED); |
89 | |
90 | if (r) |
91 | return NULL; |
92 | |
93 | device->md_io.current_use = intent; |
94 | device->md_io.start_jif = jiffies; |
95 | device->md_io.submit_jif = device->md_io.start_jif - 1; |
96 | return page_address(device->md_io.page); |
97 | } |
98 | |
99 | void drbd_md_put_buffer(struct drbd_device *device) |
100 | { |
101 | if (atomic_dec_and_test(v: &device->md_io.in_use)) |
102 | wake_up(&device->misc_wait); |
103 | } |
104 | |
105 | void wait_until_done_or_force_detached(struct drbd_device *device, struct drbd_backing_dev *bdev, |
106 | unsigned int *done) |
107 | { |
108 | long dt; |
109 | |
110 | rcu_read_lock(); |
111 | dt = rcu_dereference(bdev->disk_conf)->disk_timeout; |
112 | rcu_read_unlock(); |
113 | dt = dt * HZ / 10; |
114 | if (dt == 0) |
115 | dt = MAX_SCHEDULE_TIMEOUT; |
116 | |
117 | dt = wait_event_timeout(device->misc_wait, |
118 | *done || test_bit(FORCE_DETACH, &device->flags), dt); |
119 | if (dt == 0) { |
120 | drbd_err(device, "meta-data IO operation timed out\n" ); |
121 | drbd_chk_io_error(device, 1, DRBD_FORCE_DETACH); |
122 | } |
123 | } |
124 | |
125 | static int _drbd_md_sync_page_io(struct drbd_device *device, |
126 | struct drbd_backing_dev *bdev, |
127 | sector_t sector, enum req_op op) |
128 | { |
129 | struct bio *bio; |
130 | /* we do all our meta data IO in aligned 4k blocks. */ |
131 | const int size = 4096; |
132 | int err; |
133 | blk_opf_t op_flags = 0; |
134 | |
135 | device->md_io.done = 0; |
136 | device->md_io.error = -ENODEV; |
137 | |
138 | if ((op == REQ_OP_WRITE) && !test_bit(MD_NO_FUA, &device->flags)) |
139 | op_flags |= REQ_FUA | REQ_PREFLUSH; |
140 | op_flags |= REQ_SYNC; |
141 | |
142 | bio = bio_alloc_bioset(bdev: bdev->md_bdev, nr_vecs: 1, opf: op | op_flags, GFP_NOIO, |
143 | bs: &drbd_md_io_bio_set); |
144 | bio->bi_iter.bi_sector = sector; |
145 | err = -EIO; |
146 | if (bio_add_page(bio, page: device->md_io.page, len: size, off: 0) != size) |
147 | goto out; |
148 | bio->bi_private = device; |
149 | bio->bi_end_io = drbd_md_endio; |
150 | |
151 | if (op != REQ_OP_WRITE && device->state.disk == D_DISKLESS && device->ldev == NULL) |
152 | /* special case, drbd_md_read() during drbd_adm_attach(): no get_ldev */ |
153 | ; |
154 | else if (!get_ldev_if_state(device, D_ATTACHING)) { |
155 | /* Corresponding put_ldev in drbd_md_endio() */ |
156 | drbd_err(device, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n" ); |
157 | err = -ENODEV; |
158 | goto out; |
159 | } |
160 | |
161 | bio_get(bio); /* one bio_put() is in the completion handler */ |
162 | atomic_inc(v: &device->md_io.in_use); /* drbd_md_put_buffer() is in the completion handler */ |
163 | device->md_io.submit_jif = jiffies; |
164 | if (drbd_insert_fault(device, type: (op == REQ_OP_WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) |
165 | bio_io_error(bio); |
166 | else |
167 | submit_bio(bio); |
168 | wait_until_done_or_force_detached(device, bdev, done: &device->md_io.done); |
169 | if (!bio->bi_status) |
170 | err = device->md_io.error; |
171 | |
172 | out: |
173 | bio_put(bio); |
174 | return err; |
175 | } |
176 | |
177 | int drbd_md_sync_page_io(struct drbd_device *device, struct drbd_backing_dev *bdev, |
178 | sector_t sector, enum req_op op) |
179 | { |
180 | int err; |
181 | D_ASSERT(device, atomic_read(&device->md_io.in_use) == 1); |
182 | |
183 | BUG_ON(!bdev->md_bdev); |
184 | |
185 | dynamic_drbd_dbg(device, "meta_data io: %s [%d]:%s(,%llus,%s) %pS\n" , |
186 | current->comm, current->pid, __func__, |
187 | (unsigned long long)sector, (op == REQ_OP_WRITE) ? "WRITE" : "READ" , |
188 | (void*)_RET_IP_ ); |
189 | |
190 | if (sector < drbd_md_first_sector(bdev) || |
191 | sector + 7 > drbd_md_last_sector(bdev)) |
192 | drbd_alert(device, "%s [%d]:%s(,%llus,%s) out of range md access!\n" , |
193 | current->comm, current->pid, __func__, |
194 | (unsigned long long)sector, |
195 | (op == REQ_OP_WRITE) ? "WRITE" : "READ" ); |
196 | |
197 | err = _drbd_md_sync_page_io(device, bdev, sector, op); |
198 | if (err) { |
199 | drbd_err(device, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n" , |
200 | (unsigned long long)sector, |
201 | (op == REQ_OP_WRITE) ? "WRITE" : "READ" , err); |
202 | } |
203 | return err; |
204 | } |
205 | |
206 | static struct bm_extent *find_active_resync_extent(struct drbd_device *device, unsigned int enr) |
207 | { |
208 | struct lc_element *tmp; |
209 | tmp = lc_find(lc: device->resync, enr: enr/AL_EXT_PER_BM_SECT); |
210 | if (unlikely(tmp != NULL)) { |
211 | struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); |
212 | if (test_bit(BME_NO_WRITES, &bm_ext->flags)) |
213 | return bm_ext; |
214 | } |
215 | return NULL; |
216 | } |
217 | |
218 | static struct lc_element *_al_get(struct drbd_device *device, unsigned int enr, bool nonblock) |
219 | { |
220 | struct lc_element *al_ext; |
221 | struct bm_extent *bm_ext; |
222 | int wake; |
223 | |
224 | spin_lock_irq(lock: &device->al_lock); |
225 | bm_ext = find_active_resync_extent(device, enr); |
226 | if (bm_ext) { |
227 | wake = !test_and_set_bit(BME_PRIORITY, addr: &bm_ext->flags); |
228 | spin_unlock_irq(lock: &device->al_lock); |
229 | if (wake) |
230 | wake_up(&device->al_wait); |
231 | return NULL; |
232 | } |
233 | if (nonblock) |
234 | al_ext = lc_try_get(lc: device->act_log, enr); |
235 | else |
236 | al_ext = lc_get(lc: device->act_log, enr); |
237 | spin_unlock_irq(lock: &device->al_lock); |
238 | return al_ext; |
239 | } |
240 | |
241 | bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i) |
242 | { |
243 | /* for bios crossing activity log extent boundaries, |
244 | * we may need to activate two extents in one go */ |
245 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
246 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
247 | |
248 | D_ASSERT(device, first <= last); |
249 | D_ASSERT(device, atomic_read(&device->local_cnt) > 0); |
250 | |
251 | /* FIXME figure out a fast path for bios crossing AL extent boundaries */ |
252 | if (first != last) |
253 | return false; |
254 | |
255 | return _al_get(device, enr: first, nonblock: true); |
256 | } |
257 | |
258 | bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i) |
259 | { |
260 | /* for bios crossing activity log extent boundaries, |
261 | * we may need to activate two extents in one go */ |
262 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
263 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
264 | unsigned enr; |
265 | bool need_transaction = false; |
266 | |
267 | D_ASSERT(device, first <= last); |
268 | D_ASSERT(device, atomic_read(&device->local_cnt) > 0); |
269 | |
270 | for (enr = first; enr <= last; enr++) { |
271 | struct lc_element *al_ext; |
272 | wait_event(device->al_wait, |
273 | (al_ext = _al_get(device, enr, false)) != NULL); |
274 | if (al_ext->lc_number != enr) |
275 | need_transaction = true; |
276 | } |
277 | return need_transaction; |
278 | } |
279 | |
280 | #if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT) |
281 | /* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT |
282 | * are still coupled, or assume too much about their relation. |
283 | * Code below will not work if this is violated. |
284 | * Will be cleaned up with some followup patch. |
285 | */ |
286 | # error FIXME |
287 | #endif |
288 | |
289 | static unsigned int al_extent_to_bm_page(unsigned int al_enr) |
290 | { |
291 | return al_enr >> |
292 | /* bit to page */ |
293 | ((PAGE_SHIFT + 3) - |
294 | /* al extent number to bit */ |
295 | (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)); |
296 | } |
297 | |
298 | static sector_t al_tr_number_to_on_disk_sector(struct drbd_device *device) |
299 | { |
300 | const unsigned int stripes = device->ldev->md.al_stripes; |
301 | const unsigned int stripe_size_4kB = device->ldev->md.al_stripe_size_4k; |
302 | |
303 | /* transaction number, modulo on-disk ring buffer wrap around */ |
304 | unsigned int t = device->al_tr_number % (device->ldev->md.al_size_4k); |
305 | |
306 | /* ... to aligned 4k on disk block */ |
307 | t = ((t % stripes) * stripe_size_4kB) + t/stripes; |
308 | |
309 | /* ... to 512 byte sector in activity log */ |
310 | t *= 8; |
311 | |
312 | /* ... plus offset to the on disk position */ |
313 | return device->ldev->md.md_offset + device->ldev->md.al_offset + t; |
314 | } |
315 | |
316 | static int __al_write_transaction(struct drbd_device *device, struct al_transaction_on_disk *buffer) |
317 | { |
318 | struct lc_element *e; |
319 | sector_t sector; |
320 | int i, mx; |
321 | unsigned extent_nr; |
322 | unsigned crc = 0; |
323 | int err = 0; |
324 | |
325 | memset(buffer, 0, sizeof(*buffer)); |
326 | buffer->magic = cpu_to_be32(DRBD_AL_MAGIC); |
327 | buffer->tr_number = cpu_to_be32(device->al_tr_number); |
328 | |
329 | i = 0; |
330 | |
331 | drbd_bm_reset_al_hints(device); |
332 | |
333 | /* Even though no one can start to change this list |
334 | * once we set the LC_LOCKED -- from drbd_al_begin_io(), |
335 | * lc_try_lock_for_transaction() --, someone may still |
336 | * be in the process of changing it. */ |
337 | spin_lock_irq(lock: &device->al_lock); |
338 | list_for_each_entry(e, &device->act_log->to_be_changed, list) { |
339 | if (i == AL_UPDATES_PER_TRANSACTION) { |
340 | i++; |
341 | break; |
342 | } |
343 | buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index); |
344 | buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number); |
345 | if (e->lc_number != LC_FREE) |
346 | drbd_bm_mark_for_writeout(device, |
347 | page_nr: al_extent_to_bm_page(al_enr: e->lc_number)); |
348 | i++; |
349 | } |
350 | spin_unlock_irq(lock: &device->al_lock); |
351 | BUG_ON(i > AL_UPDATES_PER_TRANSACTION); |
352 | |
353 | buffer->n_updates = cpu_to_be16(i); |
354 | for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) { |
355 | buffer->update_slot_nr[i] = cpu_to_be16(-1); |
356 | buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE); |
357 | } |
358 | |
359 | buffer->context_size = cpu_to_be16(device->act_log->nr_elements); |
360 | buffer->context_start_slot_nr = cpu_to_be16(device->al_tr_cycle); |
361 | |
362 | mx = min_t(int, AL_CONTEXT_PER_TRANSACTION, |
363 | device->act_log->nr_elements - device->al_tr_cycle); |
364 | for (i = 0; i < mx; i++) { |
365 | unsigned idx = device->al_tr_cycle + i; |
366 | extent_nr = lc_element_by_index(lc: device->act_log, i: idx)->lc_number; |
367 | buffer->context[i] = cpu_to_be32(extent_nr); |
368 | } |
369 | for (; i < AL_CONTEXT_PER_TRANSACTION; i++) |
370 | buffer->context[i] = cpu_to_be32(LC_FREE); |
371 | |
372 | device->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION; |
373 | if (device->al_tr_cycle >= device->act_log->nr_elements) |
374 | device->al_tr_cycle = 0; |
375 | |
376 | sector = al_tr_number_to_on_disk_sector(device); |
377 | |
378 | crc = crc32c(crc: 0, address: buffer, length: 4096); |
379 | buffer->crc32c = cpu_to_be32(crc); |
380 | |
381 | if (drbd_bm_write_hinted(device)) |
382 | err = -EIO; |
383 | else { |
384 | bool write_al_updates; |
385 | rcu_read_lock(); |
386 | write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates; |
387 | rcu_read_unlock(); |
388 | if (write_al_updates) { |
389 | if (drbd_md_sync_page_io(device, bdev: device->ldev, sector, op: REQ_OP_WRITE)) { |
390 | err = -EIO; |
391 | drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR); |
392 | } else { |
393 | device->al_tr_number++; |
394 | device->al_writ_cnt++; |
395 | } |
396 | } |
397 | } |
398 | |
399 | return err; |
400 | } |
401 | |
402 | static int al_write_transaction(struct drbd_device *device) |
403 | { |
404 | struct al_transaction_on_disk *buffer; |
405 | int err; |
406 | |
407 | if (!get_ldev(device)) { |
408 | drbd_err(device, "disk is %s, cannot start al transaction\n" , |
409 | drbd_disk_str(device->state.disk)); |
410 | return -EIO; |
411 | } |
412 | |
413 | /* The bitmap write may have failed, causing a state change. */ |
414 | if (device->state.disk < D_INCONSISTENT) { |
415 | drbd_err(device, |
416 | "disk is %s, cannot write al transaction\n" , |
417 | drbd_disk_str(device->state.disk)); |
418 | put_ldev(device); |
419 | return -EIO; |
420 | } |
421 | |
422 | /* protects md_io_buffer, al_tr_cycle, ... */ |
423 | buffer = drbd_md_get_buffer(device, intent: __func__); |
424 | if (!buffer) { |
425 | drbd_err(device, "disk failed while waiting for md_io buffer\n" ); |
426 | put_ldev(device); |
427 | return -ENODEV; |
428 | } |
429 | |
430 | err = __al_write_transaction(device, buffer); |
431 | |
432 | drbd_md_put_buffer(device); |
433 | put_ldev(device); |
434 | |
435 | return err; |
436 | } |
437 | |
438 | |
439 | void drbd_al_begin_io_commit(struct drbd_device *device) |
440 | { |
441 | bool locked = false; |
442 | |
443 | /* Serialize multiple transactions. |
444 | * This uses test_and_set_bit, memory barrier is implicit. |
445 | */ |
446 | wait_event(device->al_wait, |
447 | device->act_log->pending_changes == 0 || |
448 | (locked = lc_try_lock_for_transaction(device->act_log))); |
449 | |
450 | if (locked) { |
451 | /* Double check: it may have been committed by someone else, |
452 | * while we have been waiting for the lock. */ |
453 | if (device->act_log->pending_changes) { |
454 | bool write_al_updates; |
455 | |
456 | rcu_read_lock(); |
457 | write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates; |
458 | rcu_read_unlock(); |
459 | |
460 | if (write_al_updates) |
461 | al_write_transaction(device); |
462 | spin_lock_irq(lock: &device->al_lock); |
463 | /* FIXME |
464 | if (err) |
465 | we need an "lc_cancel" here; |
466 | */ |
467 | lc_committed(lc: device->act_log); |
468 | spin_unlock_irq(lock: &device->al_lock); |
469 | } |
470 | lc_unlock(lc: device->act_log); |
471 | wake_up(&device->al_wait); |
472 | } |
473 | } |
474 | |
475 | /* |
476 | * @delegate: delegate activity log I/O to the worker thread |
477 | */ |
478 | void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i) |
479 | { |
480 | if (drbd_al_begin_io_prepare(device, i)) |
481 | drbd_al_begin_io_commit(device); |
482 | } |
483 | |
484 | int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i) |
485 | { |
486 | struct lru_cache *al = device->act_log; |
487 | /* for bios crossing activity log extent boundaries, |
488 | * we may need to activate two extents in one go */ |
489 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
490 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
491 | unsigned nr_al_extents; |
492 | unsigned available_update_slots; |
493 | unsigned enr; |
494 | |
495 | D_ASSERT(device, first <= last); |
496 | |
497 | nr_al_extents = 1 + last - first; /* worst case: all touched extends are cold. */ |
498 | available_update_slots = min(al->nr_elements - al->used, |
499 | al->max_pending_changes - al->pending_changes); |
500 | |
501 | /* We want all necessary updates for a given request within the same transaction |
502 | * We could first check how many updates are *actually* needed, |
503 | * and use that instead of the worst-case nr_al_extents */ |
504 | if (available_update_slots < nr_al_extents) { |
505 | /* Too many activity log extents are currently "hot". |
506 | * |
507 | * If we have accumulated pending changes already, |
508 | * we made progress. |
509 | * |
510 | * If we cannot get even a single pending change through, |
511 | * stop the fast path until we made some progress, |
512 | * or requests to "cold" extents could be starved. */ |
513 | if (!al->pending_changes) |
514 | __set_bit(__LC_STARVING, &device->act_log->flags); |
515 | return -ENOBUFS; |
516 | } |
517 | |
518 | /* Is resync active in this area? */ |
519 | for (enr = first; enr <= last; enr++) { |
520 | struct lc_element *tmp; |
521 | tmp = lc_find(lc: device->resync, enr: enr/AL_EXT_PER_BM_SECT); |
522 | if (unlikely(tmp != NULL)) { |
523 | struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); |
524 | if (test_bit(BME_NO_WRITES, &bm_ext->flags)) { |
525 | if (!test_and_set_bit(BME_PRIORITY, addr: &bm_ext->flags)) |
526 | return -EBUSY; |
527 | return -EWOULDBLOCK; |
528 | } |
529 | } |
530 | } |
531 | |
532 | /* Checkout the refcounts. |
533 | * Given that we checked for available elements and update slots above, |
534 | * this has to be successful. */ |
535 | for (enr = first; enr <= last; enr++) { |
536 | struct lc_element *al_ext; |
537 | al_ext = lc_get_cumulative(lc: device->act_log, enr); |
538 | if (!al_ext) |
539 | drbd_info(device, "LOGIC BUG for enr=%u\n" , enr); |
540 | } |
541 | return 0; |
542 | } |
543 | |
544 | void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i) |
545 | { |
546 | /* for bios crossing activity log extent boundaries, |
547 | * we may need to activate two extents in one go */ |
548 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
549 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
550 | unsigned enr; |
551 | struct lc_element *extent; |
552 | unsigned long flags; |
553 | |
554 | D_ASSERT(device, first <= last); |
555 | spin_lock_irqsave(&device->al_lock, flags); |
556 | |
557 | for (enr = first; enr <= last; enr++) { |
558 | extent = lc_find(lc: device->act_log, enr); |
559 | if (!extent) { |
560 | drbd_err(device, "al_complete_io() called on inactive extent %u\n" , enr); |
561 | continue; |
562 | } |
563 | lc_put(lc: device->act_log, e: extent); |
564 | } |
565 | spin_unlock_irqrestore(lock: &device->al_lock, flags); |
566 | wake_up(&device->al_wait); |
567 | } |
568 | |
569 | static int _try_lc_del(struct drbd_device *device, struct lc_element *al_ext) |
570 | { |
571 | int rv; |
572 | |
573 | spin_lock_irq(lock: &device->al_lock); |
574 | rv = (al_ext->refcnt == 0); |
575 | if (likely(rv)) |
576 | lc_del(lc: device->act_log, element: al_ext); |
577 | spin_unlock_irq(lock: &device->al_lock); |
578 | |
579 | return rv; |
580 | } |
581 | |
582 | /** |
583 | * drbd_al_shrink() - Removes all active extents form the activity log |
584 | * @device: DRBD device. |
585 | * |
586 | * Removes all active extents form the activity log, waiting until |
587 | * the reference count of each entry dropped to 0 first, of course. |
588 | * |
589 | * You need to lock device->act_log with lc_try_lock() / lc_unlock() |
590 | */ |
591 | void drbd_al_shrink(struct drbd_device *device) |
592 | { |
593 | struct lc_element *al_ext; |
594 | int i; |
595 | |
596 | D_ASSERT(device, test_bit(__LC_LOCKED, &device->act_log->flags)); |
597 | |
598 | for (i = 0; i < device->act_log->nr_elements; i++) { |
599 | al_ext = lc_element_by_index(lc: device->act_log, i); |
600 | if (al_ext->lc_number == LC_FREE) |
601 | continue; |
602 | wait_event(device->al_wait, _try_lc_del(device, al_ext)); |
603 | } |
604 | |
605 | wake_up(&device->al_wait); |
606 | } |
607 | |
608 | int drbd_al_initialize(struct drbd_device *device, void *buffer) |
609 | { |
610 | struct al_transaction_on_disk *al = buffer; |
611 | struct drbd_md *md = &device->ldev->md; |
612 | int al_size_4k = md->al_stripes * md->al_stripe_size_4k; |
613 | int i; |
614 | |
615 | __al_write_transaction(device, buffer: al); |
616 | /* There may or may not have been a pending transaction. */ |
617 | spin_lock_irq(lock: &device->al_lock); |
618 | lc_committed(lc: device->act_log); |
619 | spin_unlock_irq(lock: &device->al_lock); |
620 | |
621 | /* The rest of the transactions will have an empty "updates" list, and |
622 | * are written out only to provide the context, and to initialize the |
623 | * on-disk ring buffer. */ |
624 | for (i = 1; i < al_size_4k; i++) { |
625 | int err = __al_write_transaction(device, buffer: al); |
626 | if (err) |
627 | return err; |
628 | } |
629 | return 0; |
630 | } |
631 | |
632 | static const char *drbd_change_sync_fname[] = { |
633 | [RECORD_RS_FAILED] = "drbd_rs_failed_io" , |
634 | [SET_IN_SYNC] = "drbd_set_in_sync" , |
635 | [SET_OUT_OF_SYNC] = "drbd_set_out_of_sync" |
636 | }; |
637 | |
638 | /* ATTENTION. The AL's extents are 4MB each, while the extents in the |
639 | * resync LRU-cache are 16MB each. |
640 | * The caller of this function has to hold an get_ldev() reference. |
641 | * |
642 | * Adjusts the caching members ->rs_left (success) or ->rs_failed (!success), |
643 | * potentially pulling in (and recounting the corresponding bits) |
644 | * this resync extent into the resync extent lru cache. |
645 | * |
646 | * Returns whether all bits have been cleared for this resync extent, |
647 | * precisely: (rs_left <= rs_failed) |
648 | * |
649 | * TODO will be obsoleted once we have a caching lru of the on disk bitmap |
650 | */ |
651 | static bool update_rs_extent(struct drbd_device *device, |
652 | unsigned int enr, int count, |
653 | enum update_sync_bits_mode mode) |
654 | { |
655 | struct lc_element *e; |
656 | |
657 | D_ASSERT(device, atomic_read(&device->local_cnt)); |
658 | |
659 | /* When setting out-of-sync bits, |
660 | * we don't need it cached (lc_find). |
661 | * But if it is present in the cache, |
662 | * we should update the cached bit count. |
663 | * Otherwise, that extent should be in the resync extent lru cache |
664 | * already -- or we want to pull it in if necessary -- (lc_get), |
665 | * then update and check rs_left and rs_failed. */ |
666 | if (mode == SET_OUT_OF_SYNC) |
667 | e = lc_find(lc: device->resync, enr); |
668 | else |
669 | e = lc_get(lc: device->resync, enr); |
670 | if (e) { |
671 | struct bm_extent *ext = lc_entry(e, struct bm_extent, lce); |
672 | if (ext->lce.lc_number == enr) { |
673 | if (mode == SET_IN_SYNC) |
674 | ext->rs_left -= count; |
675 | else if (mode == SET_OUT_OF_SYNC) |
676 | ext->rs_left += count; |
677 | else |
678 | ext->rs_failed += count; |
679 | if (ext->rs_left < ext->rs_failed) { |
680 | drbd_warn(device, "BAD! enr=%u rs_left=%d " |
681 | "rs_failed=%d count=%d cstate=%s\n" , |
682 | ext->lce.lc_number, ext->rs_left, |
683 | ext->rs_failed, count, |
684 | drbd_conn_str(device->state.conn)); |
685 | |
686 | /* We don't expect to be able to clear more bits |
687 | * than have been set when we originally counted |
688 | * the set bits to cache that value in ext->rs_left. |
689 | * Whatever the reason (disconnect during resync, |
690 | * delayed local completion of an application write), |
691 | * try to fix it up by recounting here. */ |
692 | ext->rs_left = drbd_bm_e_weight(device, enr); |
693 | } |
694 | } else { |
695 | /* Normally this element should be in the cache, |
696 | * since drbd_rs_begin_io() pulled it already in. |
697 | * |
698 | * But maybe an application write finished, and we set |
699 | * something outside the resync lru_cache in sync. |
700 | */ |
701 | int rs_left = drbd_bm_e_weight(device, enr); |
702 | if (ext->flags != 0) { |
703 | drbd_warn(device, "changing resync lce: %d[%u;%02lx]" |
704 | " -> %d[%u;00]\n" , |
705 | ext->lce.lc_number, ext->rs_left, |
706 | ext->flags, enr, rs_left); |
707 | ext->flags = 0; |
708 | } |
709 | if (ext->rs_failed) { |
710 | drbd_warn(device, "Kicking resync_lru element enr=%u " |
711 | "out with rs_failed=%d\n" , |
712 | ext->lce.lc_number, ext->rs_failed); |
713 | } |
714 | ext->rs_left = rs_left; |
715 | ext->rs_failed = (mode == RECORD_RS_FAILED) ? count : 0; |
716 | /* we don't keep a persistent log of the resync lru, |
717 | * we can commit any change right away. */ |
718 | lc_committed(lc: device->resync); |
719 | } |
720 | if (mode != SET_OUT_OF_SYNC) |
721 | lc_put(lc: device->resync, e: &ext->lce); |
722 | /* no race, we are within the al_lock! */ |
723 | |
724 | if (ext->rs_left <= ext->rs_failed) { |
725 | ext->rs_failed = 0; |
726 | return true; |
727 | } |
728 | } else if (mode != SET_OUT_OF_SYNC) { |
729 | /* be quiet if lc_find() did not find it. */ |
730 | drbd_err(device, "lc_get() failed! locked=%d/%d flags=%lu\n" , |
731 | device->resync_locked, |
732 | device->resync->nr_elements, |
733 | device->resync->flags); |
734 | } |
735 | return false; |
736 | } |
737 | |
738 | void drbd_advance_rs_marks(struct drbd_peer_device *peer_device, unsigned long still_to_go) |
739 | { |
740 | struct drbd_device *device = peer_device->device; |
741 | unsigned long now = jiffies; |
742 | unsigned long last = device->rs_mark_time[device->rs_last_mark]; |
743 | int next = (device->rs_last_mark + 1) % DRBD_SYNC_MARKS; |
744 | if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) { |
745 | if (device->rs_mark_left[device->rs_last_mark] != still_to_go && |
746 | device->state.conn != C_PAUSED_SYNC_T && |
747 | device->state.conn != C_PAUSED_SYNC_S) { |
748 | device->rs_mark_time[next] = now; |
749 | device->rs_mark_left[next] = still_to_go; |
750 | device->rs_last_mark = next; |
751 | } |
752 | } |
753 | } |
754 | |
755 | /* It is called lazy update, so don't do write-out too often. */ |
756 | static bool lazy_bitmap_update_due(struct drbd_device *device) |
757 | { |
758 | return time_after(jiffies, device->rs_last_bcast + 2*HZ); |
759 | } |
760 | |
761 | static void maybe_schedule_on_disk_bitmap_update(struct drbd_device *device, bool rs_done) |
762 | { |
763 | if (rs_done) { |
764 | struct drbd_connection *connection = first_peer_device(device)->connection; |
765 | if (connection->agreed_pro_version <= 95 || |
766 | is_sync_target_state(connection_state: device->state.conn)) |
767 | set_bit(nr: RS_DONE, addr: &device->flags); |
768 | /* and also set RS_PROGRESS below */ |
769 | |
770 | /* Else: rather wait for explicit notification via receive_state, |
771 | * to avoid uuids-rotated-too-fast causing full resync |
772 | * in next handshake, in case the replication link breaks |
773 | * at the most unfortunate time... */ |
774 | } else if (!lazy_bitmap_update_due(device)) |
775 | return; |
776 | |
777 | drbd_device_post_work(device, work_bit: RS_PROGRESS); |
778 | } |
779 | |
780 | static int update_sync_bits(struct drbd_device *device, |
781 | unsigned long sbnr, unsigned long ebnr, |
782 | enum update_sync_bits_mode mode) |
783 | { |
784 | /* |
785 | * We keep a count of set bits per resync-extent in the ->rs_left |
786 | * caching member, so we need to loop and work within the resync extent |
787 | * alignment. Typically this loop will execute exactly once. |
788 | */ |
789 | unsigned long flags; |
790 | unsigned long count = 0; |
791 | unsigned int cleared = 0; |
792 | while (sbnr <= ebnr) { |
793 | /* set temporary boundary bit number to last bit number within |
794 | * the resync extent of the current start bit number, |
795 | * but cap at provided end bit number */ |
796 | unsigned long tbnr = min(ebnr, sbnr | BM_BLOCKS_PER_BM_EXT_MASK); |
797 | unsigned long c; |
798 | |
799 | if (mode == RECORD_RS_FAILED) |
800 | /* Only called from drbd_rs_failed_io(), bits |
801 | * supposedly still set. Recount, maybe some |
802 | * of the bits have been successfully cleared |
803 | * by application IO meanwhile. |
804 | */ |
805 | c = drbd_bm_count_bits(device, s: sbnr, e: tbnr); |
806 | else if (mode == SET_IN_SYNC) |
807 | c = drbd_bm_clear_bits(device, s: sbnr, e: tbnr); |
808 | else /* if (mode == SET_OUT_OF_SYNC) */ |
809 | c = drbd_bm_set_bits(device, s: sbnr, e: tbnr); |
810 | |
811 | if (c) { |
812 | spin_lock_irqsave(&device->al_lock, flags); |
813 | cleared += update_rs_extent(device, BM_BIT_TO_EXT(sbnr), count: c, mode); |
814 | spin_unlock_irqrestore(lock: &device->al_lock, flags); |
815 | count += c; |
816 | } |
817 | sbnr = tbnr + 1; |
818 | } |
819 | if (count) { |
820 | if (mode == SET_IN_SYNC) { |
821 | unsigned long still_to_go = drbd_bm_total_weight(device); |
822 | bool rs_is_done = (still_to_go <= device->rs_failed); |
823 | drbd_advance_rs_marks(peer_device: first_peer_device(device), still_to_go); |
824 | if (cleared || rs_is_done) |
825 | maybe_schedule_on_disk_bitmap_update(device, rs_done: rs_is_done); |
826 | } else if (mode == RECORD_RS_FAILED) |
827 | device->rs_failed += count; |
828 | wake_up(&device->al_wait); |
829 | } |
830 | return count; |
831 | } |
832 | |
833 | static bool plausible_request_size(int size) |
834 | { |
835 | return size > 0 |
836 | && size <= DRBD_MAX_BATCH_BIO_SIZE |
837 | && IS_ALIGNED(size, 512); |
838 | } |
839 | |
840 | /* clear the bit corresponding to the piece of storage in question: |
841 | * size byte of data starting from sector. Only clear a bits of the affected |
842 | * one ore more _aligned_ BM_BLOCK_SIZE blocks. |
843 | * |
844 | * called by worker on C_SYNC_TARGET and receiver on SyncSource. |
845 | * |
846 | */ |
847 | int __drbd_change_sync(struct drbd_peer_device *peer_device, sector_t sector, int size, |
848 | enum update_sync_bits_mode mode) |
849 | { |
850 | /* Is called from worker and receiver context _only_ */ |
851 | struct drbd_device *device = peer_device->device; |
852 | unsigned long sbnr, ebnr, lbnr; |
853 | unsigned long count = 0; |
854 | sector_t esector, nr_sectors; |
855 | |
856 | /* This would be an empty REQ_PREFLUSH, be silent. */ |
857 | if ((mode == SET_OUT_OF_SYNC) && size == 0) |
858 | return 0; |
859 | |
860 | if (!plausible_request_size(size)) { |
861 | drbd_err(device, "%s: sector=%llus size=%d nonsense!\n" , |
862 | drbd_change_sync_fname[mode], |
863 | (unsigned long long)sector, size); |
864 | return 0; |
865 | } |
866 | |
867 | if (!get_ldev(device)) |
868 | return 0; /* no disk, no metadata, no bitmap to manipulate bits in */ |
869 | |
870 | nr_sectors = get_capacity(disk: device->vdisk); |
871 | esector = sector + (size >> 9) - 1; |
872 | |
873 | if (!expect(device, sector < nr_sectors)) |
874 | goto out; |
875 | if (!expect(device, esector < nr_sectors)) |
876 | esector = nr_sectors - 1; |
877 | |
878 | lbnr = BM_SECT_TO_BIT(nr_sectors-1); |
879 | |
880 | if (mode == SET_IN_SYNC) { |
881 | /* Round up start sector, round down end sector. We make sure |
882 | * we only clear full, aligned, BM_BLOCK_SIZE blocks. */ |
883 | if (unlikely(esector < BM_SECT_PER_BIT-1)) |
884 | goto out; |
885 | if (unlikely(esector == (nr_sectors-1))) |
886 | ebnr = lbnr; |
887 | else |
888 | ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1)); |
889 | sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1); |
890 | } else { |
891 | /* We set it out of sync, or record resync failure. |
892 | * Should not round anything here. */ |
893 | sbnr = BM_SECT_TO_BIT(sector); |
894 | ebnr = BM_SECT_TO_BIT(esector); |
895 | } |
896 | |
897 | count = update_sync_bits(device, sbnr, ebnr, mode); |
898 | out: |
899 | put_ldev(device); |
900 | return count; |
901 | } |
902 | |
903 | static |
904 | struct bm_extent *_bme_get(struct drbd_device *device, unsigned int enr) |
905 | { |
906 | struct lc_element *e; |
907 | struct bm_extent *bm_ext; |
908 | int wakeup = 0; |
909 | unsigned long rs_flags; |
910 | |
911 | spin_lock_irq(lock: &device->al_lock); |
912 | if (device->resync_locked > device->resync->nr_elements/2) { |
913 | spin_unlock_irq(lock: &device->al_lock); |
914 | return NULL; |
915 | } |
916 | e = lc_get(lc: device->resync, enr); |
917 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
918 | if (bm_ext) { |
919 | if (bm_ext->lce.lc_number != enr) { |
920 | bm_ext->rs_left = drbd_bm_e_weight(device, enr); |
921 | bm_ext->rs_failed = 0; |
922 | lc_committed(lc: device->resync); |
923 | wakeup = 1; |
924 | } |
925 | if (bm_ext->lce.refcnt == 1) |
926 | device->resync_locked++; |
927 | set_bit(BME_NO_WRITES, addr: &bm_ext->flags); |
928 | } |
929 | rs_flags = device->resync->flags; |
930 | spin_unlock_irq(lock: &device->al_lock); |
931 | if (wakeup) |
932 | wake_up(&device->al_wait); |
933 | |
934 | if (!bm_ext) { |
935 | if (rs_flags & LC_STARVING) |
936 | drbd_warn(device, "Have to wait for element" |
937 | " (resync LRU too small?)\n" ); |
938 | BUG_ON(rs_flags & LC_LOCKED); |
939 | } |
940 | |
941 | return bm_ext; |
942 | } |
943 | |
944 | static int _is_in_al(struct drbd_device *device, unsigned int enr) |
945 | { |
946 | int rv; |
947 | |
948 | spin_lock_irq(lock: &device->al_lock); |
949 | rv = lc_is_used(lc: device->act_log, enr); |
950 | spin_unlock_irq(lock: &device->al_lock); |
951 | |
952 | return rv; |
953 | } |
954 | |
955 | /** |
956 | * drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED |
957 | * @device: DRBD device. |
958 | * @sector: The sector number. |
959 | * |
960 | * This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted. |
961 | */ |
962 | int drbd_rs_begin_io(struct drbd_device *device, sector_t sector) |
963 | { |
964 | unsigned int enr = BM_SECT_TO_EXT(sector); |
965 | struct bm_extent *bm_ext; |
966 | int i, sig; |
967 | bool sa; |
968 | |
969 | retry: |
970 | sig = wait_event_interruptible(device->al_wait, |
971 | (bm_ext = _bme_get(device, enr))); |
972 | if (sig) |
973 | return -EINTR; |
974 | |
975 | if (test_bit(BME_LOCKED, &bm_ext->flags)) |
976 | return 0; |
977 | |
978 | /* step aside only while we are above c-min-rate; unless disabled. */ |
979 | sa = drbd_rs_c_min_rate_throttle(device); |
980 | |
981 | for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { |
982 | sig = wait_event_interruptible(device->al_wait, |
983 | !_is_in_al(device, enr * AL_EXT_PER_BM_SECT + i) || |
984 | (sa && test_bit(BME_PRIORITY, &bm_ext->flags))); |
985 | |
986 | if (sig || (sa && test_bit(BME_PRIORITY, &bm_ext->flags))) { |
987 | spin_lock_irq(lock: &device->al_lock); |
988 | if (lc_put(lc: device->resync, e: &bm_ext->lce) == 0) { |
989 | bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */ |
990 | device->resync_locked--; |
991 | wake_up(&device->al_wait); |
992 | } |
993 | spin_unlock_irq(lock: &device->al_lock); |
994 | if (sig) |
995 | return -EINTR; |
996 | if (schedule_timeout_interruptible(HZ/10)) |
997 | return -EINTR; |
998 | goto retry; |
999 | } |
1000 | } |
1001 | set_bit(BME_LOCKED, addr: &bm_ext->flags); |
1002 | return 0; |
1003 | } |
1004 | |
1005 | /** |
1006 | * drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep |
1007 | * @device: DRBD device. |
1008 | * @sector: The sector number. |
1009 | * |
1010 | * Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then |
1011 | * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN |
1012 | * if there is still application IO going on in this area. |
1013 | */ |
1014 | int drbd_try_rs_begin_io(struct drbd_peer_device *peer_device, sector_t sector) |
1015 | { |
1016 | struct drbd_device *device = peer_device->device; |
1017 | unsigned int enr = BM_SECT_TO_EXT(sector); |
1018 | const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT; |
1019 | struct lc_element *e; |
1020 | struct bm_extent *bm_ext; |
1021 | int i; |
1022 | bool throttle = drbd_rs_should_slow_down(peer_device, sector, throttle_if_app_is_waiting: true); |
1023 | |
1024 | /* If we need to throttle, a half-locked (only marked BME_NO_WRITES, |
1025 | * not yet BME_LOCKED) extent needs to be kicked out explicitly if we |
1026 | * need to throttle. There is at most one such half-locked extent, |
1027 | * which is remembered in resync_wenr. */ |
1028 | |
1029 | if (throttle && device->resync_wenr != enr) |
1030 | return -EAGAIN; |
1031 | |
1032 | spin_lock_irq(lock: &device->al_lock); |
1033 | if (device->resync_wenr != LC_FREE && device->resync_wenr != enr) { |
1034 | /* in case you have very heavy scattered io, it may |
1035 | * stall the syncer undefined if we give up the ref count |
1036 | * when we try again and requeue. |
1037 | * |
1038 | * if we don't give up the refcount, but the next time |
1039 | * we are scheduled this extent has been "synced" by new |
1040 | * application writes, we'd miss the lc_put on the |
1041 | * extent we keep the refcount on. |
1042 | * so we remembered which extent we had to try again, and |
1043 | * if the next requested one is something else, we do |
1044 | * the lc_put here... |
1045 | * we also have to wake_up |
1046 | */ |
1047 | e = lc_find(lc: device->resync, enr: device->resync_wenr); |
1048 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1049 | if (bm_ext) { |
1050 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1051 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); |
1052 | clear_bit(BME_NO_WRITES, addr: &bm_ext->flags); |
1053 | device->resync_wenr = LC_FREE; |
1054 | if (lc_put(lc: device->resync, e: &bm_ext->lce) == 0) { |
1055 | bm_ext->flags = 0; |
1056 | device->resync_locked--; |
1057 | } |
1058 | wake_up(&device->al_wait); |
1059 | } else { |
1060 | drbd_alert(device, "LOGIC BUG\n" ); |
1061 | } |
1062 | } |
1063 | /* TRY. */ |
1064 | e = lc_try_get(lc: device->resync, enr); |
1065 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1066 | if (bm_ext) { |
1067 | if (test_bit(BME_LOCKED, &bm_ext->flags)) |
1068 | goto proceed; |
1069 | if (!test_and_set_bit(BME_NO_WRITES, addr: &bm_ext->flags)) { |
1070 | device->resync_locked++; |
1071 | } else { |
1072 | /* we did set the BME_NO_WRITES, |
1073 | * but then could not set BME_LOCKED, |
1074 | * so we tried again. |
1075 | * drop the extra reference. */ |
1076 | bm_ext->lce.refcnt--; |
1077 | D_ASSERT(device, bm_ext->lce.refcnt > 0); |
1078 | } |
1079 | goto check_al; |
1080 | } else { |
1081 | /* do we rather want to try later? */ |
1082 | if (device->resync_locked > device->resync->nr_elements-3) |
1083 | goto try_again; |
1084 | /* Do or do not. There is no try. -- Yoda */ |
1085 | e = lc_get(lc: device->resync, enr); |
1086 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1087 | if (!bm_ext) { |
1088 | const unsigned long rs_flags = device->resync->flags; |
1089 | if (rs_flags & LC_STARVING) |
1090 | drbd_warn(device, "Have to wait for element" |
1091 | " (resync LRU too small?)\n" ); |
1092 | BUG_ON(rs_flags & LC_LOCKED); |
1093 | goto try_again; |
1094 | } |
1095 | if (bm_ext->lce.lc_number != enr) { |
1096 | bm_ext->rs_left = drbd_bm_e_weight(device, enr); |
1097 | bm_ext->rs_failed = 0; |
1098 | lc_committed(lc: device->resync); |
1099 | wake_up(&device->al_wait); |
1100 | D_ASSERT(device, test_bit(BME_LOCKED, &bm_ext->flags) == 0); |
1101 | } |
1102 | set_bit(BME_NO_WRITES, addr: &bm_ext->flags); |
1103 | D_ASSERT(device, bm_ext->lce.refcnt == 1); |
1104 | device->resync_locked++; |
1105 | goto check_al; |
1106 | } |
1107 | check_al: |
1108 | for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { |
1109 | if (lc_is_used(lc: device->act_log, enr: al_enr+i)) |
1110 | goto try_again; |
1111 | } |
1112 | set_bit(BME_LOCKED, addr: &bm_ext->flags); |
1113 | proceed: |
1114 | device->resync_wenr = LC_FREE; |
1115 | spin_unlock_irq(lock: &device->al_lock); |
1116 | return 0; |
1117 | |
1118 | try_again: |
1119 | if (bm_ext) { |
1120 | if (throttle) { |
1121 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1122 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); |
1123 | clear_bit(BME_NO_WRITES, addr: &bm_ext->flags); |
1124 | device->resync_wenr = LC_FREE; |
1125 | if (lc_put(lc: device->resync, e: &bm_ext->lce) == 0) { |
1126 | bm_ext->flags = 0; |
1127 | device->resync_locked--; |
1128 | } |
1129 | wake_up(&device->al_wait); |
1130 | } else |
1131 | device->resync_wenr = enr; |
1132 | } |
1133 | spin_unlock_irq(lock: &device->al_lock); |
1134 | return -EAGAIN; |
1135 | } |
1136 | |
1137 | void drbd_rs_complete_io(struct drbd_device *device, sector_t sector) |
1138 | { |
1139 | unsigned int enr = BM_SECT_TO_EXT(sector); |
1140 | struct lc_element *e; |
1141 | struct bm_extent *bm_ext; |
1142 | unsigned long flags; |
1143 | |
1144 | spin_lock_irqsave(&device->al_lock, flags); |
1145 | e = lc_find(lc: device->resync, enr); |
1146 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1147 | if (!bm_ext) { |
1148 | spin_unlock_irqrestore(lock: &device->al_lock, flags); |
1149 | if (drbd_ratelimit()) |
1150 | drbd_err(device, "drbd_rs_complete_io() called, but extent not found\n" ); |
1151 | return; |
1152 | } |
1153 | |
1154 | if (bm_ext->lce.refcnt == 0) { |
1155 | spin_unlock_irqrestore(lock: &device->al_lock, flags); |
1156 | drbd_err(device, "drbd_rs_complete_io(,%llu [=%u]) called, " |
1157 | "but refcnt is 0!?\n" , |
1158 | (unsigned long long)sector, enr); |
1159 | return; |
1160 | } |
1161 | |
1162 | if (lc_put(lc: device->resync, e: &bm_ext->lce) == 0) { |
1163 | bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */ |
1164 | device->resync_locked--; |
1165 | wake_up(&device->al_wait); |
1166 | } |
1167 | |
1168 | spin_unlock_irqrestore(lock: &device->al_lock, flags); |
1169 | } |
1170 | |
1171 | /** |
1172 | * drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED) |
1173 | * @device: DRBD device. |
1174 | */ |
1175 | void drbd_rs_cancel_all(struct drbd_device *device) |
1176 | { |
1177 | spin_lock_irq(lock: &device->al_lock); |
1178 | |
1179 | if (get_ldev_if_state(device, D_FAILED)) { /* Makes sure ->resync is there. */ |
1180 | lc_reset(lc: device->resync); |
1181 | put_ldev(device); |
1182 | } |
1183 | device->resync_locked = 0; |
1184 | device->resync_wenr = LC_FREE; |
1185 | spin_unlock_irq(lock: &device->al_lock); |
1186 | wake_up(&device->al_wait); |
1187 | } |
1188 | |
1189 | /** |
1190 | * drbd_rs_del_all() - Gracefully remove all extents from the resync LRU |
1191 | * @device: DRBD device. |
1192 | * |
1193 | * Returns 0 upon success, -EAGAIN if at least one reference count was |
1194 | * not zero. |
1195 | */ |
1196 | int drbd_rs_del_all(struct drbd_device *device) |
1197 | { |
1198 | struct lc_element *e; |
1199 | struct bm_extent *bm_ext; |
1200 | int i; |
1201 | |
1202 | spin_lock_irq(lock: &device->al_lock); |
1203 | |
1204 | if (get_ldev_if_state(device, D_FAILED)) { |
1205 | /* ok, ->resync is there. */ |
1206 | for (i = 0; i < device->resync->nr_elements; i++) { |
1207 | e = lc_element_by_index(lc: device->resync, i); |
1208 | bm_ext = lc_entry(e, struct bm_extent, lce); |
1209 | if (bm_ext->lce.lc_number == LC_FREE) |
1210 | continue; |
1211 | if (bm_ext->lce.lc_number == device->resync_wenr) { |
1212 | drbd_info(device, "dropping %u in drbd_rs_del_all, apparently" |
1213 | " got 'synced' by application io\n" , |
1214 | device->resync_wenr); |
1215 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1216 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); |
1217 | clear_bit(BME_NO_WRITES, addr: &bm_ext->flags); |
1218 | device->resync_wenr = LC_FREE; |
1219 | lc_put(lc: device->resync, e: &bm_ext->lce); |
1220 | } |
1221 | if (bm_ext->lce.refcnt != 0) { |
1222 | drbd_info(device, "Retrying drbd_rs_del_all() later. " |
1223 | "refcnt=%d\n" , bm_ext->lce.refcnt); |
1224 | put_ldev(device); |
1225 | spin_unlock_irq(lock: &device->al_lock); |
1226 | return -EAGAIN; |
1227 | } |
1228 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1229 | D_ASSERT(device, !test_bit(BME_NO_WRITES, &bm_ext->flags)); |
1230 | lc_del(lc: device->resync, element: &bm_ext->lce); |
1231 | } |
1232 | D_ASSERT(device, device->resync->used == 0); |
1233 | put_ldev(device); |
1234 | } |
1235 | spin_unlock_irq(lock: &device->al_lock); |
1236 | wake_up(&device->al_wait); |
1237 | |
1238 | return 0; |
1239 | } |
1240 | |