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Commit | Line | Data |
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b411b363 PR |
1 | /* |
2 | drbd_req.c | |
3 | ||
4 | This file is part of DRBD by Philipp Reisner and Lars Ellenberg. | |
5 | ||
6 | Copyright (C) 2001-2008, LINBIT Information Technologies GmbH. | |
7 | Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>. | |
8 | Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. | |
9 | ||
10 | drbd is free software; you can redistribute it and/or modify | |
11 | it under the terms of the GNU General Public License as published by | |
12 | the Free Software Foundation; either version 2, or (at your option) | |
13 | any later version. | |
14 | ||
15 | drbd is distributed in the hope that it will be useful, | |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | GNU General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU General Public License | |
21 | along with drbd; see the file COPYING. If not, write to | |
22 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
23 | ||
24 | */ | |
25 | ||
b411b363 PR |
26 | #include <linux/module.h> |
27 | ||
28 | #include <linux/slab.h> | |
29 | #include <linux/drbd.h> | |
30 | #include "drbd_int.h" | |
b411b363 PR |
31 | #include "drbd_req.h" |
32 | ||
33 | ||
34 | /* Update disk stats at start of I/O request */ | |
35 | static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req, struct bio *bio) | |
36 | { | |
37 | const int rw = bio_data_dir(bio); | |
38 | int cpu; | |
39 | cpu = part_stat_lock(); | |
40 | part_stat_inc(cpu, &mdev->vdisk->part0, ios[rw]); | |
41 | part_stat_add(cpu, &mdev->vdisk->part0, sectors[rw], bio_sectors(bio)); | |
753c8913 | 42 | part_inc_in_flight(&mdev->vdisk->part0, rw); |
b411b363 | 43 | part_stat_unlock(); |
b411b363 PR |
44 | } |
45 | ||
46 | /* Update disk stats when completing request upwards */ | |
47 | static void _drbd_end_io_acct(struct drbd_conf *mdev, struct drbd_request *req) | |
48 | { | |
49 | int rw = bio_data_dir(req->master_bio); | |
50 | unsigned long duration = jiffies - req->start_time; | |
51 | int cpu; | |
52 | cpu = part_stat_lock(); | |
53 | part_stat_add(cpu, &mdev->vdisk->part0, ticks[rw], duration); | |
54 | part_round_stats(cpu, &mdev->vdisk->part0); | |
753c8913 | 55 | part_dec_in_flight(&mdev->vdisk->part0, rw); |
b411b363 | 56 | part_stat_unlock(); |
b411b363 PR |
57 | } |
58 | ||
59 | static void _req_is_done(struct drbd_conf *mdev, struct drbd_request *req, const int rw) | |
60 | { | |
61 | const unsigned long s = req->rq_state; | |
288f422e PR |
62 | |
63 | /* remove it from the transfer log. | |
64 | * well, only if it had been there in the first | |
65 | * place... if it had not (local only or conflicting | |
66 | * and never sent), it should still be "empty" as | |
67 | * initialized in drbd_req_new(), so we can list_del() it | |
68 | * here unconditionally */ | |
69 | list_del(&req->tl_requests); | |
70 | ||
b411b363 PR |
71 | /* if it was a write, we may have to set the corresponding |
72 | * bit(s) out-of-sync first. If it had a local part, we need to | |
73 | * release the reference to the activity log. */ | |
74 | if (rw == WRITE) { | |
b411b363 PR |
75 | /* Set out-of-sync unless both OK flags are set |
76 | * (local only or remote failed). | |
77 | * Other places where we set out-of-sync: | |
78 | * READ with local io-error */ | |
79 | if (!(s & RQ_NET_OK) || !(s & RQ_LOCAL_OK)) | |
ace652ac | 80 | drbd_set_out_of_sync(mdev, req->i.sector, req->i.size); |
b411b363 PR |
81 | |
82 | if ((s & RQ_NET_OK) && (s & RQ_LOCAL_OK) && (s & RQ_NET_SIS)) | |
ace652ac | 83 | drbd_set_in_sync(mdev, req->i.sector, req->i.size); |
b411b363 PR |
84 | |
85 | /* one might be tempted to move the drbd_al_complete_io | |
86 | * to the local io completion callback drbd_endio_pri. | |
87 | * but, if this was a mirror write, we may only | |
88 | * drbd_al_complete_io after this is RQ_NET_DONE, | |
89 | * otherwise the extent could be dropped from the al | |
90 | * before it has actually been written on the peer. | |
91 | * if we crash before our peer knows about the request, | |
92 | * but after the extent has been dropped from the al, | |
93 | * we would forget to resync the corresponding extent. | |
94 | */ | |
95 | if (s & RQ_LOCAL_MASK) { | |
96 | if (get_ldev_if_state(mdev, D_FAILED)) { | |
0778286a | 97 | if (s & RQ_IN_ACT_LOG) |
ace652ac | 98 | drbd_al_complete_io(mdev, req->i.sector); |
b411b363 PR |
99 | put_ldev(mdev); |
100 | } else if (__ratelimit(&drbd_ratelimit_state)) { | |
101 | dev_warn(DEV, "Should have called drbd_al_complete_io(, %llu), " | |
102 | "but my Disk seems to have failed :(\n", | |
ace652ac | 103 | (unsigned long long) req->i.sector); |
b411b363 PR |
104 | } |
105 | } | |
106 | } | |
107 | ||
32fa7e91 | 108 | drbd_req_free(req); |
b411b363 PR |
109 | } |
110 | ||
111 | static void queue_barrier(struct drbd_conf *mdev) | |
112 | { | |
113 | struct drbd_tl_epoch *b; | |
114 | ||
115 | /* We are within the req_lock. Once we queued the barrier for sending, | |
116 | * we set the CREATE_BARRIER bit. It is cleared as soon as a new | |
117 | * barrier/epoch object is added. This is the only place this bit is | |
118 | * set. It indicates that the barrier for this epoch is already queued, | |
119 | * and no new epoch has been created yet. */ | |
120 | if (test_bit(CREATE_BARRIER, &mdev->flags)) | |
121 | return; | |
122 | ||
123 | b = mdev->newest_tle; | |
124 | b->w.cb = w_send_barrier; | |
125 | /* inc_ap_pending done here, so we won't | |
126 | * get imbalanced on connection loss. | |
127 | * dec_ap_pending will be done in got_BarrierAck | |
128 | * or (on connection loss) in tl_clear. */ | |
129 | inc_ap_pending(mdev); | |
130 | drbd_queue_work(&mdev->data.work, &b->w); | |
131 | set_bit(CREATE_BARRIER, &mdev->flags); | |
132 | } | |
133 | ||
134 | static void _about_to_complete_local_write(struct drbd_conf *mdev, | |
135 | struct drbd_request *req) | |
136 | { | |
137 | const unsigned long s = req->rq_state; | |
b411b363 | 138 | |
8a3c1044 LE |
139 | /* Before we can signal completion to the upper layers, |
140 | * we may need to close the current epoch. | |
141 | * We can skip this, if this request has not even been sent, because we | |
142 | * did not have a fully established connection yet/anymore, during | |
143 | * bitmap exchange, or while we are C_AHEAD due to congestion policy. | |
144 | */ | |
145 | if (mdev->state.conn >= C_CONNECTED && | |
146 | (s & RQ_NET_SENT) != 0 && | |
b411b363 PR |
147 | req->epoch == mdev->newest_tle->br_number) |
148 | queue_barrier(mdev); | |
149 | ||
150 | /* we need to do the conflict detection stuff, | |
bb3bfe96 AG |
151 | * if the epoch_entries tree is non-empty and |
152 | * this request has completed on the network */ | |
153 | if ((s & RQ_NET_DONE) && !RB_EMPTY_ROOT(&mdev->epoch_entries)) { | |
ace652ac AG |
154 | const sector_t sector = req->i.sector; |
155 | const int size = req->i.size; | |
de696716 | 156 | struct drbd_interval *i; |
b411b363 PR |
157 | |
158 | /* ASSERT: | |
159 | * there must be no conflicting requests, since | |
160 | * they must have been failed on the spot */ | |
de696716 AG |
161 | |
162 | i = drbd_find_overlap(&mdev->write_requests, sector, size); | |
163 | if (i) { | |
164 | struct drbd_request *req2 = | |
165 | container_of(i, struct drbd_request, i); | |
166 | ||
167 | dev_alert(DEV, "LOGIC BUG: completed: %p %llus +%u; " | |
168 | "other: %p %llus +%u\n", | |
169 | req, (unsigned long long)sector, size, | |
170 | i, (unsigned long long)req2->i.sector, req2->i.size); | |
b411b363 PR |
171 | } |
172 | ||
173 | /* maybe "wake" those conflicting epoch entries | |
174 | * that wait for this request to finish. | |
175 | * | |
176 | * currently, there can be only _one_ such ee | |
177 | * (well, or some more, which would be pending | |
178 | * P_DISCARD_ACK not yet sent by the asender...), | |
179 | * since we block the receiver thread upon the | |
180 | * first conflict detection, which will wait on | |
181 | * misc_wait. maybe we want to assert that? | |
182 | * | |
183 | * anyways, if we found one, | |
184 | * we just have to do a wake_up. */ | |
8b946255 AG |
185 | i = drbd_find_overlap(&mdev->epoch_entries, sector, size); |
186 | if (i) | |
187 | wake_up(&mdev->misc_wait); | |
b411b363 | 188 | } |
b411b363 PR |
189 | } |
190 | ||
191 | void complete_master_bio(struct drbd_conf *mdev, | |
192 | struct bio_and_error *m) | |
193 | { | |
b411b363 PR |
194 | bio_endio(m->bio, m->error); |
195 | dec_ap_bio(mdev); | |
196 | } | |
197 | ||
198 | /* Helper for __req_mod(). | |
199 | * Set m->bio to the master bio, if it is fit to be completed, | |
200 | * or leave it alone (it is initialized to NULL in __req_mod), | |
201 | * if it has already been completed, or cannot be completed yet. | |
202 | * If m->bio is set, the error status to be returned is placed in m->error. | |
203 | */ | |
204 | void _req_may_be_done(struct drbd_request *req, struct bio_and_error *m) | |
205 | { | |
206 | const unsigned long s = req->rq_state; | |
207 | struct drbd_conf *mdev = req->mdev; | |
208 | /* only WRITES may end up here without a master bio (on barrier ack) */ | |
209 | int rw = req->master_bio ? bio_data_dir(req->master_bio) : WRITE; | |
210 | ||
b411b363 PR |
211 | /* we must not complete the master bio, while it is |
212 | * still being processed by _drbd_send_zc_bio (drbd_send_dblock) | |
213 | * not yet acknowledged by the peer | |
214 | * not yet completed by the local io subsystem | |
215 | * these flags may get cleared in any order by | |
216 | * the worker, | |
217 | * the receiver, | |
218 | * the bio_endio completion callbacks. | |
219 | */ | |
220 | if (s & RQ_NET_QUEUED) | |
221 | return; | |
222 | if (s & RQ_NET_PENDING) | |
223 | return; | |
224 | if (s & RQ_LOCAL_PENDING) | |
225 | return; | |
226 | ||
227 | if (req->master_bio) { | |
228 | /* this is data_received (remote read) | |
229 | * or protocol C P_WRITE_ACK | |
230 | * or protocol B P_RECV_ACK | |
231 | * or protocol A "handed_over_to_network" (SendAck) | |
232 | * or canceled or failed, | |
233 | * or killed from the transfer log due to connection loss. | |
234 | */ | |
235 | ||
236 | /* | |
237 | * figure out whether to report success or failure. | |
238 | * | |
239 | * report success when at least one of the operations succeeded. | |
240 | * or, to put the other way, | |
241 | * only report failure, when both operations failed. | |
242 | * | |
243 | * what to do about the failures is handled elsewhere. | |
244 | * what we need to do here is just: complete the master_bio. | |
245 | * | |
246 | * local completion error, if any, has been stored as ERR_PTR | |
247 | * in private_bio within drbd_endio_pri. | |
248 | */ | |
249 | int ok = (s & RQ_LOCAL_OK) || (s & RQ_NET_OK); | |
250 | int error = PTR_ERR(req->private_bio); | |
251 | ||
252 | /* remove the request from the conflict detection | |
253 | * respective block_id verification hash */ | |
dac1389c AG |
254 | if (!drbd_interval_empty(&req->i)) { |
255 | struct rb_root *root; | |
256 | ||
dac1389c AG |
257 | if (rw == WRITE) |
258 | root = &mdev->write_requests; | |
259 | else | |
260 | root = &mdev->read_requests; | |
261 | drbd_remove_interval(root, &req->i); | |
de696716 | 262 | } else |
8825f7c3 | 263 | D_ASSERT((s & (RQ_NET_MASK & ~RQ_NET_DONE)) == 0); |
b411b363 PR |
264 | |
265 | /* for writes we need to do some extra housekeeping */ | |
266 | if (rw == WRITE) | |
267 | _about_to_complete_local_write(mdev, req); | |
268 | ||
269 | /* Update disk stats */ | |
270 | _drbd_end_io_acct(mdev, req); | |
271 | ||
272 | m->error = ok ? 0 : (error ?: -EIO); | |
273 | m->bio = req->master_bio; | |
274 | req->master_bio = NULL; | |
275 | } | |
276 | ||
277 | if ((s & RQ_NET_MASK) == 0 || (s & RQ_NET_DONE)) { | |
278 | /* this is disconnected (local only) operation, | |
279 | * or protocol C P_WRITE_ACK, | |
280 | * or protocol A or B P_BARRIER_ACK, | |
281 | * or killed from the transfer log due to connection loss. */ | |
282 | _req_is_done(mdev, req, rw); | |
283 | } | |
284 | /* else: network part and not DONE yet. that is | |
285 | * protocol A or B, barrier ack still pending... */ | |
286 | } | |
287 | ||
cfa03415 PR |
288 | static void _req_may_be_done_not_susp(struct drbd_request *req, struct bio_and_error *m) |
289 | { | |
290 | struct drbd_conf *mdev = req->mdev; | |
291 | ||
fb22c402 | 292 | if (!is_susp(mdev->state)) |
cfa03415 PR |
293 | _req_may_be_done(req, m); |
294 | } | |
295 | ||
b411b363 PR |
296 | /* |
297 | * checks whether there was an overlapping request | |
298 | * or ee already registered. | |
299 | * | |
300 | * if so, return 1, in which case this request is completed on the spot, | |
301 | * without ever being submitted or send. | |
302 | * | |
303 | * return 0 if it is ok to submit this request. | |
304 | * | |
305 | * NOTE: | |
306 | * paranoia: assume something above us is broken, and issues different write | |
307 | * requests for the same block simultaneously... | |
308 | * | |
309 | * To ensure these won't be reordered differently on both nodes, resulting in | |
310 | * diverging data sets, we discard the later one(s). Not that this is supposed | |
311 | * to happen, but this is the rationale why we also have to check for | |
312 | * conflicting requests with local origin, and why we have to do so regardless | |
313 | * of whether we allowed multiple primaries. | |
314 | * | |
bb3bfe96 | 315 | * In case we only have one primary, the epoch_entries tree is empty. |
b411b363 PR |
316 | */ |
317 | static int _req_conflicts(struct drbd_request *req) | |
318 | { | |
319 | struct drbd_conf *mdev = req->mdev; | |
ace652ac AG |
320 | const sector_t sector = req->i.sector; |
321 | const int size = req->i.size; | |
de696716 | 322 | struct drbd_interval *i; |
b411b363 | 323 | |
dac1389c | 324 | D_ASSERT(drbd_interval_empty(&req->i)); |
b411b363 PR |
325 | |
326 | if (!get_net_conf(mdev)) | |
327 | return 0; | |
328 | ||
de696716 AG |
329 | i = drbd_find_overlap(&mdev->write_requests, sector, size); |
330 | if (i) { | |
331 | struct drbd_request *req2 = | |
332 | container_of(i, struct drbd_request, i); | |
333 | ||
334 | dev_alert(DEV, "%s[%u] Concurrent local write detected! " | |
335 | "[DISCARD L] new: %llus +%u; " | |
336 | "pending: %llus +%u\n", | |
337 | current->comm, current->pid, | |
338 | (unsigned long long)sector, size, | |
339 | (unsigned long long)req2->i.sector, req2->i.size); | |
340 | goto out_conflict; | |
b411b363 PR |
341 | } |
342 | ||
bb3bfe96 AG |
343 | if (!RB_EMPTY_ROOT(&mdev->epoch_entries)) { |
344 | /* check for overlapping requests with remote origin */ | |
8b946255 AG |
345 | i = drbd_find_overlap(&mdev->epoch_entries, sector, size); |
346 | if (i) { | |
347 | struct drbd_epoch_entry *e = | |
348 | container_of(i, struct drbd_epoch_entry, i); | |
349 | ||
350 | dev_alert(DEV, "%s[%u] Concurrent remote write detected!" | |
351 | " [DISCARD L] new: %llus +%u; " | |
352 | "pending: %llus +%u\n", | |
353 | current->comm, current->pid, | |
354 | (unsigned long long)sector, size, | |
355 | (unsigned long long)e->i.sector, e->i.size); | |
356 | goto out_conflict; | |
b411b363 PR |
357 | } |
358 | } | |
b411b363 | 359 | |
b411b363 PR |
360 | /* this is like it should be, and what we expected. |
361 | * our users do behave after all... */ | |
362 | put_net_conf(mdev); | |
363 | return 0; | |
364 | ||
365 | out_conflict: | |
366 | put_net_conf(mdev); | |
367 | return 1; | |
368 | } | |
369 | ||
370 | /* obviously this could be coded as many single functions | |
371 | * instead of one huge switch, | |
372 | * or by putting the code directly in the respective locations | |
373 | * (as it has been before). | |
374 | * | |
375 | * but having it this way | |
376 | * enforces that it is all in this one place, where it is easier to audit, | |
377 | * it makes it obvious that whatever "event" "happens" to a request should | |
378 | * happen "atomically" within the req_lock, | |
379 | * and it enforces that we have to think in a very structured manner | |
380 | * about the "events" that may happen to a request during its life time ... | |
381 | */ | |
2a80699f | 382 | int __req_mod(struct drbd_request *req, enum drbd_req_event what, |
b411b363 PR |
383 | struct bio_and_error *m) |
384 | { | |
385 | struct drbd_conf *mdev = req->mdev; | |
2a80699f | 386 | int rv = 0; |
b411b363 PR |
387 | m->bio = NULL; |
388 | ||
b411b363 PR |
389 | switch (what) { |
390 | default: | |
391 | dev_err(DEV, "LOGIC BUG in %s:%u\n", __FILE__ , __LINE__); | |
392 | break; | |
393 | ||
394 | /* does not happen... | |
395 | * initialization done in drbd_req_new | |
396 | case created: | |
397 | break; | |
398 | */ | |
399 | ||
400 | case to_be_send: /* via network */ | |
401 | /* reached via drbd_make_request_common | |
402 | * and from w_read_retry_remote */ | |
403 | D_ASSERT(!(req->rq_state & RQ_NET_MASK)); | |
404 | req->rq_state |= RQ_NET_PENDING; | |
405 | inc_ap_pending(mdev); | |
406 | break; | |
407 | ||
408 | case to_be_submitted: /* locally */ | |
409 | /* reached via drbd_make_request_common */ | |
410 | D_ASSERT(!(req->rq_state & RQ_LOCAL_MASK)); | |
411 | req->rq_state |= RQ_LOCAL_PENDING; | |
412 | break; | |
413 | ||
414 | case completed_ok: | |
415 | if (bio_data_dir(req->master_bio) == WRITE) | |
ace652ac | 416 | mdev->writ_cnt += req->i.size >> 9; |
b411b363 | 417 | else |
ace652ac | 418 | mdev->read_cnt += req->i.size >> 9; |
b411b363 PR |
419 | |
420 | req->rq_state |= (RQ_LOCAL_COMPLETED|RQ_LOCAL_OK); | |
421 | req->rq_state &= ~RQ_LOCAL_PENDING; | |
422 | ||
cfa03415 | 423 | _req_may_be_done_not_susp(req, m); |
b411b363 PR |
424 | put_ldev(mdev); |
425 | break; | |
426 | ||
427 | case write_completed_with_error: | |
428 | req->rq_state |= RQ_LOCAL_COMPLETED; | |
429 | req->rq_state &= ~RQ_LOCAL_PENDING; | |
430 | ||
81e84650 | 431 | __drbd_chk_io_error(mdev, false); |
cfa03415 | 432 | _req_may_be_done_not_susp(req, m); |
b411b363 PR |
433 | put_ldev(mdev); |
434 | break; | |
435 | ||
436 | case read_ahead_completed_with_error: | |
437 | /* it is legal to fail READA */ | |
438 | req->rq_state |= RQ_LOCAL_COMPLETED; | |
439 | req->rq_state &= ~RQ_LOCAL_PENDING; | |
cfa03415 | 440 | _req_may_be_done_not_susp(req, m); |
b411b363 PR |
441 | put_ldev(mdev); |
442 | break; | |
443 | ||
444 | case read_completed_with_error: | |
ace652ac | 445 | drbd_set_out_of_sync(mdev, req->i.sector, req->i.size); |
b411b363 PR |
446 | |
447 | req->rq_state |= RQ_LOCAL_COMPLETED; | |
448 | req->rq_state &= ~RQ_LOCAL_PENDING; | |
449 | ||
b411b363 | 450 | D_ASSERT(!(req->rq_state & RQ_NET_MASK)); |
b411b363 | 451 | |
81e84650 | 452 | __drbd_chk_io_error(mdev, false); |
b411b363 | 453 | put_ldev(mdev); |
b411b363 | 454 | |
d255e5ff LE |
455 | /* no point in retrying if there is no good remote data, |
456 | * or we have no connection. */ | |
457 | if (mdev->state.pdsk != D_UP_TO_DATE) { | |
cfa03415 | 458 | _req_may_be_done_not_susp(req, m); |
d255e5ff LE |
459 | break; |
460 | } | |
461 | ||
462 | /* _req_mod(req,to_be_send); oops, recursion... */ | |
463 | req->rq_state |= RQ_NET_PENDING; | |
464 | inc_ap_pending(mdev); | |
b411b363 PR |
465 | /* fall through: _req_mod(req,queue_for_net_read); */ |
466 | ||
467 | case queue_for_net_read: | |
468 | /* READ or READA, and | |
469 | * no local disk, | |
470 | * or target area marked as invalid, | |
471 | * or just got an io-error. */ | |
472 | /* from drbd_make_request_common | |
473 | * or from bio_endio during read io-error recovery */ | |
474 | ||
475 | /* so we can verify the handle in the answer packet | |
476 | * corresponding hlist_del is in _req_may_be_done() */ | |
dac1389c | 477 | drbd_insert_interval(&mdev->read_requests, &req->i); |
b411b363 | 478 | |
83c38830 | 479 | set_bit(UNPLUG_REMOTE, &mdev->flags); |
b411b363 PR |
480 | |
481 | D_ASSERT(req->rq_state & RQ_NET_PENDING); | |
482 | req->rq_state |= RQ_NET_QUEUED; | |
483 | req->w.cb = (req->rq_state & RQ_LOCAL_MASK) | |
484 | ? w_read_retry_remote | |
485 | : w_send_read_req; | |
486 | drbd_queue_work(&mdev->data.work, &req->w); | |
487 | break; | |
488 | ||
489 | case queue_for_net_write: | |
490 | /* assert something? */ | |
491 | /* from drbd_make_request_common only */ | |
492 | ||
b411b363 | 493 | /* corresponding hlist_del is in _req_may_be_done() */ |
de696716 | 494 | drbd_insert_interval(&mdev->write_requests, &req->i); |
b411b363 PR |
495 | |
496 | /* NOTE | |
497 | * In case the req ended up on the transfer log before being | |
498 | * queued on the worker, it could lead to this request being | |
499 | * missed during cleanup after connection loss. | |
500 | * So we have to do both operations here, | |
501 | * within the same lock that protects the transfer log. | |
502 | * | |
503 | * _req_add_to_epoch(req); this has to be after the | |
504 | * _maybe_start_new_epoch(req); which happened in | |
505 | * drbd_make_request_common, because we now may set the bit | |
506 | * again ourselves to close the current epoch. | |
507 | * | |
508 | * Add req to the (now) current epoch (barrier). */ | |
509 | ||
83c38830 LE |
510 | /* otherwise we may lose an unplug, which may cause some remote |
511 | * io-scheduler timeout to expire, increasing maximum latency, | |
512 | * hurting performance. */ | |
513 | set_bit(UNPLUG_REMOTE, &mdev->flags); | |
514 | ||
b411b363 PR |
515 | /* see drbd_make_request_common, |
516 | * just after it grabs the req_lock */ | |
517 | D_ASSERT(test_bit(CREATE_BARRIER, &mdev->flags) == 0); | |
518 | ||
519 | req->epoch = mdev->newest_tle->br_number; | |
b411b363 PR |
520 | |
521 | /* increment size of current epoch */ | |
7e602c0a | 522 | mdev->newest_tle->n_writes++; |
b411b363 PR |
523 | |
524 | /* queue work item to send data */ | |
525 | D_ASSERT(req->rq_state & RQ_NET_PENDING); | |
526 | req->rq_state |= RQ_NET_QUEUED; | |
527 | req->w.cb = w_send_dblock; | |
528 | drbd_queue_work(&mdev->data.work, &req->w); | |
529 | ||
530 | /* close the epoch, in case it outgrew the limit */ | |
7e602c0a | 531 | if (mdev->newest_tle->n_writes >= mdev->net_conf->max_epoch_size) |
b411b363 PR |
532 | queue_barrier(mdev); |
533 | ||
534 | break; | |
535 | ||
73a01a18 PR |
536 | case queue_for_send_oos: |
537 | req->rq_state |= RQ_NET_QUEUED; | |
538 | req->w.cb = w_send_oos; | |
539 | drbd_queue_work(&mdev->data.work, &req->w); | |
540 | break; | |
541 | ||
542 | case oos_handed_to_network: | |
543 | /* actually the same */ | |
b411b363 PR |
544 | case send_canceled: |
545 | /* treat it the same */ | |
546 | case send_failed: | |
547 | /* real cleanup will be done from tl_clear. just update flags | |
548 | * so it is no longer marked as on the worker queue */ | |
549 | req->rq_state &= ~RQ_NET_QUEUED; | |
550 | /* if we did it right, tl_clear should be scheduled only after | |
551 | * this, so this should not be necessary! */ | |
cfa03415 | 552 | _req_may_be_done_not_susp(req, m); |
b411b363 PR |
553 | break; |
554 | ||
555 | case handed_over_to_network: | |
556 | /* assert something? */ | |
759fbdfb | 557 | if (bio_data_dir(req->master_bio) == WRITE) |
ace652ac | 558 | atomic_add(req->i.size >> 9, &mdev->ap_in_flight); |
759fbdfb | 559 | |
b411b363 PR |
560 | if (bio_data_dir(req->master_bio) == WRITE && |
561 | mdev->net_conf->wire_protocol == DRBD_PROT_A) { | |
562 | /* this is what is dangerous about protocol A: | |
563 | * pretend it was successfully written on the peer. */ | |
564 | if (req->rq_state & RQ_NET_PENDING) { | |
565 | dec_ap_pending(mdev); | |
566 | req->rq_state &= ~RQ_NET_PENDING; | |
567 | req->rq_state |= RQ_NET_OK; | |
568 | } /* else: neg-ack was faster... */ | |
569 | /* it is still not yet RQ_NET_DONE until the | |
570 | * corresponding epoch barrier got acked as well, | |
571 | * so we know what to dirty on connection loss */ | |
572 | } | |
573 | req->rq_state &= ~RQ_NET_QUEUED; | |
574 | req->rq_state |= RQ_NET_SENT; | |
575 | /* because _drbd_send_zc_bio could sleep, and may want to | |
576 | * dereference the bio even after the "write_acked_by_peer" and | |
577 | * "completed_ok" events came in, once we return from | |
578 | * _drbd_send_zc_bio (drbd_send_dblock), we have to check | |
579 | * whether it is done already, and end it. */ | |
cfa03415 | 580 | _req_may_be_done_not_susp(req, m); |
b411b363 PR |
581 | break; |
582 | ||
d255e5ff LE |
583 | case read_retry_remote_canceled: |
584 | req->rq_state &= ~RQ_NET_QUEUED; | |
585 | /* fall through, in case we raced with drbd_disconnect */ | |
b411b363 PR |
586 | case connection_lost_while_pending: |
587 | /* transfer log cleanup after connection loss */ | |
588 | /* assert something? */ | |
589 | if (req->rq_state & RQ_NET_PENDING) | |
590 | dec_ap_pending(mdev); | |
591 | req->rq_state &= ~(RQ_NET_OK|RQ_NET_PENDING); | |
592 | req->rq_state |= RQ_NET_DONE; | |
759fbdfb | 593 | if (req->rq_state & RQ_NET_SENT && req->rq_state & RQ_WRITE) |
ace652ac | 594 | atomic_sub(req->i.size >> 9, &mdev->ap_in_flight); |
759fbdfb | 595 | |
b411b363 PR |
596 | /* if it is still queued, we may not complete it here. |
597 | * it will be canceled soon. */ | |
598 | if (!(req->rq_state & RQ_NET_QUEUED)) | |
cfa03415 | 599 | _req_may_be_done(req, m); /* Allowed while state.susp */ |
b411b363 PR |
600 | break; |
601 | ||
602 | case write_acked_by_peer_and_sis: | |
603 | req->rq_state |= RQ_NET_SIS; | |
604 | case conflict_discarded_by_peer: | |
605 | /* for discarded conflicting writes of multiple primaries, | |
606 | * there is no need to keep anything in the tl, potential | |
607 | * node crashes are covered by the activity log. */ | |
608 | if (what == conflict_discarded_by_peer) | |
609 | dev_alert(DEV, "Got DiscardAck packet %llus +%u!" | |
610 | " DRBD is not a random data generator!\n", | |
ace652ac | 611 | (unsigned long long)req->i.sector, req->i.size); |
b411b363 PR |
612 | req->rq_state |= RQ_NET_DONE; |
613 | /* fall through */ | |
614 | case write_acked_by_peer: | |
615 | /* protocol C; successfully written on peer. | |
616 | * Nothing to do here. | |
617 | * We want to keep the tl in place for all protocols, to cater | |
618 | * for volatile write-back caches on lower level devices. | |
619 | * | |
620 | * A barrier request is expected to have forced all prior | |
621 | * requests onto stable storage, so completion of a barrier | |
622 | * request could set NET_DONE right here, and not wait for the | |
623 | * P_BARRIER_ACK, but that is an unnecessary optimization. */ | |
624 | ||
625 | /* this makes it effectively the same as for: */ | |
626 | case recv_acked_by_peer: | |
627 | /* protocol B; pretends to be successfully written on peer. | |
628 | * see also notes above in handed_over_to_network about | |
629 | * protocol != C */ | |
630 | req->rq_state |= RQ_NET_OK; | |
631 | D_ASSERT(req->rq_state & RQ_NET_PENDING); | |
632 | dec_ap_pending(mdev); | |
ace652ac | 633 | atomic_sub(req->i.size >> 9, &mdev->ap_in_flight); |
b411b363 | 634 | req->rq_state &= ~RQ_NET_PENDING; |
cfa03415 | 635 | _req_may_be_done_not_susp(req, m); |
b411b363 PR |
636 | break; |
637 | ||
638 | case neg_acked: | |
639 | /* assert something? */ | |
759fbdfb | 640 | if (req->rq_state & RQ_NET_PENDING) { |
b411b363 | 641 | dec_ap_pending(mdev); |
ace652ac | 642 | atomic_sub(req->i.size >> 9, &mdev->ap_in_flight); |
759fbdfb | 643 | } |
b411b363 PR |
644 | req->rq_state &= ~(RQ_NET_OK|RQ_NET_PENDING); |
645 | ||
646 | req->rq_state |= RQ_NET_DONE; | |
cfa03415 | 647 | _req_may_be_done_not_susp(req, m); |
b411b363 PR |
648 | /* else: done by handed_over_to_network */ |
649 | break; | |
650 | ||
265be2d0 PR |
651 | case fail_frozen_disk_io: |
652 | if (!(req->rq_state & RQ_LOCAL_COMPLETED)) | |
653 | break; | |
654 | ||
cfa03415 | 655 | _req_may_be_done(req, m); /* Allowed while state.susp */ |
265be2d0 PR |
656 | break; |
657 | ||
658 | case restart_frozen_disk_io: | |
659 | if (!(req->rq_state & RQ_LOCAL_COMPLETED)) | |
660 | break; | |
661 | ||
662 | req->rq_state &= ~RQ_LOCAL_COMPLETED; | |
663 | ||
664 | rv = MR_READ; | |
665 | if (bio_data_dir(req->master_bio) == WRITE) | |
666 | rv = MR_WRITE; | |
667 | ||
668 | get_ldev(mdev); | |
669 | req->w.cb = w_restart_disk_io; | |
670 | drbd_queue_work(&mdev->data.work, &req->w); | |
671 | break; | |
672 | ||
11b58e73 PR |
673 | case resend: |
674 | /* If RQ_NET_OK is already set, we got a P_WRITE_ACK or P_RECV_ACK | |
47ff2d0a | 675 | before the connection loss (B&C only); only P_BARRIER_ACK was missing. |
11b58e73 | 676 | Trowing them out of the TL here by pretending we got a BARRIER_ACK |
481c6f50 | 677 | We ensure that the peer was not rebooted */ |
11b58e73 PR |
678 | if (!(req->rq_state & RQ_NET_OK)) { |
679 | if (req->w.cb) { | |
680 | drbd_queue_work(&mdev->data.work, &req->w); | |
681 | rv = req->rq_state & RQ_WRITE ? MR_WRITE : MR_READ; | |
682 | } | |
683 | break; | |
684 | } | |
685 | /* else, fall through to barrier_acked */ | |
686 | ||
b411b363 | 687 | case barrier_acked: |
288f422e PR |
688 | if (!(req->rq_state & RQ_WRITE)) |
689 | break; | |
690 | ||
b411b363 PR |
691 | if (req->rq_state & RQ_NET_PENDING) { |
692 | /* barrier came in before all requests have been acked. | |
693 | * this is bad, because if the connection is lost now, | |
694 | * we won't be able to clean them up... */ | |
695 | dev_err(DEV, "FIXME (barrier_acked but pending)\n"); | |
b411b363 PR |
696 | list_move(&req->tl_requests, &mdev->out_of_sequence_requests); |
697 | } | |
e636db5b LE |
698 | if ((req->rq_state & RQ_NET_MASK) != 0) { |
699 | req->rq_state |= RQ_NET_DONE; | |
700 | if (mdev->net_conf->wire_protocol == DRBD_PROT_A) | |
ace652ac | 701 | atomic_sub(req->i.size >> 9, &mdev->ap_in_flight); |
e636db5b | 702 | } |
cfa03415 | 703 | _req_may_be_done(req, m); /* Allowed while state.susp */ |
b411b363 PR |
704 | break; |
705 | ||
706 | case data_received: | |
707 | D_ASSERT(req->rq_state & RQ_NET_PENDING); | |
708 | dec_ap_pending(mdev); | |
709 | req->rq_state &= ~RQ_NET_PENDING; | |
710 | req->rq_state |= (RQ_NET_OK|RQ_NET_DONE); | |
cfa03415 | 711 | _req_may_be_done_not_susp(req, m); |
b411b363 PR |
712 | break; |
713 | }; | |
2a80699f PR |
714 | |
715 | return rv; | |
b411b363 PR |
716 | } |
717 | ||
718 | /* we may do a local read if: | |
719 | * - we are consistent (of course), | |
720 | * - or we are generally inconsistent, | |
721 | * BUT we are still/already IN SYNC for this area. | |
722 | * since size may be bigger than BM_BLOCK_SIZE, | |
723 | * we may need to check several bits. | |
724 | */ | |
725 | static int drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int size) | |
726 | { | |
727 | unsigned long sbnr, ebnr; | |
728 | sector_t esector, nr_sectors; | |
729 | ||
730 | if (mdev->state.disk == D_UP_TO_DATE) | |
731 | return 1; | |
732 | if (mdev->state.disk >= D_OUTDATED) | |
733 | return 0; | |
734 | if (mdev->state.disk < D_INCONSISTENT) | |
735 | return 0; | |
736 | /* state.disk == D_INCONSISTENT We will have a look at the BitMap */ | |
737 | nr_sectors = drbd_get_capacity(mdev->this_bdev); | |
738 | esector = sector + (size >> 9) - 1; | |
739 | ||
740 | D_ASSERT(sector < nr_sectors); | |
741 | D_ASSERT(esector < nr_sectors); | |
742 | ||
743 | sbnr = BM_SECT_TO_BIT(sector); | |
744 | ebnr = BM_SECT_TO_BIT(esector); | |
745 | ||
746 | return 0 == drbd_bm_count_bits(mdev, sbnr, ebnr); | |
747 | } | |
748 | ||
aeda1cd6 | 749 | static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time) |
b411b363 PR |
750 | { |
751 | const int rw = bio_rw(bio); | |
752 | const int size = bio->bi_size; | |
753 | const sector_t sector = bio->bi_sector; | |
754 | struct drbd_tl_epoch *b = NULL; | |
755 | struct drbd_request *req; | |
73a01a18 | 756 | int local, remote, send_oos = 0; |
b411b363 | 757 | int err = -EIO; |
9a25a04c | 758 | int ret = 0; |
b411b363 PR |
759 | |
760 | /* allocate outside of all locks; */ | |
761 | req = drbd_req_new(mdev, bio); | |
762 | if (!req) { | |
763 | dec_ap_bio(mdev); | |
764 | /* only pass the error to the upper layers. | |
765 | * if user cannot handle io errors, that's not our business. */ | |
766 | dev_err(DEV, "could not kmalloc() req\n"); | |
767 | bio_endio(bio, -ENOMEM); | |
768 | return 0; | |
769 | } | |
aeda1cd6 | 770 | req->start_time = start_time; |
b411b363 | 771 | |
b411b363 PR |
772 | local = get_ldev(mdev); |
773 | if (!local) { | |
774 | bio_put(req->private_bio); /* or we get a bio leak */ | |
775 | req->private_bio = NULL; | |
776 | } | |
777 | if (rw == WRITE) { | |
778 | remote = 1; | |
779 | } else { | |
780 | /* READ || READA */ | |
781 | if (local) { | |
782 | if (!drbd_may_do_local_read(mdev, sector, size)) { | |
783 | /* we could kick the syncer to | |
784 | * sync this extent asap, wait for | |
785 | * it, then continue locally. | |
786 | * Or just issue the request remotely. | |
787 | */ | |
788 | local = 0; | |
789 | bio_put(req->private_bio); | |
790 | req->private_bio = NULL; | |
791 | put_ldev(mdev); | |
792 | } | |
793 | } | |
794 | remote = !local && mdev->state.pdsk >= D_UP_TO_DATE; | |
795 | } | |
796 | ||
797 | /* If we have a disk, but a READA request is mapped to remote, | |
798 | * we are R_PRIMARY, D_INCONSISTENT, SyncTarget. | |
799 | * Just fail that READA request right here. | |
800 | * | |
801 | * THINK: maybe fail all READA when not local? | |
802 | * or make this configurable... | |
803 | * if network is slow, READA won't do any good. | |
804 | */ | |
805 | if (rw == READA && mdev->state.disk >= D_INCONSISTENT && !local) { | |
806 | err = -EWOULDBLOCK; | |
807 | goto fail_and_free_req; | |
808 | } | |
809 | ||
810 | /* For WRITES going to the local disk, grab a reference on the target | |
811 | * extent. This waits for any resync activity in the corresponding | |
812 | * resync extent to finish, and, if necessary, pulls in the target | |
813 | * extent into the activity log, which involves further disk io because | |
814 | * of transactional on-disk meta data updates. */ | |
0778286a PR |
815 | if (rw == WRITE && local && !test_bit(AL_SUSPENDED, &mdev->flags)) { |
816 | req->rq_state |= RQ_IN_ACT_LOG; | |
b411b363 | 817 | drbd_al_begin_io(mdev, sector); |
0778286a | 818 | } |
b411b363 | 819 | |
6a35c45f PR |
820 | remote = remote && drbd_should_do_remote(mdev->state); |
821 | send_oos = rw == WRITE && drbd_should_send_oos(mdev->state); | |
3719094e | 822 | D_ASSERT(!(remote && send_oos)); |
b411b363 | 823 | |
fb22c402 | 824 | if (!(local || remote) && !is_susp(mdev->state)) { |
fb2c7a10 LE |
825 | if (__ratelimit(&drbd_ratelimit_state)) |
826 | dev_err(DEV, "IO ERROR: neither local nor remote disk\n"); | |
b411b363 PR |
827 | goto fail_free_complete; |
828 | } | |
829 | ||
830 | /* For WRITE request, we have to make sure that we have an | |
831 | * unused_spare_tle, in case we need to start a new epoch. | |
832 | * I try to be smart and avoid to pre-allocate always "just in case", | |
833 | * but there is a race between testing the bit and pointer outside the | |
834 | * spinlock, and grabbing the spinlock. | |
835 | * if we lost that race, we retry. */ | |
73a01a18 | 836 | if (rw == WRITE && (remote || send_oos) && |
b411b363 PR |
837 | mdev->unused_spare_tle == NULL && |
838 | test_bit(CREATE_BARRIER, &mdev->flags)) { | |
839 | allocate_barrier: | |
840 | b = kmalloc(sizeof(struct drbd_tl_epoch), GFP_NOIO); | |
841 | if (!b) { | |
842 | dev_err(DEV, "Failed to alloc barrier.\n"); | |
843 | err = -ENOMEM; | |
844 | goto fail_free_complete; | |
845 | } | |
846 | } | |
847 | ||
848 | /* GOOD, everything prepared, grab the spin_lock */ | |
849 | spin_lock_irq(&mdev->req_lock); | |
850 | ||
fb22c402 | 851 | if (is_susp(mdev->state)) { |
9a25a04c PR |
852 | /* If we got suspended, use the retry mechanism of |
853 | generic_make_request() to restart processing of this | |
2f58dcfc | 854 | bio. In the next call to drbd_make_request |
9a25a04c PR |
855 | we sleep in inc_ap_bio() */ |
856 | ret = 1; | |
857 | spin_unlock_irq(&mdev->req_lock); | |
858 | goto fail_free_complete; | |
859 | } | |
860 | ||
73a01a18 | 861 | if (remote || send_oos) { |
6a35c45f PR |
862 | remote = drbd_should_do_remote(mdev->state); |
863 | send_oos = rw == WRITE && drbd_should_send_oos(mdev->state); | |
3719094e | 864 | D_ASSERT(!(remote && send_oos)); |
73a01a18 PR |
865 | |
866 | if (!(remote || send_oos)) | |
b411b363 PR |
867 | dev_warn(DEV, "lost connection while grabbing the req_lock!\n"); |
868 | if (!(local || remote)) { | |
869 | dev_err(DEV, "IO ERROR: neither local nor remote disk\n"); | |
870 | spin_unlock_irq(&mdev->req_lock); | |
871 | goto fail_free_complete; | |
872 | } | |
873 | } | |
874 | ||
875 | if (b && mdev->unused_spare_tle == NULL) { | |
876 | mdev->unused_spare_tle = b; | |
877 | b = NULL; | |
878 | } | |
73a01a18 | 879 | if (rw == WRITE && (remote || send_oos) && |
b411b363 PR |
880 | mdev->unused_spare_tle == NULL && |
881 | test_bit(CREATE_BARRIER, &mdev->flags)) { | |
882 | /* someone closed the current epoch | |
883 | * while we were grabbing the spinlock */ | |
884 | spin_unlock_irq(&mdev->req_lock); | |
885 | goto allocate_barrier; | |
886 | } | |
887 | ||
888 | ||
889 | /* Update disk stats */ | |
890 | _drbd_start_io_acct(mdev, req, bio); | |
891 | ||
892 | /* _maybe_start_new_epoch(mdev); | |
893 | * If we need to generate a write barrier packet, we have to add the | |
894 | * new epoch (barrier) object, and queue the barrier packet for sending, | |
895 | * and queue the req's data after it _within the same lock_, otherwise | |
896 | * we have race conditions were the reorder domains could be mixed up. | |
897 | * | |
898 | * Even read requests may start a new epoch and queue the corresponding | |
899 | * barrier packet. To get the write ordering right, we only have to | |
900 | * make sure that, if this is a write request and it triggered a | |
901 | * barrier packet, this request is queued within the same spinlock. */ | |
73a01a18 | 902 | if ((remote || send_oos) && mdev->unused_spare_tle && |
b411b363 PR |
903 | test_and_clear_bit(CREATE_BARRIER, &mdev->flags)) { |
904 | _tl_add_barrier(mdev, mdev->unused_spare_tle); | |
905 | mdev->unused_spare_tle = NULL; | |
906 | } else { | |
907 | D_ASSERT(!(remote && rw == WRITE && | |
908 | test_bit(CREATE_BARRIER, &mdev->flags))); | |
909 | } | |
910 | ||
911 | /* NOTE | |
912 | * Actually, 'local' may be wrong here already, since we may have failed | |
913 | * to write to the meta data, and may become wrong anytime because of | |
914 | * local io-error for some other request, which would lead to us | |
915 | * "detaching" the local disk. | |
916 | * | |
917 | * 'remote' may become wrong any time because the network could fail. | |
918 | * | |
919 | * This is a harmless race condition, though, since it is handled | |
920 | * correctly at the appropriate places; so it just defers the failure | |
921 | * of the respective operation. | |
922 | */ | |
923 | ||
924 | /* mark them early for readability. | |
925 | * this just sets some state flags. */ | |
926 | if (remote) | |
927 | _req_mod(req, to_be_send); | |
928 | if (local) | |
929 | _req_mod(req, to_be_submitted); | |
930 | ||
931 | /* check this request on the collision detection hash tables. | |
932 | * if we have a conflict, just complete it here. | |
933 | * THINK do we want to check reads, too? (I don't think so...) */ | |
d28fd092 LE |
934 | if (rw == WRITE && _req_conflicts(req)) |
935 | goto fail_conflicting; | |
288f422e PR |
936 | |
937 | list_add_tail(&req->tl_requests, &mdev->newest_tle->requests); | |
938 | ||
b411b363 PR |
939 | /* NOTE remote first: to get the concurrent write detection right, |
940 | * we must register the request before start of local IO. */ | |
941 | if (remote) { | |
942 | /* either WRITE and C_CONNECTED, | |
943 | * or READ, and no local disk, | |
944 | * or READ, but not in sync. | |
945 | */ | |
946 | _req_mod(req, (rw == WRITE) | |
947 | ? queue_for_net_write | |
948 | : queue_for_net_read); | |
949 | } | |
73a01a18 PR |
950 | if (send_oos && drbd_set_out_of_sync(mdev, sector, size)) |
951 | _req_mod(req, queue_for_send_oos); | |
67531718 | 952 | |
73a01a18 PR |
953 | if (remote && |
954 | mdev->net_conf->on_congestion != OC_BLOCK && mdev->agreed_pro_version >= 96) { | |
67531718 PR |
955 | int congested = 0; |
956 | ||
957 | if (mdev->net_conf->cong_fill && | |
958 | atomic_read(&mdev->ap_in_flight) >= mdev->net_conf->cong_fill) { | |
959 | dev_info(DEV, "Congestion-fill threshold reached\n"); | |
960 | congested = 1; | |
961 | } | |
962 | ||
963 | if (mdev->act_log->used >= mdev->net_conf->cong_extents) { | |
964 | dev_info(DEV, "Congestion-extents threshold reached\n"); | |
965 | congested = 1; | |
966 | } | |
967 | ||
71c78cfb | 968 | if (congested) { |
039312b6 | 969 | queue_barrier(mdev); /* last barrier, after mirrored writes */ |
73a01a18 | 970 | |
67531718 PR |
971 | if (mdev->net_conf->on_congestion == OC_PULL_AHEAD) |
972 | _drbd_set_state(_NS(mdev, conn, C_AHEAD), 0, NULL); | |
973 | else /*mdev->net_conf->on_congestion == OC_DISCONNECT */ | |
974 | _drbd_set_state(_NS(mdev, conn, C_DISCONNECTING), 0, NULL); | |
975 | } | |
976 | } | |
977 | ||
b411b363 PR |
978 | spin_unlock_irq(&mdev->req_lock); |
979 | kfree(b); /* if someone else has beaten us to it... */ | |
980 | ||
981 | if (local) { | |
982 | req->private_bio->bi_bdev = mdev->ldev->backing_bdev; | |
983 | ||
6719fb03 LE |
984 | /* State may have changed since we grabbed our reference on the |
985 | * mdev->ldev member. Double check, and short-circuit to endio. | |
986 | * In case the last activity log transaction failed to get on | |
987 | * stable storage, and this is a WRITE, we may not even submit | |
988 | * this bio. */ | |
989 | if (get_ldev(mdev)) { | |
0cf9d27e AG |
990 | if (drbd_insert_fault(mdev, rw == WRITE ? DRBD_FAULT_DT_WR |
991 | : rw == READ ? DRBD_FAULT_DT_RD | |
992 | : DRBD_FAULT_DT_RA)) | |
6719fb03 LE |
993 | bio_endio(req->private_bio, -EIO); |
994 | else | |
995 | generic_make_request(req->private_bio); | |
996 | put_ldev(mdev); | |
997 | } else | |
b411b363 | 998 | bio_endio(req->private_bio, -EIO); |
b411b363 PR |
999 | } |
1000 | ||
b411b363 PR |
1001 | return 0; |
1002 | ||
d28fd092 LE |
1003 | fail_conflicting: |
1004 | /* this is a conflicting request. | |
1005 | * even though it may have been only _partially_ | |
1006 | * overlapping with one of the currently pending requests, | |
1007 | * without even submitting or sending it, we will | |
1008 | * pretend that it was successfully served right now. | |
1009 | */ | |
1010 | _drbd_end_io_acct(mdev, req); | |
1011 | spin_unlock_irq(&mdev->req_lock); | |
1012 | if (remote) | |
1013 | dec_ap_pending(mdev); | |
1014 | /* THINK: do we want to fail it (-EIO), or pretend success? | |
1015 | * this pretends success. */ | |
1016 | err = 0; | |
1017 | ||
b411b363 | 1018 | fail_free_complete: |
76727f68 | 1019 | if (req->rq_state & RQ_IN_ACT_LOG) |
b411b363 PR |
1020 | drbd_al_complete_io(mdev, sector); |
1021 | fail_and_free_req: | |
1022 | if (local) { | |
1023 | bio_put(req->private_bio); | |
1024 | req->private_bio = NULL; | |
1025 | put_ldev(mdev); | |
1026 | } | |
9a25a04c PR |
1027 | if (!ret) |
1028 | bio_endio(bio, err); | |
1029 | ||
b411b363 PR |
1030 | drbd_req_free(req); |
1031 | dec_ap_bio(mdev); | |
1032 | kfree(b); | |
1033 | ||
9a25a04c | 1034 | return ret; |
b411b363 PR |
1035 | } |
1036 | ||
1037 | /* helper function for drbd_make_request | |
1038 | * if we can determine just by the mdev (state) that this request will fail, | |
1039 | * return 1 | |
1040 | * otherwise return 0 | |
1041 | */ | |
1042 | static int drbd_fail_request_early(struct drbd_conf *mdev, int is_write) | |
1043 | { | |
b411b363 PR |
1044 | if (mdev->state.role != R_PRIMARY && |
1045 | (!allow_oos || is_write)) { | |
1046 | if (__ratelimit(&drbd_ratelimit_state)) { | |
1047 | dev_err(DEV, "Process %s[%u] tried to %s; " | |
1048 | "since we are not in Primary state, " | |
1049 | "we cannot allow this\n", | |
1050 | current->comm, current->pid, | |
1051 | is_write ? "WRITE" : "READ"); | |
1052 | } | |
1053 | return 1; | |
1054 | } | |
1055 | ||
b411b363 PR |
1056 | return 0; |
1057 | } | |
1058 | ||
2f58dcfc | 1059 | int drbd_make_request(struct request_queue *q, struct bio *bio) |
b411b363 PR |
1060 | { |
1061 | unsigned int s_enr, e_enr; | |
1062 | struct drbd_conf *mdev = (struct drbd_conf *) q->queuedata; | |
aeda1cd6 | 1063 | unsigned long start_time; |
b411b363 PR |
1064 | |
1065 | if (drbd_fail_request_early(mdev, bio_data_dir(bio) & WRITE)) { | |
1066 | bio_endio(bio, -EPERM); | |
1067 | return 0; | |
1068 | } | |
1069 | ||
aeda1cd6 PR |
1070 | start_time = jiffies; |
1071 | ||
b411b363 PR |
1072 | /* |
1073 | * what we "blindly" assume: | |
1074 | */ | |
1075 | D_ASSERT(bio->bi_size > 0); | |
1076 | D_ASSERT((bio->bi_size & 0x1ff) == 0); | |
1077 | D_ASSERT(bio->bi_idx == 0); | |
1078 | ||
1079 | /* to make some things easier, force alignment of requests within the | |
1080 | * granularity of our hash tables */ | |
1081 | s_enr = bio->bi_sector >> HT_SHIFT; | |
1082 | e_enr = (bio->bi_sector+(bio->bi_size>>9)-1) >> HT_SHIFT; | |
1083 | ||
1084 | if (likely(s_enr == e_enr)) { | |
1085 | inc_ap_bio(mdev, 1); | |
aeda1cd6 | 1086 | return drbd_make_request_common(mdev, bio, start_time); |
b411b363 PR |
1087 | } |
1088 | ||
1089 | /* can this bio be split generically? | |
1090 | * Maybe add our own split-arbitrary-bios function. */ | |
1816a2b4 | 1091 | if (bio->bi_vcnt != 1 || bio->bi_idx != 0 || bio->bi_size > DRBD_MAX_BIO_SIZE) { |
b411b363 PR |
1092 | /* rather error out here than BUG in bio_split */ |
1093 | dev_err(DEV, "bio would need to, but cannot, be split: " | |
1094 | "(vcnt=%u,idx=%u,size=%u,sector=%llu)\n", | |
1095 | bio->bi_vcnt, bio->bi_idx, bio->bi_size, | |
1096 | (unsigned long long)bio->bi_sector); | |
1097 | bio_endio(bio, -EINVAL); | |
1098 | } else { | |
1099 | /* This bio crosses some boundary, so we have to split it. */ | |
1100 | struct bio_pair *bp; | |
1101 | /* works for the "do not cross hash slot boundaries" case | |
1102 | * e.g. sector 262269, size 4096 | |
1103 | * s_enr = 262269 >> 6 = 4097 | |
1104 | * e_enr = (262269+8-1) >> 6 = 4098 | |
1105 | * HT_SHIFT = 6 | |
1106 | * sps = 64, mask = 63 | |
1107 | * first_sectors = 64 - (262269 & 63) = 3 | |
1108 | */ | |
1109 | const sector_t sect = bio->bi_sector; | |
1110 | const int sps = 1 << HT_SHIFT; /* sectors per slot */ | |
1111 | const int mask = sps - 1; | |
1112 | const sector_t first_sectors = sps - (sect & mask); | |
03567812 | 1113 | bp = bio_split(bio, first_sectors); |
b411b363 PR |
1114 | |
1115 | /* we need to get a "reference count" (ap_bio_cnt) | |
1116 | * to avoid races with the disconnect/reconnect/suspend code. | |
9a25a04c | 1117 | * In case we need to split the bio here, we need to get three references |
b411b363 PR |
1118 | * atomically, otherwise we might deadlock when trying to submit the |
1119 | * second one! */ | |
9a25a04c | 1120 | inc_ap_bio(mdev, 3); |
b411b363 PR |
1121 | |
1122 | D_ASSERT(e_enr == s_enr + 1); | |
1123 | ||
aeda1cd6 | 1124 | while (drbd_make_request_common(mdev, &bp->bio1, start_time)) |
9a25a04c PR |
1125 | inc_ap_bio(mdev, 1); |
1126 | ||
aeda1cd6 | 1127 | while (drbd_make_request_common(mdev, &bp->bio2, start_time)) |
9a25a04c PR |
1128 | inc_ap_bio(mdev, 1); |
1129 | ||
1130 | dec_ap_bio(mdev); | |
1131 | ||
b411b363 PR |
1132 | bio_pair_release(bp); |
1133 | } | |
1134 | return 0; | |
1135 | } | |
1136 | ||
1137 | /* This is called by bio_add_page(). With this function we reduce | |
1816a2b4 | 1138 | * the number of BIOs that span over multiple DRBD_MAX_BIO_SIZEs |
b411b363 PR |
1139 | * units (was AL_EXTENTs). |
1140 | * | |
1141 | * we do the calculation within the lower 32bit of the byte offsets, | |
1142 | * since we don't care for actual offset, but only check whether it | |
1143 | * would cross "activity log extent" boundaries. | |
1144 | * | |
1145 | * As long as the BIO is empty we have to allow at least one bvec, | |
1146 | * regardless of size and offset. so the resulting bio may still | |
1147 | * cross extent boundaries. those are dealt with (bio_split) in | |
2f58dcfc | 1148 | * drbd_make_request. |
b411b363 PR |
1149 | */ |
1150 | int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec) | |
1151 | { | |
1152 | struct drbd_conf *mdev = (struct drbd_conf *) q->queuedata; | |
1153 | unsigned int bio_offset = | |
1154 | (unsigned int)bvm->bi_sector << 9; /* 32 bit */ | |
1155 | unsigned int bio_size = bvm->bi_size; | |
1156 | int limit, backing_limit; | |
1157 | ||
1816a2b4 LE |
1158 | limit = DRBD_MAX_BIO_SIZE |
1159 | - ((bio_offset & (DRBD_MAX_BIO_SIZE-1)) + bio_size); | |
b411b363 PR |
1160 | if (limit < 0) |
1161 | limit = 0; | |
1162 | if (bio_size == 0) { | |
1163 | if (limit <= bvec->bv_len) | |
1164 | limit = bvec->bv_len; | |
1165 | } else if (limit && get_ldev(mdev)) { | |
1166 | struct request_queue * const b = | |
1167 | mdev->ldev->backing_bdev->bd_disk->queue; | |
a1c88d0d | 1168 | if (b->merge_bvec_fn) { |
b411b363 PR |
1169 | backing_limit = b->merge_bvec_fn(b, bvm, bvec); |
1170 | limit = min(limit, backing_limit); | |
1171 | } | |
1172 | put_ldev(mdev); | |
1173 | } | |
1174 | return limit; | |
1175 | } | |
7fde2be9 PR |
1176 | |
1177 | void request_timer_fn(unsigned long data) | |
1178 | { | |
1179 | struct drbd_conf *mdev = (struct drbd_conf *) data; | |
1180 | struct drbd_request *req; /* oldest request */ | |
1181 | struct list_head *le; | |
1182 | unsigned long et = 0; /* effective timeout = ko_count * timeout */ | |
1183 | ||
1184 | if (get_net_conf(mdev)) { | |
1185 | et = mdev->net_conf->timeout*HZ/10 * mdev->net_conf->ko_count; | |
1186 | put_net_conf(mdev); | |
1187 | } | |
1188 | if (!et || mdev->state.conn < C_WF_REPORT_PARAMS) | |
1189 | return; /* Recurring timer stopped */ | |
1190 | ||
1191 | spin_lock_irq(&mdev->req_lock); | |
1192 | le = &mdev->oldest_tle->requests; | |
1193 | if (list_empty(le)) { | |
1194 | spin_unlock_irq(&mdev->req_lock); | |
1195 | mod_timer(&mdev->request_timer, jiffies + et); | |
1196 | return; | |
1197 | } | |
1198 | ||
1199 | le = le->prev; | |
1200 | req = list_entry(le, struct drbd_request, tl_requests); | |
1201 | if (time_is_before_eq_jiffies(req->start_time + et)) { | |
1202 | if (req->rq_state & RQ_NET_PENDING) { | |
1203 | dev_warn(DEV, "Remote failed to finish a request within ko-count * timeout\n"); | |
1204 | _drbd_set_state(_NS(mdev, conn, C_TIMEOUT), CS_VERBOSE, NULL); | |
1205 | } else { | |
1206 | dev_warn(DEV, "Local backing block device frozen?\n"); | |
1207 | mod_timer(&mdev->request_timer, jiffies + et); | |
1208 | } | |
1209 | } else { | |
1210 | mod_timer(&mdev->request_timer, req->start_time + et); | |
1211 | } | |
1212 | ||
1213 | spin_unlock_irq(&mdev->req_lock); | |
1214 | } |