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Commit | Line | Data |
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b411b363 PR |
1 | /* |
2 | drbd_actlog.c | |
3 | ||
4 | This file is part of DRBD by Philipp Reisner and Lars Ellenberg. | |
5 | ||
6 | Copyright (C) 2003-2008, LINBIT Information Technologies GmbH. | |
7 | Copyright (C) 2003-2008, Philipp Reisner <philipp.reisner@linbit.com>. | |
8 | Copyright (C) 2003-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. | |
9 | ||
10 | drbd is free software; you can redistribute it and/or modify | |
11 | it under the terms of the GNU General Public License as published by | |
12 | the Free Software Foundation; either version 2, or (at your option) | |
13 | any later version. | |
14 | ||
15 | drbd is distributed in the hope that it will be useful, | |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | GNU General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU General Public License | |
21 | along with drbd; see the file COPYING. If not, write to | |
22 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
23 | ||
24 | */ | |
25 | ||
26 | #include <linux/slab.h> | |
7ad651b5 | 27 | #include <linux/crc32c.h> |
b411b363 | 28 | #include <linux/drbd.h> |
7ad651b5 | 29 | #include <linux/drbd_limits.h> |
b411b363 | 30 | #include "drbd_int.h" |
b411b363 | 31 | |
85f103d8 LE |
32 | |
33 | enum al_transaction_types { | |
34 | AL_TR_UPDATE = 0, | |
35 | AL_TR_INITIALIZED = 0xffff | |
36 | }; | |
7ad651b5 LE |
37 | /* all fields on disc in big endian */ |
38 | struct __packed al_transaction_on_disk { | |
39 | /* don't we all like magic */ | |
40 | __be32 magic; | |
41 | ||
42 | /* to identify the most recent transaction block | |
43 | * in the on disk ring buffer */ | |
44 | __be32 tr_number; | |
45 | ||
46 | /* checksum on the full 4k block, with this field set to 0. */ | |
47 | __be32 crc32c; | |
48 | ||
49 | /* type of transaction, special transaction types like: | |
85f103d8 LE |
50 | * purge-all, set-all-idle, set-all-active, ... to-be-defined |
51 | * see also enum al_transaction_types */ | |
7ad651b5 LE |
52 | __be16 transaction_type; |
53 | ||
54 | /* we currently allow only a few thousand extents, | |
55 | * so 16bit will be enough for the slot number. */ | |
56 | ||
57 | /* how many updates in this transaction */ | |
58 | __be16 n_updates; | |
59 | ||
60 | /* maximum slot number, "al-extents" in drbd.conf speak. | |
61 | * Having this in each transaction should make reconfiguration | |
62 | * of that parameter easier. */ | |
63 | __be16 context_size; | |
64 | ||
65 | /* slot number the context starts with */ | |
66 | __be16 context_start_slot_nr; | |
67 | ||
68 | /* Some reserved bytes. Expected usage is a 64bit counter of | |
69 | * sectors-written since device creation, and other data generation tag | |
70 | * supporting usage */ | |
71 | __be32 __reserved[4]; | |
72 | ||
73 | /* --- 36 byte used --- */ | |
74 | ||
75 | /* Reserve space for up to AL_UPDATES_PER_TRANSACTION changes | |
76 | * in one transaction, then use the remaining byte in the 4k block for | |
77 | * context information. "Flexible" number of updates per transaction | |
78 | * does not help, as we have to account for the case when all update | |
79 | * slots are used anyways, so it would only complicate code without | |
80 | * additional benefit. | |
81 | */ | |
82 | __be16 update_slot_nr[AL_UPDATES_PER_TRANSACTION]; | |
83 | ||
84 | /* but the extent number is 32bit, which at an extent size of 4 MiB | |
85 | * allows to cover device sizes of up to 2**54 Byte (16 PiB) */ | |
86 | __be32 update_extent_nr[AL_UPDATES_PER_TRANSACTION]; | |
87 | ||
88 | /* --- 420 bytes used (36 + 64*6) --- */ | |
89 | ||
90 | /* 4096 - 420 = 3676 = 919 * 4 */ | |
91 | __be32 context[AL_CONTEXT_PER_TRANSACTION]; | |
b411b363 PR |
92 | }; |
93 | ||
e37d2438 | 94 | void *drbd_md_get_buffer(struct drbd_device *device, const char *intent) |
cdfda633 PR |
95 | { |
96 | int r; | |
97 | ||
b30ab791 | 98 | wait_event(device->misc_wait, |
e37d2438 | 99 | (r = atomic_cmpxchg(&device->md_io.in_use, 0, 1)) == 0 || |
b30ab791 | 100 | device->state.disk <= D_FAILED); |
cdfda633 | 101 | |
e37d2438 LE |
102 | if (r) |
103 | return NULL; | |
104 | ||
105 | device->md_io.current_use = intent; | |
106 | device->md_io.start_jif = jiffies; | |
107 | device->md_io.submit_jif = device->md_io.start_jif - 1; | |
108 | return page_address(device->md_io.page); | |
cdfda633 PR |
109 | } |
110 | ||
b30ab791 | 111 | void drbd_md_put_buffer(struct drbd_device *device) |
cdfda633 | 112 | { |
e37d2438 | 113 | if (atomic_dec_and_test(&device->md_io.in_use)) |
b30ab791 | 114 | wake_up(&device->misc_wait); |
cdfda633 PR |
115 | } |
116 | ||
b30ab791 | 117 | void wait_until_done_or_force_detached(struct drbd_device *device, struct drbd_backing_dev *bdev, |
32db80f6 | 118 | unsigned int *done) |
cdfda633 | 119 | { |
32db80f6 PR |
120 | long dt; |
121 | ||
122 | rcu_read_lock(); | |
123 | dt = rcu_dereference(bdev->disk_conf)->disk_timeout; | |
124 | rcu_read_unlock(); | |
125 | dt = dt * HZ / 10; | |
126 | if (dt == 0) | |
127 | dt = MAX_SCHEDULE_TIMEOUT; | |
128 | ||
b30ab791 AG |
129 | dt = wait_event_timeout(device->misc_wait, |
130 | *done || test_bit(FORCE_DETACH, &device->flags), dt); | |
e34b677d | 131 | if (dt == 0) { |
d0180171 | 132 | drbd_err(device, "meta-data IO operation timed out\n"); |
b30ab791 | 133 | drbd_chk_io_error(device, 1, DRBD_FORCE_DETACH); |
e34b677d | 134 | } |
cdfda633 PR |
135 | } |
136 | ||
b30ab791 | 137 | static int _drbd_md_sync_page_io(struct drbd_device *device, |
b411b363 | 138 | struct drbd_backing_dev *bdev, |
bb3cc85e | 139 | sector_t sector, int op) |
b411b363 PR |
140 | { |
141 | struct bio *bio; | |
193cb00c LE |
142 | /* we do all our meta data IO in aligned 4k blocks. */ |
143 | const int size = 4096; | |
bb3cc85e | 144 | int err, op_flags = 0; |
b411b363 | 145 | |
b30ab791 AG |
146 | device->md_io.done = 0; |
147 | device->md_io.error = -ENODEV; | |
b411b363 | 148 | |
bb3cc85e | 149 | if ((op == REQ_OP_WRITE) && !test_bit(MD_NO_FUA, &device->flags)) |
28a8f0d3 | 150 | op_flags |= REQ_FUA | REQ_PREFLUSH; |
a2b80967 | 151 | op_flags |= REQ_SYNC; |
b411b363 | 152 | |
da4a75d2 | 153 | bio = bio_alloc_drbd(GFP_NOIO); |
74d46992 | 154 | bio_set_dev(bio, bdev->md_bdev); |
4f024f37 | 155 | bio->bi_iter.bi_sector = sector; |
ac29f403 | 156 | err = -EIO; |
193cb00c | 157 | if (bio_add_page(bio, device->md_io.page, size, 0) != size) |
b411b363 | 158 | goto out; |
e37d2438 | 159 | bio->bi_private = device; |
ed15b795 | 160 | bio->bi_end_io = drbd_md_endio; |
bb3cc85e | 161 | bio_set_op_attrs(bio, op, op_flags); |
b411b363 | 162 | |
bb3cc85e | 163 | if (op != REQ_OP_WRITE && device->state.disk == D_DISKLESS && device->ldev == NULL) |
c04ccaa6 LE |
164 | /* special case, drbd_md_read() during drbd_adm_attach(): no get_ldev */ |
165 | ; | |
b30ab791 | 166 | else if (!get_ldev_if_state(device, D_ATTACHING)) { |
ed15b795 | 167 | /* Corresponding put_ldev in drbd_md_endio() */ |
d0180171 | 168 | drbd_err(device, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n"); |
cdfda633 PR |
169 | err = -ENODEV; |
170 | goto out; | |
171 | } | |
172 | ||
173 | bio_get(bio); /* one bio_put() is in the completion handler */ | |
e37d2438 LE |
174 | atomic_inc(&device->md_io.in_use); /* drbd_md_put_buffer() is in the completion handler */ |
175 | device->md_io.submit_jif = jiffies; | |
bb3cc85e | 176 | if (drbd_insert_fault(device, (op == REQ_OP_WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) |
4246a0b6 | 177 | bio_io_error(bio); |
b411b363 | 178 | else |
4e49ea4a | 179 | submit_bio(bio); |
b30ab791 | 180 | wait_until_done_or_force_detached(device, bdev, &device->md_io.done); |
4e4cbee9 | 181 | if (!bio->bi_status) |
b30ab791 | 182 | err = device->md_io.error; |
b411b363 | 183 | |
b411b363 PR |
184 | out: |
185 | bio_put(bio); | |
ac29f403 | 186 | return err; |
b411b363 PR |
187 | } |
188 | ||
b30ab791 | 189 | int drbd_md_sync_page_io(struct drbd_device *device, struct drbd_backing_dev *bdev, |
bb3cc85e | 190 | sector_t sector, int op) |
b411b363 | 191 | { |
3fbf4d21 | 192 | int err; |
e37d2438 | 193 | D_ASSERT(device, atomic_read(&device->md_io.in_use) == 1); |
b411b363 PR |
194 | |
195 | BUG_ON(!bdev->md_bdev); | |
196 | ||
e4d7d6f4 | 197 | dynamic_drbd_dbg(device, "meta_data io: %s [%d]:%s(,%llus,%s) %pS\n", |
7ad651b5 | 198 | current->comm, current->pid, __func__, |
bb3cc85e | 199 | (unsigned long long)sector, (op == REQ_OP_WRITE) ? "WRITE" : "READ", |
c04ccaa6 | 200 | (void*)_RET_IP_ ); |
b411b363 PR |
201 | |
202 | if (sector < drbd_md_first_sector(bdev) || | |
7ad651b5 | 203 | sector + 7 > drbd_md_last_sector(bdev)) |
d0180171 | 204 | drbd_alert(device, "%s [%d]:%s(,%llus,%s) out of range md access!\n", |
b411b363 | 205 | current->comm, current->pid, __func__, |
bb3cc85e MC |
206 | (unsigned long long)sector, |
207 | (op == REQ_OP_WRITE) ? "WRITE" : "READ"); | |
b411b363 | 208 | |
bb3cc85e | 209 | err = _drbd_md_sync_page_io(device, bdev, sector, op); |
3fbf4d21 | 210 | if (err) { |
d0180171 | 211 | drbd_err(device, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n", |
bb3cc85e MC |
212 | (unsigned long long)sector, |
213 | (op == REQ_OP_WRITE) ? "WRITE" : "READ", err); | |
b411b363 | 214 | } |
3fbf4d21 | 215 | return err; |
b411b363 PR |
216 | } |
217 | ||
b30ab791 | 218 | static struct bm_extent *find_active_resync_extent(struct drbd_device *device, unsigned int enr) |
b411b363 | 219 | { |
b411b363 | 220 | struct lc_element *tmp; |
b30ab791 | 221 | tmp = lc_find(device->resync, enr/AL_EXT_PER_BM_SECT); |
b411b363 PR |
222 | if (unlikely(tmp != NULL)) { |
223 | struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); | |
6c3c4355 LE |
224 | if (test_bit(BME_NO_WRITES, &bm_ext->flags)) |
225 | return bm_ext; | |
b411b363 | 226 | } |
6c3c4355 LE |
227 | return NULL; |
228 | } | |
229 | ||
b30ab791 | 230 | static struct lc_element *_al_get(struct drbd_device *device, unsigned int enr, bool nonblock) |
6c3c4355 LE |
231 | { |
232 | struct lc_element *al_ext; | |
233 | struct bm_extent *bm_ext; | |
234 | int wake; | |
235 | ||
b30ab791 AG |
236 | spin_lock_irq(&device->al_lock); |
237 | bm_ext = find_active_resync_extent(device, enr); | |
6c3c4355 LE |
238 | if (bm_ext) { |
239 | wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags); | |
b30ab791 | 240 | spin_unlock_irq(&device->al_lock); |
6c3c4355 | 241 | if (wake) |
b30ab791 | 242 | wake_up(&device->al_wait); |
6c3c4355 LE |
243 | return NULL; |
244 | } | |
245 | if (nonblock) | |
b30ab791 | 246 | al_ext = lc_try_get(device->act_log, enr); |
6c3c4355 | 247 | else |
b30ab791 AG |
248 | al_ext = lc_get(device->act_log, enr); |
249 | spin_unlock_irq(&device->al_lock); | |
b411b363 PR |
250 | return al_ext; |
251 | } | |
252 | ||
b30ab791 | 253 | bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i) |
b411b363 | 254 | { |
7726547e LE |
255 | /* for bios crossing activity log extent boundaries, |
256 | * we may need to activate two extents in one go */ | |
e15766e9 | 257 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); |
81a3537a | 258 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
7dc1d67f | 259 | |
505675f9 | 260 | D_ASSERT(device, first <= last); |
0b0ba1ef | 261 | D_ASSERT(device, atomic_read(&device->local_cnt) > 0); |
b5bc8e08 LE |
262 | |
263 | /* FIXME figure out a fast path for bios crossing AL extent boundaries */ | |
264 | if (first != last) | |
265 | return false; | |
266 | ||
b30ab791 | 267 | return _al_get(device, first, true); |
b5bc8e08 | 268 | } |
56392d2f | 269 | |
b30ab791 | 270 | bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i) |
b5bc8e08 LE |
271 | { |
272 | /* for bios crossing activity log extent boundaries, | |
273 | * we may need to activate two extents in one go */ | |
274 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); | |
275 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); | |
276 | unsigned enr; | |
277 | bool need_transaction = false; | |
b411b363 | 278 | |
0b0ba1ef AG |
279 | D_ASSERT(device, first <= last); |
280 | D_ASSERT(device, atomic_read(&device->local_cnt) > 0); | |
b411b363 | 281 | |
ebfd5d8f LE |
282 | for (enr = first; enr <= last; enr++) { |
283 | struct lc_element *al_ext; | |
b30ab791 AG |
284 | wait_event(device->al_wait, |
285 | (al_ext = _al_get(device, enr, false)) != NULL); | |
ebfd5d8f LE |
286 | if (al_ext->lc_number != enr) |
287 | need_transaction = true; | |
288 | } | |
b5bc8e08 LE |
289 | return need_transaction; |
290 | } | |
291 | ||
603ee2c8 LE |
292 | #if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT) |
293 | /* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT | |
294 | * are still coupled, or assume too much about their relation. | |
295 | * Code below will not work if this is violated. | |
296 | * Will be cleaned up with some followup patch. | |
297 | */ | |
298 | # error FIXME | |
299 | #endif | |
300 | ||
301 | static unsigned int al_extent_to_bm_page(unsigned int al_enr) | |
302 | { | |
303 | return al_enr >> | |
304 | /* bit to page */ | |
305 | ((PAGE_SHIFT + 3) - | |
306 | /* al extent number to bit */ | |
307 | (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)); | |
308 | } | |
309 | ||
310 | static sector_t al_tr_number_to_on_disk_sector(struct drbd_device *device) | |
311 | { | |
312 | const unsigned int stripes = device->ldev->md.al_stripes; | |
313 | const unsigned int stripe_size_4kB = device->ldev->md.al_stripe_size_4k; | |
314 | ||
315 | /* transaction number, modulo on-disk ring buffer wrap around */ | |
316 | unsigned int t = device->al_tr_number % (device->ldev->md.al_size_4k); | |
317 | ||
318 | /* ... to aligned 4k on disk block */ | |
319 | t = ((t % stripes) * stripe_size_4kB) + t/stripes; | |
320 | ||
321 | /* ... to 512 byte sector in activity log */ | |
322 | t *= 8; | |
323 | ||
324 | /* ... plus offset to the on disk position */ | |
325 | return device->ldev->md.md_offset + device->ldev->md.al_offset + t; | |
326 | } | |
327 | ||
328 | static int __al_write_transaction(struct drbd_device *device, struct al_transaction_on_disk *buffer) | |
329 | { | |
330 | struct lc_element *e; | |
331 | sector_t sector; | |
332 | int i, mx; | |
333 | unsigned extent_nr; | |
334 | unsigned crc = 0; | |
335 | int err = 0; | |
336 | ||
337 | memset(buffer, 0, sizeof(*buffer)); | |
338 | buffer->magic = cpu_to_be32(DRBD_AL_MAGIC); | |
339 | buffer->tr_number = cpu_to_be32(device->al_tr_number); | |
340 | ||
341 | i = 0; | |
342 | ||
27ea1d87 LE |
343 | drbd_bm_reset_al_hints(device); |
344 | ||
603ee2c8 LE |
345 | /* Even though no one can start to change this list |
346 | * once we set the LC_LOCKED -- from drbd_al_begin_io(), | |
347 | * lc_try_lock_for_transaction() --, someone may still | |
348 | * be in the process of changing it. */ | |
349 | spin_lock_irq(&device->al_lock); | |
350 | list_for_each_entry(e, &device->act_log->to_be_changed, list) { | |
351 | if (i == AL_UPDATES_PER_TRANSACTION) { | |
352 | i++; | |
353 | break; | |
354 | } | |
355 | buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index); | |
356 | buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number); | |
357 | if (e->lc_number != LC_FREE) | |
358 | drbd_bm_mark_for_writeout(device, | |
359 | al_extent_to_bm_page(e->lc_number)); | |
360 | i++; | |
361 | } | |
362 | spin_unlock_irq(&device->al_lock); | |
363 | BUG_ON(i > AL_UPDATES_PER_TRANSACTION); | |
364 | ||
365 | buffer->n_updates = cpu_to_be16(i); | |
366 | for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) { | |
367 | buffer->update_slot_nr[i] = cpu_to_be16(-1); | |
368 | buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE); | |
369 | } | |
370 | ||
371 | buffer->context_size = cpu_to_be16(device->act_log->nr_elements); | |
372 | buffer->context_start_slot_nr = cpu_to_be16(device->al_tr_cycle); | |
373 | ||
374 | mx = min_t(int, AL_CONTEXT_PER_TRANSACTION, | |
375 | device->act_log->nr_elements - device->al_tr_cycle); | |
376 | for (i = 0; i < mx; i++) { | |
377 | unsigned idx = device->al_tr_cycle + i; | |
378 | extent_nr = lc_element_by_index(device->act_log, idx)->lc_number; | |
379 | buffer->context[i] = cpu_to_be32(extent_nr); | |
380 | } | |
381 | for (; i < AL_CONTEXT_PER_TRANSACTION; i++) | |
382 | buffer->context[i] = cpu_to_be32(LC_FREE); | |
383 | ||
384 | device->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION; | |
385 | if (device->al_tr_cycle >= device->act_log->nr_elements) | |
386 | device->al_tr_cycle = 0; | |
387 | ||
388 | sector = al_tr_number_to_on_disk_sector(device); | |
389 | ||
390 | crc = crc32c(0, buffer, 4096); | |
391 | buffer->crc32c = cpu_to_be32(crc); | |
392 | ||
393 | if (drbd_bm_write_hinted(device)) | |
394 | err = -EIO; | |
395 | else { | |
396 | bool write_al_updates; | |
397 | rcu_read_lock(); | |
398 | write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates; | |
399 | rcu_read_unlock(); | |
400 | if (write_al_updates) { | |
401 | if (drbd_md_sync_page_io(device, device->ldev, sector, WRITE)) { | |
402 | err = -EIO; | |
403 | drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR); | |
404 | } else { | |
405 | device->al_tr_number++; | |
406 | device->al_writ_cnt++; | |
407 | } | |
408 | } | |
409 | } | |
410 | ||
411 | return err; | |
412 | } | |
413 | ||
414 | static int al_write_transaction(struct drbd_device *device) | |
415 | { | |
416 | struct al_transaction_on_disk *buffer; | |
417 | int err; | |
418 | ||
419 | if (!get_ldev(device)) { | |
420 | drbd_err(device, "disk is %s, cannot start al transaction\n", | |
421 | drbd_disk_str(device->state.disk)); | |
422 | return -EIO; | |
423 | } | |
424 | ||
425 | /* The bitmap write may have failed, causing a state change. */ | |
426 | if (device->state.disk < D_INCONSISTENT) { | |
427 | drbd_err(device, | |
428 | "disk is %s, cannot write al transaction\n", | |
429 | drbd_disk_str(device->state.disk)); | |
430 | put_ldev(device); | |
431 | return -EIO; | |
432 | } | |
433 | ||
434 | /* protects md_io_buffer, al_tr_cycle, ... */ | |
435 | buffer = drbd_md_get_buffer(device, __func__); | |
436 | if (!buffer) { | |
437 | drbd_err(device, "disk failed while waiting for md_io buffer\n"); | |
438 | put_ldev(device); | |
439 | return -ENODEV; | |
440 | } | |
441 | ||
442 | err = __al_write_transaction(device, buffer); | |
443 | ||
444 | drbd_md_put_buffer(device); | |
445 | put_ldev(device); | |
446 | ||
447 | return err; | |
448 | } | |
449 | ||
b5bc8e08 | 450 | |
4dd726f0 | 451 | void drbd_al_begin_io_commit(struct drbd_device *device) |
b5bc8e08 LE |
452 | { |
453 | bool locked = false; | |
ebfd5d8f | 454 | |
7dc1d67f LE |
455 | /* Serialize multiple transactions. |
456 | * This uses test_and_set_bit, memory barrier is implicit. | |
457 | */ | |
b30ab791 AG |
458 | wait_event(device->al_wait, |
459 | device->act_log->pending_changes == 0 || | |
460 | (locked = lc_try_lock_for_transaction(device->act_log))); | |
7dc1d67f LE |
461 | |
462 | if (locked) { | |
7ad651b5 LE |
463 | /* Double check: it may have been committed by someone else, |
464 | * while we have been waiting for the lock. */ | |
b30ab791 | 465 | if (device->act_log->pending_changes) { |
9a51ab1c PR |
466 | bool write_al_updates; |
467 | ||
468 | rcu_read_lock(); | |
b30ab791 | 469 | write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates; |
9a51ab1c PR |
470 | rcu_read_unlock(); |
471 | ||
b5bc8e08 | 472 | if (write_al_updates) |
4dd726f0 | 473 | al_write_transaction(device); |
b30ab791 | 474 | spin_lock_irq(&device->al_lock); |
7ad651b5 | 475 | /* FIXME |
1b7ab15b | 476 | if (err) |
7ad651b5 LE |
477 | we need an "lc_cancel" here; |
478 | */ | |
b30ab791 AG |
479 | lc_committed(device->act_log); |
480 | spin_unlock_irq(&device->al_lock); | |
7ad651b5 | 481 | } |
b30ab791 AG |
482 | lc_unlock(device->act_log); |
483 | wake_up(&device->al_wait); | |
b411b363 PR |
484 | } |
485 | } | |
486 | ||
b5bc8e08 LE |
487 | /* |
488 | * @delegate: delegate activity log I/O to the worker thread | |
489 | */ | |
4dd726f0 | 490 | void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i) |
b5bc8e08 | 491 | { |
b30ab791 | 492 | if (drbd_al_begin_io_prepare(device, i)) |
4dd726f0 | 493 | drbd_al_begin_io_commit(device); |
b5bc8e08 LE |
494 | } |
495 | ||
b30ab791 | 496 | int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i) |
08a1ddab | 497 | { |
b30ab791 | 498 | struct lru_cache *al = device->act_log; |
08a1ddab LE |
499 | /* for bios crossing activity log extent boundaries, |
500 | * we may need to activate two extents in one go */ | |
501 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); | |
502 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); | |
503 | unsigned nr_al_extents; | |
504 | unsigned available_update_slots; | |
505 | unsigned enr; | |
506 | ||
0b0ba1ef | 507 | D_ASSERT(device, first <= last); |
08a1ddab LE |
508 | |
509 | nr_al_extents = 1 + last - first; /* worst case: all touched extends are cold. */ | |
510 | available_update_slots = min(al->nr_elements - al->used, | |
511 | al->max_pending_changes - al->pending_changes); | |
512 | ||
513 | /* We want all necessary updates for a given request within the same transaction | |
514 | * We could first check how many updates are *actually* needed, | |
515 | * and use that instead of the worst-case nr_al_extents */ | |
f5b90b6b LE |
516 | if (available_update_slots < nr_al_extents) { |
517 | /* Too many activity log extents are currently "hot". | |
518 | * | |
519 | * If we have accumulated pending changes already, | |
520 | * we made progress. | |
521 | * | |
522 | * If we cannot get even a single pending change through, | |
523 | * stop the fast path until we made some progress, | |
524 | * or requests to "cold" extents could be starved. */ | |
525 | if (!al->pending_changes) | |
526 | __set_bit(__LC_STARVING, &device->act_log->flags); | |
527 | return -ENOBUFS; | |
528 | } | |
08a1ddab LE |
529 | |
530 | /* Is resync active in this area? */ | |
531 | for (enr = first; enr <= last; enr++) { | |
532 | struct lc_element *tmp; | |
b30ab791 | 533 | tmp = lc_find(device->resync, enr/AL_EXT_PER_BM_SECT); |
08a1ddab LE |
534 | if (unlikely(tmp != NULL)) { |
535 | struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); | |
536 | if (test_bit(BME_NO_WRITES, &bm_ext->flags)) { | |
0b6ef416 | 537 | if (!test_and_set_bit(BME_PRIORITY, &bm_ext->flags)) |
08a1ddab LE |
538 | return -EBUSY; |
539 | return -EWOULDBLOCK; | |
540 | } | |
541 | } | |
542 | } | |
543 | ||
544 | /* Checkout the refcounts. | |
545 | * Given that we checked for available elements and update slots above, | |
546 | * this has to be successful. */ | |
547 | for (enr = first; enr <= last; enr++) { | |
548 | struct lc_element *al_ext; | |
b30ab791 | 549 | al_ext = lc_get_cumulative(device->act_log, enr); |
08a1ddab | 550 | if (!al_ext) |
d0180171 | 551 | drbd_info(device, "LOGIC BUG for enr=%u\n", enr); |
08a1ddab LE |
552 | } |
553 | return 0; | |
554 | } | |
555 | ||
b30ab791 | 556 | void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i) |
b411b363 | 557 | { |
e15766e9 LE |
558 | /* for bios crossing activity log extent boundaries, |
559 | * we may need to activate two extents in one go */ | |
560 | unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); | |
81a3537a | 561 | unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); |
e15766e9 | 562 | unsigned enr; |
b411b363 PR |
563 | struct lc_element *extent; |
564 | unsigned long flags; | |
565 | ||
0b0ba1ef | 566 | D_ASSERT(device, first <= last); |
b30ab791 | 567 | spin_lock_irqsave(&device->al_lock, flags); |
b411b363 | 568 | |
e15766e9 | 569 | for (enr = first; enr <= last; enr++) { |
b30ab791 | 570 | extent = lc_find(device->act_log, enr); |
e15766e9 | 571 | if (!extent) { |
d0180171 | 572 | drbd_err(device, "al_complete_io() called on inactive extent %u\n", enr); |
e15766e9 LE |
573 | continue; |
574 | } | |
b30ab791 | 575 | lc_put(device->act_log, extent); |
b411b363 | 576 | } |
b30ab791 AG |
577 | spin_unlock_irqrestore(&device->al_lock, flags); |
578 | wake_up(&device->al_wait); | |
b411b363 PR |
579 | } |
580 | ||
b30ab791 | 581 | static int _try_lc_del(struct drbd_device *device, struct lc_element *al_ext) |
b411b363 PR |
582 | { |
583 | int rv; | |
584 | ||
b30ab791 | 585 | spin_lock_irq(&device->al_lock); |
b411b363 PR |
586 | rv = (al_ext->refcnt == 0); |
587 | if (likely(rv)) | |
b30ab791 AG |
588 | lc_del(device->act_log, al_ext); |
589 | spin_unlock_irq(&device->al_lock); | |
b411b363 PR |
590 | |
591 | return rv; | |
592 | } | |
593 | ||
594 | /** | |
595 | * drbd_al_shrink() - Removes all active extents form the activity log | |
b30ab791 | 596 | * @device: DRBD device. |
b411b363 PR |
597 | * |
598 | * Removes all active extents form the activity log, waiting until | |
599 | * the reference count of each entry dropped to 0 first, of course. | |
600 | * | |
b30ab791 | 601 | * You need to lock device->act_log with lc_try_lock() / lc_unlock() |
b411b363 | 602 | */ |
b30ab791 | 603 | void drbd_al_shrink(struct drbd_device *device) |
b411b363 PR |
604 | { |
605 | struct lc_element *al_ext; | |
606 | int i; | |
607 | ||
0b0ba1ef | 608 | D_ASSERT(device, test_bit(__LC_LOCKED, &device->act_log->flags)); |
b411b363 | 609 | |
b30ab791 AG |
610 | for (i = 0; i < device->act_log->nr_elements; i++) { |
611 | al_ext = lc_element_by_index(device->act_log, i); | |
b411b363 PR |
612 | if (al_ext->lc_number == LC_FREE) |
613 | continue; | |
b30ab791 | 614 | wait_event(device->al_wait, _try_lc_del(device, al_ext)); |
b411b363 PR |
615 | } |
616 | ||
b30ab791 | 617 | wake_up(&device->al_wait); |
b411b363 PR |
618 | } |
619 | ||
5f7c0124 | 620 | int drbd_al_initialize(struct drbd_device *device, void *buffer) |
d752b269 PR |
621 | { |
622 | struct al_transaction_on_disk *al = buffer; | |
b30ab791 | 623 | struct drbd_md *md = &device->ldev->md; |
d752b269 PR |
624 | int al_size_4k = md->al_stripes * md->al_stripe_size_4k; |
625 | int i; | |
626 | ||
5f7c0124 LE |
627 | __al_write_transaction(device, al); |
628 | /* There may or may not have been a pending transaction. */ | |
629 | spin_lock_irq(&device->al_lock); | |
630 | lc_committed(device->act_log); | |
631 | spin_unlock_irq(&device->al_lock); | |
d752b269 | 632 | |
5f7c0124 LE |
633 | /* The rest of the transactions will have an empty "updates" list, and |
634 | * are written out only to provide the context, and to initialize the | |
635 | * on-disk ring buffer. */ | |
636 | for (i = 1; i < al_size_4k; i++) { | |
637 | int err = __al_write_transaction(device, al); | |
d752b269 PR |
638 | if (err) |
639 | return err; | |
640 | } | |
641 | return 0; | |
642 | } | |
643 | ||
5ab7d2c0 LE |
644 | static const char *drbd_change_sync_fname[] = { |
645 | [RECORD_RS_FAILED] = "drbd_rs_failed_io", | |
646 | [SET_IN_SYNC] = "drbd_set_in_sync", | |
647 | [SET_OUT_OF_SYNC] = "drbd_set_out_of_sync" | |
648 | }; | |
649 | ||
b411b363 PR |
650 | /* ATTENTION. The AL's extents are 4MB each, while the extents in the |
651 | * resync LRU-cache are 16MB each. | |
652 | * The caller of this function has to hold an get_ldev() reference. | |
653 | * | |
5ab7d2c0 LE |
654 | * Adjusts the caching members ->rs_left (success) or ->rs_failed (!success), |
655 | * potentially pulling in (and recounting the corresponding bits) | |
656 | * this resync extent into the resync extent lru cache. | |
657 | * | |
658 | * Returns whether all bits have been cleared for this resync extent, | |
659 | * precisely: (rs_left <= rs_failed) | |
660 | * | |
b411b363 PR |
661 | * TODO will be obsoleted once we have a caching lru of the on disk bitmap |
662 | */ | |
5ab7d2c0 LE |
663 | static bool update_rs_extent(struct drbd_device *device, |
664 | unsigned int enr, int count, | |
665 | enum update_sync_bits_mode mode) | |
b411b363 PR |
666 | { |
667 | struct lc_element *e; | |
b411b363 | 668 | |
0b0ba1ef | 669 | D_ASSERT(device, atomic_read(&device->local_cnt)); |
b411b363 | 670 | |
5ab7d2c0 LE |
671 | /* When setting out-of-sync bits, |
672 | * we don't need it cached (lc_find). | |
673 | * But if it is present in the cache, | |
674 | * we should update the cached bit count. | |
675 | * Otherwise, that extent should be in the resync extent lru cache | |
676 | * already -- or we want to pull it in if necessary -- (lc_get), | |
677 | * then update and check rs_left and rs_failed. */ | |
678 | if (mode == SET_OUT_OF_SYNC) | |
679 | e = lc_find(device->resync, enr); | |
680 | else | |
681 | e = lc_get(device->resync, enr); | |
b411b363 PR |
682 | if (e) { |
683 | struct bm_extent *ext = lc_entry(e, struct bm_extent, lce); | |
684 | if (ext->lce.lc_number == enr) { | |
5ab7d2c0 | 685 | if (mode == SET_IN_SYNC) |
b411b363 | 686 | ext->rs_left -= count; |
5ab7d2c0 LE |
687 | else if (mode == SET_OUT_OF_SYNC) |
688 | ext->rs_left += count; | |
b411b363 PR |
689 | else |
690 | ext->rs_failed += count; | |
691 | if (ext->rs_left < ext->rs_failed) { | |
5ab7d2c0 | 692 | drbd_warn(device, "BAD! enr=%u rs_left=%d " |
975b2979 | 693 | "rs_failed=%d count=%d cstate=%s\n", |
b411b363 | 694 | ext->lce.lc_number, ext->rs_left, |
975b2979 | 695 | ext->rs_failed, count, |
b30ab791 | 696 | drbd_conn_str(device->state.conn)); |
975b2979 PR |
697 | |
698 | /* We don't expect to be able to clear more bits | |
699 | * than have been set when we originally counted | |
700 | * the set bits to cache that value in ext->rs_left. | |
701 | * Whatever the reason (disconnect during resync, | |
702 | * delayed local completion of an application write), | |
703 | * try to fix it up by recounting here. */ | |
b30ab791 | 704 | ext->rs_left = drbd_bm_e_weight(device, enr); |
b411b363 PR |
705 | } |
706 | } else { | |
707 | /* Normally this element should be in the cache, | |
708 | * since drbd_rs_begin_io() pulled it already in. | |
709 | * | |
710 | * But maybe an application write finished, and we set | |
711 | * something outside the resync lru_cache in sync. | |
712 | */ | |
b30ab791 | 713 | int rs_left = drbd_bm_e_weight(device, enr); |
b411b363 | 714 | if (ext->flags != 0) { |
d0180171 | 715 | drbd_warn(device, "changing resync lce: %d[%u;%02lx]" |
b411b363 PR |
716 | " -> %d[%u;00]\n", |
717 | ext->lce.lc_number, ext->rs_left, | |
718 | ext->flags, enr, rs_left); | |
719 | ext->flags = 0; | |
720 | } | |
721 | if (ext->rs_failed) { | |
d0180171 | 722 | drbd_warn(device, "Kicking resync_lru element enr=%u " |
b411b363 PR |
723 | "out with rs_failed=%d\n", |
724 | ext->lce.lc_number, ext->rs_failed); | |
b411b363 PR |
725 | } |
726 | ext->rs_left = rs_left; | |
5ab7d2c0 | 727 | ext->rs_failed = (mode == RECORD_RS_FAILED) ? count : 0; |
46a15bc3 LE |
728 | /* we don't keep a persistent log of the resync lru, |
729 | * we can commit any change right away. */ | |
b30ab791 | 730 | lc_committed(device->resync); |
b411b363 | 731 | } |
5ab7d2c0 LE |
732 | if (mode != SET_OUT_OF_SYNC) |
733 | lc_put(device->resync, &ext->lce); | |
b411b363 PR |
734 | /* no race, we are within the al_lock! */ |
735 | ||
5ab7d2c0 | 736 | if (ext->rs_left <= ext->rs_failed) { |
b411b363 | 737 | ext->rs_failed = 0; |
5ab7d2c0 | 738 | return true; |
b411b363 | 739 | } |
5ab7d2c0 LE |
740 | } else if (mode != SET_OUT_OF_SYNC) { |
741 | /* be quiet if lc_find() did not find it. */ | |
d0180171 | 742 | drbd_err(device, "lc_get() failed! locked=%d/%d flags=%lu\n", |
b30ab791 AG |
743 | device->resync_locked, |
744 | device->resync->nr_elements, | |
745 | device->resync->flags); | |
b411b363 | 746 | } |
5ab7d2c0 | 747 | return false; |
b411b363 PR |
748 | } |
749 | ||
b30ab791 | 750 | void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go) |
c6ea14df LE |
751 | { |
752 | unsigned long now = jiffies; | |
b30ab791 AG |
753 | unsigned long last = device->rs_mark_time[device->rs_last_mark]; |
754 | int next = (device->rs_last_mark + 1) % DRBD_SYNC_MARKS; | |
c6ea14df | 755 | if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) { |
b30ab791 AG |
756 | if (device->rs_mark_left[device->rs_last_mark] != still_to_go && |
757 | device->state.conn != C_PAUSED_SYNC_T && | |
758 | device->state.conn != C_PAUSED_SYNC_S) { | |
759 | device->rs_mark_time[next] = now; | |
760 | device->rs_mark_left[next] = still_to_go; | |
761 | device->rs_last_mark = next; | |
c6ea14df LE |
762 | } |
763 | } | |
764 | } | |
765 | ||
5ab7d2c0 LE |
766 | /* It is called lazy update, so don't do write-out too often. */ |
767 | static bool lazy_bitmap_update_due(struct drbd_device *device) | |
b411b363 | 768 | { |
5ab7d2c0 LE |
769 | return time_after(jiffies, device->rs_last_bcast + 2*HZ); |
770 | } | |
b411b363 | 771 | |
5ab7d2c0 LE |
772 | static void maybe_schedule_on_disk_bitmap_update(struct drbd_device *device, bool rs_done) |
773 | { | |
5052fee2 LE |
774 | if (rs_done) { |
775 | struct drbd_connection *connection = first_peer_device(device)->connection; | |
776 | if (connection->agreed_pro_version <= 95 || | |
777 | is_sync_target_state(device->state.conn)) | |
778 | set_bit(RS_DONE, &device->flags); | |
779 | /* and also set RS_PROGRESS below */ | |
780 | ||
781 | /* Else: rather wait for explicit notification via receive_state, | |
782 | * to avoid uuids-rotated-too-fast causing full resync | |
783 | * in next handshake, in case the replication link breaks | |
784 | * at the most unfortunate time... */ | |
785 | } else if (!lazy_bitmap_update_due(device)) | |
b411b363 | 786 | return; |
518a4d53 | 787 | |
e334f550 | 788 | drbd_device_post_work(device, RS_PROGRESS); |
5ab7d2c0 | 789 | } |
b411b363 | 790 | |
5ab7d2c0 LE |
791 | static int update_sync_bits(struct drbd_device *device, |
792 | unsigned long sbnr, unsigned long ebnr, | |
793 | enum update_sync_bits_mode mode) | |
794 | { | |
b411b363 | 795 | /* |
5ab7d2c0 LE |
796 | * We keep a count of set bits per resync-extent in the ->rs_left |
797 | * caching member, so we need to loop and work within the resync extent | |
798 | * alignment. Typically this loop will execute exactly once. | |
b411b363 | 799 | */ |
5ab7d2c0 LE |
800 | unsigned long flags; |
801 | unsigned long count = 0; | |
802 | unsigned int cleared = 0; | |
803 | while (sbnr <= ebnr) { | |
804 | /* set temporary boundary bit number to last bit number within | |
805 | * the resync extent of the current start bit number, | |
806 | * but cap at provided end bit number */ | |
807 | unsigned long tbnr = min(ebnr, sbnr | BM_BLOCKS_PER_BM_EXT_MASK); | |
808 | unsigned long c; | |
809 | ||
810 | if (mode == RECORD_RS_FAILED) | |
811 | /* Only called from drbd_rs_failed_io(), bits | |
812 | * supposedly still set. Recount, maybe some | |
813 | * of the bits have been successfully cleared | |
814 | * by application IO meanwhile. | |
815 | */ | |
816 | c = drbd_bm_count_bits(device, sbnr, tbnr); | |
817 | else if (mode == SET_IN_SYNC) | |
818 | c = drbd_bm_clear_bits(device, sbnr, tbnr); | |
819 | else /* if (mode == SET_OUT_OF_SYNC) */ | |
820 | c = drbd_bm_set_bits(device, sbnr, tbnr); | |
821 | ||
822 | if (c) { | |
823 | spin_lock_irqsave(&device->al_lock, flags); | |
824 | cleared += update_rs_extent(device, BM_BIT_TO_EXT(sbnr), c, mode); | |
825 | spin_unlock_irqrestore(&device->al_lock, flags); | |
826 | count += c; | |
827 | } | |
828 | sbnr = tbnr + 1; | |
b411b363 | 829 | } |
5ab7d2c0 LE |
830 | if (count) { |
831 | if (mode == SET_IN_SYNC) { | |
832 | unsigned long still_to_go = drbd_bm_total_weight(device); | |
833 | bool rs_is_done = (still_to_go <= device->rs_failed); | |
834 | drbd_advance_rs_marks(device, still_to_go); | |
835 | if (cleared || rs_is_done) | |
836 | maybe_schedule_on_disk_bitmap_update(device, rs_is_done); | |
837 | } else if (mode == RECORD_RS_FAILED) | |
838 | device->rs_failed += count; | |
b30ab791 | 839 | wake_up(&device->al_wait); |
5ab7d2c0 LE |
840 | } |
841 | return count; | |
b411b363 PR |
842 | } |
843 | ||
9104d31a LE |
844 | static bool plausible_request_size(int size) |
845 | { | |
846 | return size > 0 | |
847 | && size <= DRBD_MAX_BATCH_BIO_SIZE | |
848 | && IS_ALIGNED(size, 512); | |
849 | } | |
850 | ||
5ab7d2c0 LE |
851 | /* clear the bit corresponding to the piece of storage in question: |
852 | * size byte of data starting from sector. Only clear a bits of the affected | |
853 | * one ore more _aligned_ BM_BLOCK_SIZE blocks. | |
854 | * | |
855 | * called by worker on C_SYNC_TARGET and receiver on SyncSource. | |
b411b363 | 856 | * |
b411b363 | 857 | */ |
5ab7d2c0 | 858 | int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size, |
179e20b8 | 859 | enum update_sync_bits_mode mode) |
b411b363 | 860 | { |
5ab7d2c0 LE |
861 | /* Is called from worker and receiver context _only_ */ |
862 | unsigned long sbnr, ebnr, lbnr; | |
863 | unsigned long count = 0; | |
b411b363 | 864 | sector_t esector, nr_sectors; |
b411b363 | 865 | |
28a8f0d3 | 866 | /* This would be an empty REQ_PREFLUSH, be silent. */ |
5ab7d2c0 | 867 | if ((mode == SET_OUT_OF_SYNC) && size == 0) |
81a3537a LE |
868 | return 0; |
869 | ||
9104d31a | 870 | if (!plausible_request_size(size)) { |
5ab7d2c0 LE |
871 | drbd_err(device, "%s: sector=%llus size=%d nonsense!\n", |
872 | drbd_change_sync_fname[mode], | |
873 | (unsigned long long)sector, size); | |
73a01a18 | 874 | return 0; |
b411b363 PR |
875 | } |
876 | ||
b30ab791 | 877 | if (!get_ldev(device)) |
5ab7d2c0 | 878 | return 0; /* no disk, no metadata, no bitmap to manipulate bits in */ |
b411b363 | 879 | |
b30ab791 | 880 | nr_sectors = drbd_get_capacity(device->this_bdev); |
b411b363 PR |
881 | esector = sector + (size >> 9) - 1; |
882 | ||
841ce241 | 883 | if (!expect(sector < nr_sectors)) |
b411b363 | 884 | goto out; |
841ce241 AG |
885 | if (!expect(esector < nr_sectors)) |
886 | esector = nr_sectors - 1; | |
b411b363 | 887 | |
5ab7d2c0 | 888 | lbnr = BM_SECT_TO_BIT(nr_sectors-1); |
b411b363 | 889 | |
5ab7d2c0 LE |
890 | if (mode == SET_IN_SYNC) { |
891 | /* Round up start sector, round down end sector. We make sure | |
892 | * we only clear full, aligned, BM_BLOCK_SIZE blocks. */ | |
893 | if (unlikely(esector < BM_SECT_PER_BIT-1)) | |
894 | goto out; | |
895 | if (unlikely(esector == (nr_sectors-1))) | |
896 | ebnr = lbnr; | |
897 | else | |
898 | ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1)); | |
899 | sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1); | |
900 | } else { | |
901 | /* We set it out of sync, or record resync failure. | |
902 | * Should not round anything here. */ | |
903 | sbnr = BM_SECT_TO_BIT(sector); | |
904 | ebnr = BM_SECT_TO_BIT(esector); | |
905 | } | |
b411b363 | 906 | |
5ab7d2c0 | 907 | count = update_sync_bits(device, sbnr, ebnr, mode); |
b411b363 | 908 | out: |
b30ab791 | 909 | put_ldev(device); |
73a01a18 | 910 | return count; |
b411b363 PR |
911 | } |
912 | ||
913 | static | |
b30ab791 | 914 | struct bm_extent *_bme_get(struct drbd_device *device, unsigned int enr) |
b411b363 PR |
915 | { |
916 | struct lc_element *e; | |
917 | struct bm_extent *bm_ext; | |
918 | int wakeup = 0; | |
919 | unsigned long rs_flags; | |
920 | ||
b30ab791 AG |
921 | spin_lock_irq(&device->al_lock); |
922 | if (device->resync_locked > device->resync->nr_elements/2) { | |
923 | spin_unlock_irq(&device->al_lock); | |
b411b363 PR |
924 | return NULL; |
925 | } | |
b30ab791 | 926 | e = lc_get(device->resync, enr); |
b411b363 PR |
927 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
928 | if (bm_ext) { | |
929 | if (bm_ext->lce.lc_number != enr) { | |
b30ab791 | 930 | bm_ext->rs_left = drbd_bm_e_weight(device, enr); |
b411b363 | 931 | bm_ext->rs_failed = 0; |
b30ab791 | 932 | lc_committed(device->resync); |
b411b363 PR |
933 | wakeup = 1; |
934 | } | |
935 | if (bm_ext->lce.refcnt == 1) | |
b30ab791 | 936 | device->resync_locked++; |
b411b363 PR |
937 | set_bit(BME_NO_WRITES, &bm_ext->flags); |
938 | } | |
b30ab791 AG |
939 | rs_flags = device->resync->flags; |
940 | spin_unlock_irq(&device->al_lock); | |
b411b363 | 941 | if (wakeup) |
b30ab791 | 942 | wake_up(&device->al_wait); |
b411b363 PR |
943 | |
944 | if (!bm_ext) { | |
945 | if (rs_flags & LC_STARVING) | |
d0180171 | 946 | drbd_warn(device, "Have to wait for element" |
b411b363 | 947 | " (resync LRU too small?)\n"); |
46a15bc3 | 948 | BUG_ON(rs_flags & LC_LOCKED); |
b411b363 PR |
949 | } |
950 | ||
951 | return bm_ext; | |
952 | } | |
953 | ||
b30ab791 | 954 | static int _is_in_al(struct drbd_device *device, unsigned int enr) |
b411b363 | 955 | { |
46a15bc3 | 956 | int rv; |
b411b363 | 957 | |
b30ab791 AG |
958 | spin_lock_irq(&device->al_lock); |
959 | rv = lc_is_used(device->act_log, enr); | |
960 | spin_unlock_irq(&device->al_lock); | |
b411b363 | 961 | |
b411b363 PR |
962 | return rv; |
963 | } | |
964 | ||
965 | /** | |
966 | * drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED | |
b30ab791 | 967 | * @device: DRBD device. |
b411b363 PR |
968 | * @sector: The sector number. |
969 | * | |
80a40e43 | 970 | * This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted. |
b411b363 | 971 | */ |
b30ab791 | 972 | int drbd_rs_begin_io(struct drbd_device *device, sector_t sector) |
b411b363 PR |
973 | { |
974 | unsigned int enr = BM_SECT_TO_EXT(sector); | |
975 | struct bm_extent *bm_ext; | |
976 | int i, sig; | |
e8299874 | 977 | bool sa; |
b411b363 | 978 | |
f91ab628 | 979 | retry: |
b30ab791 AG |
980 | sig = wait_event_interruptible(device->al_wait, |
981 | (bm_ext = _bme_get(device, enr))); | |
b411b363 | 982 | if (sig) |
80a40e43 | 983 | return -EINTR; |
b411b363 PR |
984 | |
985 | if (test_bit(BME_LOCKED, &bm_ext->flags)) | |
80a40e43 | 986 | return 0; |
b411b363 | 987 | |
e8299874 LE |
988 | /* step aside only while we are above c-min-rate; unless disabled. */ |
989 | sa = drbd_rs_c_min_rate_throttle(device); | |
990 | ||
b411b363 | 991 | for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { |
b30ab791 AG |
992 | sig = wait_event_interruptible(device->al_wait, |
993 | !_is_in_al(device, enr * AL_EXT_PER_BM_SECT + i) || | |
e8299874 | 994 | (sa && test_bit(BME_PRIORITY, &bm_ext->flags))); |
f91ab628 | 995 | |
e8299874 | 996 | if (sig || (sa && test_bit(BME_PRIORITY, &bm_ext->flags))) { |
b30ab791 AG |
997 | spin_lock_irq(&device->al_lock); |
998 | if (lc_put(device->resync, &bm_ext->lce) == 0) { | |
f91ab628 | 999 | bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */ |
b30ab791 AG |
1000 | device->resync_locked--; |
1001 | wake_up(&device->al_wait); | |
b411b363 | 1002 | } |
b30ab791 | 1003 | spin_unlock_irq(&device->al_lock); |
f91ab628 PR |
1004 | if (sig) |
1005 | return -EINTR; | |
1006 | if (schedule_timeout_interruptible(HZ/10)) | |
1007 | return -EINTR; | |
f91ab628 | 1008 | goto retry; |
b411b363 PR |
1009 | } |
1010 | } | |
b411b363 | 1011 | set_bit(BME_LOCKED, &bm_ext->flags); |
80a40e43 | 1012 | return 0; |
b411b363 PR |
1013 | } |
1014 | ||
1015 | /** | |
1016 | * drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep | |
b30ab791 | 1017 | * @device: DRBD device. |
b411b363 PR |
1018 | * @sector: The sector number. |
1019 | * | |
1020 | * Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then | |
1021 | * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN | |
1022 | * if there is still application IO going on in this area. | |
1023 | */ | |
b30ab791 | 1024 | int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector) |
b411b363 PR |
1025 | { |
1026 | unsigned int enr = BM_SECT_TO_EXT(sector); | |
1027 | const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT; | |
1028 | struct lc_element *e; | |
1029 | struct bm_extent *bm_ext; | |
1030 | int i; | |
ad3fee79 LE |
1031 | bool throttle = drbd_rs_should_slow_down(device, sector, true); |
1032 | ||
1033 | /* If we need to throttle, a half-locked (only marked BME_NO_WRITES, | |
1034 | * not yet BME_LOCKED) extent needs to be kicked out explicitly if we | |
1035 | * need to throttle. There is at most one such half-locked extent, | |
1036 | * which is remembered in resync_wenr. */ | |
1037 | ||
1038 | if (throttle && device->resync_wenr != enr) | |
1039 | return -EAGAIN; | |
b411b363 | 1040 | |
b30ab791 AG |
1041 | spin_lock_irq(&device->al_lock); |
1042 | if (device->resync_wenr != LC_FREE && device->resync_wenr != enr) { | |
b411b363 PR |
1043 | /* in case you have very heavy scattered io, it may |
1044 | * stall the syncer undefined if we give up the ref count | |
1045 | * when we try again and requeue. | |
1046 | * | |
1047 | * if we don't give up the refcount, but the next time | |
1048 | * we are scheduled this extent has been "synced" by new | |
1049 | * application writes, we'd miss the lc_put on the | |
1050 | * extent we keep the refcount on. | |
1051 | * so we remembered which extent we had to try again, and | |
1052 | * if the next requested one is something else, we do | |
1053 | * the lc_put here... | |
1054 | * we also have to wake_up | |
1055 | */ | |
b30ab791 | 1056 | e = lc_find(device->resync, device->resync_wenr); |
b411b363 PR |
1057 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1058 | if (bm_ext) { | |
0b0ba1ef AG |
1059 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1060 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); | |
b411b363 | 1061 | clear_bit(BME_NO_WRITES, &bm_ext->flags); |
b30ab791 | 1062 | device->resync_wenr = LC_FREE; |
ad3fee79 LE |
1063 | if (lc_put(device->resync, &bm_ext->lce) == 0) { |
1064 | bm_ext->flags = 0; | |
b30ab791 | 1065 | device->resync_locked--; |
ad3fee79 | 1066 | } |
b30ab791 | 1067 | wake_up(&device->al_wait); |
b411b363 | 1068 | } else { |
d0180171 | 1069 | drbd_alert(device, "LOGIC BUG\n"); |
b411b363 PR |
1070 | } |
1071 | } | |
1072 | /* TRY. */ | |
b30ab791 | 1073 | e = lc_try_get(device->resync, enr); |
b411b363 PR |
1074 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1075 | if (bm_ext) { | |
1076 | if (test_bit(BME_LOCKED, &bm_ext->flags)) | |
1077 | goto proceed; | |
1078 | if (!test_and_set_bit(BME_NO_WRITES, &bm_ext->flags)) { | |
b30ab791 | 1079 | device->resync_locked++; |
b411b363 PR |
1080 | } else { |
1081 | /* we did set the BME_NO_WRITES, | |
1082 | * but then could not set BME_LOCKED, | |
1083 | * so we tried again. | |
1084 | * drop the extra reference. */ | |
b411b363 | 1085 | bm_ext->lce.refcnt--; |
0b0ba1ef | 1086 | D_ASSERT(device, bm_ext->lce.refcnt > 0); |
b411b363 PR |
1087 | } |
1088 | goto check_al; | |
1089 | } else { | |
1090 | /* do we rather want to try later? */ | |
b30ab791 | 1091 | if (device->resync_locked > device->resync->nr_elements-3) |
b411b363 | 1092 | goto try_again; |
b411b363 | 1093 | /* Do or do not. There is no try. -- Yoda */ |
b30ab791 | 1094 | e = lc_get(device->resync, enr); |
b411b363 PR |
1095 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1096 | if (!bm_ext) { | |
b30ab791 | 1097 | const unsigned long rs_flags = device->resync->flags; |
b411b363 | 1098 | if (rs_flags & LC_STARVING) |
d0180171 | 1099 | drbd_warn(device, "Have to wait for element" |
b411b363 | 1100 | " (resync LRU too small?)\n"); |
46a15bc3 | 1101 | BUG_ON(rs_flags & LC_LOCKED); |
b411b363 PR |
1102 | goto try_again; |
1103 | } | |
1104 | if (bm_ext->lce.lc_number != enr) { | |
b30ab791 | 1105 | bm_ext->rs_left = drbd_bm_e_weight(device, enr); |
b411b363 | 1106 | bm_ext->rs_failed = 0; |
b30ab791 AG |
1107 | lc_committed(device->resync); |
1108 | wake_up(&device->al_wait); | |
0b0ba1ef | 1109 | D_ASSERT(device, test_bit(BME_LOCKED, &bm_ext->flags) == 0); |
b411b363 PR |
1110 | } |
1111 | set_bit(BME_NO_WRITES, &bm_ext->flags); | |
0b0ba1ef | 1112 | D_ASSERT(device, bm_ext->lce.refcnt == 1); |
b30ab791 | 1113 | device->resync_locked++; |
b411b363 PR |
1114 | goto check_al; |
1115 | } | |
1116 | check_al: | |
b411b363 | 1117 | for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { |
b30ab791 | 1118 | if (lc_is_used(device->act_log, al_enr+i)) |
b411b363 PR |
1119 | goto try_again; |
1120 | } | |
1121 | set_bit(BME_LOCKED, &bm_ext->flags); | |
1122 | proceed: | |
b30ab791 AG |
1123 | device->resync_wenr = LC_FREE; |
1124 | spin_unlock_irq(&device->al_lock); | |
b411b363 PR |
1125 | return 0; |
1126 | ||
1127 | try_again: | |
ad3fee79 LE |
1128 | if (bm_ext) { |
1129 | if (throttle) { | |
1130 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); | |
1131 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); | |
1132 | clear_bit(BME_NO_WRITES, &bm_ext->flags); | |
1133 | device->resync_wenr = LC_FREE; | |
1134 | if (lc_put(device->resync, &bm_ext->lce) == 0) { | |
1135 | bm_ext->flags = 0; | |
1136 | device->resync_locked--; | |
1137 | } | |
1138 | wake_up(&device->al_wait); | |
1139 | } else | |
1140 | device->resync_wenr = enr; | |
1141 | } | |
b30ab791 | 1142 | spin_unlock_irq(&device->al_lock); |
b411b363 PR |
1143 | return -EAGAIN; |
1144 | } | |
1145 | ||
b30ab791 | 1146 | void drbd_rs_complete_io(struct drbd_device *device, sector_t sector) |
b411b363 PR |
1147 | { |
1148 | unsigned int enr = BM_SECT_TO_EXT(sector); | |
1149 | struct lc_element *e; | |
1150 | struct bm_extent *bm_ext; | |
1151 | unsigned long flags; | |
1152 | ||
b30ab791 AG |
1153 | spin_lock_irqsave(&device->al_lock, flags); |
1154 | e = lc_find(device->resync, enr); | |
b411b363 PR |
1155 | bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; |
1156 | if (!bm_ext) { | |
b30ab791 | 1157 | spin_unlock_irqrestore(&device->al_lock, flags); |
b411b363 | 1158 | if (__ratelimit(&drbd_ratelimit_state)) |
d0180171 | 1159 | drbd_err(device, "drbd_rs_complete_io() called, but extent not found\n"); |
b411b363 PR |
1160 | return; |
1161 | } | |
1162 | ||
1163 | if (bm_ext->lce.refcnt == 0) { | |
b30ab791 | 1164 | spin_unlock_irqrestore(&device->al_lock, flags); |
d0180171 | 1165 | drbd_err(device, "drbd_rs_complete_io(,%llu [=%u]) called, " |
b411b363 PR |
1166 | "but refcnt is 0!?\n", |
1167 | (unsigned long long)sector, enr); | |
1168 | return; | |
1169 | } | |
1170 | ||
b30ab791 | 1171 | if (lc_put(device->resync, &bm_ext->lce) == 0) { |
e3555d85 | 1172 | bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */ |
b30ab791 AG |
1173 | device->resync_locked--; |
1174 | wake_up(&device->al_wait); | |
b411b363 PR |
1175 | } |
1176 | ||
b30ab791 | 1177 | spin_unlock_irqrestore(&device->al_lock, flags); |
b411b363 PR |
1178 | } |
1179 | ||
1180 | /** | |
1181 | * drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED) | |
b30ab791 | 1182 | * @device: DRBD device. |
b411b363 | 1183 | */ |
b30ab791 | 1184 | void drbd_rs_cancel_all(struct drbd_device *device) |
b411b363 | 1185 | { |
b30ab791 | 1186 | spin_lock_irq(&device->al_lock); |
b411b363 | 1187 | |
b30ab791 AG |
1188 | if (get_ldev_if_state(device, D_FAILED)) { /* Makes sure ->resync is there. */ |
1189 | lc_reset(device->resync); | |
1190 | put_ldev(device); | |
b411b363 | 1191 | } |
b30ab791 AG |
1192 | device->resync_locked = 0; |
1193 | device->resync_wenr = LC_FREE; | |
1194 | spin_unlock_irq(&device->al_lock); | |
1195 | wake_up(&device->al_wait); | |
b411b363 PR |
1196 | } |
1197 | ||
1198 | /** | |
1199 | * drbd_rs_del_all() - Gracefully remove all extents from the resync LRU | |
b30ab791 | 1200 | * @device: DRBD device. |
b411b363 PR |
1201 | * |
1202 | * Returns 0 upon success, -EAGAIN if at least one reference count was | |
1203 | * not zero. | |
1204 | */ | |
b30ab791 | 1205 | int drbd_rs_del_all(struct drbd_device *device) |
b411b363 PR |
1206 | { |
1207 | struct lc_element *e; | |
1208 | struct bm_extent *bm_ext; | |
1209 | int i; | |
1210 | ||
b30ab791 | 1211 | spin_lock_irq(&device->al_lock); |
b411b363 | 1212 | |
b30ab791 | 1213 | if (get_ldev_if_state(device, D_FAILED)) { |
b411b363 | 1214 | /* ok, ->resync is there. */ |
b30ab791 AG |
1215 | for (i = 0; i < device->resync->nr_elements; i++) { |
1216 | e = lc_element_by_index(device->resync, i); | |
b2b163dd | 1217 | bm_ext = lc_entry(e, struct bm_extent, lce); |
b411b363 PR |
1218 | if (bm_ext->lce.lc_number == LC_FREE) |
1219 | continue; | |
b30ab791 | 1220 | if (bm_ext->lce.lc_number == device->resync_wenr) { |
d0180171 | 1221 | drbd_info(device, "dropping %u in drbd_rs_del_all, apparently" |
b411b363 | 1222 | " got 'synced' by application io\n", |
b30ab791 | 1223 | device->resync_wenr); |
0b0ba1ef AG |
1224 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1225 | D_ASSERT(device, test_bit(BME_NO_WRITES, &bm_ext->flags)); | |
b411b363 | 1226 | clear_bit(BME_NO_WRITES, &bm_ext->flags); |
b30ab791 AG |
1227 | device->resync_wenr = LC_FREE; |
1228 | lc_put(device->resync, &bm_ext->lce); | |
b411b363 PR |
1229 | } |
1230 | if (bm_ext->lce.refcnt != 0) { | |
d0180171 | 1231 | drbd_info(device, "Retrying drbd_rs_del_all() later. " |
b411b363 | 1232 | "refcnt=%d\n", bm_ext->lce.refcnt); |
b30ab791 AG |
1233 | put_ldev(device); |
1234 | spin_unlock_irq(&device->al_lock); | |
b411b363 PR |
1235 | return -EAGAIN; |
1236 | } | |
0b0ba1ef AG |
1237 | D_ASSERT(device, !test_bit(BME_LOCKED, &bm_ext->flags)); |
1238 | D_ASSERT(device, !test_bit(BME_NO_WRITES, &bm_ext->flags)); | |
b30ab791 | 1239 | lc_del(device->resync, &bm_ext->lce); |
b411b363 | 1240 | } |
0b0ba1ef | 1241 | D_ASSERT(device, device->resync->used == 0); |
b30ab791 | 1242 | put_ldev(device); |
b411b363 | 1243 | } |
b30ab791 AG |
1244 | spin_unlock_irq(&device->al_lock); |
1245 | wake_up(&device->al_wait); | |
b411b363 PR |
1246 | |
1247 | return 0; | |
1248 | } |