Commit | Line | Data |
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b411b363 PR |
1 | /* |
2 | drbd_bitmap.c | |
3 | ||
4 | This file is part of DRBD by Philipp Reisner and Lars Ellenberg. | |
5 | ||
6 | Copyright (C) 2004-2008, LINBIT Information Technologies GmbH. | |
7 | Copyright (C) 2004-2008, Philipp Reisner <philipp.reisner@linbit.com>. | |
8 | Copyright (C) 2004-2008, 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 | #include <linux/bitops.h> | |
26 | #include <linux/vmalloc.h> | |
27 | #include <linux/string.h> | |
28 | #include <linux/drbd.h> | |
29 | #include <asm/kmap_types.h> | |
30 | #include "drbd_int.h" | |
31 | ||
32 | /* OPAQUE outside this file! | |
33 | * interface defined in drbd_int.h | |
34 | ||
35 | * convention: | |
36 | * function name drbd_bm_... => used elsewhere, "public". | |
37 | * function name bm_... => internal to implementation, "private". | |
38 | ||
39 | * Note that since find_first_bit returns int, at the current granularity of | |
40 | * the bitmap (4KB per byte), this implementation "only" supports up to | |
41 | * 1<<(32+12) == 16 TB... | |
42 | */ | |
43 | ||
44 | /* | |
45 | * NOTE | |
46 | * Access to the *bm_pages is protected by bm_lock. | |
47 | * It is safe to read the other members within the lock. | |
48 | * | |
49 | * drbd_bm_set_bits is called from bio_endio callbacks, | |
50 | * We may be called with irq already disabled, | |
51 | * so we need spin_lock_irqsave(). | |
52 | * And we need the kmap_atomic. | |
53 | */ | |
54 | struct drbd_bitmap { | |
55 | struct page **bm_pages; | |
56 | spinlock_t bm_lock; | |
57 | /* WARNING unsigned long bm_*: | |
58 | * 32bit number of bit offset is just enough for 512 MB bitmap. | |
59 | * it will blow up if we make the bitmap bigger... | |
60 | * not that it makes much sense to have a bitmap that large, | |
61 | * rather change the granularity to 16k or 64k or something. | |
62 | * (that implies other problems, however...) | |
63 | */ | |
64 | unsigned long bm_set; /* nr of set bits; THINK maybe atomic_t? */ | |
65 | unsigned long bm_bits; | |
66 | size_t bm_words; | |
67 | size_t bm_number_of_pages; | |
68 | sector_t bm_dev_capacity; | |
69 | struct semaphore bm_change; /* serializes resize operations */ | |
70 | ||
71 | atomic_t bm_async_io; | |
72 | wait_queue_head_t bm_io_wait; | |
73 | ||
74 | unsigned long bm_flags; | |
75 | ||
76 | /* debugging aid, in case we are still racy somewhere */ | |
77 | char *bm_why; | |
78 | struct task_struct *bm_task; | |
79 | }; | |
80 | ||
81 | /* definition of bits in bm_flags */ | |
82 | #define BM_LOCKED 0 | |
83 | #define BM_MD_IO_ERROR 1 | |
84 | #define BM_P_VMALLOCED 2 | |
85 | ||
86 | static int bm_is_locked(struct drbd_bitmap *b) | |
87 | { | |
88 | return test_bit(BM_LOCKED, &b->bm_flags); | |
89 | } | |
90 | ||
91 | #define bm_print_lock_info(m) __bm_print_lock_info(m, __func__) | |
92 | static void __bm_print_lock_info(struct drbd_conf *mdev, const char *func) | |
93 | { | |
94 | struct drbd_bitmap *b = mdev->bitmap; | |
95 | if (!__ratelimit(&drbd_ratelimit_state)) | |
96 | return; | |
97 | dev_err(DEV, "FIXME %s in %s, bitmap locked for '%s' by %s\n", | |
98 | current == mdev->receiver.task ? "receiver" : | |
99 | current == mdev->asender.task ? "asender" : | |
100 | current == mdev->worker.task ? "worker" : current->comm, | |
101 | func, b->bm_why ?: "?", | |
102 | b->bm_task == mdev->receiver.task ? "receiver" : | |
103 | b->bm_task == mdev->asender.task ? "asender" : | |
104 | b->bm_task == mdev->worker.task ? "worker" : "?"); | |
105 | } | |
106 | ||
107 | void drbd_bm_lock(struct drbd_conf *mdev, char *why) | |
108 | { | |
109 | struct drbd_bitmap *b = mdev->bitmap; | |
110 | int trylock_failed; | |
111 | ||
112 | if (!b) { | |
113 | dev_err(DEV, "FIXME no bitmap in drbd_bm_lock!?\n"); | |
114 | return; | |
115 | } | |
116 | ||
117 | trylock_failed = down_trylock(&b->bm_change); | |
118 | ||
119 | if (trylock_failed) { | |
120 | dev_warn(DEV, "%s going to '%s' but bitmap already locked for '%s' by %s\n", | |
121 | current == mdev->receiver.task ? "receiver" : | |
122 | current == mdev->asender.task ? "asender" : | |
123 | current == mdev->worker.task ? "worker" : current->comm, | |
124 | why, b->bm_why ?: "?", | |
125 | b->bm_task == mdev->receiver.task ? "receiver" : | |
126 | b->bm_task == mdev->asender.task ? "asender" : | |
127 | b->bm_task == mdev->worker.task ? "worker" : "?"); | |
128 | down(&b->bm_change); | |
129 | } | |
130 | if (__test_and_set_bit(BM_LOCKED, &b->bm_flags)) | |
131 | dev_err(DEV, "FIXME bitmap already locked in bm_lock\n"); | |
132 | ||
133 | b->bm_why = why; | |
134 | b->bm_task = current; | |
135 | } | |
136 | ||
137 | void drbd_bm_unlock(struct drbd_conf *mdev) | |
138 | { | |
139 | struct drbd_bitmap *b = mdev->bitmap; | |
140 | if (!b) { | |
141 | dev_err(DEV, "FIXME no bitmap in drbd_bm_unlock!?\n"); | |
142 | return; | |
143 | } | |
144 | ||
145 | if (!__test_and_clear_bit(BM_LOCKED, &mdev->bitmap->bm_flags)) | |
146 | dev_err(DEV, "FIXME bitmap not locked in bm_unlock\n"); | |
147 | ||
148 | b->bm_why = NULL; | |
149 | b->bm_task = NULL; | |
150 | up(&b->bm_change); | |
151 | } | |
152 | ||
153 | /* word offset to long pointer */ | |
154 | static unsigned long *__bm_map_paddr(struct drbd_bitmap *b, unsigned long offset, const enum km_type km) | |
155 | { | |
156 | struct page *page; | |
157 | unsigned long page_nr; | |
158 | ||
159 | /* page_nr = (word*sizeof(long)) >> PAGE_SHIFT; */ | |
160 | page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3); | |
161 | BUG_ON(page_nr >= b->bm_number_of_pages); | |
162 | page = b->bm_pages[page_nr]; | |
163 | ||
164 | return (unsigned long *) kmap_atomic(page, km); | |
165 | } | |
166 | ||
167 | static unsigned long * bm_map_paddr(struct drbd_bitmap *b, unsigned long offset) | |
168 | { | |
169 | return __bm_map_paddr(b, offset, KM_IRQ1); | |
170 | } | |
171 | ||
172 | static void __bm_unmap(unsigned long *p_addr, const enum km_type km) | |
173 | { | |
174 | kunmap_atomic(p_addr, km); | |
175 | }; | |
176 | ||
177 | static void bm_unmap(unsigned long *p_addr) | |
178 | { | |
179 | return __bm_unmap(p_addr, KM_IRQ1); | |
180 | } | |
181 | ||
182 | /* long word offset of _bitmap_ sector */ | |
183 | #define S2W(s) ((s)<<(BM_EXT_SHIFT-BM_BLOCK_SHIFT-LN2_BPL)) | |
184 | /* word offset from start of bitmap to word number _in_page_ | |
185 | * modulo longs per page | |
186 | #define MLPP(X) ((X) % (PAGE_SIZE/sizeof(long)) | |
187 | hm, well, Philipp thinks gcc might not optimze the % into & (... - 1) | |
188 | so do it explicitly: | |
189 | */ | |
190 | #define MLPP(X) ((X) & ((PAGE_SIZE/sizeof(long))-1)) | |
191 | ||
192 | /* Long words per page */ | |
193 | #define LWPP (PAGE_SIZE/sizeof(long)) | |
194 | ||
195 | /* | |
196 | * actually most functions herein should take a struct drbd_bitmap*, not a | |
197 | * struct drbd_conf*, but for the debug macros I like to have the mdev around | |
198 | * to be able to report device specific. | |
199 | */ | |
200 | ||
201 | static void bm_free_pages(struct page **pages, unsigned long number) | |
202 | { | |
203 | unsigned long i; | |
204 | if (!pages) | |
205 | return; | |
206 | ||
207 | for (i = 0; i < number; i++) { | |
208 | if (!pages[i]) { | |
209 | printk(KERN_ALERT "drbd: bm_free_pages tried to free " | |
210 | "a NULL pointer; i=%lu n=%lu\n", | |
211 | i, number); | |
212 | continue; | |
213 | } | |
214 | __free_page(pages[i]); | |
215 | pages[i] = NULL; | |
216 | } | |
217 | } | |
218 | ||
219 | static void bm_vk_free(void *ptr, int v) | |
220 | { | |
221 | if (v) | |
222 | vfree(ptr); | |
223 | else | |
224 | kfree(ptr); | |
225 | } | |
226 | ||
227 | /* | |
228 | * "have" and "want" are NUMBER OF PAGES. | |
229 | */ | |
230 | static struct page **bm_realloc_pages(struct drbd_bitmap *b, unsigned long want) | |
231 | { | |
232 | struct page **old_pages = b->bm_pages; | |
233 | struct page **new_pages, *page; | |
234 | unsigned int i, bytes, vmalloced = 0; | |
235 | unsigned long have = b->bm_number_of_pages; | |
236 | ||
237 | BUG_ON(have == 0 && old_pages != NULL); | |
238 | BUG_ON(have != 0 && old_pages == NULL); | |
239 | ||
240 | if (have == want) | |
241 | return old_pages; | |
242 | ||
243 | /* Trying kmalloc first, falling back to vmalloc. | |
244 | * GFP_KERNEL is ok, as this is done when a lower level disk is | |
245 | * "attached" to the drbd. Context is receiver thread or cqueue | |
246 | * thread. As we have no disk yet, we are not in the IO path, | |
247 | * not even the IO path of the peer. */ | |
248 | bytes = sizeof(struct page *)*want; | |
249 | new_pages = kmalloc(bytes, GFP_KERNEL); | |
250 | if (!new_pages) { | |
251 | new_pages = vmalloc(bytes); | |
252 | if (!new_pages) | |
253 | return NULL; | |
254 | vmalloced = 1; | |
255 | } | |
256 | ||
257 | memset(new_pages, 0, bytes); | |
258 | if (want >= have) { | |
259 | for (i = 0; i < have; i++) | |
260 | new_pages[i] = old_pages[i]; | |
261 | for (; i < want; i++) { | |
262 | page = alloc_page(GFP_HIGHUSER); | |
263 | if (!page) { | |
264 | bm_free_pages(new_pages + have, i - have); | |
265 | bm_vk_free(new_pages, vmalloced); | |
266 | return NULL; | |
267 | } | |
268 | new_pages[i] = page; | |
269 | } | |
270 | } else { | |
271 | for (i = 0; i < want; i++) | |
272 | new_pages[i] = old_pages[i]; | |
273 | /* NOT HERE, we are outside the spinlock! | |
274 | bm_free_pages(old_pages + want, have - want); | |
275 | */ | |
276 | } | |
277 | ||
278 | if (vmalloced) | |
279 | set_bit(BM_P_VMALLOCED, &b->bm_flags); | |
280 | else | |
281 | clear_bit(BM_P_VMALLOCED, &b->bm_flags); | |
282 | ||
283 | return new_pages; | |
284 | } | |
285 | ||
286 | /* | |
287 | * called on driver init only. TODO call when a device is created. | |
288 | * allocates the drbd_bitmap, and stores it in mdev->bitmap. | |
289 | */ | |
290 | int drbd_bm_init(struct drbd_conf *mdev) | |
291 | { | |
292 | struct drbd_bitmap *b = mdev->bitmap; | |
293 | WARN_ON(b != NULL); | |
294 | b = kzalloc(sizeof(struct drbd_bitmap), GFP_KERNEL); | |
295 | if (!b) | |
296 | return -ENOMEM; | |
297 | spin_lock_init(&b->bm_lock); | |
298 | init_MUTEX(&b->bm_change); | |
299 | init_waitqueue_head(&b->bm_io_wait); | |
300 | ||
301 | mdev->bitmap = b; | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
306 | sector_t drbd_bm_capacity(struct drbd_conf *mdev) | |
307 | { | |
308 | ERR_IF(!mdev->bitmap) return 0; | |
309 | return mdev->bitmap->bm_dev_capacity; | |
310 | } | |
311 | ||
312 | /* called on driver unload. TODO: call when a device is destroyed. | |
313 | */ | |
314 | void drbd_bm_cleanup(struct drbd_conf *mdev) | |
315 | { | |
316 | ERR_IF (!mdev->bitmap) return; | |
317 | bm_free_pages(mdev->bitmap->bm_pages, mdev->bitmap->bm_number_of_pages); | |
318 | bm_vk_free(mdev->bitmap->bm_pages, test_bit(BM_P_VMALLOCED, &mdev->bitmap->bm_flags)); | |
319 | kfree(mdev->bitmap); | |
320 | mdev->bitmap = NULL; | |
321 | } | |
322 | ||
323 | /* | |
324 | * since (b->bm_bits % BITS_PER_LONG) != 0, | |
325 | * this masks out the remaining bits. | |
326 | * Returns the number of bits cleared. | |
327 | */ | |
328 | static int bm_clear_surplus(struct drbd_bitmap *b) | |
329 | { | |
330 | const unsigned long mask = (1UL << (b->bm_bits & (BITS_PER_LONG-1))) - 1; | |
331 | size_t w = b->bm_bits >> LN2_BPL; | |
332 | int cleared = 0; | |
333 | unsigned long *p_addr, *bm; | |
334 | ||
335 | p_addr = bm_map_paddr(b, w); | |
336 | bm = p_addr + MLPP(w); | |
337 | if (w < b->bm_words) { | |
338 | cleared = hweight_long(*bm & ~mask); | |
339 | *bm &= mask; | |
340 | w++; bm++; | |
341 | } | |
342 | ||
343 | if (w < b->bm_words) { | |
344 | cleared += hweight_long(*bm); | |
345 | *bm = 0; | |
346 | } | |
347 | bm_unmap(p_addr); | |
348 | return cleared; | |
349 | } | |
350 | ||
351 | static void bm_set_surplus(struct drbd_bitmap *b) | |
352 | { | |
353 | const unsigned long mask = (1UL << (b->bm_bits & (BITS_PER_LONG-1))) - 1; | |
354 | size_t w = b->bm_bits >> LN2_BPL; | |
355 | unsigned long *p_addr, *bm; | |
356 | ||
357 | p_addr = bm_map_paddr(b, w); | |
358 | bm = p_addr + MLPP(w); | |
359 | if (w < b->bm_words) { | |
360 | *bm |= ~mask; | |
361 | bm++; w++; | |
362 | } | |
363 | ||
364 | if (w < b->bm_words) { | |
365 | *bm = ~(0UL); | |
366 | } | |
367 | bm_unmap(p_addr); | |
368 | } | |
369 | ||
370 | static unsigned long __bm_count_bits(struct drbd_bitmap *b, const int swap_endian) | |
371 | { | |
372 | unsigned long *p_addr, *bm, offset = 0; | |
373 | unsigned long bits = 0; | |
374 | unsigned long i, do_now; | |
375 | ||
376 | while (offset < b->bm_words) { | |
377 | i = do_now = min_t(size_t, b->bm_words-offset, LWPP); | |
378 | p_addr = __bm_map_paddr(b, offset, KM_USER0); | |
379 | bm = p_addr + MLPP(offset); | |
380 | while (i--) { | |
381 | #ifndef __LITTLE_ENDIAN | |
382 | if (swap_endian) | |
383 | *bm = lel_to_cpu(*bm); | |
384 | #endif | |
385 | bits += hweight_long(*bm++); | |
386 | } | |
387 | __bm_unmap(p_addr, KM_USER0); | |
388 | offset += do_now; | |
389 | cond_resched(); | |
390 | } | |
391 | ||
392 | return bits; | |
393 | } | |
394 | ||
395 | static unsigned long bm_count_bits(struct drbd_bitmap *b) | |
396 | { | |
397 | return __bm_count_bits(b, 0); | |
398 | } | |
399 | ||
400 | static unsigned long bm_count_bits_swap_endian(struct drbd_bitmap *b) | |
401 | { | |
402 | return __bm_count_bits(b, 1); | |
403 | } | |
404 | ||
405 | /* offset and len in long words.*/ | |
406 | static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len) | |
407 | { | |
408 | unsigned long *p_addr, *bm; | |
409 | size_t do_now, end; | |
410 | ||
411 | #define BM_SECTORS_PER_BIT (BM_BLOCK_SIZE/512) | |
412 | ||
413 | end = offset + len; | |
414 | ||
415 | if (end > b->bm_words) { | |
416 | printk(KERN_ALERT "drbd: bm_memset end > bm_words\n"); | |
417 | return; | |
418 | } | |
419 | ||
420 | while (offset < end) { | |
421 | do_now = min_t(size_t, ALIGN(offset + 1, LWPP), end) - offset; | |
422 | p_addr = bm_map_paddr(b, offset); | |
423 | bm = p_addr + MLPP(offset); | |
424 | if (bm+do_now > p_addr + LWPP) { | |
425 | printk(KERN_ALERT "drbd: BUG BUG BUG! p_addr:%p bm:%p do_now:%d\n", | |
426 | p_addr, bm, (int)do_now); | |
427 | break; /* breaks to after catch_oob_access_end() only! */ | |
428 | } | |
429 | memset(bm, c, do_now * sizeof(long)); | |
430 | bm_unmap(p_addr); | |
431 | offset += do_now; | |
432 | } | |
433 | } | |
434 | ||
435 | /* | |
436 | * make sure the bitmap has enough room for the attached storage, | |
437 | * if necessary, resize. | |
438 | * called whenever we may have changed the device size. | |
439 | * returns -ENOMEM if we could not allocate enough memory, 0 on success. | |
440 | * In case this is actually a resize, we copy the old bitmap into the new one. | |
441 | * Otherwise, the bitmap is initialized to all bits set. | |
442 | */ | |
443 | int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity) | |
444 | { | |
445 | struct drbd_bitmap *b = mdev->bitmap; | |
446 | unsigned long bits, words, owords, obits, *p_addr, *bm; | |
447 | unsigned long want, have, onpages; /* number of pages */ | |
448 | struct page **npages, **opages = NULL; | |
449 | int err = 0, growing; | |
450 | int opages_vmalloced; | |
451 | ||
452 | ERR_IF(!b) return -ENOMEM; | |
453 | ||
454 | drbd_bm_lock(mdev, "resize"); | |
455 | ||
456 | dev_info(DEV, "drbd_bm_resize called with capacity == %llu\n", | |
457 | (unsigned long long)capacity); | |
458 | ||
459 | if (capacity == b->bm_dev_capacity) | |
460 | goto out; | |
461 | ||
462 | opages_vmalloced = test_bit(BM_P_VMALLOCED, &b->bm_flags); | |
463 | ||
464 | if (capacity == 0) { | |
465 | spin_lock_irq(&b->bm_lock); | |
466 | opages = b->bm_pages; | |
467 | onpages = b->bm_number_of_pages; | |
468 | owords = b->bm_words; | |
469 | b->bm_pages = NULL; | |
470 | b->bm_number_of_pages = | |
471 | b->bm_set = | |
472 | b->bm_bits = | |
473 | b->bm_words = | |
474 | b->bm_dev_capacity = 0; | |
475 | spin_unlock_irq(&b->bm_lock); | |
476 | bm_free_pages(opages, onpages); | |
477 | bm_vk_free(opages, opages_vmalloced); | |
478 | goto out; | |
479 | } | |
480 | bits = BM_SECT_TO_BIT(ALIGN(capacity, BM_SECT_PER_BIT)); | |
481 | ||
482 | /* if we would use | |
483 | words = ALIGN(bits,BITS_PER_LONG) >> LN2_BPL; | |
484 | a 32bit host could present the wrong number of words | |
485 | to a 64bit host. | |
486 | */ | |
487 | words = ALIGN(bits, 64) >> LN2_BPL; | |
488 | ||
489 | if (get_ldev(mdev)) { | |
490 | D_ASSERT((u64)bits <= (((u64)mdev->ldev->md.md_size_sect-MD_BM_OFFSET) << 12)); | |
491 | put_ldev(mdev); | |
492 | } | |
493 | ||
494 | /* one extra long to catch off by one errors */ | |
495 | want = ALIGN((words+1)*sizeof(long), PAGE_SIZE) >> PAGE_SHIFT; | |
496 | have = b->bm_number_of_pages; | |
497 | if (want == have) { | |
498 | D_ASSERT(b->bm_pages != NULL); | |
499 | npages = b->bm_pages; | |
500 | } else { | |
501 | if (FAULT_ACTIVE(mdev, DRBD_FAULT_BM_ALLOC)) | |
502 | npages = NULL; | |
503 | else | |
504 | npages = bm_realloc_pages(b, want); | |
505 | } | |
506 | ||
507 | if (!npages) { | |
508 | err = -ENOMEM; | |
509 | goto out; | |
510 | } | |
511 | ||
512 | spin_lock_irq(&b->bm_lock); | |
513 | opages = b->bm_pages; | |
514 | owords = b->bm_words; | |
515 | obits = b->bm_bits; | |
516 | ||
517 | growing = bits > obits; | |
518 | if (opages) | |
519 | bm_set_surplus(b); | |
520 | ||
521 | b->bm_pages = npages; | |
522 | b->bm_number_of_pages = want; | |
523 | b->bm_bits = bits; | |
524 | b->bm_words = words; | |
525 | b->bm_dev_capacity = capacity; | |
526 | ||
527 | if (growing) { | |
528 | bm_memset(b, owords, 0xff, words-owords); | |
529 | b->bm_set += bits - obits; | |
530 | } | |
531 | ||
532 | if (want < have) { | |
533 | /* implicit: (opages != NULL) && (opages != npages) */ | |
534 | bm_free_pages(opages + want, have - want); | |
535 | } | |
536 | ||
537 | p_addr = bm_map_paddr(b, words); | |
538 | bm = p_addr + MLPP(words); | |
539 | *bm = DRBD_MAGIC; | |
540 | bm_unmap(p_addr); | |
541 | ||
542 | (void)bm_clear_surplus(b); | |
543 | ||
544 | spin_unlock_irq(&b->bm_lock); | |
545 | if (opages != npages) | |
546 | bm_vk_free(opages, opages_vmalloced); | |
547 | if (!growing) | |
548 | b->bm_set = bm_count_bits(b); | |
549 | dev_info(DEV, "resync bitmap: bits=%lu words=%lu\n", bits, words); | |
550 | ||
551 | out: | |
552 | drbd_bm_unlock(mdev); | |
553 | return err; | |
554 | } | |
555 | ||
556 | /* inherently racy: | |
557 | * if not protected by other means, return value may be out of date when | |
558 | * leaving this function... | |
559 | * we still need to lock it, since it is important that this returns | |
560 | * bm_set == 0 precisely. | |
561 | * | |
562 | * maybe bm_set should be atomic_t ? | |
563 | */ | |
564 | static unsigned long _drbd_bm_total_weight(struct drbd_conf *mdev) | |
565 | { | |
566 | struct drbd_bitmap *b = mdev->bitmap; | |
567 | unsigned long s; | |
568 | unsigned long flags; | |
569 | ||
570 | ERR_IF(!b) return 0; | |
571 | ERR_IF(!b->bm_pages) return 0; | |
572 | ||
573 | spin_lock_irqsave(&b->bm_lock, flags); | |
574 | s = b->bm_set; | |
575 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
576 | ||
577 | return s; | |
578 | } | |
579 | ||
580 | unsigned long drbd_bm_total_weight(struct drbd_conf *mdev) | |
581 | { | |
582 | unsigned long s; | |
583 | /* if I don't have a disk, I don't know about out-of-sync status */ | |
584 | if (!get_ldev_if_state(mdev, D_NEGOTIATING)) | |
585 | return 0; | |
586 | s = _drbd_bm_total_weight(mdev); | |
587 | put_ldev(mdev); | |
588 | return s; | |
589 | } | |
590 | ||
591 | size_t drbd_bm_words(struct drbd_conf *mdev) | |
592 | { | |
593 | struct drbd_bitmap *b = mdev->bitmap; | |
594 | ERR_IF(!b) return 0; | |
595 | ERR_IF(!b->bm_pages) return 0; | |
596 | ||
597 | return b->bm_words; | |
598 | } | |
599 | ||
600 | unsigned long drbd_bm_bits(struct drbd_conf *mdev) | |
601 | { | |
602 | struct drbd_bitmap *b = mdev->bitmap; | |
603 | ERR_IF(!b) return 0; | |
604 | ||
605 | return b->bm_bits; | |
606 | } | |
607 | ||
608 | /* merge number words from buffer into the bitmap starting at offset. | |
609 | * buffer[i] is expected to be little endian unsigned long. | |
610 | * bitmap must be locked by drbd_bm_lock. | |
611 | * currently only used from receive_bitmap. | |
612 | */ | |
613 | void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number, | |
614 | unsigned long *buffer) | |
615 | { | |
616 | struct drbd_bitmap *b = mdev->bitmap; | |
617 | unsigned long *p_addr, *bm; | |
618 | unsigned long word, bits; | |
619 | size_t end, do_now; | |
620 | ||
621 | end = offset + number; | |
622 | ||
623 | ERR_IF(!b) return; | |
624 | ERR_IF(!b->bm_pages) return; | |
625 | if (number == 0) | |
626 | return; | |
627 | WARN_ON(offset >= b->bm_words); | |
628 | WARN_ON(end > b->bm_words); | |
629 | ||
630 | spin_lock_irq(&b->bm_lock); | |
631 | while (offset < end) { | |
632 | do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset; | |
633 | p_addr = bm_map_paddr(b, offset); | |
634 | bm = p_addr + MLPP(offset); | |
635 | offset += do_now; | |
636 | while (do_now--) { | |
637 | bits = hweight_long(*bm); | |
638 | word = *bm | lel_to_cpu(*buffer++); | |
639 | *bm++ = word; | |
640 | b->bm_set += hweight_long(word) - bits; | |
641 | } | |
642 | bm_unmap(p_addr); | |
643 | } | |
644 | /* with 32bit <-> 64bit cross-platform connect | |
645 | * this is only correct for current usage, | |
646 | * where we _know_ that we are 64 bit aligned, | |
647 | * and know that this function is used in this way, too... | |
648 | */ | |
649 | if (end == b->bm_words) | |
650 | b->bm_set -= bm_clear_surplus(b); | |
651 | ||
652 | spin_unlock_irq(&b->bm_lock); | |
653 | } | |
654 | ||
655 | /* copy number words from the bitmap starting at offset into the buffer. | |
656 | * buffer[i] will be little endian unsigned long. | |
657 | */ | |
658 | void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset, size_t number, | |
659 | unsigned long *buffer) | |
660 | { | |
661 | struct drbd_bitmap *b = mdev->bitmap; | |
662 | unsigned long *p_addr, *bm; | |
663 | size_t end, do_now; | |
664 | ||
665 | end = offset + number; | |
666 | ||
667 | ERR_IF(!b) return; | |
668 | ERR_IF(!b->bm_pages) return; | |
669 | ||
670 | spin_lock_irq(&b->bm_lock); | |
671 | if ((offset >= b->bm_words) || | |
672 | (end > b->bm_words) || | |
673 | (number <= 0)) | |
674 | dev_err(DEV, "offset=%lu number=%lu bm_words=%lu\n", | |
675 | (unsigned long) offset, | |
676 | (unsigned long) number, | |
677 | (unsigned long) b->bm_words); | |
678 | else { | |
679 | while (offset < end) { | |
680 | do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset; | |
681 | p_addr = bm_map_paddr(b, offset); | |
682 | bm = p_addr + MLPP(offset); | |
683 | offset += do_now; | |
684 | while (do_now--) | |
685 | *buffer++ = cpu_to_lel(*bm++); | |
686 | bm_unmap(p_addr); | |
687 | } | |
688 | } | |
689 | spin_unlock_irq(&b->bm_lock); | |
690 | } | |
691 | ||
692 | /* set all bits in the bitmap */ | |
693 | void drbd_bm_set_all(struct drbd_conf *mdev) | |
694 | { | |
695 | struct drbd_bitmap *b = mdev->bitmap; | |
696 | ERR_IF(!b) return; | |
697 | ERR_IF(!b->bm_pages) return; | |
698 | ||
699 | spin_lock_irq(&b->bm_lock); | |
700 | bm_memset(b, 0, 0xff, b->bm_words); | |
701 | (void)bm_clear_surplus(b); | |
702 | b->bm_set = b->bm_bits; | |
703 | spin_unlock_irq(&b->bm_lock); | |
704 | } | |
705 | ||
706 | /* clear all bits in the bitmap */ | |
707 | void drbd_bm_clear_all(struct drbd_conf *mdev) | |
708 | { | |
709 | struct drbd_bitmap *b = mdev->bitmap; | |
710 | ERR_IF(!b) return; | |
711 | ERR_IF(!b->bm_pages) return; | |
712 | ||
713 | spin_lock_irq(&b->bm_lock); | |
714 | bm_memset(b, 0, 0, b->bm_words); | |
715 | b->bm_set = 0; | |
716 | spin_unlock_irq(&b->bm_lock); | |
717 | } | |
718 | ||
719 | static void bm_async_io_complete(struct bio *bio, int error) | |
720 | { | |
721 | struct drbd_bitmap *b = bio->bi_private; | |
722 | int uptodate = bio_flagged(bio, BIO_UPTODATE); | |
723 | ||
724 | ||
725 | /* strange behavior of some lower level drivers... | |
726 | * fail the request by clearing the uptodate flag, | |
727 | * but do not return any error?! | |
728 | * do we want to WARN() on this? */ | |
729 | if (!error && !uptodate) | |
730 | error = -EIO; | |
731 | ||
732 | if (error) { | |
733 | /* doh. what now? | |
734 | * for now, set all bits, and flag MD_IO_ERROR */ | |
735 | __set_bit(BM_MD_IO_ERROR, &b->bm_flags); | |
736 | } | |
737 | if (atomic_dec_and_test(&b->bm_async_io)) | |
738 | wake_up(&b->bm_io_wait); | |
739 | ||
740 | bio_put(bio); | |
741 | } | |
742 | ||
743 | static void bm_page_io_async(struct drbd_conf *mdev, struct drbd_bitmap *b, int page_nr, int rw) __must_hold(local) | |
744 | { | |
745 | /* we are process context. we always get a bio */ | |
746 | struct bio *bio = bio_alloc(GFP_KERNEL, 1); | |
747 | unsigned int len; | |
748 | sector_t on_disk_sector = | |
749 | mdev->ldev->md.md_offset + mdev->ldev->md.bm_offset; | |
750 | on_disk_sector += ((sector_t)page_nr) << (PAGE_SHIFT-9); | |
751 | ||
752 | /* this might happen with very small | |
753 | * flexible external meta data device */ | |
754 | len = min_t(unsigned int, PAGE_SIZE, | |
755 | (drbd_md_last_sector(mdev->ldev) - on_disk_sector + 1)<<9); | |
756 | ||
757 | bio->bi_bdev = mdev->ldev->md_bdev; | |
758 | bio->bi_sector = on_disk_sector; | |
759 | bio_add_page(bio, b->bm_pages[page_nr], len, 0); | |
760 | bio->bi_private = b; | |
761 | bio->bi_end_io = bm_async_io_complete; | |
762 | ||
763 | if (FAULT_ACTIVE(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) { | |
764 | bio->bi_rw |= rw; | |
765 | bio_endio(bio, -EIO); | |
766 | } else { | |
767 | submit_bio(rw, bio); | |
768 | } | |
769 | } | |
770 | ||
771 | # if defined(__LITTLE_ENDIAN) | |
772 | /* nothing to do, on disk == in memory */ | |
773 | # define bm_cpu_to_lel(x) ((void)0) | |
774 | # else | |
775 | void bm_cpu_to_lel(struct drbd_bitmap *b) | |
776 | { | |
777 | /* need to cpu_to_lel all the pages ... | |
778 | * this may be optimized by using | |
779 | * cpu_to_lel(-1) == -1 and cpu_to_lel(0) == 0; | |
780 | * the following is still not optimal, but better than nothing */ | |
781 | unsigned int i; | |
782 | unsigned long *p_addr, *bm; | |
783 | if (b->bm_set == 0) { | |
784 | /* no page at all; avoid swap if all is 0 */ | |
785 | i = b->bm_number_of_pages; | |
786 | } else if (b->bm_set == b->bm_bits) { | |
787 | /* only the last page */ | |
788 | i = b->bm_number_of_pages - 1; | |
789 | } else { | |
790 | /* all pages */ | |
791 | i = 0; | |
792 | } | |
793 | for (; i < b->bm_number_of_pages; i++) { | |
794 | p_addr = kmap_atomic(b->bm_pages[i], KM_USER0); | |
795 | for (bm = p_addr; bm < p_addr + PAGE_SIZE/sizeof(long); bm++) | |
796 | *bm = cpu_to_lel(*bm); | |
797 | kunmap_atomic(p_addr, KM_USER0); | |
798 | } | |
799 | } | |
800 | # endif | |
801 | /* lel_to_cpu == cpu_to_lel */ | |
802 | # define bm_lel_to_cpu(x) bm_cpu_to_lel(x) | |
803 | ||
804 | /* | |
805 | * bm_rw: read/write the whole bitmap from/to its on disk location. | |
806 | */ | |
807 | static int bm_rw(struct drbd_conf *mdev, int rw) __must_hold(local) | |
808 | { | |
809 | struct drbd_bitmap *b = mdev->bitmap; | |
810 | /* sector_t sector; */ | |
811 | int bm_words, num_pages, i; | |
812 | unsigned long now; | |
813 | char ppb[10]; | |
814 | int err = 0; | |
815 | ||
816 | WARN_ON(!bm_is_locked(b)); | |
817 | ||
818 | /* no spinlock here, the drbd_bm_lock should be enough! */ | |
819 | ||
820 | bm_words = drbd_bm_words(mdev); | |
821 | num_pages = (bm_words*sizeof(long) + PAGE_SIZE-1) >> PAGE_SHIFT; | |
822 | ||
823 | /* on disk bitmap is little endian */ | |
824 | if (rw == WRITE) | |
825 | bm_cpu_to_lel(b); | |
826 | ||
827 | now = jiffies; | |
828 | atomic_set(&b->bm_async_io, num_pages); | |
829 | __clear_bit(BM_MD_IO_ERROR, &b->bm_flags); | |
830 | ||
831 | /* let the layers below us try to merge these bios... */ | |
832 | for (i = 0; i < num_pages; i++) | |
833 | bm_page_io_async(mdev, b, i, rw); | |
834 | ||
835 | drbd_blk_run_queue(bdev_get_queue(mdev->ldev->md_bdev)); | |
836 | wait_event(b->bm_io_wait, atomic_read(&b->bm_async_io) == 0); | |
837 | ||
838 | if (test_bit(BM_MD_IO_ERROR, &b->bm_flags)) { | |
839 | dev_alert(DEV, "we had at least one MD IO ERROR during bitmap IO\n"); | |
840 | drbd_chk_io_error(mdev, 1, TRUE); | |
841 | err = -EIO; | |
842 | } | |
843 | ||
844 | now = jiffies; | |
845 | if (rw == WRITE) { | |
846 | /* swap back endianness */ | |
847 | bm_lel_to_cpu(b); | |
848 | /* flush bitmap to stable storage */ | |
849 | drbd_md_flush(mdev); | |
850 | } else /* rw == READ */ { | |
851 | /* just read, if necessary adjust endianness */ | |
852 | b->bm_set = bm_count_bits_swap_endian(b); | |
853 | dev_info(DEV, "recounting of set bits took additional %lu jiffies\n", | |
854 | jiffies - now); | |
855 | } | |
856 | now = b->bm_set; | |
857 | ||
858 | dev_info(DEV, "%s (%lu bits) marked out-of-sync by on disk bit-map.\n", | |
859 | ppsize(ppb, now << (BM_BLOCK_SHIFT-10)), now); | |
860 | ||
861 | return err; | |
862 | } | |
863 | ||
864 | /** | |
865 | * drbd_bm_read() - Read the whole bitmap from its on disk location. | |
866 | * @mdev: DRBD device. | |
867 | */ | |
868 | int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local) | |
869 | { | |
870 | return bm_rw(mdev, READ); | |
871 | } | |
872 | ||
873 | /** | |
874 | * drbd_bm_write() - Write the whole bitmap to its on disk location. | |
875 | * @mdev: DRBD device. | |
876 | */ | |
877 | int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local) | |
878 | { | |
879 | return bm_rw(mdev, WRITE); | |
880 | } | |
881 | ||
882 | /** | |
883 | * drbd_bm_write_sect: Writes a 512 (MD_SECTOR_SIZE) byte piece of the bitmap | |
884 | * @mdev: DRBD device. | |
885 | * @enr: Extent number in the resync lru (happens to be sector offset) | |
886 | * | |
887 | * The BM_EXT_SIZE is on purpose exactly the amount of the bitmap covered | |
888 | * by a single sector write. Therefore enr == sector offset from the | |
889 | * start of the bitmap. | |
890 | */ | |
891 | int drbd_bm_write_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local) | |
892 | { | |
893 | sector_t on_disk_sector = enr + mdev->ldev->md.md_offset | |
894 | + mdev->ldev->md.bm_offset; | |
895 | int bm_words, num_words, offset; | |
896 | int err = 0; | |
897 | ||
898 | mutex_lock(&mdev->md_io_mutex); | |
899 | bm_words = drbd_bm_words(mdev); | |
900 | offset = S2W(enr); /* word offset into bitmap */ | |
901 | num_words = min(S2W(1), bm_words - offset); | |
902 | if (num_words < S2W(1)) | |
903 | memset(page_address(mdev->md_io_page), 0, MD_SECTOR_SIZE); | |
904 | drbd_bm_get_lel(mdev, offset, num_words, | |
905 | page_address(mdev->md_io_page)); | |
906 | if (!drbd_md_sync_page_io(mdev, mdev->ldev, on_disk_sector, WRITE)) { | |
907 | int i; | |
908 | err = -EIO; | |
909 | dev_err(DEV, "IO ERROR writing bitmap sector %lu " | |
910 | "(meta-disk sector %llus)\n", | |
911 | enr, (unsigned long long)on_disk_sector); | |
912 | drbd_chk_io_error(mdev, 1, TRUE); | |
913 | for (i = 0; i < AL_EXT_PER_BM_SECT; i++) | |
914 | drbd_bm_ALe_set_all(mdev, enr*AL_EXT_PER_BM_SECT+i); | |
915 | } | |
916 | mdev->bm_writ_cnt++; | |
917 | mutex_unlock(&mdev->md_io_mutex); | |
918 | return err; | |
919 | } | |
920 | ||
921 | /* NOTE | |
922 | * find_first_bit returns int, we return unsigned long. | |
923 | * should not make much difference anyways, but ... | |
924 | * | |
925 | * this returns a bit number, NOT a sector! | |
926 | */ | |
927 | #define BPP_MASK ((1UL << (PAGE_SHIFT+3)) - 1) | |
928 | static unsigned long __bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo, | |
929 | const int find_zero_bit, const enum km_type km) | |
930 | { | |
931 | struct drbd_bitmap *b = mdev->bitmap; | |
932 | unsigned long i = -1UL; | |
933 | unsigned long *p_addr; | |
934 | unsigned long bit_offset; /* bit offset of the mapped page. */ | |
935 | ||
936 | if (bm_fo > b->bm_bits) { | |
937 | dev_err(DEV, "bm_fo=%lu bm_bits=%lu\n", bm_fo, b->bm_bits); | |
938 | } else { | |
939 | while (bm_fo < b->bm_bits) { | |
940 | unsigned long offset; | |
941 | bit_offset = bm_fo & ~BPP_MASK; /* bit offset of the page */ | |
942 | offset = bit_offset >> LN2_BPL; /* word offset of the page */ | |
943 | p_addr = __bm_map_paddr(b, offset, km); | |
944 | ||
945 | if (find_zero_bit) | |
946 | i = find_next_zero_bit(p_addr, PAGE_SIZE*8, bm_fo & BPP_MASK); | |
947 | else | |
948 | i = find_next_bit(p_addr, PAGE_SIZE*8, bm_fo & BPP_MASK); | |
949 | ||
950 | __bm_unmap(p_addr, km); | |
951 | if (i < PAGE_SIZE*8) { | |
952 | i = bit_offset + i; | |
953 | if (i >= b->bm_bits) | |
954 | break; | |
955 | goto found; | |
956 | } | |
957 | bm_fo = bit_offset + PAGE_SIZE*8; | |
958 | } | |
959 | i = -1UL; | |
960 | } | |
961 | found: | |
962 | return i; | |
963 | } | |
964 | ||
965 | static unsigned long bm_find_next(struct drbd_conf *mdev, | |
966 | unsigned long bm_fo, const int find_zero_bit) | |
967 | { | |
968 | struct drbd_bitmap *b = mdev->bitmap; | |
969 | unsigned long i = -1UL; | |
970 | ||
971 | ERR_IF(!b) return i; | |
972 | ERR_IF(!b->bm_pages) return i; | |
973 | ||
974 | spin_lock_irq(&b->bm_lock); | |
975 | if (bm_is_locked(b)) | |
976 | bm_print_lock_info(mdev); | |
977 | ||
978 | i = __bm_find_next(mdev, bm_fo, find_zero_bit, KM_IRQ1); | |
979 | ||
980 | spin_unlock_irq(&b->bm_lock); | |
981 | return i; | |
982 | } | |
983 | ||
984 | unsigned long drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo) | |
985 | { | |
986 | return bm_find_next(mdev, bm_fo, 0); | |
987 | } | |
988 | ||
989 | #if 0 | |
990 | /* not yet needed for anything. */ | |
991 | unsigned long drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo) | |
992 | { | |
993 | return bm_find_next(mdev, bm_fo, 1); | |
994 | } | |
995 | #endif | |
996 | ||
997 | /* does not spin_lock_irqsave. | |
998 | * you must take drbd_bm_lock() first */ | |
999 | unsigned long _drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo) | |
1000 | { | |
1001 | /* WARN_ON(!bm_is_locked(mdev)); */ | |
1002 | return __bm_find_next(mdev, bm_fo, 0, KM_USER1); | |
1003 | } | |
1004 | ||
1005 | unsigned long _drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo) | |
1006 | { | |
1007 | /* WARN_ON(!bm_is_locked(mdev)); */ | |
1008 | return __bm_find_next(mdev, bm_fo, 1, KM_USER1); | |
1009 | } | |
1010 | ||
1011 | /* returns number of bits actually changed. | |
1012 | * for val != 0, we change 0 -> 1, return code positive | |
1013 | * for val == 0, we change 1 -> 0, return code negative | |
1014 | * wants bitnr, not sector. | |
1015 | * expected to be called for only a few bits (e - s about BITS_PER_LONG). | |
1016 | * Must hold bitmap lock already. */ | |
1017 | int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, | |
1018 | unsigned long e, int val, const enum km_type km) | |
1019 | { | |
1020 | struct drbd_bitmap *b = mdev->bitmap; | |
1021 | unsigned long *p_addr = NULL; | |
1022 | unsigned long bitnr; | |
1023 | unsigned long last_page_nr = -1UL; | |
1024 | int c = 0; | |
1025 | ||
1026 | if (e >= b->bm_bits) { | |
1027 | dev_err(DEV, "ASSERT FAILED: bit_s=%lu bit_e=%lu bm_bits=%lu\n", | |
1028 | s, e, b->bm_bits); | |
1029 | e = b->bm_bits ? b->bm_bits -1 : 0; | |
1030 | } | |
1031 | for (bitnr = s; bitnr <= e; bitnr++) { | |
1032 | unsigned long offset = bitnr>>LN2_BPL; | |
1033 | unsigned long page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3); | |
1034 | if (page_nr != last_page_nr) { | |
1035 | if (p_addr) | |
1036 | __bm_unmap(p_addr, km); | |
1037 | p_addr = __bm_map_paddr(b, offset, km); | |
1038 | last_page_nr = page_nr; | |
1039 | } | |
1040 | if (val) | |
1041 | c += (0 == __test_and_set_bit(bitnr & BPP_MASK, p_addr)); | |
1042 | else | |
1043 | c -= (0 != __test_and_clear_bit(bitnr & BPP_MASK, p_addr)); | |
1044 | } | |
1045 | if (p_addr) | |
1046 | __bm_unmap(p_addr, km); | |
1047 | b->bm_set += c; | |
1048 | return c; | |
1049 | } | |
1050 | ||
1051 | /* returns number of bits actually changed. | |
1052 | * for val != 0, we change 0 -> 1, return code positive | |
1053 | * for val == 0, we change 1 -> 0, return code negative | |
1054 | * wants bitnr, not sector */ | |
1055 | int bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, | |
1056 | const unsigned long e, int val) | |
1057 | { | |
1058 | unsigned long flags; | |
1059 | struct drbd_bitmap *b = mdev->bitmap; | |
1060 | int c = 0; | |
1061 | ||
1062 | ERR_IF(!b) return 1; | |
1063 | ERR_IF(!b->bm_pages) return 0; | |
1064 | ||
1065 | spin_lock_irqsave(&b->bm_lock, flags); | |
1066 | if (bm_is_locked(b)) | |
1067 | bm_print_lock_info(mdev); | |
1068 | ||
1069 | c = __bm_change_bits_to(mdev, s, e, val, KM_IRQ1); | |
1070 | ||
1071 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
1072 | return c; | |
1073 | } | |
1074 | ||
1075 | /* returns number of bits changed 0 -> 1 */ | |
1076 | int drbd_bm_set_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e) | |
1077 | { | |
1078 | return bm_change_bits_to(mdev, s, e, 1); | |
1079 | } | |
1080 | ||
1081 | /* returns number of bits changed 1 -> 0 */ | |
1082 | int drbd_bm_clear_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e) | |
1083 | { | |
1084 | return -bm_change_bits_to(mdev, s, e, 0); | |
1085 | } | |
1086 | ||
1087 | /* sets all bits in full words, | |
1088 | * from first_word up to, but not including, last_word */ | |
1089 | static inline void bm_set_full_words_within_one_page(struct drbd_bitmap *b, | |
1090 | int page_nr, int first_word, int last_word) | |
1091 | { | |
1092 | int i; | |
1093 | int bits; | |
1094 | unsigned long *paddr = kmap_atomic(b->bm_pages[page_nr], KM_USER0); | |
1095 | for (i = first_word; i < last_word; i++) { | |
1096 | bits = hweight_long(paddr[i]); | |
1097 | paddr[i] = ~0UL; | |
1098 | b->bm_set += BITS_PER_LONG - bits; | |
1099 | } | |
1100 | kunmap_atomic(paddr, KM_USER0); | |
1101 | } | |
1102 | ||
1103 | /* Same thing as drbd_bm_set_bits, but without taking the spin_lock_irqsave. | |
1104 | * You must first drbd_bm_lock(). | |
1105 | * Can be called to set the whole bitmap in one go. | |
1106 | * Sets bits from s to e _inclusive_. */ | |
1107 | void _drbd_bm_set_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e) | |
1108 | { | |
1109 | /* First set_bit from the first bit (s) | |
1110 | * up to the next long boundary (sl), | |
1111 | * then assign full words up to the last long boundary (el), | |
1112 | * then set_bit up to and including the last bit (e). | |
1113 | * | |
1114 | * Do not use memset, because we must account for changes, | |
1115 | * so we need to loop over the words with hweight() anyways. | |
1116 | */ | |
1117 | unsigned long sl = ALIGN(s,BITS_PER_LONG); | |
1118 | unsigned long el = (e+1) & ~((unsigned long)BITS_PER_LONG-1); | |
1119 | int first_page; | |
1120 | int last_page; | |
1121 | int page_nr; | |
1122 | int first_word; | |
1123 | int last_word; | |
1124 | ||
1125 | if (e - s <= 3*BITS_PER_LONG) { | |
1126 | /* don't bother; el and sl may even be wrong. */ | |
1127 | __bm_change_bits_to(mdev, s, e, 1, KM_USER0); | |
1128 | return; | |
1129 | } | |
1130 | ||
1131 | /* difference is large enough that we can trust sl and el */ | |
1132 | ||
1133 | /* bits filling the current long */ | |
1134 | if (sl) | |
1135 | __bm_change_bits_to(mdev, s, sl-1, 1, KM_USER0); | |
1136 | ||
1137 | first_page = sl >> (3 + PAGE_SHIFT); | |
1138 | last_page = el >> (3 + PAGE_SHIFT); | |
1139 | ||
1140 | /* MLPP: modulo longs per page */ | |
1141 | /* LWPP: long words per page */ | |
1142 | first_word = MLPP(sl >> LN2_BPL); | |
1143 | last_word = LWPP; | |
1144 | ||
1145 | /* first and full pages, unless first page == last page */ | |
1146 | for (page_nr = first_page; page_nr < last_page; page_nr++) { | |
1147 | bm_set_full_words_within_one_page(mdev->bitmap, page_nr, first_word, last_word); | |
1148 | cond_resched(); | |
1149 | first_word = 0; | |
1150 | } | |
1151 | ||
1152 | /* last page (respectively only page, for first page == last page) */ | |
1153 | last_word = MLPP(el >> LN2_BPL); | |
1154 | bm_set_full_words_within_one_page(mdev->bitmap, last_page, first_word, last_word); | |
1155 | ||
1156 | /* possibly trailing bits. | |
1157 | * example: (e & 63) == 63, el will be e+1. | |
1158 | * if that even was the very last bit, | |
1159 | * it would trigger an assert in __bm_change_bits_to() | |
1160 | */ | |
1161 | if (el <= e) | |
1162 | __bm_change_bits_to(mdev, el, e, 1, KM_USER0); | |
1163 | } | |
1164 | ||
1165 | /* returns bit state | |
1166 | * wants bitnr, NOT sector. | |
1167 | * inherently racy... area needs to be locked by means of {al,rs}_lru | |
1168 | * 1 ... bit set | |
1169 | * 0 ... bit not set | |
1170 | * -1 ... first out of bounds access, stop testing for bits! | |
1171 | */ | |
1172 | int drbd_bm_test_bit(struct drbd_conf *mdev, const unsigned long bitnr) | |
1173 | { | |
1174 | unsigned long flags; | |
1175 | struct drbd_bitmap *b = mdev->bitmap; | |
1176 | unsigned long *p_addr; | |
1177 | int i; | |
1178 | ||
1179 | ERR_IF(!b) return 0; | |
1180 | ERR_IF(!b->bm_pages) return 0; | |
1181 | ||
1182 | spin_lock_irqsave(&b->bm_lock, flags); | |
1183 | if (bm_is_locked(b)) | |
1184 | bm_print_lock_info(mdev); | |
1185 | if (bitnr < b->bm_bits) { | |
1186 | unsigned long offset = bitnr>>LN2_BPL; | |
1187 | p_addr = bm_map_paddr(b, offset); | |
1188 | i = test_bit(bitnr & BPP_MASK, p_addr) ? 1 : 0; | |
1189 | bm_unmap(p_addr); | |
1190 | } else if (bitnr == b->bm_bits) { | |
1191 | i = -1; | |
1192 | } else { /* (bitnr > b->bm_bits) */ | |
1193 | dev_err(DEV, "bitnr=%lu > bm_bits=%lu\n", bitnr, b->bm_bits); | |
1194 | i = 0; | |
1195 | } | |
1196 | ||
1197 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
1198 | return i; | |
1199 | } | |
1200 | ||
1201 | /* returns number of bits set in the range [s, e] */ | |
1202 | int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e) | |
1203 | { | |
1204 | unsigned long flags; | |
1205 | struct drbd_bitmap *b = mdev->bitmap; | |
1206 | unsigned long *p_addr = NULL, page_nr = -1; | |
1207 | unsigned long bitnr; | |
1208 | int c = 0; | |
1209 | size_t w; | |
1210 | ||
1211 | /* If this is called without a bitmap, that is a bug. But just to be | |
1212 | * robust in case we screwed up elsewhere, in that case pretend there | |
1213 | * was one dirty bit in the requested area, so we won't try to do a | |
1214 | * local read there (no bitmap probably implies no disk) */ | |
1215 | ERR_IF(!b) return 1; | |
1216 | ERR_IF(!b->bm_pages) return 1; | |
1217 | ||
1218 | spin_lock_irqsave(&b->bm_lock, flags); | |
1219 | if (bm_is_locked(b)) | |
1220 | bm_print_lock_info(mdev); | |
1221 | for (bitnr = s; bitnr <= e; bitnr++) { | |
1222 | w = bitnr >> LN2_BPL; | |
1223 | if (page_nr != w >> (PAGE_SHIFT - LN2_BPL + 3)) { | |
1224 | page_nr = w >> (PAGE_SHIFT - LN2_BPL + 3); | |
1225 | if (p_addr) | |
1226 | bm_unmap(p_addr); | |
1227 | p_addr = bm_map_paddr(b, w); | |
1228 | } | |
1229 | ERR_IF (bitnr >= b->bm_bits) { | |
1230 | dev_err(DEV, "bitnr=%lu bm_bits=%lu\n", bitnr, b->bm_bits); | |
1231 | } else { | |
1232 | c += (0 != test_bit(bitnr - (page_nr << (PAGE_SHIFT+3)), p_addr)); | |
1233 | } | |
1234 | } | |
1235 | if (p_addr) | |
1236 | bm_unmap(p_addr); | |
1237 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
1238 | return c; | |
1239 | } | |
1240 | ||
1241 | ||
1242 | /* inherently racy... | |
1243 | * return value may be already out-of-date when this function returns. | |
1244 | * but the general usage is that this is only use during a cstate when bits are | |
1245 | * only cleared, not set, and typically only care for the case when the return | |
1246 | * value is zero, or we already "locked" this "bitmap extent" by other means. | |
1247 | * | |
1248 | * enr is bm-extent number, since we chose to name one sector (512 bytes) | |
1249 | * worth of the bitmap a "bitmap extent". | |
1250 | * | |
1251 | * TODO | |
1252 | * I think since we use it like a reference count, we should use the real | |
1253 | * reference count of some bitmap extent element from some lru instead... | |
1254 | * | |
1255 | */ | |
1256 | int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr) | |
1257 | { | |
1258 | struct drbd_bitmap *b = mdev->bitmap; | |
1259 | int count, s, e; | |
1260 | unsigned long flags; | |
1261 | unsigned long *p_addr, *bm; | |
1262 | ||
1263 | ERR_IF(!b) return 0; | |
1264 | ERR_IF(!b->bm_pages) return 0; | |
1265 | ||
1266 | spin_lock_irqsave(&b->bm_lock, flags); | |
1267 | if (bm_is_locked(b)) | |
1268 | bm_print_lock_info(mdev); | |
1269 | ||
1270 | s = S2W(enr); | |
1271 | e = min((size_t)S2W(enr+1), b->bm_words); | |
1272 | count = 0; | |
1273 | if (s < b->bm_words) { | |
1274 | int n = e-s; | |
1275 | p_addr = bm_map_paddr(b, s); | |
1276 | bm = p_addr + MLPP(s); | |
1277 | while (n--) | |
1278 | count += hweight_long(*bm++); | |
1279 | bm_unmap(p_addr); | |
1280 | } else { | |
1281 | dev_err(DEV, "start offset (%d) too large in drbd_bm_e_weight\n", s); | |
1282 | } | |
1283 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
1284 | return count; | |
1285 | } | |
1286 | ||
1287 | /* set all bits covered by the AL-extent al_enr */ | |
1288 | unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, unsigned long al_enr) | |
1289 | { | |
1290 | struct drbd_bitmap *b = mdev->bitmap; | |
1291 | unsigned long *p_addr, *bm; | |
1292 | unsigned long weight; | |
1293 | int count, s, e, i, do_now; | |
1294 | ERR_IF(!b) return 0; | |
1295 | ERR_IF(!b->bm_pages) return 0; | |
1296 | ||
1297 | spin_lock_irq(&b->bm_lock); | |
1298 | if (bm_is_locked(b)) | |
1299 | bm_print_lock_info(mdev); | |
1300 | weight = b->bm_set; | |
1301 | ||
1302 | s = al_enr * BM_WORDS_PER_AL_EXT; | |
1303 | e = min_t(size_t, s + BM_WORDS_PER_AL_EXT, b->bm_words); | |
1304 | /* assert that s and e are on the same page */ | |
1305 | D_ASSERT((e-1) >> (PAGE_SHIFT - LN2_BPL + 3) | |
1306 | == s >> (PAGE_SHIFT - LN2_BPL + 3)); | |
1307 | count = 0; | |
1308 | if (s < b->bm_words) { | |
1309 | i = do_now = e-s; | |
1310 | p_addr = bm_map_paddr(b, s); | |
1311 | bm = p_addr + MLPP(s); | |
1312 | while (i--) { | |
1313 | count += hweight_long(*bm); | |
1314 | *bm = -1UL; | |
1315 | bm++; | |
1316 | } | |
1317 | bm_unmap(p_addr); | |
1318 | b->bm_set += do_now*BITS_PER_LONG - count; | |
1319 | if (e == b->bm_words) | |
1320 | b->bm_set -= bm_clear_surplus(b); | |
1321 | } else { | |
1322 | dev_err(DEV, "start offset (%d) too large in drbd_bm_ALe_set_all\n", s); | |
1323 | } | |
1324 | weight = b->bm_set - weight; | |
1325 | spin_unlock_irq(&b->bm_lock); | |
1326 | return weight; | |
1327 | } |