Commit | Line | Data |
---|---|---|
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> | |
5a0e3ad6 | 29 | #include <linux/slab.h> |
b411b363 PR |
30 | #include <asm/kmap_types.h> |
31 | #include "drbd_int.h" | |
32 | ||
33 | /* OPAQUE outside this file! | |
34 | * interface defined in drbd_int.h | |
35 | ||
36 | * convention: | |
37 | * function name drbd_bm_... => used elsewhere, "public". | |
38 | * function name bm_... => internal to implementation, "private". | |
39 | ||
40 | * Note that since find_first_bit returns int, at the current granularity of | |
41 | * the bitmap (4KB per byte), this implementation "only" supports up to | |
42 | * 1<<(32+12) == 16 TB... | |
43 | */ | |
44 | ||
45 | /* | |
46 | * NOTE | |
47 | * Access to the *bm_pages is protected by bm_lock. | |
48 | * It is safe to read the other members within the lock. | |
49 | * | |
50 | * drbd_bm_set_bits is called from bio_endio callbacks, | |
51 | * We may be called with irq already disabled, | |
52 | * so we need spin_lock_irqsave(). | |
53 | * And we need the kmap_atomic. | |
54 | */ | |
55 | struct drbd_bitmap { | |
56 | struct page **bm_pages; | |
57 | spinlock_t bm_lock; | |
58 | /* WARNING unsigned long bm_*: | |
59 | * 32bit number of bit offset is just enough for 512 MB bitmap. | |
60 | * it will blow up if we make the bitmap bigger... | |
61 | * not that it makes much sense to have a bitmap that large, | |
62 | * rather change the granularity to 16k or 64k or something. | |
63 | * (that implies other problems, however...) | |
64 | */ | |
65 | unsigned long bm_set; /* nr of set bits; THINK maybe atomic_t? */ | |
66 | unsigned long bm_bits; | |
67 | size_t bm_words; | |
68 | size_t bm_number_of_pages; | |
69 | sector_t bm_dev_capacity; | |
8a03ae2a | 70 | struct mutex bm_change; /* serializes resize operations */ |
b411b363 PR |
71 | |
72 | atomic_t bm_async_io; | |
73 | wait_queue_head_t bm_io_wait; | |
74 | ||
75 | unsigned long bm_flags; | |
76 | ||
77 | /* debugging aid, in case we are still racy somewhere */ | |
78 | char *bm_why; | |
79 | struct task_struct *bm_task; | |
80 | }; | |
81 | ||
82 | /* definition of bits in bm_flags */ | |
83 | #define BM_LOCKED 0 | |
84 | #define BM_MD_IO_ERROR 1 | |
85 | #define BM_P_VMALLOCED 2 | |
86 | ||
b4ee79da | 87 | static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, |
fd76438c PR |
88 | unsigned long e, int val, const enum km_type km); |
89 | ||
b411b363 PR |
90 | static int bm_is_locked(struct drbd_bitmap *b) |
91 | { | |
92 | return test_bit(BM_LOCKED, &b->bm_flags); | |
93 | } | |
94 | ||
95 | #define bm_print_lock_info(m) __bm_print_lock_info(m, __func__) | |
96 | static void __bm_print_lock_info(struct drbd_conf *mdev, const char *func) | |
97 | { | |
98 | struct drbd_bitmap *b = mdev->bitmap; | |
99 | if (!__ratelimit(&drbd_ratelimit_state)) | |
100 | return; | |
101 | dev_err(DEV, "FIXME %s in %s, bitmap locked for '%s' by %s\n", | |
102 | current == mdev->receiver.task ? "receiver" : | |
103 | current == mdev->asender.task ? "asender" : | |
104 | current == mdev->worker.task ? "worker" : current->comm, | |
105 | func, b->bm_why ?: "?", | |
106 | b->bm_task == mdev->receiver.task ? "receiver" : | |
107 | b->bm_task == mdev->asender.task ? "asender" : | |
108 | b->bm_task == mdev->worker.task ? "worker" : "?"); | |
109 | } | |
110 | ||
111 | void drbd_bm_lock(struct drbd_conf *mdev, char *why) | |
112 | { | |
113 | struct drbd_bitmap *b = mdev->bitmap; | |
114 | int trylock_failed; | |
115 | ||
116 | if (!b) { | |
117 | dev_err(DEV, "FIXME no bitmap in drbd_bm_lock!?\n"); | |
118 | return; | |
119 | } | |
120 | ||
8a03ae2a | 121 | trylock_failed = !mutex_trylock(&b->bm_change); |
b411b363 PR |
122 | |
123 | if (trylock_failed) { | |
124 | dev_warn(DEV, "%s going to '%s' but bitmap already locked for '%s' by %s\n", | |
125 | current == mdev->receiver.task ? "receiver" : | |
126 | current == mdev->asender.task ? "asender" : | |
127 | current == mdev->worker.task ? "worker" : current->comm, | |
128 | why, b->bm_why ?: "?", | |
129 | b->bm_task == mdev->receiver.task ? "receiver" : | |
130 | b->bm_task == mdev->asender.task ? "asender" : | |
131 | b->bm_task == mdev->worker.task ? "worker" : "?"); | |
8a03ae2a | 132 | mutex_lock(&b->bm_change); |
b411b363 PR |
133 | } |
134 | if (__test_and_set_bit(BM_LOCKED, &b->bm_flags)) | |
135 | dev_err(DEV, "FIXME bitmap already locked in bm_lock\n"); | |
136 | ||
137 | b->bm_why = why; | |
138 | b->bm_task = current; | |
139 | } | |
140 | ||
141 | void drbd_bm_unlock(struct drbd_conf *mdev) | |
142 | { | |
143 | struct drbd_bitmap *b = mdev->bitmap; | |
144 | if (!b) { | |
145 | dev_err(DEV, "FIXME no bitmap in drbd_bm_unlock!?\n"); | |
146 | return; | |
147 | } | |
148 | ||
149 | if (!__test_and_clear_bit(BM_LOCKED, &mdev->bitmap->bm_flags)) | |
150 | dev_err(DEV, "FIXME bitmap not locked in bm_unlock\n"); | |
151 | ||
152 | b->bm_why = NULL; | |
153 | b->bm_task = NULL; | |
8a03ae2a | 154 | mutex_unlock(&b->bm_change); |
b411b363 PR |
155 | } |
156 | ||
157 | /* word offset to long pointer */ | |
158 | static unsigned long *__bm_map_paddr(struct drbd_bitmap *b, unsigned long offset, const enum km_type km) | |
159 | { | |
160 | struct page *page; | |
161 | unsigned long page_nr; | |
162 | ||
163 | /* page_nr = (word*sizeof(long)) >> PAGE_SHIFT; */ | |
164 | page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3); | |
165 | BUG_ON(page_nr >= b->bm_number_of_pages); | |
166 | page = b->bm_pages[page_nr]; | |
167 | ||
168 | return (unsigned long *) kmap_atomic(page, km); | |
169 | } | |
170 | ||
171 | static unsigned long * bm_map_paddr(struct drbd_bitmap *b, unsigned long offset) | |
172 | { | |
173 | return __bm_map_paddr(b, offset, KM_IRQ1); | |
174 | } | |
175 | ||
176 | static void __bm_unmap(unsigned long *p_addr, const enum km_type km) | |
177 | { | |
178 | kunmap_atomic(p_addr, km); | |
179 | }; | |
180 | ||
181 | static void bm_unmap(unsigned long *p_addr) | |
182 | { | |
183 | return __bm_unmap(p_addr, KM_IRQ1); | |
184 | } | |
185 | ||
186 | /* long word offset of _bitmap_ sector */ | |
187 | #define S2W(s) ((s)<<(BM_EXT_SHIFT-BM_BLOCK_SHIFT-LN2_BPL)) | |
188 | /* word offset from start of bitmap to word number _in_page_ | |
189 | * modulo longs per page | |
190 | #define MLPP(X) ((X) % (PAGE_SIZE/sizeof(long)) | |
191 | hm, well, Philipp thinks gcc might not optimze the % into & (... - 1) | |
192 | so do it explicitly: | |
193 | */ | |
194 | #define MLPP(X) ((X) & ((PAGE_SIZE/sizeof(long))-1)) | |
195 | ||
196 | /* Long words per page */ | |
197 | #define LWPP (PAGE_SIZE/sizeof(long)) | |
198 | ||
199 | /* | |
200 | * actually most functions herein should take a struct drbd_bitmap*, not a | |
201 | * struct drbd_conf*, but for the debug macros I like to have the mdev around | |
202 | * to be able to report device specific. | |
203 | */ | |
204 | ||
205 | static void bm_free_pages(struct page **pages, unsigned long number) | |
206 | { | |
207 | unsigned long i; | |
208 | if (!pages) | |
209 | return; | |
210 | ||
211 | for (i = 0; i < number; i++) { | |
212 | if (!pages[i]) { | |
213 | printk(KERN_ALERT "drbd: bm_free_pages tried to free " | |
214 | "a NULL pointer; i=%lu n=%lu\n", | |
215 | i, number); | |
216 | continue; | |
217 | } | |
218 | __free_page(pages[i]); | |
219 | pages[i] = NULL; | |
220 | } | |
221 | } | |
222 | ||
223 | static void bm_vk_free(void *ptr, int v) | |
224 | { | |
225 | if (v) | |
226 | vfree(ptr); | |
227 | else | |
228 | kfree(ptr); | |
229 | } | |
230 | ||
231 | /* | |
232 | * "have" and "want" are NUMBER OF PAGES. | |
233 | */ | |
234 | static struct page **bm_realloc_pages(struct drbd_bitmap *b, unsigned long want) | |
235 | { | |
236 | struct page **old_pages = b->bm_pages; | |
237 | struct page **new_pages, *page; | |
238 | unsigned int i, bytes, vmalloced = 0; | |
239 | unsigned long have = b->bm_number_of_pages; | |
240 | ||
241 | BUG_ON(have == 0 && old_pages != NULL); | |
242 | BUG_ON(have != 0 && old_pages == NULL); | |
243 | ||
244 | if (have == want) | |
245 | return old_pages; | |
246 | ||
247 | /* Trying kmalloc first, falling back to vmalloc. | |
248 | * GFP_KERNEL is ok, as this is done when a lower level disk is | |
249 | * "attached" to the drbd. Context is receiver thread or cqueue | |
250 | * thread. As we have no disk yet, we are not in the IO path, | |
251 | * not even the IO path of the peer. */ | |
252 | bytes = sizeof(struct page *)*want; | |
253 | new_pages = kmalloc(bytes, GFP_KERNEL); | |
254 | if (!new_pages) { | |
255 | new_pages = vmalloc(bytes); | |
256 | if (!new_pages) | |
257 | return NULL; | |
258 | vmalloced = 1; | |
259 | } | |
260 | ||
261 | memset(new_pages, 0, bytes); | |
262 | if (want >= have) { | |
263 | for (i = 0; i < have; i++) | |
264 | new_pages[i] = old_pages[i]; | |
265 | for (; i < want; i++) { | |
266 | page = alloc_page(GFP_HIGHUSER); | |
267 | if (!page) { | |
268 | bm_free_pages(new_pages + have, i - have); | |
269 | bm_vk_free(new_pages, vmalloced); | |
270 | return NULL; | |
271 | } | |
272 | new_pages[i] = page; | |
273 | } | |
274 | } else { | |
275 | for (i = 0; i < want; i++) | |
276 | new_pages[i] = old_pages[i]; | |
277 | /* NOT HERE, we are outside the spinlock! | |
278 | bm_free_pages(old_pages + want, have - want); | |
279 | */ | |
280 | } | |
281 | ||
282 | if (vmalloced) | |
283 | set_bit(BM_P_VMALLOCED, &b->bm_flags); | |
284 | else | |
285 | clear_bit(BM_P_VMALLOCED, &b->bm_flags); | |
286 | ||
287 | return new_pages; | |
288 | } | |
289 | ||
290 | /* | |
291 | * called on driver init only. TODO call when a device is created. | |
292 | * allocates the drbd_bitmap, and stores it in mdev->bitmap. | |
293 | */ | |
294 | int drbd_bm_init(struct drbd_conf *mdev) | |
295 | { | |
296 | struct drbd_bitmap *b = mdev->bitmap; | |
297 | WARN_ON(b != NULL); | |
298 | b = kzalloc(sizeof(struct drbd_bitmap), GFP_KERNEL); | |
299 | if (!b) | |
300 | return -ENOMEM; | |
301 | spin_lock_init(&b->bm_lock); | |
8a03ae2a | 302 | mutex_init(&b->bm_change); |
b411b363 PR |
303 | init_waitqueue_head(&b->bm_io_wait); |
304 | ||
305 | mdev->bitmap = b; | |
306 | ||
307 | return 0; | |
308 | } | |
309 | ||
310 | sector_t drbd_bm_capacity(struct drbd_conf *mdev) | |
311 | { | |
312 | ERR_IF(!mdev->bitmap) return 0; | |
313 | return mdev->bitmap->bm_dev_capacity; | |
314 | } | |
315 | ||
316 | /* called on driver unload. TODO: call when a device is destroyed. | |
317 | */ | |
318 | void drbd_bm_cleanup(struct drbd_conf *mdev) | |
319 | { | |
320 | ERR_IF (!mdev->bitmap) return; | |
321 | bm_free_pages(mdev->bitmap->bm_pages, mdev->bitmap->bm_number_of_pages); | |
322 | bm_vk_free(mdev->bitmap->bm_pages, test_bit(BM_P_VMALLOCED, &mdev->bitmap->bm_flags)); | |
323 | kfree(mdev->bitmap); | |
324 | mdev->bitmap = NULL; | |
325 | } | |
326 | ||
327 | /* | |
328 | * since (b->bm_bits % BITS_PER_LONG) != 0, | |
329 | * this masks out the remaining bits. | |
330 | * Returns the number of bits cleared. | |
331 | */ | |
332 | static int bm_clear_surplus(struct drbd_bitmap *b) | |
333 | { | |
334 | const unsigned long mask = (1UL << (b->bm_bits & (BITS_PER_LONG-1))) - 1; | |
335 | size_t w = b->bm_bits >> LN2_BPL; | |
336 | int cleared = 0; | |
337 | unsigned long *p_addr, *bm; | |
338 | ||
339 | p_addr = bm_map_paddr(b, w); | |
340 | bm = p_addr + MLPP(w); | |
341 | if (w < b->bm_words) { | |
342 | cleared = hweight_long(*bm & ~mask); | |
343 | *bm &= mask; | |
344 | w++; bm++; | |
345 | } | |
346 | ||
347 | if (w < b->bm_words) { | |
348 | cleared += hweight_long(*bm); | |
349 | *bm = 0; | |
350 | } | |
351 | bm_unmap(p_addr); | |
352 | return cleared; | |
353 | } | |
354 | ||
355 | static void bm_set_surplus(struct drbd_bitmap *b) | |
356 | { | |
357 | const unsigned long mask = (1UL << (b->bm_bits & (BITS_PER_LONG-1))) - 1; | |
358 | size_t w = b->bm_bits >> LN2_BPL; | |
359 | unsigned long *p_addr, *bm; | |
360 | ||
361 | p_addr = bm_map_paddr(b, w); | |
362 | bm = p_addr + MLPP(w); | |
363 | if (w < b->bm_words) { | |
364 | *bm |= ~mask; | |
365 | bm++; w++; | |
366 | } | |
367 | ||
368 | if (w < b->bm_words) { | |
369 | *bm = ~(0UL); | |
370 | } | |
371 | bm_unmap(p_addr); | |
372 | } | |
373 | ||
374 | static unsigned long __bm_count_bits(struct drbd_bitmap *b, const int swap_endian) | |
375 | { | |
376 | unsigned long *p_addr, *bm, offset = 0; | |
377 | unsigned long bits = 0; | |
378 | unsigned long i, do_now; | |
379 | ||
380 | while (offset < b->bm_words) { | |
381 | i = do_now = min_t(size_t, b->bm_words-offset, LWPP); | |
382 | p_addr = __bm_map_paddr(b, offset, KM_USER0); | |
383 | bm = p_addr + MLPP(offset); | |
384 | while (i--) { | |
385 | #ifndef __LITTLE_ENDIAN | |
386 | if (swap_endian) | |
387 | *bm = lel_to_cpu(*bm); | |
388 | #endif | |
389 | bits += hweight_long(*bm++); | |
390 | } | |
391 | __bm_unmap(p_addr, KM_USER0); | |
392 | offset += do_now; | |
393 | cond_resched(); | |
394 | } | |
395 | ||
396 | return bits; | |
397 | } | |
398 | ||
399 | static unsigned long bm_count_bits(struct drbd_bitmap *b) | |
400 | { | |
401 | return __bm_count_bits(b, 0); | |
402 | } | |
403 | ||
404 | static unsigned long bm_count_bits_swap_endian(struct drbd_bitmap *b) | |
405 | { | |
406 | return __bm_count_bits(b, 1); | |
407 | } | |
408 | ||
409 | /* offset and len in long words.*/ | |
410 | static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len) | |
411 | { | |
412 | unsigned long *p_addr, *bm; | |
413 | size_t do_now, end; | |
414 | ||
415 | #define BM_SECTORS_PER_BIT (BM_BLOCK_SIZE/512) | |
416 | ||
417 | end = offset + len; | |
418 | ||
419 | if (end > b->bm_words) { | |
420 | printk(KERN_ALERT "drbd: bm_memset end > bm_words\n"); | |
421 | return; | |
422 | } | |
423 | ||
424 | while (offset < end) { | |
425 | do_now = min_t(size_t, ALIGN(offset + 1, LWPP), end) - offset; | |
426 | p_addr = bm_map_paddr(b, offset); | |
427 | bm = p_addr + MLPP(offset); | |
428 | if (bm+do_now > p_addr + LWPP) { | |
429 | printk(KERN_ALERT "drbd: BUG BUG BUG! p_addr:%p bm:%p do_now:%d\n", | |
430 | p_addr, bm, (int)do_now); | |
431 | break; /* breaks to after catch_oob_access_end() only! */ | |
432 | } | |
433 | memset(bm, c, do_now * sizeof(long)); | |
434 | bm_unmap(p_addr); | |
435 | offset += do_now; | |
436 | } | |
437 | } | |
438 | ||
439 | /* | |
440 | * make sure the bitmap has enough room for the attached storage, | |
441 | * if necessary, resize. | |
442 | * called whenever we may have changed the device size. | |
443 | * returns -ENOMEM if we could not allocate enough memory, 0 on success. | |
444 | * In case this is actually a resize, we copy the old bitmap into the new one. | |
445 | * Otherwise, the bitmap is initialized to all bits set. | |
446 | */ | |
02d9a94b | 447 | int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits) |
b411b363 PR |
448 | { |
449 | struct drbd_bitmap *b = mdev->bitmap; | |
450 | unsigned long bits, words, owords, obits, *p_addr, *bm; | |
451 | unsigned long want, have, onpages; /* number of pages */ | |
452 | struct page **npages, **opages = NULL; | |
453 | int err = 0, growing; | |
454 | int opages_vmalloced; | |
455 | ||
456 | ERR_IF(!b) return -ENOMEM; | |
457 | ||
458 | drbd_bm_lock(mdev, "resize"); | |
459 | ||
460 | dev_info(DEV, "drbd_bm_resize called with capacity == %llu\n", | |
461 | (unsigned long long)capacity); | |
462 | ||
463 | if (capacity == b->bm_dev_capacity) | |
464 | goto out; | |
465 | ||
466 | opages_vmalloced = test_bit(BM_P_VMALLOCED, &b->bm_flags); | |
467 | ||
468 | if (capacity == 0) { | |
469 | spin_lock_irq(&b->bm_lock); | |
470 | opages = b->bm_pages; | |
471 | onpages = b->bm_number_of_pages; | |
472 | owords = b->bm_words; | |
473 | b->bm_pages = NULL; | |
474 | b->bm_number_of_pages = | |
475 | b->bm_set = | |
476 | b->bm_bits = | |
477 | b->bm_words = | |
478 | b->bm_dev_capacity = 0; | |
479 | spin_unlock_irq(&b->bm_lock); | |
480 | bm_free_pages(opages, onpages); | |
481 | bm_vk_free(opages, opages_vmalloced); | |
482 | goto out; | |
483 | } | |
484 | bits = BM_SECT_TO_BIT(ALIGN(capacity, BM_SECT_PER_BIT)); | |
485 | ||
486 | /* if we would use | |
487 | words = ALIGN(bits,BITS_PER_LONG) >> LN2_BPL; | |
488 | a 32bit host could present the wrong number of words | |
489 | to a 64bit host. | |
490 | */ | |
491 | words = ALIGN(bits, 64) >> LN2_BPL; | |
492 | ||
493 | if (get_ldev(mdev)) { | |
494 | D_ASSERT((u64)bits <= (((u64)mdev->ldev->md.md_size_sect-MD_BM_OFFSET) << 12)); | |
495 | put_ldev(mdev); | |
496 | } | |
497 | ||
498 | /* one extra long to catch off by one errors */ | |
499 | want = ALIGN((words+1)*sizeof(long), PAGE_SIZE) >> PAGE_SHIFT; | |
500 | have = b->bm_number_of_pages; | |
501 | if (want == have) { | |
502 | D_ASSERT(b->bm_pages != NULL); | |
503 | npages = b->bm_pages; | |
504 | } else { | |
505 | if (FAULT_ACTIVE(mdev, DRBD_FAULT_BM_ALLOC)) | |
506 | npages = NULL; | |
507 | else | |
508 | npages = bm_realloc_pages(b, want); | |
509 | } | |
510 | ||
511 | if (!npages) { | |
512 | err = -ENOMEM; | |
513 | goto out; | |
514 | } | |
515 | ||
516 | spin_lock_irq(&b->bm_lock); | |
517 | opages = b->bm_pages; | |
518 | owords = b->bm_words; | |
519 | obits = b->bm_bits; | |
520 | ||
521 | growing = bits > obits; | |
5223671b | 522 | if (opages && growing && set_new_bits) |
b411b363 PR |
523 | bm_set_surplus(b); |
524 | ||
525 | b->bm_pages = npages; | |
526 | b->bm_number_of_pages = want; | |
527 | b->bm_bits = bits; | |
528 | b->bm_words = words; | |
529 | b->bm_dev_capacity = capacity; | |
530 | ||
531 | if (growing) { | |
02d9a94b PR |
532 | if (set_new_bits) { |
533 | bm_memset(b, owords, 0xff, words-owords); | |
534 | b->bm_set += bits - obits; | |
535 | } else | |
536 | bm_memset(b, owords, 0x00, words-owords); | |
537 | ||
b411b363 PR |
538 | } |
539 | ||
540 | if (want < have) { | |
541 | /* implicit: (opages != NULL) && (opages != npages) */ | |
542 | bm_free_pages(opages + want, have - want); | |
543 | } | |
544 | ||
545 | p_addr = bm_map_paddr(b, words); | |
546 | bm = p_addr + MLPP(words); | |
547 | *bm = DRBD_MAGIC; | |
548 | bm_unmap(p_addr); | |
549 | ||
550 | (void)bm_clear_surplus(b); | |
551 | ||
552 | spin_unlock_irq(&b->bm_lock); | |
553 | if (opages != npages) | |
554 | bm_vk_free(opages, opages_vmalloced); | |
555 | if (!growing) | |
556 | b->bm_set = bm_count_bits(b); | |
557 | dev_info(DEV, "resync bitmap: bits=%lu words=%lu\n", bits, words); | |
558 | ||
559 | out: | |
560 | drbd_bm_unlock(mdev); | |
561 | return err; | |
562 | } | |
563 | ||
564 | /* inherently racy: | |
565 | * if not protected by other means, return value may be out of date when | |
566 | * leaving this function... | |
567 | * we still need to lock it, since it is important that this returns | |
568 | * bm_set == 0 precisely. | |
569 | * | |
570 | * maybe bm_set should be atomic_t ? | |
571 | */ | |
572 | static unsigned long _drbd_bm_total_weight(struct drbd_conf *mdev) | |
573 | { | |
574 | struct drbd_bitmap *b = mdev->bitmap; | |
575 | unsigned long s; | |
576 | unsigned long flags; | |
577 | ||
578 | ERR_IF(!b) return 0; | |
579 | ERR_IF(!b->bm_pages) return 0; | |
580 | ||
581 | spin_lock_irqsave(&b->bm_lock, flags); | |
582 | s = b->bm_set; | |
583 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
584 | ||
585 | return s; | |
586 | } | |
587 | ||
588 | unsigned long drbd_bm_total_weight(struct drbd_conf *mdev) | |
589 | { | |
590 | unsigned long s; | |
591 | /* if I don't have a disk, I don't know about out-of-sync status */ | |
592 | if (!get_ldev_if_state(mdev, D_NEGOTIATING)) | |
593 | return 0; | |
594 | s = _drbd_bm_total_weight(mdev); | |
595 | put_ldev(mdev); | |
596 | return s; | |
597 | } | |
598 | ||
599 | size_t drbd_bm_words(struct drbd_conf *mdev) | |
600 | { | |
601 | struct drbd_bitmap *b = mdev->bitmap; | |
602 | ERR_IF(!b) return 0; | |
603 | ERR_IF(!b->bm_pages) return 0; | |
604 | ||
605 | return b->bm_words; | |
606 | } | |
607 | ||
608 | unsigned long drbd_bm_bits(struct drbd_conf *mdev) | |
609 | { | |
610 | struct drbd_bitmap *b = mdev->bitmap; | |
611 | ERR_IF(!b) return 0; | |
612 | ||
613 | return b->bm_bits; | |
614 | } | |
615 | ||
616 | /* merge number words from buffer into the bitmap starting at offset. | |
617 | * buffer[i] is expected to be little endian unsigned long. | |
618 | * bitmap must be locked by drbd_bm_lock. | |
619 | * currently only used from receive_bitmap. | |
620 | */ | |
621 | void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number, | |
622 | unsigned long *buffer) | |
623 | { | |
624 | struct drbd_bitmap *b = mdev->bitmap; | |
625 | unsigned long *p_addr, *bm; | |
626 | unsigned long word, bits; | |
627 | size_t end, do_now; | |
628 | ||
629 | end = offset + number; | |
630 | ||
631 | ERR_IF(!b) return; | |
632 | ERR_IF(!b->bm_pages) return; | |
633 | if (number == 0) | |
634 | return; | |
635 | WARN_ON(offset >= b->bm_words); | |
636 | WARN_ON(end > b->bm_words); | |
637 | ||
638 | spin_lock_irq(&b->bm_lock); | |
639 | while (offset < end) { | |
640 | do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset; | |
641 | p_addr = bm_map_paddr(b, offset); | |
642 | bm = p_addr + MLPP(offset); | |
643 | offset += do_now; | |
644 | while (do_now--) { | |
645 | bits = hweight_long(*bm); | |
646 | word = *bm | lel_to_cpu(*buffer++); | |
647 | *bm++ = word; | |
648 | b->bm_set += hweight_long(word) - bits; | |
649 | } | |
650 | bm_unmap(p_addr); | |
651 | } | |
652 | /* with 32bit <-> 64bit cross-platform connect | |
653 | * this is only correct for current usage, | |
654 | * where we _know_ that we are 64 bit aligned, | |
655 | * and know that this function is used in this way, too... | |
656 | */ | |
657 | if (end == b->bm_words) | |
658 | b->bm_set -= bm_clear_surplus(b); | |
659 | ||
660 | spin_unlock_irq(&b->bm_lock); | |
661 | } | |
662 | ||
663 | /* copy number words from the bitmap starting at offset into the buffer. | |
664 | * buffer[i] will be little endian unsigned long. | |
665 | */ | |
666 | void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset, size_t number, | |
667 | unsigned long *buffer) | |
668 | { | |
669 | struct drbd_bitmap *b = mdev->bitmap; | |
670 | unsigned long *p_addr, *bm; | |
671 | size_t end, do_now; | |
672 | ||
673 | end = offset + number; | |
674 | ||
675 | ERR_IF(!b) return; | |
676 | ERR_IF(!b->bm_pages) return; | |
677 | ||
678 | spin_lock_irq(&b->bm_lock); | |
679 | if ((offset >= b->bm_words) || | |
680 | (end > b->bm_words) || | |
681 | (number <= 0)) | |
682 | dev_err(DEV, "offset=%lu number=%lu bm_words=%lu\n", | |
683 | (unsigned long) offset, | |
684 | (unsigned long) number, | |
685 | (unsigned long) b->bm_words); | |
686 | else { | |
687 | while (offset < end) { | |
688 | do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset; | |
689 | p_addr = bm_map_paddr(b, offset); | |
690 | bm = p_addr + MLPP(offset); | |
691 | offset += do_now; | |
692 | while (do_now--) | |
693 | *buffer++ = cpu_to_lel(*bm++); | |
694 | bm_unmap(p_addr); | |
695 | } | |
696 | } | |
697 | spin_unlock_irq(&b->bm_lock); | |
698 | } | |
699 | ||
700 | /* set all bits in the bitmap */ | |
701 | void drbd_bm_set_all(struct drbd_conf *mdev) | |
702 | { | |
703 | struct drbd_bitmap *b = mdev->bitmap; | |
704 | ERR_IF(!b) return; | |
705 | ERR_IF(!b->bm_pages) return; | |
706 | ||
707 | spin_lock_irq(&b->bm_lock); | |
708 | bm_memset(b, 0, 0xff, b->bm_words); | |
709 | (void)bm_clear_surplus(b); | |
710 | b->bm_set = b->bm_bits; | |
711 | spin_unlock_irq(&b->bm_lock); | |
712 | } | |
713 | ||
714 | /* clear all bits in the bitmap */ | |
715 | void drbd_bm_clear_all(struct drbd_conf *mdev) | |
716 | { | |
717 | struct drbd_bitmap *b = mdev->bitmap; | |
718 | ERR_IF(!b) return; | |
719 | ERR_IF(!b->bm_pages) return; | |
720 | ||
721 | spin_lock_irq(&b->bm_lock); | |
722 | bm_memset(b, 0, 0, b->bm_words); | |
723 | b->bm_set = 0; | |
724 | spin_unlock_irq(&b->bm_lock); | |
725 | } | |
726 | ||
727 | static void bm_async_io_complete(struct bio *bio, int error) | |
728 | { | |
729 | struct drbd_bitmap *b = bio->bi_private; | |
730 | int uptodate = bio_flagged(bio, BIO_UPTODATE); | |
731 | ||
732 | ||
733 | /* strange behavior of some lower level drivers... | |
734 | * fail the request by clearing the uptodate flag, | |
735 | * but do not return any error?! | |
736 | * do we want to WARN() on this? */ | |
737 | if (!error && !uptodate) | |
738 | error = -EIO; | |
739 | ||
740 | if (error) { | |
741 | /* doh. what now? | |
742 | * for now, set all bits, and flag MD_IO_ERROR */ | |
743 | __set_bit(BM_MD_IO_ERROR, &b->bm_flags); | |
744 | } | |
745 | if (atomic_dec_and_test(&b->bm_async_io)) | |
746 | wake_up(&b->bm_io_wait); | |
747 | ||
748 | bio_put(bio); | |
749 | } | |
750 | ||
751 | static void bm_page_io_async(struct drbd_conf *mdev, struct drbd_bitmap *b, int page_nr, int rw) __must_hold(local) | |
752 | { | |
753 | /* we are process context. we always get a bio */ | |
754 | struct bio *bio = bio_alloc(GFP_KERNEL, 1); | |
755 | unsigned int len; | |
756 | sector_t on_disk_sector = | |
757 | mdev->ldev->md.md_offset + mdev->ldev->md.bm_offset; | |
758 | on_disk_sector += ((sector_t)page_nr) << (PAGE_SHIFT-9); | |
759 | ||
760 | /* this might happen with very small | |
761 | * flexible external meta data device */ | |
762 | len = min_t(unsigned int, PAGE_SIZE, | |
763 | (drbd_md_last_sector(mdev->ldev) - on_disk_sector + 1)<<9); | |
764 | ||
765 | bio->bi_bdev = mdev->ldev->md_bdev; | |
766 | bio->bi_sector = on_disk_sector; | |
767 | bio_add_page(bio, b->bm_pages[page_nr], len, 0); | |
768 | bio->bi_private = b; | |
769 | bio->bi_end_io = bm_async_io_complete; | |
770 | ||
771 | if (FAULT_ACTIVE(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) { | |
772 | bio->bi_rw |= rw; | |
773 | bio_endio(bio, -EIO); | |
774 | } else { | |
775 | submit_bio(rw, bio); | |
776 | } | |
777 | } | |
778 | ||
779 | # if defined(__LITTLE_ENDIAN) | |
780 | /* nothing to do, on disk == in memory */ | |
781 | # define bm_cpu_to_lel(x) ((void)0) | |
782 | # else | |
b4ee79da | 783 | static void bm_cpu_to_lel(struct drbd_bitmap *b) |
b411b363 PR |
784 | { |
785 | /* need to cpu_to_lel all the pages ... | |
786 | * this may be optimized by using | |
787 | * cpu_to_lel(-1) == -1 and cpu_to_lel(0) == 0; | |
788 | * the following is still not optimal, but better than nothing */ | |
789 | unsigned int i; | |
790 | unsigned long *p_addr, *bm; | |
791 | if (b->bm_set == 0) { | |
792 | /* no page at all; avoid swap if all is 0 */ | |
793 | i = b->bm_number_of_pages; | |
794 | } else if (b->bm_set == b->bm_bits) { | |
795 | /* only the last page */ | |
796 | i = b->bm_number_of_pages - 1; | |
797 | } else { | |
798 | /* all pages */ | |
799 | i = 0; | |
800 | } | |
801 | for (; i < b->bm_number_of_pages; i++) { | |
802 | p_addr = kmap_atomic(b->bm_pages[i], KM_USER0); | |
803 | for (bm = p_addr; bm < p_addr + PAGE_SIZE/sizeof(long); bm++) | |
804 | *bm = cpu_to_lel(*bm); | |
805 | kunmap_atomic(p_addr, KM_USER0); | |
806 | } | |
807 | } | |
808 | # endif | |
809 | /* lel_to_cpu == cpu_to_lel */ | |
810 | # define bm_lel_to_cpu(x) bm_cpu_to_lel(x) | |
811 | ||
812 | /* | |
813 | * bm_rw: read/write the whole bitmap from/to its on disk location. | |
814 | */ | |
815 | static int bm_rw(struct drbd_conf *mdev, int rw) __must_hold(local) | |
816 | { | |
817 | struct drbd_bitmap *b = mdev->bitmap; | |
818 | /* sector_t sector; */ | |
819 | int bm_words, num_pages, i; | |
820 | unsigned long now; | |
821 | char ppb[10]; | |
822 | int err = 0; | |
823 | ||
824 | WARN_ON(!bm_is_locked(b)); | |
825 | ||
826 | /* no spinlock here, the drbd_bm_lock should be enough! */ | |
827 | ||
828 | bm_words = drbd_bm_words(mdev); | |
829 | num_pages = (bm_words*sizeof(long) + PAGE_SIZE-1) >> PAGE_SHIFT; | |
830 | ||
831 | /* on disk bitmap is little endian */ | |
832 | if (rw == WRITE) | |
833 | bm_cpu_to_lel(b); | |
834 | ||
835 | now = jiffies; | |
836 | atomic_set(&b->bm_async_io, num_pages); | |
837 | __clear_bit(BM_MD_IO_ERROR, &b->bm_flags); | |
838 | ||
839 | /* let the layers below us try to merge these bios... */ | |
840 | for (i = 0; i < num_pages; i++) | |
841 | bm_page_io_async(mdev, b, i, rw); | |
842 | ||
843 | drbd_blk_run_queue(bdev_get_queue(mdev->ldev->md_bdev)); | |
844 | wait_event(b->bm_io_wait, atomic_read(&b->bm_async_io) == 0); | |
845 | ||
846 | if (test_bit(BM_MD_IO_ERROR, &b->bm_flags)) { | |
847 | dev_alert(DEV, "we had at least one MD IO ERROR during bitmap IO\n"); | |
848 | drbd_chk_io_error(mdev, 1, TRUE); | |
849 | err = -EIO; | |
850 | } | |
851 | ||
852 | now = jiffies; | |
853 | if (rw == WRITE) { | |
854 | /* swap back endianness */ | |
855 | bm_lel_to_cpu(b); | |
856 | /* flush bitmap to stable storage */ | |
857 | drbd_md_flush(mdev); | |
858 | } else /* rw == READ */ { | |
859 | /* just read, if necessary adjust endianness */ | |
860 | b->bm_set = bm_count_bits_swap_endian(b); | |
861 | dev_info(DEV, "recounting of set bits took additional %lu jiffies\n", | |
862 | jiffies - now); | |
863 | } | |
864 | now = b->bm_set; | |
865 | ||
866 | dev_info(DEV, "%s (%lu bits) marked out-of-sync by on disk bit-map.\n", | |
867 | ppsize(ppb, now << (BM_BLOCK_SHIFT-10)), now); | |
868 | ||
869 | return err; | |
870 | } | |
871 | ||
872 | /** | |
873 | * drbd_bm_read() - Read the whole bitmap from its on disk location. | |
874 | * @mdev: DRBD device. | |
875 | */ | |
876 | int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local) | |
877 | { | |
878 | return bm_rw(mdev, READ); | |
879 | } | |
880 | ||
881 | /** | |
882 | * drbd_bm_write() - Write the whole bitmap to its on disk location. | |
883 | * @mdev: DRBD device. | |
884 | */ | |
885 | int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local) | |
886 | { | |
887 | return bm_rw(mdev, WRITE); | |
888 | } | |
889 | ||
890 | /** | |
891 | * drbd_bm_write_sect: Writes a 512 (MD_SECTOR_SIZE) byte piece of the bitmap | |
892 | * @mdev: DRBD device. | |
893 | * @enr: Extent number in the resync lru (happens to be sector offset) | |
894 | * | |
895 | * The BM_EXT_SIZE is on purpose exactly the amount of the bitmap covered | |
896 | * by a single sector write. Therefore enr == sector offset from the | |
897 | * start of the bitmap. | |
898 | */ | |
899 | int drbd_bm_write_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local) | |
900 | { | |
901 | sector_t on_disk_sector = enr + mdev->ldev->md.md_offset | |
902 | + mdev->ldev->md.bm_offset; | |
903 | int bm_words, num_words, offset; | |
904 | int err = 0; | |
905 | ||
906 | mutex_lock(&mdev->md_io_mutex); | |
907 | bm_words = drbd_bm_words(mdev); | |
908 | offset = S2W(enr); /* word offset into bitmap */ | |
909 | num_words = min(S2W(1), bm_words - offset); | |
910 | if (num_words < S2W(1)) | |
911 | memset(page_address(mdev->md_io_page), 0, MD_SECTOR_SIZE); | |
912 | drbd_bm_get_lel(mdev, offset, num_words, | |
913 | page_address(mdev->md_io_page)); | |
914 | if (!drbd_md_sync_page_io(mdev, mdev->ldev, on_disk_sector, WRITE)) { | |
915 | int i; | |
916 | err = -EIO; | |
917 | dev_err(DEV, "IO ERROR writing bitmap sector %lu " | |
918 | "(meta-disk sector %llus)\n", | |
919 | enr, (unsigned long long)on_disk_sector); | |
920 | drbd_chk_io_error(mdev, 1, TRUE); | |
921 | for (i = 0; i < AL_EXT_PER_BM_SECT; i++) | |
922 | drbd_bm_ALe_set_all(mdev, enr*AL_EXT_PER_BM_SECT+i); | |
923 | } | |
924 | mdev->bm_writ_cnt++; | |
925 | mutex_unlock(&mdev->md_io_mutex); | |
926 | return err; | |
927 | } | |
928 | ||
929 | /* NOTE | |
930 | * find_first_bit returns int, we return unsigned long. | |
931 | * should not make much difference anyways, but ... | |
932 | * | |
933 | * this returns a bit number, NOT a sector! | |
934 | */ | |
935 | #define BPP_MASK ((1UL << (PAGE_SHIFT+3)) - 1) | |
936 | static unsigned long __bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo, | |
937 | const int find_zero_bit, const enum km_type km) | |
938 | { | |
939 | struct drbd_bitmap *b = mdev->bitmap; | |
940 | unsigned long i = -1UL; | |
941 | unsigned long *p_addr; | |
942 | unsigned long bit_offset; /* bit offset of the mapped page. */ | |
943 | ||
944 | if (bm_fo > b->bm_bits) { | |
945 | dev_err(DEV, "bm_fo=%lu bm_bits=%lu\n", bm_fo, b->bm_bits); | |
946 | } else { | |
947 | while (bm_fo < b->bm_bits) { | |
948 | unsigned long offset; | |
949 | bit_offset = bm_fo & ~BPP_MASK; /* bit offset of the page */ | |
950 | offset = bit_offset >> LN2_BPL; /* word offset of the page */ | |
951 | p_addr = __bm_map_paddr(b, offset, km); | |
952 | ||
953 | if (find_zero_bit) | |
954 | i = find_next_zero_bit(p_addr, PAGE_SIZE*8, bm_fo & BPP_MASK); | |
955 | else | |
956 | i = find_next_bit(p_addr, PAGE_SIZE*8, bm_fo & BPP_MASK); | |
957 | ||
958 | __bm_unmap(p_addr, km); | |
959 | if (i < PAGE_SIZE*8) { | |
960 | i = bit_offset + i; | |
961 | if (i >= b->bm_bits) | |
962 | break; | |
963 | goto found; | |
964 | } | |
965 | bm_fo = bit_offset + PAGE_SIZE*8; | |
966 | } | |
967 | i = -1UL; | |
968 | } | |
969 | found: | |
970 | return i; | |
971 | } | |
972 | ||
973 | static unsigned long bm_find_next(struct drbd_conf *mdev, | |
974 | unsigned long bm_fo, const int find_zero_bit) | |
975 | { | |
976 | struct drbd_bitmap *b = mdev->bitmap; | |
977 | unsigned long i = -1UL; | |
978 | ||
979 | ERR_IF(!b) return i; | |
980 | ERR_IF(!b->bm_pages) return i; | |
981 | ||
982 | spin_lock_irq(&b->bm_lock); | |
983 | if (bm_is_locked(b)) | |
984 | bm_print_lock_info(mdev); | |
985 | ||
986 | i = __bm_find_next(mdev, bm_fo, find_zero_bit, KM_IRQ1); | |
987 | ||
988 | spin_unlock_irq(&b->bm_lock); | |
989 | return i; | |
990 | } | |
991 | ||
992 | unsigned long drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo) | |
993 | { | |
994 | return bm_find_next(mdev, bm_fo, 0); | |
995 | } | |
996 | ||
997 | #if 0 | |
998 | /* not yet needed for anything. */ | |
999 | unsigned long drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo) | |
1000 | { | |
1001 | return bm_find_next(mdev, bm_fo, 1); | |
1002 | } | |
1003 | #endif | |
1004 | ||
1005 | /* does not spin_lock_irqsave. | |
1006 | * you must take drbd_bm_lock() first */ | |
1007 | unsigned long _drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo) | |
1008 | { | |
1009 | /* WARN_ON(!bm_is_locked(mdev)); */ | |
1010 | return __bm_find_next(mdev, bm_fo, 0, KM_USER1); | |
1011 | } | |
1012 | ||
1013 | unsigned long _drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo) | |
1014 | { | |
1015 | /* WARN_ON(!bm_is_locked(mdev)); */ | |
1016 | return __bm_find_next(mdev, bm_fo, 1, KM_USER1); | |
1017 | } | |
1018 | ||
1019 | /* returns number of bits actually changed. | |
1020 | * for val != 0, we change 0 -> 1, return code positive | |
1021 | * for val == 0, we change 1 -> 0, return code negative | |
1022 | * wants bitnr, not sector. | |
1023 | * expected to be called for only a few bits (e - s about BITS_PER_LONG). | |
1024 | * Must hold bitmap lock already. */ | |
b4ee79da | 1025 | static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, |
b411b363 PR |
1026 | unsigned long e, int val, const enum km_type km) |
1027 | { | |
1028 | struct drbd_bitmap *b = mdev->bitmap; | |
1029 | unsigned long *p_addr = NULL; | |
1030 | unsigned long bitnr; | |
1031 | unsigned long last_page_nr = -1UL; | |
1032 | int c = 0; | |
1033 | ||
1034 | if (e >= b->bm_bits) { | |
1035 | dev_err(DEV, "ASSERT FAILED: bit_s=%lu bit_e=%lu bm_bits=%lu\n", | |
1036 | s, e, b->bm_bits); | |
1037 | e = b->bm_bits ? b->bm_bits -1 : 0; | |
1038 | } | |
1039 | for (bitnr = s; bitnr <= e; bitnr++) { | |
1040 | unsigned long offset = bitnr>>LN2_BPL; | |
1041 | unsigned long page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3); | |
1042 | if (page_nr != last_page_nr) { | |
1043 | if (p_addr) | |
1044 | __bm_unmap(p_addr, km); | |
1045 | p_addr = __bm_map_paddr(b, offset, km); | |
1046 | last_page_nr = page_nr; | |
1047 | } | |
1048 | if (val) | |
1049 | c += (0 == __test_and_set_bit(bitnr & BPP_MASK, p_addr)); | |
1050 | else | |
1051 | c -= (0 != __test_and_clear_bit(bitnr & BPP_MASK, p_addr)); | |
1052 | } | |
1053 | if (p_addr) | |
1054 | __bm_unmap(p_addr, km); | |
1055 | b->bm_set += c; | |
1056 | return c; | |
1057 | } | |
1058 | ||
1059 | /* returns number of bits actually changed. | |
1060 | * for val != 0, we change 0 -> 1, return code positive | |
1061 | * for val == 0, we change 1 -> 0, return code negative | |
1062 | * wants bitnr, not sector */ | |
b4ee79da | 1063 | static int bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, |
b411b363 PR |
1064 | const unsigned long e, int val) |
1065 | { | |
1066 | unsigned long flags; | |
1067 | struct drbd_bitmap *b = mdev->bitmap; | |
1068 | int c = 0; | |
1069 | ||
1070 | ERR_IF(!b) return 1; | |
1071 | ERR_IF(!b->bm_pages) return 0; | |
1072 | ||
1073 | spin_lock_irqsave(&b->bm_lock, flags); | |
1074 | if (bm_is_locked(b)) | |
1075 | bm_print_lock_info(mdev); | |
1076 | ||
1077 | c = __bm_change_bits_to(mdev, s, e, val, KM_IRQ1); | |
1078 | ||
1079 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
1080 | return c; | |
1081 | } | |
1082 | ||
1083 | /* returns number of bits changed 0 -> 1 */ | |
1084 | int drbd_bm_set_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e) | |
1085 | { | |
1086 | return bm_change_bits_to(mdev, s, e, 1); | |
1087 | } | |
1088 | ||
1089 | /* returns number of bits changed 1 -> 0 */ | |
1090 | int drbd_bm_clear_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e) | |
1091 | { | |
1092 | return -bm_change_bits_to(mdev, s, e, 0); | |
1093 | } | |
1094 | ||
1095 | /* sets all bits in full words, | |
1096 | * from first_word up to, but not including, last_word */ | |
1097 | static inline void bm_set_full_words_within_one_page(struct drbd_bitmap *b, | |
1098 | int page_nr, int first_word, int last_word) | |
1099 | { | |
1100 | int i; | |
1101 | int bits; | |
1102 | unsigned long *paddr = kmap_atomic(b->bm_pages[page_nr], KM_USER0); | |
1103 | for (i = first_word; i < last_word; i++) { | |
1104 | bits = hweight_long(paddr[i]); | |
1105 | paddr[i] = ~0UL; | |
1106 | b->bm_set += BITS_PER_LONG - bits; | |
1107 | } | |
1108 | kunmap_atomic(paddr, KM_USER0); | |
1109 | } | |
1110 | ||
1111 | /* Same thing as drbd_bm_set_bits, but without taking the spin_lock_irqsave. | |
1112 | * You must first drbd_bm_lock(). | |
1113 | * Can be called to set the whole bitmap in one go. | |
1114 | * Sets bits from s to e _inclusive_. */ | |
1115 | void _drbd_bm_set_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e) | |
1116 | { | |
1117 | /* First set_bit from the first bit (s) | |
1118 | * up to the next long boundary (sl), | |
1119 | * then assign full words up to the last long boundary (el), | |
1120 | * then set_bit up to and including the last bit (e). | |
1121 | * | |
1122 | * Do not use memset, because we must account for changes, | |
1123 | * so we need to loop over the words with hweight() anyways. | |
1124 | */ | |
1125 | unsigned long sl = ALIGN(s,BITS_PER_LONG); | |
1126 | unsigned long el = (e+1) & ~((unsigned long)BITS_PER_LONG-1); | |
1127 | int first_page; | |
1128 | int last_page; | |
1129 | int page_nr; | |
1130 | int first_word; | |
1131 | int last_word; | |
1132 | ||
1133 | if (e - s <= 3*BITS_PER_LONG) { | |
1134 | /* don't bother; el and sl may even be wrong. */ | |
1135 | __bm_change_bits_to(mdev, s, e, 1, KM_USER0); | |
1136 | return; | |
1137 | } | |
1138 | ||
1139 | /* difference is large enough that we can trust sl and el */ | |
1140 | ||
1141 | /* bits filling the current long */ | |
1142 | if (sl) | |
1143 | __bm_change_bits_to(mdev, s, sl-1, 1, KM_USER0); | |
1144 | ||
1145 | first_page = sl >> (3 + PAGE_SHIFT); | |
1146 | last_page = el >> (3 + PAGE_SHIFT); | |
1147 | ||
1148 | /* MLPP: modulo longs per page */ | |
1149 | /* LWPP: long words per page */ | |
1150 | first_word = MLPP(sl >> LN2_BPL); | |
1151 | last_word = LWPP; | |
1152 | ||
1153 | /* first and full pages, unless first page == last page */ | |
1154 | for (page_nr = first_page; page_nr < last_page; page_nr++) { | |
1155 | bm_set_full_words_within_one_page(mdev->bitmap, page_nr, first_word, last_word); | |
1156 | cond_resched(); | |
1157 | first_word = 0; | |
1158 | } | |
1159 | ||
1160 | /* last page (respectively only page, for first page == last page) */ | |
1161 | last_word = MLPP(el >> LN2_BPL); | |
1162 | bm_set_full_words_within_one_page(mdev->bitmap, last_page, first_word, last_word); | |
1163 | ||
1164 | /* possibly trailing bits. | |
1165 | * example: (e & 63) == 63, el will be e+1. | |
1166 | * if that even was the very last bit, | |
1167 | * it would trigger an assert in __bm_change_bits_to() | |
1168 | */ | |
1169 | if (el <= e) | |
1170 | __bm_change_bits_to(mdev, el, e, 1, KM_USER0); | |
1171 | } | |
1172 | ||
1173 | /* returns bit state | |
1174 | * wants bitnr, NOT sector. | |
1175 | * inherently racy... area needs to be locked by means of {al,rs}_lru | |
1176 | * 1 ... bit set | |
1177 | * 0 ... bit not set | |
1178 | * -1 ... first out of bounds access, stop testing for bits! | |
1179 | */ | |
1180 | int drbd_bm_test_bit(struct drbd_conf *mdev, const unsigned long bitnr) | |
1181 | { | |
1182 | unsigned long flags; | |
1183 | struct drbd_bitmap *b = mdev->bitmap; | |
1184 | unsigned long *p_addr; | |
1185 | int i; | |
1186 | ||
1187 | ERR_IF(!b) return 0; | |
1188 | ERR_IF(!b->bm_pages) return 0; | |
1189 | ||
1190 | spin_lock_irqsave(&b->bm_lock, flags); | |
1191 | if (bm_is_locked(b)) | |
1192 | bm_print_lock_info(mdev); | |
1193 | if (bitnr < b->bm_bits) { | |
1194 | unsigned long offset = bitnr>>LN2_BPL; | |
1195 | p_addr = bm_map_paddr(b, offset); | |
1196 | i = test_bit(bitnr & BPP_MASK, p_addr) ? 1 : 0; | |
1197 | bm_unmap(p_addr); | |
1198 | } else if (bitnr == b->bm_bits) { | |
1199 | i = -1; | |
1200 | } else { /* (bitnr > b->bm_bits) */ | |
1201 | dev_err(DEV, "bitnr=%lu > bm_bits=%lu\n", bitnr, b->bm_bits); | |
1202 | i = 0; | |
1203 | } | |
1204 | ||
1205 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
1206 | return i; | |
1207 | } | |
1208 | ||
1209 | /* returns number of bits set in the range [s, e] */ | |
1210 | int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e) | |
1211 | { | |
1212 | unsigned long flags; | |
1213 | struct drbd_bitmap *b = mdev->bitmap; | |
1214 | unsigned long *p_addr = NULL, page_nr = -1; | |
1215 | unsigned long bitnr; | |
1216 | int c = 0; | |
1217 | size_t w; | |
1218 | ||
1219 | /* If this is called without a bitmap, that is a bug. But just to be | |
1220 | * robust in case we screwed up elsewhere, in that case pretend there | |
1221 | * was one dirty bit in the requested area, so we won't try to do a | |
1222 | * local read there (no bitmap probably implies no disk) */ | |
1223 | ERR_IF(!b) return 1; | |
1224 | ERR_IF(!b->bm_pages) return 1; | |
1225 | ||
1226 | spin_lock_irqsave(&b->bm_lock, flags); | |
1227 | if (bm_is_locked(b)) | |
1228 | bm_print_lock_info(mdev); | |
1229 | for (bitnr = s; bitnr <= e; bitnr++) { | |
1230 | w = bitnr >> LN2_BPL; | |
1231 | if (page_nr != w >> (PAGE_SHIFT - LN2_BPL + 3)) { | |
1232 | page_nr = w >> (PAGE_SHIFT - LN2_BPL + 3); | |
1233 | if (p_addr) | |
1234 | bm_unmap(p_addr); | |
1235 | p_addr = bm_map_paddr(b, w); | |
1236 | } | |
1237 | ERR_IF (bitnr >= b->bm_bits) { | |
1238 | dev_err(DEV, "bitnr=%lu bm_bits=%lu\n", bitnr, b->bm_bits); | |
1239 | } else { | |
1240 | c += (0 != test_bit(bitnr - (page_nr << (PAGE_SHIFT+3)), p_addr)); | |
1241 | } | |
1242 | } | |
1243 | if (p_addr) | |
1244 | bm_unmap(p_addr); | |
1245 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
1246 | return c; | |
1247 | } | |
1248 | ||
1249 | ||
1250 | /* inherently racy... | |
1251 | * return value may be already out-of-date when this function returns. | |
1252 | * but the general usage is that this is only use during a cstate when bits are | |
1253 | * only cleared, not set, and typically only care for the case when the return | |
1254 | * value is zero, or we already "locked" this "bitmap extent" by other means. | |
1255 | * | |
1256 | * enr is bm-extent number, since we chose to name one sector (512 bytes) | |
1257 | * worth of the bitmap a "bitmap extent". | |
1258 | * | |
1259 | * TODO | |
1260 | * I think since we use it like a reference count, we should use the real | |
1261 | * reference count of some bitmap extent element from some lru instead... | |
1262 | * | |
1263 | */ | |
1264 | int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr) | |
1265 | { | |
1266 | struct drbd_bitmap *b = mdev->bitmap; | |
1267 | int count, s, e; | |
1268 | unsigned long flags; | |
1269 | unsigned long *p_addr, *bm; | |
1270 | ||
1271 | ERR_IF(!b) return 0; | |
1272 | ERR_IF(!b->bm_pages) return 0; | |
1273 | ||
1274 | spin_lock_irqsave(&b->bm_lock, flags); | |
1275 | if (bm_is_locked(b)) | |
1276 | bm_print_lock_info(mdev); | |
1277 | ||
1278 | s = S2W(enr); | |
1279 | e = min((size_t)S2W(enr+1), b->bm_words); | |
1280 | count = 0; | |
1281 | if (s < b->bm_words) { | |
1282 | int n = e-s; | |
1283 | p_addr = bm_map_paddr(b, s); | |
1284 | bm = p_addr + MLPP(s); | |
1285 | while (n--) | |
1286 | count += hweight_long(*bm++); | |
1287 | bm_unmap(p_addr); | |
1288 | } else { | |
1289 | dev_err(DEV, "start offset (%d) too large in drbd_bm_e_weight\n", s); | |
1290 | } | |
1291 | spin_unlock_irqrestore(&b->bm_lock, flags); | |
1292 | return count; | |
1293 | } | |
1294 | ||
1295 | /* set all bits covered by the AL-extent al_enr */ | |
1296 | unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, unsigned long al_enr) | |
1297 | { | |
1298 | struct drbd_bitmap *b = mdev->bitmap; | |
1299 | unsigned long *p_addr, *bm; | |
1300 | unsigned long weight; | |
1301 | int count, s, e, i, do_now; | |
1302 | ERR_IF(!b) return 0; | |
1303 | ERR_IF(!b->bm_pages) return 0; | |
1304 | ||
1305 | spin_lock_irq(&b->bm_lock); | |
1306 | if (bm_is_locked(b)) | |
1307 | bm_print_lock_info(mdev); | |
1308 | weight = b->bm_set; | |
1309 | ||
1310 | s = al_enr * BM_WORDS_PER_AL_EXT; | |
1311 | e = min_t(size_t, s + BM_WORDS_PER_AL_EXT, b->bm_words); | |
1312 | /* assert that s and e are on the same page */ | |
1313 | D_ASSERT((e-1) >> (PAGE_SHIFT - LN2_BPL + 3) | |
1314 | == s >> (PAGE_SHIFT - LN2_BPL + 3)); | |
1315 | count = 0; | |
1316 | if (s < b->bm_words) { | |
1317 | i = do_now = e-s; | |
1318 | p_addr = bm_map_paddr(b, s); | |
1319 | bm = p_addr + MLPP(s); | |
1320 | while (i--) { | |
1321 | count += hweight_long(*bm); | |
1322 | *bm = -1UL; | |
1323 | bm++; | |
1324 | } | |
1325 | bm_unmap(p_addr); | |
1326 | b->bm_set += do_now*BITS_PER_LONG - count; | |
1327 | if (e == b->bm_words) | |
1328 | b->bm_set -= bm_clear_surplus(b); | |
1329 | } else { | |
1330 | dev_err(DEV, "start offset (%d) too large in drbd_bm_ALe_set_all\n", s); | |
1331 | } | |
1332 | weight = b->bm_set - weight; | |
1333 | spin_unlock_irq(&b->bm_lock); | |
1334 | return weight; | |
1335 | } |