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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
4 *
5 * bitmap_create - sets up the bitmap structure
6 * bitmap_destroy - destroys the bitmap structure
7 *
8 * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
9 * - added disk storage for bitmap
10 * - changes to allow various bitmap chunk sizes
11 */
12
13/*
14 * Still to do:
15 *
16 * flush after percent set rather than just time based. (maybe both).
17 */
18
19#include <linux/blkdev.h>
20#include <linux/module.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/init.h>
24#include <linux/timer.h>
25#include <linux/sched.h>
26#include <linux/list.h>
27#include <linux/file.h>
28#include <linux/mount.h>
29#include <linux/buffer_head.h>
30#include <linux/seq_file.h>
31#include <trace/events/block.h>
32#include "md.h"
33#include "md-bitmap.h"
34
35static inline char *bmname(struct bitmap *bitmap)
36{
37 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
38}
39
40/*
41 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
42 *
43 * 1) check to see if this page is allocated, if it's not then try to alloc
44 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
45 * page pointer directly as a counter
46 *
47 * if we find our page, we increment the page's refcount so that it stays
48 * allocated while we're using it
49 */
50static int md_bitmap_checkpage(struct bitmap_counts *bitmap,
51 unsigned long page, int create, int no_hijack)
52__releases(bitmap->lock)
53__acquires(bitmap->lock)
54{
55 unsigned char *mappage;
56
57 if (page >= bitmap->pages) {
58 /* This can happen if bitmap_start_sync goes beyond
59 * End-of-device while looking for a whole page.
60 * It is harmless.
61 */
62 return -EINVAL;
63 }
64
65 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
66 return 0;
67
68 if (bitmap->bp[page].map) /* page is already allocated, just return */
69 return 0;
70
71 if (!create)
72 return -ENOENT;
73
74 /* this page has not been allocated yet */
75
76 spin_unlock_irq(&bitmap->lock);
77 /* It is possible that this is being called inside a
78 * prepare_to_wait/finish_wait loop from raid5c:make_request().
79 * In general it is not permitted to sleep in that context as it
80 * can cause the loop to spin freely.
81 * That doesn't apply here as we can only reach this point
82 * once with any loop.
83 * When this function completes, either bp[page].map or
84 * bp[page].hijacked. In either case, this function will
85 * abort before getting to this point again. So there is
86 * no risk of a free-spin, and so it is safe to assert
87 * that sleeping here is allowed.
88 */
89 sched_annotate_sleep();
90 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
91 spin_lock_irq(&bitmap->lock);
92
93 if (mappage == NULL) {
94 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
95 /* We don't support hijack for cluster raid */
96 if (no_hijack)
97 return -ENOMEM;
98 /* failed - set the hijacked flag so that we can use the
99 * pointer as a counter */
100 if (!bitmap->bp[page].map)
101 bitmap->bp[page].hijacked = 1;
102 } else if (bitmap->bp[page].map ||
103 bitmap->bp[page].hijacked) {
104 /* somebody beat us to getting the page */
105 kfree(mappage);
106 } else {
107
108 /* no page was in place and we have one, so install it */
109
110 bitmap->bp[page].map = mappage;
111 bitmap->missing_pages--;
112 }
113 return 0;
114}
115
116/* if page is completely empty, put it back on the free list, or dealloc it */
117/* if page was hijacked, unmark the flag so it might get alloced next time */
118/* Note: lock should be held when calling this */
119static void md_bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
120{
121 char *ptr;
122
123 if (bitmap->bp[page].count) /* page is still busy */
124 return;
125
126 /* page is no longer in use, it can be released */
127
128 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
129 bitmap->bp[page].hijacked = 0;
130 bitmap->bp[page].map = NULL;
131 } else {
132 /* normal case, free the page */
133 ptr = bitmap->bp[page].map;
134 bitmap->bp[page].map = NULL;
135 bitmap->missing_pages++;
136 kfree(ptr);
137 }
138}
139
140/*
141 * bitmap file handling - read and write the bitmap file and its superblock
142 */
143
144/*
145 * basic page I/O operations
146 */
147
148/* IO operations when bitmap is stored near all superblocks */
149static int read_sb_page(struct mddev *mddev, loff_t offset,
150 struct page *page,
151 unsigned long index, int size)
152{
153 /* choose a good rdev and read the page from there */
154
155 struct md_rdev *rdev;
156 sector_t target;
157
158 rdev_for_each(rdev, mddev) {
159 if (! test_bit(In_sync, &rdev->flags)
160 || test_bit(Faulty, &rdev->flags)
161 || test_bit(Bitmap_sync, &rdev->flags))
162 continue;
163
164 target = offset + index * (PAGE_SIZE/512);
165
166 if (sync_page_io(rdev, target,
167 roundup(size, bdev_logical_block_size(rdev->bdev)),
168 page, REQ_OP_READ, 0, true)) {
169 page->index = index;
170 return 0;
171 }
172 }
173 return -EIO;
174}
175
176static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
177{
178 /* Iterate the disks of an mddev, using rcu to protect access to the
179 * linked list, and raising the refcount of devices we return to ensure
180 * they don't disappear while in use.
181 * As devices are only added or removed when raid_disk is < 0 and
182 * nr_pending is 0 and In_sync is clear, the entries we return will
183 * still be in the same position on the list when we re-enter
184 * list_for_each_entry_continue_rcu.
185 *
186 * Note that if entered with 'rdev == NULL' to start at the
187 * beginning, we temporarily assign 'rdev' to an address which
188 * isn't really an rdev, but which can be used by
189 * list_for_each_entry_continue_rcu() to find the first entry.
190 */
191 rcu_read_lock();
192 if (rdev == NULL)
193 /* start at the beginning */
194 rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
195 else {
196 /* release the previous rdev and start from there. */
197 rdev_dec_pending(rdev, mddev);
198 }
199 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
200 if (rdev->raid_disk >= 0 &&
201 !test_bit(Faulty, &rdev->flags)) {
202 /* this is a usable devices */
203 atomic_inc(&rdev->nr_pending);
204 rcu_read_unlock();
205 return rdev;
206 }
207 }
208 rcu_read_unlock();
209 return NULL;
210}
211
212static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
213{
214 struct md_rdev *rdev;
215 struct block_device *bdev;
216 struct mddev *mddev = bitmap->mddev;
217 struct bitmap_storage *store = &bitmap->storage;
218
219restart:
220 rdev = NULL;
221 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
222 int size = PAGE_SIZE;
223 loff_t offset = mddev->bitmap_info.offset;
224
225 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
226
227 if (page->index == store->file_pages-1) {
228 int last_page_size = store->bytes & (PAGE_SIZE-1);
229 if (last_page_size == 0)
230 last_page_size = PAGE_SIZE;
231 size = roundup(last_page_size,
232 bdev_logical_block_size(bdev));
233 }
234 /* Just make sure we aren't corrupting data or
235 * metadata
236 */
237 if (mddev->external) {
238 /* Bitmap could be anywhere. */
239 if (rdev->sb_start + offset + (page->index
240 * (PAGE_SIZE/512))
241 > rdev->data_offset
242 &&
243 rdev->sb_start + offset
244 < (rdev->data_offset + mddev->dev_sectors
245 + (PAGE_SIZE/512)))
246 goto bad_alignment;
247 } else if (offset < 0) {
248 /* DATA BITMAP METADATA */
249 if (offset
250 + (long)(page->index * (PAGE_SIZE/512))
251 + size/512 > 0)
252 /* bitmap runs in to metadata */
253 goto bad_alignment;
254 if (rdev->data_offset + mddev->dev_sectors
255 > rdev->sb_start + offset)
256 /* data runs in to bitmap */
257 goto bad_alignment;
258 } else if (rdev->sb_start < rdev->data_offset) {
259 /* METADATA BITMAP DATA */
260 if (rdev->sb_start
261 + offset
262 + page->index*(PAGE_SIZE/512) + size/512
263 > rdev->data_offset)
264 /* bitmap runs in to data */
265 goto bad_alignment;
266 } else {
267 /* DATA METADATA BITMAP - no problems */
268 }
269 md_super_write(mddev, rdev,
270 rdev->sb_start + offset
271 + page->index * (PAGE_SIZE/512),
272 size,
273 page);
274 }
275
276 if (wait && md_super_wait(mddev) < 0)
277 goto restart;
278 return 0;
279
280 bad_alignment:
281 return -EINVAL;
282}
283
284static void md_bitmap_file_kick(struct bitmap *bitmap);
285/*
286 * write out a page to a file
287 */
288static void write_page(struct bitmap *bitmap, struct page *page, int wait)
289{
290 struct buffer_head *bh;
291
292 if (bitmap->storage.file == NULL) {
293 switch (write_sb_page(bitmap, page, wait)) {
294 case -EINVAL:
295 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
296 }
297 } else {
298
299 bh = page_buffers(page);
300
301 while (bh && bh->b_blocknr) {
302 atomic_inc(&bitmap->pending_writes);
303 set_buffer_locked(bh);
304 set_buffer_mapped(bh);
305 submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
306 bh = bh->b_this_page;
307 }
308
309 if (wait)
310 wait_event(bitmap->write_wait,
311 atomic_read(&bitmap->pending_writes)==0);
312 }
313 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
314 md_bitmap_file_kick(bitmap);
315}
316
317static void end_bitmap_write(struct buffer_head *bh, int uptodate)
318{
319 struct bitmap *bitmap = bh->b_private;
320
321 if (!uptodate)
322 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
323 if (atomic_dec_and_test(&bitmap->pending_writes))
324 wake_up(&bitmap->write_wait);
325}
326
327static void free_buffers(struct page *page)
328{
329 struct buffer_head *bh;
330
331 if (!PagePrivate(page))
332 return;
333
334 bh = page_buffers(page);
335 while (bh) {
336 struct buffer_head *next = bh->b_this_page;
337 free_buffer_head(bh);
338 bh = next;
339 }
340 detach_page_private(page);
341 put_page(page);
342}
343
344/* read a page from a file.
345 * We both read the page, and attach buffers to the page to record the
346 * address of each block (using bmap). These addresses will be used
347 * to write the block later, completely bypassing the filesystem.
348 * This usage is similar to how swap files are handled, and allows us
349 * to write to a file with no concerns of memory allocation failing.
350 */
351static int read_page(struct file *file, unsigned long index,
352 struct bitmap *bitmap,
353 unsigned long count,
354 struct page *page)
355{
356 int ret = 0;
357 struct inode *inode = file_inode(file);
358 struct buffer_head *bh;
359 sector_t block, blk_cur;
360
361 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
362 (unsigned long long)index << PAGE_SHIFT);
363
364 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, false);
365 if (!bh) {
366 ret = -ENOMEM;
367 goto out;
368 }
369 attach_page_private(page, bh);
370 blk_cur = index << (PAGE_SHIFT - inode->i_blkbits);
371 while (bh) {
372 block = blk_cur;
373
374 if (count == 0)
375 bh->b_blocknr = 0;
376 else {
377 ret = bmap(inode, &block);
378 if (ret || !block) {
379 ret = -EINVAL;
380 bh->b_blocknr = 0;
381 goto out;
382 }
383
384 bh->b_blocknr = block;
385 bh->b_bdev = inode->i_sb->s_bdev;
386 if (count < (1<<inode->i_blkbits))
387 count = 0;
388 else
389 count -= (1<<inode->i_blkbits);
390
391 bh->b_end_io = end_bitmap_write;
392 bh->b_private = bitmap;
393 atomic_inc(&bitmap->pending_writes);
394 set_buffer_locked(bh);
395 set_buffer_mapped(bh);
396 submit_bh(REQ_OP_READ, 0, bh);
397 }
398 blk_cur++;
399 bh = bh->b_this_page;
400 }
401 page->index = index;
402
403 wait_event(bitmap->write_wait,
404 atomic_read(&bitmap->pending_writes)==0);
405 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
406 ret = -EIO;
407out:
408 if (ret)
409 pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
410 (int)PAGE_SIZE,
411 (unsigned long long)index << PAGE_SHIFT,
412 ret);
413 return ret;
414}
415
416/*
417 * bitmap file superblock operations
418 */
419
420/*
421 * md_bitmap_wait_writes() should be called before writing any bitmap
422 * blocks, to ensure previous writes, particularly from
423 * md_bitmap_daemon_work(), have completed.
424 */
425static void md_bitmap_wait_writes(struct bitmap *bitmap)
426{
427 if (bitmap->storage.file)
428 wait_event(bitmap->write_wait,
429 atomic_read(&bitmap->pending_writes)==0);
430 else
431 /* Note that we ignore the return value. The writes
432 * might have failed, but that would just mean that
433 * some bits which should be cleared haven't been,
434 * which is safe. The relevant bitmap blocks will
435 * probably get written again, but there is no great
436 * loss if they aren't.
437 */
438 md_super_wait(bitmap->mddev);
439}
440
441
442/* update the event counter and sync the superblock to disk */
443void md_bitmap_update_sb(struct bitmap *bitmap)
444{
445 bitmap_super_t *sb;
446
447 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
448 return;
449 if (bitmap->mddev->bitmap_info.external)
450 return;
451 if (!bitmap->storage.sb_page) /* no superblock */
452 return;
453 sb = kmap_atomic(bitmap->storage.sb_page);
454 sb->events = cpu_to_le64(bitmap->mddev->events);
455 if (bitmap->mddev->events < bitmap->events_cleared)
456 /* rocking back to read-only */
457 bitmap->events_cleared = bitmap->mddev->events;
458 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
459 /*
460 * clear BITMAP_WRITE_ERROR bit to protect against the case that
461 * a bitmap write error occurred but the later writes succeeded.
462 */
463 sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR));
464 /* Just in case these have been changed via sysfs: */
465 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
466 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
467 /* This might have been changed by a reshape */
468 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
469 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
470 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
471 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
472 bitmap_info.space);
473 kunmap_atomic(sb);
474 write_page(bitmap, bitmap->storage.sb_page, 1);
475}
476EXPORT_SYMBOL(md_bitmap_update_sb);
477
478/* print out the bitmap file superblock */
479void md_bitmap_print_sb(struct bitmap *bitmap)
480{
481 bitmap_super_t *sb;
482
483 if (!bitmap || !bitmap->storage.sb_page)
484 return;
485 sb = kmap_atomic(bitmap->storage.sb_page);
486 pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
487 pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic));
488 pr_debug(" version: %d\n", le32_to_cpu(sb->version));
489 pr_debug(" uuid: %08x.%08x.%08x.%08x\n",
490 le32_to_cpu(*(__le32 *)(sb->uuid+0)),
491 le32_to_cpu(*(__le32 *)(sb->uuid+4)),
492 le32_to_cpu(*(__le32 *)(sb->uuid+8)),
493 le32_to_cpu(*(__le32 *)(sb->uuid+12)));
494 pr_debug(" events: %llu\n",
495 (unsigned long long) le64_to_cpu(sb->events));
496 pr_debug("events cleared: %llu\n",
497 (unsigned long long) le64_to_cpu(sb->events_cleared));
498 pr_debug(" state: %08x\n", le32_to_cpu(sb->state));
499 pr_debug(" chunksize: %d B\n", le32_to_cpu(sb->chunksize));
500 pr_debug(" daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
501 pr_debug(" sync size: %llu KB\n",
502 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
503 pr_debug("max write behind: %d\n", le32_to_cpu(sb->write_behind));
504 kunmap_atomic(sb);
505}
506
507/*
508 * bitmap_new_disk_sb
509 * @bitmap
510 *
511 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
512 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
513 * This function verifies 'bitmap_info' and populates the on-disk bitmap
514 * structure, which is to be written to disk.
515 *
516 * Returns: 0 on success, -Exxx on error
517 */
518static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
519{
520 bitmap_super_t *sb;
521 unsigned long chunksize, daemon_sleep, write_behind;
522
523 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
524 if (bitmap->storage.sb_page == NULL)
525 return -ENOMEM;
526 bitmap->storage.sb_page->index = 0;
527
528 sb = kmap_atomic(bitmap->storage.sb_page);
529
530 sb->magic = cpu_to_le32(BITMAP_MAGIC);
531 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
532
533 chunksize = bitmap->mddev->bitmap_info.chunksize;
534 BUG_ON(!chunksize);
535 if (!is_power_of_2(chunksize)) {
536 kunmap_atomic(sb);
537 pr_warn("bitmap chunksize not a power of 2\n");
538 return -EINVAL;
539 }
540 sb->chunksize = cpu_to_le32(chunksize);
541
542 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
543 if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
544 pr_debug("Choosing daemon_sleep default (5 sec)\n");
545 daemon_sleep = 5 * HZ;
546 }
547 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
548 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
549
550 /*
551 * FIXME: write_behind for RAID1. If not specified, what
552 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
553 */
554 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
555 if (write_behind > COUNTER_MAX)
556 write_behind = COUNTER_MAX / 2;
557 sb->write_behind = cpu_to_le32(write_behind);
558 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
559
560 /* keep the array size field of the bitmap superblock up to date */
561 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
562
563 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
564
565 set_bit(BITMAP_STALE, &bitmap->flags);
566 sb->state = cpu_to_le32(bitmap->flags);
567 bitmap->events_cleared = bitmap->mddev->events;
568 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
569 bitmap->mddev->bitmap_info.nodes = 0;
570
571 kunmap_atomic(sb);
572
573 return 0;
574}
575
576/* read the superblock from the bitmap file and initialize some bitmap fields */
577static int md_bitmap_read_sb(struct bitmap *bitmap)
578{
579 char *reason = NULL;
580 bitmap_super_t *sb;
581 unsigned long chunksize, daemon_sleep, write_behind;
582 unsigned long long events;
583 int nodes = 0;
584 unsigned long sectors_reserved = 0;
585 int err = -EINVAL;
586 struct page *sb_page;
587 loff_t offset = bitmap->mddev->bitmap_info.offset;
588
589 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
590 chunksize = 128 * 1024 * 1024;
591 daemon_sleep = 5 * HZ;
592 write_behind = 0;
593 set_bit(BITMAP_STALE, &bitmap->flags);
594 err = 0;
595 goto out_no_sb;
596 }
597 /* page 0 is the superblock, read it... */
598 sb_page = alloc_page(GFP_KERNEL);
599 if (!sb_page)
600 return -ENOMEM;
601 bitmap->storage.sb_page = sb_page;
602
603re_read:
604 /* If cluster_slot is set, the cluster is setup */
605 if (bitmap->cluster_slot >= 0) {
606 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
607
608 sector_div(bm_blocks,
609 bitmap->mddev->bitmap_info.chunksize >> 9);
610 /* bits to bytes */
611 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
612 /* to 4k blocks */
613 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
614 offset = bitmap->mddev->bitmap_info.offset + (bitmap->cluster_slot * (bm_blocks << 3));
615 pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
616 bitmap->cluster_slot, offset);
617 }
618
619 if (bitmap->storage.file) {
620 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
621 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
622
623 err = read_page(bitmap->storage.file, 0,
624 bitmap, bytes, sb_page);
625 } else {
626 err = read_sb_page(bitmap->mddev,
627 offset,
628 sb_page,
629 0, sizeof(bitmap_super_t));
630 }
631 if (err)
632 return err;
633
634 err = -EINVAL;
635 sb = kmap_atomic(sb_page);
636
637 chunksize = le32_to_cpu(sb->chunksize);
638 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
639 write_behind = le32_to_cpu(sb->write_behind);
640 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
641 /* Setup nodes/clustername only if bitmap version is
642 * cluster-compatible
643 */
644 if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
645 nodes = le32_to_cpu(sb->nodes);
646 strlcpy(bitmap->mddev->bitmap_info.cluster_name,
647 sb->cluster_name, 64);
648 }
649
650 /* verify that the bitmap-specific fields are valid */
651 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
652 reason = "bad magic";
653 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
654 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
655 reason = "unrecognized superblock version";
656 else if (chunksize < 512)
657 reason = "bitmap chunksize too small";
658 else if (!is_power_of_2(chunksize))
659 reason = "bitmap chunksize not a power of 2";
660 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
661 reason = "daemon sleep period out of range";
662 else if (write_behind > COUNTER_MAX)
663 reason = "write-behind limit out of range (0 - 16383)";
664 if (reason) {
665 pr_warn("%s: invalid bitmap file superblock: %s\n",
666 bmname(bitmap), reason);
667 goto out;
668 }
669
670 /* keep the array size field of the bitmap superblock up to date */
671 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
672
673 if (bitmap->mddev->persistent) {
674 /*
675 * We have a persistent array superblock, so compare the
676 * bitmap's UUID and event counter to the mddev's
677 */
678 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
679 pr_warn("%s: bitmap superblock UUID mismatch\n",
680 bmname(bitmap));
681 goto out;
682 }
683 events = le64_to_cpu(sb->events);
684 if (!nodes && (events < bitmap->mddev->events)) {
685 pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
686 bmname(bitmap), events,
687 (unsigned long long) bitmap->mddev->events);
688 set_bit(BITMAP_STALE, &bitmap->flags);
689 }
690 }
691
692 /* assign fields using values from superblock */
693 bitmap->flags |= le32_to_cpu(sb->state);
694 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
695 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
696 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
697 strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
698 err = 0;
699
700out:
701 kunmap_atomic(sb);
702 /* Assigning chunksize is required for "re_read" */
703 bitmap->mddev->bitmap_info.chunksize = chunksize;
704 if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
705 err = md_setup_cluster(bitmap->mddev, nodes);
706 if (err) {
707 pr_warn("%s: Could not setup cluster service (%d)\n",
708 bmname(bitmap), err);
709 goto out_no_sb;
710 }
711 bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
712 goto re_read;
713 }
714
715
716out_no_sb:
717 if (test_bit(BITMAP_STALE, &bitmap->flags))
718 bitmap->events_cleared = bitmap->mddev->events;
719 bitmap->mddev->bitmap_info.chunksize = chunksize;
720 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
721 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
722 bitmap->mddev->bitmap_info.nodes = nodes;
723 if (bitmap->mddev->bitmap_info.space == 0 ||
724 bitmap->mddev->bitmap_info.space > sectors_reserved)
725 bitmap->mddev->bitmap_info.space = sectors_reserved;
726 if (err) {
727 md_bitmap_print_sb(bitmap);
728 if (bitmap->cluster_slot < 0)
729 md_cluster_stop(bitmap->mddev);
730 }
731 return err;
732}
733
734/*
735 * general bitmap file operations
736 */
737
738/*
739 * on-disk bitmap:
740 *
741 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
742 * file a page at a time. There's a superblock at the start of the file.
743 */
744/* calculate the index of the page that contains this bit */
745static inline unsigned long file_page_index(struct bitmap_storage *store,
746 unsigned long chunk)
747{
748 if (store->sb_page)
749 chunk += sizeof(bitmap_super_t) << 3;
750 return chunk >> PAGE_BIT_SHIFT;
751}
752
753/* calculate the (bit) offset of this bit within a page */
754static inline unsigned long file_page_offset(struct bitmap_storage *store,
755 unsigned long chunk)
756{
757 if (store->sb_page)
758 chunk += sizeof(bitmap_super_t) << 3;
759 return chunk & (PAGE_BITS - 1);
760}
761
762/*
763 * return a pointer to the page in the filemap that contains the given bit
764 *
765 */
766static inline struct page *filemap_get_page(struct bitmap_storage *store,
767 unsigned long chunk)
768{
769 if (file_page_index(store, chunk) >= store->file_pages)
770 return NULL;
771 return store->filemap[file_page_index(store, chunk)];
772}
773
774static int md_bitmap_storage_alloc(struct bitmap_storage *store,
775 unsigned long chunks, int with_super,
776 int slot_number)
777{
778 int pnum, offset = 0;
779 unsigned long num_pages;
780 unsigned long bytes;
781
782 bytes = DIV_ROUND_UP(chunks, 8);
783 if (with_super)
784 bytes += sizeof(bitmap_super_t);
785
786 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
787 offset = slot_number * num_pages;
788
789 store->filemap = kmalloc_array(num_pages, sizeof(struct page *),
790 GFP_KERNEL);
791 if (!store->filemap)
792 return -ENOMEM;
793
794 if (with_super && !store->sb_page) {
795 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
796 if (store->sb_page == NULL)
797 return -ENOMEM;
798 }
799
800 pnum = 0;
801 if (store->sb_page) {
802 store->filemap[0] = store->sb_page;
803 pnum = 1;
804 store->sb_page->index = offset;
805 }
806
807 for ( ; pnum < num_pages; pnum++) {
808 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
809 if (!store->filemap[pnum]) {
810 store->file_pages = pnum;
811 return -ENOMEM;
812 }
813 store->filemap[pnum]->index = pnum + offset;
814 }
815 store->file_pages = pnum;
816
817 /* We need 4 bits per page, rounded up to a multiple
818 * of sizeof(unsigned long) */
819 store->filemap_attr = kzalloc(
820 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
821 GFP_KERNEL);
822 if (!store->filemap_attr)
823 return -ENOMEM;
824
825 store->bytes = bytes;
826
827 return 0;
828}
829
830static void md_bitmap_file_unmap(struct bitmap_storage *store)
831{
832 struct page **map, *sb_page;
833 int pages;
834 struct file *file;
835
836 file = store->file;
837 map = store->filemap;
838 pages = store->file_pages;
839 sb_page = store->sb_page;
840
841 while (pages--)
842 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
843 free_buffers(map[pages]);
844 kfree(map);
845 kfree(store->filemap_attr);
846
847 if (sb_page)
848 free_buffers(sb_page);
849
850 if (file) {
851 struct inode *inode = file_inode(file);
852 invalidate_mapping_pages(inode->i_mapping, 0, -1);
853 fput(file);
854 }
855}
856
857/*
858 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
859 * then it is no longer reliable, so we stop using it and we mark the file
860 * as failed in the superblock
861 */
862static void md_bitmap_file_kick(struct bitmap *bitmap)
863{
864 char *path, *ptr = NULL;
865
866 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
867 md_bitmap_update_sb(bitmap);
868
869 if (bitmap->storage.file) {
870 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
871 if (path)
872 ptr = file_path(bitmap->storage.file,
873 path, PAGE_SIZE);
874
875 pr_warn("%s: kicking failed bitmap file %s from array!\n",
876 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
877
878 kfree(path);
879 } else
880 pr_warn("%s: disabling internal bitmap due to errors\n",
881 bmname(bitmap));
882 }
883}
884
885enum bitmap_page_attr {
886 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
887 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
888 * i.e. counter is 1 or 2. */
889 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
890};
891
892static inline void set_page_attr(struct bitmap *bitmap, int pnum,
893 enum bitmap_page_attr attr)
894{
895 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
896}
897
898static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
899 enum bitmap_page_attr attr)
900{
901 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
902}
903
904static inline int test_page_attr(struct bitmap *bitmap, int pnum,
905 enum bitmap_page_attr attr)
906{
907 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
908}
909
910static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
911 enum bitmap_page_attr attr)
912{
913 return test_and_clear_bit((pnum<<2) + attr,
914 bitmap->storage.filemap_attr);
915}
916/*
917 * bitmap_file_set_bit -- called before performing a write to the md device
918 * to set (and eventually sync) a particular bit in the bitmap file
919 *
920 * we set the bit immediately, then we record the page number so that
921 * when an unplug occurs, we can flush the dirty pages out to disk
922 */
923static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
924{
925 unsigned long bit;
926 struct page *page;
927 void *kaddr;
928 unsigned long chunk = block >> bitmap->counts.chunkshift;
929 struct bitmap_storage *store = &bitmap->storage;
930 unsigned long node_offset = 0;
931
932 if (mddev_is_clustered(bitmap->mddev))
933 node_offset = bitmap->cluster_slot * store->file_pages;
934
935 page = filemap_get_page(&bitmap->storage, chunk);
936 if (!page)
937 return;
938 bit = file_page_offset(&bitmap->storage, chunk);
939
940 /* set the bit */
941 kaddr = kmap_atomic(page);
942 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
943 set_bit(bit, kaddr);
944 else
945 set_bit_le(bit, kaddr);
946 kunmap_atomic(kaddr);
947 pr_debug("set file bit %lu page %lu\n", bit, page->index);
948 /* record page number so it gets flushed to disk when unplug occurs */
949 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_DIRTY);
950}
951
952static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
953{
954 unsigned long bit;
955 struct page *page;
956 void *paddr;
957 unsigned long chunk = block >> bitmap->counts.chunkshift;
958 struct bitmap_storage *store = &bitmap->storage;
959 unsigned long node_offset = 0;
960
961 if (mddev_is_clustered(bitmap->mddev))
962 node_offset = bitmap->cluster_slot * store->file_pages;
963
964 page = filemap_get_page(&bitmap->storage, chunk);
965 if (!page)
966 return;
967 bit = file_page_offset(&bitmap->storage, chunk);
968 paddr = kmap_atomic(page);
969 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
970 clear_bit(bit, paddr);
971 else
972 clear_bit_le(bit, paddr);
973 kunmap_atomic(paddr);
974 if (!test_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
975 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_PENDING);
976 bitmap->allclean = 0;
977 }
978}
979
980static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
981{
982 unsigned long bit;
983 struct page *page;
984 void *paddr;
985 unsigned long chunk = block >> bitmap->counts.chunkshift;
986 int set = 0;
987
988 page = filemap_get_page(&bitmap->storage, chunk);
989 if (!page)
990 return -EINVAL;
991 bit = file_page_offset(&bitmap->storage, chunk);
992 paddr = kmap_atomic(page);
993 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
994 set = test_bit(bit, paddr);
995 else
996 set = test_bit_le(bit, paddr);
997 kunmap_atomic(paddr);
998 return set;
999}
1000
1001
1002/* this gets called when the md device is ready to unplug its underlying
1003 * (slave) device queues -- before we let any writes go down, we need to
1004 * sync the dirty pages of the bitmap file to disk */
1005void md_bitmap_unplug(struct bitmap *bitmap)
1006{
1007 unsigned long i;
1008 int dirty, need_write;
1009 int writing = 0;
1010
1011 if (!bitmap || !bitmap->storage.filemap ||
1012 test_bit(BITMAP_STALE, &bitmap->flags))
1013 return;
1014
1015 /* look at each page to see if there are any set bits that need to be
1016 * flushed out to disk */
1017 for (i = 0; i < bitmap->storage.file_pages; i++) {
1018 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1019 need_write = test_and_clear_page_attr(bitmap, i,
1020 BITMAP_PAGE_NEEDWRITE);
1021 if (dirty || need_write) {
1022 if (!writing) {
1023 md_bitmap_wait_writes(bitmap);
1024 if (bitmap->mddev->queue)
1025 blk_add_trace_msg(bitmap->mddev->queue,
1026 "md bitmap_unplug");
1027 }
1028 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
1029 write_page(bitmap, bitmap->storage.filemap[i], 0);
1030 writing = 1;
1031 }
1032 }
1033 if (writing)
1034 md_bitmap_wait_writes(bitmap);
1035
1036 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1037 md_bitmap_file_kick(bitmap);
1038}
1039EXPORT_SYMBOL(md_bitmap_unplug);
1040
1041static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1042/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
1043 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
1044 * memory mapping of the bitmap file
1045 * Special cases:
1046 * if there's no bitmap file, or if the bitmap file had been
1047 * previously kicked from the array, we mark all the bits as
1048 * 1's in order to cause a full resync.
1049 *
1050 * We ignore all bits for sectors that end earlier than 'start'.
1051 * This is used when reading an out-of-date bitmap...
1052 */
1053static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1054{
1055 unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
1056 struct page *page = NULL;
1057 unsigned long bit_cnt = 0;
1058 struct file *file;
1059 unsigned long offset;
1060 int outofdate;
1061 int ret = -ENOSPC;
1062 void *paddr;
1063 struct bitmap_storage *store = &bitmap->storage;
1064
1065 chunks = bitmap->counts.chunks;
1066 file = store->file;
1067
1068 if (!file && !bitmap->mddev->bitmap_info.offset) {
1069 /* No permanent bitmap - fill with '1s'. */
1070 store->filemap = NULL;
1071 store->file_pages = 0;
1072 for (i = 0; i < chunks ; i++) {
1073 /* if the disk bit is set, set the memory bit */
1074 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1075 >= start);
1076 md_bitmap_set_memory_bits(bitmap,
1077 (sector_t)i << bitmap->counts.chunkshift,
1078 needed);
1079 }
1080 return 0;
1081 }
1082
1083 outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1084 if (outofdate)
1085 pr_warn("%s: bitmap file is out of date, doing full recovery\n", bmname(bitmap));
1086
1087 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
1088 pr_warn("%s: bitmap file too short %lu < %lu\n",
1089 bmname(bitmap),
1090 (unsigned long) i_size_read(file->f_mapping->host),
1091 store->bytes);
1092 goto err;
1093 }
1094
1095 oldindex = ~0L;
1096 offset = 0;
1097 if (!bitmap->mddev->bitmap_info.external)
1098 offset = sizeof(bitmap_super_t);
1099
1100 if (mddev_is_clustered(bitmap->mddev))
1101 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1102
1103 for (i = 0; i < chunks; i++) {
1104 int b;
1105 index = file_page_index(&bitmap->storage, i);
1106 bit = file_page_offset(&bitmap->storage, i);
1107 if (index != oldindex) { /* this is a new page, read it in */
1108 int count;
1109 /* unmap the old page, we're done with it */
1110 if (index == store->file_pages-1)
1111 count = store->bytes - index * PAGE_SIZE;
1112 else
1113 count = PAGE_SIZE;
1114 page = store->filemap[index];
1115 if (file)
1116 ret = read_page(file, index, bitmap,
1117 count, page);
1118 else
1119 ret = read_sb_page(
1120 bitmap->mddev,
1121 bitmap->mddev->bitmap_info.offset,
1122 page,
1123 index + node_offset, count);
1124
1125 if (ret)
1126 goto err;
1127
1128 oldindex = index;
1129
1130 if (outofdate) {
1131 /*
1132 * if bitmap is out of date, dirty the
1133 * whole page and write it out
1134 */
1135 paddr = kmap_atomic(page);
1136 memset(paddr + offset, 0xff,
1137 PAGE_SIZE - offset);
1138 kunmap_atomic(paddr);
1139 write_page(bitmap, page, 1);
1140
1141 ret = -EIO;
1142 if (test_bit(BITMAP_WRITE_ERROR,
1143 &bitmap->flags))
1144 goto err;
1145 }
1146 }
1147 paddr = kmap_atomic(page);
1148 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1149 b = test_bit(bit, paddr);
1150 else
1151 b = test_bit_le(bit, paddr);
1152 kunmap_atomic(paddr);
1153 if (b) {
1154 /* if the disk bit is set, set the memory bit */
1155 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1156 >= start);
1157 md_bitmap_set_memory_bits(bitmap,
1158 (sector_t)i << bitmap->counts.chunkshift,
1159 needed);
1160 bit_cnt++;
1161 }
1162 offset = 0;
1163 }
1164
1165 pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
1166 bmname(bitmap), store->file_pages,
1167 bit_cnt, chunks);
1168
1169 return 0;
1170
1171 err:
1172 pr_warn("%s: bitmap initialisation failed: %d\n",
1173 bmname(bitmap), ret);
1174 return ret;
1175}
1176
1177void md_bitmap_write_all(struct bitmap *bitmap)
1178{
1179 /* We don't actually write all bitmap blocks here,
1180 * just flag them as needing to be written
1181 */
1182 int i;
1183
1184 if (!bitmap || !bitmap->storage.filemap)
1185 return;
1186 if (bitmap->storage.file)
1187 /* Only one copy, so nothing needed */
1188 return;
1189
1190 for (i = 0; i < bitmap->storage.file_pages; i++)
1191 set_page_attr(bitmap, i,
1192 BITMAP_PAGE_NEEDWRITE);
1193 bitmap->allclean = 0;
1194}
1195
1196static void md_bitmap_count_page(struct bitmap_counts *bitmap,
1197 sector_t offset, int inc)
1198{
1199 sector_t chunk = offset >> bitmap->chunkshift;
1200 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1201 bitmap->bp[page].count += inc;
1202 md_bitmap_checkfree(bitmap, page);
1203}
1204
1205static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1206{
1207 sector_t chunk = offset >> bitmap->chunkshift;
1208 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1209 struct bitmap_page *bp = &bitmap->bp[page];
1210
1211 if (!bp->pending)
1212 bp->pending = 1;
1213}
1214
1215static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1216 sector_t offset, sector_t *blocks,
1217 int create);
1218
1219/*
1220 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1221 * out to disk
1222 */
1223
1224void md_bitmap_daemon_work(struct mddev *mddev)
1225{
1226 struct bitmap *bitmap;
1227 unsigned long j;
1228 unsigned long nextpage;
1229 sector_t blocks;
1230 struct bitmap_counts *counts;
1231
1232 /* Use a mutex to guard daemon_work against
1233 * bitmap_destroy.
1234 */
1235 mutex_lock(&mddev->bitmap_info.mutex);
1236 bitmap = mddev->bitmap;
1237 if (bitmap == NULL) {
1238 mutex_unlock(&mddev->bitmap_info.mutex);
1239 return;
1240 }
1241 if (time_before(jiffies, bitmap->daemon_lastrun
1242 + mddev->bitmap_info.daemon_sleep))
1243 goto done;
1244
1245 bitmap->daemon_lastrun = jiffies;
1246 if (bitmap->allclean) {
1247 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1248 goto done;
1249 }
1250 bitmap->allclean = 1;
1251
1252 if (bitmap->mddev->queue)
1253 blk_add_trace_msg(bitmap->mddev->queue,
1254 "md bitmap_daemon_work");
1255
1256 /* Any file-page which is PENDING now needs to be written.
1257 * So set NEEDWRITE now, then after we make any last-minute changes
1258 * we will write it.
1259 */
1260 for (j = 0; j < bitmap->storage.file_pages; j++)
1261 if (test_and_clear_page_attr(bitmap, j,
1262 BITMAP_PAGE_PENDING))
1263 set_page_attr(bitmap, j,
1264 BITMAP_PAGE_NEEDWRITE);
1265
1266 if (bitmap->need_sync &&
1267 mddev->bitmap_info.external == 0) {
1268 /* Arrange for superblock update as well as
1269 * other changes */
1270 bitmap_super_t *sb;
1271 bitmap->need_sync = 0;
1272 if (bitmap->storage.filemap) {
1273 sb = kmap_atomic(bitmap->storage.sb_page);
1274 sb->events_cleared =
1275 cpu_to_le64(bitmap->events_cleared);
1276 kunmap_atomic(sb);
1277 set_page_attr(bitmap, 0,
1278 BITMAP_PAGE_NEEDWRITE);
1279 }
1280 }
1281 /* Now look at the bitmap counters and if any are '2' or '1',
1282 * decrement and handle accordingly.
1283 */
1284 counts = &bitmap->counts;
1285 spin_lock_irq(&counts->lock);
1286 nextpage = 0;
1287 for (j = 0; j < counts->chunks; j++) {
1288 bitmap_counter_t *bmc;
1289 sector_t block = (sector_t)j << counts->chunkshift;
1290
1291 if (j == nextpage) {
1292 nextpage += PAGE_COUNTER_RATIO;
1293 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1294 j |= PAGE_COUNTER_MASK;
1295 continue;
1296 }
1297 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1298 }
1299
1300 bmc = md_bitmap_get_counter(counts, block, &blocks, 0);
1301 if (!bmc) {
1302 j |= PAGE_COUNTER_MASK;
1303 continue;
1304 }
1305 if (*bmc == 1 && !bitmap->need_sync) {
1306 /* We can clear the bit */
1307 *bmc = 0;
1308 md_bitmap_count_page(counts, block, -1);
1309 md_bitmap_file_clear_bit(bitmap, block);
1310 } else if (*bmc && *bmc <= 2) {
1311 *bmc = 1;
1312 md_bitmap_set_pending(counts, block);
1313 bitmap->allclean = 0;
1314 }
1315 }
1316 spin_unlock_irq(&counts->lock);
1317
1318 md_bitmap_wait_writes(bitmap);
1319 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1320 * DIRTY pages need to be written by bitmap_unplug so it can wait
1321 * for them.
1322 * If we find any DIRTY page we stop there and let bitmap_unplug
1323 * handle all the rest. This is important in the case where
1324 * the first blocking holds the superblock and it has been updated.
1325 * We mustn't write any other blocks before the superblock.
1326 */
1327 for (j = 0;
1328 j < bitmap->storage.file_pages
1329 && !test_bit(BITMAP_STALE, &bitmap->flags);
1330 j++) {
1331 if (test_page_attr(bitmap, j,
1332 BITMAP_PAGE_DIRTY))
1333 /* bitmap_unplug will handle the rest */
1334 break;
1335 if (bitmap->storage.filemap &&
1336 test_and_clear_page_attr(bitmap, j,
1337 BITMAP_PAGE_NEEDWRITE)) {
1338 write_page(bitmap, bitmap->storage.filemap[j], 0);
1339 }
1340 }
1341
1342 done:
1343 if (bitmap->allclean == 0)
1344 mddev->thread->timeout =
1345 mddev->bitmap_info.daemon_sleep;
1346 mutex_unlock(&mddev->bitmap_info.mutex);
1347}
1348
1349static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1350 sector_t offset, sector_t *blocks,
1351 int create)
1352__releases(bitmap->lock)
1353__acquires(bitmap->lock)
1354{
1355 /* If 'create', we might release the lock and reclaim it.
1356 * The lock must have been taken with interrupts enabled.
1357 * If !create, we don't release the lock.
1358 */
1359 sector_t chunk = offset >> bitmap->chunkshift;
1360 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1361 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1362 sector_t csize;
1363 int err;
1364
1365 err = md_bitmap_checkpage(bitmap, page, create, 0);
1366
1367 if (bitmap->bp[page].hijacked ||
1368 bitmap->bp[page].map == NULL)
1369 csize = ((sector_t)1) << (bitmap->chunkshift +
1370 PAGE_COUNTER_SHIFT - 1);
1371 else
1372 csize = ((sector_t)1) << bitmap->chunkshift;
1373 *blocks = csize - (offset & (csize - 1));
1374
1375 if (err < 0)
1376 return NULL;
1377
1378 /* now locked ... */
1379
1380 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1381 /* should we use the first or second counter field
1382 * of the hijacked pointer? */
1383 int hi = (pageoff > PAGE_COUNTER_MASK);
1384 return &((bitmap_counter_t *)
1385 &bitmap->bp[page].map)[hi];
1386 } else /* page is allocated */
1387 return (bitmap_counter_t *)
1388 &(bitmap->bp[page].map[pageoff]);
1389}
1390
1391int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1392{
1393 if (!bitmap)
1394 return 0;
1395
1396 if (behind) {
1397 int bw;
1398 atomic_inc(&bitmap->behind_writes);
1399 bw = atomic_read(&bitmap->behind_writes);
1400 if (bw > bitmap->behind_writes_used)
1401 bitmap->behind_writes_used = bw;
1402
1403 pr_debug("inc write-behind count %d/%lu\n",
1404 bw, bitmap->mddev->bitmap_info.max_write_behind);
1405 }
1406
1407 while (sectors) {
1408 sector_t blocks;
1409 bitmap_counter_t *bmc;
1410
1411 spin_lock_irq(&bitmap->counts.lock);
1412 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1413 if (!bmc) {
1414 spin_unlock_irq(&bitmap->counts.lock);
1415 return 0;
1416 }
1417
1418 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1419 DEFINE_WAIT(__wait);
1420 /* note that it is safe to do the prepare_to_wait
1421 * after the test as long as we do it before dropping
1422 * the spinlock.
1423 */
1424 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1425 TASK_UNINTERRUPTIBLE);
1426 spin_unlock_irq(&bitmap->counts.lock);
1427 schedule();
1428 finish_wait(&bitmap->overflow_wait, &__wait);
1429 continue;
1430 }
1431
1432 switch (*bmc) {
1433 case 0:
1434 md_bitmap_file_set_bit(bitmap, offset);
1435 md_bitmap_count_page(&bitmap->counts, offset, 1);
1436 fallthrough;
1437 case 1:
1438 *bmc = 2;
1439 }
1440
1441 (*bmc)++;
1442
1443 spin_unlock_irq(&bitmap->counts.lock);
1444
1445 offset += blocks;
1446 if (sectors > blocks)
1447 sectors -= blocks;
1448 else
1449 sectors = 0;
1450 }
1451 return 0;
1452}
1453EXPORT_SYMBOL(md_bitmap_startwrite);
1454
1455void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
1456 unsigned long sectors, int success, int behind)
1457{
1458 if (!bitmap)
1459 return;
1460 if (behind) {
1461 if (atomic_dec_and_test(&bitmap->behind_writes))
1462 wake_up(&bitmap->behind_wait);
1463 pr_debug("dec write-behind count %d/%lu\n",
1464 atomic_read(&bitmap->behind_writes),
1465 bitmap->mddev->bitmap_info.max_write_behind);
1466 }
1467
1468 while (sectors) {
1469 sector_t blocks;
1470 unsigned long flags;
1471 bitmap_counter_t *bmc;
1472
1473 spin_lock_irqsave(&bitmap->counts.lock, flags);
1474 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1475 if (!bmc) {
1476 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1477 return;
1478 }
1479
1480 if (success && !bitmap->mddev->degraded &&
1481 bitmap->events_cleared < bitmap->mddev->events) {
1482 bitmap->events_cleared = bitmap->mddev->events;
1483 bitmap->need_sync = 1;
1484 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1485 }
1486
1487 if (!success && !NEEDED(*bmc))
1488 *bmc |= NEEDED_MASK;
1489
1490 if (COUNTER(*bmc) == COUNTER_MAX)
1491 wake_up(&bitmap->overflow_wait);
1492
1493 (*bmc)--;
1494 if (*bmc <= 2) {
1495 md_bitmap_set_pending(&bitmap->counts, offset);
1496 bitmap->allclean = 0;
1497 }
1498 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1499 offset += blocks;
1500 if (sectors > blocks)
1501 sectors -= blocks;
1502 else
1503 sectors = 0;
1504 }
1505}
1506EXPORT_SYMBOL(md_bitmap_endwrite);
1507
1508static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1509 int degraded)
1510{
1511 bitmap_counter_t *bmc;
1512 int rv;
1513 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1514 *blocks = 1024;
1515 return 1; /* always resync if no bitmap */
1516 }
1517 spin_lock_irq(&bitmap->counts.lock);
1518 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1519 rv = 0;
1520 if (bmc) {
1521 /* locked */
1522 if (RESYNC(*bmc))
1523 rv = 1;
1524 else if (NEEDED(*bmc)) {
1525 rv = 1;
1526 if (!degraded) { /* don't set/clear bits if degraded */
1527 *bmc |= RESYNC_MASK;
1528 *bmc &= ~NEEDED_MASK;
1529 }
1530 }
1531 }
1532 spin_unlock_irq(&bitmap->counts.lock);
1533 return rv;
1534}
1535
1536int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1537 int degraded)
1538{
1539 /* bitmap_start_sync must always report on multiples of whole
1540 * pages, otherwise resync (which is very PAGE_SIZE based) will
1541 * get confused.
1542 * So call __bitmap_start_sync repeatedly (if needed) until
1543 * At least PAGE_SIZE>>9 blocks are covered.
1544 * Return the 'or' of the result.
1545 */
1546 int rv = 0;
1547 sector_t blocks1;
1548
1549 *blocks = 0;
1550 while (*blocks < (PAGE_SIZE>>9)) {
1551 rv |= __bitmap_start_sync(bitmap, offset,
1552 &blocks1, degraded);
1553 offset += blocks1;
1554 *blocks += blocks1;
1555 }
1556 return rv;
1557}
1558EXPORT_SYMBOL(md_bitmap_start_sync);
1559
1560void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1561{
1562 bitmap_counter_t *bmc;
1563 unsigned long flags;
1564
1565 if (bitmap == NULL) {
1566 *blocks = 1024;
1567 return;
1568 }
1569 spin_lock_irqsave(&bitmap->counts.lock, flags);
1570 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1571 if (bmc == NULL)
1572 goto unlock;
1573 /* locked */
1574 if (RESYNC(*bmc)) {
1575 *bmc &= ~RESYNC_MASK;
1576
1577 if (!NEEDED(*bmc) && aborted)
1578 *bmc |= NEEDED_MASK;
1579 else {
1580 if (*bmc <= 2) {
1581 md_bitmap_set_pending(&bitmap->counts, offset);
1582 bitmap->allclean = 0;
1583 }
1584 }
1585 }
1586 unlock:
1587 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1588}
1589EXPORT_SYMBOL(md_bitmap_end_sync);
1590
1591void md_bitmap_close_sync(struct bitmap *bitmap)
1592{
1593 /* Sync has finished, and any bitmap chunks that weren't synced
1594 * properly have been aborted. It remains to us to clear the
1595 * RESYNC bit wherever it is still on
1596 */
1597 sector_t sector = 0;
1598 sector_t blocks;
1599 if (!bitmap)
1600 return;
1601 while (sector < bitmap->mddev->resync_max_sectors) {
1602 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1603 sector += blocks;
1604 }
1605}
1606EXPORT_SYMBOL(md_bitmap_close_sync);
1607
1608void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
1609{
1610 sector_t s = 0;
1611 sector_t blocks;
1612
1613 if (!bitmap)
1614 return;
1615 if (sector == 0) {
1616 bitmap->last_end_sync = jiffies;
1617 return;
1618 }
1619 if (!force && time_before(jiffies, (bitmap->last_end_sync
1620 + bitmap->mddev->bitmap_info.daemon_sleep)))
1621 return;
1622 wait_event(bitmap->mddev->recovery_wait,
1623 atomic_read(&bitmap->mddev->recovery_active) == 0);
1624
1625 bitmap->mddev->curr_resync_completed = sector;
1626 set_bit(MD_SB_CHANGE_CLEAN, &bitmap->mddev->sb_flags);
1627 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1628 s = 0;
1629 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1630 md_bitmap_end_sync(bitmap, s, &blocks, 0);
1631 s += blocks;
1632 }
1633 bitmap->last_end_sync = jiffies;
1634 sysfs_notify_dirent_safe(bitmap->mddev->sysfs_completed);
1635}
1636EXPORT_SYMBOL(md_bitmap_cond_end_sync);
1637
1638void md_bitmap_sync_with_cluster(struct mddev *mddev,
1639 sector_t old_lo, sector_t old_hi,
1640 sector_t new_lo, sector_t new_hi)
1641{
1642 struct bitmap *bitmap = mddev->bitmap;
1643 sector_t sector, blocks = 0;
1644
1645 for (sector = old_lo; sector < new_lo; ) {
1646 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1647 sector += blocks;
1648 }
1649 WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
1650
1651 for (sector = old_hi; sector < new_hi; ) {
1652 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1653 sector += blocks;
1654 }
1655 WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
1656}
1657EXPORT_SYMBOL(md_bitmap_sync_with_cluster);
1658
1659static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1660{
1661 /* For each chunk covered by any of these sectors, set the
1662 * counter to 2 and possibly set resync_needed. They should all
1663 * be 0 at this point
1664 */
1665
1666 sector_t secs;
1667 bitmap_counter_t *bmc;
1668 spin_lock_irq(&bitmap->counts.lock);
1669 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1670 if (!bmc) {
1671 spin_unlock_irq(&bitmap->counts.lock);
1672 return;
1673 }
1674 if (!*bmc) {
1675 *bmc = 2;
1676 md_bitmap_count_page(&bitmap->counts, offset, 1);
1677 md_bitmap_set_pending(&bitmap->counts, offset);
1678 bitmap->allclean = 0;
1679 }
1680 if (needed)
1681 *bmc |= NEEDED_MASK;
1682 spin_unlock_irq(&bitmap->counts.lock);
1683}
1684
1685/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1686void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1687{
1688 unsigned long chunk;
1689
1690 for (chunk = s; chunk <= e; chunk++) {
1691 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1692 md_bitmap_set_memory_bits(bitmap, sec, 1);
1693 md_bitmap_file_set_bit(bitmap, sec);
1694 if (sec < bitmap->mddev->recovery_cp)
1695 /* We are asserting that the array is dirty,
1696 * so move the recovery_cp address back so
1697 * that it is obvious that it is dirty
1698 */
1699 bitmap->mddev->recovery_cp = sec;
1700 }
1701}
1702
1703/*
1704 * flush out any pending updates
1705 */
1706void md_bitmap_flush(struct mddev *mddev)
1707{
1708 struct bitmap *bitmap = mddev->bitmap;
1709 long sleep;
1710
1711 if (!bitmap) /* there was no bitmap */
1712 return;
1713
1714 /* run the daemon_work three time to ensure everything is flushed
1715 * that can be
1716 */
1717 sleep = mddev->bitmap_info.daemon_sleep * 2;
1718 bitmap->daemon_lastrun -= sleep;
1719 md_bitmap_daemon_work(mddev);
1720 bitmap->daemon_lastrun -= sleep;
1721 md_bitmap_daemon_work(mddev);
1722 bitmap->daemon_lastrun -= sleep;
1723 md_bitmap_daemon_work(mddev);
1724 md_bitmap_update_sb(bitmap);
1725}
1726
1727/*
1728 * free memory that was allocated
1729 */
1730void md_bitmap_free(struct bitmap *bitmap)
1731{
1732 unsigned long k, pages;
1733 struct bitmap_page *bp;
1734
1735 if (!bitmap) /* there was no bitmap */
1736 return;
1737
1738 if (bitmap->sysfs_can_clear)
1739 sysfs_put(bitmap->sysfs_can_clear);
1740
1741 if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
1742 bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
1743 md_cluster_stop(bitmap->mddev);
1744
1745 /* Shouldn't be needed - but just in case.... */
1746 wait_event(bitmap->write_wait,
1747 atomic_read(&bitmap->pending_writes) == 0);
1748
1749 /* release the bitmap file */
1750 md_bitmap_file_unmap(&bitmap->storage);
1751
1752 bp = bitmap->counts.bp;
1753 pages = bitmap->counts.pages;
1754
1755 /* free all allocated memory */
1756
1757 if (bp) /* deallocate the page memory */
1758 for (k = 0; k < pages; k++)
1759 if (bp[k].map && !bp[k].hijacked)
1760 kfree(bp[k].map);
1761 kfree(bp);
1762 kfree(bitmap);
1763}
1764EXPORT_SYMBOL(md_bitmap_free);
1765
1766void md_bitmap_wait_behind_writes(struct mddev *mddev)
1767{
1768 struct bitmap *bitmap = mddev->bitmap;
1769
1770 /* wait for behind writes to complete */
1771 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1772 pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
1773 mdname(mddev));
1774 /* need to kick something here to make sure I/O goes? */
1775 wait_event(bitmap->behind_wait,
1776 atomic_read(&bitmap->behind_writes) == 0);
1777 }
1778}
1779
1780void md_bitmap_destroy(struct mddev *mddev)
1781{
1782 struct bitmap *bitmap = mddev->bitmap;
1783
1784 if (!bitmap) /* there was no bitmap */
1785 return;
1786
1787 md_bitmap_wait_behind_writes(mddev);
1788 if (!mddev->serialize_policy)
1789 mddev_destroy_serial_pool(mddev, NULL, true);
1790
1791 mutex_lock(&mddev->bitmap_info.mutex);
1792 spin_lock(&mddev->lock);
1793 mddev->bitmap = NULL; /* disconnect from the md device */
1794 spin_unlock(&mddev->lock);
1795 mutex_unlock(&mddev->bitmap_info.mutex);
1796 if (mddev->thread)
1797 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1798
1799 md_bitmap_free(bitmap);
1800}
1801
1802/*
1803 * initialize the bitmap structure
1804 * if this returns an error, bitmap_destroy must be called to do clean up
1805 * once mddev->bitmap is set
1806 */
1807struct bitmap *md_bitmap_create(struct mddev *mddev, int slot)
1808{
1809 struct bitmap *bitmap;
1810 sector_t blocks = mddev->resync_max_sectors;
1811 struct file *file = mddev->bitmap_info.file;
1812 int err;
1813 struct kernfs_node *bm = NULL;
1814
1815 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1816
1817 BUG_ON(file && mddev->bitmap_info.offset);
1818
1819 if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
1820 pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
1821 mdname(mddev));
1822 return ERR_PTR(-EBUSY);
1823 }
1824
1825 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1826 if (!bitmap)
1827 return ERR_PTR(-ENOMEM);
1828
1829 spin_lock_init(&bitmap->counts.lock);
1830 atomic_set(&bitmap->pending_writes, 0);
1831 init_waitqueue_head(&bitmap->write_wait);
1832 init_waitqueue_head(&bitmap->overflow_wait);
1833 init_waitqueue_head(&bitmap->behind_wait);
1834
1835 bitmap->mddev = mddev;
1836 bitmap->cluster_slot = slot;
1837
1838 if (mddev->kobj.sd)
1839 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
1840 if (bm) {
1841 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
1842 sysfs_put(bm);
1843 } else
1844 bitmap->sysfs_can_clear = NULL;
1845
1846 bitmap->storage.file = file;
1847 if (file) {
1848 get_file(file);
1849 /* As future accesses to this file will use bmap,
1850 * and bypass the page cache, we must sync the file
1851 * first.
1852 */
1853 vfs_fsync(file, 1);
1854 }
1855 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1856 if (!mddev->bitmap_info.external) {
1857 /*
1858 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1859 * instructing us to create a new on-disk bitmap instance.
1860 */
1861 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1862 err = md_bitmap_new_disk_sb(bitmap);
1863 else
1864 err = md_bitmap_read_sb(bitmap);
1865 } else {
1866 err = 0;
1867 if (mddev->bitmap_info.chunksize == 0 ||
1868 mddev->bitmap_info.daemon_sleep == 0)
1869 /* chunksize and time_base need to be
1870 * set first. */
1871 err = -EINVAL;
1872 }
1873 if (err)
1874 goto error;
1875
1876 bitmap->daemon_lastrun = jiffies;
1877 err = md_bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1878 if (err)
1879 goto error;
1880
1881 pr_debug("created bitmap (%lu pages) for device %s\n",
1882 bitmap->counts.pages, bmname(bitmap));
1883
1884 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1885 if (err)
1886 goto error;
1887
1888 return bitmap;
1889 error:
1890 md_bitmap_free(bitmap);
1891 return ERR_PTR(err);
1892}
1893
1894int md_bitmap_load(struct mddev *mddev)
1895{
1896 int err = 0;
1897 sector_t start = 0;
1898 sector_t sector = 0;
1899 struct bitmap *bitmap = mddev->bitmap;
1900 struct md_rdev *rdev;
1901
1902 if (!bitmap)
1903 goto out;
1904
1905 rdev_for_each(rdev, mddev)
1906 mddev_create_serial_pool(mddev, rdev, true);
1907
1908 if (mddev_is_clustered(mddev))
1909 md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
1910
1911 /* Clear out old bitmap info first: Either there is none, or we
1912 * are resuming after someone else has possibly changed things,
1913 * so we should forget old cached info.
1914 * All chunks should be clean, but some might need_sync.
1915 */
1916 while (sector < mddev->resync_max_sectors) {
1917 sector_t blocks;
1918 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1919 sector += blocks;
1920 }
1921 md_bitmap_close_sync(bitmap);
1922
1923 if (mddev->degraded == 0
1924 || bitmap->events_cleared == mddev->events)
1925 /* no need to keep dirty bits to optimise a
1926 * re-add of a missing device */
1927 start = mddev->recovery_cp;
1928
1929 mutex_lock(&mddev->bitmap_info.mutex);
1930 err = md_bitmap_init_from_disk(bitmap, start);
1931 mutex_unlock(&mddev->bitmap_info.mutex);
1932
1933 if (err)
1934 goto out;
1935 clear_bit(BITMAP_STALE, &bitmap->flags);
1936
1937 /* Kick recovery in case any bits were set */
1938 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1939
1940 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1941 md_wakeup_thread(mddev->thread);
1942
1943 md_bitmap_update_sb(bitmap);
1944
1945 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1946 err = -EIO;
1947out:
1948 return err;
1949}
1950EXPORT_SYMBOL_GPL(md_bitmap_load);
1951
1952struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
1953{
1954 int rv = 0;
1955 struct bitmap *bitmap;
1956
1957 bitmap = md_bitmap_create(mddev, slot);
1958 if (IS_ERR(bitmap)) {
1959 rv = PTR_ERR(bitmap);
1960 return ERR_PTR(rv);
1961 }
1962
1963 rv = md_bitmap_init_from_disk(bitmap, 0);
1964 if (rv) {
1965 md_bitmap_free(bitmap);
1966 return ERR_PTR(rv);
1967 }
1968
1969 return bitmap;
1970}
1971EXPORT_SYMBOL(get_bitmap_from_slot);
1972
1973/* Loads the bitmap associated with slot and copies the resync information
1974 * to our bitmap
1975 */
1976int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
1977 sector_t *low, sector_t *high, bool clear_bits)
1978{
1979 int rv = 0, i, j;
1980 sector_t block, lo = 0, hi = 0;
1981 struct bitmap_counts *counts;
1982 struct bitmap *bitmap;
1983
1984 bitmap = get_bitmap_from_slot(mddev, slot);
1985 if (IS_ERR(bitmap)) {
1986 pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
1987 return -1;
1988 }
1989
1990 counts = &bitmap->counts;
1991 for (j = 0; j < counts->chunks; j++) {
1992 block = (sector_t)j << counts->chunkshift;
1993 if (md_bitmap_file_test_bit(bitmap, block)) {
1994 if (!lo)
1995 lo = block;
1996 hi = block;
1997 md_bitmap_file_clear_bit(bitmap, block);
1998 md_bitmap_set_memory_bits(mddev->bitmap, block, 1);
1999 md_bitmap_file_set_bit(mddev->bitmap, block);
2000 }
2001 }
2002
2003 if (clear_bits) {
2004 md_bitmap_update_sb(bitmap);
2005 /* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
2006 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
2007 for (i = 0; i < bitmap->storage.file_pages; i++)
2008 if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
2009 set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
2010 md_bitmap_unplug(bitmap);
2011 }
2012 md_bitmap_unplug(mddev->bitmap);
2013 *low = lo;
2014 *high = hi;
2015
2016 return rv;
2017}
2018EXPORT_SYMBOL_GPL(md_bitmap_copy_from_slot);
2019
2020
2021void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
2022{
2023 unsigned long chunk_kb;
2024 struct bitmap_counts *counts;
2025
2026 if (!bitmap)
2027 return;
2028
2029 counts = &bitmap->counts;
2030
2031 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
2032 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
2033 "%lu%s chunk",
2034 counts->pages - counts->missing_pages,
2035 counts->pages,
2036 (counts->pages - counts->missing_pages)
2037 << (PAGE_SHIFT - 10),
2038 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
2039 chunk_kb ? "KB" : "B");
2040 if (bitmap->storage.file) {
2041 seq_printf(seq, ", file: ");
2042 seq_file_path(seq, bitmap->storage.file, " \t\n");
2043 }
2044
2045 seq_printf(seq, "\n");
2046}
2047
2048int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
2049 int chunksize, int init)
2050{
2051 /* If chunk_size is 0, choose an appropriate chunk size.
2052 * Then possibly allocate new storage space.
2053 * Then quiesce, copy bits, replace bitmap, and re-start
2054 *
2055 * This function is called both to set up the initial bitmap
2056 * and to resize the bitmap while the array is active.
2057 * If this happens as a result of the array being resized,
2058 * chunksize will be zero, and we need to choose a suitable
2059 * chunksize, otherwise we use what we are given.
2060 */
2061 struct bitmap_storage store;
2062 struct bitmap_counts old_counts;
2063 unsigned long chunks;
2064 sector_t block;
2065 sector_t old_blocks, new_blocks;
2066 int chunkshift;
2067 int ret = 0;
2068 long pages;
2069 struct bitmap_page *new_bp;
2070
2071 if (bitmap->storage.file && !init) {
2072 pr_info("md: cannot resize file-based bitmap\n");
2073 return -EINVAL;
2074 }
2075
2076 if (chunksize == 0) {
2077 /* If there is enough space, leave the chunk size unchanged,
2078 * else increase by factor of two until there is enough space.
2079 */
2080 long bytes;
2081 long space = bitmap->mddev->bitmap_info.space;
2082
2083 if (space == 0) {
2084 /* We don't know how much space there is, so limit
2085 * to current size - in sectors.
2086 */
2087 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
2088 if (!bitmap->mddev->bitmap_info.external)
2089 bytes += sizeof(bitmap_super_t);
2090 space = DIV_ROUND_UP(bytes, 512);
2091 bitmap->mddev->bitmap_info.space = space;
2092 }
2093 chunkshift = bitmap->counts.chunkshift;
2094 chunkshift--;
2095 do {
2096 /* 'chunkshift' is shift from block size to chunk size */
2097 chunkshift++;
2098 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2099 bytes = DIV_ROUND_UP(chunks, 8);
2100 if (!bitmap->mddev->bitmap_info.external)
2101 bytes += sizeof(bitmap_super_t);
2102 } while (bytes > (space << 9));
2103 } else
2104 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
2105
2106 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2107 memset(&store, 0, sizeof(store));
2108 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2109 ret = md_bitmap_storage_alloc(&store, chunks,
2110 !bitmap->mddev->bitmap_info.external,
2111 mddev_is_clustered(bitmap->mddev)
2112 ? bitmap->cluster_slot : 0);
2113 if (ret) {
2114 md_bitmap_file_unmap(&store);
2115 goto err;
2116 }
2117
2118 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2119
2120 new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
2121 ret = -ENOMEM;
2122 if (!new_bp) {
2123 md_bitmap_file_unmap(&store);
2124 goto err;
2125 }
2126
2127 if (!init)
2128 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2129
2130 store.file = bitmap->storage.file;
2131 bitmap->storage.file = NULL;
2132
2133 if (store.sb_page && bitmap->storage.sb_page)
2134 memcpy(page_address(store.sb_page),
2135 page_address(bitmap->storage.sb_page),
2136 sizeof(bitmap_super_t));
2137 spin_lock_irq(&bitmap->counts.lock);
2138 md_bitmap_file_unmap(&bitmap->storage);
2139 bitmap->storage = store;
2140
2141 old_counts = bitmap->counts;
2142 bitmap->counts.bp = new_bp;
2143 bitmap->counts.pages = pages;
2144 bitmap->counts.missing_pages = pages;
2145 bitmap->counts.chunkshift = chunkshift;
2146 bitmap->counts.chunks = chunks;
2147 bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift +
2148 BITMAP_BLOCK_SHIFT);
2149
2150 blocks = min(old_counts.chunks << old_counts.chunkshift,
2151 chunks << chunkshift);
2152
2153 /* For cluster raid, need to pre-allocate bitmap */
2154 if (mddev_is_clustered(bitmap->mddev)) {
2155 unsigned long page;
2156 for (page = 0; page < pages; page++) {
2157 ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1);
2158 if (ret) {
2159 unsigned long k;
2160
2161 /* deallocate the page memory */
2162 for (k = 0; k < page; k++) {
2163 kfree(new_bp[k].map);
2164 }
2165 kfree(new_bp);
2166
2167 /* restore some fields from old_counts */
2168 bitmap->counts.bp = old_counts.bp;
2169 bitmap->counts.pages = old_counts.pages;
2170 bitmap->counts.missing_pages = old_counts.pages;
2171 bitmap->counts.chunkshift = old_counts.chunkshift;
2172 bitmap->counts.chunks = old_counts.chunks;
2173 bitmap->mddev->bitmap_info.chunksize = 1 << (old_counts.chunkshift +
2174 BITMAP_BLOCK_SHIFT);
2175 blocks = old_counts.chunks << old_counts.chunkshift;
2176 pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
2177 break;
2178 } else
2179 bitmap->counts.bp[page].count += 1;
2180 }
2181 }
2182
2183 for (block = 0; block < blocks; ) {
2184 bitmap_counter_t *bmc_old, *bmc_new;
2185 int set;
2186
2187 bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0);
2188 set = bmc_old && NEEDED(*bmc_old);
2189
2190 if (set) {
2191 bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2192 if (*bmc_new == 0) {
2193 /* need to set on-disk bits too. */
2194 sector_t end = block + new_blocks;
2195 sector_t start = block >> chunkshift;
2196 start <<= chunkshift;
2197 while (start < end) {
2198 md_bitmap_file_set_bit(bitmap, block);
2199 start += 1 << chunkshift;
2200 }
2201 *bmc_new = 2;
2202 md_bitmap_count_page(&bitmap->counts, block, 1);
2203 md_bitmap_set_pending(&bitmap->counts, block);
2204 }
2205 *bmc_new |= NEEDED_MASK;
2206 if (new_blocks < old_blocks)
2207 old_blocks = new_blocks;
2208 }
2209 block += old_blocks;
2210 }
2211
2212 if (bitmap->counts.bp != old_counts.bp) {
2213 unsigned long k;
2214 for (k = 0; k < old_counts.pages; k++)
2215 if (!old_counts.bp[k].hijacked)
2216 kfree(old_counts.bp[k].map);
2217 kfree(old_counts.bp);
2218 }
2219
2220 if (!init) {
2221 int i;
2222 while (block < (chunks << chunkshift)) {
2223 bitmap_counter_t *bmc;
2224 bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2225 if (bmc) {
2226 /* new space. It needs to be resynced, so
2227 * we set NEEDED_MASK.
2228 */
2229 if (*bmc == 0) {
2230 *bmc = NEEDED_MASK | 2;
2231 md_bitmap_count_page(&bitmap->counts, block, 1);
2232 md_bitmap_set_pending(&bitmap->counts, block);
2233 }
2234 }
2235 block += new_blocks;
2236 }
2237 for (i = 0; i < bitmap->storage.file_pages; i++)
2238 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
2239 }
2240 spin_unlock_irq(&bitmap->counts.lock);
2241
2242 if (!init) {
2243 md_bitmap_unplug(bitmap);
2244 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2245 }
2246 ret = 0;
2247err:
2248 return ret;
2249}
2250EXPORT_SYMBOL_GPL(md_bitmap_resize);
2251
2252static ssize_t
2253location_show(struct mddev *mddev, char *page)
2254{
2255 ssize_t len;
2256 if (mddev->bitmap_info.file)
2257 len = sprintf(page, "file");
2258 else if (mddev->bitmap_info.offset)
2259 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
2260 else
2261 len = sprintf(page, "none");
2262 len += sprintf(page+len, "\n");
2263 return len;
2264}
2265
2266static ssize_t
2267location_store(struct mddev *mddev, const char *buf, size_t len)
2268{
2269 int rv;
2270
2271 rv = mddev_lock(mddev);
2272 if (rv)
2273 return rv;
2274 if (mddev->pers) {
2275 if (!mddev->pers->quiesce) {
2276 rv = -EBUSY;
2277 goto out;
2278 }
2279 if (mddev->recovery || mddev->sync_thread) {
2280 rv = -EBUSY;
2281 goto out;
2282 }
2283 }
2284
2285 if (mddev->bitmap || mddev->bitmap_info.file ||
2286 mddev->bitmap_info.offset) {
2287 /* bitmap already configured. Only option is to clear it */
2288 if (strncmp(buf, "none", 4) != 0) {
2289 rv = -EBUSY;
2290 goto out;
2291 }
2292 if (mddev->pers) {
2293 mddev_suspend(mddev);
2294 md_bitmap_destroy(mddev);
2295 mddev_resume(mddev);
2296 }
2297 mddev->bitmap_info.offset = 0;
2298 if (mddev->bitmap_info.file) {
2299 struct file *f = mddev->bitmap_info.file;
2300 mddev->bitmap_info.file = NULL;
2301 fput(f);
2302 }
2303 } else {
2304 /* No bitmap, OK to set a location */
2305 long long offset;
2306 if (strncmp(buf, "none", 4) == 0)
2307 /* nothing to be done */;
2308 else if (strncmp(buf, "file:", 5) == 0) {
2309 /* Not supported yet */
2310 rv = -EINVAL;
2311 goto out;
2312 } else {
2313 if (buf[0] == '+')
2314 rv = kstrtoll(buf+1, 10, &offset);
2315 else
2316 rv = kstrtoll(buf, 10, &offset);
2317 if (rv)
2318 goto out;
2319 if (offset == 0) {
2320 rv = -EINVAL;
2321 goto out;
2322 }
2323 if (mddev->bitmap_info.external == 0 &&
2324 mddev->major_version == 0 &&
2325 offset != mddev->bitmap_info.default_offset) {
2326 rv = -EINVAL;
2327 goto out;
2328 }
2329 mddev->bitmap_info.offset = offset;
2330 if (mddev->pers) {
2331 struct bitmap *bitmap;
2332 bitmap = md_bitmap_create(mddev, -1);
2333 mddev_suspend(mddev);
2334 if (IS_ERR(bitmap))
2335 rv = PTR_ERR(bitmap);
2336 else {
2337 mddev->bitmap = bitmap;
2338 rv = md_bitmap_load(mddev);
2339 if (rv)
2340 mddev->bitmap_info.offset = 0;
2341 }
2342 if (rv) {
2343 md_bitmap_destroy(mddev);
2344 mddev_resume(mddev);
2345 goto out;
2346 }
2347 mddev_resume(mddev);
2348 }
2349 }
2350 }
2351 if (!mddev->external) {
2352 /* Ensure new bitmap info is stored in
2353 * metadata promptly.
2354 */
2355 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2356 md_wakeup_thread(mddev->thread);
2357 }
2358 rv = 0;
2359out:
2360 mddev_unlock(mddev);
2361 if (rv)
2362 return rv;
2363 return len;
2364}
2365
2366static struct md_sysfs_entry bitmap_location =
2367__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2368
2369/* 'bitmap/space' is the space available at 'location' for the
2370 * bitmap. This allows the kernel to know when it is safe to
2371 * resize the bitmap to match a resized array.
2372 */
2373static ssize_t
2374space_show(struct mddev *mddev, char *page)
2375{
2376 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2377}
2378
2379static ssize_t
2380space_store(struct mddev *mddev, const char *buf, size_t len)
2381{
2382 unsigned long sectors;
2383 int rv;
2384
2385 rv = kstrtoul(buf, 10, §ors);
2386 if (rv)
2387 return rv;
2388
2389 if (sectors == 0)
2390 return -EINVAL;
2391
2392 if (mddev->bitmap &&
2393 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2394 return -EFBIG; /* Bitmap is too big for this small space */
2395
2396 /* could make sure it isn't too big, but that isn't really
2397 * needed - user-space should be careful.
2398 */
2399 mddev->bitmap_info.space = sectors;
2400 return len;
2401}
2402
2403static struct md_sysfs_entry bitmap_space =
2404__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2405
2406static ssize_t
2407timeout_show(struct mddev *mddev, char *page)
2408{
2409 ssize_t len;
2410 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2411 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2412
2413 len = sprintf(page, "%lu", secs);
2414 if (jifs)
2415 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2416 len += sprintf(page+len, "\n");
2417 return len;
2418}
2419
2420static ssize_t
2421timeout_store(struct mddev *mddev, const char *buf, size_t len)
2422{
2423 /* timeout can be set at any time */
2424 unsigned long timeout;
2425 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2426 if (rv)
2427 return rv;
2428
2429 /* just to make sure we don't overflow... */
2430 if (timeout >= LONG_MAX / HZ)
2431 return -EINVAL;
2432
2433 timeout = timeout * HZ / 10000;
2434
2435 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2436 timeout = MAX_SCHEDULE_TIMEOUT-1;
2437 if (timeout < 1)
2438 timeout = 1;
2439 mddev->bitmap_info.daemon_sleep = timeout;
2440 if (mddev->thread) {
2441 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
2442 * the bitmap is all clean and we don't need to
2443 * adjust the timeout right now
2444 */
2445 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2446 mddev->thread->timeout = timeout;
2447 md_wakeup_thread(mddev->thread);
2448 }
2449 }
2450 return len;
2451}
2452
2453static struct md_sysfs_entry bitmap_timeout =
2454__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2455
2456static ssize_t
2457backlog_show(struct mddev *mddev, char *page)
2458{
2459 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2460}
2461
2462static ssize_t
2463backlog_store(struct mddev *mddev, const char *buf, size_t len)
2464{
2465 unsigned long backlog;
2466 unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
2467 int rv = kstrtoul(buf, 10, &backlog);
2468 if (rv)
2469 return rv;
2470 if (backlog > COUNTER_MAX)
2471 return -EINVAL;
2472 mddev->bitmap_info.max_write_behind = backlog;
2473 if (!backlog && mddev->serial_info_pool) {
2474 /* serial_info_pool is not needed if backlog is zero */
2475 if (!mddev->serialize_policy)
2476 mddev_destroy_serial_pool(mddev, NULL, false);
2477 } else if (backlog && !mddev->serial_info_pool) {
2478 /* serial_info_pool is needed since backlog is not zero */
2479 struct md_rdev *rdev;
2480
2481 rdev_for_each(rdev, mddev)
2482 mddev_create_serial_pool(mddev, rdev, false);
2483 }
2484 if (old_mwb != backlog)
2485 md_bitmap_update_sb(mddev->bitmap);
2486 return len;
2487}
2488
2489static struct md_sysfs_entry bitmap_backlog =
2490__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2491
2492static ssize_t
2493chunksize_show(struct mddev *mddev, char *page)
2494{
2495 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2496}
2497
2498static ssize_t
2499chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2500{
2501 /* Can only be changed when no bitmap is active */
2502 int rv;
2503 unsigned long csize;
2504 if (mddev->bitmap)
2505 return -EBUSY;
2506 rv = kstrtoul(buf, 10, &csize);
2507 if (rv)
2508 return rv;
2509 if (csize < 512 ||
2510 !is_power_of_2(csize))
2511 return -EINVAL;
2512 mddev->bitmap_info.chunksize = csize;
2513 return len;
2514}
2515
2516static struct md_sysfs_entry bitmap_chunksize =
2517__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2518
2519static ssize_t metadata_show(struct mddev *mddev, char *page)
2520{
2521 if (mddev_is_clustered(mddev))
2522 return sprintf(page, "clustered\n");
2523 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2524 ? "external" : "internal"));
2525}
2526
2527static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2528{
2529 if (mddev->bitmap ||
2530 mddev->bitmap_info.file ||
2531 mddev->bitmap_info.offset)
2532 return -EBUSY;
2533 if (strncmp(buf, "external", 8) == 0)
2534 mddev->bitmap_info.external = 1;
2535 else if ((strncmp(buf, "internal", 8) == 0) ||
2536 (strncmp(buf, "clustered", 9) == 0))
2537 mddev->bitmap_info.external = 0;
2538 else
2539 return -EINVAL;
2540 return len;
2541}
2542
2543static struct md_sysfs_entry bitmap_metadata =
2544__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2545
2546static ssize_t can_clear_show(struct mddev *mddev, char *page)
2547{
2548 int len;
2549 spin_lock(&mddev->lock);
2550 if (mddev->bitmap)
2551 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2552 "false" : "true"));
2553 else
2554 len = sprintf(page, "\n");
2555 spin_unlock(&mddev->lock);
2556 return len;
2557}
2558
2559static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2560{
2561 if (mddev->bitmap == NULL)
2562 return -ENOENT;
2563 if (strncmp(buf, "false", 5) == 0)
2564 mddev->bitmap->need_sync = 1;
2565 else if (strncmp(buf, "true", 4) == 0) {
2566 if (mddev->degraded)
2567 return -EBUSY;
2568 mddev->bitmap->need_sync = 0;
2569 } else
2570 return -EINVAL;
2571 return len;
2572}
2573
2574static struct md_sysfs_entry bitmap_can_clear =
2575__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2576
2577static ssize_t
2578behind_writes_used_show(struct mddev *mddev, char *page)
2579{
2580 ssize_t ret;
2581 spin_lock(&mddev->lock);
2582 if (mddev->bitmap == NULL)
2583 ret = sprintf(page, "0\n");
2584 else
2585 ret = sprintf(page, "%lu\n",
2586 mddev->bitmap->behind_writes_used);
2587 spin_unlock(&mddev->lock);
2588 return ret;
2589}
2590
2591static ssize_t
2592behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2593{
2594 if (mddev->bitmap)
2595 mddev->bitmap->behind_writes_used = 0;
2596 return len;
2597}
2598
2599static struct md_sysfs_entry max_backlog_used =
2600__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2601 behind_writes_used_show, behind_writes_used_reset);
2602
2603static struct attribute *md_bitmap_attrs[] = {
2604 &bitmap_location.attr,
2605 &bitmap_space.attr,
2606 &bitmap_timeout.attr,
2607 &bitmap_backlog.attr,
2608 &bitmap_chunksize.attr,
2609 &bitmap_metadata.attr,
2610 &bitmap_can_clear.attr,
2611 &max_backlog_used.attr,
2612 NULL
2613};
2614struct attribute_group md_bitmap_group = {
2615 .name = "bitmap",
2616 .attrs = md_bitmap_attrs,
2617};
2618
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
4 *
5 * bitmap_create - sets up the bitmap structure
6 * bitmap_destroy - destroys the bitmap structure
7 *
8 * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
9 * - added disk storage for bitmap
10 * - changes to allow various bitmap chunk sizes
11 */
12
13/*
14 * Still to do:
15 *
16 * flush after percent set rather than just time based. (maybe both).
17 */
18
19#include <linux/blkdev.h>
20#include <linux/module.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/init.h>
24#include <linux/timer.h>
25#include <linux/sched.h>
26#include <linux/list.h>
27#include <linux/file.h>
28#include <linux/mount.h>
29#include <linux/buffer_head.h>
30#include <linux/seq_file.h>
31#include <trace/events/block.h>
32#include "md.h"
33#include "md-bitmap.h"
34
35static inline char *bmname(struct bitmap *bitmap)
36{
37 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
38}
39
40/*
41 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
42 *
43 * 1) check to see if this page is allocated, if it's not then try to alloc
44 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
45 * page pointer directly as a counter
46 *
47 * if we find our page, we increment the page's refcount so that it stays
48 * allocated while we're using it
49 */
50static int md_bitmap_checkpage(struct bitmap_counts *bitmap,
51 unsigned long page, int create, int no_hijack)
52__releases(bitmap->lock)
53__acquires(bitmap->lock)
54{
55 unsigned char *mappage;
56
57 if (page >= bitmap->pages) {
58 /* This can happen if bitmap_start_sync goes beyond
59 * End-of-device while looking for a whole page.
60 * It is harmless.
61 */
62 return -EINVAL;
63 }
64
65 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
66 return 0;
67
68 if (bitmap->bp[page].map) /* page is already allocated, just return */
69 return 0;
70
71 if (!create)
72 return -ENOENT;
73
74 /* this page has not been allocated yet */
75
76 spin_unlock_irq(&bitmap->lock);
77 /* It is possible that this is being called inside a
78 * prepare_to_wait/finish_wait loop from raid5c:make_request().
79 * In general it is not permitted to sleep in that context as it
80 * can cause the loop to spin freely.
81 * That doesn't apply here as we can only reach this point
82 * once with any loop.
83 * When this function completes, either bp[page].map or
84 * bp[page].hijacked. In either case, this function will
85 * abort before getting to this point again. So there is
86 * no risk of a free-spin, and so it is safe to assert
87 * that sleeping here is allowed.
88 */
89 sched_annotate_sleep();
90 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
91 spin_lock_irq(&bitmap->lock);
92
93 if (mappage == NULL) {
94 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
95 /* We don't support hijack for cluster raid */
96 if (no_hijack)
97 return -ENOMEM;
98 /* failed - set the hijacked flag so that we can use the
99 * pointer as a counter */
100 if (!bitmap->bp[page].map)
101 bitmap->bp[page].hijacked = 1;
102 } else if (bitmap->bp[page].map ||
103 bitmap->bp[page].hijacked) {
104 /* somebody beat us to getting the page */
105 kfree(mappage);
106 } else {
107
108 /* no page was in place and we have one, so install it */
109
110 bitmap->bp[page].map = mappage;
111 bitmap->missing_pages--;
112 }
113 return 0;
114}
115
116/* if page is completely empty, put it back on the free list, or dealloc it */
117/* if page was hijacked, unmark the flag so it might get alloced next time */
118/* Note: lock should be held when calling this */
119static void md_bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
120{
121 char *ptr;
122
123 if (bitmap->bp[page].count) /* page is still busy */
124 return;
125
126 /* page is no longer in use, it can be released */
127
128 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
129 bitmap->bp[page].hijacked = 0;
130 bitmap->bp[page].map = NULL;
131 } else {
132 /* normal case, free the page */
133 ptr = bitmap->bp[page].map;
134 bitmap->bp[page].map = NULL;
135 bitmap->missing_pages++;
136 kfree(ptr);
137 }
138}
139
140/*
141 * bitmap file handling - read and write the bitmap file and its superblock
142 */
143
144/*
145 * basic page I/O operations
146 */
147
148/* IO operations when bitmap is stored near all superblocks */
149static int read_sb_page(struct mddev *mddev, loff_t offset,
150 struct page *page,
151 unsigned long index, int size)
152{
153 /* choose a good rdev and read the page from there */
154
155 struct md_rdev *rdev;
156 sector_t target;
157
158 rdev_for_each(rdev, mddev) {
159 if (! test_bit(In_sync, &rdev->flags)
160 || test_bit(Faulty, &rdev->flags)
161 || test_bit(Bitmap_sync, &rdev->flags))
162 continue;
163
164 target = offset + index * (PAGE_SIZE/512);
165
166 if (sync_page_io(rdev, target,
167 roundup(size, bdev_logical_block_size(rdev->bdev)),
168 page, REQ_OP_READ, 0, true)) {
169 page->index = index;
170 return 0;
171 }
172 }
173 return -EIO;
174}
175
176static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
177{
178 /* Iterate the disks of an mddev, using rcu to protect access to the
179 * linked list, and raising the refcount of devices we return to ensure
180 * they don't disappear while in use.
181 * As devices are only added or removed when raid_disk is < 0 and
182 * nr_pending is 0 and In_sync is clear, the entries we return will
183 * still be in the same position on the list when we re-enter
184 * list_for_each_entry_continue_rcu.
185 *
186 * Note that if entered with 'rdev == NULL' to start at the
187 * beginning, we temporarily assign 'rdev' to an address which
188 * isn't really an rdev, but which can be used by
189 * list_for_each_entry_continue_rcu() to find the first entry.
190 */
191 rcu_read_lock();
192 if (rdev == NULL)
193 /* start at the beginning */
194 rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
195 else {
196 /* release the previous rdev and start from there. */
197 rdev_dec_pending(rdev, mddev);
198 }
199 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
200 if (rdev->raid_disk >= 0 &&
201 !test_bit(Faulty, &rdev->flags)) {
202 /* this is a usable devices */
203 atomic_inc(&rdev->nr_pending);
204 rcu_read_unlock();
205 return rdev;
206 }
207 }
208 rcu_read_unlock();
209 return NULL;
210}
211
212static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
213{
214 struct md_rdev *rdev;
215 struct block_device *bdev;
216 struct mddev *mddev = bitmap->mddev;
217 struct bitmap_storage *store = &bitmap->storage;
218
219restart:
220 rdev = NULL;
221 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
222 int size = PAGE_SIZE;
223 loff_t offset = mddev->bitmap_info.offset;
224
225 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
226
227 if (page->index == store->file_pages-1) {
228 int last_page_size = store->bytes & (PAGE_SIZE-1);
229 if (last_page_size == 0)
230 last_page_size = PAGE_SIZE;
231 size = roundup(last_page_size,
232 bdev_logical_block_size(bdev));
233 }
234 /* Just make sure we aren't corrupting data or
235 * metadata
236 */
237 if (mddev->external) {
238 /* Bitmap could be anywhere. */
239 if (rdev->sb_start + offset + (page->index
240 * (PAGE_SIZE/512))
241 > rdev->data_offset
242 &&
243 rdev->sb_start + offset
244 < (rdev->data_offset + mddev->dev_sectors
245 + (PAGE_SIZE/512)))
246 goto bad_alignment;
247 } else if (offset < 0) {
248 /* DATA BITMAP METADATA */
249 if (offset
250 + (long)(page->index * (PAGE_SIZE/512))
251 + size/512 > 0)
252 /* bitmap runs in to metadata */
253 goto bad_alignment;
254 if (rdev->data_offset + mddev->dev_sectors
255 > rdev->sb_start + offset)
256 /* data runs in to bitmap */
257 goto bad_alignment;
258 } else if (rdev->sb_start < rdev->data_offset) {
259 /* METADATA BITMAP DATA */
260 if (rdev->sb_start
261 + offset
262 + page->index*(PAGE_SIZE/512) + size/512
263 > rdev->data_offset)
264 /* bitmap runs in to data */
265 goto bad_alignment;
266 } else {
267 /* DATA METADATA BITMAP - no problems */
268 }
269 md_super_write(mddev, rdev,
270 rdev->sb_start + offset
271 + page->index * (PAGE_SIZE/512),
272 size,
273 page);
274 }
275
276 if (wait && md_super_wait(mddev) < 0)
277 goto restart;
278 return 0;
279
280 bad_alignment:
281 return -EINVAL;
282}
283
284static void md_bitmap_file_kick(struct bitmap *bitmap);
285/*
286 * write out a page to a file
287 */
288static void write_page(struct bitmap *bitmap, struct page *page, int wait)
289{
290 struct buffer_head *bh;
291
292 if (bitmap->storage.file == NULL) {
293 switch (write_sb_page(bitmap, page, wait)) {
294 case -EINVAL:
295 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
296 }
297 } else {
298
299 bh = page_buffers(page);
300
301 while (bh && bh->b_blocknr) {
302 atomic_inc(&bitmap->pending_writes);
303 set_buffer_locked(bh);
304 set_buffer_mapped(bh);
305 submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
306 bh = bh->b_this_page;
307 }
308
309 if (wait)
310 wait_event(bitmap->write_wait,
311 atomic_read(&bitmap->pending_writes)==0);
312 }
313 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
314 md_bitmap_file_kick(bitmap);
315}
316
317static void end_bitmap_write(struct buffer_head *bh, int uptodate)
318{
319 struct bitmap *bitmap = bh->b_private;
320
321 if (!uptodate)
322 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
323 if (atomic_dec_and_test(&bitmap->pending_writes))
324 wake_up(&bitmap->write_wait);
325}
326
327/* copied from buffer.c */
328static void
329__clear_page_buffers(struct page *page)
330{
331 ClearPagePrivate(page);
332 set_page_private(page, 0);
333 put_page(page);
334}
335static void free_buffers(struct page *page)
336{
337 struct buffer_head *bh;
338
339 if (!PagePrivate(page))
340 return;
341
342 bh = page_buffers(page);
343 while (bh) {
344 struct buffer_head *next = bh->b_this_page;
345 free_buffer_head(bh);
346 bh = next;
347 }
348 __clear_page_buffers(page);
349 put_page(page);
350}
351
352/* read a page from a file.
353 * We both read the page, and attach buffers to the page to record the
354 * address of each block (using bmap). These addresses will be used
355 * to write the block later, completely bypassing the filesystem.
356 * This usage is similar to how swap files are handled, and allows us
357 * to write to a file with no concerns of memory allocation failing.
358 */
359static int read_page(struct file *file, unsigned long index,
360 struct bitmap *bitmap,
361 unsigned long count,
362 struct page *page)
363{
364 int ret = 0;
365 struct inode *inode = file_inode(file);
366 struct buffer_head *bh;
367 sector_t block;
368
369 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
370 (unsigned long long)index << PAGE_SHIFT);
371
372 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, false);
373 if (!bh) {
374 ret = -ENOMEM;
375 goto out;
376 }
377 attach_page_buffers(page, bh);
378 block = index << (PAGE_SHIFT - inode->i_blkbits);
379 while (bh) {
380 if (count == 0)
381 bh->b_blocknr = 0;
382 else {
383 bh->b_blocknr = bmap(inode, block);
384 if (bh->b_blocknr == 0) {
385 /* Cannot use this file! */
386 ret = -EINVAL;
387 goto out;
388 }
389 bh->b_bdev = inode->i_sb->s_bdev;
390 if (count < (1<<inode->i_blkbits))
391 count = 0;
392 else
393 count -= (1<<inode->i_blkbits);
394
395 bh->b_end_io = end_bitmap_write;
396 bh->b_private = bitmap;
397 atomic_inc(&bitmap->pending_writes);
398 set_buffer_locked(bh);
399 set_buffer_mapped(bh);
400 submit_bh(REQ_OP_READ, 0, bh);
401 }
402 block++;
403 bh = bh->b_this_page;
404 }
405 page->index = index;
406
407 wait_event(bitmap->write_wait,
408 atomic_read(&bitmap->pending_writes)==0);
409 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
410 ret = -EIO;
411out:
412 if (ret)
413 pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
414 (int)PAGE_SIZE,
415 (unsigned long long)index << PAGE_SHIFT,
416 ret);
417 return ret;
418}
419
420/*
421 * bitmap file superblock operations
422 */
423
424/*
425 * md_bitmap_wait_writes() should be called before writing any bitmap
426 * blocks, to ensure previous writes, particularly from
427 * md_bitmap_daemon_work(), have completed.
428 */
429static void md_bitmap_wait_writes(struct bitmap *bitmap)
430{
431 if (bitmap->storage.file)
432 wait_event(bitmap->write_wait,
433 atomic_read(&bitmap->pending_writes)==0);
434 else
435 /* Note that we ignore the return value. The writes
436 * might have failed, but that would just mean that
437 * some bits which should be cleared haven't been,
438 * which is safe. The relevant bitmap blocks will
439 * probably get written again, but there is no great
440 * loss if they aren't.
441 */
442 md_super_wait(bitmap->mddev);
443}
444
445
446/* update the event counter and sync the superblock to disk */
447void md_bitmap_update_sb(struct bitmap *bitmap)
448{
449 bitmap_super_t *sb;
450
451 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
452 return;
453 if (bitmap->mddev->bitmap_info.external)
454 return;
455 if (!bitmap->storage.sb_page) /* no superblock */
456 return;
457 sb = kmap_atomic(bitmap->storage.sb_page);
458 sb->events = cpu_to_le64(bitmap->mddev->events);
459 if (bitmap->mddev->events < bitmap->events_cleared)
460 /* rocking back to read-only */
461 bitmap->events_cleared = bitmap->mddev->events;
462 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
463 /*
464 * clear BITMAP_WRITE_ERROR bit to protect against the case that
465 * a bitmap write error occurred but the later writes succeeded.
466 */
467 sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR));
468 /* Just in case these have been changed via sysfs: */
469 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
470 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
471 /* This might have been changed by a reshape */
472 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
473 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
474 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
475 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
476 bitmap_info.space);
477 kunmap_atomic(sb);
478 write_page(bitmap, bitmap->storage.sb_page, 1);
479}
480EXPORT_SYMBOL(md_bitmap_update_sb);
481
482/* print out the bitmap file superblock */
483void md_bitmap_print_sb(struct bitmap *bitmap)
484{
485 bitmap_super_t *sb;
486
487 if (!bitmap || !bitmap->storage.sb_page)
488 return;
489 sb = kmap_atomic(bitmap->storage.sb_page);
490 pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
491 pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic));
492 pr_debug(" version: %d\n", le32_to_cpu(sb->version));
493 pr_debug(" uuid: %08x.%08x.%08x.%08x\n",
494 le32_to_cpu(*(__le32 *)(sb->uuid+0)),
495 le32_to_cpu(*(__le32 *)(sb->uuid+4)),
496 le32_to_cpu(*(__le32 *)(sb->uuid+8)),
497 le32_to_cpu(*(__le32 *)(sb->uuid+12)));
498 pr_debug(" events: %llu\n",
499 (unsigned long long) le64_to_cpu(sb->events));
500 pr_debug("events cleared: %llu\n",
501 (unsigned long long) le64_to_cpu(sb->events_cleared));
502 pr_debug(" state: %08x\n", le32_to_cpu(sb->state));
503 pr_debug(" chunksize: %d B\n", le32_to_cpu(sb->chunksize));
504 pr_debug(" daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
505 pr_debug(" sync size: %llu KB\n",
506 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
507 pr_debug("max write behind: %d\n", le32_to_cpu(sb->write_behind));
508 kunmap_atomic(sb);
509}
510
511/*
512 * bitmap_new_disk_sb
513 * @bitmap
514 *
515 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
516 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
517 * This function verifies 'bitmap_info' and populates the on-disk bitmap
518 * structure, which is to be written to disk.
519 *
520 * Returns: 0 on success, -Exxx on error
521 */
522static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
523{
524 bitmap_super_t *sb;
525 unsigned long chunksize, daemon_sleep, write_behind;
526
527 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
528 if (bitmap->storage.sb_page == NULL)
529 return -ENOMEM;
530 bitmap->storage.sb_page->index = 0;
531
532 sb = kmap_atomic(bitmap->storage.sb_page);
533
534 sb->magic = cpu_to_le32(BITMAP_MAGIC);
535 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
536
537 chunksize = bitmap->mddev->bitmap_info.chunksize;
538 BUG_ON(!chunksize);
539 if (!is_power_of_2(chunksize)) {
540 kunmap_atomic(sb);
541 pr_warn("bitmap chunksize not a power of 2\n");
542 return -EINVAL;
543 }
544 sb->chunksize = cpu_to_le32(chunksize);
545
546 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
547 if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
548 pr_debug("Choosing daemon_sleep default (5 sec)\n");
549 daemon_sleep = 5 * HZ;
550 }
551 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
552 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
553
554 /*
555 * FIXME: write_behind for RAID1. If not specified, what
556 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
557 */
558 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
559 if (write_behind > COUNTER_MAX)
560 write_behind = COUNTER_MAX / 2;
561 sb->write_behind = cpu_to_le32(write_behind);
562 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
563
564 /* keep the array size field of the bitmap superblock up to date */
565 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
566
567 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
568
569 set_bit(BITMAP_STALE, &bitmap->flags);
570 sb->state = cpu_to_le32(bitmap->flags);
571 bitmap->events_cleared = bitmap->mddev->events;
572 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
573 bitmap->mddev->bitmap_info.nodes = 0;
574
575 kunmap_atomic(sb);
576
577 return 0;
578}
579
580/* read the superblock from the bitmap file and initialize some bitmap fields */
581static int md_bitmap_read_sb(struct bitmap *bitmap)
582{
583 char *reason = NULL;
584 bitmap_super_t *sb;
585 unsigned long chunksize, daemon_sleep, write_behind;
586 unsigned long long events;
587 int nodes = 0;
588 unsigned long sectors_reserved = 0;
589 int err = -EINVAL;
590 struct page *sb_page;
591 loff_t offset = bitmap->mddev->bitmap_info.offset;
592
593 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
594 chunksize = 128 * 1024 * 1024;
595 daemon_sleep = 5 * HZ;
596 write_behind = 0;
597 set_bit(BITMAP_STALE, &bitmap->flags);
598 err = 0;
599 goto out_no_sb;
600 }
601 /* page 0 is the superblock, read it... */
602 sb_page = alloc_page(GFP_KERNEL);
603 if (!sb_page)
604 return -ENOMEM;
605 bitmap->storage.sb_page = sb_page;
606
607re_read:
608 /* If cluster_slot is set, the cluster is setup */
609 if (bitmap->cluster_slot >= 0) {
610 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
611
612 sector_div(bm_blocks,
613 bitmap->mddev->bitmap_info.chunksize >> 9);
614 /* bits to bytes */
615 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
616 /* to 4k blocks */
617 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
618 offset = bitmap->mddev->bitmap_info.offset + (bitmap->cluster_slot * (bm_blocks << 3));
619 pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
620 bitmap->cluster_slot, offset);
621 }
622
623 if (bitmap->storage.file) {
624 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
625 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
626
627 err = read_page(bitmap->storage.file, 0,
628 bitmap, bytes, sb_page);
629 } else {
630 err = read_sb_page(bitmap->mddev,
631 offset,
632 sb_page,
633 0, sizeof(bitmap_super_t));
634 }
635 if (err)
636 return err;
637
638 err = -EINVAL;
639 sb = kmap_atomic(sb_page);
640
641 chunksize = le32_to_cpu(sb->chunksize);
642 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
643 write_behind = le32_to_cpu(sb->write_behind);
644 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
645 /* Setup nodes/clustername only if bitmap version is
646 * cluster-compatible
647 */
648 if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
649 nodes = le32_to_cpu(sb->nodes);
650 strlcpy(bitmap->mddev->bitmap_info.cluster_name,
651 sb->cluster_name, 64);
652 }
653
654 /* verify that the bitmap-specific fields are valid */
655 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
656 reason = "bad magic";
657 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
658 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
659 reason = "unrecognized superblock version";
660 else if (chunksize < 512)
661 reason = "bitmap chunksize too small";
662 else if (!is_power_of_2(chunksize))
663 reason = "bitmap chunksize not a power of 2";
664 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
665 reason = "daemon sleep period out of range";
666 else if (write_behind > COUNTER_MAX)
667 reason = "write-behind limit out of range (0 - 16383)";
668 if (reason) {
669 pr_warn("%s: invalid bitmap file superblock: %s\n",
670 bmname(bitmap), reason);
671 goto out;
672 }
673
674 /* keep the array size field of the bitmap superblock up to date */
675 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
676
677 if (bitmap->mddev->persistent) {
678 /*
679 * We have a persistent array superblock, so compare the
680 * bitmap's UUID and event counter to the mddev's
681 */
682 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
683 pr_warn("%s: bitmap superblock UUID mismatch\n",
684 bmname(bitmap));
685 goto out;
686 }
687 events = le64_to_cpu(sb->events);
688 if (!nodes && (events < bitmap->mddev->events)) {
689 pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
690 bmname(bitmap), events,
691 (unsigned long long) bitmap->mddev->events);
692 set_bit(BITMAP_STALE, &bitmap->flags);
693 }
694 }
695
696 /* assign fields using values from superblock */
697 bitmap->flags |= le32_to_cpu(sb->state);
698 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
699 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
700 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
701 strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
702 err = 0;
703
704out:
705 kunmap_atomic(sb);
706 /* Assigning chunksize is required for "re_read" */
707 bitmap->mddev->bitmap_info.chunksize = chunksize;
708 if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
709 err = md_setup_cluster(bitmap->mddev, nodes);
710 if (err) {
711 pr_warn("%s: Could not setup cluster service (%d)\n",
712 bmname(bitmap), err);
713 goto out_no_sb;
714 }
715 bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
716 goto re_read;
717 }
718
719
720out_no_sb:
721 if (test_bit(BITMAP_STALE, &bitmap->flags))
722 bitmap->events_cleared = bitmap->mddev->events;
723 bitmap->mddev->bitmap_info.chunksize = chunksize;
724 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
725 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
726 bitmap->mddev->bitmap_info.nodes = nodes;
727 if (bitmap->mddev->bitmap_info.space == 0 ||
728 bitmap->mddev->bitmap_info.space > sectors_reserved)
729 bitmap->mddev->bitmap_info.space = sectors_reserved;
730 if (err) {
731 md_bitmap_print_sb(bitmap);
732 if (bitmap->cluster_slot < 0)
733 md_cluster_stop(bitmap->mddev);
734 }
735 return err;
736}
737
738/*
739 * general bitmap file operations
740 */
741
742/*
743 * on-disk bitmap:
744 *
745 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
746 * file a page at a time. There's a superblock at the start of the file.
747 */
748/* calculate the index of the page that contains this bit */
749static inline unsigned long file_page_index(struct bitmap_storage *store,
750 unsigned long chunk)
751{
752 if (store->sb_page)
753 chunk += sizeof(bitmap_super_t) << 3;
754 return chunk >> PAGE_BIT_SHIFT;
755}
756
757/* calculate the (bit) offset of this bit within a page */
758static inline unsigned long file_page_offset(struct bitmap_storage *store,
759 unsigned long chunk)
760{
761 if (store->sb_page)
762 chunk += sizeof(bitmap_super_t) << 3;
763 return chunk & (PAGE_BITS - 1);
764}
765
766/*
767 * return a pointer to the page in the filemap that contains the given bit
768 *
769 */
770static inline struct page *filemap_get_page(struct bitmap_storage *store,
771 unsigned long chunk)
772{
773 if (file_page_index(store, chunk) >= store->file_pages)
774 return NULL;
775 return store->filemap[file_page_index(store, chunk)];
776}
777
778static int md_bitmap_storage_alloc(struct bitmap_storage *store,
779 unsigned long chunks, int with_super,
780 int slot_number)
781{
782 int pnum, offset = 0;
783 unsigned long num_pages;
784 unsigned long bytes;
785
786 bytes = DIV_ROUND_UP(chunks, 8);
787 if (with_super)
788 bytes += sizeof(bitmap_super_t);
789
790 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
791 offset = slot_number * num_pages;
792
793 store->filemap = kmalloc_array(num_pages, sizeof(struct page *),
794 GFP_KERNEL);
795 if (!store->filemap)
796 return -ENOMEM;
797
798 if (with_super && !store->sb_page) {
799 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
800 if (store->sb_page == NULL)
801 return -ENOMEM;
802 }
803
804 pnum = 0;
805 if (store->sb_page) {
806 store->filemap[0] = store->sb_page;
807 pnum = 1;
808 store->sb_page->index = offset;
809 }
810
811 for ( ; pnum < num_pages; pnum++) {
812 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
813 if (!store->filemap[pnum]) {
814 store->file_pages = pnum;
815 return -ENOMEM;
816 }
817 store->filemap[pnum]->index = pnum + offset;
818 }
819 store->file_pages = pnum;
820
821 /* We need 4 bits per page, rounded up to a multiple
822 * of sizeof(unsigned long) */
823 store->filemap_attr = kzalloc(
824 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
825 GFP_KERNEL);
826 if (!store->filemap_attr)
827 return -ENOMEM;
828
829 store->bytes = bytes;
830
831 return 0;
832}
833
834static void md_bitmap_file_unmap(struct bitmap_storage *store)
835{
836 struct page **map, *sb_page;
837 int pages;
838 struct file *file;
839
840 file = store->file;
841 map = store->filemap;
842 pages = store->file_pages;
843 sb_page = store->sb_page;
844
845 while (pages--)
846 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
847 free_buffers(map[pages]);
848 kfree(map);
849 kfree(store->filemap_attr);
850
851 if (sb_page)
852 free_buffers(sb_page);
853
854 if (file) {
855 struct inode *inode = file_inode(file);
856 invalidate_mapping_pages(inode->i_mapping, 0, -1);
857 fput(file);
858 }
859}
860
861/*
862 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
863 * then it is no longer reliable, so we stop using it and we mark the file
864 * as failed in the superblock
865 */
866static void md_bitmap_file_kick(struct bitmap *bitmap)
867{
868 char *path, *ptr = NULL;
869
870 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
871 md_bitmap_update_sb(bitmap);
872
873 if (bitmap->storage.file) {
874 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
875 if (path)
876 ptr = file_path(bitmap->storage.file,
877 path, PAGE_SIZE);
878
879 pr_warn("%s: kicking failed bitmap file %s from array!\n",
880 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
881
882 kfree(path);
883 } else
884 pr_warn("%s: disabling internal bitmap due to errors\n",
885 bmname(bitmap));
886 }
887}
888
889enum bitmap_page_attr {
890 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
891 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
892 * i.e. counter is 1 or 2. */
893 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
894};
895
896static inline void set_page_attr(struct bitmap *bitmap, int pnum,
897 enum bitmap_page_attr attr)
898{
899 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
900}
901
902static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
903 enum bitmap_page_attr attr)
904{
905 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
906}
907
908static inline int test_page_attr(struct bitmap *bitmap, int pnum,
909 enum bitmap_page_attr attr)
910{
911 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
912}
913
914static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
915 enum bitmap_page_attr attr)
916{
917 return test_and_clear_bit((pnum<<2) + attr,
918 bitmap->storage.filemap_attr);
919}
920/*
921 * bitmap_file_set_bit -- called before performing a write to the md device
922 * to set (and eventually sync) a particular bit in the bitmap file
923 *
924 * we set the bit immediately, then we record the page number so that
925 * when an unplug occurs, we can flush the dirty pages out to disk
926 */
927static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
928{
929 unsigned long bit;
930 struct page *page;
931 void *kaddr;
932 unsigned long chunk = block >> bitmap->counts.chunkshift;
933 struct bitmap_storage *store = &bitmap->storage;
934 unsigned long node_offset = 0;
935
936 if (mddev_is_clustered(bitmap->mddev))
937 node_offset = bitmap->cluster_slot * store->file_pages;
938
939 page = filemap_get_page(&bitmap->storage, chunk);
940 if (!page)
941 return;
942 bit = file_page_offset(&bitmap->storage, chunk);
943
944 /* set the bit */
945 kaddr = kmap_atomic(page);
946 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
947 set_bit(bit, kaddr);
948 else
949 set_bit_le(bit, kaddr);
950 kunmap_atomic(kaddr);
951 pr_debug("set file bit %lu page %lu\n", bit, page->index);
952 /* record page number so it gets flushed to disk when unplug occurs */
953 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_DIRTY);
954}
955
956static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
957{
958 unsigned long bit;
959 struct page *page;
960 void *paddr;
961 unsigned long chunk = block >> bitmap->counts.chunkshift;
962 struct bitmap_storage *store = &bitmap->storage;
963 unsigned long node_offset = 0;
964
965 if (mddev_is_clustered(bitmap->mddev))
966 node_offset = bitmap->cluster_slot * store->file_pages;
967
968 page = filemap_get_page(&bitmap->storage, chunk);
969 if (!page)
970 return;
971 bit = file_page_offset(&bitmap->storage, chunk);
972 paddr = kmap_atomic(page);
973 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
974 clear_bit(bit, paddr);
975 else
976 clear_bit_le(bit, paddr);
977 kunmap_atomic(paddr);
978 if (!test_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
979 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_PENDING);
980 bitmap->allclean = 0;
981 }
982}
983
984static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
985{
986 unsigned long bit;
987 struct page *page;
988 void *paddr;
989 unsigned long chunk = block >> bitmap->counts.chunkshift;
990 int set = 0;
991
992 page = filemap_get_page(&bitmap->storage, chunk);
993 if (!page)
994 return -EINVAL;
995 bit = file_page_offset(&bitmap->storage, chunk);
996 paddr = kmap_atomic(page);
997 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
998 set = test_bit(bit, paddr);
999 else
1000 set = test_bit_le(bit, paddr);
1001 kunmap_atomic(paddr);
1002 return set;
1003}
1004
1005
1006/* this gets called when the md device is ready to unplug its underlying
1007 * (slave) device queues -- before we let any writes go down, we need to
1008 * sync the dirty pages of the bitmap file to disk */
1009void md_bitmap_unplug(struct bitmap *bitmap)
1010{
1011 unsigned long i;
1012 int dirty, need_write;
1013 int writing = 0;
1014
1015 if (!bitmap || !bitmap->storage.filemap ||
1016 test_bit(BITMAP_STALE, &bitmap->flags))
1017 return;
1018
1019 /* look at each page to see if there are any set bits that need to be
1020 * flushed out to disk */
1021 for (i = 0; i < bitmap->storage.file_pages; i++) {
1022 if (!bitmap->storage.filemap)
1023 return;
1024 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1025 need_write = test_and_clear_page_attr(bitmap, i,
1026 BITMAP_PAGE_NEEDWRITE);
1027 if (dirty || need_write) {
1028 if (!writing) {
1029 md_bitmap_wait_writes(bitmap);
1030 if (bitmap->mddev->queue)
1031 blk_add_trace_msg(bitmap->mddev->queue,
1032 "md bitmap_unplug");
1033 }
1034 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
1035 write_page(bitmap, bitmap->storage.filemap[i], 0);
1036 writing = 1;
1037 }
1038 }
1039 if (writing)
1040 md_bitmap_wait_writes(bitmap);
1041
1042 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1043 md_bitmap_file_kick(bitmap);
1044}
1045EXPORT_SYMBOL(md_bitmap_unplug);
1046
1047static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1048/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
1049 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
1050 * memory mapping of the bitmap file
1051 * Special cases:
1052 * if there's no bitmap file, or if the bitmap file had been
1053 * previously kicked from the array, we mark all the bits as
1054 * 1's in order to cause a full resync.
1055 *
1056 * We ignore all bits for sectors that end earlier than 'start'.
1057 * This is used when reading an out-of-date bitmap...
1058 */
1059static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1060{
1061 unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
1062 struct page *page = NULL;
1063 unsigned long bit_cnt = 0;
1064 struct file *file;
1065 unsigned long offset;
1066 int outofdate;
1067 int ret = -ENOSPC;
1068 void *paddr;
1069 struct bitmap_storage *store = &bitmap->storage;
1070
1071 chunks = bitmap->counts.chunks;
1072 file = store->file;
1073
1074 if (!file && !bitmap->mddev->bitmap_info.offset) {
1075 /* No permanent bitmap - fill with '1s'. */
1076 store->filemap = NULL;
1077 store->file_pages = 0;
1078 for (i = 0; i < chunks ; i++) {
1079 /* if the disk bit is set, set the memory bit */
1080 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1081 >= start);
1082 md_bitmap_set_memory_bits(bitmap,
1083 (sector_t)i << bitmap->counts.chunkshift,
1084 needed);
1085 }
1086 return 0;
1087 }
1088
1089 outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1090 if (outofdate)
1091 pr_warn("%s: bitmap file is out of date, doing full recovery\n", bmname(bitmap));
1092
1093 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
1094 pr_warn("%s: bitmap file too short %lu < %lu\n",
1095 bmname(bitmap),
1096 (unsigned long) i_size_read(file->f_mapping->host),
1097 store->bytes);
1098 goto err;
1099 }
1100
1101 oldindex = ~0L;
1102 offset = 0;
1103 if (!bitmap->mddev->bitmap_info.external)
1104 offset = sizeof(bitmap_super_t);
1105
1106 if (mddev_is_clustered(bitmap->mddev))
1107 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1108
1109 for (i = 0; i < chunks; i++) {
1110 int b;
1111 index = file_page_index(&bitmap->storage, i);
1112 bit = file_page_offset(&bitmap->storage, i);
1113 if (index != oldindex) { /* this is a new page, read it in */
1114 int count;
1115 /* unmap the old page, we're done with it */
1116 if (index == store->file_pages-1)
1117 count = store->bytes - index * PAGE_SIZE;
1118 else
1119 count = PAGE_SIZE;
1120 page = store->filemap[index];
1121 if (file)
1122 ret = read_page(file, index, bitmap,
1123 count, page);
1124 else
1125 ret = read_sb_page(
1126 bitmap->mddev,
1127 bitmap->mddev->bitmap_info.offset,
1128 page,
1129 index + node_offset, count);
1130
1131 if (ret)
1132 goto err;
1133
1134 oldindex = index;
1135
1136 if (outofdate) {
1137 /*
1138 * if bitmap is out of date, dirty the
1139 * whole page and write it out
1140 */
1141 paddr = kmap_atomic(page);
1142 memset(paddr + offset, 0xff,
1143 PAGE_SIZE - offset);
1144 kunmap_atomic(paddr);
1145 write_page(bitmap, page, 1);
1146
1147 ret = -EIO;
1148 if (test_bit(BITMAP_WRITE_ERROR,
1149 &bitmap->flags))
1150 goto err;
1151 }
1152 }
1153 paddr = kmap_atomic(page);
1154 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1155 b = test_bit(bit, paddr);
1156 else
1157 b = test_bit_le(bit, paddr);
1158 kunmap_atomic(paddr);
1159 if (b) {
1160 /* if the disk bit is set, set the memory bit */
1161 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1162 >= start);
1163 md_bitmap_set_memory_bits(bitmap,
1164 (sector_t)i << bitmap->counts.chunkshift,
1165 needed);
1166 bit_cnt++;
1167 }
1168 offset = 0;
1169 }
1170
1171 pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
1172 bmname(bitmap), store->file_pages,
1173 bit_cnt, chunks);
1174
1175 return 0;
1176
1177 err:
1178 pr_warn("%s: bitmap initialisation failed: %d\n",
1179 bmname(bitmap), ret);
1180 return ret;
1181}
1182
1183void md_bitmap_write_all(struct bitmap *bitmap)
1184{
1185 /* We don't actually write all bitmap blocks here,
1186 * just flag them as needing to be written
1187 */
1188 int i;
1189
1190 if (!bitmap || !bitmap->storage.filemap)
1191 return;
1192 if (bitmap->storage.file)
1193 /* Only one copy, so nothing needed */
1194 return;
1195
1196 for (i = 0; i < bitmap->storage.file_pages; i++)
1197 set_page_attr(bitmap, i,
1198 BITMAP_PAGE_NEEDWRITE);
1199 bitmap->allclean = 0;
1200}
1201
1202static void md_bitmap_count_page(struct bitmap_counts *bitmap,
1203 sector_t offset, int inc)
1204{
1205 sector_t chunk = offset >> bitmap->chunkshift;
1206 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1207 bitmap->bp[page].count += inc;
1208 md_bitmap_checkfree(bitmap, page);
1209}
1210
1211static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1212{
1213 sector_t chunk = offset >> bitmap->chunkshift;
1214 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1215 struct bitmap_page *bp = &bitmap->bp[page];
1216
1217 if (!bp->pending)
1218 bp->pending = 1;
1219}
1220
1221static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1222 sector_t offset, sector_t *blocks,
1223 int create);
1224
1225/*
1226 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1227 * out to disk
1228 */
1229
1230void md_bitmap_daemon_work(struct mddev *mddev)
1231{
1232 struct bitmap *bitmap;
1233 unsigned long j;
1234 unsigned long nextpage;
1235 sector_t blocks;
1236 struct bitmap_counts *counts;
1237
1238 /* Use a mutex to guard daemon_work against
1239 * bitmap_destroy.
1240 */
1241 mutex_lock(&mddev->bitmap_info.mutex);
1242 bitmap = mddev->bitmap;
1243 if (bitmap == NULL) {
1244 mutex_unlock(&mddev->bitmap_info.mutex);
1245 return;
1246 }
1247 if (time_before(jiffies, bitmap->daemon_lastrun
1248 + mddev->bitmap_info.daemon_sleep))
1249 goto done;
1250
1251 bitmap->daemon_lastrun = jiffies;
1252 if (bitmap->allclean) {
1253 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1254 goto done;
1255 }
1256 bitmap->allclean = 1;
1257
1258 if (bitmap->mddev->queue)
1259 blk_add_trace_msg(bitmap->mddev->queue,
1260 "md bitmap_daemon_work");
1261
1262 /* Any file-page which is PENDING now needs to be written.
1263 * So set NEEDWRITE now, then after we make any last-minute changes
1264 * we will write it.
1265 */
1266 for (j = 0; j < bitmap->storage.file_pages; j++)
1267 if (test_and_clear_page_attr(bitmap, j,
1268 BITMAP_PAGE_PENDING))
1269 set_page_attr(bitmap, j,
1270 BITMAP_PAGE_NEEDWRITE);
1271
1272 if (bitmap->need_sync &&
1273 mddev->bitmap_info.external == 0) {
1274 /* Arrange for superblock update as well as
1275 * other changes */
1276 bitmap_super_t *sb;
1277 bitmap->need_sync = 0;
1278 if (bitmap->storage.filemap) {
1279 sb = kmap_atomic(bitmap->storage.sb_page);
1280 sb->events_cleared =
1281 cpu_to_le64(bitmap->events_cleared);
1282 kunmap_atomic(sb);
1283 set_page_attr(bitmap, 0,
1284 BITMAP_PAGE_NEEDWRITE);
1285 }
1286 }
1287 /* Now look at the bitmap counters and if any are '2' or '1',
1288 * decrement and handle accordingly.
1289 */
1290 counts = &bitmap->counts;
1291 spin_lock_irq(&counts->lock);
1292 nextpage = 0;
1293 for (j = 0; j < counts->chunks; j++) {
1294 bitmap_counter_t *bmc;
1295 sector_t block = (sector_t)j << counts->chunkshift;
1296
1297 if (j == nextpage) {
1298 nextpage += PAGE_COUNTER_RATIO;
1299 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1300 j |= PAGE_COUNTER_MASK;
1301 continue;
1302 }
1303 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1304 }
1305
1306 bmc = md_bitmap_get_counter(counts, block, &blocks, 0);
1307 if (!bmc) {
1308 j |= PAGE_COUNTER_MASK;
1309 continue;
1310 }
1311 if (*bmc == 1 && !bitmap->need_sync) {
1312 /* We can clear the bit */
1313 *bmc = 0;
1314 md_bitmap_count_page(counts, block, -1);
1315 md_bitmap_file_clear_bit(bitmap, block);
1316 } else if (*bmc && *bmc <= 2) {
1317 *bmc = 1;
1318 md_bitmap_set_pending(counts, block);
1319 bitmap->allclean = 0;
1320 }
1321 }
1322 spin_unlock_irq(&counts->lock);
1323
1324 md_bitmap_wait_writes(bitmap);
1325 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1326 * DIRTY pages need to be written by bitmap_unplug so it can wait
1327 * for them.
1328 * If we find any DIRTY page we stop there and let bitmap_unplug
1329 * handle all the rest. This is important in the case where
1330 * the first blocking holds the superblock and it has been updated.
1331 * We mustn't write any other blocks before the superblock.
1332 */
1333 for (j = 0;
1334 j < bitmap->storage.file_pages
1335 && !test_bit(BITMAP_STALE, &bitmap->flags);
1336 j++) {
1337 if (test_page_attr(bitmap, j,
1338 BITMAP_PAGE_DIRTY))
1339 /* bitmap_unplug will handle the rest */
1340 break;
1341 if (test_and_clear_page_attr(bitmap, j,
1342 BITMAP_PAGE_NEEDWRITE)) {
1343 write_page(bitmap, bitmap->storage.filemap[j], 0);
1344 }
1345 }
1346
1347 done:
1348 if (bitmap->allclean == 0)
1349 mddev->thread->timeout =
1350 mddev->bitmap_info.daemon_sleep;
1351 mutex_unlock(&mddev->bitmap_info.mutex);
1352}
1353
1354static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1355 sector_t offset, sector_t *blocks,
1356 int create)
1357__releases(bitmap->lock)
1358__acquires(bitmap->lock)
1359{
1360 /* If 'create', we might release the lock and reclaim it.
1361 * The lock must have been taken with interrupts enabled.
1362 * If !create, we don't release the lock.
1363 */
1364 sector_t chunk = offset >> bitmap->chunkshift;
1365 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1366 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1367 sector_t csize;
1368 int err;
1369
1370 err = md_bitmap_checkpage(bitmap, page, create, 0);
1371
1372 if (bitmap->bp[page].hijacked ||
1373 bitmap->bp[page].map == NULL)
1374 csize = ((sector_t)1) << (bitmap->chunkshift +
1375 PAGE_COUNTER_SHIFT - 1);
1376 else
1377 csize = ((sector_t)1) << bitmap->chunkshift;
1378 *blocks = csize - (offset & (csize - 1));
1379
1380 if (err < 0)
1381 return NULL;
1382
1383 /* now locked ... */
1384
1385 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1386 /* should we use the first or second counter field
1387 * of the hijacked pointer? */
1388 int hi = (pageoff > PAGE_COUNTER_MASK);
1389 return &((bitmap_counter_t *)
1390 &bitmap->bp[page].map)[hi];
1391 } else /* page is allocated */
1392 return (bitmap_counter_t *)
1393 &(bitmap->bp[page].map[pageoff]);
1394}
1395
1396int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1397{
1398 if (!bitmap)
1399 return 0;
1400
1401 if (behind) {
1402 int bw;
1403 atomic_inc(&bitmap->behind_writes);
1404 bw = atomic_read(&bitmap->behind_writes);
1405 if (bw > bitmap->behind_writes_used)
1406 bitmap->behind_writes_used = bw;
1407
1408 pr_debug("inc write-behind count %d/%lu\n",
1409 bw, bitmap->mddev->bitmap_info.max_write_behind);
1410 }
1411
1412 while (sectors) {
1413 sector_t blocks;
1414 bitmap_counter_t *bmc;
1415
1416 spin_lock_irq(&bitmap->counts.lock);
1417 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1418 if (!bmc) {
1419 spin_unlock_irq(&bitmap->counts.lock);
1420 return 0;
1421 }
1422
1423 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1424 DEFINE_WAIT(__wait);
1425 /* note that it is safe to do the prepare_to_wait
1426 * after the test as long as we do it before dropping
1427 * the spinlock.
1428 */
1429 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1430 TASK_UNINTERRUPTIBLE);
1431 spin_unlock_irq(&bitmap->counts.lock);
1432 schedule();
1433 finish_wait(&bitmap->overflow_wait, &__wait);
1434 continue;
1435 }
1436
1437 switch (*bmc) {
1438 case 0:
1439 md_bitmap_file_set_bit(bitmap, offset);
1440 md_bitmap_count_page(&bitmap->counts, offset, 1);
1441 /* fall through */
1442 case 1:
1443 *bmc = 2;
1444 }
1445
1446 (*bmc)++;
1447
1448 spin_unlock_irq(&bitmap->counts.lock);
1449
1450 offset += blocks;
1451 if (sectors > blocks)
1452 sectors -= blocks;
1453 else
1454 sectors = 0;
1455 }
1456 return 0;
1457}
1458EXPORT_SYMBOL(md_bitmap_startwrite);
1459
1460void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
1461 unsigned long sectors, int success, int behind)
1462{
1463 if (!bitmap)
1464 return;
1465 if (behind) {
1466 if (atomic_dec_and_test(&bitmap->behind_writes))
1467 wake_up(&bitmap->behind_wait);
1468 pr_debug("dec write-behind count %d/%lu\n",
1469 atomic_read(&bitmap->behind_writes),
1470 bitmap->mddev->bitmap_info.max_write_behind);
1471 }
1472
1473 while (sectors) {
1474 sector_t blocks;
1475 unsigned long flags;
1476 bitmap_counter_t *bmc;
1477
1478 spin_lock_irqsave(&bitmap->counts.lock, flags);
1479 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1480 if (!bmc) {
1481 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1482 return;
1483 }
1484
1485 if (success && !bitmap->mddev->degraded &&
1486 bitmap->events_cleared < bitmap->mddev->events) {
1487 bitmap->events_cleared = bitmap->mddev->events;
1488 bitmap->need_sync = 1;
1489 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1490 }
1491
1492 if (!success && !NEEDED(*bmc))
1493 *bmc |= NEEDED_MASK;
1494
1495 if (COUNTER(*bmc) == COUNTER_MAX)
1496 wake_up(&bitmap->overflow_wait);
1497
1498 (*bmc)--;
1499 if (*bmc <= 2) {
1500 md_bitmap_set_pending(&bitmap->counts, offset);
1501 bitmap->allclean = 0;
1502 }
1503 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1504 offset += blocks;
1505 if (sectors > blocks)
1506 sectors -= blocks;
1507 else
1508 sectors = 0;
1509 }
1510}
1511EXPORT_SYMBOL(md_bitmap_endwrite);
1512
1513static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1514 int degraded)
1515{
1516 bitmap_counter_t *bmc;
1517 int rv;
1518 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1519 *blocks = 1024;
1520 return 1; /* always resync if no bitmap */
1521 }
1522 spin_lock_irq(&bitmap->counts.lock);
1523 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1524 rv = 0;
1525 if (bmc) {
1526 /* locked */
1527 if (RESYNC(*bmc))
1528 rv = 1;
1529 else if (NEEDED(*bmc)) {
1530 rv = 1;
1531 if (!degraded) { /* don't set/clear bits if degraded */
1532 *bmc |= RESYNC_MASK;
1533 *bmc &= ~NEEDED_MASK;
1534 }
1535 }
1536 }
1537 spin_unlock_irq(&bitmap->counts.lock);
1538 return rv;
1539}
1540
1541int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1542 int degraded)
1543{
1544 /* bitmap_start_sync must always report on multiples of whole
1545 * pages, otherwise resync (which is very PAGE_SIZE based) will
1546 * get confused.
1547 * So call __bitmap_start_sync repeatedly (if needed) until
1548 * At least PAGE_SIZE>>9 blocks are covered.
1549 * Return the 'or' of the result.
1550 */
1551 int rv = 0;
1552 sector_t blocks1;
1553
1554 *blocks = 0;
1555 while (*blocks < (PAGE_SIZE>>9)) {
1556 rv |= __bitmap_start_sync(bitmap, offset,
1557 &blocks1, degraded);
1558 offset += blocks1;
1559 *blocks += blocks1;
1560 }
1561 return rv;
1562}
1563EXPORT_SYMBOL(md_bitmap_start_sync);
1564
1565void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1566{
1567 bitmap_counter_t *bmc;
1568 unsigned long flags;
1569
1570 if (bitmap == NULL) {
1571 *blocks = 1024;
1572 return;
1573 }
1574 spin_lock_irqsave(&bitmap->counts.lock, flags);
1575 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1576 if (bmc == NULL)
1577 goto unlock;
1578 /* locked */
1579 if (RESYNC(*bmc)) {
1580 *bmc &= ~RESYNC_MASK;
1581
1582 if (!NEEDED(*bmc) && aborted)
1583 *bmc |= NEEDED_MASK;
1584 else {
1585 if (*bmc <= 2) {
1586 md_bitmap_set_pending(&bitmap->counts, offset);
1587 bitmap->allclean = 0;
1588 }
1589 }
1590 }
1591 unlock:
1592 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1593}
1594EXPORT_SYMBOL(md_bitmap_end_sync);
1595
1596void md_bitmap_close_sync(struct bitmap *bitmap)
1597{
1598 /* Sync has finished, and any bitmap chunks that weren't synced
1599 * properly have been aborted. It remains to us to clear the
1600 * RESYNC bit wherever it is still on
1601 */
1602 sector_t sector = 0;
1603 sector_t blocks;
1604 if (!bitmap)
1605 return;
1606 while (sector < bitmap->mddev->resync_max_sectors) {
1607 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1608 sector += blocks;
1609 }
1610}
1611EXPORT_SYMBOL(md_bitmap_close_sync);
1612
1613void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
1614{
1615 sector_t s = 0;
1616 sector_t blocks;
1617
1618 if (!bitmap)
1619 return;
1620 if (sector == 0) {
1621 bitmap->last_end_sync = jiffies;
1622 return;
1623 }
1624 if (!force && time_before(jiffies, (bitmap->last_end_sync
1625 + bitmap->mddev->bitmap_info.daemon_sleep)))
1626 return;
1627 wait_event(bitmap->mddev->recovery_wait,
1628 atomic_read(&bitmap->mddev->recovery_active) == 0);
1629
1630 bitmap->mddev->curr_resync_completed = sector;
1631 set_bit(MD_SB_CHANGE_CLEAN, &bitmap->mddev->sb_flags);
1632 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1633 s = 0;
1634 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1635 md_bitmap_end_sync(bitmap, s, &blocks, 0);
1636 s += blocks;
1637 }
1638 bitmap->last_end_sync = jiffies;
1639 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1640}
1641EXPORT_SYMBOL(md_bitmap_cond_end_sync);
1642
1643void md_bitmap_sync_with_cluster(struct mddev *mddev,
1644 sector_t old_lo, sector_t old_hi,
1645 sector_t new_lo, sector_t new_hi)
1646{
1647 struct bitmap *bitmap = mddev->bitmap;
1648 sector_t sector, blocks = 0;
1649
1650 for (sector = old_lo; sector < new_lo; ) {
1651 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1652 sector += blocks;
1653 }
1654 WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
1655
1656 for (sector = old_hi; sector < new_hi; ) {
1657 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1658 sector += blocks;
1659 }
1660 WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
1661}
1662EXPORT_SYMBOL(md_bitmap_sync_with_cluster);
1663
1664static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1665{
1666 /* For each chunk covered by any of these sectors, set the
1667 * counter to 2 and possibly set resync_needed. They should all
1668 * be 0 at this point
1669 */
1670
1671 sector_t secs;
1672 bitmap_counter_t *bmc;
1673 spin_lock_irq(&bitmap->counts.lock);
1674 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1675 if (!bmc) {
1676 spin_unlock_irq(&bitmap->counts.lock);
1677 return;
1678 }
1679 if (!*bmc) {
1680 *bmc = 2;
1681 md_bitmap_count_page(&bitmap->counts, offset, 1);
1682 md_bitmap_set_pending(&bitmap->counts, offset);
1683 bitmap->allclean = 0;
1684 }
1685 if (needed)
1686 *bmc |= NEEDED_MASK;
1687 spin_unlock_irq(&bitmap->counts.lock);
1688}
1689
1690/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1691void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1692{
1693 unsigned long chunk;
1694
1695 for (chunk = s; chunk <= e; chunk++) {
1696 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1697 md_bitmap_set_memory_bits(bitmap, sec, 1);
1698 md_bitmap_file_set_bit(bitmap, sec);
1699 if (sec < bitmap->mddev->recovery_cp)
1700 /* We are asserting that the array is dirty,
1701 * so move the recovery_cp address back so
1702 * that it is obvious that it is dirty
1703 */
1704 bitmap->mddev->recovery_cp = sec;
1705 }
1706}
1707
1708/*
1709 * flush out any pending updates
1710 */
1711void md_bitmap_flush(struct mddev *mddev)
1712{
1713 struct bitmap *bitmap = mddev->bitmap;
1714 long sleep;
1715
1716 if (!bitmap) /* there was no bitmap */
1717 return;
1718
1719 /* run the daemon_work three time to ensure everything is flushed
1720 * that can be
1721 */
1722 sleep = mddev->bitmap_info.daemon_sleep * 2;
1723 bitmap->daemon_lastrun -= sleep;
1724 md_bitmap_daemon_work(mddev);
1725 bitmap->daemon_lastrun -= sleep;
1726 md_bitmap_daemon_work(mddev);
1727 bitmap->daemon_lastrun -= sleep;
1728 md_bitmap_daemon_work(mddev);
1729 md_bitmap_update_sb(bitmap);
1730}
1731
1732/*
1733 * free memory that was allocated
1734 */
1735void md_bitmap_free(struct bitmap *bitmap)
1736{
1737 unsigned long k, pages;
1738 struct bitmap_page *bp;
1739
1740 if (!bitmap) /* there was no bitmap */
1741 return;
1742
1743 if (bitmap->sysfs_can_clear)
1744 sysfs_put(bitmap->sysfs_can_clear);
1745
1746 if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
1747 bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
1748 md_cluster_stop(bitmap->mddev);
1749
1750 /* Shouldn't be needed - but just in case.... */
1751 wait_event(bitmap->write_wait,
1752 atomic_read(&bitmap->pending_writes) == 0);
1753
1754 /* release the bitmap file */
1755 md_bitmap_file_unmap(&bitmap->storage);
1756
1757 bp = bitmap->counts.bp;
1758 pages = bitmap->counts.pages;
1759
1760 /* free all allocated memory */
1761
1762 if (bp) /* deallocate the page memory */
1763 for (k = 0; k < pages; k++)
1764 if (bp[k].map && !bp[k].hijacked)
1765 kfree(bp[k].map);
1766 kfree(bp);
1767 kfree(bitmap);
1768}
1769EXPORT_SYMBOL(md_bitmap_free);
1770
1771void md_bitmap_wait_behind_writes(struct mddev *mddev)
1772{
1773 struct bitmap *bitmap = mddev->bitmap;
1774
1775 /* wait for behind writes to complete */
1776 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1777 pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
1778 mdname(mddev));
1779 /* need to kick something here to make sure I/O goes? */
1780 wait_event(bitmap->behind_wait,
1781 atomic_read(&bitmap->behind_writes) == 0);
1782 }
1783}
1784
1785void md_bitmap_destroy(struct mddev *mddev)
1786{
1787 struct bitmap *bitmap = mddev->bitmap;
1788
1789 if (!bitmap) /* there was no bitmap */
1790 return;
1791
1792 md_bitmap_wait_behind_writes(mddev);
1793 mempool_destroy(mddev->wb_info_pool);
1794 mddev->wb_info_pool = NULL;
1795
1796 mutex_lock(&mddev->bitmap_info.mutex);
1797 spin_lock(&mddev->lock);
1798 mddev->bitmap = NULL; /* disconnect from the md device */
1799 spin_unlock(&mddev->lock);
1800 mutex_unlock(&mddev->bitmap_info.mutex);
1801 if (mddev->thread)
1802 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1803
1804 md_bitmap_free(bitmap);
1805}
1806
1807/*
1808 * initialize the bitmap structure
1809 * if this returns an error, bitmap_destroy must be called to do clean up
1810 * once mddev->bitmap is set
1811 */
1812struct bitmap *md_bitmap_create(struct mddev *mddev, int slot)
1813{
1814 struct bitmap *bitmap;
1815 sector_t blocks = mddev->resync_max_sectors;
1816 struct file *file = mddev->bitmap_info.file;
1817 int err;
1818 struct kernfs_node *bm = NULL;
1819
1820 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1821
1822 BUG_ON(file && mddev->bitmap_info.offset);
1823
1824 if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
1825 pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
1826 mdname(mddev));
1827 return ERR_PTR(-EBUSY);
1828 }
1829
1830 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1831 if (!bitmap)
1832 return ERR_PTR(-ENOMEM);
1833
1834 spin_lock_init(&bitmap->counts.lock);
1835 atomic_set(&bitmap->pending_writes, 0);
1836 init_waitqueue_head(&bitmap->write_wait);
1837 init_waitqueue_head(&bitmap->overflow_wait);
1838 init_waitqueue_head(&bitmap->behind_wait);
1839
1840 bitmap->mddev = mddev;
1841 bitmap->cluster_slot = slot;
1842
1843 if (mddev->kobj.sd)
1844 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
1845 if (bm) {
1846 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
1847 sysfs_put(bm);
1848 } else
1849 bitmap->sysfs_can_clear = NULL;
1850
1851 bitmap->storage.file = file;
1852 if (file) {
1853 get_file(file);
1854 /* As future accesses to this file will use bmap,
1855 * and bypass the page cache, we must sync the file
1856 * first.
1857 */
1858 vfs_fsync(file, 1);
1859 }
1860 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1861 if (!mddev->bitmap_info.external) {
1862 /*
1863 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1864 * instructing us to create a new on-disk bitmap instance.
1865 */
1866 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1867 err = md_bitmap_new_disk_sb(bitmap);
1868 else
1869 err = md_bitmap_read_sb(bitmap);
1870 } else {
1871 err = 0;
1872 if (mddev->bitmap_info.chunksize == 0 ||
1873 mddev->bitmap_info.daemon_sleep == 0)
1874 /* chunksize and time_base need to be
1875 * set first. */
1876 err = -EINVAL;
1877 }
1878 if (err)
1879 goto error;
1880
1881 bitmap->daemon_lastrun = jiffies;
1882 err = md_bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1883 if (err)
1884 goto error;
1885
1886 pr_debug("created bitmap (%lu pages) for device %s\n",
1887 bitmap->counts.pages, bmname(bitmap));
1888
1889 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1890 if (err)
1891 goto error;
1892
1893 return bitmap;
1894 error:
1895 md_bitmap_free(bitmap);
1896 return ERR_PTR(err);
1897}
1898
1899int md_bitmap_load(struct mddev *mddev)
1900{
1901 int err = 0;
1902 sector_t start = 0;
1903 sector_t sector = 0;
1904 struct bitmap *bitmap = mddev->bitmap;
1905 struct md_rdev *rdev;
1906
1907 if (!bitmap)
1908 goto out;
1909
1910 rdev_for_each(rdev, mddev)
1911 mddev_create_wb_pool(mddev, rdev, true);
1912
1913 if (mddev_is_clustered(mddev))
1914 md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
1915
1916 /* Clear out old bitmap info first: Either there is none, or we
1917 * are resuming after someone else has possibly changed things,
1918 * so we should forget old cached info.
1919 * All chunks should be clean, but some might need_sync.
1920 */
1921 while (sector < mddev->resync_max_sectors) {
1922 sector_t blocks;
1923 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1924 sector += blocks;
1925 }
1926 md_bitmap_close_sync(bitmap);
1927
1928 if (mddev->degraded == 0
1929 || bitmap->events_cleared == mddev->events)
1930 /* no need to keep dirty bits to optimise a
1931 * re-add of a missing device */
1932 start = mddev->recovery_cp;
1933
1934 mutex_lock(&mddev->bitmap_info.mutex);
1935 err = md_bitmap_init_from_disk(bitmap, start);
1936 mutex_unlock(&mddev->bitmap_info.mutex);
1937
1938 if (err)
1939 goto out;
1940 clear_bit(BITMAP_STALE, &bitmap->flags);
1941
1942 /* Kick recovery in case any bits were set */
1943 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1944
1945 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1946 md_wakeup_thread(mddev->thread);
1947
1948 md_bitmap_update_sb(bitmap);
1949
1950 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1951 err = -EIO;
1952out:
1953 return err;
1954}
1955EXPORT_SYMBOL_GPL(md_bitmap_load);
1956
1957struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
1958{
1959 int rv = 0;
1960 struct bitmap *bitmap;
1961
1962 bitmap = md_bitmap_create(mddev, slot);
1963 if (IS_ERR(bitmap)) {
1964 rv = PTR_ERR(bitmap);
1965 return ERR_PTR(rv);
1966 }
1967
1968 rv = md_bitmap_init_from_disk(bitmap, 0);
1969 if (rv) {
1970 md_bitmap_free(bitmap);
1971 return ERR_PTR(rv);
1972 }
1973
1974 return bitmap;
1975}
1976EXPORT_SYMBOL(get_bitmap_from_slot);
1977
1978/* Loads the bitmap associated with slot and copies the resync information
1979 * to our bitmap
1980 */
1981int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
1982 sector_t *low, sector_t *high, bool clear_bits)
1983{
1984 int rv = 0, i, j;
1985 sector_t block, lo = 0, hi = 0;
1986 struct bitmap_counts *counts;
1987 struct bitmap *bitmap;
1988
1989 bitmap = get_bitmap_from_slot(mddev, slot);
1990 if (IS_ERR(bitmap)) {
1991 pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
1992 return -1;
1993 }
1994
1995 counts = &bitmap->counts;
1996 for (j = 0; j < counts->chunks; j++) {
1997 block = (sector_t)j << counts->chunkshift;
1998 if (md_bitmap_file_test_bit(bitmap, block)) {
1999 if (!lo)
2000 lo = block;
2001 hi = block;
2002 md_bitmap_file_clear_bit(bitmap, block);
2003 md_bitmap_set_memory_bits(mddev->bitmap, block, 1);
2004 md_bitmap_file_set_bit(mddev->bitmap, block);
2005 }
2006 }
2007
2008 if (clear_bits) {
2009 md_bitmap_update_sb(bitmap);
2010 /* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
2011 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
2012 for (i = 0; i < bitmap->storage.file_pages; i++)
2013 if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
2014 set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
2015 md_bitmap_unplug(bitmap);
2016 }
2017 md_bitmap_unplug(mddev->bitmap);
2018 *low = lo;
2019 *high = hi;
2020
2021 return rv;
2022}
2023EXPORT_SYMBOL_GPL(md_bitmap_copy_from_slot);
2024
2025
2026void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
2027{
2028 unsigned long chunk_kb;
2029 struct bitmap_counts *counts;
2030
2031 if (!bitmap)
2032 return;
2033
2034 counts = &bitmap->counts;
2035
2036 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
2037 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
2038 "%lu%s chunk",
2039 counts->pages - counts->missing_pages,
2040 counts->pages,
2041 (counts->pages - counts->missing_pages)
2042 << (PAGE_SHIFT - 10),
2043 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
2044 chunk_kb ? "KB" : "B");
2045 if (bitmap->storage.file) {
2046 seq_printf(seq, ", file: ");
2047 seq_file_path(seq, bitmap->storage.file, " \t\n");
2048 }
2049
2050 seq_printf(seq, "\n");
2051}
2052
2053int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
2054 int chunksize, int init)
2055{
2056 /* If chunk_size is 0, choose an appropriate chunk size.
2057 * Then possibly allocate new storage space.
2058 * Then quiesce, copy bits, replace bitmap, and re-start
2059 *
2060 * This function is called both to set up the initial bitmap
2061 * and to resize the bitmap while the array is active.
2062 * If this happens as a result of the array being resized,
2063 * chunksize will be zero, and we need to choose a suitable
2064 * chunksize, otherwise we use what we are given.
2065 */
2066 struct bitmap_storage store;
2067 struct bitmap_counts old_counts;
2068 unsigned long chunks;
2069 sector_t block;
2070 sector_t old_blocks, new_blocks;
2071 int chunkshift;
2072 int ret = 0;
2073 long pages;
2074 struct bitmap_page *new_bp;
2075
2076 if (bitmap->storage.file && !init) {
2077 pr_info("md: cannot resize file-based bitmap\n");
2078 return -EINVAL;
2079 }
2080
2081 if (chunksize == 0) {
2082 /* If there is enough space, leave the chunk size unchanged,
2083 * else increase by factor of two until there is enough space.
2084 */
2085 long bytes;
2086 long space = bitmap->mddev->bitmap_info.space;
2087
2088 if (space == 0) {
2089 /* We don't know how much space there is, so limit
2090 * to current size - in sectors.
2091 */
2092 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
2093 if (!bitmap->mddev->bitmap_info.external)
2094 bytes += sizeof(bitmap_super_t);
2095 space = DIV_ROUND_UP(bytes, 512);
2096 bitmap->mddev->bitmap_info.space = space;
2097 }
2098 chunkshift = bitmap->counts.chunkshift;
2099 chunkshift--;
2100 do {
2101 /* 'chunkshift' is shift from block size to chunk size */
2102 chunkshift++;
2103 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2104 bytes = DIV_ROUND_UP(chunks, 8);
2105 if (!bitmap->mddev->bitmap_info.external)
2106 bytes += sizeof(bitmap_super_t);
2107 } while (bytes > (space << 9));
2108 } else
2109 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
2110
2111 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2112 memset(&store, 0, sizeof(store));
2113 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2114 ret = md_bitmap_storage_alloc(&store, chunks,
2115 !bitmap->mddev->bitmap_info.external,
2116 mddev_is_clustered(bitmap->mddev)
2117 ? bitmap->cluster_slot : 0);
2118 if (ret) {
2119 md_bitmap_file_unmap(&store);
2120 goto err;
2121 }
2122
2123 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2124
2125 new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
2126 ret = -ENOMEM;
2127 if (!new_bp) {
2128 md_bitmap_file_unmap(&store);
2129 goto err;
2130 }
2131
2132 if (!init)
2133 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2134
2135 store.file = bitmap->storage.file;
2136 bitmap->storage.file = NULL;
2137
2138 if (store.sb_page && bitmap->storage.sb_page)
2139 memcpy(page_address(store.sb_page),
2140 page_address(bitmap->storage.sb_page),
2141 sizeof(bitmap_super_t));
2142 md_bitmap_file_unmap(&bitmap->storage);
2143 bitmap->storage = store;
2144
2145 old_counts = bitmap->counts;
2146 bitmap->counts.bp = new_bp;
2147 bitmap->counts.pages = pages;
2148 bitmap->counts.missing_pages = pages;
2149 bitmap->counts.chunkshift = chunkshift;
2150 bitmap->counts.chunks = chunks;
2151 bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift +
2152 BITMAP_BLOCK_SHIFT);
2153
2154 blocks = min(old_counts.chunks << old_counts.chunkshift,
2155 chunks << chunkshift);
2156
2157 spin_lock_irq(&bitmap->counts.lock);
2158 /* For cluster raid, need to pre-allocate bitmap */
2159 if (mddev_is_clustered(bitmap->mddev)) {
2160 unsigned long page;
2161 for (page = 0; page < pages; page++) {
2162 ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1);
2163 if (ret) {
2164 unsigned long k;
2165
2166 /* deallocate the page memory */
2167 for (k = 0; k < page; k++) {
2168 kfree(new_bp[k].map);
2169 }
2170 kfree(new_bp);
2171
2172 /* restore some fields from old_counts */
2173 bitmap->counts.bp = old_counts.bp;
2174 bitmap->counts.pages = old_counts.pages;
2175 bitmap->counts.missing_pages = old_counts.pages;
2176 bitmap->counts.chunkshift = old_counts.chunkshift;
2177 bitmap->counts.chunks = old_counts.chunks;
2178 bitmap->mddev->bitmap_info.chunksize = 1 << (old_counts.chunkshift +
2179 BITMAP_BLOCK_SHIFT);
2180 blocks = old_counts.chunks << old_counts.chunkshift;
2181 pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
2182 break;
2183 } else
2184 bitmap->counts.bp[page].count += 1;
2185 }
2186 }
2187
2188 for (block = 0; block < blocks; ) {
2189 bitmap_counter_t *bmc_old, *bmc_new;
2190 int set;
2191
2192 bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0);
2193 set = bmc_old && NEEDED(*bmc_old);
2194
2195 if (set) {
2196 bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2197 if (*bmc_new == 0) {
2198 /* need to set on-disk bits too. */
2199 sector_t end = block + new_blocks;
2200 sector_t start = block >> chunkshift;
2201 start <<= chunkshift;
2202 while (start < end) {
2203 md_bitmap_file_set_bit(bitmap, block);
2204 start += 1 << chunkshift;
2205 }
2206 *bmc_new = 2;
2207 md_bitmap_count_page(&bitmap->counts, block, 1);
2208 md_bitmap_set_pending(&bitmap->counts, block);
2209 }
2210 *bmc_new |= NEEDED_MASK;
2211 if (new_blocks < old_blocks)
2212 old_blocks = new_blocks;
2213 }
2214 block += old_blocks;
2215 }
2216
2217 if (bitmap->counts.bp != old_counts.bp) {
2218 unsigned long k;
2219 for (k = 0; k < old_counts.pages; k++)
2220 if (!old_counts.bp[k].hijacked)
2221 kfree(old_counts.bp[k].map);
2222 kfree(old_counts.bp);
2223 }
2224
2225 if (!init) {
2226 int i;
2227 while (block < (chunks << chunkshift)) {
2228 bitmap_counter_t *bmc;
2229 bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2230 if (bmc) {
2231 /* new space. It needs to be resynced, so
2232 * we set NEEDED_MASK.
2233 */
2234 if (*bmc == 0) {
2235 *bmc = NEEDED_MASK | 2;
2236 md_bitmap_count_page(&bitmap->counts, block, 1);
2237 md_bitmap_set_pending(&bitmap->counts, block);
2238 }
2239 }
2240 block += new_blocks;
2241 }
2242 for (i = 0; i < bitmap->storage.file_pages; i++)
2243 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
2244 }
2245 spin_unlock_irq(&bitmap->counts.lock);
2246
2247 if (!init) {
2248 md_bitmap_unplug(bitmap);
2249 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2250 }
2251 ret = 0;
2252err:
2253 return ret;
2254}
2255EXPORT_SYMBOL_GPL(md_bitmap_resize);
2256
2257static ssize_t
2258location_show(struct mddev *mddev, char *page)
2259{
2260 ssize_t len;
2261 if (mddev->bitmap_info.file)
2262 len = sprintf(page, "file");
2263 else if (mddev->bitmap_info.offset)
2264 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
2265 else
2266 len = sprintf(page, "none");
2267 len += sprintf(page+len, "\n");
2268 return len;
2269}
2270
2271static ssize_t
2272location_store(struct mddev *mddev, const char *buf, size_t len)
2273{
2274 int rv;
2275
2276 rv = mddev_lock(mddev);
2277 if (rv)
2278 return rv;
2279 if (mddev->pers) {
2280 if (!mddev->pers->quiesce) {
2281 rv = -EBUSY;
2282 goto out;
2283 }
2284 if (mddev->recovery || mddev->sync_thread) {
2285 rv = -EBUSY;
2286 goto out;
2287 }
2288 }
2289
2290 if (mddev->bitmap || mddev->bitmap_info.file ||
2291 mddev->bitmap_info.offset) {
2292 /* bitmap already configured. Only option is to clear it */
2293 if (strncmp(buf, "none", 4) != 0) {
2294 rv = -EBUSY;
2295 goto out;
2296 }
2297 if (mddev->pers) {
2298 mddev_suspend(mddev);
2299 md_bitmap_destroy(mddev);
2300 mddev_resume(mddev);
2301 }
2302 mddev->bitmap_info.offset = 0;
2303 if (mddev->bitmap_info.file) {
2304 struct file *f = mddev->bitmap_info.file;
2305 mddev->bitmap_info.file = NULL;
2306 fput(f);
2307 }
2308 } else {
2309 /* No bitmap, OK to set a location */
2310 long long offset;
2311 if (strncmp(buf, "none", 4) == 0)
2312 /* nothing to be done */;
2313 else if (strncmp(buf, "file:", 5) == 0) {
2314 /* Not supported yet */
2315 rv = -EINVAL;
2316 goto out;
2317 } else {
2318 if (buf[0] == '+')
2319 rv = kstrtoll(buf+1, 10, &offset);
2320 else
2321 rv = kstrtoll(buf, 10, &offset);
2322 if (rv)
2323 goto out;
2324 if (offset == 0) {
2325 rv = -EINVAL;
2326 goto out;
2327 }
2328 if (mddev->bitmap_info.external == 0 &&
2329 mddev->major_version == 0 &&
2330 offset != mddev->bitmap_info.default_offset) {
2331 rv = -EINVAL;
2332 goto out;
2333 }
2334 mddev->bitmap_info.offset = offset;
2335 if (mddev->pers) {
2336 struct bitmap *bitmap;
2337 bitmap = md_bitmap_create(mddev, -1);
2338 mddev_suspend(mddev);
2339 if (IS_ERR(bitmap))
2340 rv = PTR_ERR(bitmap);
2341 else {
2342 mddev->bitmap = bitmap;
2343 rv = md_bitmap_load(mddev);
2344 if (rv)
2345 mddev->bitmap_info.offset = 0;
2346 }
2347 if (rv) {
2348 md_bitmap_destroy(mddev);
2349 mddev_resume(mddev);
2350 goto out;
2351 }
2352 mddev_resume(mddev);
2353 }
2354 }
2355 }
2356 if (!mddev->external) {
2357 /* Ensure new bitmap info is stored in
2358 * metadata promptly.
2359 */
2360 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2361 md_wakeup_thread(mddev->thread);
2362 }
2363 rv = 0;
2364out:
2365 mddev_unlock(mddev);
2366 if (rv)
2367 return rv;
2368 return len;
2369}
2370
2371static struct md_sysfs_entry bitmap_location =
2372__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2373
2374/* 'bitmap/space' is the space available at 'location' for the
2375 * bitmap. This allows the kernel to know when it is safe to
2376 * resize the bitmap to match a resized array.
2377 */
2378static ssize_t
2379space_show(struct mddev *mddev, char *page)
2380{
2381 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2382}
2383
2384static ssize_t
2385space_store(struct mddev *mddev, const char *buf, size_t len)
2386{
2387 unsigned long sectors;
2388 int rv;
2389
2390 rv = kstrtoul(buf, 10, §ors);
2391 if (rv)
2392 return rv;
2393
2394 if (sectors == 0)
2395 return -EINVAL;
2396
2397 if (mddev->bitmap &&
2398 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2399 return -EFBIG; /* Bitmap is too big for this small space */
2400
2401 /* could make sure it isn't too big, but that isn't really
2402 * needed - user-space should be careful.
2403 */
2404 mddev->bitmap_info.space = sectors;
2405 return len;
2406}
2407
2408static struct md_sysfs_entry bitmap_space =
2409__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2410
2411static ssize_t
2412timeout_show(struct mddev *mddev, char *page)
2413{
2414 ssize_t len;
2415 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2416 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2417
2418 len = sprintf(page, "%lu", secs);
2419 if (jifs)
2420 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2421 len += sprintf(page+len, "\n");
2422 return len;
2423}
2424
2425static ssize_t
2426timeout_store(struct mddev *mddev, const char *buf, size_t len)
2427{
2428 /* timeout can be set at any time */
2429 unsigned long timeout;
2430 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2431 if (rv)
2432 return rv;
2433
2434 /* just to make sure we don't overflow... */
2435 if (timeout >= LONG_MAX / HZ)
2436 return -EINVAL;
2437
2438 timeout = timeout * HZ / 10000;
2439
2440 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2441 timeout = MAX_SCHEDULE_TIMEOUT-1;
2442 if (timeout < 1)
2443 timeout = 1;
2444 mddev->bitmap_info.daemon_sleep = timeout;
2445 if (mddev->thread) {
2446 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
2447 * the bitmap is all clean and we don't need to
2448 * adjust the timeout right now
2449 */
2450 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2451 mddev->thread->timeout = timeout;
2452 md_wakeup_thread(mddev->thread);
2453 }
2454 }
2455 return len;
2456}
2457
2458static struct md_sysfs_entry bitmap_timeout =
2459__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2460
2461static ssize_t
2462backlog_show(struct mddev *mddev, char *page)
2463{
2464 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2465}
2466
2467static ssize_t
2468backlog_store(struct mddev *mddev, const char *buf, size_t len)
2469{
2470 unsigned long backlog;
2471 unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
2472 int rv = kstrtoul(buf, 10, &backlog);
2473 if (rv)
2474 return rv;
2475 if (backlog > COUNTER_MAX)
2476 return -EINVAL;
2477 mddev->bitmap_info.max_write_behind = backlog;
2478 if (!backlog && mddev->wb_info_pool) {
2479 /* wb_info_pool is not needed if backlog is zero */
2480 mempool_destroy(mddev->wb_info_pool);
2481 mddev->wb_info_pool = NULL;
2482 } else if (backlog && !mddev->wb_info_pool) {
2483 /* wb_info_pool is needed since backlog is not zero */
2484 struct md_rdev *rdev;
2485
2486 rdev_for_each(rdev, mddev)
2487 mddev_create_wb_pool(mddev, rdev, false);
2488 }
2489 if (old_mwb != backlog)
2490 md_bitmap_update_sb(mddev->bitmap);
2491 return len;
2492}
2493
2494static struct md_sysfs_entry bitmap_backlog =
2495__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2496
2497static ssize_t
2498chunksize_show(struct mddev *mddev, char *page)
2499{
2500 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2501}
2502
2503static ssize_t
2504chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2505{
2506 /* Can only be changed when no bitmap is active */
2507 int rv;
2508 unsigned long csize;
2509 if (mddev->bitmap)
2510 return -EBUSY;
2511 rv = kstrtoul(buf, 10, &csize);
2512 if (rv)
2513 return rv;
2514 if (csize < 512 ||
2515 !is_power_of_2(csize))
2516 return -EINVAL;
2517 mddev->bitmap_info.chunksize = csize;
2518 return len;
2519}
2520
2521static struct md_sysfs_entry bitmap_chunksize =
2522__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2523
2524static ssize_t metadata_show(struct mddev *mddev, char *page)
2525{
2526 if (mddev_is_clustered(mddev))
2527 return sprintf(page, "clustered\n");
2528 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2529 ? "external" : "internal"));
2530}
2531
2532static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2533{
2534 if (mddev->bitmap ||
2535 mddev->bitmap_info.file ||
2536 mddev->bitmap_info.offset)
2537 return -EBUSY;
2538 if (strncmp(buf, "external", 8) == 0)
2539 mddev->bitmap_info.external = 1;
2540 else if ((strncmp(buf, "internal", 8) == 0) ||
2541 (strncmp(buf, "clustered", 9) == 0))
2542 mddev->bitmap_info.external = 0;
2543 else
2544 return -EINVAL;
2545 return len;
2546}
2547
2548static struct md_sysfs_entry bitmap_metadata =
2549__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2550
2551static ssize_t can_clear_show(struct mddev *mddev, char *page)
2552{
2553 int len;
2554 spin_lock(&mddev->lock);
2555 if (mddev->bitmap)
2556 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2557 "false" : "true"));
2558 else
2559 len = sprintf(page, "\n");
2560 spin_unlock(&mddev->lock);
2561 return len;
2562}
2563
2564static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2565{
2566 if (mddev->bitmap == NULL)
2567 return -ENOENT;
2568 if (strncmp(buf, "false", 5) == 0)
2569 mddev->bitmap->need_sync = 1;
2570 else if (strncmp(buf, "true", 4) == 0) {
2571 if (mddev->degraded)
2572 return -EBUSY;
2573 mddev->bitmap->need_sync = 0;
2574 } else
2575 return -EINVAL;
2576 return len;
2577}
2578
2579static struct md_sysfs_entry bitmap_can_clear =
2580__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2581
2582static ssize_t
2583behind_writes_used_show(struct mddev *mddev, char *page)
2584{
2585 ssize_t ret;
2586 spin_lock(&mddev->lock);
2587 if (mddev->bitmap == NULL)
2588 ret = sprintf(page, "0\n");
2589 else
2590 ret = sprintf(page, "%lu\n",
2591 mddev->bitmap->behind_writes_used);
2592 spin_unlock(&mddev->lock);
2593 return ret;
2594}
2595
2596static ssize_t
2597behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2598{
2599 if (mddev->bitmap)
2600 mddev->bitmap->behind_writes_used = 0;
2601 return len;
2602}
2603
2604static struct md_sysfs_entry max_backlog_used =
2605__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2606 behind_writes_used_show, behind_writes_used_reset);
2607
2608static struct attribute *md_bitmap_attrs[] = {
2609 &bitmap_location.attr,
2610 &bitmap_space.attr,
2611 &bitmap_timeout.attr,
2612 &bitmap_backlog.attr,
2613 &bitmap_chunksize.attr,
2614 &bitmap_metadata.attr,
2615 &bitmap_can_clear.attr,
2616 &max_backlog_used.attr,
2617 NULL
2618};
2619struct attribute_group md_bitmap_group = {
2620 .name = "bitmap",
2621 .attrs = md_bitmap_attrs,
2622};
2623