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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, 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 unsigned long blocksize = i_blocksize(inode);
361
362 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
363 (unsigned long long)index << PAGE_SHIFT);
364
365 bh = alloc_page_buffers(page, blocksize, false);
366 if (!bh) {
367 ret = -ENOMEM;
368 goto out;
369 }
370 attach_page_private(page, bh);
371 blk_cur = index << (PAGE_SHIFT - inode->i_blkbits);
372 while (bh) {
373 block = blk_cur;
374
375 if (count == 0)
376 bh->b_blocknr = 0;
377 else {
378 ret = bmap(inode, &block);
379 if (ret || !block) {
380 ret = -EINVAL;
381 bh->b_blocknr = 0;
382 goto out;
383 }
384
385 bh->b_blocknr = block;
386 bh->b_bdev = inode->i_sb->s_bdev;
387 if (count < blocksize)
388 count = 0;
389 else
390 count -= blocksize;
391
392 bh->b_end_io = end_bitmap_write;
393 bh->b_private = bitmap;
394 atomic_inc(&bitmap->pending_writes);
395 set_buffer_locked(bh);
396 set_buffer_mapped(bh);
397 submit_bh(REQ_OP_READ, bh);
398 }
399 blk_cur++;
400 bh = bh->b_this_page;
401 }
402 page->index = index;
403
404 wait_event(bitmap->write_wait,
405 atomic_read(&bitmap->pending_writes)==0);
406 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
407 ret = -EIO;
408out:
409 if (ret)
410 pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
411 (int)PAGE_SIZE,
412 (unsigned long long)index << PAGE_SHIFT,
413 ret);
414 return ret;
415}
416
417/*
418 * bitmap file superblock operations
419 */
420
421/*
422 * md_bitmap_wait_writes() should be called before writing any bitmap
423 * blocks, to ensure previous writes, particularly from
424 * md_bitmap_daemon_work(), have completed.
425 */
426static void md_bitmap_wait_writes(struct bitmap *bitmap)
427{
428 if (bitmap->storage.file)
429 wait_event(bitmap->write_wait,
430 atomic_read(&bitmap->pending_writes)==0);
431 else
432 /* Note that we ignore the return value. The writes
433 * might have failed, but that would just mean that
434 * some bits which should be cleared haven't been,
435 * which is safe. The relevant bitmap blocks will
436 * probably get written again, but there is no great
437 * loss if they aren't.
438 */
439 md_super_wait(bitmap->mddev);
440}
441
442
443/* update the event counter and sync the superblock to disk */
444void md_bitmap_update_sb(struct bitmap *bitmap)
445{
446 bitmap_super_t *sb;
447
448 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
449 return;
450 if (bitmap->mddev->bitmap_info.external)
451 return;
452 if (!bitmap->storage.sb_page) /* no superblock */
453 return;
454 sb = kmap_atomic(bitmap->storage.sb_page);
455 sb->events = cpu_to_le64(bitmap->mddev->events);
456 if (bitmap->mddev->events < bitmap->events_cleared)
457 /* rocking back to read-only */
458 bitmap->events_cleared = bitmap->mddev->events;
459 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
460 /*
461 * clear BITMAP_WRITE_ERROR bit to protect against the case that
462 * a bitmap write error occurred but the later writes succeeded.
463 */
464 sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR));
465 /* Just in case these have been changed via sysfs: */
466 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
467 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
468 /* This might have been changed by a reshape */
469 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
470 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
471 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
472 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
473 bitmap_info.space);
474 kunmap_atomic(sb);
475 write_page(bitmap, bitmap->storage.sb_page, 1);
476}
477EXPORT_SYMBOL(md_bitmap_update_sb);
478
479/* print out the bitmap file superblock */
480void md_bitmap_print_sb(struct bitmap *bitmap)
481{
482 bitmap_super_t *sb;
483
484 if (!bitmap || !bitmap->storage.sb_page)
485 return;
486 sb = kmap_atomic(bitmap->storage.sb_page);
487 pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
488 pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic));
489 pr_debug(" version: %u\n", le32_to_cpu(sb->version));
490 pr_debug(" uuid: %08x.%08x.%08x.%08x\n",
491 le32_to_cpu(*(__le32 *)(sb->uuid+0)),
492 le32_to_cpu(*(__le32 *)(sb->uuid+4)),
493 le32_to_cpu(*(__le32 *)(sb->uuid+8)),
494 le32_to_cpu(*(__le32 *)(sb->uuid+12)));
495 pr_debug(" events: %llu\n",
496 (unsigned long long) le64_to_cpu(sb->events));
497 pr_debug("events cleared: %llu\n",
498 (unsigned long long) le64_to_cpu(sb->events_cleared));
499 pr_debug(" state: %08x\n", le32_to_cpu(sb->state));
500 pr_debug(" chunksize: %u B\n", le32_to_cpu(sb->chunksize));
501 pr_debug(" daemon sleep: %us\n", le32_to_cpu(sb->daemon_sleep));
502 pr_debug(" sync size: %llu KB\n",
503 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
504 pr_debug("max write behind: %u\n", le32_to_cpu(sb->write_behind));
505 kunmap_atomic(sb);
506}
507
508/*
509 * bitmap_new_disk_sb
510 * @bitmap
511 *
512 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
513 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
514 * This function verifies 'bitmap_info' and populates the on-disk bitmap
515 * structure, which is to be written to disk.
516 *
517 * Returns: 0 on success, -Exxx on error
518 */
519static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
520{
521 bitmap_super_t *sb;
522 unsigned long chunksize, daemon_sleep, write_behind;
523
524 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
525 if (bitmap->storage.sb_page == NULL)
526 return -ENOMEM;
527 bitmap->storage.sb_page->index = 0;
528
529 sb = kmap_atomic(bitmap->storage.sb_page);
530
531 sb->magic = cpu_to_le32(BITMAP_MAGIC);
532 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
533
534 chunksize = bitmap->mddev->bitmap_info.chunksize;
535 BUG_ON(!chunksize);
536 if (!is_power_of_2(chunksize)) {
537 kunmap_atomic(sb);
538 pr_warn("bitmap chunksize not a power of 2\n");
539 return -EINVAL;
540 }
541 sb->chunksize = cpu_to_le32(chunksize);
542
543 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
544 if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
545 pr_debug("Choosing daemon_sleep default (5 sec)\n");
546 daemon_sleep = 5 * HZ;
547 }
548 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
549 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
550
551 /*
552 * FIXME: write_behind for RAID1. If not specified, what
553 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
554 */
555 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
556 if (write_behind > COUNTER_MAX)
557 write_behind = COUNTER_MAX / 2;
558 sb->write_behind = cpu_to_le32(write_behind);
559 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
560
561 /* keep the array size field of the bitmap superblock up to date */
562 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
563
564 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
565
566 set_bit(BITMAP_STALE, &bitmap->flags);
567 sb->state = cpu_to_le32(bitmap->flags);
568 bitmap->events_cleared = bitmap->mddev->events;
569 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
570 bitmap->mddev->bitmap_info.nodes = 0;
571
572 kunmap_atomic(sb);
573
574 return 0;
575}
576
577/* read the superblock from the bitmap file and initialize some bitmap fields */
578static int md_bitmap_read_sb(struct bitmap *bitmap)
579{
580 char *reason = NULL;
581 bitmap_super_t *sb;
582 unsigned long chunksize, daemon_sleep, write_behind;
583 unsigned long long events;
584 int nodes = 0;
585 unsigned long sectors_reserved = 0;
586 int err = -EINVAL;
587 struct page *sb_page;
588 loff_t offset = bitmap->mddev->bitmap_info.offset;
589
590 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
591 chunksize = 128 * 1024 * 1024;
592 daemon_sleep = 5 * HZ;
593 write_behind = 0;
594 set_bit(BITMAP_STALE, &bitmap->flags);
595 err = 0;
596 goto out_no_sb;
597 }
598 /* page 0 is the superblock, read it... */
599 sb_page = alloc_page(GFP_KERNEL);
600 if (!sb_page)
601 return -ENOMEM;
602 bitmap->storage.sb_page = sb_page;
603
604re_read:
605 /* If cluster_slot is set, the cluster is setup */
606 if (bitmap->cluster_slot >= 0) {
607 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
608
609 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks,
610 (bitmap->mddev->bitmap_info.chunksize >> 9));
611 /* bits to bytes */
612 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
613 /* to 4k blocks */
614 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
615 offset = bitmap->mddev->bitmap_info.offset + (bitmap->cluster_slot * (bm_blocks << 3));
616 pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
617 bitmap->cluster_slot, offset);
618 }
619
620 if (bitmap->storage.file) {
621 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
622 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
623
624 err = read_page(bitmap->storage.file, 0,
625 bitmap, bytes, sb_page);
626 } else {
627 err = read_sb_page(bitmap->mddev,
628 offset,
629 sb_page,
630 0, sizeof(bitmap_super_t));
631 }
632 if (err)
633 return err;
634
635 err = -EINVAL;
636 sb = kmap_atomic(sb_page);
637
638 chunksize = le32_to_cpu(sb->chunksize);
639 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
640 write_behind = le32_to_cpu(sb->write_behind);
641 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
642
643 /* verify that the bitmap-specific fields are valid */
644 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
645 reason = "bad magic";
646 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
647 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
648 reason = "unrecognized superblock version";
649 else if (chunksize < 512)
650 reason = "bitmap chunksize too small";
651 else if (!is_power_of_2(chunksize))
652 reason = "bitmap chunksize not a power of 2";
653 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
654 reason = "daemon sleep period out of range";
655 else if (write_behind > COUNTER_MAX)
656 reason = "write-behind limit out of range (0 - 16383)";
657 if (reason) {
658 pr_warn("%s: invalid bitmap file superblock: %s\n",
659 bmname(bitmap), reason);
660 goto out;
661 }
662
663 /*
664 * Setup nodes/clustername only if bitmap version is
665 * cluster-compatible
666 */
667 if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
668 nodes = le32_to_cpu(sb->nodes);
669 strscpy(bitmap->mddev->bitmap_info.cluster_name,
670 sb->cluster_name, 64);
671 }
672
673 /* keep the array size field of the bitmap superblock up to date */
674 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
675
676 if (bitmap->mddev->persistent) {
677 /*
678 * We have a persistent array superblock, so compare the
679 * bitmap's UUID and event counter to the mddev's
680 */
681 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
682 pr_warn("%s: bitmap superblock UUID mismatch\n",
683 bmname(bitmap));
684 goto out;
685 }
686 events = le64_to_cpu(sb->events);
687 if (!nodes && (events < bitmap->mddev->events)) {
688 pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
689 bmname(bitmap), events,
690 (unsigned long long) bitmap->mddev->events);
691 set_bit(BITMAP_STALE, &bitmap->flags);
692 }
693 }
694
695 /* assign fields using values from superblock */
696 bitmap->flags |= le32_to_cpu(sb->state);
697 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
698 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
699 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
700 err = 0;
701
702out:
703 kunmap_atomic(sb);
704 if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
705 /* Assigning chunksize is required for "re_read" */
706 bitmap->mddev->bitmap_info.chunksize = chunksize;
707 err = md_setup_cluster(bitmap->mddev, nodes);
708 if (err) {
709 pr_warn("%s: Could not setup cluster service (%d)\n",
710 bmname(bitmap), err);
711 goto out_no_sb;
712 }
713 bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
714 goto re_read;
715 }
716
717out_no_sb:
718 if (err == 0) {
719 if (test_bit(BITMAP_STALE, &bitmap->flags))
720 bitmap->events_cleared = bitmap->mddev->events;
721 bitmap->mddev->bitmap_info.chunksize = chunksize;
722 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
723 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
724 bitmap->mddev->bitmap_info.nodes = nodes;
725 if (bitmap->mddev->bitmap_info.space == 0 ||
726 bitmap->mddev->bitmap_info.space > sectors_reserved)
727 bitmap->mddev->bitmap_info.space = sectors_reserved;
728 } else {
729 md_bitmap_print_sb(bitmap);
730 if (bitmap->cluster_slot < 0)
731 md_cluster_stop(bitmap->mddev);
732 }
733 return err;
734}
735
736/*
737 * general bitmap file operations
738 */
739
740/*
741 * on-disk bitmap:
742 *
743 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
744 * file a page at a time. There's a superblock at the start of the file.
745 */
746/* calculate the index of the page that contains this bit */
747static inline unsigned long file_page_index(struct bitmap_storage *store,
748 unsigned long chunk)
749{
750 if (store->sb_page)
751 chunk += sizeof(bitmap_super_t) << 3;
752 return chunk >> PAGE_BIT_SHIFT;
753}
754
755/* calculate the (bit) offset of this bit within a page */
756static inline unsigned long file_page_offset(struct bitmap_storage *store,
757 unsigned long chunk)
758{
759 if (store->sb_page)
760 chunk += sizeof(bitmap_super_t) << 3;
761 return chunk & (PAGE_BITS - 1);
762}
763
764/*
765 * return a pointer to the page in the filemap that contains the given bit
766 *
767 */
768static inline struct page *filemap_get_page(struct bitmap_storage *store,
769 unsigned long chunk)
770{
771 if (file_page_index(store, chunk) >= store->file_pages)
772 return NULL;
773 return store->filemap[file_page_index(store, chunk)];
774}
775
776static int md_bitmap_storage_alloc(struct bitmap_storage *store,
777 unsigned long chunks, int with_super,
778 int slot_number)
779{
780 int pnum, offset = 0;
781 unsigned long num_pages;
782 unsigned long bytes;
783
784 bytes = DIV_ROUND_UP(chunks, 8);
785 if (with_super)
786 bytes += sizeof(bitmap_super_t);
787
788 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
789 offset = slot_number * num_pages;
790
791 store->filemap = kmalloc_array(num_pages, sizeof(struct page *),
792 GFP_KERNEL);
793 if (!store->filemap)
794 return -ENOMEM;
795
796 if (with_super && !store->sb_page) {
797 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
798 if (store->sb_page == NULL)
799 return -ENOMEM;
800 }
801
802 pnum = 0;
803 if (store->sb_page) {
804 store->filemap[0] = store->sb_page;
805 pnum = 1;
806 store->sb_page->index = offset;
807 }
808
809 for ( ; pnum < num_pages; pnum++) {
810 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
811 if (!store->filemap[pnum]) {
812 store->file_pages = pnum;
813 return -ENOMEM;
814 }
815 store->filemap[pnum]->index = pnum + offset;
816 }
817 store->file_pages = pnum;
818
819 /* We need 4 bits per page, rounded up to a multiple
820 * of sizeof(unsigned long) */
821 store->filemap_attr = kzalloc(
822 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
823 GFP_KERNEL);
824 if (!store->filemap_attr)
825 return -ENOMEM;
826
827 store->bytes = bytes;
828
829 return 0;
830}
831
832static void md_bitmap_file_unmap(struct bitmap_storage *store)
833{
834 struct page **map, *sb_page;
835 int pages;
836 struct file *file;
837
838 file = store->file;
839 map = store->filemap;
840 pages = store->file_pages;
841 sb_page = store->sb_page;
842
843 while (pages--)
844 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
845 free_buffers(map[pages]);
846 kfree(map);
847 kfree(store->filemap_attr);
848
849 if (sb_page)
850 free_buffers(sb_page);
851
852 if (file) {
853 struct inode *inode = file_inode(file);
854 invalidate_mapping_pages(inode->i_mapping, 0, -1);
855 fput(file);
856 }
857}
858
859/*
860 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
861 * then it is no longer reliable, so we stop using it and we mark the file
862 * as failed in the superblock
863 */
864static void md_bitmap_file_kick(struct bitmap *bitmap)
865{
866 char *path, *ptr = NULL;
867
868 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
869 md_bitmap_update_sb(bitmap);
870
871 if (bitmap->storage.file) {
872 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
873 if (path)
874 ptr = file_path(bitmap->storage.file,
875 path, PAGE_SIZE);
876
877 pr_warn("%s: kicking failed bitmap file %s from array!\n",
878 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
879
880 kfree(path);
881 } else
882 pr_warn("%s: disabling internal bitmap due to errors\n",
883 bmname(bitmap));
884 }
885}
886
887enum bitmap_page_attr {
888 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
889 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
890 * i.e. counter is 1 or 2. */
891 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
892};
893
894static inline void set_page_attr(struct bitmap *bitmap, int pnum,
895 enum bitmap_page_attr attr)
896{
897 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
898}
899
900static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
901 enum bitmap_page_attr attr)
902{
903 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
904}
905
906static inline int test_page_attr(struct bitmap *bitmap, int pnum,
907 enum bitmap_page_attr attr)
908{
909 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
910}
911
912static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
913 enum bitmap_page_attr attr)
914{
915 return test_and_clear_bit((pnum<<2) + attr,
916 bitmap->storage.filemap_attr);
917}
918/*
919 * bitmap_file_set_bit -- called before performing a write to the md device
920 * to set (and eventually sync) a particular bit in the bitmap file
921 *
922 * we set the bit immediately, then we record the page number so that
923 * when an unplug occurs, we can flush the dirty pages out to disk
924 */
925static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
926{
927 unsigned long bit;
928 struct page *page;
929 void *kaddr;
930 unsigned long chunk = block >> bitmap->counts.chunkshift;
931 struct bitmap_storage *store = &bitmap->storage;
932 unsigned long node_offset = 0;
933
934 if (mddev_is_clustered(bitmap->mddev))
935 node_offset = bitmap->cluster_slot * store->file_pages;
936
937 page = filemap_get_page(&bitmap->storage, chunk);
938 if (!page)
939 return;
940 bit = file_page_offset(&bitmap->storage, chunk);
941
942 /* set the bit */
943 kaddr = kmap_atomic(page);
944 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
945 set_bit(bit, kaddr);
946 else
947 set_bit_le(bit, kaddr);
948 kunmap_atomic(kaddr);
949 pr_debug("set file bit %lu page %lu\n", bit, page->index);
950 /* record page number so it gets flushed to disk when unplug occurs */
951 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_DIRTY);
952}
953
954static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
955{
956 unsigned long bit;
957 struct page *page;
958 void *paddr;
959 unsigned long chunk = block >> bitmap->counts.chunkshift;
960 struct bitmap_storage *store = &bitmap->storage;
961 unsigned long node_offset = 0;
962
963 if (mddev_is_clustered(bitmap->mddev))
964 node_offset = bitmap->cluster_slot * store->file_pages;
965
966 page = filemap_get_page(&bitmap->storage, chunk);
967 if (!page)
968 return;
969 bit = file_page_offset(&bitmap->storage, chunk);
970 paddr = kmap_atomic(page);
971 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
972 clear_bit(bit, paddr);
973 else
974 clear_bit_le(bit, paddr);
975 kunmap_atomic(paddr);
976 if (!test_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
977 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_PENDING);
978 bitmap->allclean = 0;
979 }
980}
981
982static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
983{
984 unsigned long bit;
985 struct page *page;
986 void *paddr;
987 unsigned long chunk = block >> bitmap->counts.chunkshift;
988 int set = 0;
989
990 page = filemap_get_page(&bitmap->storage, chunk);
991 if (!page)
992 return -EINVAL;
993 bit = file_page_offset(&bitmap->storage, chunk);
994 paddr = kmap_atomic(page);
995 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
996 set = test_bit(bit, paddr);
997 else
998 set = test_bit_le(bit, paddr);
999 kunmap_atomic(paddr);
1000 return set;
1001}
1002
1003
1004/* this gets called when the md device is ready to unplug its underlying
1005 * (slave) device queues -- before we let any writes go down, we need to
1006 * sync the dirty pages of the bitmap file to disk */
1007void md_bitmap_unplug(struct bitmap *bitmap)
1008{
1009 unsigned long i;
1010 int dirty, need_write;
1011 int writing = 0;
1012
1013 if (!bitmap || !bitmap->storage.filemap ||
1014 test_bit(BITMAP_STALE, &bitmap->flags))
1015 return;
1016
1017 /* look at each page to see if there are any set bits that need to be
1018 * flushed out to disk */
1019 for (i = 0; i < bitmap->storage.file_pages; i++) {
1020 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1021 need_write = test_and_clear_page_attr(bitmap, i,
1022 BITMAP_PAGE_NEEDWRITE);
1023 if (dirty || need_write) {
1024 if (!writing) {
1025 md_bitmap_wait_writes(bitmap);
1026 if (bitmap->mddev->queue)
1027 blk_add_trace_msg(bitmap->mddev->queue,
1028 "md bitmap_unplug");
1029 }
1030 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
1031 write_page(bitmap, bitmap->storage.filemap[i], 0);
1032 writing = 1;
1033 }
1034 }
1035 if (writing)
1036 md_bitmap_wait_writes(bitmap);
1037
1038 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1039 md_bitmap_file_kick(bitmap);
1040}
1041EXPORT_SYMBOL(md_bitmap_unplug);
1042
1043static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1044/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
1045 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
1046 * memory mapping of the bitmap file
1047 * Special cases:
1048 * if there's no bitmap file, or if the bitmap file had been
1049 * previously kicked from the array, we mark all the bits as
1050 * 1's in order to cause a full resync.
1051 *
1052 * We ignore all bits for sectors that end earlier than 'start'.
1053 * This is used when reading an out-of-date bitmap...
1054 */
1055static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1056{
1057 unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
1058 struct page *page = NULL;
1059 unsigned long bit_cnt = 0;
1060 struct file *file;
1061 unsigned long offset;
1062 int outofdate;
1063 int ret = -ENOSPC;
1064 void *paddr;
1065 struct bitmap_storage *store = &bitmap->storage;
1066
1067 chunks = bitmap->counts.chunks;
1068 file = store->file;
1069
1070 if (!file && !bitmap->mddev->bitmap_info.offset) {
1071 /* No permanent bitmap - fill with '1s'. */
1072 store->filemap = NULL;
1073 store->file_pages = 0;
1074 for (i = 0; i < chunks ; i++) {
1075 /* if the disk bit is set, set the memory bit */
1076 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1077 >= start);
1078 md_bitmap_set_memory_bits(bitmap,
1079 (sector_t)i << bitmap->counts.chunkshift,
1080 needed);
1081 }
1082 return 0;
1083 }
1084
1085 outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1086 if (outofdate)
1087 pr_warn("%s: bitmap file is out of date, doing full recovery\n", bmname(bitmap));
1088
1089 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
1090 pr_warn("%s: bitmap file too short %lu < %lu\n",
1091 bmname(bitmap),
1092 (unsigned long) i_size_read(file->f_mapping->host),
1093 store->bytes);
1094 goto err;
1095 }
1096
1097 oldindex = ~0L;
1098 offset = 0;
1099 if (!bitmap->mddev->bitmap_info.external)
1100 offset = sizeof(bitmap_super_t);
1101
1102 if (mddev_is_clustered(bitmap->mddev))
1103 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1104
1105 for (i = 0; i < chunks; i++) {
1106 int b;
1107 index = file_page_index(&bitmap->storage, i);
1108 bit = file_page_offset(&bitmap->storage, i);
1109 if (index != oldindex) { /* this is a new page, read it in */
1110 int count;
1111 /* unmap the old page, we're done with it */
1112 if (index == store->file_pages-1)
1113 count = store->bytes - index * PAGE_SIZE;
1114 else
1115 count = PAGE_SIZE;
1116 page = store->filemap[index];
1117 if (file)
1118 ret = read_page(file, index, bitmap,
1119 count, page);
1120 else
1121 ret = read_sb_page(
1122 bitmap->mddev,
1123 bitmap->mddev->bitmap_info.offset,
1124 page,
1125 index + node_offset, count);
1126
1127 if (ret)
1128 goto err;
1129
1130 oldindex = index;
1131
1132 if (outofdate) {
1133 /*
1134 * if bitmap is out of date, dirty the
1135 * whole page and write it out
1136 */
1137 paddr = kmap_atomic(page);
1138 memset(paddr + offset, 0xff,
1139 PAGE_SIZE - offset);
1140 kunmap_atomic(paddr);
1141 write_page(bitmap, page, 1);
1142
1143 ret = -EIO;
1144 if (test_bit(BITMAP_WRITE_ERROR,
1145 &bitmap->flags))
1146 goto err;
1147 }
1148 }
1149 paddr = kmap_atomic(page);
1150 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1151 b = test_bit(bit, paddr);
1152 else
1153 b = test_bit_le(bit, paddr);
1154 kunmap_atomic(paddr);
1155 if (b) {
1156 /* if the disk bit is set, set the memory bit */
1157 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1158 >= start);
1159 md_bitmap_set_memory_bits(bitmap,
1160 (sector_t)i << bitmap->counts.chunkshift,
1161 needed);
1162 bit_cnt++;
1163 }
1164 offset = 0;
1165 }
1166
1167 pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
1168 bmname(bitmap), store->file_pages,
1169 bit_cnt, chunks);
1170
1171 return 0;
1172
1173 err:
1174 pr_warn("%s: bitmap initialisation failed: %d\n",
1175 bmname(bitmap), ret);
1176 return ret;
1177}
1178
1179void md_bitmap_write_all(struct bitmap *bitmap)
1180{
1181 /* We don't actually write all bitmap blocks here,
1182 * just flag them as needing to be written
1183 */
1184 int i;
1185
1186 if (!bitmap || !bitmap->storage.filemap)
1187 return;
1188 if (bitmap->storage.file)
1189 /* Only one copy, so nothing needed */
1190 return;
1191
1192 for (i = 0; i < bitmap->storage.file_pages; i++)
1193 set_page_attr(bitmap, i,
1194 BITMAP_PAGE_NEEDWRITE);
1195 bitmap->allclean = 0;
1196}
1197
1198static void md_bitmap_count_page(struct bitmap_counts *bitmap,
1199 sector_t offset, int inc)
1200{
1201 sector_t chunk = offset >> bitmap->chunkshift;
1202 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1203 bitmap->bp[page].count += inc;
1204 md_bitmap_checkfree(bitmap, page);
1205}
1206
1207static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1208{
1209 sector_t chunk = offset >> bitmap->chunkshift;
1210 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1211 struct bitmap_page *bp = &bitmap->bp[page];
1212
1213 if (!bp->pending)
1214 bp->pending = 1;
1215}
1216
1217static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1218 sector_t offset, sector_t *blocks,
1219 int create);
1220
1221/*
1222 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1223 * out to disk
1224 */
1225
1226void md_bitmap_daemon_work(struct mddev *mddev)
1227{
1228 struct bitmap *bitmap;
1229 unsigned long j;
1230 unsigned long nextpage;
1231 sector_t blocks;
1232 struct bitmap_counts *counts;
1233
1234 /* Use a mutex to guard daemon_work against
1235 * bitmap_destroy.
1236 */
1237 mutex_lock(&mddev->bitmap_info.mutex);
1238 bitmap = mddev->bitmap;
1239 if (bitmap == NULL) {
1240 mutex_unlock(&mddev->bitmap_info.mutex);
1241 return;
1242 }
1243 if (time_before(jiffies, bitmap->daemon_lastrun
1244 + mddev->bitmap_info.daemon_sleep))
1245 goto done;
1246
1247 bitmap->daemon_lastrun = jiffies;
1248 if (bitmap->allclean) {
1249 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1250 goto done;
1251 }
1252 bitmap->allclean = 1;
1253
1254 if (bitmap->mddev->queue)
1255 blk_add_trace_msg(bitmap->mddev->queue,
1256 "md bitmap_daemon_work");
1257
1258 /* Any file-page which is PENDING now needs to be written.
1259 * So set NEEDWRITE now, then after we make any last-minute changes
1260 * we will write it.
1261 */
1262 for (j = 0; j < bitmap->storage.file_pages; j++)
1263 if (test_and_clear_page_attr(bitmap, j,
1264 BITMAP_PAGE_PENDING))
1265 set_page_attr(bitmap, j,
1266 BITMAP_PAGE_NEEDWRITE);
1267
1268 if (bitmap->need_sync &&
1269 mddev->bitmap_info.external == 0) {
1270 /* Arrange for superblock update as well as
1271 * other changes */
1272 bitmap_super_t *sb;
1273 bitmap->need_sync = 0;
1274 if (bitmap->storage.filemap) {
1275 sb = kmap_atomic(bitmap->storage.sb_page);
1276 sb->events_cleared =
1277 cpu_to_le64(bitmap->events_cleared);
1278 kunmap_atomic(sb);
1279 set_page_attr(bitmap, 0,
1280 BITMAP_PAGE_NEEDWRITE);
1281 }
1282 }
1283 /* Now look at the bitmap counters and if any are '2' or '1',
1284 * decrement and handle accordingly.
1285 */
1286 counts = &bitmap->counts;
1287 spin_lock_irq(&counts->lock);
1288 nextpage = 0;
1289 for (j = 0; j < counts->chunks; j++) {
1290 bitmap_counter_t *bmc;
1291 sector_t block = (sector_t)j << counts->chunkshift;
1292
1293 if (j == nextpage) {
1294 nextpage += PAGE_COUNTER_RATIO;
1295 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1296 j |= PAGE_COUNTER_MASK;
1297 continue;
1298 }
1299 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1300 }
1301
1302 bmc = md_bitmap_get_counter(counts, block, &blocks, 0);
1303 if (!bmc) {
1304 j |= PAGE_COUNTER_MASK;
1305 continue;
1306 }
1307 if (*bmc == 1 && !bitmap->need_sync) {
1308 /* We can clear the bit */
1309 *bmc = 0;
1310 md_bitmap_count_page(counts, block, -1);
1311 md_bitmap_file_clear_bit(bitmap, block);
1312 } else if (*bmc && *bmc <= 2) {
1313 *bmc = 1;
1314 md_bitmap_set_pending(counts, block);
1315 bitmap->allclean = 0;
1316 }
1317 }
1318 spin_unlock_irq(&counts->lock);
1319
1320 md_bitmap_wait_writes(bitmap);
1321 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1322 * DIRTY pages need to be written by bitmap_unplug so it can wait
1323 * for them.
1324 * If we find any DIRTY page we stop there and let bitmap_unplug
1325 * handle all the rest. This is important in the case where
1326 * the first blocking holds the superblock and it has been updated.
1327 * We mustn't write any other blocks before the superblock.
1328 */
1329 for (j = 0;
1330 j < bitmap->storage.file_pages
1331 && !test_bit(BITMAP_STALE, &bitmap->flags);
1332 j++) {
1333 if (test_page_attr(bitmap, j,
1334 BITMAP_PAGE_DIRTY))
1335 /* bitmap_unplug will handle the rest */
1336 break;
1337 if (bitmap->storage.filemap &&
1338 test_and_clear_page_attr(bitmap, j,
1339 BITMAP_PAGE_NEEDWRITE)) {
1340 write_page(bitmap, bitmap->storage.filemap[j], 0);
1341 }
1342 }
1343
1344 done:
1345 if (bitmap->allclean == 0)
1346 mddev->thread->timeout =
1347 mddev->bitmap_info.daemon_sleep;
1348 mutex_unlock(&mddev->bitmap_info.mutex);
1349}
1350
1351static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1352 sector_t offset, sector_t *blocks,
1353 int create)
1354__releases(bitmap->lock)
1355__acquires(bitmap->lock)
1356{
1357 /* If 'create', we might release the lock and reclaim it.
1358 * The lock must have been taken with interrupts enabled.
1359 * If !create, we don't release the lock.
1360 */
1361 sector_t chunk = offset >> bitmap->chunkshift;
1362 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1363 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1364 sector_t csize;
1365 int err;
1366
1367 err = md_bitmap_checkpage(bitmap, page, create, 0);
1368
1369 if (bitmap->bp[page].hijacked ||
1370 bitmap->bp[page].map == NULL)
1371 csize = ((sector_t)1) << (bitmap->chunkshift +
1372 PAGE_COUNTER_SHIFT);
1373 else
1374 csize = ((sector_t)1) << bitmap->chunkshift;
1375 *blocks = csize - (offset & (csize - 1));
1376
1377 if (err < 0)
1378 return NULL;
1379
1380 /* now locked ... */
1381
1382 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1383 /* should we use the first or second counter field
1384 * of the hijacked pointer? */
1385 int hi = (pageoff > PAGE_COUNTER_MASK);
1386 return &((bitmap_counter_t *)
1387 &bitmap->bp[page].map)[hi];
1388 } else /* page is allocated */
1389 return (bitmap_counter_t *)
1390 &(bitmap->bp[page].map[pageoff]);
1391}
1392
1393int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1394{
1395 if (!bitmap)
1396 return 0;
1397
1398 if (behind) {
1399 int bw;
1400 atomic_inc(&bitmap->behind_writes);
1401 bw = atomic_read(&bitmap->behind_writes);
1402 if (bw > bitmap->behind_writes_used)
1403 bitmap->behind_writes_used = bw;
1404
1405 pr_debug("inc write-behind count %d/%lu\n",
1406 bw, bitmap->mddev->bitmap_info.max_write_behind);
1407 }
1408
1409 while (sectors) {
1410 sector_t blocks;
1411 bitmap_counter_t *bmc;
1412
1413 spin_lock_irq(&bitmap->counts.lock);
1414 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1415 if (!bmc) {
1416 spin_unlock_irq(&bitmap->counts.lock);
1417 return 0;
1418 }
1419
1420 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1421 DEFINE_WAIT(__wait);
1422 /* note that it is safe to do the prepare_to_wait
1423 * after the test as long as we do it before dropping
1424 * the spinlock.
1425 */
1426 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1427 TASK_UNINTERRUPTIBLE);
1428 spin_unlock_irq(&bitmap->counts.lock);
1429 schedule();
1430 finish_wait(&bitmap->overflow_wait, &__wait);
1431 continue;
1432 }
1433
1434 switch (*bmc) {
1435 case 0:
1436 md_bitmap_file_set_bit(bitmap, offset);
1437 md_bitmap_count_page(&bitmap->counts, offset, 1);
1438 fallthrough;
1439 case 1:
1440 *bmc = 2;
1441 }
1442
1443 (*bmc)++;
1444
1445 spin_unlock_irq(&bitmap->counts.lock);
1446
1447 offset += blocks;
1448 if (sectors > blocks)
1449 sectors -= blocks;
1450 else
1451 sectors = 0;
1452 }
1453 return 0;
1454}
1455EXPORT_SYMBOL(md_bitmap_startwrite);
1456
1457void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
1458 unsigned long sectors, int success, int behind)
1459{
1460 if (!bitmap)
1461 return;
1462 if (behind) {
1463 if (atomic_dec_and_test(&bitmap->behind_writes))
1464 wake_up(&bitmap->behind_wait);
1465 pr_debug("dec write-behind count %d/%lu\n",
1466 atomic_read(&bitmap->behind_writes),
1467 bitmap->mddev->bitmap_info.max_write_behind);
1468 }
1469
1470 while (sectors) {
1471 sector_t blocks;
1472 unsigned long flags;
1473 bitmap_counter_t *bmc;
1474
1475 spin_lock_irqsave(&bitmap->counts.lock, flags);
1476 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1477 if (!bmc) {
1478 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1479 return;
1480 }
1481
1482 if (success && !bitmap->mddev->degraded &&
1483 bitmap->events_cleared < bitmap->mddev->events) {
1484 bitmap->events_cleared = bitmap->mddev->events;
1485 bitmap->need_sync = 1;
1486 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1487 }
1488
1489 if (!success && !NEEDED(*bmc))
1490 *bmc |= NEEDED_MASK;
1491
1492 if (COUNTER(*bmc) == COUNTER_MAX)
1493 wake_up(&bitmap->overflow_wait);
1494
1495 (*bmc)--;
1496 if (*bmc <= 2) {
1497 md_bitmap_set_pending(&bitmap->counts, offset);
1498 bitmap->allclean = 0;
1499 }
1500 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1501 offset += blocks;
1502 if (sectors > blocks)
1503 sectors -= blocks;
1504 else
1505 sectors = 0;
1506 }
1507}
1508EXPORT_SYMBOL(md_bitmap_endwrite);
1509
1510static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1511 int degraded)
1512{
1513 bitmap_counter_t *bmc;
1514 int rv;
1515 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1516 *blocks = 1024;
1517 return 1; /* always resync if no bitmap */
1518 }
1519 spin_lock_irq(&bitmap->counts.lock);
1520 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1521 rv = 0;
1522 if (bmc) {
1523 /* locked */
1524 if (RESYNC(*bmc))
1525 rv = 1;
1526 else if (NEEDED(*bmc)) {
1527 rv = 1;
1528 if (!degraded) { /* don't set/clear bits if degraded */
1529 *bmc |= RESYNC_MASK;
1530 *bmc &= ~NEEDED_MASK;
1531 }
1532 }
1533 }
1534 spin_unlock_irq(&bitmap->counts.lock);
1535 return rv;
1536}
1537
1538int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1539 int degraded)
1540{
1541 /* bitmap_start_sync must always report on multiples of whole
1542 * pages, otherwise resync (which is very PAGE_SIZE based) will
1543 * get confused.
1544 * So call __bitmap_start_sync repeatedly (if needed) until
1545 * At least PAGE_SIZE>>9 blocks are covered.
1546 * Return the 'or' of the result.
1547 */
1548 int rv = 0;
1549 sector_t blocks1;
1550
1551 *blocks = 0;
1552 while (*blocks < (PAGE_SIZE>>9)) {
1553 rv |= __bitmap_start_sync(bitmap, offset,
1554 &blocks1, degraded);
1555 offset += blocks1;
1556 *blocks += blocks1;
1557 }
1558 return rv;
1559}
1560EXPORT_SYMBOL(md_bitmap_start_sync);
1561
1562void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1563{
1564 bitmap_counter_t *bmc;
1565 unsigned long flags;
1566
1567 if (bitmap == NULL) {
1568 *blocks = 1024;
1569 return;
1570 }
1571 spin_lock_irqsave(&bitmap->counts.lock, flags);
1572 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1573 if (bmc == NULL)
1574 goto unlock;
1575 /* locked */
1576 if (RESYNC(*bmc)) {
1577 *bmc &= ~RESYNC_MASK;
1578
1579 if (!NEEDED(*bmc) && aborted)
1580 *bmc |= NEEDED_MASK;
1581 else {
1582 if (*bmc <= 2) {
1583 md_bitmap_set_pending(&bitmap->counts, offset);
1584 bitmap->allclean = 0;
1585 }
1586 }
1587 }
1588 unlock:
1589 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1590}
1591EXPORT_SYMBOL(md_bitmap_end_sync);
1592
1593void md_bitmap_close_sync(struct bitmap *bitmap)
1594{
1595 /* Sync has finished, and any bitmap chunks that weren't synced
1596 * properly have been aborted. It remains to us to clear the
1597 * RESYNC bit wherever it is still on
1598 */
1599 sector_t sector = 0;
1600 sector_t blocks;
1601 if (!bitmap)
1602 return;
1603 while (sector < bitmap->mddev->resync_max_sectors) {
1604 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1605 sector += blocks;
1606 }
1607}
1608EXPORT_SYMBOL(md_bitmap_close_sync);
1609
1610void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
1611{
1612 sector_t s = 0;
1613 sector_t blocks;
1614
1615 if (!bitmap)
1616 return;
1617 if (sector == 0) {
1618 bitmap->last_end_sync = jiffies;
1619 return;
1620 }
1621 if (!force && time_before(jiffies, (bitmap->last_end_sync
1622 + bitmap->mddev->bitmap_info.daemon_sleep)))
1623 return;
1624 wait_event(bitmap->mddev->recovery_wait,
1625 atomic_read(&bitmap->mddev->recovery_active) == 0);
1626
1627 bitmap->mddev->curr_resync_completed = sector;
1628 set_bit(MD_SB_CHANGE_CLEAN, &bitmap->mddev->sb_flags);
1629 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1630 s = 0;
1631 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1632 md_bitmap_end_sync(bitmap, s, &blocks, 0);
1633 s += blocks;
1634 }
1635 bitmap->last_end_sync = jiffies;
1636 sysfs_notify_dirent_safe(bitmap->mddev->sysfs_completed);
1637}
1638EXPORT_SYMBOL(md_bitmap_cond_end_sync);
1639
1640void md_bitmap_sync_with_cluster(struct mddev *mddev,
1641 sector_t old_lo, sector_t old_hi,
1642 sector_t new_lo, sector_t new_hi)
1643{
1644 struct bitmap *bitmap = mddev->bitmap;
1645 sector_t sector, blocks = 0;
1646
1647 for (sector = old_lo; sector < new_lo; ) {
1648 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1649 sector += blocks;
1650 }
1651 WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
1652
1653 for (sector = old_hi; sector < new_hi; ) {
1654 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1655 sector += blocks;
1656 }
1657 WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
1658}
1659EXPORT_SYMBOL(md_bitmap_sync_with_cluster);
1660
1661static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1662{
1663 /* For each chunk covered by any of these sectors, set the
1664 * counter to 2 and possibly set resync_needed. They should all
1665 * be 0 at this point
1666 */
1667
1668 sector_t secs;
1669 bitmap_counter_t *bmc;
1670 spin_lock_irq(&bitmap->counts.lock);
1671 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1672 if (!bmc) {
1673 spin_unlock_irq(&bitmap->counts.lock);
1674 return;
1675 }
1676 if (!*bmc) {
1677 *bmc = 2;
1678 md_bitmap_count_page(&bitmap->counts, offset, 1);
1679 md_bitmap_set_pending(&bitmap->counts, offset);
1680 bitmap->allclean = 0;
1681 }
1682 if (needed)
1683 *bmc |= NEEDED_MASK;
1684 spin_unlock_irq(&bitmap->counts.lock);
1685}
1686
1687/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1688void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1689{
1690 unsigned long chunk;
1691
1692 for (chunk = s; chunk <= e; chunk++) {
1693 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1694 md_bitmap_set_memory_bits(bitmap, sec, 1);
1695 md_bitmap_file_set_bit(bitmap, sec);
1696 if (sec < bitmap->mddev->recovery_cp)
1697 /* We are asserting that the array is dirty,
1698 * so move the recovery_cp address back so
1699 * that it is obvious that it is dirty
1700 */
1701 bitmap->mddev->recovery_cp = sec;
1702 }
1703}
1704
1705/*
1706 * flush out any pending updates
1707 */
1708void md_bitmap_flush(struct mddev *mddev)
1709{
1710 struct bitmap *bitmap = mddev->bitmap;
1711 long sleep;
1712
1713 if (!bitmap) /* there was no bitmap */
1714 return;
1715
1716 /* run the daemon_work three time to ensure everything is flushed
1717 * that can be
1718 */
1719 sleep = mddev->bitmap_info.daemon_sleep * 2;
1720 bitmap->daemon_lastrun -= sleep;
1721 md_bitmap_daemon_work(mddev);
1722 bitmap->daemon_lastrun -= sleep;
1723 md_bitmap_daemon_work(mddev);
1724 bitmap->daemon_lastrun -= sleep;
1725 md_bitmap_daemon_work(mddev);
1726 if (mddev->bitmap_info.external)
1727 md_super_wait(mddev);
1728 md_bitmap_update_sb(bitmap);
1729}
1730
1731/*
1732 * free memory that was allocated
1733 */
1734void md_bitmap_free(struct bitmap *bitmap)
1735{
1736 unsigned long k, pages;
1737 struct bitmap_page *bp;
1738
1739 if (!bitmap) /* there was no bitmap */
1740 return;
1741
1742 if (bitmap->sysfs_can_clear)
1743 sysfs_put(bitmap->sysfs_can_clear);
1744
1745 if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
1746 bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
1747 md_cluster_stop(bitmap->mddev);
1748
1749 /* Shouldn't be needed - but just in case.... */
1750 wait_event(bitmap->write_wait,
1751 atomic_read(&bitmap->pending_writes) == 0);
1752
1753 /* release the bitmap file */
1754 md_bitmap_file_unmap(&bitmap->storage);
1755
1756 bp = bitmap->counts.bp;
1757 pages = bitmap->counts.pages;
1758
1759 /* free all allocated memory */
1760
1761 if (bp) /* deallocate the page memory */
1762 for (k = 0; k < pages; k++)
1763 if (bp[k].map && !bp[k].hijacked)
1764 kfree(bp[k].map);
1765 kfree(bp);
1766 kfree(bitmap);
1767}
1768EXPORT_SYMBOL(md_bitmap_free);
1769
1770void md_bitmap_wait_behind_writes(struct mddev *mddev)
1771{
1772 struct bitmap *bitmap = mddev->bitmap;
1773
1774 /* wait for behind writes to complete */
1775 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1776 pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
1777 mdname(mddev));
1778 /* need to kick something here to make sure I/O goes? */
1779 wait_event(bitmap->behind_wait,
1780 atomic_read(&bitmap->behind_writes) == 0);
1781 }
1782}
1783
1784void md_bitmap_destroy(struct mddev *mddev)
1785{
1786 struct bitmap *bitmap = mddev->bitmap;
1787
1788 if (!bitmap) /* there was no bitmap */
1789 return;
1790
1791 md_bitmap_wait_behind_writes(mddev);
1792 if (!mddev->serialize_policy)
1793 mddev_destroy_serial_pool(mddev, NULL, true);
1794
1795 mutex_lock(&mddev->bitmap_info.mutex);
1796 spin_lock(&mddev->lock);
1797 mddev->bitmap = NULL; /* disconnect from the md device */
1798 spin_unlock(&mddev->lock);
1799 mutex_unlock(&mddev->bitmap_info.mutex);
1800 if (mddev->thread)
1801 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1802
1803 md_bitmap_free(bitmap);
1804}
1805
1806/*
1807 * initialize the bitmap structure
1808 * if this returns an error, bitmap_destroy must be called to do clean up
1809 * once mddev->bitmap is set
1810 */
1811struct bitmap *md_bitmap_create(struct mddev *mddev, int slot)
1812{
1813 struct bitmap *bitmap;
1814 sector_t blocks = mddev->resync_max_sectors;
1815 struct file *file = mddev->bitmap_info.file;
1816 int err;
1817 struct kernfs_node *bm = NULL;
1818
1819 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1820
1821 BUG_ON(file && mddev->bitmap_info.offset);
1822
1823 if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
1824 pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
1825 mdname(mddev));
1826 return ERR_PTR(-EBUSY);
1827 }
1828
1829 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1830 if (!bitmap)
1831 return ERR_PTR(-ENOMEM);
1832
1833 spin_lock_init(&bitmap->counts.lock);
1834 atomic_set(&bitmap->pending_writes, 0);
1835 init_waitqueue_head(&bitmap->write_wait);
1836 init_waitqueue_head(&bitmap->overflow_wait);
1837 init_waitqueue_head(&bitmap->behind_wait);
1838
1839 bitmap->mddev = mddev;
1840 bitmap->cluster_slot = slot;
1841
1842 if (mddev->kobj.sd)
1843 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
1844 if (bm) {
1845 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
1846 sysfs_put(bm);
1847 } else
1848 bitmap->sysfs_can_clear = NULL;
1849
1850 bitmap->storage.file = file;
1851 if (file) {
1852 get_file(file);
1853 /* As future accesses to this file will use bmap,
1854 * and bypass the page cache, we must sync the file
1855 * first.
1856 */
1857 vfs_fsync(file, 1);
1858 }
1859 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1860 if (!mddev->bitmap_info.external) {
1861 /*
1862 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1863 * instructing us to create a new on-disk bitmap instance.
1864 */
1865 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1866 err = md_bitmap_new_disk_sb(bitmap);
1867 else
1868 err = md_bitmap_read_sb(bitmap);
1869 } else {
1870 err = 0;
1871 if (mddev->bitmap_info.chunksize == 0 ||
1872 mddev->bitmap_info.daemon_sleep == 0)
1873 /* chunksize and time_base need to be
1874 * set first. */
1875 err = -EINVAL;
1876 }
1877 if (err)
1878 goto error;
1879
1880 bitmap->daemon_lastrun = jiffies;
1881 err = md_bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1882 if (err)
1883 goto error;
1884
1885 pr_debug("created bitmap (%lu pages) for device %s\n",
1886 bitmap->counts.pages, bmname(bitmap));
1887
1888 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1889 if (err)
1890 goto error;
1891
1892 return bitmap;
1893 error:
1894 md_bitmap_free(bitmap);
1895 return ERR_PTR(err);
1896}
1897
1898int md_bitmap_load(struct mddev *mddev)
1899{
1900 int err = 0;
1901 sector_t start = 0;
1902 sector_t sector = 0;
1903 struct bitmap *bitmap = mddev->bitmap;
1904 struct md_rdev *rdev;
1905
1906 if (!bitmap)
1907 goto out;
1908
1909 rdev_for_each(rdev, mddev)
1910 mddev_create_serial_pool(mddev, rdev, true);
1911
1912 if (mddev_is_clustered(mddev))
1913 md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
1914
1915 /* Clear out old bitmap info first: Either there is none, or we
1916 * are resuming after someone else has possibly changed things,
1917 * so we should forget old cached info.
1918 * All chunks should be clean, but some might need_sync.
1919 */
1920 while (sector < mddev->resync_max_sectors) {
1921 sector_t blocks;
1922 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1923 sector += blocks;
1924 }
1925 md_bitmap_close_sync(bitmap);
1926
1927 if (mddev->degraded == 0
1928 || bitmap->events_cleared == mddev->events)
1929 /* no need to keep dirty bits to optimise a
1930 * re-add of a missing device */
1931 start = mddev->recovery_cp;
1932
1933 mutex_lock(&mddev->bitmap_info.mutex);
1934 err = md_bitmap_init_from_disk(bitmap, start);
1935 mutex_unlock(&mddev->bitmap_info.mutex);
1936
1937 if (err)
1938 goto out;
1939 clear_bit(BITMAP_STALE, &bitmap->flags);
1940
1941 /* Kick recovery in case any bits were set */
1942 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1943
1944 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1945 md_wakeup_thread(mddev->thread);
1946
1947 md_bitmap_update_sb(bitmap);
1948
1949 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1950 err = -EIO;
1951out:
1952 return err;
1953}
1954EXPORT_SYMBOL_GPL(md_bitmap_load);
1955
1956/* caller need to free returned bitmap with md_bitmap_free() */
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 md_bitmap_free(bitmap);
2021
2022 return rv;
2023}
2024EXPORT_SYMBOL_GPL(md_bitmap_copy_from_slot);
2025
2026
2027void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
2028{
2029 unsigned long chunk_kb;
2030 struct bitmap_counts *counts;
2031
2032 if (!bitmap)
2033 return;
2034
2035 counts = &bitmap->counts;
2036
2037 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
2038 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
2039 "%lu%s chunk",
2040 counts->pages - counts->missing_pages,
2041 counts->pages,
2042 (counts->pages - counts->missing_pages)
2043 << (PAGE_SHIFT - 10),
2044 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
2045 chunk_kb ? "KB" : "B");
2046 if (bitmap->storage.file) {
2047 seq_printf(seq, ", file: ");
2048 seq_file_path(seq, bitmap->storage.file, " \t\n");
2049 }
2050
2051 seq_printf(seq, "\n");
2052}
2053
2054int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
2055 int chunksize, int init)
2056{
2057 /* If chunk_size is 0, choose an appropriate chunk size.
2058 * Then possibly allocate new storage space.
2059 * Then quiesce, copy bits, replace bitmap, and re-start
2060 *
2061 * This function is called both to set up the initial bitmap
2062 * and to resize the bitmap while the array is active.
2063 * If this happens as a result of the array being resized,
2064 * chunksize will be zero, and we need to choose a suitable
2065 * chunksize, otherwise we use what we are given.
2066 */
2067 struct bitmap_storage store;
2068 struct bitmap_counts old_counts;
2069 unsigned long chunks;
2070 sector_t block;
2071 sector_t old_blocks, new_blocks;
2072 int chunkshift;
2073 int ret = 0;
2074 long pages;
2075 struct bitmap_page *new_bp;
2076
2077 if (bitmap->storage.file && !init) {
2078 pr_info("md: cannot resize file-based bitmap\n");
2079 return -EINVAL;
2080 }
2081
2082 if (chunksize == 0) {
2083 /* If there is enough space, leave the chunk size unchanged,
2084 * else increase by factor of two until there is enough space.
2085 */
2086 long bytes;
2087 long space = bitmap->mddev->bitmap_info.space;
2088
2089 if (space == 0) {
2090 /* We don't know how much space there is, so limit
2091 * to current size - in sectors.
2092 */
2093 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
2094 if (!bitmap->mddev->bitmap_info.external)
2095 bytes += sizeof(bitmap_super_t);
2096 space = DIV_ROUND_UP(bytes, 512);
2097 bitmap->mddev->bitmap_info.space = space;
2098 }
2099 chunkshift = bitmap->counts.chunkshift;
2100 chunkshift--;
2101 do {
2102 /* 'chunkshift' is shift from block size to chunk size */
2103 chunkshift++;
2104 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2105 bytes = DIV_ROUND_UP(chunks, 8);
2106 if (!bitmap->mddev->bitmap_info.external)
2107 bytes += sizeof(bitmap_super_t);
2108 } while (bytes > (space << 9) && (chunkshift + BITMAP_BLOCK_SHIFT) <
2109 (BITS_PER_BYTE * sizeof(((bitmap_super_t *)0)->chunksize) - 1));
2110 } else
2111 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
2112
2113 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2114 memset(&store, 0, sizeof(store));
2115 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2116 ret = md_bitmap_storage_alloc(&store, chunks,
2117 !bitmap->mddev->bitmap_info.external,
2118 mddev_is_clustered(bitmap->mddev)
2119 ? bitmap->cluster_slot : 0);
2120 if (ret) {
2121 md_bitmap_file_unmap(&store);
2122 goto err;
2123 }
2124
2125 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2126
2127 new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
2128 ret = -ENOMEM;
2129 if (!new_bp) {
2130 md_bitmap_file_unmap(&store);
2131 goto err;
2132 }
2133
2134 if (!init)
2135 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2136
2137 store.file = bitmap->storage.file;
2138 bitmap->storage.file = NULL;
2139
2140 if (store.sb_page && bitmap->storage.sb_page)
2141 memcpy(page_address(store.sb_page),
2142 page_address(bitmap->storage.sb_page),
2143 sizeof(bitmap_super_t));
2144 spin_lock_irq(&bitmap->counts.lock);
2145 md_bitmap_file_unmap(&bitmap->storage);
2146 bitmap->storage = store;
2147
2148 old_counts = bitmap->counts;
2149 bitmap->counts.bp = new_bp;
2150 bitmap->counts.pages = pages;
2151 bitmap->counts.missing_pages = pages;
2152 bitmap->counts.chunkshift = chunkshift;
2153 bitmap->counts.chunks = chunks;
2154 bitmap->mddev->bitmap_info.chunksize = 1UL << (chunkshift +
2155 BITMAP_BLOCK_SHIFT);
2156
2157 blocks = min(old_counts.chunks << old_counts.chunkshift,
2158 chunks << chunkshift);
2159
2160 /* For cluster raid, need to pre-allocate bitmap */
2161 if (mddev_is_clustered(bitmap->mddev)) {
2162 unsigned long page;
2163 for (page = 0; page < pages; page++) {
2164 ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1);
2165 if (ret) {
2166 unsigned long k;
2167
2168 /* deallocate the page memory */
2169 for (k = 0; k < page; k++) {
2170 kfree(new_bp[k].map);
2171 }
2172 kfree(new_bp);
2173
2174 /* restore some fields from old_counts */
2175 bitmap->counts.bp = old_counts.bp;
2176 bitmap->counts.pages = old_counts.pages;
2177 bitmap->counts.missing_pages = old_counts.pages;
2178 bitmap->counts.chunkshift = old_counts.chunkshift;
2179 bitmap->counts.chunks = old_counts.chunks;
2180 bitmap->mddev->bitmap_info.chunksize =
2181 1UL << (old_counts.chunkshift + BITMAP_BLOCK_SHIFT);
2182 blocks = old_counts.chunks << old_counts.chunkshift;
2183 pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
2184 break;
2185 } else
2186 bitmap->counts.bp[page].count += 1;
2187 }
2188 }
2189
2190 for (block = 0; block < blocks; ) {
2191 bitmap_counter_t *bmc_old, *bmc_new;
2192 int set;
2193
2194 bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0);
2195 set = bmc_old && NEEDED(*bmc_old);
2196
2197 if (set) {
2198 bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2199 if (bmc_new) {
2200 if (*bmc_new == 0) {
2201 /* need to set on-disk bits too. */
2202 sector_t end = block + new_blocks;
2203 sector_t start = block >> chunkshift;
2204
2205 start <<= chunkshift;
2206 while (start < end) {
2207 md_bitmap_file_set_bit(bitmap, block);
2208 start += 1 << chunkshift;
2209 }
2210 *bmc_new = 2;
2211 md_bitmap_count_page(&bitmap->counts, block, 1);
2212 md_bitmap_set_pending(&bitmap->counts, block);
2213 }
2214 *bmc_new |= NEEDED_MASK;
2215 }
2216 if (new_blocks < old_blocks)
2217 old_blocks = new_blocks;
2218 }
2219 block += old_blocks;
2220 }
2221
2222 if (bitmap->counts.bp != old_counts.bp) {
2223 unsigned long k;
2224 for (k = 0; k < old_counts.pages; k++)
2225 if (!old_counts.bp[k].hijacked)
2226 kfree(old_counts.bp[k].map);
2227 kfree(old_counts.bp);
2228 }
2229
2230 if (!init) {
2231 int i;
2232 while (block < (chunks << chunkshift)) {
2233 bitmap_counter_t *bmc;
2234 bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2235 if (bmc) {
2236 /* new space. It needs to be resynced, so
2237 * we set NEEDED_MASK.
2238 */
2239 if (*bmc == 0) {
2240 *bmc = NEEDED_MASK | 2;
2241 md_bitmap_count_page(&bitmap->counts, block, 1);
2242 md_bitmap_set_pending(&bitmap->counts, block);
2243 }
2244 }
2245 block += new_blocks;
2246 }
2247 for (i = 0; i < bitmap->storage.file_pages; i++)
2248 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
2249 }
2250 spin_unlock_irq(&bitmap->counts.lock);
2251
2252 if (!init) {
2253 md_bitmap_unplug(bitmap);
2254 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2255 }
2256 ret = 0;
2257err:
2258 return ret;
2259}
2260EXPORT_SYMBOL_GPL(md_bitmap_resize);
2261
2262static ssize_t
2263location_show(struct mddev *mddev, char *page)
2264{
2265 ssize_t len;
2266 if (mddev->bitmap_info.file)
2267 len = sprintf(page, "file");
2268 else if (mddev->bitmap_info.offset)
2269 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
2270 else
2271 len = sprintf(page, "none");
2272 len += sprintf(page+len, "\n");
2273 return len;
2274}
2275
2276static ssize_t
2277location_store(struct mddev *mddev, const char *buf, size_t len)
2278{
2279 int rv;
2280
2281 rv = mddev_lock(mddev);
2282 if (rv)
2283 return rv;
2284 if (mddev->pers) {
2285 if (!mddev->pers->quiesce) {
2286 rv = -EBUSY;
2287 goto out;
2288 }
2289 if (mddev->recovery || mddev->sync_thread) {
2290 rv = -EBUSY;
2291 goto out;
2292 }
2293 }
2294
2295 if (mddev->bitmap || mddev->bitmap_info.file ||
2296 mddev->bitmap_info.offset) {
2297 /* bitmap already configured. Only option is to clear it */
2298 if (strncmp(buf, "none", 4) != 0) {
2299 rv = -EBUSY;
2300 goto out;
2301 }
2302 if (mddev->pers) {
2303 mddev_suspend(mddev);
2304 md_bitmap_destroy(mddev);
2305 mddev_resume(mddev);
2306 }
2307 mddev->bitmap_info.offset = 0;
2308 if (mddev->bitmap_info.file) {
2309 struct file *f = mddev->bitmap_info.file;
2310 mddev->bitmap_info.file = NULL;
2311 fput(f);
2312 }
2313 } else {
2314 /* No bitmap, OK to set a location */
2315 long long offset;
2316 if (strncmp(buf, "none", 4) == 0)
2317 /* nothing to be done */;
2318 else if (strncmp(buf, "file:", 5) == 0) {
2319 /* Not supported yet */
2320 rv = -EINVAL;
2321 goto out;
2322 } else {
2323 if (buf[0] == '+')
2324 rv = kstrtoll(buf+1, 10, &offset);
2325 else
2326 rv = kstrtoll(buf, 10, &offset);
2327 if (rv)
2328 goto out;
2329 if (offset == 0) {
2330 rv = -EINVAL;
2331 goto out;
2332 }
2333 if (mddev->bitmap_info.external == 0 &&
2334 mddev->major_version == 0 &&
2335 offset != mddev->bitmap_info.default_offset) {
2336 rv = -EINVAL;
2337 goto out;
2338 }
2339 mddev->bitmap_info.offset = offset;
2340 if (mddev->pers) {
2341 struct bitmap *bitmap;
2342 bitmap = md_bitmap_create(mddev, -1);
2343 mddev_suspend(mddev);
2344 if (IS_ERR(bitmap))
2345 rv = PTR_ERR(bitmap);
2346 else {
2347 mddev->bitmap = bitmap;
2348 rv = md_bitmap_load(mddev);
2349 if (rv)
2350 mddev->bitmap_info.offset = 0;
2351 }
2352 if (rv) {
2353 md_bitmap_destroy(mddev);
2354 mddev_resume(mddev);
2355 goto out;
2356 }
2357 mddev_resume(mddev);
2358 }
2359 }
2360 }
2361 if (!mddev->external) {
2362 /* Ensure new bitmap info is stored in
2363 * metadata promptly.
2364 */
2365 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2366 md_wakeup_thread(mddev->thread);
2367 }
2368 rv = 0;
2369out:
2370 mddev_unlock(mddev);
2371 if (rv)
2372 return rv;
2373 return len;
2374}
2375
2376static struct md_sysfs_entry bitmap_location =
2377__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2378
2379/* 'bitmap/space' is the space available at 'location' for the
2380 * bitmap. This allows the kernel to know when it is safe to
2381 * resize the bitmap to match a resized array.
2382 */
2383static ssize_t
2384space_show(struct mddev *mddev, char *page)
2385{
2386 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2387}
2388
2389static ssize_t
2390space_store(struct mddev *mddev, const char *buf, size_t len)
2391{
2392 unsigned long sectors;
2393 int rv;
2394
2395 rv = kstrtoul(buf, 10, §ors);
2396 if (rv)
2397 return rv;
2398
2399 if (sectors == 0)
2400 return -EINVAL;
2401
2402 if (mddev->bitmap &&
2403 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2404 return -EFBIG; /* Bitmap is too big for this small space */
2405
2406 /* could make sure it isn't too big, but that isn't really
2407 * needed - user-space should be careful.
2408 */
2409 mddev->bitmap_info.space = sectors;
2410 return len;
2411}
2412
2413static struct md_sysfs_entry bitmap_space =
2414__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2415
2416static ssize_t
2417timeout_show(struct mddev *mddev, char *page)
2418{
2419 ssize_t len;
2420 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2421 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2422
2423 len = sprintf(page, "%lu", secs);
2424 if (jifs)
2425 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2426 len += sprintf(page+len, "\n");
2427 return len;
2428}
2429
2430static ssize_t
2431timeout_store(struct mddev *mddev, const char *buf, size_t len)
2432{
2433 /* timeout can be set at any time */
2434 unsigned long timeout;
2435 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2436 if (rv)
2437 return rv;
2438
2439 /* just to make sure we don't overflow... */
2440 if (timeout >= LONG_MAX / HZ)
2441 return -EINVAL;
2442
2443 timeout = timeout * HZ / 10000;
2444
2445 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2446 timeout = MAX_SCHEDULE_TIMEOUT-1;
2447 if (timeout < 1)
2448 timeout = 1;
2449 mddev->bitmap_info.daemon_sleep = timeout;
2450 if (mddev->thread) {
2451 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
2452 * the bitmap is all clean and we don't need to
2453 * adjust the timeout right now
2454 */
2455 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2456 mddev->thread->timeout = timeout;
2457 md_wakeup_thread(mddev->thread);
2458 }
2459 }
2460 return len;
2461}
2462
2463static struct md_sysfs_entry bitmap_timeout =
2464__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2465
2466static ssize_t
2467backlog_show(struct mddev *mddev, char *page)
2468{
2469 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2470}
2471
2472static ssize_t
2473backlog_store(struct mddev *mddev, const char *buf, size_t len)
2474{
2475 unsigned long backlog;
2476 unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
2477 struct md_rdev *rdev;
2478 bool has_write_mostly = false;
2479 int rv = kstrtoul(buf, 10, &backlog);
2480 if (rv)
2481 return rv;
2482 if (backlog > COUNTER_MAX)
2483 return -EINVAL;
2484
2485 /*
2486 * Without write mostly device, it doesn't make sense to set
2487 * backlog for max_write_behind.
2488 */
2489 rdev_for_each(rdev, mddev) {
2490 if (test_bit(WriteMostly, &rdev->flags)) {
2491 has_write_mostly = true;
2492 break;
2493 }
2494 }
2495 if (!has_write_mostly) {
2496 pr_warn_ratelimited("%s: can't set backlog, no write mostly device available\n",
2497 mdname(mddev));
2498 return -EINVAL;
2499 }
2500
2501 mddev->bitmap_info.max_write_behind = backlog;
2502 if (!backlog && mddev->serial_info_pool) {
2503 /* serial_info_pool is not needed if backlog is zero */
2504 if (!mddev->serialize_policy)
2505 mddev_destroy_serial_pool(mddev, NULL, false);
2506 } else if (backlog && !mddev->serial_info_pool) {
2507 /* serial_info_pool is needed since backlog is not zero */
2508 struct md_rdev *rdev;
2509
2510 rdev_for_each(rdev, mddev)
2511 mddev_create_serial_pool(mddev, rdev, false);
2512 }
2513 if (old_mwb != backlog)
2514 md_bitmap_update_sb(mddev->bitmap);
2515 return len;
2516}
2517
2518static struct md_sysfs_entry bitmap_backlog =
2519__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2520
2521static ssize_t
2522chunksize_show(struct mddev *mddev, char *page)
2523{
2524 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2525}
2526
2527static ssize_t
2528chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2529{
2530 /* Can only be changed when no bitmap is active */
2531 int rv;
2532 unsigned long csize;
2533 if (mddev->bitmap)
2534 return -EBUSY;
2535 rv = kstrtoul(buf, 10, &csize);
2536 if (rv)
2537 return rv;
2538 if (csize < 512 ||
2539 !is_power_of_2(csize))
2540 return -EINVAL;
2541 if (BITS_PER_LONG > 32 && csize >= (1ULL << (BITS_PER_BYTE *
2542 sizeof(((bitmap_super_t *)0)->chunksize))))
2543 return -EOVERFLOW;
2544 mddev->bitmap_info.chunksize = csize;
2545 return len;
2546}
2547
2548static struct md_sysfs_entry bitmap_chunksize =
2549__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2550
2551static ssize_t metadata_show(struct mddev *mddev, char *page)
2552{
2553 if (mddev_is_clustered(mddev))
2554 return sprintf(page, "clustered\n");
2555 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2556 ? "external" : "internal"));
2557}
2558
2559static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2560{
2561 if (mddev->bitmap ||
2562 mddev->bitmap_info.file ||
2563 mddev->bitmap_info.offset)
2564 return -EBUSY;
2565 if (strncmp(buf, "external", 8) == 0)
2566 mddev->bitmap_info.external = 1;
2567 else if ((strncmp(buf, "internal", 8) == 0) ||
2568 (strncmp(buf, "clustered", 9) == 0))
2569 mddev->bitmap_info.external = 0;
2570 else
2571 return -EINVAL;
2572 return len;
2573}
2574
2575static struct md_sysfs_entry bitmap_metadata =
2576__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2577
2578static ssize_t can_clear_show(struct mddev *mddev, char *page)
2579{
2580 int len;
2581 spin_lock(&mddev->lock);
2582 if (mddev->bitmap)
2583 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2584 "false" : "true"));
2585 else
2586 len = sprintf(page, "\n");
2587 spin_unlock(&mddev->lock);
2588 return len;
2589}
2590
2591static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2592{
2593 if (mddev->bitmap == NULL)
2594 return -ENOENT;
2595 if (strncmp(buf, "false", 5) == 0)
2596 mddev->bitmap->need_sync = 1;
2597 else if (strncmp(buf, "true", 4) == 0) {
2598 if (mddev->degraded)
2599 return -EBUSY;
2600 mddev->bitmap->need_sync = 0;
2601 } else
2602 return -EINVAL;
2603 return len;
2604}
2605
2606static struct md_sysfs_entry bitmap_can_clear =
2607__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2608
2609static ssize_t
2610behind_writes_used_show(struct mddev *mddev, char *page)
2611{
2612 ssize_t ret;
2613 spin_lock(&mddev->lock);
2614 if (mddev->bitmap == NULL)
2615 ret = sprintf(page, "0\n");
2616 else
2617 ret = sprintf(page, "%lu\n",
2618 mddev->bitmap->behind_writes_used);
2619 spin_unlock(&mddev->lock);
2620 return ret;
2621}
2622
2623static ssize_t
2624behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2625{
2626 if (mddev->bitmap)
2627 mddev->bitmap->behind_writes_used = 0;
2628 return len;
2629}
2630
2631static struct md_sysfs_entry max_backlog_used =
2632__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2633 behind_writes_used_show, behind_writes_used_reset);
2634
2635static struct attribute *md_bitmap_attrs[] = {
2636 &bitmap_location.attr,
2637 &bitmap_space.attr,
2638 &bitmap_timeout.attr,
2639 &bitmap_backlog.attr,
2640 &bitmap_chunksize.attr,
2641 &bitmap_metadata.attr,
2642 &bitmap_can_clear.attr,
2643 &max_backlog_used.attr,
2644 NULL
2645};
2646const struct attribute_group md_bitmap_group = {
2647 .name = "bitmap",
2648 .attrs = md_bitmap_attrs,
2649};