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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 WARN_ON_ONCE(page >= bitmap->pages);
58 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
59 return 0;
60
61 if (bitmap->bp[page].map) /* page is already allocated, just return */
62 return 0;
63
64 if (!create)
65 return -ENOENT;
66
67 /* this page has not been allocated yet */
68
69 spin_unlock_irq(&bitmap->lock);
70 /* It is possible that this is being called inside a
71 * prepare_to_wait/finish_wait loop from raid5c:make_request().
72 * In general it is not permitted to sleep in that context as it
73 * can cause the loop to spin freely.
74 * That doesn't apply here as we can only reach this point
75 * once with any loop.
76 * When this function completes, either bp[page].map or
77 * bp[page].hijacked. In either case, this function will
78 * abort before getting to this point again. So there is
79 * no risk of a free-spin, and so it is safe to assert
80 * that sleeping here is allowed.
81 */
82 sched_annotate_sleep();
83 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
84 spin_lock_irq(&bitmap->lock);
85
86 if (mappage == NULL) {
87 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
88 /* We don't support hijack for cluster raid */
89 if (no_hijack)
90 return -ENOMEM;
91 /* failed - set the hijacked flag so that we can use the
92 * pointer as a counter */
93 if (!bitmap->bp[page].map)
94 bitmap->bp[page].hijacked = 1;
95 } else if (bitmap->bp[page].map ||
96 bitmap->bp[page].hijacked) {
97 /* somebody beat us to getting the page */
98 kfree(mappage);
99 } else {
100
101 /* no page was in place and we have one, so install it */
102
103 bitmap->bp[page].map = mappage;
104 bitmap->missing_pages--;
105 }
106 return 0;
107}
108
109/* if page is completely empty, put it back on the free list, or dealloc it */
110/* if page was hijacked, unmark the flag so it might get alloced next time */
111/* Note: lock should be held when calling this */
112static void md_bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
113{
114 char *ptr;
115
116 if (bitmap->bp[page].count) /* page is still busy */
117 return;
118
119 /* page is no longer in use, it can be released */
120
121 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
122 bitmap->bp[page].hijacked = 0;
123 bitmap->bp[page].map = NULL;
124 } else {
125 /* normal case, free the page */
126 ptr = bitmap->bp[page].map;
127 bitmap->bp[page].map = NULL;
128 bitmap->missing_pages++;
129 kfree(ptr);
130 }
131}
132
133/*
134 * bitmap file handling - read and write the bitmap file and its superblock
135 */
136
137/*
138 * basic page I/O operations
139 */
140
141/* IO operations when bitmap is stored near all superblocks */
142
143/* choose a good rdev and read the page from there */
144static int read_sb_page(struct mddev *mddev, loff_t offset,
145 struct page *page, unsigned long index, int size)
146{
147
148 sector_t sector = mddev->bitmap_info.offset + offset +
149 index * (PAGE_SIZE / SECTOR_SIZE);
150 struct md_rdev *rdev;
151
152 rdev_for_each(rdev, mddev) {
153 u32 iosize = roundup(size, bdev_logical_block_size(rdev->bdev));
154
155 if (!test_bit(In_sync, &rdev->flags) ||
156 test_bit(Faulty, &rdev->flags) ||
157 test_bit(Bitmap_sync, &rdev->flags))
158 continue;
159
160 if (sync_page_io(rdev, sector, iosize, page, REQ_OP_READ, true))
161 return 0;
162 }
163 return -EIO;
164}
165
166static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
167{
168 /* Iterate the disks of an mddev, using rcu to protect access to the
169 * linked list, and raising the refcount of devices we return to ensure
170 * they don't disappear while in use.
171 * As devices are only added or removed when raid_disk is < 0 and
172 * nr_pending is 0 and In_sync is clear, the entries we return will
173 * still be in the same position on the list when we re-enter
174 * list_for_each_entry_continue_rcu.
175 *
176 * Note that if entered with 'rdev == NULL' to start at the
177 * beginning, we temporarily assign 'rdev' to an address which
178 * isn't really an rdev, but which can be used by
179 * list_for_each_entry_continue_rcu() to find the first entry.
180 */
181 rcu_read_lock();
182 if (rdev == NULL)
183 /* start at the beginning */
184 rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
185 else {
186 /* release the previous rdev and start from there. */
187 rdev_dec_pending(rdev, mddev);
188 }
189 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
190 if (rdev->raid_disk >= 0 &&
191 !test_bit(Faulty, &rdev->flags)) {
192 /* this is a usable devices */
193 atomic_inc(&rdev->nr_pending);
194 rcu_read_unlock();
195 return rdev;
196 }
197 }
198 rcu_read_unlock();
199 return NULL;
200}
201
202static unsigned int optimal_io_size(struct block_device *bdev,
203 unsigned int last_page_size,
204 unsigned int io_size)
205{
206 if (bdev_io_opt(bdev) > bdev_logical_block_size(bdev))
207 return roundup(last_page_size, bdev_io_opt(bdev));
208 return io_size;
209}
210
211static unsigned int bitmap_io_size(unsigned int io_size, unsigned int opt_size,
212 loff_t start, loff_t boundary)
213{
214 if (io_size != opt_size &&
215 start + opt_size / SECTOR_SIZE <= boundary)
216 return opt_size;
217 if (start + io_size / SECTOR_SIZE <= boundary)
218 return io_size;
219
220 /* Overflows boundary */
221 return 0;
222}
223
224static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
225 unsigned long pg_index, struct page *page)
226{
227 struct block_device *bdev;
228 struct mddev *mddev = bitmap->mddev;
229 struct bitmap_storage *store = &bitmap->storage;
230 loff_t sboff, offset = mddev->bitmap_info.offset;
231 sector_t ps = pg_index * PAGE_SIZE / SECTOR_SIZE;
232 unsigned int size = PAGE_SIZE;
233 unsigned int opt_size = PAGE_SIZE;
234 sector_t doff;
235
236 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
237 if (pg_index == store->file_pages - 1) {
238 unsigned int last_page_size = store->bytes & (PAGE_SIZE - 1);
239
240 if (last_page_size == 0)
241 last_page_size = PAGE_SIZE;
242 size = roundup(last_page_size, bdev_logical_block_size(bdev));
243 opt_size = optimal_io_size(bdev, last_page_size, size);
244 }
245
246 sboff = rdev->sb_start + offset;
247 doff = rdev->data_offset;
248
249 /* Just make sure we aren't corrupting data or metadata */
250 if (mddev->external) {
251 /* Bitmap could be anywhere. */
252 if (sboff + ps > doff &&
253 sboff < (doff + mddev->dev_sectors + PAGE_SIZE / SECTOR_SIZE))
254 return -EINVAL;
255 } else if (offset < 0) {
256 /* DATA BITMAP METADATA */
257 size = bitmap_io_size(size, opt_size, offset + ps, 0);
258 if (size == 0)
259 /* bitmap runs in to metadata */
260 return -EINVAL;
261
262 if (doff + mddev->dev_sectors > sboff)
263 /* data runs in to bitmap */
264 return -EINVAL;
265 } else if (rdev->sb_start < rdev->data_offset) {
266 /* METADATA BITMAP DATA */
267 size = bitmap_io_size(size, opt_size, sboff + ps, doff);
268 if (size == 0)
269 /* bitmap runs in to data */
270 return -EINVAL;
271 } else {
272 /* DATA METADATA BITMAP - no problems */
273 }
274
275 md_super_write(mddev, rdev, sboff + ps, (int) size, page);
276 return 0;
277}
278
279static void write_sb_page(struct bitmap *bitmap, unsigned long pg_index,
280 struct page *page, bool wait)
281{
282 struct mddev *mddev = bitmap->mddev;
283
284 do {
285 struct md_rdev *rdev = NULL;
286
287 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
288 if (__write_sb_page(rdev, bitmap, pg_index, page) < 0) {
289 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
290 return;
291 }
292 }
293 } while (wait && md_super_wait(mddev) < 0);
294}
295
296static void md_bitmap_file_kick(struct bitmap *bitmap);
297
298#ifdef CONFIG_MD_BITMAP_FILE
299static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
300{
301 struct buffer_head *bh = page_buffers(page);
302
303 while (bh && bh->b_blocknr) {
304 atomic_inc(&bitmap->pending_writes);
305 set_buffer_locked(bh);
306 set_buffer_mapped(bh);
307 submit_bh(REQ_OP_WRITE | REQ_SYNC, bh);
308 bh = bh->b_this_page;
309 }
310
311 if (wait)
312 wait_event(bitmap->write_wait,
313 atomic_read(&bitmap->pending_writes) == 0);
314}
315
316static void end_bitmap_write(struct buffer_head *bh, int uptodate)
317{
318 struct bitmap *bitmap = bh->b_private;
319
320 if (!uptodate)
321 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
322 if (atomic_dec_and_test(&bitmap->pending_writes))
323 wake_up(&bitmap->write_wait);
324}
325
326static void free_buffers(struct page *page)
327{
328 struct buffer_head *bh;
329
330 if (!PagePrivate(page))
331 return;
332
333 bh = page_buffers(page);
334 while (bh) {
335 struct buffer_head *next = bh->b_this_page;
336 free_buffer_head(bh);
337 bh = next;
338 }
339 detach_page_private(page);
340 put_page(page);
341}
342
343/* read a page from a file.
344 * We both read the page, and attach buffers to the page to record the
345 * address of each block (using bmap). These addresses will be used
346 * to write the block later, completely bypassing the filesystem.
347 * This usage is similar to how swap files are handled, and allows us
348 * to write to a file with no concerns of memory allocation failing.
349 */
350static int read_file_page(struct file *file, unsigned long index,
351 struct bitmap *bitmap, unsigned long count, struct page *page)
352{
353 int ret = 0;
354 struct inode *inode = file_inode(file);
355 struct buffer_head *bh;
356 sector_t block, blk_cur;
357 unsigned long blocksize = i_blocksize(inode);
358
359 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
360 (unsigned long long)index << PAGE_SHIFT);
361
362 bh = alloc_page_buffers(page, blocksize, false);
363 if (!bh) {
364 ret = -ENOMEM;
365 goto out;
366 }
367 attach_page_private(page, bh);
368 blk_cur = index << (PAGE_SHIFT - inode->i_blkbits);
369 while (bh) {
370 block = blk_cur;
371
372 if (count == 0)
373 bh->b_blocknr = 0;
374 else {
375 ret = bmap(inode, &block);
376 if (ret || !block) {
377 ret = -EINVAL;
378 bh->b_blocknr = 0;
379 goto out;
380 }
381
382 bh->b_blocknr = block;
383 bh->b_bdev = inode->i_sb->s_bdev;
384 if (count < blocksize)
385 count = 0;
386 else
387 count -= blocksize;
388
389 bh->b_end_io = end_bitmap_write;
390 bh->b_private = bitmap;
391 atomic_inc(&bitmap->pending_writes);
392 set_buffer_locked(bh);
393 set_buffer_mapped(bh);
394 submit_bh(REQ_OP_READ, bh);
395 }
396 blk_cur++;
397 bh = bh->b_this_page;
398 }
399
400 wait_event(bitmap->write_wait,
401 atomic_read(&bitmap->pending_writes)==0);
402 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
403 ret = -EIO;
404out:
405 if (ret)
406 pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
407 (int)PAGE_SIZE,
408 (unsigned long long)index << PAGE_SHIFT,
409 ret);
410 return ret;
411}
412#else /* CONFIG_MD_BITMAP_FILE */
413static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
414{
415}
416static int read_file_page(struct file *file, unsigned long index,
417 struct bitmap *bitmap, unsigned long count, struct page *page)
418{
419 return -EIO;
420}
421static void free_buffers(struct page *page)
422{
423 put_page(page);
424}
425#endif /* CONFIG_MD_BITMAP_FILE */
426
427/*
428 * bitmap file superblock operations
429 */
430
431/*
432 * write out a page to a file
433 */
434static void filemap_write_page(struct bitmap *bitmap, unsigned long pg_index,
435 bool wait)
436{
437 struct bitmap_storage *store = &bitmap->storage;
438 struct page *page = store->filemap[pg_index];
439
440 if (mddev_is_clustered(bitmap->mddev)) {
441 pg_index += bitmap->cluster_slot *
442 DIV_ROUND_UP(store->bytes, PAGE_SIZE);
443 }
444
445 if (store->file)
446 write_file_page(bitmap, page, wait);
447 else
448 write_sb_page(bitmap, pg_index, page, wait);
449}
450
451/*
452 * md_bitmap_wait_writes() should be called before writing any bitmap
453 * blocks, to ensure previous writes, particularly from
454 * md_bitmap_daemon_work(), have completed.
455 */
456static void md_bitmap_wait_writes(struct bitmap *bitmap)
457{
458 if (bitmap->storage.file)
459 wait_event(bitmap->write_wait,
460 atomic_read(&bitmap->pending_writes)==0);
461 else
462 /* Note that we ignore the return value. The writes
463 * might have failed, but that would just mean that
464 * some bits which should be cleared haven't been,
465 * which is safe. The relevant bitmap blocks will
466 * probably get written again, but there is no great
467 * loss if they aren't.
468 */
469 md_super_wait(bitmap->mddev);
470}
471
472
473/* update the event counter and sync the superblock to disk */
474void md_bitmap_update_sb(struct bitmap *bitmap)
475{
476 bitmap_super_t *sb;
477
478 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
479 return;
480 if (bitmap->mddev->bitmap_info.external)
481 return;
482 if (!bitmap->storage.sb_page) /* no superblock */
483 return;
484 sb = kmap_atomic(bitmap->storage.sb_page);
485 sb->events = cpu_to_le64(bitmap->mddev->events);
486 if (bitmap->mddev->events < bitmap->events_cleared)
487 /* rocking back to read-only */
488 bitmap->events_cleared = bitmap->mddev->events;
489 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
490 /*
491 * clear BITMAP_WRITE_ERROR bit to protect against the case that
492 * a bitmap write error occurred but the later writes succeeded.
493 */
494 sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR));
495 /* Just in case these have been changed via sysfs: */
496 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
497 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
498 /* This might have been changed by a reshape */
499 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
500 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
501 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
502 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
503 bitmap_info.space);
504 kunmap_atomic(sb);
505
506 if (bitmap->storage.file)
507 write_file_page(bitmap, bitmap->storage.sb_page, 1);
508 else
509 write_sb_page(bitmap, bitmap->storage.sb_index,
510 bitmap->storage.sb_page, 1);
511}
512EXPORT_SYMBOL(md_bitmap_update_sb);
513
514/* print out the bitmap file superblock */
515void md_bitmap_print_sb(struct bitmap *bitmap)
516{
517 bitmap_super_t *sb;
518
519 if (!bitmap || !bitmap->storage.sb_page)
520 return;
521 sb = kmap_atomic(bitmap->storage.sb_page);
522 pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
523 pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic));
524 pr_debug(" version: %u\n", le32_to_cpu(sb->version));
525 pr_debug(" uuid: %08x.%08x.%08x.%08x\n",
526 le32_to_cpu(*(__le32 *)(sb->uuid+0)),
527 le32_to_cpu(*(__le32 *)(sb->uuid+4)),
528 le32_to_cpu(*(__le32 *)(sb->uuid+8)),
529 le32_to_cpu(*(__le32 *)(sb->uuid+12)));
530 pr_debug(" events: %llu\n",
531 (unsigned long long) le64_to_cpu(sb->events));
532 pr_debug("events cleared: %llu\n",
533 (unsigned long long) le64_to_cpu(sb->events_cleared));
534 pr_debug(" state: %08x\n", le32_to_cpu(sb->state));
535 pr_debug(" chunksize: %u B\n", le32_to_cpu(sb->chunksize));
536 pr_debug(" daemon sleep: %us\n", le32_to_cpu(sb->daemon_sleep));
537 pr_debug(" sync size: %llu KB\n",
538 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
539 pr_debug("max write behind: %u\n", le32_to_cpu(sb->write_behind));
540 kunmap_atomic(sb);
541}
542
543/*
544 * bitmap_new_disk_sb
545 * @bitmap
546 *
547 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
548 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
549 * This function verifies 'bitmap_info' and populates the on-disk bitmap
550 * structure, which is to be written to disk.
551 *
552 * Returns: 0 on success, -Exxx on error
553 */
554static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
555{
556 bitmap_super_t *sb;
557 unsigned long chunksize, daemon_sleep, write_behind;
558
559 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
560 if (bitmap->storage.sb_page == NULL)
561 return -ENOMEM;
562 bitmap->storage.sb_index = 0;
563
564 sb = kmap_atomic(bitmap->storage.sb_page);
565
566 sb->magic = cpu_to_le32(BITMAP_MAGIC);
567 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
568
569 chunksize = bitmap->mddev->bitmap_info.chunksize;
570 BUG_ON(!chunksize);
571 if (!is_power_of_2(chunksize)) {
572 kunmap_atomic(sb);
573 pr_warn("bitmap chunksize not a power of 2\n");
574 return -EINVAL;
575 }
576 sb->chunksize = cpu_to_le32(chunksize);
577
578 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
579 if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
580 pr_debug("Choosing daemon_sleep default (5 sec)\n");
581 daemon_sleep = 5 * HZ;
582 }
583 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
584 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
585
586 /*
587 * FIXME: write_behind for RAID1. If not specified, what
588 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
589 */
590 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
591 if (write_behind > COUNTER_MAX)
592 write_behind = COUNTER_MAX / 2;
593 sb->write_behind = cpu_to_le32(write_behind);
594 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
595
596 /* keep the array size field of the bitmap superblock up to date */
597 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
598
599 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
600
601 set_bit(BITMAP_STALE, &bitmap->flags);
602 sb->state = cpu_to_le32(bitmap->flags);
603 bitmap->events_cleared = bitmap->mddev->events;
604 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
605 bitmap->mddev->bitmap_info.nodes = 0;
606
607 kunmap_atomic(sb);
608
609 return 0;
610}
611
612/* read the superblock from the bitmap file and initialize some bitmap fields */
613static int md_bitmap_read_sb(struct bitmap *bitmap)
614{
615 char *reason = NULL;
616 bitmap_super_t *sb;
617 unsigned long chunksize, daemon_sleep, write_behind;
618 unsigned long long events;
619 int nodes = 0;
620 unsigned long sectors_reserved = 0;
621 int err = -EINVAL;
622 struct page *sb_page;
623 loff_t offset = 0;
624
625 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
626 chunksize = 128 * 1024 * 1024;
627 daemon_sleep = 5 * HZ;
628 write_behind = 0;
629 set_bit(BITMAP_STALE, &bitmap->flags);
630 err = 0;
631 goto out_no_sb;
632 }
633 /* page 0 is the superblock, read it... */
634 sb_page = alloc_page(GFP_KERNEL);
635 if (!sb_page)
636 return -ENOMEM;
637 bitmap->storage.sb_page = sb_page;
638
639re_read:
640 /* If cluster_slot is set, the cluster is setup */
641 if (bitmap->cluster_slot >= 0) {
642 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
643
644 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks,
645 (bitmap->mddev->bitmap_info.chunksize >> 9));
646 /* bits to bytes */
647 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
648 /* to 4k blocks */
649 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
650 offset = bitmap->cluster_slot * (bm_blocks << 3);
651 pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
652 bitmap->cluster_slot, offset);
653 }
654
655 if (bitmap->storage.file) {
656 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
657 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
658
659 err = read_file_page(bitmap->storage.file, 0,
660 bitmap, bytes, sb_page);
661 } else {
662 err = read_sb_page(bitmap->mddev, offset, sb_page, 0,
663 sizeof(bitmap_super_t));
664 }
665 if (err)
666 return err;
667
668 err = -EINVAL;
669 sb = kmap_atomic(sb_page);
670
671 chunksize = le32_to_cpu(sb->chunksize);
672 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
673 write_behind = le32_to_cpu(sb->write_behind);
674 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
675
676 /* verify that the bitmap-specific fields are valid */
677 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
678 reason = "bad magic";
679 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
680 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
681 reason = "unrecognized superblock version";
682 else if (chunksize < 512)
683 reason = "bitmap chunksize too small";
684 else if (!is_power_of_2(chunksize))
685 reason = "bitmap chunksize not a power of 2";
686 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
687 reason = "daemon sleep period out of range";
688 else if (write_behind > COUNTER_MAX)
689 reason = "write-behind limit out of range (0 - 16383)";
690 if (reason) {
691 pr_warn("%s: invalid bitmap file superblock: %s\n",
692 bmname(bitmap), reason);
693 goto out;
694 }
695
696 /*
697 * Setup nodes/clustername only if bitmap version is
698 * cluster-compatible
699 */
700 if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
701 nodes = le32_to_cpu(sb->nodes);
702 strscpy(bitmap->mddev->bitmap_info.cluster_name,
703 sb->cluster_name, 64);
704 }
705
706 /* keep the array size field of the bitmap superblock up to date */
707 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
708
709 if (bitmap->mddev->persistent) {
710 /*
711 * We have a persistent array superblock, so compare the
712 * bitmap's UUID and event counter to the mddev's
713 */
714 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
715 pr_warn("%s: bitmap superblock UUID mismatch\n",
716 bmname(bitmap));
717 goto out;
718 }
719 events = le64_to_cpu(sb->events);
720 if (!nodes && (events < bitmap->mddev->events)) {
721 pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
722 bmname(bitmap), events,
723 (unsigned long long) bitmap->mddev->events);
724 set_bit(BITMAP_STALE, &bitmap->flags);
725 }
726 }
727
728 /* assign fields using values from superblock */
729 bitmap->flags |= le32_to_cpu(sb->state);
730 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
731 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
732 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
733 err = 0;
734
735out:
736 kunmap_atomic(sb);
737 if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
738 /* Assigning chunksize is required for "re_read" */
739 bitmap->mddev->bitmap_info.chunksize = chunksize;
740 err = md_setup_cluster(bitmap->mddev, nodes);
741 if (err) {
742 pr_warn("%s: Could not setup cluster service (%d)\n",
743 bmname(bitmap), err);
744 goto out_no_sb;
745 }
746 bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
747 goto re_read;
748 }
749
750out_no_sb:
751 if (err == 0) {
752 if (test_bit(BITMAP_STALE, &bitmap->flags))
753 bitmap->events_cleared = bitmap->mddev->events;
754 bitmap->mddev->bitmap_info.chunksize = chunksize;
755 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
756 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
757 bitmap->mddev->bitmap_info.nodes = nodes;
758 if (bitmap->mddev->bitmap_info.space == 0 ||
759 bitmap->mddev->bitmap_info.space > sectors_reserved)
760 bitmap->mddev->bitmap_info.space = sectors_reserved;
761 } else {
762 md_bitmap_print_sb(bitmap);
763 if (bitmap->cluster_slot < 0)
764 md_cluster_stop(bitmap->mddev);
765 }
766 return err;
767}
768
769/*
770 * general bitmap file operations
771 */
772
773/*
774 * on-disk bitmap:
775 *
776 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
777 * file a page at a time. There's a superblock at the start of the file.
778 */
779/* calculate the index of the page that contains this bit */
780static inline unsigned long file_page_index(struct bitmap_storage *store,
781 unsigned long chunk)
782{
783 if (store->sb_page)
784 chunk += sizeof(bitmap_super_t) << 3;
785 return chunk >> PAGE_BIT_SHIFT;
786}
787
788/* calculate the (bit) offset of this bit within a page */
789static inline unsigned long file_page_offset(struct bitmap_storage *store,
790 unsigned long chunk)
791{
792 if (store->sb_page)
793 chunk += sizeof(bitmap_super_t) << 3;
794 return chunk & (PAGE_BITS - 1);
795}
796
797/*
798 * return a pointer to the page in the filemap that contains the given bit
799 *
800 */
801static inline struct page *filemap_get_page(struct bitmap_storage *store,
802 unsigned long chunk)
803{
804 if (file_page_index(store, chunk) >= store->file_pages)
805 return NULL;
806 return store->filemap[file_page_index(store, chunk)];
807}
808
809static int md_bitmap_storage_alloc(struct bitmap_storage *store,
810 unsigned long chunks, int with_super,
811 int slot_number)
812{
813 int pnum, offset = 0;
814 unsigned long num_pages;
815 unsigned long bytes;
816
817 bytes = DIV_ROUND_UP(chunks, 8);
818 if (with_super)
819 bytes += sizeof(bitmap_super_t);
820
821 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
822 offset = slot_number * num_pages;
823
824 store->filemap = kmalloc_array(num_pages, sizeof(struct page *),
825 GFP_KERNEL);
826 if (!store->filemap)
827 return -ENOMEM;
828
829 if (with_super && !store->sb_page) {
830 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
831 if (store->sb_page == NULL)
832 return -ENOMEM;
833 }
834
835 pnum = 0;
836 if (store->sb_page) {
837 store->filemap[0] = store->sb_page;
838 pnum = 1;
839 store->sb_index = offset;
840 }
841
842 for ( ; pnum < num_pages; pnum++) {
843 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
844 if (!store->filemap[pnum]) {
845 store->file_pages = pnum;
846 return -ENOMEM;
847 }
848 }
849 store->file_pages = pnum;
850
851 /* We need 4 bits per page, rounded up to a multiple
852 * of sizeof(unsigned long) */
853 store->filemap_attr = kzalloc(
854 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
855 GFP_KERNEL);
856 if (!store->filemap_attr)
857 return -ENOMEM;
858
859 store->bytes = bytes;
860
861 return 0;
862}
863
864static void md_bitmap_file_unmap(struct bitmap_storage *store)
865{
866 struct file *file = store->file;
867 struct page *sb_page = store->sb_page;
868 struct page **map = store->filemap;
869 int pages = store->file_pages;
870
871 while (pages--)
872 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
873 free_buffers(map[pages]);
874 kfree(map);
875 kfree(store->filemap_attr);
876
877 if (sb_page)
878 free_buffers(sb_page);
879
880 if (file) {
881 struct inode *inode = file_inode(file);
882 invalidate_mapping_pages(inode->i_mapping, 0, -1);
883 fput(file);
884 }
885}
886
887/*
888 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
889 * then it is no longer reliable, so we stop using it and we mark the file
890 * as failed in the superblock
891 */
892static void md_bitmap_file_kick(struct bitmap *bitmap)
893{
894 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
895 md_bitmap_update_sb(bitmap);
896
897 if (bitmap->storage.file) {
898 pr_warn("%s: kicking failed bitmap file %pD4 from array!\n",
899 bmname(bitmap), bitmap->storage.file);
900
901 } else
902 pr_warn("%s: disabling internal bitmap due to errors\n",
903 bmname(bitmap));
904 }
905}
906
907enum bitmap_page_attr {
908 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
909 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
910 * i.e. counter is 1 or 2. */
911 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
912};
913
914static inline void set_page_attr(struct bitmap *bitmap, int pnum,
915 enum bitmap_page_attr attr)
916{
917 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
918}
919
920static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
921 enum bitmap_page_attr attr)
922{
923 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
924}
925
926static inline int test_page_attr(struct bitmap *bitmap, int pnum,
927 enum bitmap_page_attr attr)
928{
929 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
930}
931
932static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
933 enum bitmap_page_attr attr)
934{
935 return test_and_clear_bit((pnum<<2) + attr,
936 bitmap->storage.filemap_attr);
937}
938/*
939 * bitmap_file_set_bit -- called before performing a write to the md device
940 * to set (and eventually sync) a particular bit in the bitmap file
941 *
942 * we set the bit immediately, then we record the page number so that
943 * when an unplug occurs, we can flush the dirty pages out to disk
944 */
945static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
946{
947 unsigned long bit;
948 struct page *page;
949 void *kaddr;
950 unsigned long chunk = block >> bitmap->counts.chunkshift;
951 struct bitmap_storage *store = &bitmap->storage;
952 unsigned long index = file_page_index(store, chunk);
953 unsigned long node_offset = 0;
954
955 if (mddev_is_clustered(bitmap->mddev))
956 node_offset = bitmap->cluster_slot * store->file_pages;
957
958 page = filemap_get_page(&bitmap->storage, chunk);
959 if (!page)
960 return;
961 bit = file_page_offset(&bitmap->storage, chunk);
962
963 /* set the bit */
964 kaddr = kmap_atomic(page);
965 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
966 set_bit(bit, kaddr);
967 else
968 set_bit_le(bit, kaddr);
969 kunmap_atomic(kaddr);
970 pr_debug("set file bit %lu page %lu\n", bit, index);
971 /* record page number so it gets flushed to disk when unplug occurs */
972 set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_DIRTY);
973}
974
975static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
976{
977 unsigned long bit;
978 struct page *page;
979 void *paddr;
980 unsigned long chunk = block >> bitmap->counts.chunkshift;
981 struct bitmap_storage *store = &bitmap->storage;
982 unsigned long index = file_page_index(store, chunk);
983 unsigned long node_offset = 0;
984
985 if (mddev_is_clustered(bitmap->mddev))
986 node_offset = bitmap->cluster_slot * store->file_pages;
987
988 page = filemap_get_page(&bitmap->storage, chunk);
989 if (!page)
990 return;
991 bit = file_page_offset(&bitmap->storage, chunk);
992 paddr = kmap_atomic(page);
993 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
994 clear_bit(bit, paddr);
995 else
996 clear_bit_le(bit, paddr);
997 kunmap_atomic(paddr);
998 if (!test_page_attr(bitmap, index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
999 set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_PENDING);
1000 bitmap->allclean = 0;
1001 }
1002}
1003
1004static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
1005{
1006 unsigned long bit;
1007 struct page *page;
1008 void *paddr;
1009 unsigned long chunk = block >> bitmap->counts.chunkshift;
1010 int set = 0;
1011
1012 page = filemap_get_page(&bitmap->storage, chunk);
1013 if (!page)
1014 return -EINVAL;
1015 bit = file_page_offset(&bitmap->storage, chunk);
1016 paddr = kmap_atomic(page);
1017 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1018 set = test_bit(bit, paddr);
1019 else
1020 set = test_bit_le(bit, paddr);
1021 kunmap_atomic(paddr);
1022 return set;
1023}
1024
1025/* this gets called when the md device is ready to unplug its underlying
1026 * (slave) device queues -- before we let any writes go down, we need to
1027 * sync the dirty pages of the bitmap file to disk */
1028void md_bitmap_unplug(struct bitmap *bitmap)
1029{
1030 unsigned long i;
1031 int dirty, need_write;
1032 int writing = 0;
1033
1034 if (!md_bitmap_enabled(bitmap))
1035 return;
1036
1037 /* look at each page to see if there are any set bits that need to be
1038 * flushed out to disk */
1039 for (i = 0; i < bitmap->storage.file_pages; i++) {
1040 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1041 need_write = test_and_clear_page_attr(bitmap, i,
1042 BITMAP_PAGE_NEEDWRITE);
1043 if (dirty || need_write) {
1044 if (!writing) {
1045 md_bitmap_wait_writes(bitmap);
1046 if (bitmap->mddev->queue)
1047 blk_add_trace_msg(bitmap->mddev->queue,
1048 "md bitmap_unplug");
1049 }
1050 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
1051 filemap_write_page(bitmap, i, false);
1052 writing = 1;
1053 }
1054 }
1055 if (writing)
1056 md_bitmap_wait_writes(bitmap);
1057
1058 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1059 md_bitmap_file_kick(bitmap);
1060}
1061EXPORT_SYMBOL(md_bitmap_unplug);
1062
1063struct bitmap_unplug_work {
1064 struct work_struct work;
1065 struct bitmap *bitmap;
1066 struct completion *done;
1067};
1068
1069static void md_bitmap_unplug_fn(struct work_struct *work)
1070{
1071 struct bitmap_unplug_work *unplug_work =
1072 container_of(work, struct bitmap_unplug_work, work);
1073
1074 md_bitmap_unplug(unplug_work->bitmap);
1075 complete(unplug_work->done);
1076}
1077
1078void md_bitmap_unplug_async(struct bitmap *bitmap)
1079{
1080 DECLARE_COMPLETION_ONSTACK(done);
1081 struct bitmap_unplug_work unplug_work;
1082
1083 INIT_WORK_ONSTACK(&unplug_work.work, md_bitmap_unplug_fn);
1084 unplug_work.bitmap = bitmap;
1085 unplug_work.done = &done;
1086
1087 queue_work(md_bitmap_wq, &unplug_work.work);
1088 wait_for_completion(&done);
1089}
1090EXPORT_SYMBOL(md_bitmap_unplug_async);
1091
1092static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1093
1094/*
1095 * Initialize the in-memory bitmap from the on-disk bitmap and set up the memory
1096 * mapping of the bitmap file.
1097 *
1098 * Special case: If there's no bitmap file, or if the bitmap file had been
1099 * previously kicked from the array, we mark all the bits as 1's in order to
1100 * cause a full resync.
1101 *
1102 * We ignore all bits for sectors that end earlier than 'start'.
1103 * This is used when reading an out-of-date bitmap.
1104 */
1105static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1106{
1107 bool outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1108 struct mddev *mddev = bitmap->mddev;
1109 unsigned long chunks = bitmap->counts.chunks;
1110 struct bitmap_storage *store = &bitmap->storage;
1111 struct file *file = store->file;
1112 unsigned long node_offset = 0;
1113 unsigned long bit_cnt = 0;
1114 unsigned long i;
1115 int ret;
1116
1117 if (!file && !mddev->bitmap_info.offset) {
1118 /* No permanent bitmap - fill with '1s'. */
1119 store->filemap = NULL;
1120 store->file_pages = 0;
1121 for (i = 0; i < chunks ; i++) {
1122 /* if the disk bit is set, set the memory bit */
1123 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1124 >= start);
1125 md_bitmap_set_memory_bits(bitmap,
1126 (sector_t)i << bitmap->counts.chunkshift,
1127 needed);
1128 }
1129 return 0;
1130 }
1131
1132 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
1133 pr_warn("%s: bitmap file too short %lu < %lu\n",
1134 bmname(bitmap),
1135 (unsigned long) i_size_read(file->f_mapping->host),
1136 store->bytes);
1137 ret = -ENOSPC;
1138 goto err;
1139 }
1140
1141 if (mddev_is_clustered(mddev))
1142 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1143
1144 for (i = 0; i < store->file_pages; i++) {
1145 struct page *page = store->filemap[i];
1146 int count;
1147
1148 /* unmap the old page, we're done with it */
1149 if (i == store->file_pages - 1)
1150 count = store->bytes - i * PAGE_SIZE;
1151 else
1152 count = PAGE_SIZE;
1153
1154 if (file)
1155 ret = read_file_page(file, i, bitmap, count, page);
1156 else
1157 ret = read_sb_page(mddev, 0, page, i + node_offset,
1158 count);
1159 if (ret)
1160 goto err;
1161 }
1162
1163 if (outofdate) {
1164 pr_warn("%s: bitmap file is out of date, doing full recovery\n",
1165 bmname(bitmap));
1166
1167 for (i = 0; i < store->file_pages; i++) {
1168 struct page *page = store->filemap[i];
1169 unsigned long offset = 0;
1170 void *paddr;
1171
1172 if (i == 0 && !mddev->bitmap_info.external)
1173 offset = sizeof(bitmap_super_t);
1174
1175 /*
1176 * If the bitmap is out of date, dirty the whole page
1177 * and write it out
1178 */
1179 paddr = kmap_atomic(page);
1180 memset(paddr + offset, 0xff, PAGE_SIZE - offset);
1181 kunmap_atomic(paddr);
1182
1183 filemap_write_page(bitmap, i, true);
1184 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags)) {
1185 ret = -EIO;
1186 goto err;
1187 }
1188 }
1189 }
1190
1191 for (i = 0; i < chunks; i++) {
1192 struct page *page = filemap_get_page(&bitmap->storage, i);
1193 unsigned long bit = file_page_offset(&bitmap->storage, i);
1194 void *paddr;
1195 bool was_set;
1196
1197 paddr = kmap_atomic(page);
1198 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1199 was_set = test_bit(bit, paddr);
1200 else
1201 was_set = test_bit_le(bit, paddr);
1202 kunmap_atomic(paddr);
1203
1204 if (was_set) {
1205 /* if the disk bit is set, set the memory bit */
1206 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1207 >= start);
1208 md_bitmap_set_memory_bits(bitmap,
1209 (sector_t)i << bitmap->counts.chunkshift,
1210 needed);
1211 bit_cnt++;
1212 }
1213 }
1214
1215 pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
1216 bmname(bitmap), store->file_pages,
1217 bit_cnt, chunks);
1218
1219 return 0;
1220
1221 err:
1222 pr_warn("%s: bitmap initialisation failed: %d\n",
1223 bmname(bitmap), ret);
1224 return ret;
1225}
1226
1227void md_bitmap_write_all(struct bitmap *bitmap)
1228{
1229 /* We don't actually write all bitmap blocks here,
1230 * just flag them as needing to be written
1231 */
1232 int i;
1233
1234 if (!bitmap || !bitmap->storage.filemap)
1235 return;
1236 if (bitmap->storage.file)
1237 /* Only one copy, so nothing needed */
1238 return;
1239
1240 for (i = 0; i < bitmap->storage.file_pages; i++)
1241 set_page_attr(bitmap, i,
1242 BITMAP_PAGE_NEEDWRITE);
1243 bitmap->allclean = 0;
1244}
1245
1246static void md_bitmap_count_page(struct bitmap_counts *bitmap,
1247 sector_t offset, int inc)
1248{
1249 sector_t chunk = offset >> bitmap->chunkshift;
1250 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1251 bitmap->bp[page].count += inc;
1252 md_bitmap_checkfree(bitmap, page);
1253}
1254
1255static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1256{
1257 sector_t chunk = offset >> bitmap->chunkshift;
1258 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1259 struct bitmap_page *bp = &bitmap->bp[page];
1260
1261 if (!bp->pending)
1262 bp->pending = 1;
1263}
1264
1265static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1266 sector_t offset, sector_t *blocks,
1267 int create);
1268
1269static void mddev_set_timeout(struct mddev *mddev, unsigned long timeout,
1270 bool force)
1271{
1272 struct md_thread *thread;
1273
1274 rcu_read_lock();
1275 thread = rcu_dereference(mddev->thread);
1276
1277 if (!thread)
1278 goto out;
1279
1280 if (force || thread->timeout < MAX_SCHEDULE_TIMEOUT)
1281 thread->timeout = timeout;
1282
1283out:
1284 rcu_read_unlock();
1285}
1286
1287/*
1288 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1289 * out to disk
1290 */
1291void md_bitmap_daemon_work(struct mddev *mddev)
1292{
1293 struct bitmap *bitmap;
1294 unsigned long j;
1295 unsigned long nextpage;
1296 sector_t blocks;
1297 struct bitmap_counts *counts;
1298
1299 /* Use a mutex to guard daemon_work against
1300 * bitmap_destroy.
1301 */
1302 mutex_lock(&mddev->bitmap_info.mutex);
1303 bitmap = mddev->bitmap;
1304 if (bitmap == NULL) {
1305 mutex_unlock(&mddev->bitmap_info.mutex);
1306 return;
1307 }
1308 if (time_before(jiffies, bitmap->daemon_lastrun
1309 + mddev->bitmap_info.daemon_sleep))
1310 goto done;
1311
1312 bitmap->daemon_lastrun = jiffies;
1313 if (bitmap->allclean) {
1314 mddev_set_timeout(mddev, MAX_SCHEDULE_TIMEOUT, true);
1315 goto done;
1316 }
1317 bitmap->allclean = 1;
1318
1319 if (bitmap->mddev->queue)
1320 blk_add_trace_msg(bitmap->mddev->queue,
1321 "md bitmap_daemon_work");
1322
1323 /* Any file-page which is PENDING now needs to be written.
1324 * So set NEEDWRITE now, then after we make any last-minute changes
1325 * we will write it.
1326 */
1327 for (j = 0; j < bitmap->storage.file_pages; j++)
1328 if (test_and_clear_page_attr(bitmap, j,
1329 BITMAP_PAGE_PENDING))
1330 set_page_attr(bitmap, j,
1331 BITMAP_PAGE_NEEDWRITE);
1332
1333 if (bitmap->need_sync &&
1334 mddev->bitmap_info.external == 0) {
1335 /* Arrange for superblock update as well as
1336 * other changes */
1337 bitmap_super_t *sb;
1338 bitmap->need_sync = 0;
1339 if (bitmap->storage.filemap) {
1340 sb = kmap_atomic(bitmap->storage.sb_page);
1341 sb->events_cleared =
1342 cpu_to_le64(bitmap->events_cleared);
1343 kunmap_atomic(sb);
1344 set_page_attr(bitmap, 0,
1345 BITMAP_PAGE_NEEDWRITE);
1346 }
1347 }
1348 /* Now look at the bitmap counters and if any are '2' or '1',
1349 * decrement and handle accordingly.
1350 */
1351 counts = &bitmap->counts;
1352 spin_lock_irq(&counts->lock);
1353 nextpage = 0;
1354 for (j = 0; j < counts->chunks; j++) {
1355 bitmap_counter_t *bmc;
1356 sector_t block = (sector_t)j << counts->chunkshift;
1357
1358 if (j == nextpage) {
1359 nextpage += PAGE_COUNTER_RATIO;
1360 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1361 j |= PAGE_COUNTER_MASK;
1362 continue;
1363 }
1364 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1365 }
1366
1367 bmc = md_bitmap_get_counter(counts, block, &blocks, 0);
1368 if (!bmc) {
1369 j |= PAGE_COUNTER_MASK;
1370 continue;
1371 }
1372 if (*bmc == 1 && !bitmap->need_sync) {
1373 /* We can clear the bit */
1374 *bmc = 0;
1375 md_bitmap_count_page(counts, block, -1);
1376 md_bitmap_file_clear_bit(bitmap, block);
1377 } else if (*bmc && *bmc <= 2) {
1378 *bmc = 1;
1379 md_bitmap_set_pending(counts, block);
1380 bitmap->allclean = 0;
1381 }
1382 }
1383 spin_unlock_irq(&counts->lock);
1384
1385 md_bitmap_wait_writes(bitmap);
1386 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1387 * DIRTY pages need to be written by bitmap_unplug so it can wait
1388 * for them.
1389 * If we find any DIRTY page we stop there and let bitmap_unplug
1390 * handle all the rest. This is important in the case where
1391 * the first blocking holds the superblock and it has been updated.
1392 * We mustn't write any other blocks before the superblock.
1393 */
1394 for (j = 0;
1395 j < bitmap->storage.file_pages
1396 && !test_bit(BITMAP_STALE, &bitmap->flags);
1397 j++) {
1398 if (test_page_attr(bitmap, j,
1399 BITMAP_PAGE_DIRTY))
1400 /* bitmap_unplug will handle the rest */
1401 break;
1402 if (bitmap->storage.filemap &&
1403 test_and_clear_page_attr(bitmap, j,
1404 BITMAP_PAGE_NEEDWRITE))
1405 filemap_write_page(bitmap, j, false);
1406 }
1407
1408 done:
1409 if (bitmap->allclean == 0)
1410 mddev_set_timeout(mddev, mddev->bitmap_info.daemon_sleep, true);
1411 mutex_unlock(&mddev->bitmap_info.mutex);
1412}
1413
1414static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1415 sector_t offset, sector_t *blocks,
1416 int create)
1417__releases(bitmap->lock)
1418__acquires(bitmap->lock)
1419{
1420 /* If 'create', we might release the lock and reclaim it.
1421 * The lock must have been taken with interrupts enabled.
1422 * If !create, we don't release the lock.
1423 */
1424 sector_t chunk = offset >> bitmap->chunkshift;
1425 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1426 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1427 sector_t csize;
1428 int err;
1429
1430 if (page >= bitmap->pages) {
1431 /*
1432 * This can happen if bitmap_start_sync goes beyond
1433 * End-of-device while looking for a whole page or
1434 * user set a huge number to sysfs bitmap_set_bits.
1435 */
1436 return NULL;
1437 }
1438 err = md_bitmap_checkpage(bitmap, page, create, 0);
1439
1440 if (bitmap->bp[page].hijacked ||
1441 bitmap->bp[page].map == NULL)
1442 csize = ((sector_t)1) << (bitmap->chunkshift +
1443 PAGE_COUNTER_SHIFT);
1444 else
1445 csize = ((sector_t)1) << bitmap->chunkshift;
1446 *blocks = csize - (offset & (csize - 1));
1447
1448 if (err < 0)
1449 return NULL;
1450
1451 /* now locked ... */
1452
1453 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1454 /* should we use the first or second counter field
1455 * of the hijacked pointer? */
1456 int hi = (pageoff > PAGE_COUNTER_MASK);
1457 return &((bitmap_counter_t *)
1458 &bitmap->bp[page].map)[hi];
1459 } else /* page is allocated */
1460 return (bitmap_counter_t *)
1461 &(bitmap->bp[page].map[pageoff]);
1462}
1463
1464int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1465{
1466 if (!bitmap)
1467 return 0;
1468
1469 if (behind) {
1470 int bw;
1471 atomic_inc(&bitmap->behind_writes);
1472 bw = atomic_read(&bitmap->behind_writes);
1473 if (bw > bitmap->behind_writes_used)
1474 bitmap->behind_writes_used = bw;
1475
1476 pr_debug("inc write-behind count %d/%lu\n",
1477 bw, bitmap->mddev->bitmap_info.max_write_behind);
1478 }
1479
1480 while (sectors) {
1481 sector_t blocks;
1482 bitmap_counter_t *bmc;
1483
1484 spin_lock_irq(&bitmap->counts.lock);
1485 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1486 if (!bmc) {
1487 spin_unlock_irq(&bitmap->counts.lock);
1488 return 0;
1489 }
1490
1491 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1492 DEFINE_WAIT(__wait);
1493 /* note that it is safe to do the prepare_to_wait
1494 * after the test as long as we do it before dropping
1495 * the spinlock.
1496 */
1497 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1498 TASK_UNINTERRUPTIBLE);
1499 spin_unlock_irq(&bitmap->counts.lock);
1500 schedule();
1501 finish_wait(&bitmap->overflow_wait, &__wait);
1502 continue;
1503 }
1504
1505 switch (*bmc) {
1506 case 0:
1507 md_bitmap_file_set_bit(bitmap, offset);
1508 md_bitmap_count_page(&bitmap->counts, offset, 1);
1509 fallthrough;
1510 case 1:
1511 *bmc = 2;
1512 }
1513
1514 (*bmc)++;
1515
1516 spin_unlock_irq(&bitmap->counts.lock);
1517
1518 offset += blocks;
1519 if (sectors > blocks)
1520 sectors -= blocks;
1521 else
1522 sectors = 0;
1523 }
1524 return 0;
1525}
1526EXPORT_SYMBOL(md_bitmap_startwrite);
1527
1528void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
1529 unsigned long sectors, int success, int behind)
1530{
1531 if (!bitmap)
1532 return;
1533 if (behind) {
1534 if (atomic_dec_and_test(&bitmap->behind_writes))
1535 wake_up(&bitmap->behind_wait);
1536 pr_debug("dec write-behind count %d/%lu\n",
1537 atomic_read(&bitmap->behind_writes),
1538 bitmap->mddev->bitmap_info.max_write_behind);
1539 }
1540
1541 while (sectors) {
1542 sector_t blocks;
1543 unsigned long flags;
1544 bitmap_counter_t *bmc;
1545
1546 spin_lock_irqsave(&bitmap->counts.lock, flags);
1547 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1548 if (!bmc) {
1549 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1550 return;
1551 }
1552
1553 if (success && !bitmap->mddev->degraded &&
1554 bitmap->events_cleared < bitmap->mddev->events) {
1555 bitmap->events_cleared = bitmap->mddev->events;
1556 bitmap->need_sync = 1;
1557 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1558 }
1559
1560 if (!success && !NEEDED(*bmc))
1561 *bmc |= NEEDED_MASK;
1562
1563 if (COUNTER(*bmc) == COUNTER_MAX)
1564 wake_up(&bitmap->overflow_wait);
1565
1566 (*bmc)--;
1567 if (*bmc <= 2) {
1568 md_bitmap_set_pending(&bitmap->counts, offset);
1569 bitmap->allclean = 0;
1570 }
1571 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1572 offset += blocks;
1573 if (sectors > blocks)
1574 sectors -= blocks;
1575 else
1576 sectors = 0;
1577 }
1578}
1579EXPORT_SYMBOL(md_bitmap_endwrite);
1580
1581static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1582 int degraded)
1583{
1584 bitmap_counter_t *bmc;
1585 int rv;
1586 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1587 *blocks = 1024;
1588 return 1; /* always resync if no bitmap */
1589 }
1590 spin_lock_irq(&bitmap->counts.lock);
1591 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1592 rv = 0;
1593 if (bmc) {
1594 /* locked */
1595 if (RESYNC(*bmc))
1596 rv = 1;
1597 else if (NEEDED(*bmc)) {
1598 rv = 1;
1599 if (!degraded) { /* don't set/clear bits if degraded */
1600 *bmc |= RESYNC_MASK;
1601 *bmc &= ~NEEDED_MASK;
1602 }
1603 }
1604 }
1605 spin_unlock_irq(&bitmap->counts.lock);
1606 return rv;
1607}
1608
1609int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1610 int degraded)
1611{
1612 /* bitmap_start_sync must always report on multiples of whole
1613 * pages, otherwise resync (which is very PAGE_SIZE based) will
1614 * get confused.
1615 * So call __bitmap_start_sync repeatedly (if needed) until
1616 * At least PAGE_SIZE>>9 blocks are covered.
1617 * Return the 'or' of the result.
1618 */
1619 int rv = 0;
1620 sector_t blocks1;
1621
1622 *blocks = 0;
1623 while (*blocks < (PAGE_SIZE>>9)) {
1624 rv |= __bitmap_start_sync(bitmap, offset,
1625 &blocks1, degraded);
1626 offset += blocks1;
1627 *blocks += blocks1;
1628 }
1629 return rv;
1630}
1631EXPORT_SYMBOL(md_bitmap_start_sync);
1632
1633void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1634{
1635 bitmap_counter_t *bmc;
1636 unsigned long flags;
1637
1638 if (bitmap == NULL) {
1639 *blocks = 1024;
1640 return;
1641 }
1642 spin_lock_irqsave(&bitmap->counts.lock, flags);
1643 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1644 if (bmc == NULL)
1645 goto unlock;
1646 /* locked */
1647 if (RESYNC(*bmc)) {
1648 *bmc &= ~RESYNC_MASK;
1649
1650 if (!NEEDED(*bmc) && aborted)
1651 *bmc |= NEEDED_MASK;
1652 else {
1653 if (*bmc <= 2) {
1654 md_bitmap_set_pending(&bitmap->counts, offset);
1655 bitmap->allclean = 0;
1656 }
1657 }
1658 }
1659 unlock:
1660 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1661}
1662EXPORT_SYMBOL(md_bitmap_end_sync);
1663
1664void md_bitmap_close_sync(struct bitmap *bitmap)
1665{
1666 /* Sync has finished, and any bitmap chunks that weren't synced
1667 * properly have been aborted. It remains to us to clear the
1668 * RESYNC bit wherever it is still on
1669 */
1670 sector_t sector = 0;
1671 sector_t blocks;
1672 if (!bitmap)
1673 return;
1674 while (sector < bitmap->mddev->resync_max_sectors) {
1675 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1676 sector += blocks;
1677 }
1678}
1679EXPORT_SYMBOL(md_bitmap_close_sync);
1680
1681void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
1682{
1683 sector_t s = 0;
1684 sector_t blocks;
1685
1686 if (!bitmap)
1687 return;
1688 if (sector == 0) {
1689 bitmap->last_end_sync = jiffies;
1690 return;
1691 }
1692 if (!force && time_before(jiffies, (bitmap->last_end_sync
1693 + bitmap->mddev->bitmap_info.daemon_sleep)))
1694 return;
1695 wait_event(bitmap->mddev->recovery_wait,
1696 atomic_read(&bitmap->mddev->recovery_active) == 0);
1697
1698 bitmap->mddev->curr_resync_completed = sector;
1699 set_bit(MD_SB_CHANGE_CLEAN, &bitmap->mddev->sb_flags);
1700 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1701 s = 0;
1702 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1703 md_bitmap_end_sync(bitmap, s, &blocks, 0);
1704 s += blocks;
1705 }
1706 bitmap->last_end_sync = jiffies;
1707 sysfs_notify_dirent_safe(bitmap->mddev->sysfs_completed);
1708}
1709EXPORT_SYMBOL(md_bitmap_cond_end_sync);
1710
1711void md_bitmap_sync_with_cluster(struct mddev *mddev,
1712 sector_t old_lo, sector_t old_hi,
1713 sector_t new_lo, sector_t new_hi)
1714{
1715 struct bitmap *bitmap = mddev->bitmap;
1716 sector_t sector, blocks = 0;
1717
1718 for (sector = old_lo; sector < new_lo; ) {
1719 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1720 sector += blocks;
1721 }
1722 WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
1723
1724 for (sector = old_hi; sector < new_hi; ) {
1725 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1726 sector += blocks;
1727 }
1728 WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
1729}
1730EXPORT_SYMBOL(md_bitmap_sync_with_cluster);
1731
1732static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1733{
1734 /* For each chunk covered by any of these sectors, set the
1735 * counter to 2 and possibly set resync_needed. They should all
1736 * be 0 at this point
1737 */
1738
1739 sector_t secs;
1740 bitmap_counter_t *bmc;
1741 spin_lock_irq(&bitmap->counts.lock);
1742 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1743 if (!bmc) {
1744 spin_unlock_irq(&bitmap->counts.lock);
1745 return;
1746 }
1747 if (!*bmc) {
1748 *bmc = 2;
1749 md_bitmap_count_page(&bitmap->counts, offset, 1);
1750 md_bitmap_set_pending(&bitmap->counts, offset);
1751 bitmap->allclean = 0;
1752 }
1753 if (needed)
1754 *bmc |= NEEDED_MASK;
1755 spin_unlock_irq(&bitmap->counts.lock);
1756}
1757
1758/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1759void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1760{
1761 unsigned long chunk;
1762
1763 for (chunk = s; chunk <= e; chunk++) {
1764 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1765 md_bitmap_set_memory_bits(bitmap, sec, 1);
1766 md_bitmap_file_set_bit(bitmap, sec);
1767 if (sec < bitmap->mddev->recovery_cp)
1768 /* We are asserting that the array is dirty,
1769 * so move the recovery_cp address back so
1770 * that it is obvious that it is dirty
1771 */
1772 bitmap->mddev->recovery_cp = sec;
1773 }
1774}
1775
1776/*
1777 * flush out any pending updates
1778 */
1779void md_bitmap_flush(struct mddev *mddev)
1780{
1781 struct bitmap *bitmap = mddev->bitmap;
1782 long sleep;
1783
1784 if (!bitmap) /* there was no bitmap */
1785 return;
1786
1787 /* run the daemon_work three time to ensure everything is flushed
1788 * that can be
1789 */
1790 sleep = mddev->bitmap_info.daemon_sleep * 2;
1791 bitmap->daemon_lastrun -= sleep;
1792 md_bitmap_daemon_work(mddev);
1793 bitmap->daemon_lastrun -= sleep;
1794 md_bitmap_daemon_work(mddev);
1795 bitmap->daemon_lastrun -= sleep;
1796 md_bitmap_daemon_work(mddev);
1797 if (mddev->bitmap_info.external)
1798 md_super_wait(mddev);
1799 md_bitmap_update_sb(bitmap);
1800}
1801
1802/*
1803 * free memory that was allocated
1804 */
1805void md_bitmap_free(struct bitmap *bitmap)
1806{
1807 unsigned long k, pages;
1808 struct bitmap_page *bp;
1809
1810 if (!bitmap) /* there was no bitmap */
1811 return;
1812
1813 if (bitmap->sysfs_can_clear)
1814 sysfs_put(bitmap->sysfs_can_clear);
1815
1816 if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
1817 bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
1818 md_cluster_stop(bitmap->mddev);
1819
1820 /* Shouldn't be needed - but just in case.... */
1821 wait_event(bitmap->write_wait,
1822 atomic_read(&bitmap->pending_writes) == 0);
1823
1824 /* release the bitmap file */
1825 md_bitmap_file_unmap(&bitmap->storage);
1826
1827 bp = bitmap->counts.bp;
1828 pages = bitmap->counts.pages;
1829
1830 /* free all allocated memory */
1831
1832 if (bp) /* deallocate the page memory */
1833 for (k = 0; k < pages; k++)
1834 if (bp[k].map && !bp[k].hijacked)
1835 kfree(bp[k].map);
1836 kfree(bp);
1837 kfree(bitmap);
1838}
1839EXPORT_SYMBOL(md_bitmap_free);
1840
1841void md_bitmap_wait_behind_writes(struct mddev *mddev)
1842{
1843 struct bitmap *bitmap = mddev->bitmap;
1844
1845 /* wait for behind writes to complete */
1846 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1847 pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
1848 mdname(mddev));
1849 /* need to kick something here to make sure I/O goes? */
1850 wait_event(bitmap->behind_wait,
1851 atomic_read(&bitmap->behind_writes) == 0);
1852 }
1853}
1854
1855void md_bitmap_destroy(struct mddev *mddev)
1856{
1857 struct bitmap *bitmap = mddev->bitmap;
1858
1859 if (!bitmap) /* there was no bitmap */
1860 return;
1861
1862 md_bitmap_wait_behind_writes(mddev);
1863 if (!mddev->serialize_policy)
1864 mddev_destroy_serial_pool(mddev, NULL);
1865
1866 mutex_lock(&mddev->bitmap_info.mutex);
1867 spin_lock(&mddev->lock);
1868 mddev->bitmap = NULL; /* disconnect from the md device */
1869 spin_unlock(&mddev->lock);
1870 mutex_unlock(&mddev->bitmap_info.mutex);
1871 mddev_set_timeout(mddev, MAX_SCHEDULE_TIMEOUT, true);
1872
1873 md_bitmap_free(bitmap);
1874}
1875
1876/*
1877 * initialize the bitmap structure
1878 * if this returns an error, bitmap_destroy must be called to do clean up
1879 * once mddev->bitmap is set
1880 */
1881struct bitmap *md_bitmap_create(struct mddev *mddev, int slot)
1882{
1883 struct bitmap *bitmap;
1884 sector_t blocks = mddev->resync_max_sectors;
1885 struct file *file = mddev->bitmap_info.file;
1886 int err;
1887 struct kernfs_node *bm = NULL;
1888
1889 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1890
1891 BUG_ON(file && mddev->bitmap_info.offset);
1892
1893 if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
1894 pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
1895 mdname(mddev));
1896 return ERR_PTR(-EBUSY);
1897 }
1898
1899 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1900 if (!bitmap)
1901 return ERR_PTR(-ENOMEM);
1902
1903 spin_lock_init(&bitmap->counts.lock);
1904 atomic_set(&bitmap->pending_writes, 0);
1905 init_waitqueue_head(&bitmap->write_wait);
1906 init_waitqueue_head(&bitmap->overflow_wait);
1907 init_waitqueue_head(&bitmap->behind_wait);
1908
1909 bitmap->mddev = mddev;
1910 bitmap->cluster_slot = slot;
1911
1912 if (mddev->kobj.sd)
1913 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
1914 if (bm) {
1915 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
1916 sysfs_put(bm);
1917 } else
1918 bitmap->sysfs_can_clear = NULL;
1919
1920 bitmap->storage.file = file;
1921 if (file) {
1922 get_file(file);
1923 /* As future accesses to this file will use bmap,
1924 * and bypass the page cache, we must sync the file
1925 * first.
1926 */
1927 vfs_fsync(file, 1);
1928 }
1929 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1930 if (!mddev->bitmap_info.external) {
1931 /*
1932 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1933 * instructing us to create a new on-disk bitmap instance.
1934 */
1935 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1936 err = md_bitmap_new_disk_sb(bitmap);
1937 else
1938 err = md_bitmap_read_sb(bitmap);
1939 } else {
1940 err = 0;
1941 if (mddev->bitmap_info.chunksize == 0 ||
1942 mddev->bitmap_info.daemon_sleep == 0)
1943 /* chunksize and time_base need to be
1944 * set first. */
1945 err = -EINVAL;
1946 }
1947 if (err)
1948 goto error;
1949
1950 bitmap->daemon_lastrun = jiffies;
1951 err = md_bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1952 if (err)
1953 goto error;
1954
1955 pr_debug("created bitmap (%lu pages) for device %s\n",
1956 bitmap->counts.pages, bmname(bitmap));
1957
1958 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1959 if (err)
1960 goto error;
1961
1962 return bitmap;
1963 error:
1964 md_bitmap_free(bitmap);
1965 return ERR_PTR(err);
1966}
1967
1968int md_bitmap_load(struct mddev *mddev)
1969{
1970 int err = 0;
1971 sector_t start = 0;
1972 sector_t sector = 0;
1973 struct bitmap *bitmap = mddev->bitmap;
1974 struct md_rdev *rdev;
1975
1976 if (!bitmap)
1977 goto out;
1978
1979 rdev_for_each(rdev, mddev)
1980 mddev_create_serial_pool(mddev, rdev);
1981
1982 if (mddev_is_clustered(mddev))
1983 md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
1984
1985 /* Clear out old bitmap info first: Either there is none, or we
1986 * are resuming after someone else has possibly changed things,
1987 * so we should forget old cached info.
1988 * All chunks should be clean, but some might need_sync.
1989 */
1990 while (sector < mddev->resync_max_sectors) {
1991 sector_t blocks;
1992 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1993 sector += blocks;
1994 }
1995 md_bitmap_close_sync(bitmap);
1996
1997 if (mddev->degraded == 0
1998 || bitmap->events_cleared == mddev->events)
1999 /* no need to keep dirty bits to optimise a
2000 * re-add of a missing device */
2001 start = mddev->recovery_cp;
2002
2003 mutex_lock(&mddev->bitmap_info.mutex);
2004 err = md_bitmap_init_from_disk(bitmap, start);
2005 mutex_unlock(&mddev->bitmap_info.mutex);
2006
2007 if (err)
2008 goto out;
2009 clear_bit(BITMAP_STALE, &bitmap->flags);
2010
2011 /* Kick recovery in case any bits were set */
2012 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
2013
2014 mddev_set_timeout(mddev, mddev->bitmap_info.daemon_sleep, true);
2015 md_wakeup_thread(mddev->thread);
2016
2017 md_bitmap_update_sb(bitmap);
2018
2019 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
2020 err = -EIO;
2021out:
2022 return err;
2023}
2024EXPORT_SYMBOL_GPL(md_bitmap_load);
2025
2026/* caller need to free returned bitmap with md_bitmap_free() */
2027struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
2028{
2029 int rv = 0;
2030 struct bitmap *bitmap;
2031
2032 bitmap = md_bitmap_create(mddev, slot);
2033 if (IS_ERR(bitmap)) {
2034 rv = PTR_ERR(bitmap);
2035 return ERR_PTR(rv);
2036 }
2037
2038 rv = md_bitmap_init_from_disk(bitmap, 0);
2039 if (rv) {
2040 md_bitmap_free(bitmap);
2041 return ERR_PTR(rv);
2042 }
2043
2044 return bitmap;
2045}
2046EXPORT_SYMBOL(get_bitmap_from_slot);
2047
2048/* Loads the bitmap associated with slot and copies the resync information
2049 * to our bitmap
2050 */
2051int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
2052 sector_t *low, sector_t *high, bool clear_bits)
2053{
2054 int rv = 0, i, j;
2055 sector_t block, lo = 0, hi = 0;
2056 struct bitmap_counts *counts;
2057 struct bitmap *bitmap;
2058
2059 bitmap = get_bitmap_from_slot(mddev, slot);
2060 if (IS_ERR(bitmap)) {
2061 pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
2062 return -1;
2063 }
2064
2065 counts = &bitmap->counts;
2066 for (j = 0; j < counts->chunks; j++) {
2067 block = (sector_t)j << counts->chunkshift;
2068 if (md_bitmap_file_test_bit(bitmap, block)) {
2069 if (!lo)
2070 lo = block;
2071 hi = block;
2072 md_bitmap_file_clear_bit(bitmap, block);
2073 md_bitmap_set_memory_bits(mddev->bitmap, block, 1);
2074 md_bitmap_file_set_bit(mddev->bitmap, block);
2075 }
2076 }
2077
2078 if (clear_bits) {
2079 md_bitmap_update_sb(bitmap);
2080 /* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
2081 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
2082 for (i = 0; i < bitmap->storage.file_pages; i++)
2083 if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
2084 set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
2085 md_bitmap_unplug(bitmap);
2086 }
2087 md_bitmap_unplug(mddev->bitmap);
2088 *low = lo;
2089 *high = hi;
2090 md_bitmap_free(bitmap);
2091
2092 return rv;
2093}
2094EXPORT_SYMBOL_GPL(md_bitmap_copy_from_slot);
2095
2096
2097void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
2098{
2099 unsigned long chunk_kb;
2100 struct bitmap_counts *counts;
2101
2102 if (!bitmap)
2103 return;
2104
2105 counts = &bitmap->counts;
2106
2107 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
2108 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
2109 "%lu%s chunk",
2110 counts->pages - counts->missing_pages,
2111 counts->pages,
2112 (counts->pages - counts->missing_pages)
2113 << (PAGE_SHIFT - 10),
2114 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
2115 chunk_kb ? "KB" : "B");
2116 if (bitmap->storage.file) {
2117 seq_printf(seq, ", file: ");
2118 seq_file_path(seq, bitmap->storage.file, " \t\n");
2119 }
2120
2121 seq_printf(seq, "\n");
2122}
2123
2124int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
2125 int chunksize, int init)
2126{
2127 /* If chunk_size is 0, choose an appropriate chunk size.
2128 * Then possibly allocate new storage space.
2129 * Then quiesce, copy bits, replace bitmap, and re-start
2130 *
2131 * This function is called both to set up the initial bitmap
2132 * and to resize the bitmap while the array is active.
2133 * If this happens as a result of the array being resized,
2134 * chunksize will be zero, and we need to choose a suitable
2135 * chunksize, otherwise we use what we are given.
2136 */
2137 struct bitmap_storage store;
2138 struct bitmap_counts old_counts;
2139 unsigned long chunks;
2140 sector_t block;
2141 sector_t old_blocks, new_blocks;
2142 int chunkshift;
2143 int ret = 0;
2144 long pages;
2145 struct bitmap_page *new_bp;
2146
2147 if (bitmap->storage.file && !init) {
2148 pr_info("md: cannot resize file-based bitmap\n");
2149 return -EINVAL;
2150 }
2151
2152 if (chunksize == 0) {
2153 /* If there is enough space, leave the chunk size unchanged,
2154 * else increase by factor of two until there is enough space.
2155 */
2156 long bytes;
2157 long space = bitmap->mddev->bitmap_info.space;
2158
2159 if (space == 0) {
2160 /* We don't know how much space there is, so limit
2161 * to current size - in sectors.
2162 */
2163 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
2164 if (!bitmap->mddev->bitmap_info.external)
2165 bytes += sizeof(bitmap_super_t);
2166 space = DIV_ROUND_UP(bytes, 512);
2167 bitmap->mddev->bitmap_info.space = space;
2168 }
2169 chunkshift = bitmap->counts.chunkshift;
2170 chunkshift--;
2171 do {
2172 /* 'chunkshift' is shift from block size to chunk size */
2173 chunkshift++;
2174 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2175 bytes = DIV_ROUND_UP(chunks, 8);
2176 if (!bitmap->mddev->bitmap_info.external)
2177 bytes += sizeof(bitmap_super_t);
2178 } while (bytes > (space << 9) && (chunkshift + BITMAP_BLOCK_SHIFT) <
2179 (BITS_PER_BYTE * sizeof(((bitmap_super_t *)0)->chunksize) - 1));
2180 } else
2181 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
2182
2183 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2184 memset(&store, 0, sizeof(store));
2185 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2186 ret = md_bitmap_storage_alloc(&store, chunks,
2187 !bitmap->mddev->bitmap_info.external,
2188 mddev_is_clustered(bitmap->mddev)
2189 ? bitmap->cluster_slot : 0);
2190 if (ret) {
2191 md_bitmap_file_unmap(&store);
2192 goto err;
2193 }
2194
2195 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2196
2197 new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
2198 ret = -ENOMEM;
2199 if (!new_bp) {
2200 md_bitmap_file_unmap(&store);
2201 goto err;
2202 }
2203
2204 if (!init)
2205 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2206
2207 store.file = bitmap->storage.file;
2208 bitmap->storage.file = NULL;
2209
2210 if (store.sb_page && bitmap->storage.sb_page)
2211 memcpy(page_address(store.sb_page),
2212 page_address(bitmap->storage.sb_page),
2213 sizeof(bitmap_super_t));
2214 spin_lock_irq(&bitmap->counts.lock);
2215 md_bitmap_file_unmap(&bitmap->storage);
2216 bitmap->storage = store;
2217
2218 old_counts = bitmap->counts;
2219 bitmap->counts.bp = new_bp;
2220 bitmap->counts.pages = pages;
2221 bitmap->counts.missing_pages = pages;
2222 bitmap->counts.chunkshift = chunkshift;
2223 bitmap->counts.chunks = chunks;
2224 bitmap->mddev->bitmap_info.chunksize = 1UL << (chunkshift +
2225 BITMAP_BLOCK_SHIFT);
2226
2227 blocks = min(old_counts.chunks << old_counts.chunkshift,
2228 chunks << chunkshift);
2229
2230 /* For cluster raid, need to pre-allocate bitmap */
2231 if (mddev_is_clustered(bitmap->mddev)) {
2232 unsigned long page;
2233 for (page = 0; page < pages; page++) {
2234 ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1);
2235 if (ret) {
2236 unsigned long k;
2237
2238 /* deallocate the page memory */
2239 for (k = 0; k < page; k++) {
2240 kfree(new_bp[k].map);
2241 }
2242 kfree(new_bp);
2243
2244 /* restore some fields from old_counts */
2245 bitmap->counts.bp = old_counts.bp;
2246 bitmap->counts.pages = old_counts.pages;
2247 bitmap->counts.missing_pages = old_counts.pages;
2248 bitmap->counts.chunkshift = old_counts.chunkshift;
2249 bitmap->counts.chunks = old_counts.chunks;
2250 bitmap->mddev->bitmap_info.chunksize =
2251 1UL << (old_counts.chunkshift + BITMAP_BLOCK_SHIFT);
2252 blocks = old_counts.chunks << old_counts.chunkshift;
2253 pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
2254 break;
2255 } else
2256 bitmap->counts.bp[page].count += 1;
2257 }
2258 }
2259
2260 for (block = 0; block < blocks; ) {
2261 bitmap_counter_t *bmc_old, *bmc_new;
2262 int set;
2263
2264 bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0);
2265 set = bmc_old && NEEDED(*bmc_old);
2266
2267 if (set) {
2268 bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2269 if (bmc_new) {
2270 if (*bmc_new == 0) {
2271 /* need to set on-disk bits too. */
2272 sector_t end = block + new_blocks;
2273 sector_t start = block >> chunkshift;
2274
2275 start <<= chunkshift;
2276 while (start < end) {
2277 md_bitmap_file_set_bit(bitmap, block);
2278 start += 1 << chunkshift;
2279 }
2280 *bmc_new = 2;
2281 md_bitmap_count_page(&bitmap->counts, block, 1);
2282 md_bitmap_set_pending(&bitmap->counts, block);
2283 }
2284 *bmc_new |= NEEDED_MASK;
2285 }
2286 if (new_blocks < old_blocks)
2287 old_blocks = new_blocks;
2288 }
2289 block += old_blocks;
2290 }
2291
2292 if (bitmap->counts.bp != old_counts.bp) {
2293 unsigned long k;
2294 for (k = 0; k < old_counts.pages; k++)
2295 if (!old_counts.bp[k].hijacked)
2296 kfree(old_counts.bp[k].map);
2297 kfree(old_counts.bp);
2298 }
2299
2300 if (!init) {
2301 int i;
2302 while (block < (chunks << chunkshift)) {
2303 bitmap_counter_t *bmc;
2304 bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2305 if (bmc) {
2306 /* new space. It needs to be resynced, so
2307 * we set NEEDED_MASK.
2308 */
2309 if (*bmc == 0) {
2310 *bmc = NEEDED_MASK | 2;
2311 md_bitmap_count_page(&bitmap->counts, block, 1);
2312 md_bitmap_set_pending(&bitmap->counts, block);
2313 }
2314 }
2315 block += new_blocks;
2316 }
2317 for (i = 0; i < bitmap->storage.file_pages; i++)
2318 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
2319 }
2320 spin_unlock_irq(&bitmap->counts.lock);
2321
2322 if (!init) {
2323 md_bitmap_unplug(bitmap);
2324 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2325 }
2326 ret = 0;
2327err:
2328 return ret;
2329}
2330EXPORT_SYMBOL_GPL(md_bitmap_resize);
2331
2332static ssize_t
2333location_show(struct mddev *mddev, char *page)
2334{
2335 ssize_t len;
2336 if (mddev->bitmap_info.file)
2337 len = sprintf(page, "file");
2338 else if (mddev->bitmap_info.offset)
2339 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
2340 else
2341 len = sprintf(page, "none");
2342 len += sprintf(page+len, "\n");
2343 return len;
2344}
2345
2346static ssize_t
2347location_store(struct mddev *mddev, const char *buf, size_t len)
2348{
2349 int rv;
2350
2351 rv = mddev_suspend_and_lock(mddev);
2352 if (rv)
2353 return rv;
2354
2355 if (mddev->pers) {
2356 if (mddev->recovery || mddev->sync_thread) {
2357 rv = -EBUSY;
2358 goto out;
2359 }
2360 }
2361
2362 if (mddev->bitmap || mddev->bitmap_info.file ||
2363 mddev->bitmap_info.offset) {
2364 /* bitmap already configured. Only option is to clear it */
2365 if (strncmp(buf, "none", 4) != 0) {
2366 rv = -EBUSY;
2367 goto out;
2368 }
2369
2370 md_bitmap_destroy(mddev);
2371 mddev->bitmap_info.offset = 0;
2372 if (mddev->bitmap_info.file) {
2373 struct file *f = mddev->bitmap_info.file;
2374 mddev->bitmap_info.file = NULL;
2375 fput(f);
2376 }
2377 } else {
2378 /* No bitmap, OK to set a location */
2379 long long offset;
2380 struct bitmap *bitmap;
2381
2382 if (strncmp(buf, "none", 4) == 0)
2383 /* nothing to be done */;
2384 else if (strncmp(buf, "file:", 5) == 0) {
2385 /* Not supported yet */
2386 rv = -EINVAL;
2387 goto out;
2388 } else {
2389 if (buf[0] == '+')
2390 rv = kstrtoll(buf+1, 10, &offset);
2391 else
2392 rv = kstrtoll(buf, 10, &offset);
2393 if (rv)
2394 goto out;
2395 if (offset == 0) {
2396 rv = -EINVAL;
2397 goto out;
2398 }
2399 if (mddev->bitmap_info.external == 0 &&
2400 mddev->major_version == 0 &&
2401 offset != mddev->bitmap_info.default_offset) {
2402 rv = -EINVAL;
2403 goto out;
2404 }
2405
2406 mddev->bitmap_info.offset = offset;
2407 bitmap = md_bitmap_create(mddev, -1);
2408 if (IS_ERR(bitmap)) {
2409 rv = PTR_ERR(bitmap);
2410 goto out;
2411 }
2412
2413 mddev->bitmap = bitmap;
2414 rv = md_bitmap_load(mddev);
2415 if (rv) {
2416 mddev->bitmap_info.offset = 0;
2417 md_bitmap_destroy(mddev);
2418 goto out;
2419 }
2420 }
2421 }
2422 if (!mddev->external) {
2423 /* Ensure new bitmap info is stored in
2424 * metadata promptly.
2425 */
2426 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2427 md_wakeup_thread(mddev->thread);
2428 }
2429 rv = 0;
2430out:
2431 mddev_unlock_and_resume(mddev);
2432 if (rv)
2433 return rv;
2434 return len;
2435}
2436
2437static struct md_sysfs_entry bitmap_location =
2438__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2439
2440/* 'bitmap/space' is the space available at 'location' for the
2441 * bitmap. This allows the kernel to know when it is safe to
2442 * resize the bitmap to match a resized array.
2443 */
2444static ssize_t
2445space_show(struct mddev *mddev, char *page)
2446{
2447 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2448}
2449
2450static ssize_t
2451space_store(struct mddev *mddev, const char *buf, size_t len)
2452{
2453 unsigned long sectors;
2454 int rv;
2455
2456 rv = kstrtoul(buf, 10, §ors);
2457 if (rv)
2458 return rv;
2459
2460 if (sectors == 0)
2461 return -EINVAL;
2462
2463 if (mddev->bitmap &&
2464 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2465 return -EFBIG; /* Bitmap is too big for this small space */
2466
2467 /* could make sure it isn't too big, but that isn't really
2468 * needed - user-space should be careful.
2469 */
2470 mddev->bitmap_info.space = sectors;
2471 return len;
2472}
2473
2474static struct md_sysfs_entry bitmap_space =
2475__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2476
2477static ssize_t
2478timeout_show(struct mddev *mddev, char *page)
2479{
2480 ssize_t len;
2481 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2482 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2483
2484 len = sprintf(page, "%lu", secs);
2485 if (jifs)
2486 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2487 len += sprintf(page+len, "\n");
2488 return len;
2489}
2490
2491static ssize_t
2492timeout_store(struct mddev *mddev, const char *buf, size_t len)
2493{
2494 /* timeout can be set at any time */
2495 unsigned long timeout;
2496 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2497 if (rv)
2498 return rv;
2499
2500 /* just to make sure we don't overflow... */
2501 if (timeout >= LONG_MAX / HZ)
2502 return -EINVAL;
2503
2504 timeout = timeout * HZ / 10000;
2505
2506 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2507 timeout = MAX_SCHEDULE_TIMEOUT-1;
2508 if (timeout < 1)
2509 timeout = 1;
2510
2511 mddev->bitmap_info.daemon_sleep = timeout;
2512 mddev_set_timeout(mddev, timeout, false);
2513 md_wakeup_thread(mddev->thread);
2514
2515 return len;
2516}
2517
2518static struct md_sysfs_entry bitmap_timeout =
2519__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2520
2521static ssize_t
2522backlog_show(struct mddev *mddev, char *page)
2523{
2524 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2525}
2526
2527static ssize_t
2528backlog_store(struct mddev *mddev, const char *buf, size_t len)
2529{
2530 unsigned long backlog;
2531 unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
2532 struct md_rdev *rdev;
2533 bool has_write_mostly = false;
2534 int rv = kstrtoul(buf, 10, &backlog);
2535 if (rv)
2536 return rv;
2537 if (backlog > COUNTER_MAX)
2538 return -EINVAL;
2539
2540 rv = mddev_suspend_and_lock(mddev);
2541 if (rv)
2542 return rv;
2543
2544 /*
2545 * Without write mostly device, it doesn't make sense to set
2546 * backlog for max_write_behind.
2547 */
2548 rdev_for_each(rdev, mddev) {
2549 if (test_bit(WriteMostly, &rdev->flags)) {
2550 has_write_mostly = true;
2551 break;
2552 }
2553 }
2554 if (!has_write_mostly) {
2555 pr_warn_ratelimited("%s: can't set backlog, no write mostly device available\n",
2556 mdname(mddev));
2557 mddev_unlock(mddev);
2558 return -EINVAL;
2559 }
2560
2561 mddev->bitmap_info.max_write_behind = backlog;
2562 if (!backlog && mddev->serial_info_pool) {
2563 /* serial_info_pool is not needed if backlog is zero */
2564 if (!mddev->serialize_policy)
2565 mddev_destroy_serial_pool(mddev, NULL);
2566 } else if (backlog && !mddev->serial_info_pool) {
2567 /* serial_info_pool is needed since backlog is not zero */
2568 rdev_for_each(rdev, mddev)
2569 mddev_create_serial_pool(mddev, rdev);
2570 }
2571 if (old_mwb != backlog)
2572 md_bitmap_update_sb(mddev->bitmap);
2573
2574 mddev_unlock_and_resume(mddev);
2575 return len;
2576}
2577
2578static struct md_sysfs_entry bitmap_backlog =
2579__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2580
2581static ssize_t
2582chunksize_show(struct mddev *mddev, char *page)
2583{
2584 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2585}
2586
2587static ssize_t
2588chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2589{
2590 /* Can only be changed when no bitmap is active */
2591 int rv;
2592 unsigned long csize;
2593 if (mddev->bitmap)
2594 return -EBUSY;
2595 rv = kstrtoul(buf, 10, &csize);
2596 if (rv)
2597 return rv;
2598 if (csize < 512 ||
2599 !is_power_of_2(csize))
2600 return -EINVAL;
2601 if (BITS_PER_LONG > 32 && csize >= (1ULL << (BITS_PER_BYTE *
2602 sizeof(((bitmap_super_t *)0)->chunksize))))
2603 return -EOVERFLOW;
2604 mddev->bitmap_info.chunksize = csize;
2605 return len;
2606}
2607
2608static struct md_sysfs_entry bitmap_chunksize =
2609__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2610
2611static ssize_t metadata_show(struct mddev *mddev, char *page)
2612{
2613 if (mddev_is_clustered(mddev))
2614 return sprintf(page, "clustered\n");
2615 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2616 ? "external" : "internal"));
2617}
2618
2619static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2620{
2621 if (mddev->bitmap ||
2622 mddev->bitmap_info.file ||
2623 mddev->bitmap_info.offset)
2624 return -EBUSY;
2625 if (strncmp(buf, "external", 8) == 0)
2626 mddev->bitmap_info.external = 1;
2627 else if ((strncmp(buf, "internal", 8) == 0) ||
2628 (strncmp(buf, "clustered", 9) == 0))
2629 mddev->bitmap_info.external = 0;
2630 else
2631 return -EINVAL;
2632 return len;
2633}
2634
2635static struct md_sysfs_entry bitmap_metadata =
2636__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2637
2638static ssize_t can_clear_show(struct mddev *mddev, char *page)
2639{
2640 int len;
2641 spin_lock(&mddev->lock);
2642 if (mddev->bitmap)
2643 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2644 "false" : "true"));
2645 else
2646 len = sprintf(page, "\n");
2647 spin_unlock(&mddev->lock);
2648 return len;
2649}
2650
2651static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2652{
2653 if (mddev->bitmap == NULL)
2654 return -ENOENT;
2655 if (strncmp(buf, "false", 5) == 0)
2656 mddev->bitmap->need_sync = 1;
2657 else if (strncmp(buf, "true", 4) == 0) {
2658 if (mddev->degraded)
2659 return -EBUSY;
2660 mddev->bitmap->need_sync = 0;
2661 } else
2662 return -EINVAL;
2663 return len;
2664}
2665
2666static struct md_sysfs_entry bitmap_can_clear =
2667__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2668
2669static ssize_t
2670behind_writes_used_show(struct mddev *mddev, char *page)
2671{
2672 ssize_t ret;
2673 spin_lock(&mddev->lock);
2674 if (mddev->bitmap == NULL)
2675 ret = sprintf(page, "0\n");
2676 else
2677 ret = sprintf(page, "%lu\n",
2678 mddev->bitmap->behind_writes_used);
2679 spin_unlock(&mddev->lock);
2680 return ret;
2681}
2682
2683static ssize_t
2684behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2685{
2686 if (mddev->bitmap)
2687 mddev->bitmap->behind_writes_used = 0;
2688 return len;
2689}
2690
2691static struct md_sysfs_entry max_backlog_used =
2692__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2693 behind_writes_used_show, behind_writes_used_reset);
2694
2695static struct attribute *md_bitmap_attrs[] = {
2696 &bitmap_location.attr,
2697 &bitmap_space.attr,
2698 &bitmap_timeout.attr,
2699 &bitmap_backlog.attr,
2700 &bitmap_chunksize.attr,
2701 &bitmap_metadata.attr,
2702 &bitmap_can_clear.attr,
2703 &max_backlog_used.attr,
2704 NULL
2705};
2706const struct attribute_group md_bitmap_group = {
2707 .name = "bitmap",
2708 .attrs = md_bitmap_attrs,
2709};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
4 *
5 * bitmap_create - sets up the bitmap structure
6 * bitmap_destroy - destroys the bitmap structure
7 *
8 * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
9 * - added disk storage for bitmap
10 * - changes to allow various bitmap chunk sizes
11 */
12
13/*
14 * Still to do:
15 *
16 * flush after percent set rather than just time based. (maybe both).
17 */
18
19#include <linux/blkdev.h>
20#include <linux/module.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/init.h>
24#include <linux/timer.h>
25#include <linux/sched.h>
26#include <linux/list.h>
27#include <linux/file.h>
28#include <linux/mount.h>
29#include <linux/buffer_head.h>
30#include <linux/seq_file.h>
31#include <trace/events/block.h>
32#include "md.h"
33#include "md-bitmap.h"
34
35static inline char *bmname(struct bitmap *bitmap)
36{
37 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
38}
39
40/*
41 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
42 *
43 * 1) check to see if this page is allocated, if it's not then try to alloc
44 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
45 * page pointer directly as a counter
46 *
47 * if we find our page, we increment the page's refcount so that it stays
48 * allocated while we're using it
49 */
50static int md_bitmap_checkpage(struct bitmap_counts *bitmap,
51 unsigned long page, int create, int no_hijack)
52__releases(bitmap->lock)
53__acquires(bitmap->lock)
54{
55 unsigned char *mappage;
56
57 if (page >= bitmap->pages) {
58 /* This can happen if bitmap_start_sync goes beyond
59 * End-of-device while looking for a whole page.
60 * It is harmless.
61 */
62 return -EINVAL;
63 }
64
65 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
66 return 0;
67
68 if (bitmap->bp[page].map) /* page is already allocated, just return */
69 return 0;
70
71 if (!create)
72 return -ENOENT;
73
74 /* this page has not been allocated yet */
75
76 spin_unlock_irq(&bitmap->lock);
77 /* It is possible that this is being called inside a
78 * prepare_to_wait/finish_wait loop from raid5c:make_request().
79 * In general it is not permitted to sleep in that context as it
80 * can cause the loop to spin freely.
81 * That doesn't apply here as we can only reach this point
82 * once with any loop.
83 * When this function completes, either bp[page].map or
84 * bp[page].hijacked. In either case, this function will
85 * abort before getting to this point again. So there is
86 * no risk of a free-spin, and so it is safe to assert
87 * that sleeping here is allowed.
88 */
89 sched_annotate_sleep();
90 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
91 spin_lock_irq(&bitmap->lock);
92
93 if (mappage == NULL) {
94 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
95 /* We don't support hijack for cluster raid */
96 if (no_hijack)
97 return -ENOMEM;
98 /* failed - set the hijacked flag so that we can use the
99 * pointer as a counter */
100 if (!bitmap->bp[page].map)
101 bitmap->bp[page].hijacked = 1;
102 } else if (bitmap->bp[page].map ||
103 bitmap->bp[page].hijacked) {
104 /* somebody beat us to getting the page */
105 kfree(mappage);
106 } else {
107
108 /* no page was in place and we have one, so install it */
109
110 bitmap->bp[page].map = mappage;
111 bitmap->missing_pages--;
112 }
113 return 0;
114}
115
116/* if page is completely empty, put it back on the free list, or dealloc it */
117/* if page was hijacked, unmark the flag so it might get alloced next time */
118/* Note: lock should be held when calling this */
119static void md_bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
120{
121 char *ptr;
122
123 if (bitmap->bp[page].count) /* page is still busy */
124 return;
125
126 /* page is no longer in use, it can be released */
127
128 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
129 bitmap->bp[page].hijacked = 0;
130 bitmap->bp[page].map = NULL;
131 } else {
132 /* normal case, free the page */
133 ptr = bitmap->bp[page].map;
134 bitmap->bp[page].map = NULL;
135 bitmap->missing_pages++;
136 kfree(ptr);
137 }
138}
139
140/*
141 * bitmap file handling - read and write the bitmap file and its superblock
142 */
143
144/*
145 * basic page I/O operations
146 */
147
148/* IO operations when bitmap is stored near all superblocks */
149static int read_sb_page(struct mddev *mddev, loff_t offset,
150 struct page *page,
151 unsigned long index, int size)
152{
153 /* choose a good rdev and read the page from there */
154
155 struct md_rdev *rdev;
156 sector_t target;
157
158 rdev_for_each(rdev, mddev) {
159 if (! test_bit(In_sync, &rdev->flags)
160 || test_bit(Faulty, &rdev->flags)
161 || test_bit(Bitmap_sync, &rdev->flags))
162 continue;
163
164 target = offset + index * (PAGE_SIZE/512);
165
166 if (sync_page_io(rdev, target,
167 roundup(size, bdev_logical_block_size(rdev->bdev)),
168 page, REQ_OP_READ, 0, true)) {
169 page->index = index;
170 return 0;
171 }
172 }
173 return -EIO;
174}
175
176static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
177{
178 /* Iterate the disks of an mddev, using rcu to protect access to the
179 * linked list, and raising the refcount of devices we return to ensure
180 * they don't disappear while in use.
181 * As devices are only added or removed when raid_disk is < 0 and
182 * nr_pending is 0 and In_sync is clear, the entries we return will
183 * still be in the same position on the list when we re-enter
184 * list_for_each_entry_continue_rcu.
185 *
186 * Note that if entered with 'rdev == NULL' to start at the
187 * beginning, we temporarily assign 'rdev' to an address which
188 * isn't really an rdev, but which can be used by
189 * list_for_each_entry_continue_rcu() to find the first entry.
190 */
191 rcu_read_lock();
192 if (rdev == NULL)
193 /* start at the beginning */
194 rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
195 else {
196 /* release the previous rdev and start from there. */
197 rdev_dec_pending(rdev, mddev);
198 }
199 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
200 if (rdev->raid_disk >= 0 &&
201 !test_bit(Faulty, &rdev->flags)) {
202 /* this is a usable devices */
203 atomic_inc(&rdev->nr_pending);
204 rcu_read_unlock();
205 return rdev;
206 }
207 }
208 rcu_read_unlock();
209 return NULL;
210}
211
212static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
213{
214 struct md_rdev *rdev;
215 struct block_device *bdev;
216 struct mddev *mddev = bitmap->mddev;
217 struct bitmap_storage *store = &bitmap->storage;
218
219restart:
220 rdev = NULL;
221 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
222 int size = PAGE_SIZE;
223 loff_t offset = mddev->bitmap_info.offset;
224
225 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
226
227 if (page->index == store->file_pages-1) {
228 int last_page_size = store->bytes & (PAGE_SIZE-1);
229 if (last_page_size == 0)
230 last_page_size = PAGE_SIZE;
231 size = roundup(last_page_size,
232 bdev_logical_block_size(bdev));
233 }
234 /* Just make sure we aren't corrupting data or
235 * metadata
236 */
237 if (mddev->external) {
238 /* Bitmap could be anywhere. */
239 if (rdev->sb_start + offset + (page->index
240 * (PAGE_SIZE/512))
241 > rdev->data_offset
242 &&
243 rdev->sb_start + offset
244 < (rdev->data_offset + mddev->dev_sectors
245 + (PAGE_SIZE/512)))
246 goto bad_alignment;
247 } else if (offset < 0) {
248 /* DATA BITMAP METADATA */
249 if (offset
250 + (long)(page->index * (PAGE_SIZE/512))
251 + size/512 > 0)
252 /* bitmap runs in to metadata */
253 goto bad_alignment;
254 if (rdev->data_offset + mddev->dev_sectors
255 > rdev->sb_start + offset)
256 /* data runs in to bitmap */
257 goto bad_alignment;
258 } else if (rdev->sb_start < rdev->data_offset) {
259 /* METADATA BITMAP DATA */
260 if (rdev->sb_start
261 + offset
262 + page->index*(PAGE_SIZE/512) + size/512
263 > rdev->data_offset)
264 /* bitmap runs in to data */
265 goto bad_alignment;
266 } else {
267 /* DATA METADATA BITMAP - no problems */
268 }
269 md_super_write(mddev, rdev,
270 rdev->sb_start + offset
271 + page->index * (PAGE_SIZE/512),
272 size,
273 page);
274 }
275
276 if (wait && md_super_wait(mddev) < 0)
277 goto restart;
278 return 0;
279
280 bad_alignment:
281 return -EINVAL;
282}
283
284static void md_bitmap_file_kick(struct bitmap *bitmap);
285/*
286 * write out a page to a file
287 */
288static void write_page(struct bitmap *bitmap, struct page *page, int wait)
289{
290 struct buffer_head *bh;
291
292 if (bitmap->storage.file == NULL) {
293 switch (write_sb_page(bitmap, page, wait)) {
294 case -EINVAL:
295 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
296 }
297 } else {
298
299 bh = page_buffers(page);
300
301 while (bh && bh->b_blocknr) {
302 atomic_inc(&bitmap->pending_writes);
303 set_buffer_locked(bh);
304 set_buffer_mapped(bh);
305 submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
306 bh = bh->b_this_page;
307 }
308
309 if (wait)
310 wait_event(bitmap->write_wait,
311 atomic_read(&bitmap->pending_writes)==0);
312 }
313 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
314 md_bitmap_file_kick(bitmap);
315}
316
317static void end_bitmap_write(struct buffer_head *bh, int uptodate)
318{
319 struct bitmap *bitmap = bh->b_private;
320
321 if (!uptodate)
322 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
323 if (atomic_dec_and_test(&bitmap->pending_writes))
324 wake_up(&bitmap->write_wait);
325}
326
327/* copied from buffer.c */
328static void
329__clear_page_buffers(struct page *page)
330{
331 ClearPagePrivate(page);
332 set_page_private(page, 0);
333 put_page(page);
334}
335static void free_buffers(struct page *page)
336{
337 struct buffer_head *bh;
338
339 if (!PagePrivate(page))
340 return;
341
342 bh = page_buffers(page);
343 while (bh) {
344 struct buffer_head *next = bh->b_this_page;
345 free_buffer_head(bh);
346 bh = next;
347 }
348 __clear_page_buffers(page);
349 put_page(page);
350}
351
352/* read a page from a file.
353 * We both read the page, and attach buffers to the page to record the
354 * address of each block (using bmap). These addresses will be used
355 * to write the block later, completely bypassing the filesystem.
356 * This usage is similar to how swap files are handled, and allows us
357 * to write to a file with no concerns of memory allocation failing.
358 */
359static int read_page(struct file *file, unsigned long index,
360 struct bitmap *bitmap,
361 unsigned long count,
362 struct page *page)
363{
364 int ret = 0;
365 struct inode *inode = file_inode(file);
366 struct buffer_head *bh;
367 sector_t block;
368
369 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
370 (unsigned long long)index << PAGE_SHIFT);
371
372 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, false);
373 if (!bh) {
374 ret = -ENOMEM;
375 goto out;
376 }
377 attach_page_buffers(page, bh);
378 block = index << (PAGE_SHIFT - inode->i_blkbits);
379 while (bh) {
380 if (count == 0)
381 bh->b_blocknr = 0;
382 else {
383 bh->b_blocknr = bmap(inode, block);
384 if (bh->b_blocknr == 0) {
385 /* Cannot use this file! */
386 ret = -EINVAL;
387 goto out;
388 }
389 bh->b_bdev = inode->i_sb->s_bdev;
390 if (count < (1<<inode->i_blkbits))
391 count = 0;
392 else
393 count -= (1<<inode->i_blkbits);
394
395 bh->b_end_io = end_bitmap_write;
396 bh->b_private = bitmap;
397 atomic_inc(&bitmap->pending_writes);
398 set_buffer_locked(bh);
399 set_buffer_mapped(bh);
400 submit_bh(REQ_OP_READ, 0, bh);
401 }
402 block++;
403 bh = bh->b_this_page;
404 }
405 page->index = index;
406
407 wait_event(bitmap->write_wait,
408 atomic_read(&bitmap->pending_writes)==0);
409 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
410 ret = -EIO;
411out:
412 if (ret)
413 pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
414 (int)PAGE_SIZE,
415 (unsigned long long)index << PAGE_SHIFT,
416 ret);
417 return ret;
418}
419
420/*
421 * bitmap file superblock operations
422 */
423
424/*
425 * md_bitmap_wait_writes() should be called before writing any bitmap
426 * blocks, to ensure previous writes, particularly from
427 * md_bitmap_daemon_work(), have completed.
428 */
429static void md_bitmap_wait_writes(struct bitmap *bitmap)
430{
431 if (bitmap->storage.file)
432 wait_event(bitmap->write_wait,
433 atomic_read(&bitmap->pending_writes)==0);
434 else
435 /* Note that we ignore the return value. The writes
436 * might have failed, but that would just mean that
437 * some bits which should be cleared haven't been,
438 * which is safe. The relevant bitmap blocks will
439 * probably get written again, but there is no great
440 * loss if they aren't.
441 */
442 md_super_wait(bitmap->mddev);
443}
444
445
446/* update the event counter and sync the superblock to disk */
447void md_bitmap_update_sb(struct bitmap *bitmap)
448{
449 bitmap_super_t *sb;
450
451 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
452 return;
453 if (bitmap->mddev->bitmap_info.external)
454 return;
455 if (!bitmap->storage.sb_page) /* no superblock */
456 return;
457 sb = kmap_atomic(bitmap->storage.sb_page);
458 sb->events = cpu_to_le64(bitmap->mddev->events);
459 if (bitmap->mddev->events < bitmap->events_cleared)
460 /* rocking back to read-only */
461 bitmap->events_cleared = bitmap->mddev->events;
462 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
463 /*
464 * clear BITMAP_WRITE_ERROR bit to protect against the case that
465 * a bitmap write error occurred but the later writes succeeded.
466 */
467 sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR));
468 /* Just in case these have been changed via sysfs: */
469 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
470 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
471 /* This might have been changed by a reshape */
472 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
473 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
474 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
475 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
476 bitmap_info.space);
477 kunmap_atomic(sb);
478 write_page(bitmap, bitmap->storage.sb_page, 1);
479}
480EXPORT_SYMBOL(md_bitmap_update_sb);
481
482/* print out the bitmap file superblock */
483void md_bitmap_print_sb(struct bitmap *bitmap)
484{
485 bitmap_super_t *sb;
486
487 if (!bitmap || !bitmap->storage.sb_page)
488 return;
489 sb = kmap_atomic(bitmap->storage.sb_page);
490 pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
491 pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic));
492 pr_debug(" version: %d\n", le32_to_cpu(sb->version));
493 pr_debug(" uuid: %08x.%08x.%08x.%08x\n",
494 le32_to_cpu(*(__le32 *)(sb->uuid+0)),
495 le32_to_cpu(*(__le32 *)(sb->uuid+4)),
496 le32_to_cpu(*(__le32 *)(sb->uuid+8)),
497 le32_to_cpu(*(__le32 *)(sb->uuid+12)));
498 pr_debug(" events: %llu\n",
499 (unsigned long long) le64_to_cpu(sb->events));
500 pr_debug("events cleared: %llu\n",
501 (unsigned long long) le64_to_cpu(sb->events_cleared));
502 pr_debug(" state: %08x\n", le32_to_cpu(sb->state));
503 pr_debug(" chunksize: %d B\n", le32_to_cpu(sb->chunksize));
504 pr_debug(" daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
505 pr_debug(" sync size: %llu KB\n",
506 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
507 pr_debug("max write behind: %d\n", le32_to_cpu(sb->write_behind));
508 kunmap_atomic(sb);
509}
510
511/*
512 * bitmap_new_disk_sb
513 * @bitmap
514 *
515 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
516 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
517 * This function verifies 'bitmap_info' and populates the on-disk bitmap
518 * structure, which is to be written to disk.
519 *
520 * Returns: 0 on success, -Exxx on error
521 */
522static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
523{
524 bitmap_super_t *sb;
525 unsigned long chunksize, daemon_sleep, write_behind;
526
527 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
528 if (bitmap->storage.sb_page == NULL)
529 return -ENOMEM;
530 bitmap->storage.sb_page->index = 0;
531
532 sb = kmap_atomic(bitmap->storage.sb_page);
533
534 sb->magic = cpu_to_le32(BITMAP_MAGIC);
535 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
536
537 chunksize = bitmap->mddev->bitmap_info.chunksize;
538 BUG_ON(!chunksize);
539 if (!is_power_of_2(chunksize)) {
540 kunmap_atomic(sb);
541 pr_warn("bitmap chunksize not a power of 2\n");
542 return -EINVAL;
543 }
544 sb->chunksize = cpu_to_le32(chunksize);
545
546 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
547 if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
548 pr_debug("Choosing daemon_sleep default (5 sec)\n");
549 daemon_sleep = 5 * HZ;
550 }
551 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
552 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
553
554 /*
555 * FIXME: write_behind for RAID1. If not specified, what
556 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
557 */
558 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
559 if (write_behind > COUNTER_MAX)
560 write_behind = COUNTER_MAX / 2;
561 sb->write_behind = cpu_to_le32(write_behind);
562 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
563
564 /* keep the array size field of the bitmap superblock up to date */
565 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
566
567 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
568
569 set_bit(BITMAP_STALE, &bitmap->flags);
570 sb->state = cpu_to_le32(bitmap->flags);
571 bitmap->events_cleared = bitmap->mddev->events;
572 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
573 bitmap->mddev->bitmap_info.nodes = 0;
574
575 kunmap_atomic(sb);
576
577 return 0;
578}
579
580/* read the superblock from the bitmap file and initialize some bitmap fields */
581static int md_bitmap_read_sb(struct bitmap *bitmap)
582{
583 char *reason = NULL;
584 bitmap_super_t *sb;
585 unsigned long chunksize, daemon_sleep, write_behind;
586 unsigned long long events;
587 int nodes = 0;
588 unsigned long sectors_reserved = 0;
589 int err = -EINVAL;
590 struct page *sb_page;
591 loff_t offset = bitmap->mddev->bitmap_info.offset;
592
593 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
594 chunksize = 128 * 1024 * 1024;
595 daemon_sleep = 5 * HZ;
596 write_behind = 0;
597 set_bit(BITMAP_STALE, &bitmap->flags);
598 err = 0;
599 goto out_no_sb;
600 }
601 /* page 0 is the superblock, read it... */
602 sb_page = alloc_page(GFP_KERNEL);
603 if (!sb_page)
604 return -ENOMEM;
605 bitmap->storage.sb_page = sb_page;
606
607re_read:
608 /* If cluster_slot is set, the cluster is setup */
609 if (bitmap->cluster_slot >= 0) {
610 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
611
612 sector_div(bm_blocks,
613 bitmap->mddev->bitmap_info.chunksize >> 9);
614 /* bits to bytes */
615 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
616 /* to 4k blocks */
617 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
618 offset = bitmap->mddev->bitmap_info.offset + (bitmap->cluster_slot * (bm_blocks << 3));
619 pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
620 bitmap->cluster_slot, offset);
621 }
622
623 if (bitmap->storage.file) {
624 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
625 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
626
627 err = read_page(bitmap->storage.file, 0,
628 bitmap, bytes, sb_page);
629 } else {
630 err = read_sb_page(bitmap->mddev,
631 offset,
632 sb_page,
633 0, sizeof(bitmap_super_t));
634 }
635 if (err)
636 return err;
637
638 err = -EINVAL;
639 sb = kmap_atomic(sb_page);
640
641 chunksize = le32_to_cpu(sb->chunksize);
642 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
643 write_behind = le32_to_cpu(sb->write_behind);
644 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
645 /* Setup nodes/clustername only if bitmap version is
646 * cluster-compatible
647 */
648 if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
649 nodes = le32_to_cpu(sb->nodes);
650 strlcpy(bitmap->mddev->bitmap_info.cluster_name,
651 sb->cluster_name, 64);
652 }
653
654 /* verify that the bitmap-specific fields are valid */
655 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
656 reason = "bad magic";
657 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
658 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
659 reason = "unrecognized superblock version";
660 else if (chunksize < 512)
661 reason = "bitmap chunksize too small";
662 else if (!is_power_of_2(chunksize))
663 reason = "bitmap chunksize not a power of 2";
664 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
665 reason = "daemon sleep period out of range";
666 else if (write_behind > COUNTER_MAX)
667 reason = "write-behind limit out of range (0 - 16383)";
668 if (reason) {
669 pr_warn("%s: invalid bitmap file superblock: %s\n",
670 bmname(bitmap), reason);
671 goto out;
672 }
673
674 /* keep the array size field of the bitmap superblock up to date */
675 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
676
677 if (bitmap->mddev->persistent) {
678 /*
679 * We have a persistent array superblock, so compare the
680 * bitmap's UUID and event counter to the mddev's
681 */
682 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
683 pr_warn("%s: bitmap superblock UUID mismatch\n",
684 bmname(bitmap));
685 goto out;
686 }
687 events = le64_to_cpu(sb->events);
688 if (!nodes && (events < bitmap->mddev->events)) {
689 pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
690 bmname(bitmap), events,
691 (unsigned long long) bitmap->mddev->events);
692 set_bit(BITMAP_STALE, &bitmap->flags);
693 }
694 }
695
696 /* assign fields using values from superblock */
697 bitmap->flags |= le32_to_cpu(sb->state);
698 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
699 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
700 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
701 strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
702 err = 0;
703
704out:
705 kunmap_atomic(sb);
706 /* Assigning chunksize is required for "re_read" */
707 bitmap->mddev->bitmap_info.chunksize = chunksize;
708 if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
709 err = md_setup_cluster(bitmap->mddev, nodes);
710 if (err) {
711 pr_warn("%s: Could not setup cluster service (%d)\n",
712 bmname(bitmap), err);
713 goto out_no_sb;
714 }
715 bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
716 goto re_read;
717 }
718
719
720out_no_sb:
721 if (test_bit(BITMAP_STALE, &bitmap->flags))
722 bitmap->events_cleared = bitmap->mddev->events;
723 bitmap->mddev->bitmap_info.chunksize = chunksize;
724 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
725 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
726 bitmap->mddev->bitmap_info.nodes = nodes;
727 if (bitmap->mddev->bitmap_info.space == 0 ||
728 bitmap->mddev->bitmap_info.space > sectors_reserved)
729 bitmap->mddev->bitmap_info.space = sectors_reserved;
730 if (err) {
731 md_bitmap_print_sb(bitmap);
732 if (bitmap->cluster_slot < 0)
733 md_cluster_stop(bitmap->mddev);
734 }
735 return err;
736}
737
738/*
739 * general bitmap file operations
740 */
741
742/*
743 * on-disk bitmap:
744 *
745 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
746 * file a page at a time. There's a superblock at the start of the file.
747 */
748/* calculate the index of the page that contains this bit */
749static inline unsigned long file_page_index(struct bitmap_storage *store,
750 unsigned long chunk)
751{
752 if (store->sb_page)
753 chunk += sizeof(bitmap_super_t) << 3;
754 return chunk >> PAGE_BIT_SHIFT;
755}
756
757/* calculate the (bit) offset of this bit within a page */
758static inline unsigned long file_page_offset(struct bitmap_storage *store,
759 unsigned long chunk)
760{
761 if (store->sb_page)
762 chunk += sizeof(bitmap_super_t) << 3;
763 return chunk & (PAGE_BITS - 1);
764}
765
766/*
767 * return a pointer to the page in the filemap that contains the given bit
768 *
769 */
770static inline struct page *filemap_get_page(struct bitmap_storage *store,
771 unsigned long chunk)
772{
773 if (file_page_index(store, chunk) >= store->file_pages)
774 return NULL;
775 return store->filemap[file_page_index(store, chunk)];
776}
777
778static int md_bitmap_storage_alloc(struct bitmap_storage *store,
779 unsigned long chunks, int with_super,
780 int slot_number)
781{
782 int pnum, offset = 0;
783 unsigned long num_pages;
784 unsigned long bytes;
785
786 bytes = DIV_ROUND_UP(chunks, 8);
787 if (with_super)
788 bytes += sizeof(bitmap_super_t);
789
790 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
791 offset = slot_number * num_pages;
792
793 store->filemap = kmalloc_array(num_pages, sizeof(struct page *),
794 GFP_KERNEL);
795 if (!store->filemap)
796 return -ENOMEM;
797
798 if (with_super && !store->sb_page) {
799 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
800 if (store->sb_page == NULL)
801 return -ENOMEM;
802 }
803
804 pnum = 0;
805 if (store->sb_page) {
806 store->filemap[0] = store->sb_page;
807 pnum = 1;
808 store->sb_page->index = offset;
809 }
810
811 for ( ; pnum < num_pages; pnum++) {
812 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
813 if (!store->filemap[pnum]) {
814 store->file_pages = pnum;
815 return -ENOMEM;
816 }
817 store->filemap[pnum]->index = pnum + offset;
818 }
819 store->file_pages = pnum;
820
821 /* We need 4 bits per page, rounded up to a multiple
822 * of sizeof(unsigned long) */
823 store->filemap_attr = kzalloc(
824 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
825 GFP_KERNEL);
826 if (!store->filemap_attr)
827 return -ENOMEM;
828
829 store->bytes = bytes;
830
831 return 0;
832}
833
834static void md_bitmap_file_unmap(struct bitmap_storage *store)
835{
836 struct page **map, *sb_page;
837 int pages;
838 struct file *file;
839
840 file = store->file;
841 map = store->filemap;
842 pages = store->file_pages;
843 sb_page = store->sb_page;
844
845 while (pages--)
846 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
847 free_buffers(map[pages]);
848 kfree(map);
849 kfree(store->filemap_attr);
850
851 if (sb_page)
852 free_buffers(sb_page);
853
854 if (file) {
855 struct inode *inode = file_inode(file);
856 invalidate_mapping_pages(inode->i_mapping, 0, -1);
857 fput(file);
858 }
859}
860
861/*
862 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
863 * then it is no longer reliable, so we stop using it and we mark the file
864 * as failed in the superblock
865 */
866static void md_bitmap_file_kick(struct bitmap *bitmap)
867{
868 char *path, *ptr = NULL;
869
870 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
871 md_bitmap_update_sb(bitmap);
872
873 if (bitmap->storage.file) {
874 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
875 if (path)
876 ptr = file_path(bitmap->storage.file,
877 path, PAGE_SIZE);
878
879 pr_warn("%s: kicking failed bitmap file %s from array!\n",
880 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
881
882 kfree(path);
883 } else
884 pr_warn("%s: disabling internal bitmap due to errors\n",
885 bmname(bitmap));
886 }
887}
888
889enum bitmap_page_attr {
890 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
891 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
892 * i.e. counter is 1 or 2. */
893 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
894};
895
896static inline void set_page_attr(struct bitmap *bitmap, int pnum,
897 enum bitmap_page_attr attr)
898{
899 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
900}
901
902static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
903 enum bitmap_page_attr attr)
904{
905 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
906}
907
908static inline int test_page_attr(struct bitmap *bitmap, int pnum,
909 enum bitmap_page_attr attr)
910{
911 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
912}
913
914static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
915 enum bitmap_page_attr attr)
916{
917 return test_and_clear_bit((pnum<<2) + attr,
918 bitmap->storage.filemap_attr);
919}
920/*
921 * bitmap_file_set_bit -- called before performing a write to the md device
922 * to set (and eventually sync) a particular bit in the bitmap file
923 *
924 * we set the bit immediately, then we record the page number so that
925 * when an unplug occurs, we can flush the dirty pages out to disk
926 */
927static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
928{
929 unsigned long bit;
930 struct page *page;
931 void *kaddr;
932 unsigned long chunk = block >> bitmap->counts.chunkshift;
933 struct bitmap_storage *store = &bitmap->storage;
934 unsigned long node_offset = 0;
935
936 if (mddev_is_clustered(bitmap->mddev))
937 node_offset = bitmap->cluster_slot * store->file_pages;
938
939 page = filemap_get_page(&bitmap->storage, chunk);
940 if (!page)
941 return;
942 bit = file_page_offset(&bitmap->storage, chunk);
943
944 /* set the bit */
945 kaddr = kmap_atomic(page);
946 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
947 set_bit(bit, kaddr);
948 else
949 set_bit_le(bit, kaddr);
950 kunmap_atomic(kaddr);
951 pr_debug("set file bit %lu page %lu\n", bit, page->index);
952 /* record page number so it gets flushed to disk when unplug occurs */
953 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_DIRTY);
954}
955
956static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
957{
958 unsigned long bit;
959 struct page *page;
960 void *paddr;
961 unsigned long chunk = block >> bitmap->counts.chunkshift;
962 struct bitmap_storage *store = &bitmap->storage;
963 unsigned long node_offset = 0;
964
965 if (mddev_is_clustered(bitmap->mddev))
966 node_offset = bitmap->cluster_slot * store->file_pages;
967
968 page = filemap_get_page(&bitmap->storage, chunk);
969 if (!page)
970 return;
971 bit = file_page_offset(&bitmap->storage, chunk);
972 paddr = kmap_atomic(page);
973 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
974 clear_bit(bit, paddr);
975 else
976 clear_bit_le(bit, paddr);
977 kunmap_atomic(paddr);
978 if (!test_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
979 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_PENDING);
980 bitmap->allclean = 0;
981 }
982}
983
984static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
985{
986 unsigned long bit;
987 struct page *page;
988 void *paddr;
989 unsigned long chunk = block >> bitmap->counts.chunkshift;
990 int set = 0;
991
992 page = filemap_get_page(&bitmap->storage, chunk);
993 if (!page)
994 return -EINVAL;
995 bit = file_page_offset(&bitmap->storage, chunk);
996 paddr = kmap_atomic(page);
997 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
998 set = test_bit(bit, paddr);
999 else
1000 set = test_bit_le(bit, paddr);
1001 kunmap_atomic(paddr);
1002 return set;
1003}
1004
1005
1006/* this gets called when the md device is ready to unplug its underlying
1007 * (slave) device queues -- before we let any writes go down, we need to
1008 * sync the dirty pages of the bitmap file to disk */
1009void md_bitmap_unplug(struct bitmap *bitmap)
1010{
1011 unsigned long i;
1012 int dirty, need_write;
1013 int writing = 0;
1014
1015 if (!bitmap || !bitmap->storage.filemap ||
1016 test_bit(BITMAP_STALE, &bitmap->flags))
1017 return;
1018
1019 /* look at each page to see if there are any set bits that need to be
1020 * flushed out to disk */
1021 for (i = 0; i < bitmap->storage.file_pages; i++) {
1022 if (!bitmap->storage.filemap)
1023 return;
1024 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1025 need_write = test_and_clear_page_attr(bitmap, i,
1026 BITMAP_PAGE_NEEDWRITE);
1027 if (dirty || need_write) {
1028 if (!writing) {
1029 md_bitmap_wait_writes(bitmap);
1030 if (bitmap->mddev->queue)
1031 blk_add_trace_msg(bitmap->mddev->queue,
1032 "md bitmap_unplug");
1033 }
1034 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
1035 write_page(bitmap, bitmap->storage.filemap[i], 0);
1036 writing = 1;
1037 }
1038 }
1039 if (writing)
1040 md_bitmap_wait_writes(bitmap);
1041
1042 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1043 md_bitmap_file_kick(bitmap);
1044}
1045EXPORT_SYMBOL(md_bitmap_unplug);
1046
1047static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1048/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
1049 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
1050 * memory mapping of the bitmap file
1051 * Special cases:
1052 * if there's no bitmap file, or if the bitmap file had been
1053 * previously kicked from the array, we mark all the bits as
1054 * 1's in order to cause a full resync.
1055 *
1056 * We ignore all bits for sectors that end earlier than 'start'.
1057 * This is used when reading an out-of-date bitmap...
1058 */
1059static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1060{
1061 unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
1062 struct page *page = NULL;
1063 unsigned long bit_cnt = 0;
1064 struct file *file;
1065 unsigned long offset;
1066 int outofdate;
1067 int ret = -ENOSPC;
1068 void *paddr;
1069 struct bitmap_storage *store = &bitmap->storage;
1070
1071 chunks = bitmap->counts.chunks;
1072 file = store->file;
1073
1074 if (!file && !bitmap->mddev->bitmap_info.offset) {
1075 /* No permanent bitmap - fill with '1s'. */
1076 store->filemap = NULL;
1077 store->file_pages = 0;
1078 for (i = 0; i < chunks ; i++) {
1079 /* if the disk bit is set, set the memory bit */
1080 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1081 >= start);
1082 md_bitmap_set_memory_bits(bitmap,
1083 (sector_t)i << bitmap->counts.chunkshift,
1084 needed);
1085 }
1086 return 0;
1087 }
1088
1089 outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1090 if (outofdate)
1091 pr_warn("%s: bitmap file is out of date, doing full recovery\n", bmname(bitmap));
1092
1093 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
1094 pr_warn("%s: bitmap file too short %lu < %lu\n",
1095 bmname(bitmap),
1096 (unsigned long) i_size_read(file->f_mapping->host),
1097 store->bytes);
1098 goto err;
1099 }
1100
1101 oldindex = ~0L;
1102 offset = 0;
1103 if (!bitmap->mddev->bitmap_info.external)
1104 offset = sizeof(bitmap_super_t);
1105
1106 if (mddev_is_clustered(bitmap->mddev))
1107 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1108
1109 for (i = 0; i < chunks; i++) {
1110 int b;
1111 index = file_page_index(&bitmap->storage, i);
1112 bit = file_page_offset(&bitmap->storage, i);
1113 if (index != oldindex) { /* this is a new page, read it in */
1114 int count;
1115 /* unmap the old page, we're done with it */
1116 if (index == store->file_pages-1)
1117 count = store->bytes - index * PAGE_SIZE;
1118 else
1119 count = PAGE_SIZE;
1120 page = store->filemap[index];
1121 if (file)
1122 ret = read_page(file, index, bitmap,
1123 count, page);
1124 else
1125 ret = read_sb_page(
1126 bitmap->mddev,
1127 bitmap->mddev->bitmap_info.offset,
1128 page,
1129 index + node_offset, count);
1130
1131 if (ret)
1132 goto err;
1133
1134 oldindex = index;
1135
1136 if (outofdate) {
1137 /*
1138 * if bitmap is out of date, dirty the
1139 * whole page and write it out
1140 */
1141 paddr = kmap_atomic(page);
1142 memset(paddr + offset, 0xff,
1143 PAGE_SIZE - offset);
1144 kunmap_atomic(paddr);
1145 write_page(bitmap, page, 1);
1146
1147 ret = -EIO;
1148 if (test_bit(BITMAP_WRITE_ERROR,
1149 &bitmap->flags))
1150 goto err;
1151 }
1152 }
1153 paddr = kmap_atomic(page);
1154 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1155 b = test_bit(bit, paddr);
1156 else
1157 b = test_bit_le(bit, paddr);
1158 kunmap_atomic(paddr);
1159 if (b) {
1160 /* if the disk bit is set, set the memory bit */
1161 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1162 >= start);
1163 md_bitmap_set_memory_bits(bitmap,
1164 (sector_t)i << bitmap->counts.chunkshift,
1165 needed);
1166 bit_cnt++;
1167 }
1168 offset = 0;
1169 }
1170
1171 pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
1172 bmname(bitmap), store->file_pages,
1173 bit_cnt, chunks);
1174
1175 return 0;
1176
1177 err:
1178 pr_warn("%s: bitmap initialisation failed: %d\n",
1179 bmname(bitmap), ret);
1180 return ret;
1181}
1182
1183void md_bitmap_write_all(struct bitmap *bitmap)
1184{
1185 /* We don't actually write all bitmap blocks here,
1186 * just flag them as needing to be written
1187 */
1188 int i;
1189
1190 if (!bitmap || !bitmap->storage.filemap)
1191 return;
1192 if (bitmap->storage.file)
1193 /* Only one copy, so nothing needed */
1194 return;
1195
1196 for (i = 0; i < bitmap->storage.file_pages; i++)
1197 set_page_attr(bitmap, i,
1198 BITMAP_PAGE_NEEDWRITE);
1199 bitmap->allclean = 0;
1200}
1201
1202static void md_bitmap_count_page(struct bitmap_counts *bitmap,
1203 sector_t offset, int inc)
1204{
1205 sector_t chunk = offset >> bitmap->chunkshift;
1206 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1207 bitmap->bp[page].count += inc;
1208 md_bitmap_checkfree(bitmap, page);
1209}
1210
1211static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1212{
1213 sector_t chunk = offset >> bitmap->chunkshift;
1214 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1215 struct bitmap_page *bp = &bitmap->bp[page];
1216
1217 if (!bp->pending)
1218 bp->pending = 1;
1219}
1220
1221static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1222 sector_t offset, sector_t *blocks,
1223 int create);
1224
1225/*
1226 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1227 * out to disk
1228 */
1229
1230void md_bitmap_daemon_work(struct mddev *mddev)
1231{
1232 struct bitmap *bitmap;
1233 unsigned long j;
1234 unsigned long nextpage;
1235 sector_t blocks;
1236 struct bitmap_counts *counts;
1237
1238 /* Use a mutex to guard daemon_work against
1239 * bitmap_destroy.
1240 */
1241 mutex_lock(&mddev->bitmap_info.mutex);
1242 bitmap = mddev->bitmap;
1243 if (bitmap == NULL) {
1244 mutex_unlock(&mddev->bitmap_info.mutex);
1245 return;
1246 }
1247 if (time_before(jiffies, bitmap->daemon_lastrun
1248 + mddev->bitmap_info.daemon_sleep))
1249 goto done;
1250
1251 bitmap->daemon_lastrun = jiffies;
1252 if (bitmap->allclean) {
1253 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1254 goto done;
1255 }
1256 bitmap->allclean = 1;
1257
1258 if (bitmap->mddev->queue)
1259 blk_add_trace_msg(bitmap->mddev->queue,
1260 "md bitmap_daemon_work");
1261
1262 /* Any file-page which is PENDING now needs to be written.
1263 * So set NEEDWRITE now, then after we make any last-minute changes
1264 * we will write it.
1265 */
1266 for (j = 0; j < bitmap->storage.file_pages; j++)
1267 if (test_and_clear_page_attr(bitmap, j,
1268 BITMAP_PAGE_PENDING))
1269 set_page_attr(bitmap, j,
1270 BITMAP_PAGE_NEEDWRITE);
1271
1272 if (bitmap->need_sync &&
1273 mddev->bitmap_info.external == 0) {
1274 /* Arrange for superblock update as well as
1275 * other changes */
1276 bitmap_super_t *sb;
1277 bitmap->need_sync = 0;
1278 if (bitmap->storage.filemap) {
1279 sb = kmap_atomic(bitmap->storage.sb_page);
1280 sb->events_cleared =
1281 cpu_to_le64(bitmap->events_cleared);
1282 kunmap_atomic(sb);
1283 set_page_attr(bitmap, 0,
1284 BITMAP_PAGE_NEEDWRITE);
1285 }
1286 }
1287 /* Now look at the bitmap counters and if any are '2' or '1',
1288 * decrement and handle accordingly.
1289 */
1290 counts = &bitmap->counts;
1291 spin_lock_irq(&counts->lock);
1292 nextpage = 0;
1293 for (j = 0; j < counts->chunks; j++) {
1294 bitmap_counter_t *bmc;
1295 sector_t block = (sector_t)j << counts->chunkshift;
1296
1297 if (j == nextpage) {
1298 nextpage += PAGE_COUNTER_RATIO;
1299 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1300 j |= PAGE_COUNTER_MASK;
1301 continue;
1302 }
1303 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1304 }
1305
1306 bmc = md_bitmap_get_counter(counts, block, &blocks, 0);
1307 if (!bmc) {
1308 j |= PAGE_COUNTER_MASK;
1309 continue;
1310 }
1311 if (*bmc == 1 && !bitmap->need_sync) {
1312 /* We can clear the bit */
1313 *bmc = 0;
1314 md_bitmap_count_page(counts, block, -1);
1315 md_bitmap_file_clear_bit(bitmap, block);
1316 } else if (*bmc && *bmc <= 2) {
1317 *bmc = 1;
1318 md_bitmap_set_pending(counts, block);
1319 bitmap->allclean = 0;
1320 }
1321 }
1322 spin_unlock_irq(&counts->lock);
1323
1324 md_bitmap_wait_writes(bitmap);
1325 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1326 * DIRTY pages need to be written by bitmap_unplug so it can wait
1327 * for them.
1328 * If we find any DIRTY page we stop there and let bitmap_unplug
1329 * handle all the rest. This is important in the case where
1330 * the first blocking holds the superblock and it has been updated.
1331 * We mustn't write any other blocks before the superblock.
1332 */
1333 for (j = 0;
1334 j < bitmap->storage.file_pages
1335 && !test_bit(BITMAP_STALE, &bitmap->flags);
1336 j++) {
1337 if (test_page_attr(bitmap, j,
1338 BITMAP_PAGE_DIRTY))
1339 /* bitmap_unplug will handle the rest */
1340 break;
1341 if (test_and_clear_page_attr(bitmap, j,
1342 BITMAP_PAGE_NEEDWRITE)) {
1343 write_page(bitmap, bitmap->storage.filemap[j], 0);
1344 }
1345 }
1346
1347 done:
1348 if (bitmap->allclean == 0)
1349 mddev->thread->timeout =
1350 mddev->bitmap_info.daemon_sleep;
1351 mutex_unlock(&mddev->bitmap_info.mutex);
1352}
1353
1354static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1355 sector_t offset, sector_t *blocks,
1356 int create)
1357__releases(bitmap->lock)
1358__acquires(bitmap->lock)
1359{
1360 /* If 'create', we might release the lock and reclaim it.
1361 * The lock must have been taken with interrupts enabled.
1362 * If !create, we don't release the lock.
1363 */
1364 sector_t chunk = offset >> bitmap->chunkshift;
1365 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1366 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1367 sector_t csize;
1368 int err;
1369
1370 err = md_bitmap_checkpage(bitmap, page, create, 0);
1371
1372 if (bitmap->bp[page].hijacked ||
1373 bitmap->bp[page].map == NULL)
1374 csize = ((sector_t)1) << (bitmap->chunkshift +
1375 PAGE_COUNTER_SHIFT - 1);
1376 else
1377 csize = ((sector_t)1) << bitmap->chunkshift;
1378 *blocks = csize - (offset & (csize - 1));
1379
1380 if (err < 0)
1381 return NULL;
1382
1383 /* now locked ... */
1384
1385 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1386 /* should we use the first or second counter field
1387 * of the hijacked pointer? */
1388 int hi = (pageoff > PAGE_COUNTER_MASK);
1389 return &((bitmap_counter_t *)
1390 &bitmap->bp[page].map)[hi];
1391 } else /* page is allocated */
1392 return (bitmap_counter_t *)
1393 &(bitmap->bp[page].map[pageoff]);
1394}
1395
1396int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1397{
1398 if (!bitmap)
1399 return 0;
1400
1401 if (behind) {
1402 int bw;
1403 atomic_inc(&bitmap->behind_writes);
1404 bw = atomic_read(&bitmap->behind_writes);
1405 if (bw > bitmap->behind_writes_used)
1406 bitmap->behind_writes_used = bw;
1407
1408 pr_debug("inc write-behind count %d/%lu\n",
1409 bw, bitmap->mddev->bitmap_info.max_write_behind);
1410 }
1411
1412 while (sectors) {
1413 sector_t blocks;
1414 bitmap_counter_t *bmc;
1415
1416 spin_lock_irq(&bitmap->counts.lock);
1417 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1418 if (!bmc) {
1419 spin_unlock_irq(&bitmap->counts.lock);
1420 return 0;
1421 }
1422
1423 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1424 DEFINE_WAIT(__wait);
1425 /* note that it is safe to do the prepare_to_wait
1426 * after the test as long as we do it before dropping
1427 * the spinlock.
1428 */
1429 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1430 TASK_UNINTERRUPTIBLE);
1431 spin_unlock_irq(&bitmap->counts.lock);
1432 schedule();
1433 finish_wait(&bitmap->overflow_wait, &__wait);
1434 continue;
1435 }
1436
1437 switch (*bmc) {
1438 case 0:
1439 md_bitmap_file_set_bit(bitmap, offset);
1440 md_bitmap_count_page(&bitmap->counts, offset, 1);
1441 /* fall through */
1442 case 1:
1443 *bmc = 2;
1444 }
1445
1446 (*bmc)++;
1447
1448 spin_unlock_irq(&bitmap->counts.lock);
1449
1450 offset += blocks;
1451 if (sectors > blocks)
1452 sectors -= blocks;
1453 else
1454 sectors = 0;
1455 }
1456 return 0;
1457}
1458EXPORT_SYMBOL(md_bitmap_startwrite);
1459
1460void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
1461 unsigned long sectors, int success, int behind)
1462{
1463 if (!bitmap)
1464 return;
1465 if (behind) {
1466 if (atomic_dec_and_test(&bitmap->behind_writes))
1467 wake_up(&bitmap->behind_wait);
1468 pr_debug("dec write-behind count %d/%lu\n",
1469 atomic_read(&bitmap->behind_writes),
1470 bitmap->mddev->bitmap_info.max_write_behind);
1471 }
1472
1473 while (sectors) {
1474 sector_t blocks;
1475 unsigned long flags;
1476 bitmap_counter_t *bmc;
1477
1478 spin_lock_irqsave(&bitmap->counts.lock, flags);
1479 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1480 if (!bmc) {
1481 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1482 return;
1483 }
1484
1485 if (success && !bitmap->mddev->degraded &&
1486 bitmap->events_cleared < bitmap->mddev->events) {
1487 bitmap->events_cleared = bitmap->mddev->events;
1488 bitmap->need_sync = 1;
1489 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1490 }
1491
1492 if (!success && !NEEDED(*bmc))
1493 *bmc |= NEEDED_MASK;
1494
1495 if (COUNTER(*bmc) == COUNTER_MAX)
1496 wake_up(&bitmap->overflow_wait);
1497
1498 (*bmc)--;
1499 if (*bmc <= 2) {
1500 md_bitmap_set_pending(&bitmap->counts, offset);
1501 bitmap->allclean = 0;
1502 }
1503 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1504 offset += blocks;
1505 if (sectors > blocks)
1506 sectors -= blocks;
1507 else
1508 sectors = 0;
1509 }
1510}
1511EXPORT_SYMBOL(md_bitmap_endwrite);
1512
1513static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1514 int degraded)
1515{
1516 bitmap_counter_t *bmc;
1517 int rv;
1518 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1519 *blocks = 1024;
1520 return 1; /* always resync if no bitmap */
1521 }
1522 spin_lock_irq(&bitmap->counts.lock);
1523 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1524 rv = 0;
1525 if (bmc) {
1526 /* locked */
1527 if (RESYNC(*bmc))
1528 rv = 1;
1529 else if (NEEDED(*bmc)) {
1530 rv = 1;
1531 if (!degraded) { /* don't set/clear bits if degraded */
1532 *bmc |= RESYNC_MASK;
1533 *bmc &= ~NEEDED_MASK;
1534 }
1535 }
1536 }
1537 spin_unlock_irq(&bitmap->counts.lock);
1538 return rv;
1539}
1540
1541int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1542 int degraded)
1543{
1544 /* bitmap_start_sync must always report on multiples of whole
1545 * pages, otherwise resync (which is very PAGE_SIZE based) will
1546 * get confused.
1547 * So call __bitmap_start_sync repeatedly (if needed) until
1548 * At least PAGE_SIZE>>9 blocks are covered.
1549 * Return the 'or' of the result.
1550 */
1551 int rv = 0;
1552 sector_t blocks1;
1553
1554 *blocks = 0;
1555 while (*blocks < (PAGE_SIZE>>9)) {
1556 rv |= __bitmap_start_sync(bitmap, offset,
1557 &blocks1, degraded);
1558 offset += blocks1;
1559 *blocks += blocks1;
1560 }
1561 return rv;
1562}
1563EXPORT_SYMBOL(md_bitmap_start_sync);
1564
1565void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1566{
1567 bitmap_counter_t *bmc;
1568 unsigned long flags;
1569
1570 if (bitmap == NULL) {
1571 *blocks = 1024;
1572 return;
1573 }
1574 spin_lock_irqsave(&bitmap->counts.lock, flags);
1575 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1576 if (bmc == NULL)
1577 goto unlock;
1578 /* locked */
1579 if (RESYNC(*bmc)) {
1580 *bmc &= ~RESYNC_MASK;
1581
1582 if (!NEEDED(*bmc) && aborted)
1583 *bmc |= NEEDED_MASK;
1584 else {
1585 if (*bmc <= 2) {
1586 md_bitmap_set_pending(&bitmap->counts, offset);
1587 bitmap->allclean = 0;
1588 }
1589 }
1590 }
1591 unlock:
1592 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1593}
1594EXPORT_SYMBOL(md_bitmap_end_sync);
1595
1596void md_bitmap_close_sync(struct bitmap *bitmap)
1597{
1598 /* Sync has finished, and any bitmap chunks that weren't synced
1599 * properly have been aborted. It remains to us to clear the
1600 * RESYNC bit wherever it is still on
1601 */
1602 sector_t sector = 0;
1603 sector_t blocks;
1604 if (!bitmap)
1605 return;
1606 while (sector < bitmap->mddev->resync_max_sectors) {
1607 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1608 sector += blocks;
1609 }
1610}
1611EXPORT_SYMBOL(md_bitmap_close_sync);
1612
1613void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
1614{
1615 sector_t s = 0;
1616 sector_t blocks;
1617
1618 if (!bitmap)
1619 return;
1620 if (sector == 0) {
1621 bitmap->last_end_sync = jiffies;
1622 return;
1623 }
1624 if (!force && time_before(jiffies, (bitmap->last_end_sync
1625 + bitmap->mddev->bitmap_info.daemon_sleep)))
1626 return;
1627 wait_event(bitmap->mddev->recovery_wait,
1628 atomic_read(&bitmap->mddev->recovery_active) == 0);
1629
1630 bitmap->mddev->curr_resync_completed = sector;
1631 set_bit(MD_SB_CHANGE_CLEAN, &bitmap->mddev->sb_flags);
1632 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1633 s = 0;
1634 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1635 md_bitmap_end_sync(bitmap, s, &blocks, 0);
1636 s += blocks;
1637 }
1638 bitmap->last_end_sync = jiffies;
1639 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1640}
1641EXPORT_SYMBOL(md_bitmap_cond_end_sync);
1642
1643void md_bitmap_sync_with_cluster(struct mddev *mddev,
1644 sector_t old_lo, sector_t old_hi,
1645 sector_t new_lo, sector_t new_hi)
1646{
1647 struct bitmap *bitmap = mddev->bitmap;
1648 sector_t sector, blocks = 0;
1649
1650 for (sector = old_lo; sector < new_lo; ) {
1651 md_bitmap_end_sync(bitmap, sector, &blocks, 0);
1652 sector += blocks;
1653 }
1654 WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
1655
1656 for (sector = old_hi; sector < new_hi; ) {
1657 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1658 sector += blocks;
1659 }
1660 WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
1661}
1662EXPORT_SYMBOL(md_bitmap_sync_with_cluster);
1663
1664static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1665{
1666 /* For each chunk covered by any of these sectors, set the
1667 * counter to 2 and possibly set resync_needed. They should all
1668 * be 0 at this point
1669 */
1670
1671 sector_t secs;
1672 bitmap_counter_t *bmc;
1673 spin_lock_irq(&bitmap->counts.lock);
1674 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1675 if (!bmc) {
1676 spin_unlock_irq(&bitmap->counts.lock);
1677 return;
1678 }
1679 if (!*bmc) {
1680 *bmc = 2;
1681 md_bitmap_count_page(&bitmap->counts, offset, 1);
1682 md_bitmap_set_pending(&bitmap->counts, offset);
1683 bitmap->allclean = 0;
1684 }
1685 if (needed)
1686 *bmc |= NEEDED_MASK;
1687 spin_unlock_irq(&bitmap->counts.lock);
1688}
1689
1690/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1691void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1692{
1693 unsigned long chunk;
1694
1695 for (chunk = s; chunk <= e; chunk++) {
1696 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1697 md_bitmap_set_memory_bits(bitmap, sec, 1);
1698 md_bitmap_file_set_bit(bitmap, sec);
1699 if (sec < bitmap->mddev->recovery_cp)
1700 /* We are asserting that the array is dirty,
1701 * so move the recovery_cp address back so
1702 * that it is obvious that it is dirty
1703 */
1704 bitmap->mddev->recovery_cp = sec;
1705 }
1706}
1707
1708/*
1709 * flush out any pending updates
1710 */
1711void md_bitmap_flush(struct mddev *mddev)
1712{
1713 struct bitmap *bitmap = mddev->bitmap;
1714 long sleep;
1715
1716 if (!bitmap) /* there was no bitmap */
1717 return;
1718
1719 /* run the daemon_work three time to ensure everything is flushed
1720 * that can be
1721 */
1722 sleep = mddev->bitmap_info.daemon_sleep * 2;
1723 bitmap->daemon_lastrun -= sleep;
1724 md_bitmap_daemon_work(mddev);
1725 bitmap->daemon_lastrun -= sleep;
1726 md_bitmap_daemon_work(mddev);
1727 bitmap->daemon_lastrun -= sleep;
1728 md_bitmap_daemon_work(mddev);
1729 md_bitmap_update_sb(bitmap);
1730}
1731
1732/*
1733 * free memory that was allocated
1734 */
1735void md_bitmap_free(struct bitmap *bitmap)
1736{
1737 unsigned long k, pages;
1738 struct bitmap_page *bp;
1739
1740 if (!bitmap) /* there was no bitmap */
1741 return;
1742
1743 if (bitmap->sysfs_can_clear)
1744 sysfs_put(bitmap->sysfs_can_clear);
1745
1746 if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
1747 bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
1748 md_cluster_stop(bitmap->mddev);
1749
1750 /* Shouldn't be needed - but just in case.... */
1751 wait_event(bitmap->write_wait,
1752 atomic_read(&bitmap->pending_writes) == 0);
1753
1754 /* release the bitmap file */
1755 md_bitmap_file_unmap(&bitmap->storage);
1756
1757 bp = bitmap->counts.bp;
1758 pages = bitmap->counts.pages;
1759
1760 /* free all allocated memory */
1761
1762 if (bp) /* deallocate the page memory */
1763 for (k = 0; k < pages; k++)
1764 if (bp[k].map && !bp[k].hijacked)
1765 kfree(bp[k].map);
1766 kfree(bp);
1767 kfree(bitmap);
1768}
1769EXPORT_SYMBOL(md_bitmap_free);
1770
1771void md_bitmap_wait_behind_writes(struct mddev *mddev)
1772{
1773 struct bitmap *bitmap = mddev->bitmap;
1774
1775 /* wait for behind writes to complete */
1776 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1777 pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
1778 mdname(mddev));
1779 /* need to kick something here to make sure I/O goes? */
1780 wait_event(bitmap->behind_wait,
1781 atomic_read(&bitmap->behind_writes) == 0);
1782 }
1783}
1784
1785void md_bitmap_destroy(struct mddev *mddev)
1786{
1787 struct bitmap *bitmap = mddev->bitmap;
1788
1789 if (!bitmap) /* there was no bitmap */
1790 return;
1791
1792 md_bitmap_wait_behind_writes(mddev);
1793 mempool_destroy(mddev->wb_info_pool);
1794 mddev->wb_info_pool = NULL;
1795
1796 mutex_lock(&mddev->bitmap_info.mutex);
1797 spin_lock(&mddev->lock);
1798 mddev->bitmap = NULL; /* disconnect from the md device */
1799 spin_unlock(&mddev->lock);
1800 mutex_unlock(&mddev->bitmap_info.mutex);
1801 if (mddev->thread)
1802 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1803
1804 md_bitmap_free(bitmap);
1805}
1806
1807/*
1808 * initialize the bitmap structure
1809 * if this returns an error, bitmap_destroy must be called to do clean up
1810 * once mddev->bitmap is set
1811 */
1812struct bitmap *md_bitmap_create(struct mddev *mddev, int slot)
1813{
1814 struct bitmap *bitmap;
1815 sector_t blocks = mddev->resync_max_sectors;
1816 struct file *file = mddev->bitmap_info.file;
1817 int err;
1818 struct kernfs_node *bm = NULL;
1819
1820 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1821
1822 BUG_ON(file && mddev->bitmap_info.offset);
1823
1824 if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
1825 pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
1826 mdname(mddev));
1827 return ERR_PTR(-EBUSY);
1828 }
1829
1830 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1831 if (!bitmap)
1832 return ERR_PTR(-ENOMEM);
1833
1834 spin_lock_init(&bitmap->counts.lock);
1835 atomic_set(&bitmap->pending_writes, 0);
1836 init_waitqueue_head(&bitmap->write_wait);
1837 init_waitqueue_head(&bitmap->overflow_wait);
1838 init_waitqueue_head(&bitmap->behind_wait);
1839
1840 bitmap->mddev = mddev;
1841 bitmap->cluster_slot = slot;
1842
1843 if (mddev->kobj.sd)
1844 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
1845 if (bm) {
1846 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
1847 sysfs_put(bm);
1848 } else
1849 bitmap->sysfs_can_clear = NULL;
1850
1851 bitmap->storage.file = file;
1852 if (file) {
1853 get_file(file);
1854 /* As future accesses to this file will use bmap,
1855 * and bypass the page cache, we must sync the file
1856 * first.
1857 */
1858 vfs_fsync(file, 1);
1859 }
1860 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1861 if (!mddev->bitmap_info.external) {
1862 /*
1863 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1864 * instructing us to create a new on-disk bitmap instance.
1865 */
1866 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1867 err = md_bitmap_new_disk_sb(bitmap);
1868 else
1869 err = md_bitmap_read_sb(bitmap);
1870 } else {
1871 err = 0;
1872 if (mddev->bitmap_info.chunksize == 0 ||
1873 mddev->bitmap_info.daemon_sleep == 0)
1874 /* chunksize and time_base need to be
1875 * set first. */
1876 err = -EINVAL;
1877 }
1878 if (err)
1879 goto error;
1880
1881 bitmap->daemon_lastrun = jiffies;
1882 err = md_bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1883 if (err)
1884 goto error;
1885
1886 pr_debug("created bitmap (%lu pages) for device %s\n",
1887 bitmap->counts.pages, bmname(bitmap));
1888
1889 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1890 if (err)
1891 goto error;
1892
1893 return bitmap;
1894 error:
1895 md_bitmap_free(bitmap);
1896 return ERR_PTR(err);
1897}
1898
1899int md_bitmap_load(struct mddev *mddev)
1900{
1901 int err = 0;
1902 sector_t start = 0;
1903 sector_t sector = 0;
1904 struct bitmap *bitmap = mddev->bitmap;
1905 struct md_rdev *rdev;
1906
1907 if (!bitmap)
1908 goto out;
1909
1910 rdev_for_each(rdev, mddev)
1911 mddev_create_wb_pool(mddev, rdev, true);
1912
1913 if (mddev_is_clustered(mddev))
1914 md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
1915
1916 /* Clear out old bitmap info first: Either there is none, or we
1917 * are resuming after someone else has possibly changed things,
1918 * so we should forget old cached info.
1919 * All chunks should be clean, but some might need_sync.
1920 */
1921 while (sector < mddev->resync_max_sectors) {
1922 sector_t blocks;
1923 md_bitmap_start_sync(bitmap, sector, &blocks, 0);
1924 sector += blocks;
1925 }
1926 md_bitmap_close_sync(bitmap);
1927
1928 if (mddev->degraded == 0
1929 || bitmap->events_cleared == mddev->events)
1930 /* no need to keep dirty bits to optimise a
1931 * re-add of a missing device */
1932 start = mddev->recovery_cp;
1933
1934 mutex_lock(&mddev->bitmap_info.mutex);
1935 err = md_bitmap_init_from_disk(bitmap, start);
1936 mutex_unlock(&mddev->bitmap_info.mutex);
1937
1938 if (err)
1939 goto out;
1940 clear_bit(BITMAP_STALE, &bitmap->flags);
1941
1942 /* Kick recovery in case any bits were set */
1943 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1944
1945 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1946 md_wakeup_thread(mddev->thread);
1947
1948 md_bitmap_update_sb(bitmap);
1949
1950 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1951 err = -EIO;
1952out:
1953 return err;
1954}
1955EXPORT_SYMBOL_GPL(md_bitmap_load);
1956
1957struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
1958{
1959 int rv = 0;
1960 struct bitmap *bitmap;
1961
1962 bitmap = md_bitmap_create(mddev, slot);
1963 if (IS_ERR(bitmap)) {
1964 rv = PTR_ERR(bitmap);
1965 return ERR_PTR(rv);
1966 }
1967
1968 rv = md_bitmap_init_from_disk(bitmap, 0);
1969 if (rv) {
1970 md_bitmap_free(bitmap);
1971 return ERR_PTR(rv);
1972 }
1973
1974 return bitmap;
1975}
1976EXPORT_SYMBOL(get_bitmap_from_slot);
1977
1978/* Loads the bitmap associated with slot and copies the resync information
1979 * to our bitmap
1980 */
1981int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
1982 sector_t *low, sector_t *high, bool clear_bits)
1983{
1984 int rv = 0, i, j;
1985 sector_t block, lo = 0, hi = 0;
1986 struct bitmap_counts *counts;
1987 struct bitmap *bitmap;
1988
1989 bitmap = get_bitmap_from_slot(mddev, slot);
1990 if (IS_ERR(bitmap)) {
1991 pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
1992 return -1;
1993 }
1994
1995 counts = &bitmap->counts;
1996 for (j = 0; j < counts->chunks; j++) {
1997 block = (sector_t)j << counts->chunkshift;
1998 if (md_bitmap_file_test_bit(bitmap, block)) {
1999 if (!lo)
2000 lo = block;
2001 hi = block;
2002 md_bitmap_file_clear_bit(bitmap, block);
2003 md_bitmap_set_memory_bits(mddev->bitmap, block, 1);
2004 md_bitmap_file_set_bit(mddev->bitmap, block);
2005 }
2006 }
2007
2008 if (clear_bits) {
2009 md_bitmap_update_sb(bitmap);
2010 /* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
2011 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
2012 for (i = 0; i < bitmap->storage.file_pages; i++)
2013 if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
2014 set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
2015 md_bitmap_unplug(bitmap);
2016 }
2017 md_bitmap_unplug(mddev->bitmap);
2018 *low = lo;
2019 *high = hi;
2020
2021 return rv;
2022}
2023EXPORT_SYMBOL_GPL(md_bitmap_copy_from_slot);
2024
2025
2026void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
2027{
2028 unsigned long chunk_kb;
2029 struct bitmap_counts *counts;
2030
2031 if (!bitmap)
2032 return;
2033
2034 counts = &bitmap->counts;
2035
2036 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
2037 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
2038 "%lu%s chunk",
2039 counts->pages - counts->missing_pages,
2040 counts->pages,
2041 (counts->pages - counts->missing_pages)
2042 << (PAGE_SHIFT - 10),
2043 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
2044 chunk_kb ? "KB" : "B");
2045 if (bitmap->storage.file) {
2046 seq_printf(seq, ", file: ");
2047 seq_file_path(seq, bitmap->storage.file, " \t\n");
2048 }
2049
2050 seq_printf(seq, "\n");
2051}
2052
2053int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
2054 int chunksize, int init)
2055{
2056 /* If chunk_size is 0, choose an appropriate chunk size.
2057 * Then possibly allocate new storage space.
2058 * Then quiesce, copy bits, replace bitmap, and re-start
2059 *
2060 * This function is called both to set up the initial bitmap
2061 * and to resize the bitmap while the array is active.
2062 * If this happens as a result of the array being resized,
2063 * chunksize will be zero, and we need to choose a suitable
2064 * chunksize, otherwise we use what we are given.
2065 */
2066 struct bitmap_storage store;
2067 struct bitmap_counts old_counts;
2068 unsigned long chunks;
2069 sector_t block;
2070 sector_t old_blocks, new_blocks;
2071 int chunkshift;
2072 int ret = 0;
2073 long pages;
2074 struct bitmap_page *new_bp;
2075
2076 if (bitmap->storage.file && !init) {
2077 pr_info("md: cannot resize file-based bitmap\n");
2078 return -EINVAL;
2079 }
2080
2081 if (chunksize == 0) {
2082 /* If there is enough space, leave the chunk size unchanged,
2083 * else increase by factor of two until there is enough space.
2084 */
2085 long bytes;
2086 long space = bitmap->mddev->bitmap_info.space;
2087
2088 if (space == 0) {
2089 /* We don't know how much space there is, so limit
2090 * to current size - in sectors.
2091 */
2092 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
2093 if (!bitmap->mddev->bitmap_info.external)
2094 bytes += sizeof(bitmap_super_t);
2095 space = DIV_ROUND_UP(bytes, 512);
2096 bitmap->mddev->bitmap_info.space = space;
2097 }
2098 chunkshift = bitmap->counts.chunkshift;
2099 chunkshift--;
2100 do {
2101 /* 'chunkshift' is shift from block size to chunk size */
2102 chunkshift++;
2103 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2104 bytes = DIV_ROUND_UP(chunks, 8);
2105 if (!bitmap->mddev->bitmap_info.external)
2106 bytes += sizeof(bitmap_super_t);
2107 } while (bytes > (space << 9));
2108 } else
2109 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
2110
2111 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2112 memset(&store, 0, sizeof(store));
2113 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2114 ret = md_bitmap_storage_alloc(&store, chunks,
2115 !bitmap->mddev->bitmap_info.external,
2116 mddev_is_clustered(bitmap->mddev)
2117 ? bitmap->cluster_slot : 0);
2118 if (ret) {
2119 md_bitmap_file_unmap(&store);
2120 goto err;
2121 }
2122
2123 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2124
2125 new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
2126 ret = -ENOMEM;
2127 if (!new_bp) {
2128 md_bitmap_file_unmap(&store);
2129 goto err;
2130 }
2131
2132 if (!init)
2133 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2134
2135 store.file = bitmap->storage.file;
2136 bitmap->storage.file = NULL;
2137
2138 if (store.sb_page && bitmap->storage.sb_page)
2139 memcpy(page_address(store.sb_page),
2140 page_address(bitmap->storage.sb_page),
2141 sizeof(bitmap_super_t));
2142 md_bitmap_file_unmap(&bitmap->storage);
2143 bitmap->storage = store;
2144
2145 old_counts = bitmap->counts;
2146 bitmap->counts.bp = new_bp;
2147 bitmap->counts.pages = pages;
2148 bitmap->counts.missing_pages = pages;
2149 bitmap->counts.chunkshift = chunkshift;
2150 bitmap->counts.chunks = chunks;
2151 bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift +
2152 BITMAP_BLOCK_SHIFT);
2153
2154 blocks = min(old_counts.chunks << old_counts.chunkshift,
2155 chunks << chunkshift);
2156
2157 spin_lock_irq(&bitmap->counts.lock);
2158 /* For cluster raid, need to pre-allocate bitmap */
2159 if (mddev_is_clustered(bitmap->mddev)) {
2160 unsigned long page;
2161 for (page = 0; page < pages; page++) {
2162 ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1);
2163 if (ret) {
2164 unsigned long k;
2165
2166 /* deallocate the page memory */
2167 for (k = 0; k < page; k++) {
2168 kfree(new_bp[k].map);
2169 }
2170 kfree(new_bp);
2171
2172 /* restore some fields from old_counts */
2173 bitmap->counts.bp = old_counts.bp;
2174 bitmap->counts.pages = old_counts.pages;
2175 bitmap->counts.missing_pages = old_counts.pages;
2176 bitmap->counts.chunkshift = old_counts.chunkshift;
2177 bitmap->counts.chunks = old_counts.chunks;
2178 bitmap->mddev->bitmap_info.chunksize = 1 << (old_counts.chunkshift +
2179 BITMAP_BLOCK_SHIFT);
2180 blocks = old_counts.chunks << old_counts.chunkshift;
2181 pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
2182 break;
2183 } else
2184 bitmap->counts.bp[page].count += 1;
2185 }
2186 }
2187
2188 for (block = 0; block < blocks; ) {
2189 bitmap_counter_t *bmc_old, *bmc_new;
2190 int set;
2191
2192 bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0);
2193 set = bmc_old && NEEDED(*bmc_old);
2194
2195 if (set) {
2196 bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2197 if (*bmc_new == 0) {
2198 /* need to set on-disk bits too. */
2199 sector_t end = block + new_blocks;
2200 sector_t start = block >> chunkshift;
2201 start <<= chunkshift;
2202 while (start < end) {
2203 md_bitmap_file_set_bit(bitmap, block);
2204 start += 1 << chunkshift;
2205 }
2206 *bmc_new = 2;
2207 md_bitmap_count_page(&bitmap->counts, block, 1);
2208 md_bitmap_set_pending(&bitmap->counts, block);
2209 }
2210 *bmc_new |= NEEDED_MASK;
2211 if (new_blocks < old_blocks)
2212 old_blocks = new_blocks;
2213 }
2214 block += old_blocks;
2215 }
2216
2217 if (bitmap->counts.bp != old_counts.bp) {
2218 unsigned long k;
2219 for (k = 0; k < old_counts.pages; k++)
2220 if (!old_counts.bp[k].hijacked)
2221 kfree(old_counts.bp[k].map);
2222 kfree(old_counts.bp);
2223 }
2224
2225 if (!init) {
2226 int i;
2227 while (block < (chunks << chunkshift)) {
2228 bitmap_counter_t *bmc;
2229 bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2230 if (bmc) {
2231 /* new space. It needs to be resynced, so
2232 * we set NEEDED_MASK.
2233 */
2234 if (*bmc == 0) {
2235 *bmc = NEEDED_MASK | 2;
2236 md_bitmap_count_page(&bitmap->counts, block, 1);
2237 md_bitmap_set_pending(&bitmap->counts, block);
2238 }
2239 }
2240 block += new_blocks;
2241 }
2242 for (i = 0; i < bitmap->storage.file_pages; i++)
2243 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
2244 }
2245 spin_unlock_irq(&bitmap->counts.lock);
2246
2247 if (!init) {
2248 md_bitmap_unplug(bitmap);
2249 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2250 }
2251 ret = 0;
2252err:
2253 return ret;
2254}
2255EXPORT_SYMBOL_GPL(md_bitmap_resize);
2256
2257static ssize_t
2258location_show(struct mddev *mddev, char *page)
2259{
2260 ssize_t len;
2261 if (mddev->bitmap_info.file)
2262 len = sprintf(page, "file");
2263 else if (mddev->bitmap_info.offset)
2264 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
2265 else
2266 len = sprintf(page, "none");
2267 len += sprintf(page+len, "\n");
2268 return len;
2269}
2270
2271static ssize_t
2272location_store(struct mddev *mddev, const char *buf, size_t len)
2273{
2274 int rv;
2275
2276 rv = mddev_lock(mddev);
2277 if (rv)
2278 return rv;
2279 if (mddev->pers) {
2280 if (!mddev->pers->quiesce) {
2281 rv = -EBUSY;
2282 goto out;
2283 }
2284 if (mddev->recovery || mddev->sync_thread) {
2285 rv = -EBUSY;
2286 goto out;
2287 }
2288 }
2289
2290 if (mddev->bitmap || mddev->bitmap_info.file ||
2291 mddev->bitmap_info.offset) {
2292 /* bitmap already configured. Only option is to clear it */
2293 if (strncmp(buf, "none", 4) != 0) {
2294 rv = -EBUSY;
2295 goto out;
2296 }
2297 if (mddev->pers) {
2298 mddev_suspend(mddev);
2299 md_bitmap_destroy(mddev);
2300 mddev_resume(mddev);
2301 }
2302 mddev->bitmap_info.offset = 0;
2303 if (mddev->bitmap_info.file) {
2304 struct file *f = mddev->bitmap_info.file;
2305 mddev->bitmap_info.file = NULL;
2306 fput(f);
2307 }
2308 } else {
2309 /* No bitmap, OK to set a location */
2310 long long offset;
2311 if (strncmp(buf, "none", 4) == 0)
2312 /* nothing to be done */;
2313 else if (strncmp(buf, "file:", 5) == 0) {
2314 /* Not supported yet */
2315 rv = -EINVAL;
2316 goto out;
2317 } else {
2318 if (buf[0] == '+')
2319 rv = kstrtoll(buf+1, 10, &offset);
2320 else
2321 rv = kstrtoll(buf, 10, &offset);
2322 if (rv)
2323 goto out;
2324 if (offset == 0) {
2325 rv = -EINVAL;
2326 goto out;
2327 }
2328 if (mddev->bitmap_info.external == 0 &&
2329 mddev->major_version == 0 &&
2330 offset != mddev->bitmap_info.default_offset) {
2331 rv = -EINVAL;
2332 goto out;
2333 }
2334 mddev->bitmap_info.offset = offset;
2335 if (mddev->pers) {
2336 struct bitmap *bitmap;
2337 bitmap = md_bitmap_create(mddev, -1);
2338 mddev_suspend(mddev);
2339 if (IS_ERR(bitmap))
2340 rv = PTR_ERR(bitmap);
2341 else {
2342 mddev->bitmap = bitmap;
2343 rv = md_bitmap_load(mddev);
2344 if (rv)
2345 mddev->bitmap_info.offset = 0;
2346 }
2347 if (rv) {
2348 md_bitmap_destroy(mddev);
2349 mddev_resume(mddev);
2350 goto out;
2351 }
2352 mddev_resume(mddev);
2353 }
2354 }
2355 }
2356 if (!mddev->external) {
2357 /* Ensure new bitmap info is stored in
2358 * metadata promptly.
2359 */
2360 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2361 md_wakeup_thread(mddev->thread);
2362 }
2363 rv = 0;
2364out:
2365 mddev_unlock(mddev);
2366 if (rv)
2367 return rv;
2368 return len;
2369}
2370
2371static struct md_sysfs_entry bitmap_location =
2372__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2373
2374/* 'bitmap/space' is the space available at 'location' for the
2375 * bitmap. This allows the kernel to know when it is safe to
2376 * resize the bitmap to match a resized array.
2377 */
2378static ssize_t
2379space_show(struct mddev *mddev, char *page)
2380{
2381 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2382}
2383
2384static ssize_t
2385space_store(struct mddev *mddev, const char *buf, size_t len)
2386{
2387 unsigned long sectors;
2388 int rv;
2389
2390 rv = kstrtoul(buf, 10, §ors);
2391 if (rv)
2392 return rv;
2393
2394 if (sectors == 0)
2395 return -EINVAL;
2396
2397 if (mddev->bitmap &&
2398 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2399 return -EFBIG; /* Bitmap is too big for this small space */
2400
2401 /* could make sure it isn't too big, but that isn't really
2402 * needed - user-space should be careful.
2403 */
2404 mddev->bitmap_info.space = sectors;
2405 return len;
2406}
2407
2408static struct md_sysfs_entry bitmap_space =
2409__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2410
2411static ssize_t
2412timeout_show(struct mddev *mddev, char *page)
2413{
2414 ssize_t len;
2415 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2416 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2417
2418 len = sprintf(page, "%lu", secs);
2419 if (jifs)
2420 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2421 len += sprintf(page+len, "\n");
2422 return len;
2423}
2424
2425static ssize_t
2426timeout_store(struct mddev *mddev, const char *buf, size_t len)
2427{
2428 /* timeout can be set at any time */
2429 unsigned long timeout;
2430 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2431 if (rv)
2432 return rv;
2433
2434 /* just to make sure we don't overflow... */
2435 if (timeout >= LONG_MAX / HZ)
2436 return -EINVAL;
2437
2438 timeout = timeout * HZ / 10000;
2439
2440 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2441 timeout = MAX_SCHEDULE_TIMEOUT-1;
2442 if (timeout < 1)
2443 timeout = 1;
2444 mddev->bitmap_info.daemon_sleep = timeout;
2445 if (mddev->thread) {
2446 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
2447 * the bitmap is all clean and we don't need to
2448 * adjust the timeout right now
2449 */
2450 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2451 mddev->thread->timeout = timeout;
2452 md_wakeup_thread(mddev->thread);
2453 }
2454 }
2455 return len;
2456}
2457
2458static struct md_sysfs_entry bitmap_timeout =
2459__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2460
2461static ssize_t
2462backlog_show(struct mddev *mddev, char *page)
2463{
2464 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2465}
2466
2467static ssize_t
2468backlog_store(struct mddev *mddev, const char *buf, size_t len)
2469{
2470 unsigned long backlog;
2471 unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
2472 int rv = kstrtoul(buf, 10, &backlog);
2473 if (rv)
2474 return rv;
2475 if (backlog > COUNTER_MAX)
2476 return -EINVAL;
2477 mddev->bitmap_info.max_write_behind = backlog;
2478 if (!backlog && mddev->wb_info_pool) {
2479 /* wb_info_pool is not needed if backlog is zero */
2480 mempool_destroy(mddev->wb_info_pool);
2481 mddev->wb_info_pool = NULL;
2482 } else if (backlog && !mddev->wb_info_pool) {
2483 /* wb_info_pool is needed since backlog is not zero */
2484 struct md_rdev *rdev;
2485
2486 rdev_for_each(rdev, mddev)
2487 mddev_create_wb_pool(mddev, rdev, false);
2488 }
2489 if (old_mwb != backlog)
2490 md_bitmap_update_sb(mddev->bitmap);
2491 return len;
2492}
2493
2494static struct md_sysfs_entry bitmap_backlog =
2495__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2496
2497static ssize_t
2498chunksize_show(struct mddev *mddev, char *page)
2499{
2500 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2501}
2502
2503static ssize_t
2504chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2505{
2506 /* Can only be changed when no bitmap is active */
2507 int rv;
2508 unsigned long csize;
2509 if (mddev->bitmap)
2510 return -EBUSY;
2511 rv = kstrtoul(buf, 10, &csize);
2512 if (rv)
2513 return rv;
2514 if (csize < 512 ||
2515 !is_power_of_2(csize))
2516 return -EINVAL;
2517 mddev->bitmap_info.chunksize = csize;
2518 return len;
2519}
2520
2521static struct md_sysfs_entry bitmap_chunksize =
2522__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2523
2524static ssize_t metadata_show(struct mddev *mddev, char *page)
2525{
2526 if (mddev_is_clustered(mddev))
2527 return sprintf(page, "clustered\n");
2528 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2529 ? "external" : "internal"));
2530}
2531
2532static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2533{
2534 if (mddev->bitmap ||
2535 mddev->bitmap_info.file ||
2536 mddev->bitmap_info.offset)
2537 return -EBUSY;
2538 if (strncmp(buf, "external", 8) == 0)
2539 mddev->bitmap_info.external = 1;
2540 else if ((strncmp(buf, "internal", 8) == 0) ||
2541 (strncmp(buf, "clustered", 9) == 0))
2542 mddev->bitmap_info.external = 0;
2543 else
2544 return -EINVAL;
2545 return len;
2546}
2547
2548static struct md_sysfs_entry bitmap_metadata =
2549__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2550
2551static ssize_t can_clear_show(struct mddev *mddev, char *page)
2552{
2553 int len;
2554 spin_lock(&mddev->lock);
2555 if (mddev->bitmap)
2556 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2557 "false" : "true"));
2558 else
2559 len = sprintf(page, "\n");
2560 spin_unlock(&mddev->lock);
2561 return len;
2562}
2563
2564static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2565{
2566 if (mddev->bitmap == NULL)
2567 return -ENOENT;
2568 if (strncmp(buf, "false", 5) == 0)
2569 mddev->bitmap->need_sync = 1;
2570 else if (strncmp(buf, "true", 4) == 0) {
2571 if (mddev->degraded)
2572 return -EBUSY;
2573 mddev->bitmap->need_sync = 0;
2574 } else
2575 return -EINVAL;
2576 return len;
2577}
2578
2579static struct md_sysfs_entry bitmap_can_clear =
2580__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2581
2582static ssize_t
2583behind_writes_used_show(struct mddev *mddev, char *page)
2584{
2585 ssize_t ret;
2586 spin_lock(&mddev->lock);
2587 if (mddev->bitmap == NULL)
2588 ret = sprintf(page, "0\n");
2589 else
2590 ret = sprintf(page, "%lu\n",
2591 mddev->bitmap->behind_writes_used);
2592 spin_unlock(&mddev->lock);
2593 return ret;
2594}
2595
2596static ssize_t
2597behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2598{
2599 if (mddev->bitmap)
2600 mddev->bitmap->behind_writes_used = 0;
2601 return len;
2602}
2603
2604static struct md_sysfs_entry max_backlog_used =
2605__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2606 behind_writes_used_show, behind_writes_used_reset);
2607
2608static struct attribute *md_bitmap_attrs[] = {
2609 &bitmap_location.attr,
2610 &bitmap_space.attr,
2611 &bitmap_timeout.attr,
2612 &bitmap_backlog.attr,
2613 &bitmap_chunksize.attr,
2614 &bitmap_metadata.attr,
2615 &bitmap_can_clear.attr,
2616 &max_backlog_used.attr,
2617 NULL
2618};
2619struct attribute_group md_bitmap_group = {
2620 .name = "bitmap",
2621 .attrs = md_bitmap_attrs,
2622};
2623