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
33#include "md.h"
34#include "md-bitmap.h"
35#include "md-cluster.h"
36
37/*
38 * in-memory bitmap:
39 *
40 * Use 16 bit block counters to track pending writes to each "chunk".
41 * The 2 high order bits are special-purpose, the first is a flag indicating
42 * whether a resync is needed. The second is a flag indicating whether a
43 * resync is active.
44 * This means that the counter is actually 14 bits:
45 *
46 * +--------+--------+------------------------------------------------+
47 * | resync | resync | counter |
48 * | needed | active | |
49 * | (0-1) | (0-1) | (0-16383) |
50 * +--------+--------+------------------------------------------------+
51 *
52 * The "resync needed" bit is set when:
53 * a '1' bit is read from storage at startup.
54 * a write request fails on some drives
55 * a resync is aborted on a chunk with 'resync active' set
56 * It is cleared (and resync-active set) when a resync starts across all drives
57 * of the chunk.
58 *
59 *
60 * The "resync active" bit is set when:
61 * a resync is started on all drives, and resync_needed is set.
62 * resync_needed will be cleared (as long as resync_active wasn't already set).
63 * It is cleared when a resync completes.
64 *
65 * The counter counts pending write requests, plus the on-disk bit.
66 * When the counter is '1' and the resync bits are clear, the on-disk
67 * bit can be cleared as well, thus setting the counter to 0.
68 * When we set a bit, or in the counter (to start a write), if the fields is
69 * 0, we first set the disk bit and set the counter to 1.
70 *
71 * If the counter is 0, the on-disk bit is clear and the stripe is clean
72 * Anything that dirties the stripe pushes the counter to 2 (at least)
73 * and sets the on-disk bit (lazily).
74 * If a periodic sweep find the counter at 2, it is decremented to 1.
75 * If the sweep find the counter at 1, the on-disk bit is cleared and the
76 * counter goes to zero.
77 *
78 * Also, we'll hijack the "map" pointer itself and use it as two 16 bit block
79 * counters as a fallback when "page" memory cannot be allocated:
80 *
81 * Normal case (page memory allocated):
82 *
83 * page pointer (32-bit)
84 *
85 * [ ] ------+
86 * |
87 * +-------> [ ][ ]..[ ] (4096 byte page == 2048 counters)
88 * c1 c2 c2048
89 *
90 * Hijacked case (page memory allocation failed):
91 *
92 * hijacked page pointer (32-bit)
93 *
94 * [ ][ ] (no page memory allocated)
95 * counter #1 (16-bit) counter #2 (16-bit)
96 *
97 */
98
99typedef __u16 bitmap_counter_t;
100
101#define PAGE_BITS (PAGE_SIZE << 3)
102#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3)
103
104#define COUNTER_BITS 16
105#define COUNTER_BIT_SHIFT 4
106#define COUNTER_BYTE_SHIFT (COUNTER_BIT_SHIFT - 3)
107
108#define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1)))
109#define RESYNC_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 2)))
110#define COUNTER_MAX ((bitmap_counter_t) RESYNC_MASK - 1)
111
112#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
113#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK)
114#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX)
115
116/* how many counters per page? */
117#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS)
118/* same, except a shift value for more efficient bitops */
119#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT)
120/* same, except a mask value for more efficient bitops */
121#define PAGE_COUNTER_MASK (PAGE_COUNTER_RATIO - 1)
122
123#define BITMAP_BLOCK_SHIFT 9
124
125/*
126 * bitmap structures:
127 */
128
129/* the in-memory bitmap is represented by bitmap_pages */
130struct bitmap_page {
131 /*
132 * map points to the actual memory page
133 */
134 char *map;
135 /*
136 * in emergencies (when map cannot be alloced), hijack the map
137 * pointer and use it as two counters itself
138 */
139 unsigned int hijacked:1;
140 /*
141 * If any counter in this page is '1' or '2' - and so could be
142 * cleared then that page is marked as 'pending'
143 */
144 unsigned int pending:1;
145 /*
146 * count of dirty bits on the page
147 */
148 unsigned int count:30;
149};
150
151/* the main bitmap structure - one per mddev */
152struct bitmap {
153
154 struct bitmap_counts {
155 spinlock_t lock;
156 struct bitmap_page *bp;
157 /* total number of pages in the bitmap */
158 unsigned long pages;
159 /* number of pages not yet allocated */
160 unsigned long missing_pages;
161 /* chunksize = 2^chunkshift (for bitops) */
162 unsigned long chunkshift;
163 /* total number of data chunks for the array */
164 unsigned long chunks;
165 } counts;
166
167 struct mddev *mddev; /* the md device that the bitmap is for */
168
169 __u64 events_cleared;
170 int need_sync;
171
172 struct bitmap_storage {
173 /* backing disk file */
174 struct file *file;
175 /* cached copy of the bitmap file superblock */
176 struct page *sb_page;
177 unsigned long sb_index;
178 /* list of cache pages for the file */
179 struct page **filemap;
180 /* attributes associated filemap pages */
181 unsigned long *filemap_attr;
182 /* number of pages in the file */
183 unsigned long file_pages;
184 /* total bytes in the bitmap */
185 unsigned long bytes;
186 } storage;
187
188 unsigned long flags;
189
190 int allclean;
191
192 atomic_t behind_writes;
193 /* highest actual value at runtime */
194 unsigned long behind_writes_used;
195
196 /*
197 * the bitmap daemon - periodically wakes up and sweeps the bitmap
198 * file, cleaning up bits and flushing out pages to disk as necessary
199 */
200 unsigned long daemon_lastrun; /* jiffies of last run */
201 /*
202 * when we lasted called end_sync to update bitmap with resync
203 * progress.
204 */
205 unsigned long last_end_sync;
206
207 /* pending writes to the bitmap file */
208 atomic_t pending_writes;
209 wait_queue_head_t write_wait;
210 wait_queue_head_t overflow_wait;
211 wait_queue_head_t behind_wait;
212
213 struct kernfs_node *sysfs_can_clear;
214 /* slot offset for clustered env */
215 int cluster_slot;
216};
217
218static struct workqueue_struct *md_bitmap_wq;
219
220static int __bitmap_resize(struct bitmap *bitmap, sector_t blocks,
221 int chunksize, bool init);
222
223static inline char *bmname(struct bitmap *bitmap)
224{
225 return bitmap->mddev ? mdname(mddev: bitmap->mddev) : "mdX";
226}
227
228static bool bitmap_enabled(void *data, bool flush)
229{
230 struct bitmap *bitmap = data;
231
232 if (!flush)
233 return true;
234
235 /*
236 * If caller want to flush bitmap pages to underlying disks, check if
237 * there are cached pages in filemap.
238 */
239 return !test_bit(BITMAP_STALE, &bitmap->flags) &&
240 bitmap->storage.filemap != NULL;
241}
242
243/*
244 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
245 *
246 * 1) check to see if this page is allocated, if it's not then try to alloc
247 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
248 * page pointer directly as a counter
249 *
250 * if we find our page, we increment the page's refcount so that it stays
251 * allocated while we're using it
252 */
253static int md_bitmap_checkpage(struct bitmap_counts *bitmap,
254 unsigned long page, int create, int no_hijack)
255__releases(bitmap->lock)
256__acquires(bitmap->lock)
257{
258 unsigned char *mappage;
259
260 WARN_ON_ONCE(page >= bitmap->pages);
261 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
262 return 0;
263
264 if (bitmap->bp[page].map) /* page is already allocated, just return */
265 return 0;
266
267 if (!create)
268 return -ENOENT;
269
270 /* this page has not been allocated yet */
271
272 spin_unlock_irq(lock: &bitmap->lock);
273 /* It is possible that this is being called inside a
274 * prepare_to_wait/finish_wait loop from raid5c:make_request().
275 * In general it is not permitted to sleep in that context as it
276 * can cause the loop to spin freely.
277 * That doesn't apply here as we can only reach this point
278 * once with any loop.
279 * When this function completes, either bp[page].map or
280 * bp[page].hijacked. In either case, this function will
281 * abort before getting to this point again. So there is
282 * no risk of a free-spin, and so it is safe to assert
283 * that sleeping here is allowed.
284 */
285 sched_annotate_sleep();
286 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
287 spin_lock_irq(lock: &bitmap->lock);
288
289 if (mappage == NULL) {
290 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
291 /* We don't support hijack for cluster raid */
292 if (no_hijack)
293 return -ENOMEM;
294 /* failed - set the hijacked flag so that we can use the
295 * pointer as a counter */
296 if (!bitmap->bp[page].map)
297 bitmap->bp[page].hijacked = 1;
298 } else if (bitmap->bp[page].map ||
299 bitmap->bp[page].hijacked) {
300 /* somebody beat us to getting the page */
301 kfree(objp: mappage);
302 } else {
303
304 /* no page was in place and we have one, so install it */
305
306 bitmap->bp[page].map = mappage;
307 bitmap->missing_pages--;
308 }
309 return 0;
310}
311
312/* if page is completely empty, put it back on the free list, or dealloc it */
313/* if page was hijacked, unmark the flag so it might get alloced next time */
314/* Note: lock should be held when calling this */
315static void md_bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
316{
317 char *ptr;
318
319 if (bitmap->bp[page].count) /* page is still busy */
320 return;
321
322 /* page is no longer in use, it can be released */
323
324 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
325 bitmap->bp[page].hijacked = 0;
326 bitmap->bp[page].map = NULL;
327 } else {
328 /* normal case, free the page */
329 ptr = bitmap->bp[page].map;
330 bitmap->bp[page].map = NULL;
331 bitmap->missing_pages++;
332 kfree(objp: ptr);
333 }
334}
335
336/*
337 * bitmap file handling - read and write the bitmap file and its superblock
338 */
339
340/*
341 * basic page I/O operations
342 */
343
344/* IO operations when bitmap is stored near all superblocks */
345
346/* choose a good rdev and read the page from there */
347static int read_sb_page(struct mddev *mddev, loff_t offset,
348 struct page *page, unsigned long index, int size)
349{
350
351 sector_t sector = mddev->bitmap_info.offset + offset +
352 index * (PAGE_SIZE / SECTOR_SIZE);
353 struct md_rdev *rdev;
354
355 rdev_for_each(rdev, mddev) {
356 u32 iosize = roundup(size, bdev_logical_block_size(rdev->bdev));
357
358 if (!test_bit(In_sync, &rdev->flags) ||
359 test_bit(Faulty, &rdev->flags) ||
360 test_bit(Bitmap_sync, &rdev->flags))
361 continue;
362
363 if (sync_page_io(rdev, sector, size: iosize, page, opf: REQ_OP_READ, metadata_op: true))
364 return 0;
365 }
366 return -EIO;
367}
368
369static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
370{
371 /* Iterate the disks of an mddev, using rcu to protect access to the
372 * linked list, and raising the refcount of devices we return to ensure
373 * they don't disappear while in use.
374 * As devices are only added or removed when raid_disk is < 0 and
375 * nr_pending is 0 and In_sync is clear, the entries we return will
376 * still be in the same position on the list when we re-enter
377 * list_for_each_entry_continue_rcu.
378 *
379 * Note that if entered with 'rdev == NULL' to start at the
380 * beginning, we temporarily assign 'rdev' to an address which
381 * isn't really an rdev, but which can be used by
382 * list_for_each_entry_continue_rcu() to find the first entry.
383 */
384 rcu_read_lock();
385 if (rdev == NULL)
386 /* start at the beginning */
387 rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
388 else {
389 /* release the previous rdev and start from there. */
390 rdev_dec_pending(rdev, mddev);
391 }
392 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
393 if (rdev->raid_disk >= 0 &&
394 !test_bit(Faulty, &rdev->flags)) {
395 /* this is a usable devices */
396 atomic_inc(v: &rdev->nr_pending);
397 rcu_read_unlock();
398 return rdev;
399 }
400 }
401 rcu_read_unlock();
402 return NULL;
403}
404
405static unsigned int optimal_io_size(struct block_device *bdev,
406 unsigned int last_page_size,
407 unsigned int io_size)
408{
409 if (bdev_io_opt(bdev) > bdev_logical_block_size(bdev))
410 return roundup(last_page_size, bdev_io_opt(bdev));
411 return io_size;
412}
413
414static unsigned int bitmap_io_size(unsigned int io_size, unsigned int opt_size,
415 loff_t start, loff_t boundary)
416{
417 if (io_size != opt_size &&
418 start + opt_size / SECTOR_SIZE <= boundary)
419 return opt_size;
420 if (start + io_size / SECTOR_SIZE <= boundary)
421 return io_size;
422
423 /* Overflows boundary */
424 return 0;
425}
426
427static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
428 unsigned long pg_index, struct page *page)
429{
430 struct block_device *bdev;
431 struct mddev *mddev = bitmap->mddev;
432 struct bitmap_storage *store = &bitmap->storage;
433 unsigned long num_pages = bitmap->storage.file_pages;
434 unsigned int bitmap_limit = (num_pages - pg_index % num_pages) << PAGE_SHIFT;
435 loff_t sboff, offset = mddev->bitmap_info.offset;
436 sector_t ps = pg_index * PAGE_SIZE / SECTOR_SIZE;
437 unsigned int size = PAGE_SIZE;
438 unsigned int opt_size = PAGE_SIZE;
439 sector_t doff;
440
441 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
442 /* we compare length (page numbers), not page offset. */
443 if ((pg_index - store->sb_index) == num_pages - 1) {
444 unsigned int last_page_size = store->bytes & (PAGE_SIZE - 1);
445
446 if (last_page_size == 0)
447 last_page_size = PAGE_SIZE;
448 size = roundup(last_page_size, bdev_logical_block_size(bdev));
449 opt_size = optimal_io_size(bdev, last_page_size, io_size: size);
450 }
451
452 sboff = rdev->sb_start + offset;
453 doff = rdev->data_offset;
454
455 /* Just make sure we aren't corrupting data or metadata */
456 if (mddev->external) {
457 /* Bitmap could be anywhere. */
458 if (sboff + ps > doff &&
459 sboff < (doff + mddev->dev_sectors + PAGE_SIZE / SECTOR_SIZE))
460 return -EINVAL;
461 } else if (offset < 0) {
462 /* DATA BITMAP METADATA */
463 size = bitmap_io_size(io_size: size, opt_size, start: offset + ps, boundary: 0);
464 if (size == 0)
465 /* bitmap runs in to metadata */
466 return -EINVAL;
467
468 if (doff + mddev->dev_sectors > sboff)
469 /* data runs in to bitmap */
470 return -EINVAL;
471 } else if (rdev->sb_start < rdev->data_offset) {
472 /* METADATA BITMAP DATA */
473 size = bitmap_io_size(io_size: size, opt_size, start: sboff + ps, boundary: doff);
474 if (size == 0)
475 /* bitmap runs in to data */
476 return -EINVAL;
477 }
478
479 md_write_metadata(mddev, rdev, sector: sboff + ps, size: (int)min(size, bitmap_limit),
480 page, offset: 0);
481 return 0;
482}
483
484static void write_sb_page(struct bitmap *bitmap, unsigned long pg_index,
485 struct page *page, bool wait)
486{
487 struct mddev *mddev = bitmap->mddev;
488
489 do {
490 struct md_rdev *rdev = NULL;
491
492 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
493 if (__write_sb_page(rdev, bitmap, pg_index, page) < 0) {
494 set_bit(nr: BITMAP_WRITE_ERROR, addr: &bitmap->flags);
495 return;
496 }
497 }
498 } while (wait && md_super_wait(mddev) < 0);
499}
500
501static void md_bitmap_file_kick(struct bitmap *bitmap);
502
503#ifdef CONFIG_MD_BITMAP_FILE
504static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
505{
506 struct buffer_head *bh = page_buffers(page);
507
508 while (bh && bh->b_blocknr) {
509 atomic_inc(v: &bitmap->pending_writes);
510 set_buffer_locked(bh);
511 set_buffer_mapped(bh);
512 submit_bh(REQ_OP_WRITE | REQ_SYNC, bh);
513 bh = bh->b_this_page;
514 }
515
516 if (wait)
517 wait_event(bitmap->write_wait,
518 atomic_read(&bitmap->pending_writes) == 0);
519}
520
521static void end_bitmap_write(struct buffer_head *bh, int uptodate)
522{
523 struct bitmap *bitmap = bh->b_private;
524
525 if (!uptodate)
526 set_bit(nr: BITMAP_WRITE_ERROR, addr: &bitmap->flags);
527 if (atomic_dec_and_test(v: &bitmap->pending_writes))
528 wake_up(&bitmap->write_wait);
529}
530
531static void free_buffers(struct page *page)
532{
533 struct buffer_head *bh;
534
535 if (!PagePrivate(page))
536 return;
537
538 bh = page_buffers(page);
539 while (bh) {
540 struct buffer_head *next = bh->b_this_page;
541 free_buffer_head(bh);
542 bh = next;
543 }
544 detach_page_private(page);
545 put_page(page);
546}
547
548/* read a page from a file.
549 * We both read the page, and attach buffers to the page to record the
550 * address of each block (using bmap). These addresses will be used
551 * to write the block later, completely bypassing the filesystem.
552 * This usage is similar to how swap files are handled, and allows us
553 * to write to a file with no concerns of memory allocation failing.
554 */
555static int read_file_page(struct file *file, unsigned long index,
556 struct bitmap *bitmap, unsigned long count, struct page *page)
557{
558 int ret = 0;
559 struct inode *inode = file_inode(f: file);
560 struct buffer_head *bh;
561 sector_t block, blk_cur;
562 unsigned long blocksize = i_blocksize(node: inode);
563
564 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
565 (unsigned long long)index << PAGE_SHIFT);
566
567 bh = alloc_page_buffers(page, size: blocksize);
568 if (!bh) {
569 ret = -ENOMEM;
570 goto out;
571 }
572 attach_page_private(page, data: bh);
573 blk_cur = index << (PAGE_SHIFT - inode->i_blkbits);
574 while (bh) {
575 block = blk_cur;
576
577 if (count == 0)
578 bh->b_blocknr = 0;
579 else {
580 ret = bmap(inode, block: &block);
581 if (ret || !block) {
582 ret = -EINVAL;
583 bh->b_blocknr = 0;
584 goto out;
585 }
586
587 bh->b_blocknr = block;
588 bh->b_bdev = inode->i_sb->s_bdev;
589 if (count < blocksize)
590 count = 0;
591 else
592 count -= blocksize;
593
594 bh->b_end_io = end_bitmap_write;
595 bh->b_private = bitmap;
596 atomic_inc(v: &bitmap->pending_writes);
597 set_buffer_locked(bh);
598 set_buffer_mapped(bh);
599 submit_bh(REQ_OP_READ, bh);
600 }
601 blk_cur++;
602 bh = bh->b_this_page;
603 }
604
605 wait_event(bitmap->write_wait,
606 atomic_read(&bitmap->pending_writes)==0);
607 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
608 ret = -EIO;
609out:
610 if (ret)
611 pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
612 (int)PAGE_SIZE,
613 (unsigned long long)index << PAGE_SHIFT,
614 ret);
615 return ret;
616}
617#else /* CONFIG_MD_BITMAP_FILE */
618static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
619{
620}
621static int read_file_page(struct file *file, unsigned long index,
622 struct bitmap *bitmap, unsigned long count, struct page *page)
623{
624 return -EIO;
625}
626static void free_buffers(struct page *page)
627{
628 put_page(page);
629}
630#endif /* CONFIG_MD_BITMAP_FILE */
631
632/*
633 * bitmap file superblock operations
634 */
635
636/*
637 * write out a page to a file
638 */
639static void filemap_write_page(struct bitmap *bitmap, unsigned long pg_index,
640 bool wait)
641{
642 struct bitmap_storage *store = &bitmap->storage;
643 struct page *page = store->filemap[pg_index];
644
645 if (mddev_is_clustered(mddev: bitmap->mddev)) {
646 /* go to node bitmap area starting point */
647 pg_index += store->sb_index;
648 }
649
650 if (store->file)
651 write_file_page(bitmap, page, wait);
652 else
653 write_sb_page(bitmap, pg_index, page, wait);
654}
655
656/*
657 * md_bitmap_wait_writes() should be called before writing any bitmap
658 * blocks, to ensure previous writes, particularly from
659 * md_bitmap_daemon_work(), have completed.
660 */
661static void md_bitmap_wait_writes(struct bitmap *bitmap)
662{
663 if (bitmap->storage.file)
664 wait_event(bitmap->write_wait,
665 atomic_read(&bitmap->pending_writes)==0);
666 else
667 /* Note that we ignore the return value. The writes
668 * might have failed, but that would just mean that
669 * some bits which should be cleared haven't been,
670 * which is safe. The relevant bitmap blocks will
671 * probably get written again, but there is no great
672 * loss if they aren't.
673 */
674 md_super_wait(mddev: bitmap->mddev);
675}
676
677
678/* update the event counter and sync the superblock to disk */
679static void bitmap_update_sb(void *data)
680{
681 bitmap_super_t *sb;
682 struct bitmap *bitmap = data;
683
684 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
685 return;
686 if (bitmap->mddev->bitmap_info.external)
687 return;
688 if (!bitmap->storage.sb_page) /* no superblock */
689 return;
690 sb = kmap_local_page(page: bitmap->storage.sb_page);
691 sb->events = cpu_to_le64(bitmap->mddev->events);
692 if (bitmap->mddev->events < bitmap->events_cleared)
693 /* rocking back to read-only */
694 bitmap->events_cleared = bitmap->mddev->events;
695 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
696 /*
697 * clear BITMAP_WRITE_ERROR bit to protect against the case that
698 * a bitmap write error occurred but the later writes succeeded.
699 */
700 sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR));
701 /* Just in case these have been changed via sysfs: */
702 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
703 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
704 /* This might have been changed by a reshape */
705 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
706 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
707 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
708 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
709 bitmap_info.space);
710 kunmap_local(sb);
711
712 if (bitmap->storage.file)
713 write_file_page(bitmap, page: bitmap->storage.sb_page, wait: 1);
714 else
715 write_sb_page(bitmap, pg_index: bitmap->storage.sb_index,
716 page: bitmap->storage.sb_page, wait: 1);
717}
718
719static void bitmap_print_sb(struct bitmap *bitmap)
720{
721 bitmap_super_t *sb;
722
723 if (!bitmap || !bitmap->storage.sb_page)
724 return;
725 sb = kmap_local_page(page: bitmap->storage.sb_page);
726 pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
727 pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic));
728 pr_debug(" version: %u\n", le32_to_cpu(sb->version));
729 pr_debug(" uuid: %08x.%08x.%08x.%08x\n",
730 le32_to_cpu(*(__le32 *)(sb->uuid+0)),
731 le32_to_cpu(*(__le32 *)(sb->uuid+4)),
732 le32_to_cpu(*(__le32 *)(sb->uuid+8)),
733 le32_to_cpu(*(__le32 *)(sb->uuid+12)));
734 pr_debug(" events: %llu\n",
735 (unsigned long long) le64_to_cpu(sb->events));
736 pr_debug("events cleared: %llu\n",
737 (unsigned long long) le64_to_cpu(sb->events_cleared));
738 pr_debug(" state: %08x\n", le32_to_cpu(sb->state));
739 pr_debug(" chunksize: %u B\n", le32_to_cpu(sb->chunksize));
740 pr_debug(" daemon sleep: %us\n", le32_to_cpu(sb->daemon_sleep));
741 pr_debug(" sync size: %llu KB\n",
742 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
743 pr_debug("max write behind: %u\n", le32_to_cpu(sb->write_behind));
744 kunmap_local(sb);
745}
746
747/*
748 * bitmap_new_disk_sb
749 * @bitmap
750 *
751 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
752 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
753 * This function verifies 'bitmap_info' and populates the on-disk bitmap
754 * structure, which is to be written to disk.
755 *
756 * Returns: 0 on success, -Exxx on error
757 */
758static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
759{
760 bitmap_super_t *sb;
761 unsigned long chunksize, daemon_sleep, write_behind;
762
763 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
764 if (bitmap->storage.sb_page == NULL)
765 return -ENOMEM;
766 bitmap->storage.sb_index = 0;
767
768 sb = kmap_local_page(page: bitmap->storage.sb_page);
769
770 sb->magic = cpu_to_le32(BITMAP_MAGIC);
771 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
772
773 chunksize = bitmap->mddev->bitmap_info.chunksize;
774 BUG_ON(!chunksize);
775 if (!is_power_of_2(n: chunksize)) {
776 kunmap_local(sb);
777 pr_warn("bitmap chunksize not a power of 2\n");
778 return -EINVAL;
779 }
780 sb->chunksize = cpu_to_le32(chunksize);
781
782 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
783 if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
784 pr_debug("Choosing daemon_sleep default (5 sec)\n");
785 daemon_sleep = 5 * HZ;
786 }
787 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
788 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
789
790 /*
791 * FIXME: write_behind for RAID1. If not specified, what
792 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
793 */
794 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
795 if (write_behind > COUNTER_MAX / 2)
796 write_behind = COUNTER_MAX / 2;
797 sb->write_behind = cpu_to_le32(write_behind);
798 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
799
800 /* keep the array size field of the bitmap superblock up to date */
801 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
802
803 memcpy(to: sb->uuid, from: bitmap->mddev->uuid, len: 16);
804
805 set_bit(nr: BITMAP_STALE, addr: &bitmap->flags);
806 sb->state = cpu_to_le32(bitmap->flags);
807 bitmap->events_cleared = bitmap->mddev->events;
808 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
809 bitmap->mddev->bitmap_info.nodes = 0;
810
811 kunmap_local(sb);
812
813 return 0;
814}
815
816/* read the superblock from the bitmap file and initialize some bitmap fields */
817static int md_bitmap_read_sb(struct bitmap *bitmap)
818{
819 char *reason = NULL;
820 bitmap_super_t *sb;
821 unsigned long chunksize, daemon_sleep, write_behind;
822 unsigned long long events;
823 int nodes = 0;
824 unsigned long sectors_reserved = 0;
825 int err = -EINVAL;
826 struct page *sb_page;
827 loff_t offset = 0;
828
829 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
830 chunksize = 128 * 1024 * 1024;
831 daemon_sleep = 5 * HZ;
832 write_behind = 0;
833 set_bit(nr: BITMAP_STALE, addr: &bitmap->flags);
834 err = 0;
835 goto out_no_sb;
836 }
837 /* page 0 is the superblock, read it... */
838 sb_page = alloc_page(GFP_KERNEL);
839 if (!sb_page)
840 return -ENOMEM;
841 bitmap->storage.sb_page = sb_page;
842
843re_read:
844 /* If cluster_slot is set, the cluster is setup */
845 if (bitmap->cluster_slot >= 0) {
846 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
847
848 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks,
849 (bitmap->mddev->bitmap_info.chunksize >> 9));
850 /* bits to bytes */
851 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
852 /* to 4k blocks */
853 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
854 offset = bitmap->cluster_slot * (bm_blocks << 3);
855 pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
856 bitmap->cluster_slot, offset);
857 }
858
859 if (bitmap->storage.file) {
860 loff_t isize = i_size_read(inode: bitmap->storage.file->f_mapping->host);
861 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
862
863 err = read_file_page(file: bitmap->storage.file, index: 0,
864 bitmap, count: bytes, page: sb_page);
865 } else {
866 err = read_sb_page(mddev: bitmap->mddev, offset, page: sb_page, index: 0,
867 size: sizeof(bitmap_super_t));
868 }
869 if (err)
870 return err;
871
872 err = -EINVAL;
873 sb = kmap_local_page(page: sb_page);
874
875 chunksize = le32_to_cpu(sb->chunksize);
876 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
877 write_behind = le32_to_cpu(sb->write_behind);
878 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
879
880 /* verify that the bitmap-specific fields are valid */
881 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
882 reason = "bad magic";
883 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
884 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
885 reason = "unrecognized superblock version";
886 else if (chunksize < 512)
887 reason = "bitmap chunksize too small";
888 else if (!is_power_of_2(n: chunksize))
889 reason = "bitmap chunksize not a power of 2";
890 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
891 reason = "daemon sleep period out of range";
892 else if (write_behind > COUNTER_MAX)
893 reason = "write-behind limit out of range (0 - 16383)";
894 if (reason) {
895 pr_warn("%s: invalid bitmap file superblock: %s\n",
896 bmname(bitmap), reason);
897 goto out;
898 }
899
900 /*
901 * Setup nodes/clustername only if bitmap version is
902 * cluster-compatible
903 */
904 if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
905 nodes = le32_to_cpu(sb->nodes);
906 strscpy(bitmap->mddev->bitmap_info.cluster_name,
907 sb->cluster_name, 64);
908 }
909
910 /* keep the array size field of the bitmap superblock up to date */
911 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
912
913 if (bitmap->mddev->persistent) {
914 /*
915 * We have a persistent array superblock, so compare the
916 * bitmap's UUID and event counter to the mddev's
917 */
918 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
919 pr_warn("%s: bitmap superblock UUID mismatch\n",
920 bmname(bitmap));
921 goto out;
922 }
923 events = le64_to_cpu(sb->events);
924 if (!nodes && (events < bitmap->mddev->events)) {
925 pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
926 bmname(bitmap), events,
927 (unsigned long long) bitmap->mddev->events);
928 set_bit(nr: BITMAP_STALE, addr: &bitmap->flags);
929 }
930 }
931
932 /* assign fields using values from superblock */
933 bitmap->flags |= le32_to_cpu(sb->state);
934 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
935 set_bit(nr: BITMAP_HOSTENDIAN, addr: &bitmap->flags);
936 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
937 err = 0;
938
939out:
940 kunmap_local(sb);
941 if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
942 /* Assigning chunksize is required for "re_read" */
943 bitmap->mddev->bitmap_info.chunksize = chunksize;
944 err = md_setup_cluster(mddev: bitmap->mddev, nodes);
945 if (err) {
946 pr_warn("%s: Could not setup cluster service (%d)\n",
947 bmname(bitmap), err);
948 goto out_no_sb;
949 }
950 bitmap->cluster_slot = bitmap->mddev->cluster_ops->slot_number(bitmap->mddev);
951 goto re_read;
952 }
953
954out_no_sb:
955 if (err == 0) {
956 if (test_bit(BITMAP_STALE, &bitmap->flags))
957 bitmap->events_cleared = bitmap->mddev->events;
958 bitmap->mddev->bitmap_info.chunksize = chunksize;
959 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
960 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
961 bitmap->mddev->bitmap_info.nodes = nodes;
962 if (bitmap->mddev->bitmap_info.space == 0 ||
963 bitmap->mddev->bitmap_info.space > sectors_reserved)
964 bitmap->mddev->bitmap_info.space = sectors_reserved;
965 } else {
966 bitmap_print_sb(bitmap);
967 if (bitmap->cluster_slot < 0)
968 md_cluster_stop(mddev: bitmap->mddev);
969 }
970 return err;
971}
972
973/*
974 * general bitmap file operations
975 */
976
977/*
978 * on-disk bitmap:
979 *
980 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
981 * file a page at a time. There's a superblock at the start of the file.
982 */
983/* calculate the index of the page that contains this bit */
984static inline unsigned long file_page_index(struct bitmap_storage *store,
985 unsigned long chunk)
986{
987 if (store->sb_page)
988 chunk += sizeof(bitmap_super_t) << 3;
989 return chunk >> PAGE_BIT_SHIFT;
990}
991
992/* calculate the (bit) offset of this bit within a page */
993static inline unsigned long file_page_offset(struct bitmap_storage *store,
994 unsigned long chunk)
995{
996 if (store->sb_page)
997 chunk += sizeof(bitmap_super_t) << 3;
998 return chunk & (PAGE_BITS - 1);
999}
1000
1001/*
1002 * return a pointer to the page in the filemap that contains the given bit
1003 *
1004 */
1005static inline struct page *filemap_get_page(struct bitmap_storage *store,
1006 unsigned long chunk)
1007{
1008 if (file_page_index(store, chunk) >= store->file_pages)
1009 return NULL;
1010 return store->filemap[file_page_index(store, chunk)];
1011}
1012
1013static int md_bitmap_storage_alloc(struct bitmap_storage *store,
1014 unsigned long chunks, int with_super,
1015 int slot_number)
1016{
1017 int pnum, offset = 0;
1018 unsigned long num_pages;
1019 unsigned long bytes;
1020
1021 bytes = DIV_ROUND_UP(chunks, 8);
1022 if (with_super)
1023 bytes += sizeof(bitmap_super_t);
1024
1025 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
1026 offset = slot_number * num_pages;
1027
1028 store->filemap = kmalloc_array(num_pages, sizeof(struct page *),
1029 GFP_KERNEL);
1030 if (!store->filemap)
1031 return -ENOMEM;
1032
1033 if (with_super && !store->sb_page) {
1034 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
1035 if (store->sb_page == NULL)
1036 return -ENOMEM;
1037 }
1038
1039 pnum = 0;
1040 if (store->sb_page) {
1041 store->filemap[0] = store->sb_page;
1042 pnum = 1;
1043 store->sb_index = offset;
1044 }
1045
1046 for ( ; pnum < num_pages; pnum++) {
1047 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
1048 if (!store->filemap[pnum]) {
1049 store->file_pages = pnum;
1050 return -ENOMEM;
1051 }
1052 }
1053 store->file_pages = pnum;
1054
1055 /* We need 4 bits per page, rounded up to a multiple
1056 * of sizeof(unsigned long) */
1057 store->filemap_attr = kzalloc(
1058 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
1059 GFP_KERNEL);
1060 if (!store->filemap_attr)
1061 return -ENOMEM;
1062
1063 store->bytes = bytes;
1064
1065 return 0;
1066}
1067
1068static void md_bitmap_file_unmap(struct bitmap_storage *store)
1069{
1070 struct file *file = store->file;
1071 struct page *sb_page = store->sb_page;
1072 struct page **map = store->filemap;
1073 int pages = store->file_pages;
1074
1075 while (pages--)
1076 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
1077 free_buffers(page: map[pages]);
1078 kfree(objp: map);
1079 kfree(objp: store->filemap_attr);
1080
1081 if (sb_page)
1082 free_buffers(page: sb_page);
1083
1084 if (file) {
1085 struct inode *inode = file_inode(f: file);
1086 invalidate_mapping_pages(mapping: inode->i_mapping, start: 0, end: -1);
1087 fput(file);
1088 }
1089}
1090
1091/*
1092 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
1093 * then it is no longer reliable, so we stop using it and we mark the file
1094 * as failed in the superblock
1095 */
1096static void md_bitmap_file_kick(struct bitmap *bitmap)
1097{
1098 if (!test_and_set_bit(nr: BITMAP_STALE, addr: &bitmap->flags)) {
1099 bitmap_update_sb(data: bitmap);
1100
1101 if (bitmap->storage.file) {
1102 pr_warn("%s: kicking failed bitmap file %pD4 from array!\n",
1103 bmname(bitmap), bitmap->storage.file);
1104
1105 } else
1106 pr_warn("%s: disabling internal bitmap due to errors\n",
1107 bmname(bitmap));
1108 }
1109}
1110
1111enum bitmap_page_attr {
1112 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
1113 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
1114 * i.e. counter is 1 or 2. */
1115 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
1116};
1117
1118static inline void set_page_attr(struct bitmap *bitmap, int pnum,
1119 enum bitmap_page_attr attr)
1120{
1121 set_bit(nr: (pnum<<2) + attr, addr: bitmap->storage.filemap_attr);
1122}
1123
1124static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
1125 enum bitmap_page_attr attr)
1126{
1127 clear_bit(nr: (pnum<<2) + attr, addr: bitmap->storage.filemap_attr);
1128}
1129
1130static inline int test_page_attr(struct bitmap *bitmap, int pnum,
1131 enum bitmap_page_attr attr)
1132{
1133 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
1134}
1135
1136static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
1137 enum bitmap_page_attr attr)
1138{
1139 return test_and_clear_bit(nr: (pnum<<2) + attr,
1140 addr: bitmap->storage.filemap_attr);
1141}
1142/*
1143 * bitmap_file_set_bit -- called before performing a write to the md device
1144 * to set (and eventually sync) a particular bit in the bitmap file
1145 *
1146 * we set the bit immediately, then we record the page number so that
1147 * when an unplug occurs, we can flush the dirty pages out to disk
1148 */
1149static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
1150{
1151 unsigned long bit;
1152 struct page *page;
1153 void *kaddr;
1154 unsigned long chunk = block >> bitmap->counts.chunkshift;
1155 struct bitmap_storage *store = &bitmap->storage;
1156 unsigned long index = file_page_index(store, chunk);
1157 unsigned long node_offset = 0;
1158
1159 index += store->sb_index;
1160 if (mddev_is_clustered(mddev: bitmap->mddev))
1161 node_offset = bitmap->cluster_slot * store->file_pages;
1162
1163 page = filemap_get_page(store: &bitmap->storage, chunk);
1164 if (!page)
1165 return;
1166 bit = file_page_offset(store: &bitmap->storage, chunk);
1167
1168 /* set the bit */
1169 kaddr = kmap_local_page(page);
1170 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1171 set_bit(nr: bit, addr: kaddr);
1172 else
1173 set_bit_le(nr: bit, addr: kaddr);
1174 kunmap_local(kaddr);
1175 pr_debug("set file bit %lu page %lu\n", bit, index);
1176 /* record page number so it gets flushed to disk when unplug occurs */
1177 set_page_attr(bitmap, pnum: index - node_offset, attr: BITMAP_PAGE_DIRTY);
1178}
1179
1180static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
1181{
1182 unsigned long bit;
1183 struct page *page;
1184 void *paddr;
1185 unsigned long chunk = block >> bitmap->counts.chunkshift;
1186 struct bitmap_storage *store = &bitmap->storage;
1187 unsigned long index = file_page_index(store, chunk);
1188 unsigned long node_offset = 0;
1189
1190 index += store->sb_index;
1191 if (mddev_is_clustered(mddev: bitmap->mddev))
1192 node_offset = bitmap->cluster_slot * store->file_pages;
1193
1194 page = filemap_get_page(store: &bitmap->storage, chunk);
1195 if (!page)
1196 return;
1197 bit = file_page_offset(store: &bitmap->storage, chunk);
1198 paddr = kmap_local_page(page);
1199 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1200 clear_bit(nr: bit, addr: paddr);
1201 else
1202 clear_bit_le(nr: bit, addr: paddr);
1203 kunmap_local(paddr);
1204 if (!test_page_attr(bitmap, pnum: index - node_offset, attr: BITMAP_PAGE_NEEDWRITE)) {
1205 set_page_attr(bitmap, pnum: index - node_offset, attr: BITMAP_PAGE_PENDING);
1206 bitmap->allclean = 0;
1207 }
1208}
1209
1210static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
1211{
1212 unsigned long bit;
1213 struct page *page;
1214 void *paddr;
1215 unsigned long chunk = block >> bitmap->counts.chunkshift;
1216 int set = 0;
1217
1218 page = filemap_get_page(store: &bitmap->storage, chunk);
1219 if (!page)
1220 return -EINVAL;
1221 bit = file_page_offset(store: &bitmap->storage, chunk);
1222 paddr = kmap_local_page(page);
1223 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1224 set = test_bit(bit, paddr);
1225 else
1226 set = test_bit_le(nr: bit, addr: paddr);
1227 kunmap_local(paddr);
1228 return set;
1229}
1230
1231/* this gets called when the md device is ready to unplug its underlying
1232 * (slave) device queues -- before we let any writes go down, we need to
1233 * sync the dirty pages of the bitmap file to disk */
1234static void __bitmap_unplug(struct bitmap *bitmap)
1235{
1236 unsigned long i;
1237 int dirty, need_write;
1238 int writing = 0;
1239
1240 if (!bitmap_enabled(data: bitmap, flush: true))
1241 return;
1242
1243 /* look at each page to see if there are any set bits that need to be
1244 * flushed out to disk */
1245 for (i = 0; i < bitmap->storage.file_pages; i++) {
1246 dirty = test_and_clear_page_attr(bitmap, pnum: i, attr: BITMAP_PAGE_DIRTY);
1247 need_write = test_and_clear_page_attr(bitmap, pnum: i,
1248 attr: BITMAP_PAGE_NEEDWRITE);
1249 if (dirty || need_write) {
1250 if (!writing) {
1251 md_bitmap_wait_writes(bitmap);
1252 mddev_add_trace_msg(bitmap->mddev,
1253 "md bitmap_unplug");
1254 }
1255 clear_page_attr(bitmap, pnum: i, attr: BITMAP_PAGE_PENDING);
1256 filemap_write_page(bitmap, pg_index: i, wait: false);
1257 writing = 1;
1258 }
1259 }
1260 if (writing)
1261 md_bitmap_wait_writes(bitmap);
1262
1263 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1264 md_bitmap_file_kick(bitmap);
1265}
1266
1267struct bitmap_unplug_work {
1268 struct work_struct work;
1269 struct bitmap *bitmap;
1270 struct completion *done;
1271};
1272
1273static void md_bitmap_unplug_fn(struct work_struct *work)
1274{
1275 struct bitmap_unplug_work *unplug_work =
1276 container_of(work, struct bitmap_unplug_work, work);
1277
1278 __bitmap_unplug(bitmap: unplug_work->bitmap);
1279 complete(unplug_work->done);
1280}
1281
1282static void bitmap_unplug_async(struct bitmap *bitmap)
1283{
1284 DECLARE_COMPLETION_ONSTACK(done);
1285 struct bitmap_unplug_work unplug_work;
1286
1287 INIT_WORK_ONSTACK(&unplug_work.work, md_bitmap_unplug_fn);
1288 unplug_work.bitmap = bitmap;
1289 unplug_work.done = &done;
1290
1291 queue_work(wq: md_bitmap_wq, work: &unplug_work.work);
1292 wait_for_completion(&done);
1293 destroy_work_on_stack(work: &unplug_work.work);
1294}
1295
1296static void bitmap_unplug(struct mddev *mddev, bool sync)
1297{
1298 struct bitmap *bitmap = mddev->bitmap;
1299
1300 if (!bitmap)
1301 return;
1302
1303 if (sync)
1304 __bitmap_unplug(bitmap);
1305 else
1306 bitmap_unplug_async(bitmap);
1307}
1308
1309static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1310
1311/*
1312 * Initialize the in-memory bitmap from the on-disk bitmap and set up the memory
1313 * mapping of the bitmap file.
1314 *
1315 * Special case: If there's no bitmap file, or if the bitmap file had been
1316 * previously kicked from the array, we mark all the bits as 1's in order to
1317 * cause a full resync.
1318 *
1319 * We ignore all bits for sectors that end earlier than 'start'.
1320 * This is used when reading an out-of-date bitmap.
1321 */
1322static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1323{
1324 bool outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1325 struct mddev *mddev = bitmap->mddev;
1326 unsigned long chunks = bitmap->counts.chunks;
1327 struct bitmap_storage *store = &bitmap->storage;
1328 struct file *file = store->file;
1329 unsigned long node_offset = 0;
1330 unsigned long bit_cnt = 0;
1331 unsigned long i;
1332 int ret;
1333
1334 if (!file && !mddev->bitmap_info.offset) {
1335 /* No permanent bitmap - fill with '1s'. */
1336 store->filemap = NULL;
1337 store->file_pages = 0;
1338 for (i = 0; i < chunks ; i++) {
1339 /* if the disk bit is set, set the memory bit */
1340 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1341 >= start);
1342 md_bitmap_set_memory_bits(bitmap,
1343 offset: (sector_t)i << bitmap->counts.chunkshift,
1344 needed);
1345 }
1346 return 0;
1347 }
1348
1349 if (file && i_size_read(inode: file->f_mapping->host) < store->bytes) {
1350 pr_warn("%s: bitmap file too short %lu < %lu\n",
1351 bmname(bitmap),
1352 (unsigned long) i_size_read(file->f_mapping->host),
1353 store->bytes);
1354 ret = -ENOSPC;
1355 goto err;
1356 }
1357
1358 if (mddev_is_clustered(mddev))
1359 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1360
1361 for (i = 0; i < store->file_pages; i++) {
1362 struct page *page = store->filemap[i];
1363 int count;
1364
1365 /* unmap the old page, we're done with it */
1366 if (i == store->file_pages - 1)
1367 count = store->bytes - i * PAGE_SIZE;
1368 else
1369 count = PAGE_SIZE;
1370
1371 if (file)
1372 ret = read_file_page(file, index: i, bitmap, count, page);
1373 else
1374 ret = read_sb_page(mddev, offset: 0, page, index: i + node_offset,
1375 size: count);
1376 if (ret)
1377 goto err;
1378 }
1379
1380 if (outofdate) {
1381 pr_warn("%s: bitmap file is out of date, doing full recovery\n",
1382 bmname(bitmap));
1383
1384 for (i = 0; i < store->file_pages; i++) {
1385 struct page *page = store->filemap[i];
1386 unsigned long offset = 0;
1387 void *paddr;
1388
1389 if (i == 0 && !mddev->bitmap_info.external)
1390 offset = sizeof(bitmap_super_t);
1391
1392 /*
1393 * If the bitmap is out of date, dirty the whole page
1394 * and write it out
1395 */
1396 paddr = kmap_local_page(page);
1397 memset(s: paddr + offset, c: 0xff, PAGE_SIZE - offset);
1398 kunmap_local(paddr);
1399
1400 filemap_write_page(bitmap, pg_index: i, wait: true);
1401 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags)) {
1402 ret = -EIO;
1403 goto err;
1404 }
1405 }
1406 }
1407
1408 for (i = 0; i < chunks; i++) {
1409 struct page *page = filemap_get_page(store: &bitmap->storage, chunk: i);
1410 unsigned long bit = file_page_offset(store: &bitmap->storage, chunk: i);
1411 void *paddr;
1412 bool was_set;
1413
1414 paddr = kmap_local_page(page);
1415 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1416 was_set = test_bit(bit, paddr);
1417 else
1418 was_set = test_bit_le(nr: bit, addr: paddr);
1419 kunmap_local(paddr);
1420
1421 if (was_set) {
1422 /* if the disk bit is set, set the memory bit */
1423 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1424 >= start);
1425 md_bitmap_set_memory_bits(bitmap,
1426 offset: (sector_t)i << bitmap->counts.chunkshift,
1427 needed);
1428 bit_cnt++;
1429 }
1430 }
1431
1432 pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
1433 bmname(bitmap), store->file_pages,
1434 bit_cnt, chunks);
1435
1436 return 0;
1437
1438 err:
1439 pr_warn("%s: bitmap initialisation failed: %d\n",
1440 bmname(bitmap), ret);
1441 return ret;
1442}
1443
1444/* just flag bitmap pages as needing to be written. */
1445static void bitmap_write_all(struct mddev *mddev)
1446{
1447 int i;
1448 struct bitmap *bitmap = mddev->bitmap;
1449
1450 if (!bitmap || !bitmap->storage.filemap)
1451 return;
1452
1453 /* Only one copy, so nothing needed */
1454 if (bitmap->storage.file)
1455 return;
1456
1457 for (i = 0; i < bitmap->storage.file_pages; i++)
1458 set_page_attr(bitmap, pnum: i, attr: BITMAP_PAGE_NEEDWRITE);
1459 bitmap->allclean = 0;
1460}
1461
1462static void md_bitmap_count_page(struct bitmap_counts *bitmap,
1463 sector_t offset, int inc)
1464{
1465 sector_t chunk = offset >> bitmap->chunkshift;
1466 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1467 bitmap->bp[page].count += inc;
1468 md_bitmap_checkfree(bitmap, page);
1469}
1470
1471static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1472{
1473 sector_t chunk = offset >> bitmap->chunkshift;
1474 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1475 struct bitmap_page *bp = &bitmap->bp[page];
1476
1477 if (!bp->pending)
1478 bp->pending = 1;
1479}
1480
1481static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1482 sector_t offset, sector_t *blocks,
1483 int create);
1484
1485static void mddev_set_timeout(struct mddev *mddev, unsigned long timeout,
1486 bool force)
1487{
1488 struct md_thread *thread;
1489
1490 rcu_read_lock();
1491 thread = rcu_dereference(mddev->thread);
1492
1493 if (!thread)
1494 goto out;
1495
1496 if (force || thread->timeout < MAX_SCHEDULE_TIMEOUT)
1497 thread->timeout = timeout;
1498
1499out:
1500 rcu_read_unlock();
1501}
1502
1503/*
1504 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1505 * out to disk
1506 */
1507static void bitmap_daemon_work(struct mddev *mddev)
1508{
1509 struct bitmap *bitmap;
1510 unsigned long j;
1511 unsigned long nextpage;
1512 sector_t blocks;
1513 struct bitmap_counts *counts;
1514
1515 /* Use a mutex to guard daemon_work against
1516 * bitmap_destroy.
1517 */
1518 mutex_lock(lock: &mddev->bitmap_info.mutex);
1519 bitmap = mddev->bitmap;
1520 if (bitmap == NULL) {
1521 mutex_unlock(lock: &mddev->bitmap_info.mutex);
1522 return;
1523 }
1524 if (time_before(jiffies, bitmap->daemon_lastrun
1525 + mddev->bitmap_info.daemon_sleep))
1526 goto done;
1527
1528 bitmap->daemon_lastrun = jiffies;
1529 if (bitmap->allclean) {
1530 mddev_set_timeout(mddev, MAX_SCHEDULE_TIMEOUT, force: true);
1531 goto done;
1532 }
1533 bitmap->allclean = 1;
1534
1535 mddev_add_trace_msg(bitmap->mddev, "md bitmap_daemon_work");
1536
1537 /* Any file-page which is PENDING now needs to be written.
1538 * So set NEEDWRITE now, then after we make any last-minute changes
1539 * we will write it.
1540 */
1541 for (j = 0; j < bitmap->storage.file_pages; j++)
1542 if (test_and_clear_page_attr(bitmap, pnum: j,
1543 attr: BITMAP_PAGE_PENDING))
1544 set_page_attr(bitmap, pnum: j,
1545 attr: BITMAP_PAGE_NEEDWRITE);
1546
1547 if (bitmap->need_sync &&
1548 mddev->bitmap_info.external == 0) {
1549 /* Arrange for superblock update as well as
1550 * other changes */
1551 bitmap_super_t *sb;
1552 bitmap->need_sync = 0;
1553 if (bitmap->storage.filemap) {
1554 sb = kmap_local_page(page: bitmap->storage.sb_page);
1555 sb->events_cleared =
1556 cpu_to_le64(bitmap->events_cleared);
1557 kunmap_local(sb);
1558 set_page_attr(bitmap, pnum: 0,
1559 attr: BITMAP_PAGE_NEEDWRITE);
1560 }
1561 }
1562 /* Now look at the bitmap counters and if any are '2' or '1',
1563 * decrement and handle accordingly.
1564 */
1565 counts = &bitmap->counts;
1566 spin_lock_irq(lock: &counts->lock);
1567 nextpage = 0;
1568 for (j = 0; j < counts->chunks; j++) {
1569 bitmap_counter_t *bmc;
1570 sector_t block = (sector_t)j << counts->chunkshift;
1571
1572 if (j == nextpage) {
1573 nextpage += PAGE_COUNTER_RATIO;
1574 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1575 j |= PAGE_COUNTER_MASK;
1576 continue;
1577 }
1578 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1579 }
1580
1581 bmc = md_bitmap_get_counter(bitmap: counts, offset: block, blocks: &blocks, create: 0);
1582 if (!bmc) {
1583 j |= PAGE_COUNTER_MASK;
1584 continue;
1585 }
1586 if (*bmc == 1 && !bitmap->need_sync) {
1587 /* We can clear the bit */
1588 *bmc = 0;
1589 md_bitmap_count_page(bitmap: counts, offset: block, inc: -1);
1590 md_bitmap_file_clear_bit(bitmap, block);
1591 } else if (*bmc && *bmc <= 2) {
1592 *bmc = 1;
1593 md_bitmap_set_pending(bitmap: counts, offset: block);
1594 bitmap->allclean = 0;
1595 }
1596 }
1597 spin_unlock_irq(lock: &counts->lock);
1598
1599 md_bitmap_wait_writes(bitmap);
1600 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1601 * DIRTY pages need to be written by bitmap_unplug so it can wait
1602 * for them.
1603 * If we find any DIRTY page we stop there and let bitmap_unplug
1604 * handle all the rest. This is important in the case where
1605 * the first blocking holds the superblock and it has been updated.
1606 * We mustn't write any other blocks before the superblock.
1607 */
1608 for (j = 0;
1609 j < bitmap->storage.file_pages
1610 && !test_bit(BITMAP_STALE, &bitmap->flags);
1611 j++) {
1612 if (test_page_attr(bitmap, pnum: j,
1613 attr: BITMAP_PAGE_DIRTY))
1614 /* bitmap_unplug will handle the rest */
1615 break;
1616 if (bitmap->storage.filemap &&
1617 test_and_clear_page_attr(bitmap, pnum: j,
1618 attr: BITMAP_PAGE_NEEDWRITE))
1619 filemap_write_page(bitmap, pg_index: j, wait: false);
1620 }
1621
1622 done:
1623 if (bitmap->allclean == 0)
1624 mddev_set_timeout(mddev, timeout: mddev->bitmap_info.daemon_sleep, force: true);
1625 mutex_unlock(lock: &mddev->bitmap_info.mutex);
1626}
1627
1628static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1629 sector_t offset, sector_t *blocks,
1630 int create)
1631__releases(bitmap->lock)
1632__acquires(bitmap->lock)
1633{
1634 /* If 'create', we might release the lock and reclaim it.
1635 * The lock must have been taken with interrupts enabled.
1636 * If !create, we don't release the lock.
1637 */
1638 sector_t chunk = offset >> bitmap->chunkshift;
1639 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1640 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1641 sector_t csize = ((sector_t)1) << bitmap->chunkshift;
1642 int err;
1643
1644 if (page >= bitmap->pages) {
1645 /*
1646 * This can happen if bitmap_start_sync goes beyond
1647 * End-of-device while looking for a whole page or
1648 * user set a huge number to sysfs bitmap_set_bits.
1649 */
1650 *blocks = csize - (offset & (csize - 1));
1651 return NULL;
1652 }
1653 err = md_bitmap_checkpage(bitmap, page, create, no_hijack: 0);
1654
1655 if (bitmap->bp[page].hijacked ||
1656 bitmap->bp[page].map == NULL)
1657 csize = ((sector_t)1) << (bitmap->chunkshift +
1658 PAGE_COUNTER_SHIFT);
1659
1660 *blocks = csize - (offset & (csize - 1));
1661
1662 if (err < 0)
1663 return NULL;
1664
1665 /* now locked ... */
1666
1667 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1668 /* should we use the first or second counter field
1669 * of the hijacked pointer? */
1670 int hi = (pageoff > PAGE_COUNTER_MASK);
1671 return &((bitmap_counter_t *)
1672 &bitmap->bp[page].map)[hi];
1673 } else /* page is allocated */
1674 return (bitmap_counter_t *)
1675 &(bitmap->bp[page].map[pageoff]);
1676}
1677
1678static void bitmap_start_write(struct mddev *mddev, sector_t offset,
1679 unsigned long sectors)
1680{
1681 struct bitmap *bitmap = mddev->bitmap;
1682
1683 if (!bitmap)
1684 return;
1685
1686 while (sectors) {
1687 sector_t blocks;
1688 bitmap_counter_t *bmc;
1689
1690 spin_lock_irq(lock: &bitmap->counts.lock);
1691 bmc = md_bitmap_get_counter(bitmap: &bitmap->counts, offset, blocks: &blocks, create: 1);
1692 if (!bmc) {
1693 spin_unlock_irq(lock: &bitmap->counts.lock);
1694 return;
1695 }
1696
1697 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1698 DEFINE_WAIT(__wait);
1699 /* note that it is safe to do the prepare_to_wait
1700 * after the test as long as we do it before dropping
1701 * the spinlock.
1702 */
1703 prepare_to_wait(wq_head: &bitmap->overflow_wait, wq_entry: &__wait,
1704 TASK_UNINTERRUPTIBLE);
1705 spin_unlock_irq(lock: &bitmap->counts.lock);
1706 schedule();
1707 finish_wait(wq_head: &bitmap->overflow_wait, wq_entry: &__wait);
1708 continue;
1709 }
1710
1711 switch (*bmc) {
1712 case 0:
1713 md_bitmap_file_set_bit(bitmap, block: offset);
1714 md_bitmap_count_page(bitmap: &bitmap->counts, offset, inc: 1);
1715 fallthrough;
1716 case 1:
1717 *bmc = 2;
1718 }
1719
1720 (*bmc)++;
1721
1722 spin_unlock_irq(lock: &bitmap->counts.lock);
1723
1724 offset += blocks;
1725 if (sectors > blocks)
1726 sectors -= blocks;
1727 else
1728 sectors = 0;
1729 }
1730}
1731
1732static void bitmap_end_write(struct mddev *mddev, sector_t offset,
1733 unsigned long sectors)
1734{
1735 struct bitmap *bitmap = mddev->bitmap;
1736
1737 if (!bitmap)
1738 return;
1739
1740 while (sectors) {
1741 sector_t blocks;
1742 unsigned long flags;
1743 bitmap_counter_t *bmc;
1744
1745 spin_lock_irqsave(&bitmap->counts.lock, flags);
1746 bmc = md_bitmap_get_counter(bitmap: &bitmap->counts, offset, blocks: &blocks, create: 0);
1747 if (!bmc) {
1748 spin_unlock_irqrestore(lock: &bitmap->counts.lock, flags);
1749 return;
1750 }
1751
1752 if (!bitmap->mddev->degraded) {
1753 if (bitmap->events_cleared < bitmap->mddev->events) {
1754 bitmap->events_cleared = bitmap->mddev->events;
1755 bitmap->need_sync = 1;
1756 sysfs_notify_dirent_safe(
1757 sd: bitmap->sysfs_can_clear);
1758 }
1759 } else if (!NEEDED(*bmc)) {
1760 *bmc |= NEEDED_MASK;
1761 }
1762
1763 if (COUNTER(*bmc) == COUNTER_MAX)
1764 wake_up(&bitmap->overflow_wait);
1765
1766 (*bmc)--;
1767 if (*bmc <= 2) {
1768 md_bitmap_set_pending(bitmap: &bitmap->counts, offset);
1769 bitmap->allclean = 0;
1770 }
1771 spin_unlock_irqrestore(lock: &bitmap->counts.lock, flags);
1772 offset += blocks;
1773 if (sectors > blocks)
1774 sectors -= blocks;
1775 else
1776 sectors = 0;
1777 }
1778}
1779
1780static bool __bitmap_start_sync(struct bitmap *bitmap, sector_t offset,
1781 sector_t *blocks, bool degraded)
1782{
1783 bitmap_counter_t *bmc;
1784 bool rv = false;
1785
1786 spin_lock_irq(lock: &bitmap->counts.lock);
1787 bmc = md_bitmap_get_counter(bitmap: &bitmap->counts, offset, blocks, create: 0);
1788 if (bmc) {
1789 /* locked */
1790 if (RESYNC(*bmc)) {
1791 rv = true;
1792 } else if (NEEDED(*bmc)) {
1793 rv = true;
1794 if (!degraded) { /* don't set/clear bits if degraded */
1795 *bmc |= RESYNC_MASK;
1796 *bmc &= ~NEEDED_MASK;
1797 }
1798 }
1799 }
1800 spin_unlock_irq(lock: &bitmap->counts.lock);
1801
1802 return rv;
1803}
1804
1805static bool bitmap_start_sync(struct mddev *mddev, sector_t offset,
1806 sector_t *blocks, bool degraded)
1807{
1808 /* bitmap_start_sync must always report on multiples of whole
1809 * pages, otherwise resync (which is very PAGE_SIZE based) will
1810 * get confused.
1811 * So call __bitmap_start_sync repeatedly (if needed) until
1812 * At least PAGE_SIZE>>9 blocks are covered.
1813 * Return the 'or' of the result.
1814 */
1815 bool rv = false;
1816 sector_t blocks1;
1817
1818 *blocks = 0;
1819 while (*blocks < (PAGE_SIZE>>9)) {
1820 rv |= __bitmap_start_sync(bitmap: mddev->bitmap, offset,
1821 blocks: &blocks1, degraded);
1822 offset += blocks1;
1823 *blocks += blocks1;
1824 }
1825
1826 return rv;
1827}
1828
1829static void __bitmap_end_sync(struct bitmap *bitmap, sector_t offset,
1830 sector_t *blocks, bool aborted)
1831{
1832 bitmap_counter_t *bmc;
1833 unsigned long flags;
1834
1835 spin_lock_irqsave(&bitmap->counts.lock, flags);
1836 bmc = md_bitmap_get_counter(bitmap: &bitmap->counts, offset, blocks, create: 0);
1837 if (bmc == NULL)
1838 goto unlock;
1839 /* locked */
1840 if (RESYNC(*bmc)) {
1841 *bmc &= ~RESYNC_MASK;
1842
1843 if (!NEEDED(*bmc) && aborted)
1844 *bmc |= NEEDED_MASK;
1845 else {
1846 if (*bmc <= 2) {
1847 md_bitmap_set_pending(bitmap: &bitmap->counts, offset);
1848 bitmap->allclean = 0;
1849 }
1850 }
1851 }
1852 unlock:
1853 spin_unlock_irqrestore(lock: &bitmap->counts.lock, flags);
1854}
1855
1856static void bitmap_end_sync(struct mddev *mddev, sector_t offset,
1857 sector_t *blocks)
1858{
1859 __bitmap_end_sync(bitmap: mddev->bitmap, offset, blocks, aborted: true);
1860}
1861
1862static void bitmap_close_sync(struct mddev *mddev)
1863{
1864 /* Sync has finished, and any bitmap chunks that weren't synced
1865 * properly have been aborted. It remains to us to clear the
1866 * RESYNC bit wherever it is still on
1867 */
1868 sector_t sector = 0;
1869 sector_t blocks;
1870 struct bitmap *bitmap = mddev->bitmap;
1871
1872 if (!bitmap)
1873 return;
1874
1875 while (sector < bitmap->mddev->resync_max_sectors) {
1876 __bitmap_end_sync(bitmap, offset: sector, blocks: &blocks, aborted: false);
1877 sector += blocks;
1878 }
1879}
1880
1881static void bitmap_cond_end_sync(struct mddev *mddev, sector_t sector,
1882 bool force)
1883{
1884 sector_t s = 0;
1885 sector_t blocks;
1886 struct bitmap *bitmap = mddev->bitmap;
1887
1888 if (!bitmap)
1889 return;
1890 if (sector == 0) {
1891 bitmap->last_end_sync = jiffies;
1892 return;
1893 }
1894 if (!force && time_before(jiffies, (bitmap->last_end_sync
1895 + bitmap->mddev->bitmap_info.daemon_sleep)))
1896 return;
1897 wait_event(bitmap->mddev->recovery_wait,
1898 atomic_read(&bitmap->mddev->recovery_active) == 0);
1899
1900 bitmap->mddev->curr_resync_completed = sector;
1901 set_bit(nr: MD_SB_CHANGE_CLEAN, addr: &bitmap->mddev->sb_flags);
1902 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1903 s = 0;
1904 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1905 __bitmap_end_sync(bitmap, offset: s, blocks: &blocks, aborted: false);
1906 s += blocks;
1907 }
1908 bitmap->last_end_sync = jiffies;
1909 sysfs_notify_dirent_safe(sd: bitmap->mddev->sysfs_completed);
1910}
1911
1912static void bitmap_sync_with_cluster(struct mddev *mddev,
1913 sector_t old_lo, sector_t old_hi,
1914 sector_t new_lo, sector_t new_hi)
1915{
1916 struct bitmap *bitmap = mddev->bitmap;
1917 sector_t sector, blocks = 0;
1918
1919 for (sector = old_lo; sector < new_lo; ) {
1920 __bitmap_end_sync(bitmap, offset: sector, blocks: &blocks, aborted: false);
1921 sector += blocks;
1922 }
1923 WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
1924
1925 for (sector = old_hi; sector < new_hi; ) {
1926 bitmap_start_sync(mddev, offset: sector, blocks: &blocks, degraded: false);
1927 sector += blocks;
1928 }
1929 WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
1930}
1931
1932static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1933{
1934 /* For each chunk covered by any of these sectors, set the
1935 * counter to 2 and possibly set resync_needed. They should all
1936 * be 0 at this point
1937 */
1938
1939 sector_t secs;
1940 bitmap_counter_t *bmc;
1941 spin_lock_irq(lock: &bitmap->counts.lock);
1942 bmc = md_bitmap_get_counter(bitmap: &bitmap->counts, offset, blocks: &secs, create: 1);
1943 if (!bmc) {
1944 spin_unlock_irq(lock: &bitmap->counts.lock);
1945 return;
1946 }
1947 if (!*bmc) {
1948 *bmc = 2;
1949 md_bitmap_count_page(bitmap: &bitmap->counts, offset, inc: 1);
1950 md_bitmap_set_pending(bitmap: &bitmap->counts, offset);
1951 bitmap->allclean = 0;
1952 }
1953 if (needed)
1954 *bmc |= NEEDED_MASK;
1955 spin_unlock_irq(lock: &bitmap->counts.lock);
1956}
1957
1958/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1959static void bitmap_dirty_bits(struct mddev *mddev, unsigned long s,
1960 unsigned long e)
1961{
1962 unsigned long chunk;
1963 struct bitmap *bitmap = mddev->bitmap;
1964
1965 if (!bitmap)
1966 return;
1967
1968 for (chunk = s; chunk <= e; chunk++) {
1969 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1970
1971 md_bitmap_set_memory_bits(bitmap, offset: sec, needed: 1);
1972 md_bitmap_file_set_bit(bitmap, block: sec);
1973 if (sec < bitmap->mddev->resync_offset)
1974 /* We are asserting that the array is dirty,
1975 * so move the resync_offset address back so
1976 * that it is obvious that it is dirty
1977 */
1978 bitmap->mddev->resync_offset = sec;
1979 }
1980}
1981
1982static void bitmap_flush(struct mddev *mddev)
1983{
1984 struct bitmap *bitmap = mddev->bitmap;
1985 long sleep;
1986
1987 if (!bitmap) /* there was no bitmap */
1988 return;
1989
1990 /* run the daemon_work three time to ensure everything is flushed
1991 * that can be
1992 */
1993 sleep = mddev->bitmap_info.daemon_sleep * 2;
1994 bitmap->daemon_lastrun -= sleep;
1995 bitmap_daemon_work(mddev);
1996 bitmap->daemon_lastrun -= sleep;
1997 bitmap_daemon_work(mddev);
1998 bitmap->daemon_lastrun -= sleep;
1999 bitmap_daemon_work(mddev);
2000 if (mddev->bitmap_info.external)
2001 md_super_wait(mddev);
2002 bitmap_update_sb(data: bitmap);
2003}
2004
2005static void md_bitmap_free(void *data)
2006{
2007 unsigned long k, pages;
2008 struct bitmap_page *bp;
2009 struct bitmap *bitmap = data;
2010
2011 if (!bitmap) /* there was no bitmap */
2012 return;
2013
2014 if (bitmap->sysfs_can_clear)
2015 sysfs_put(kn: bitmap->sysfs_can_clear);
2016
2017 if (mddev_is_clustered(mddev: bitmap->mddev) && bitmap->mddev->cluster_info &&
2018 bitmap->cluster_slot == bitmap->mddev->cluster_ops->slot_number(bitmap->mddev))
2019 md_cluster_stop(mddev: bitmap->mddev);
2020
2021 /* Shouldn't be needed - but just in case.... */
2022 wait_event(bitmap->write_wait,
2023 atomic_read(&bitmap->pending_writes) == 0);
2024
2025 /* release the bitmap file */
2026 md_bitmap_file_unmap(store: &bitmap->storage);
2027
2028 bp = bitmap->counts.bp;
2029 pages = bitmap->counts.pages;
2030
2031 /* free all allocated memory */
2032
2033 if (bp) /* deallocate the page memory */
2034 for (k = 0; k < pages; k++)
2035 if (bp[k].map && !bp[k].hijacked)
2036 kfree(objp: bp[k].map);
2037 kfree(objp: bp);
2038 kfree(objp: bitmap);
2039}
2040
2041static void bitmap_start_behind_write(struct mddev *mddev)
2042{
2043 struct bitmap *bitmap = mddev->bitmap;
2044 int bw;
2045
2046 atomic_inc(v: &bitmap->behind_writes);
2047 bw = atomic_read(v: &bitmap->behind_writes);
2048 if (bw > bitmap->behind_writes_used)
2049 bitmap->behind_writes_used = bw;
2050
2051 pr_debug("inc write-behind count %d/%lu\n",
2052 bw, bitmap->mddev->bitmap_info.max_write_behind);
2053}
2054
2055static void bitmap_end_behind_write(struct mddev *mddev)
2056{
2057 struct bitmap *bitmap = mddev->bitmap;
2058
2059 if (atomic_dec_and_test(v: &bitmap->behind_writes))
2060 wake_up(&bitmap->behind_wait);
2061 pr_debug("dec write-behind count %d/%lu\n",
2062 atomic_read(&bitmap->behind_writes),
2063 bitmap->mddev->bitmap_info.max_write_behind);
2064}
2065
2066static void bitmap_wait_behind_writes(struct mddev *mddev)
2067{
2068 struct bitmap *bitmap = mddev->bitmap;
2069
2070 /* wait for behind writes to complete */
2071 if (bitmap && atomic_read(v: &bitmap->behind_writes) > 0) {
2072 pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
2073 mdname(mddev));
2074 /* need to kick something here to make sure I/O goes? */
2075 wait_event(bitmap->behind_wait,
2076 atomic_read(&bitmap->behind_writes) == 0);
2077 }
2078}
2079
2080static void bitmap_destroy(struct mddev *mddev)
2081{
2082 struct bitmap *bitmap = mddev->bitmap;
2083
2084 if (!bitmap) /* there was no bitmap */
2085 return;
2086
2087 bitmap_wait_behind_writes(mddev);
2088 if (!mddev->serialize_policy)
2089 mddev_destroy_serial_pool(mddev, NULL);
2090
2091 mutex_lock(lock: &mddev->bitmap_info.mutex);
2092 spin_lock(lock: &mddev->lock);
2093 mddev->bitmap = NULL; /* disconnect from the md device */
2094 spin_unlock(lock: &mddev->lock);
2095 mutex_unlock(lock: &mddev->bitmap_info.mutex);
2096 mddev_set_timeout(mddev, MAX_SCHEDULE_TIMEOUT, force: true);
2097
2098 md_bitmap_free(data: bitmap);
2099}
2100
2101/*
2102 * initialize the bitmap structure
2103 * if this returns an error, bitmap_destroy must be called to do clean up
2104 * once mddev->bitmap is set
2105 */
2106static struct bitmap *__bitmap_create(struct mddev *mddev, int slot)
2107{
2108 struct bitmap *bitmap;
2109 sector_t blocks = mddev->resync_max_sectors;
2110 struct file *file = mddev->bitmap_info.file;
2111 int err;
2112 struct kernfs_node *bm = NULL;
2113
2114 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
2115
2116 BUG_ON(file && mddev->bitmap_info.offset);
2117
2118 if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
2119 pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
2120 mdname(mddev));
2121 return ERR_PTR(error: -EBUSY);
2122 }
2123
2124 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
2125 if (!bitmap)
2126 return ERR_PTR(error: -ENOMEM);
2127
2128 spin_lock_init(&bitmap->counts.lock);
2129 atomic_set(v: &bitmap->pending_writes, i: 0);
2130 init_waitqueue_head(&bitmap->write_wait);
2131 init_waitqueue_head(&bitmap->overflow_wait);
2132 init_waitqueue_head(&bitmap->behind_wait);
2133
2134 bitmap->mddev = mddev;
2135 bitmap->cluster_slot = slot;
2136
2137 if (mddev->kobj.sd)
2138 bm = sysfs_get_dirent(parent: mddev->kobj.sd, name: "bitmap");
2139 if (bm) {
2140 bitmap->sysfs_can_clear = sysfs_get_dirent(parent: bm, name: "can_clear");
2141 sysfs_put(kn: bm);
2142 } else
2143 bitmap->sysfs_can_clear = NULL;
2144
2145 bitmap->storage.file = file;
2146 if (file) {
2147 get_file(f: file);
2148 /* As future accesses to this file will use bmap,
2149 * and bypass the page cache, we must sync the file
2150 * first.
2151 */
2152 vfs_fsync(file, datasync: 1);
2153 }
2154 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
2155 if (!mddev->bitmap_info.external) {
2156 /*
2157 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
2158 * instructing us to create a new on-disk bitmap instance.
2159 */
2160 if (test_and_clear_bit(nr: MD_ARRAY_FIRST_USE, addr: &mddev->flags))
2161 err = md_bitmap_new_disk_sb(bitmap);
2162 else
2163 err = md_bitmap_read_sb(bitmap);
2164 } else {
2165 err = 0;
2166 if (mddev->bitmap_info.chunksize == 0 ||
2167 mddev->bitmap_info.daemon_sleep == 0)
2168 /* chunksize and time_base need to be
2169 * set first. */
2170 err = -EINVAL;
2171 }
2172 if (err)
2173 goto error;
2174
2175 bitmap->daemon_lastrun = jiffies;
2176 err = __bitmap_resize(bitmap, blocks, chunksize: mddev->bitmap_info.chunksize,
2177 init: true);
2178 if (err)
2179 goto error;
2180
2181 pr_debug("created bitmap (%lu pages) for device %s\n",
2182 bitmap->counts.pages, bmname(bitmap));
2183
2184 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
2185 if (err)
2186 goto error;
2187
2188 return bitmap;
2189 error:
2190 md_bitmap_free(data: bitmap);
2191 return ERR_PTR(error: err);
2192}
2193
2194static int bitmap_create(struct mddev *mddev)
2195{
2196 struct bitmap *bitmap = __bitmap_create(mddev, slot: -1);
2197
2198 if (IS_ERR(ptr: bitmap))
2199 return PTR_ERR(ptr: bitmap);
2200
2201 mddev->bitmap = bitmap;
2202 return 0;
2203}
2204
2205static int bitmap_load(struct mddev *mddev)
2206{
2207 int err = 0;
2208 sector_t start = 0;
2209 sector_t sector = 0;
2210 struct bitmap *bitmap = mddev->bitmap;
2211 struct md_rdev *rdev;
2212
2213 if (!bitmap)
2214 goto out;
2215
2216 rdev_for_each(rdev, mddev)
2217 mddev_create_serial_pool(mddev, rdev);
2218
2219 if (mddev_is_clustered(mddev))
2220 mddev->cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
2221
2222 /* Clear out old bitmap info first: Either there is none, or we
2223 * are resuming after someone else has possibly changed things,
2224 * so we should forget old cached info.
2225 * All chunks should be clean, but some might need_sync.
2226 */
2227 while (sector < mddev->resync_max_sectors) {
2228 sector_t blocks;
2229 bitmap_start_sync(mddev, offset: sector, blocks: &blocks, degraded: false);
2230 sector += blocks;
2231 }
2232 bitmap_close_sync(mddev);
2233
2234 if (mddev->degraded == 0
2235 || bitmap->events_cleared == mddev->events)
2236 /* no need to keep dirty bits to optimise a
2237 * re-add of a missing device */
2238 start = mddev->resync_offset;
2239
2240 mutex_lock(lock: &mddev->bitmap_info.mutex);
2241 err = md_bitmap_init_from_disk(bitmap, start);
2242 mutex_unlock(lock: &mddev->bitmap_info.mutex);
2243
2244 if (err)
2245 goto out;
2246 clear_bit(nr: BITMAP_STALE, addr: &bitmap->flags);
2247
2248 /* Kick recovery in case any bits were set */
2249 set_bit(nr: MD_RECOVERY_NEEDED, addr: &bitmap->mddev->recovery);
2250
2251 mddev_set_timeout(mddev, timeout: mddev->bitmap_info.daemon_sleep, force: true);
2252 md_wakeup_thread(thread: mddev->thread);
2253
2254 bitmap_update_sb(data: bitmap);
2255
2256 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
2257 err = -EIO;
2258out:
2259 return err;
2260}
2261
2262/* caller need to free returned bitmap with md_bitmap_free() */
2263static void *bitmap_get_from_slot(struct mddev *mddev, int slot)
2264{
2265 int rv = 0;
2266 struct bitmap *bitmap;
2267
2268 bitmap = __bitmap_create(mddev, slot);
2269 if (IS_ERR(ptr: bitmap)) {
2270 rv = PTR_ERR(ptr: bitmap);
2271 return ERR_PTR(error: rv);
2272 }
2273
2274 rv = md_bitmap_init_from_disk(bitmap, start: 0);
2275 if (rv) {
2276 md_bitmap_free(data: bitmap);
2277 return ERR_PTR(error: rv);
2278 }
2279
2280 return bitmap;
2281}
2282
2283/* Loads the bitmap associated with slot and copies the resync information
2284 * to our bitmap
2285 */
2286static int bitmap_copy_from_slot(struct mddev *mddev, int slot, sector_t *low,
2287 sector_t *high, bool clear_bits)
2288{
2289 int rv = 0, i, j;
2290 sector_t block, lo = 0, hi = 0;
2291 struct bitmap_counts *counts;
2292 struct bitmap *bitmap;
2293
2294 bitmap = bitmap_get_from_slot(mddev, slot);
2295 if (IS_ERR(ptr: bitmap)) {
2296 pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
2297 return -1;
2298 }
2299
2300 counts = &bitmap->counts;
2301 for (j = 0; j < counts->chunks; j++) {
2302 block = (sector_t)j << counts->chunkshift;
2303 if (md_bitmap_file_test_bit(bitmap, block)) {
2304 if (!lo)
2305 lo = block;
2306 hi = block;
2307 md_bitmap_file_clear_bit(bitmap, block);
2308 md_bitmap_set_memory_bits(bitmap: mddev->bitmap, offset: block, needed: 1);
2309 md_bitmap_file_set_bit(bitmap: mddev->bitmap, block);
2310 }
2311 }
2312
2313 if (clear_bits) {
2314 bitmap_update_sb(data: bitmap);
2315 /* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
2316 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
2317 for (i = 0; i < bitmap->storage.file_pages; i++)
2318 if (test_page_attr(bitmap, pnum: i, attr: BITMAP_PAGE_PENDING))
2319 set_page_attr(bitmap, pnum: i, attr: BITMAP_PAGE_NEEDWRITE);
2320 __bitmap_unplug(bitmap);
2321 }
2322 __bitmap_unplug(bitmap: mddev->bitmap);
2323 *low = lo;
2324 *high = hi;
2325 md_bitmap_free(data: bitmap);
2326
2327 return rv;
2328}
2329
2330static void bitmap_set_pages(void *data, unsigned long pages)
2331{
2332 struct bitmap *bitmap = data;
2333
2334 bitmap->counts.pages = pages;
2335}
2336
2337static int bitmap_get_stats(void *data, struct md_bitmap_stats *stats)
2338{
2339 struct bitmap_storage *storage;
2340 struct bitmap_counts *counts;
2341 struct bitmap *bitmap = data;
2342 bitmap_super_t *sb;
2343
2344 if (!bitmap)
2345 return -ENOENT;
2346 if (!bitmap->storage.sb_page)
2347 return -EINVAL;
2348 sb = kmap_local_page(page: bitmap->storage.sb_page);
2349 stats->sync_size = le64_to_cpu(sb->sync_size);
2350 kunmap_local(sb);
2351
2352 counts = &bitmap->counts;
2353 stats->missing_pages = counts->missing_pages;
2354 stats->pages = counts->pages;
2355
2356 storage = &bitmap->storage;
2357 stats->file_pages = storage->file_pages;
2358 stats->file = storage->file;
2359
2360 stats->behind_writes = atomic_read(v: &bitmap->behind_writes);
2361 stats->behind_wait = wq_has_sleeper(wq_head: &bitmap->behind_wait);
2362 stats->events_cleared = bitmap->events_cleared;
2363 return 0;
2364}
2365
2366static int __bitmap_resize(struct bitmap *bitmap, sector_t blocks,
2367 int chunksize, bool init)
2368{
2369 /* If chunk_size is 0, choose an appropriate chunk size.
2370 * Then possibly allocate new storage space.
2371 * Then quiesce, copy bits, replace bitmap, and re-start
2372 *
2373 * This function is called both to set up the initial bitmap
2374 * and to resize the bitmap while the array is active.
2375 * If this happens as a result of the array being resized,
2376 * chunksize will be zero, and we need to choose a suitable
2377 * chunksize, otherwise we use what we are given.
2378 */
2379 struct bitmap_storage store;
2380 struct bitmap_counts old_counts;
2381 unsigned long chunks;
2382 sector_t block;
2383 sector_t old_blocks, new_blocks;
2384 int chunkshift;
2385 int ret = 0;
2386 long pages;
2387 struct bitmap_page *new_bp;
2388
2389 if (bitmap->storage.file && !init) {
2390 pr_info("md: cannot resize file-based bitmap\n");
2391 return -EINVAL;
2392 }
2393
2394 if (chunksize == 0) {
2395 /* If there is enough space, leave the chunk size unchanged,
2396 * else increase by factor of two until there is enough space.
2397 */
2398 long bytes;
2399 long space = bitmap->mddev->bitmap_info.space;
2400
2401 if (space == 0) {
2402 /* We don't know how much space there is, so limit
2403 * to current size - in sectors.
2404 */
2405 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
2406 if (!bitmap->mddev->bitmap_info.external)
2407 bytes += sizeof(bitmap_super_t);
2408 space = DIV_ROUND_UP(bytes, 512);
2409 bitmap->mddev->bitmap_info.space = space;
2410 }
2411 chunkshift = bitmap->counts.chunkshift;
2412 chunkshift--;
2413 do {
2414 /* 'chunkshift' is shift from block size to chunk size */
2415 chunkshift++;
2416 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2417 bytes = DIV_ROUND_UP(chunks, 8);
2418 if (!bitmap->mddev->bitmap_info.external)
2419 bytes += sizeof(bitmap_super_t);
2420 } while (bytes > (space << 9) && (chunkshift + BITMAP_BLOCK_SHIFT) <
2421 (BITS_PER_BYTE * sizeof(((bitmap_super_t *)0)->chunksize) - 1));
2422 } else
2423 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
2424
2425 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2426 memset(s: &store, c: 0, n: sizeof(store));
2427 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2428 ret = md_bitmap_storage_alloc(store: &store, chunks,
2429 with_super: !bitmap->mddev->bitmap_info.external,
2430 slot_number: mddev_is_clustered(mddev: bitmap->mddev)
2431 ? bitmap->cluster_slot : 0);
2432 if (ret) {
2433 md_bitmap_file_unmap(store: &store);
2434 goto err;
2435 }
2436
2437 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2438
2439 new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
2440 ret = -ENOMEM;
2441 if (!new_bp) {
2442 md_bitmap_file_unmap(store: &store);
2443 goto err;
2444 }
2445
2446 if (!init)
2447 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2448
2449 store.file = bitmap->storage.file;
2450 bitmap->storage.file = NULL;
2451
2452 if (store.sb_page && bitmap->storage.sb_page)
2453 memcpy(page_address(store.sb_page),
2454 page_address(bitmap->storage.sb_page),
2455 len: sizeof(bitmap_super_t));
2456 spin_lock_irq(lock: &bitmap->counts.lock);
2457 md_bitmap_file_unmap(store: &bitmap->storage);
2458 bitmap->storage = store;
2459
2460 old_counts = bitmap->counts;
2461 bitmap->counts.bp = new_bp;
2462 bitmap->counts.pages = pages;
2463 bitmap->counts.missing_pages = pages;
2464 bitmap->counts.chunkshift = chunkshift;
2465 bitmap->counts.chunks = chunks;
2466 bitmap->mddev->bitmap_info.chunksize = 1UL << (chunkshift +
2467 BITMAP_BLOCK_SHIFT);
2468
2469 blocks = min(old_counts.chunks << old_counts.chunkshift,
2470 chunks << chunkshift);
2471
2472 /* For cluster raid, need to pre-allocate bitmap */
2473 if (mddev_is_clustered(mddev: bitmap->mddev)) {
2474 unsigned long page;
2475 for (page = 0; page < pages; page++) {
2476 ret = md_bitmap_checkpage(bitmap: &bitmap->counts, page, create: 1, no_hijack: 1);
2477 if (ret) {
2478 unsigned long k;
2479
2480 /* deallocate the page memory */
2481 for (k = 0; k < page; k++) {
2482 kfree(objp: new_bp[k].map);
2483 }
2484 kfree(objp: new_bp);
2485
2486 /* restore some fields from old_counts */
2487 bitmap->counts.bp = old_counts.bp;
2488 bitmap->counts.pages = old_counts.pages;
2489 bitmap->counts.missing_pages = old_counts.pages;
2490 bitmap->counts.chunkshift = old_counts.chunkshift;
2491 bitmap->counts.chunks = old_counts.chunks;
2492 bitmap->mddev->bitmap_info.chunksize =
2493 1UL << (old_counts.chunkshift + BITMAP_BLOCK_SHIFT);
2494 blocks = old_counts.chunks << old_counts.chunkshift;
2495 pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
2496 break;
2497 } else
2498 bitmap->counts.bp[page].count += 1;
2499 }
2500 }
2501
2502 for (block = 0; block < blocks; ) {
2503 bitmap_counter_t *bmc_old, *bmc_new;
2504 int set;
2505
2506 bmc_old = md_bitmap_get_counter(bitmap: &old_counts, offset: block, blocks: &old_blocks, create: 0);
2507 set = bmc_old && NEEDED(*bmc_old);
2508
2509 if (set) {
2510 bmc_new = md_bitmap_get_counter(bitmap: &bitmap->counts, offset: block, blocks: &new_blocks, create: 1);
2511 if (bmc_new) {
2512 if (*bmc_new == 0) {
2513 /* need to set on-disk bits too. */
2514 sector_t end = block + new_blocks;
2515 sector_t start = block >> chunkshift;
2516
2517 start <<= chunkshift;
2518 while (start < end) {
2519 md_bitmap_file_set_bit(bitmap, block);
2520 start += 1 << chunkshift;
2521 }
2522 *bmc_new = 2;
2523 md_bitmap_count_page(bitmap: &bitmap->counts, offset: block, inc: 1);
2524 md_bitmap_set_pending(bitmap: &bitmap->counts, offset: block);
2525 }
2526 *bmc_new |= NEEDED_MASK;
2527 }
2528 if (new_blocks < old_blocks)
2529 old_blocks = new_blocks;
2530 }
2531 block += old_blocks;
2532 }
2533
2534 if (bitmap->counts.bp != old_counts.bp) {
2535 unsigned long k;
2536 for (k = 0; k < old_counts.pages; k++)
2537 if (!old_counts.bp[k].hijacked)
2538 kfree(objp: old_counts.bp[k].map);
2539 kfree(objp: old_counts.bp);
2540 }
2541
2542 if (!init) {
2543 int i;
2544 while (block < (chunks << chunkshift)) {
2545 bitmap_counter_t *bmc;
2546 bmc = md_bitmap_get_counter(bitmap: &bitmap->counts, offset: block, blocks: &new_blocks, create: 1);
2547 if (bmc) {
2548 /* new space. It needs to be resynced, so
2549 * we set NEEDED_MASK.
2550 */
2551 if (*bmc == 0) {
2552 *bmc = NEEDED_MASK | 2;
2553 md_bitmap_count_page(bitmap: &bitmap->counts, offset: block, inc: 1);
2554 md_bitmap_set_pending(bitmap: &bitmap->counts, offset: block);
2555 }
2556 }
2557 block += new_blocks;
2558 }
2559 for (i = 0; i < bitmap->storage.file_pages; i++)
2560 set_page_attr(bitmap, pnum: i, attr: BITMAP_PAGE_DIRTY);
2561 }
2562 spin_unlock_irq(lock: &bitmap->counts.lock);
2563
2564 if (!init) {
2565 __bitmap_unplug(bitmap);
2566 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2567 }
2568 ret = 0;
2569err:
2570 return ret;
2571}
2572
2573static int bitmap_resize(struct mddev *mddev, sector_t blocks, int chunksize)
2574{
2575 struct bitmap *bitmap = mddev->bitmap;
2576
2577 if (!bitmap)
2578 return 0;
2579
2580 return __bitmap_resize(bitmap, blocks, chunksize, init: false);
2581}
2582
2583static ssize_t
2584location_show(struct mddev *mddev, char *page)
2585{
2586 ssize_t len;
2587 if (mddev->bitmap_info.file)
2588 len = sprintf(buf: page, fmt: "file");
2589 else if (mddev->bitmap_info.offset)
2590 len = sprintf(buf: page, fmt: "%+lld", (long long)mddev->bitmap_info.offset);
2591 else
2592 len = sprintf(buf: page, fmt: "none");
2593 len += sprintf(buf: page+len, fmt: "\n");
2594 return len;
2595}
2596
2597static ssize_t
2598location_store(struct mddev *mddev, const char *buf, size_t len)
2599{
2600 int rv;
2601
2602 rv = mddev_suspend_and_lock(mddev);
2603 if (rv)
2604 return rv;
2605
2606 if (mddev->pers) {
2607 if (mddev->recovery || mddev->sync_thread) {
2608 rv = -EBUSY;
2609 goto out;
2610 }
2611 }
2612
2613 if (mddev->bitmap || mddev->bitmap_info.file ||
2614 mddev->bitmap_info.offset) {
2615 /* bitmap already configured. Only option is to clear it */
2616 if (strncmp(buf, "none", 4) != 0) {
2617 rv = -EBUSY;
2618 goto out;
2619 }
2620
2621 bitmap_destroy(mddev);
2622 mddev->bitmap_info.offset = 0;
2623 if (mddev->bitmap_info.file) {
2624 struct file *f = mddev->bitmap_info.file;
2625 mddev->bitmap_info.file = NULL;
2626 fput(f);
2627 }
2628 } else {
2629 /* No bitmap, OK to set a location */
2630 long long offset;
2631
2632 if (strncmp(buf, "none", 4) == 0)
2633 /* nothing to be done */;
2634 else if (strncmp(buf, "file:", 5) == 0) {
2635 /* Not supported yet */
2636 rv = -EINVAL;
2637 goto out;
2638 } else {
2639 if (buf[0] == '+')
2640 rv = kstrtoll(s: buf+1, base: 10, res: &offset);
2641 else
2642 rv = kstrtoll(s: buf, base: 10, res: &offset);
2643 if (rv)
2644 goto out;
2645 if (offset == 0) {
2646 rv = -EINVAL;
2647 goto out;
2648 }
2649 if (mddev->bitmap_info.external == 0 &&
2650 mddev->major_version == 0 &&
2651 offset != mddev->bitmap_info.default_offset) {
2652 rv = -EINVAL;
2653 goto out;
2654 }
2655
2656 mddev->bitmap_info.offset = offset;
2657 rv = bitmap_create(mddev);
2658 if (rv)
2659 goto out;
2660
2661 rv = bitmap_load(mddev);
2662 if (rv) {
2663 mddev->bitmap_info.offset = 0;
2664 bitmap_destroy(mddev);
2665 goto out;
2666 }
2667 }
2668 }
2669 if (!mddev->external) {
2670 /* Ensure new bitmap info is stored in
2671 * metadata promptly.
2672 */
2673 set_bit(nr: MD_SB_CHANGE_DEVS, addr: &mddev->sb_flags);
2674 md_wakeup_thread(thread: mddev->thread);
2675 }
2676 rv = 0;
2677out:
2678 mddev_unlock_and_resume(mddev);
2679 if (rv)
2680 return rv;
2681 return len;
2682}
2683
2684static struct md_sysfs_entry bitmap_location =
2685__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2686
2687/* 'bitmap/space' is the space available at 'location' for the
2688 * bitmap. This allows the kernel to know when it is safe to
2689 * resize the bitmap to match a resized array.
2690 */
2691static ssize_t
2692space_show(struct mddev *mddev, char *page)
2693{
2694 return sprintf(buf: page, fmt: "%lu\n", mddev->bitmap_info.space);
2695}
2696
2697static ssize_t
2698space_store(struct mddev *mddev, const char *buf, size_t len)
2699{
2700 struct bitmap *bitmap;
2701 unsigned long sectors;
2702 int rv;
2703
2704 rv = kstrtoul(s: buf, base: 10, res: &sectors);
2705 if (rv)
2706 return rv;
2707
2708 if (sectors == 0)
2709 return -EINVAL;
2710
2711 bitmap = mddev->bitmap;
2712 if (bitmap && sectors < (bitmap->storage.bytes + 511) >> 9)
2713 return -EFBIG; /* Bitmap is too big for this small space */
2714
2715 /* could make sure it isn't too big, but that isn't really
2716 * needed - user-space should be careful.
2717 */
2718 mddev->bitmap_info.space = sectors;
2719 return len;
2720}
2721
2722static struct md_sysfs_entry bitmap_space =
2723__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2724
2725static ssize_t
2726timeout_show(struct mddev *mddev, char *page)
2727{
2728 ssize_t len;
2729 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2730 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2731
2732 len = sprintf(buf: page, fmt: "%lu", secs);
2733 if (jifs)
2734 len += sprintf(buf: page+len, fmt: ".%03u", jiffies_to_msecs(j: jifs));
2735 len += sprintf(buf: page+len, fmt: "\n");
2736 return len;
2737}
2738
2739static ssize_t
2740timeout_store(struct mddev *mddev, const char *buf, size_t len)
2741{
2742 /* timeout can be set at any time */
2743 unsigned long timeout;
2744 int rv = strict_strtoul_scaled(cp: buf, res: &timeout, scale: 4);
2745 if (rv)
2746 return rv;
2747
2748 /* just to make sure we don't overflow... */
2749 if (timeout >= LONG_MAX / HZ)
2750 return -EINVAL;
2751
2752 timeout = timeout * HZ / 10000;
2753
2754 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2755 timeout = MAX_SCHEDULE_TIMEOUT-1;
2756 if (timeout < 1)
2757 timeout = 1;
2758
2759 mddev->bitmap_info.daemon_sleep = timeout;
2760 mddev_set_timeout(mddev, timeout, force: false);
2761 md_wakeup_thread(thread: mddev->thread);
2762
2763 return len;
2764}
2765
2766static struct md_sysfs_entry bitmap_timeout =
2767__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2768
2769static ssize_t
2770backlog_show(struct mddev *mddev, char *page)
2771{
2772 return sprintf(buf: page, fmt: "%lu\n", mddev->bitmap_info.max_write_behind);
2773}
2774
2775static ssize_t
2776backlog_store(struct mddev *mddev, const char *buf, size_t len)
2777{
2778 unsigned long backlog;
2779 unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
2780 struct md_rdev *rdev;
2781 bool has_write_mostly = false;
2782 int rv = kstrtoul(s: buf, base: 10, res: &backlog);
2783 if (rv)
2784 return rv;
2785 if (backlog > COUNTER_MAX)
2786 return -EINVAL;
2787
2788 rv = mddev_suspend_and_lock(mddev);
2789 if (rv)
2790 return rv;
2791
2792 /*
2793 * Without write mostly device, it doesn't make sense to set
2794 * backlog for max_write_behind.
2795 */
2796 rdev_for_each(rdev, mddev) {
2797 if (test_bit(WriteMostly, &rdev->flags)) {
2798 has_write_mostly = true;
2799 break;
2800 }
2801 }
2802 if (!has_write_mostly) {
2803 pr_warn_ratelimited("%s: can't set backlog, no write mostly device available\n",
2804 mdname(mddev));
2805 mddev_unlock(mddev);
2806 return -EINVAL;
2807 }
2808
2809 mddev->bitmap_info.max_write_behind = backlog;
2810 if (!backlog && mddev->serial_info_pool) {
2811 /* serial_info_pool is not needed if backlog is zero */
2812 if (!mddev->serialize_policy)
2813 mddev_destroy_serial_pool(mddev, NULL);
2814 } else if (backlog && !mddev->serial_info_pool) {
2815 /* serial_info_pool is needed since backlog is not zero */
2816 rdev_for_each(rdev, mddev)
2817 mddev_create_serial_pool(mddev, rdev);
2818 }
2819 if (old_mwb != backlog)
2820 bitmap_update_sb(data: mddev->bitmap);
2821
2822 mddev_unlock_and_resume(mddev);
2823 return len;
2824}
2825
2826static struct md_sysfs_entry bitmap_backlog =
2827__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2828
2829static ssize_t
2830chunksize_show(struct mddev *mddev, char *page)
2831{
2832 return sprintf(buf: page, fmt: "%lu\n", mddev->bitmap_info.chunksize);
2833}
2834
2835static ssize_t
2836chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2837{
2838 /* Can only be changed when no bitmap is active */
2839 int rv;
2840 unsigned long csize;
2841 if (mddev->bitmap)
2842 return -EBUSY;
2843 rv = kstrtoul(s: buf, base: 10, res: &csize);
2844 if (rv)
2845 return rv;
2846 if (csize < 512 ||
2847 !is_power_of_2(n: csize))
2848 return -EINVAL;
2849 if (BITS_PER_LONG > 32 && csize >= (1ULL << (BITS_PER_BYTE *
2850 sizeof(((bitmap_super_t *)0)->chunksize))))
2851 return -EOVERFLOW;
2852 mddev->bitmap_info.chunksize = csize;
2853 return len;
2854}
2855
2856static struct md_sysfs_entry bitmap_chunksize =
2857__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2858
2859static ssize_t metadata_show(struct mddev *mddev, char *page)
2860{
2861 if (mddev_is_clustered(mddev))
2862 return sprintf(buf: page, fmt: "clustered\n");
2863 return sprintf(buf: page, fmt: "%s\n", (mddev->bitmap_info.external
2864 ? "external" : "internal"));
2865}
2866
2867static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2868{
2869 if (mddev->bitmap ||
2870 mddev->bitmap_info.file ||
2871 mddev->bitmap_info.offset)
2872 return -EBUSY;
2873 if (strncmp(buf, "external", 8) == 0)
2874 mddev->bitmap_info.external = 1;
2875 else if ((strncmp(buf, "internal", 8) == 0) ||
2876 (strncmp(buf, "clustered", 9) == 0))
2877 mddev->bitmap_info.external = 0;
2878 else
2879 return -EINVAL;
2880 return len;
2881}
2882
2883static struct md_sysfs_entry bitmap_metadata =
2884__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2885
2886static ssize_t can_clear_show(struct mddev *mddev, char *page)
2887{
2888 int len;
2889 struct bitmap *bitmap;
2890
2891 spin_lock(lock: &mddev->lock);
2892 bitmap = mddev->bitmap;
2893 if (bitmap)
2894 len = sprintf(buf: page, fmt: "%s\n", (bitmap->need_sync ? "false" :
2895 "true"));
2896 else
2897 len = sprintf(buf: page, fmt: "\n");
2898 spin_unlock(lock: &mddev->lock);
2899 return len;
2900}
2901
2902static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2903{
2904 struct bitmap *bitmap = mddev->bitmap;
2905
2906 if (!bitmap)
2907 return -ENOENT;
2908
2909 if (strncmp(buf, "false", 5) == 0) {
2910 bitmap->need_sync = 1;
2911 return len;
2912 }
2913
2914 if (strncmp(buf, "true", 4) == 0) {
2915 if (mddev->degraded)
2916 return -EBUSY;
2917 bitmap->need_sync = 0;
2918 return len;
2919 }
2920
2921 return -EINVAL;
2922}
2923
2924static struct md_sysfs_entry bitmap_can_clear =
2925__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2926
2927static ssize_t
2928behind_writes_used_show(struct mddev *mddev, char *page)
2929{
2930 ssize_t ret;
2931 struct bitmap *bitmap;
2932
2933 spin_lock(lock: &mddev->lock);
2934 bitmap = mddev->bitmap;
2935 if (!bitmap)
2936 ret = sprintf(buf: page, fmt: "0\n");
2937 else
2938 ret = sprintf(buf: page, fmt: "%lu\n", bitmap->behind_writes_used);
2939 spin_unlock(lock: &mddev->lock);
2940
2941 return ret;
2942}
2943
2944static ssize_t
2945behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2946{
2947 struct bitmap *bitmap = mddev->bitmap;
2948
2949 if (bitmap)
2950 bitmap->behind_writes_used = 0;
2951 return len;
2952}
2953
2954static struct md_sysfs_entry max_backlog_used =
2955__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2956 behind_writes_used_show, behind_writes_used_reset);
2957
2958static struct attribute *md_bitmap_attrs[] = {
2959 &bitmap_location.attr,
2960 &bitmap_space.attr,
2961 &bitmap_timeout.attr,
2962 &bitmap_backlog.attr,
2963 &bitmap_chunksize.attr,
2964 &bitmap_metadata.attr,
2965 &bitmap_can_clear.attr,
2966 &max_backlog_used.attr,
2967 NULL
2968};
2969
2970static struct attribute_group md_bitmap_group = {
2971 .name = "bitmap",
2972 .attrs = md_bitmap_attrs,
2973};
2974
2975static struct bitmap_operations bitmap_ops = {
2976 .head = {
2977 .type = MD_BITMAP,
2978 .id = ID_BITMAP,
2979 .name = "bitmap",
2980 },
2981
2982 .enabled = bitmap_enabled,
2983 .create = bitmap_create,
2984 .resize = bitmap_resize,
2985 .load = bitmap_load,
2986 .destroy = bitmap_destroy,
2987 .flush = bitmap_flush,
2988 .write_all = bitmap_write_all,
2989 .dirty_bits = bitmap_dirty_bits,
2990 .unplug = bitmap_unplug,
2991 .daemon_work = bitmap_daemon_work,
2992
2993 .start_behind_write = bitmap_start_behind_write,
2994 .end_behind_write = bitmap_end_behind_write,
2995 .wait_behind_writes = bitmap_wait_behind_writes,
2996
2997 .start_write = bitmap_start_write,
2998 .end_write = bitmap_end_write,
2999 .start_discard = bitmap_start_write,
3000 .end_discard = bitmap_end_write,
3001
3002 .start_sync = bitmap_start_sync,
3003 .end_sync = bitmap_end_sync,
3004 .cond_end_sync = bitmap_cond_end_sync,
3005 .close_sync = bitmap_close_sync,
3006
3007 .update_sb = bitmap_update_sb,
3008 .get_stats = bitmap_get_stats,
3009
3010 .sync_with_cluster = bitmap_sync_with_cluster,
3011 .get_from_slot = bitmap_get_from_slot,
3012 .copy_from_slot = bitmap_copy_from_slot,
3013 .set_pages = bitmap_set_pages,
3014 .free = md_bitmap_free,
3015
3016 .group = &md_bitmap_group,
3017};
3018
3019int md_bitmap_init(void)
3020{
3021 md_bitmap_wq = alloc_workqueue("md_bitmap", WQ_MEM_RECLAIM | WQ_UNBOUND,
3022 0);
3023 if (!md_bitmap_wq)
3024 return -ENOMEM;
3025
3026 return register_md_submodule(msh: &bitmap_ops.head);
3027}
3028
3029void md_bitmap_exit(void)
3030{
3031 destroy_workqueue(wq: md_bitmap_wq);
3032 unregister_md_submodule(msh: &bitmap_ops.head);
3033}
3034