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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
4 *
5 * bitmap_create - sets up the bitmap structure
6 * bitmap_destroy - destroys the bitmap structure
7 *
8 * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
9 * - added disk storage for bitmap
10 * - changes to allow various bitmap chunk sizes
11 */
12
13/*
14 * Still to do:
15 *
16 * flush after percent set rather than just time based. (maybe both).
17 */
18
19#include <linux/blkdev.h>
20#include <linux/module.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/init.h>
24#include <linux/timer.h>
25#include <linux/sched.h>
26#include <linux/list.h>
27#include <linux/file.h>
28#include <linux/mount.h>
29#include <linux/buffer_head.h>
30#include <linux/seq_file.h>
31#include <trace/events/block.h>
32#include "md.h"
33#include "md-bitmap.h"
34
35#define BITMAP_MAJOR_LO 3
36/* version 4 insists the bitmap is in little-endian order
37 * with version 3, it is host-endian which is non-portable
38 * Version 5 is currently set only for clustered devices
39 */
40#define BITMAP_MAJOR_HI 4
41#define BITMAP_MAJOR_CLUSTERED 5
42#define BITMAP_MAJOR_HOSTENDIAN 3
43
44/*
45 * in-memory bitmap:
46 *
47 * Use 16 bit block counters to track pending writes to each "chunk".
48 * The 2 high order bits are special-purpose, the first is a flag indicating
49 * whether a resync is needed. The second is a flag indicating whether a
50 * resync is active.
51 * This means that the counter is actually 14 bits:
52 *
53 * +--------+--------+------------------------------------------------+
54 * | resync | resync | counter |
55 * | needed | active | |
56 * | (0-1) | (0-1) | (0-16383) |
57 * +--------+--------+------------------------------------------------+
58 *
59 * The "resync needed" bit is set when:
60 * a '1' bit is read from storage at startup.
61 * a write request fails on some drives
62 * a resync is aborted on a chunk with 'resync active' set
63 * It is cleared (and resync-active set) when a resync starts across all drives
64 * of the chunk.
65 *
66 *
67 * The "resync active" bit is set when:
68 * a resync is started on all drives, and resync_needed is set.
69 * resync_needed will be cleared (as long as resync_active wasn't already set).
70 * It is cleared when a resync completes.
71 *
72 * The counter counts pending write requests, plus the on-disk bit.
73 * When the counter is '1' and the resync bits are clear, the on-disk
74 * bit can be cleared as well, thus setting the counter to 0.
75 * When we set a bit, or in the counter (to start a write), if the fields is
76 * 0, we first set the disk bit and set the counter to 1.
77 *
78 * If the counter is 0, the on-disk bit is clear and the stripe is clean
79 * Anything that dirties the stripe pushes the counter to 2 (at least)
80 * and sets the on-disk bit (lazily).
81 * If a periodic sweep find the counter at 2, it is decremented to 1.
82 * If the sweep find the counter at 1, the on-disk bit is cleared and the
83 * counter goes to zero.
84 *
85 * Also, we'll hijack the "map" pointer itself and use it as two 16 bit block
86 * counters as a fallback when "page" memory cannot be allocated:
87 *
88 * Normal case (page memory allocated):
89 *
90 * page pointer (32-bit)
91 *
92 * [ ] ------+
93 * |
94 * +-------> [ ][ ]..[ ] (4096 byte page == 2048 counters)
95 * c1 c2 c2048
96 *
97 * Hijacked case (page memory allocation failed):
98 *
99 * hijacked page pointer (32-bit)
100 *
101 * [ ][ ] (no page memory allocated)
102 * counter #1 (16-bit) counter #2 (16-bit)
103 *
104 */
105
106#define PAGE_BITS (PAGE_SIZE << 3)
107#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3)
108
109#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
110#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK)
111#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX)
112
113/* how many counters per page? */
114#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS)
115/* same, except a shift value for more efficient bitops */
116#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT)
117/* same, except a mask value for more efficient bitops */
118#define PAGE_COUNTER_MASK (PAGE_COUNTER_RATIO - 1)
119
120#define BITMAP_BLOCK_SHIFT 9
121
122/*
123 * bitmap structures:
124 */
125
126/* the in-memory bitmap is represented by bitmap_pages */
127struct bitmap_page {
128 /*
129 * map points to the actual memory page
130 */
131 char *map;
132 /*
133 * in emergencies (when map cannot be alloced), hijack the map
134 * pointer and use it as two counters itself
135 */
136 unsigned int hijacked:1;
137 /*
138 * If any counter in this page is '1' or '2' - and so could be
139 * cleared then that page is marked as 'pending'
140 */
141 unsigned int pending:1;
142 /*
143 * count of dirty bits on the page
144 */
145 unsigned int count:30;
146};
147
148/* the main bitmap structure - one per mddev */
149struct bitmap {
150
151 struct bitmap_counts {
152 spinlock_t lock;
153 struct bitmap_page *bp;
154 /* total number of pages in the bitmap */
155 unsigned long pages;
156 /* number of pages not yet allocated */
157 unsigned long missing_pages;
158 /* chunksize = 2^chunkshift (for bitops) */
159 unsigned long chunkshift;
160 /* total number of data chunks for the array */
161 unsigned long chunks;
162 } counts;
163
164 struct mddev *mddev; /* the md device that the bitmap is for */
165
166 __u64 events_cleared;
167 int need_sync;
168
169 struct bitmap_storage {
170 /* backing disk file */
171 struct file *file;
172 /* cached copy of the bitmap file superblock */
173 struct page *sb_page;
174 unsigned long sb_index;
175 /* list of cache pages for the file */
176 struct page **filemap;
177 /* attributes associated filemap pages */
178 unsigned long *filemap_attr;
179 /* number of pages in the file */
180 unsigned long file_pages;
181 /* total bytes in the bitmap */
182 unsigned long bytes;
183 } storage;
184
185 unsigned long flags;
186
187 int allclean;
188
189 atomic_t behind_writes;
190 /* highest actual value at runtime */
191 unsigned long behind_writes_used;
192
193 /*
194 * the bitmap daemon - periodically wakes up and sweeps the bitmap
195 * file, cleaning up bits and flushing out pages to disk as necessary
196 */
197 unsigned long daemon_lastrun; /* jiffies of last run */
198 /*
199 * when we lasted called end_sync to update bitmap with resync
200 * progress.
201 */
202 unsigned long last_end_sync;
203
204 /* pending writes to the bitmap file */
205 atomic_t pending_writes;
206 wait_queue_head_t write_wait;
207 wait_queue_head_t overflow_wait;
208 wait_queue_head_t behind_wait;
209
210 struct kernfs_node *sysfs_can_clear;
211 /* slot offset for clustered env */
212 int cluster_slot;
213};
214
215static int __bitmap_resize(struct bitmap *bitmap, sector_t blocks,
216 int chunksize, bool init);
217
218static inline char *bmname(struct bitmap *bitmap)
219{
220 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
221}
222
223static bool __bitmap_enabled(struct bitmap *bitmap)
224{
225 return bitmap->storage.filemap &&
226 !test_bit(BITMAP_STALE, &bitmap->flags);
227}
228
229static bool bitmap_enabled(struct mddev *mddev)
230{
231 struct bitmap *bitmap = mddev->bitmap;
232
233 if (!bitmap)
234 return false;
235
236 return __bitmap_enabled(bitmap);
237}
238
239/*
240 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
241 *
242 * 1) check to see if this page is allocated, if it's not then try to alloc
243 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
244 * page pointer directly as a counter
245 *
246 * if we find our page, we increment the page's refcount so that it stays
247 * allocated while we're using it
248 */
249static int md_bitmap_checkpage(struct bitmap_counts *bitmap,
250 unsigned long page, int create, int no_hijack)
251__releases(bitmap->lock)
252__acquires(bitmap->lock)
253{
254 unsigned char *mappage;
255
256 WARN_ON_ONCE(page >= bitmap->pages);
257 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
258 return 0;
259
260 if (bitmap->bp[page].map) /* page is already allocated, just return */
261 return 0;
262
263 if (!create)
264 return -ENOENT;
265
266 /* this page has not been allocated yet */
267
268 spin_unlock_irq(&bitmap->lock);
269 /* It is possible that this is being called inside a
270 * prepare_to_wait/finish_wait loop from raid5c:make_request().
271 * In general it is not permitted to sleep in that context as it
272 * can cause the loop to spin freely.
273 * That doesn't apply here as we can only reach this point
274 * once with any loop.
275 * When this function completes, either bp[page].map or
276 * bp[page].hijacked. In either case, this function will
277 * abort before getting to this point again. So there is
278 * no risk of a free-spin, and so it is safe to assert
279 * that sleeping here is allowed.
280 */
281 sched_annotate_sleep();
282 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
283 spin_lock_irq(&bitmap->lock);
284
285 if (mappage == NULL) {
286 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
287 /* We don't support hijack for cluster raid */
288 if (no_hijack)
289 return -ENOMEM;
290 /* failed - set the hijacked flag so that we can use the
291 * pointer as a counter */
292 if (!bitmap->bp[page].map)
293 bitmap->bp[page].hijacked = 1;
294 } else if (bitmap->bp[page].map ||
295 bitmap->bp[page].hijacked) {
296 /* somebody beat us to getting the page */
297 kfree(mappage);
298 } else {
299
300 /* no page was in place and we have one, so install it */
301
302 bitmap->bp[page].map = mappage;
303 bitmap->missing_pages--;
304 }
305 return 0;
306}
307
308/* if page is completely empty, put it back on the free list, or dealloc it */
309/* if page was hijacked, unmark the flag so it might get alloced next time */
310/* Note: lock should be held when calling this */
311static void md_bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
312{
313 char *ptr;
314
315 if (bitmap->bp[page].count) /* page is still busy */
316 return;
317
318 /* page is no longer in use, it can be released */
319
320 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
321 bitmap->bp[page].hijacked = 0;
322 bitmap->bp[page].map = NULL;
323 } else {
324 /* normal case, free the page */
325 ptr = bitmap->bp[page].map;
326 bitmap->bp[page].map = NULL;
327 bitmap->missing_pages++;
328 kfree(ptr);
329 }
330}
331
332/*
333 * bitmap file handling - read and write the bitmap file and its superblock
334 */
335
336/*
337 * basic page I/O operations
338 */
339
340/* IO operations when bitmap is stored near all superblocks */
341
342/* choose a good rdev and read the page from there */
343static int read_sb_page(struct mddev *mddev, loff_t offset,
344 struct page *page, unsigned long index, int size)
345{
346
347 sector_t sector = mddev->bitmap_info.offset + offset +
348 index * (PAGE_SIZE / SECTOR_SIZE);
349 struct md_rdev *rdev;
350
351 rdev_for_each(rdev, mddev) {
352 u32 iosize = roundup(size, bdev_logical_block_size(rdev->bdev));
353
354 if (!test_bit(In_sync, &rdev->flags) ||
355 test_bit(Faulty, &rdev->flags) ||
356 test_bit(Bitmap_sync, &rdev->flags))
357 continue;
358
359 if (sync_page_io(rdev, sector, iosize, page, REQ_OP_READ, true))
360 return 0;
361 }
362 return -EIO;
363}
364
365static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
366{
367 /* Iterate the disks of an mddev, using rcu to protect access to the
368 * linked list, and raising the refcount of devices we return to ensure
369 * they don't disappear while in use.
370 * As devices are only added or removed when raid_disk is < 0 and
371 * nr_pending is 0 and In_sync is clear, the entries we return will
372 * still be in the same position on the list when we re-enter
373 * list_for_each_entry_continue_rcu.
374 *
375 * Note that if entered with 'rdev == NULL' to start at the
376 * beginning, we temporarily assign 'rdev' to an address which
377 * isn't really an rdev, but which can be used by
378 * list_for_each_entry_continue_rcu() to find the first entry.
379 */
380 rcu_read_lock();
381 if (rdev == NULL)
382 /* start at the beginning */
383 rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
384 else {
385 /* release the previous rdev and start from there. */
386 rdev_dec_pending(rdev, mddev);
387 }
388 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
389 if (rdev->raid_disk >= 0 &&
390 !test_bit(Faulty, &rdev->flags)) {
391 /* this is a usable devices */
392 atomic_inc(&rdev->nr_pending);
393 rcu_read_unlock();
394 return rdev;
395 }
396 }
397 rcu_read_unlock();
398 return NULL;
399}
400
401static unsigned int optimal_io_size(struct block_device *bdev,
402 unsigned int last_page_size,
403 unsigned int io_size)
404{
405 if (bdev_io_opt(bdev) > bdev_logical_block_size(bdev))
406 return roundup(last_page_size, bdev_io_opt(bdev));
407 return io_size;
408}
409
410static unsigned int bitmap_io_size(unsigned int io_size, unsigned int opt_size,
411 loff_t start, loff_t boundary)
412{
413 if (io_size != opt_size &&
414 start + opt_size / SECTOR_SIZE <= boundary)
415 return opt_size;
416 if (start + io_size / SECTOR_SIZE <= boundary)
417 return io_size;
418
419 /* Overflows boundary */
420 return 0;
421}
422
423static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
424 unsigned long pg_index, struct page *page)
425{
426 struct block_device *bdev;
427 struct mddev *mddev = bitmap->mddev;
428 struct bitmap_storage *store = &bitmap->storage;
429 unsigned int bitmap_limit = (bitmap->storage.file_pages - pg_index) <<
430 PAGE_SHIFT;
431 loff_t sboff, offset = mddev->bitmap_info.offset;
432 sector_t ps = pg_index * PAGE_SIZE / SECTOR_SIZE;
433 unsigned int size = PAGE_SIZE;
434 unsigned int opt_size = PAGE_SIZE;
435 sector_t doff;
436
437 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
438 /* we compare length (page numbers), not page offset. */
439 if ((pg_index - store->sb_index) == store->file_pages - 1) {
440 unsigned int last_page_size = store->bytes & (PAGE_SIZE - 1);
441
442 if (last_page_size == 0)
443 last_page_size = PAGE_SIZE;
444 size = roundup(last_page_size, bdev_logical_block_size(bdev));
445 opt_size = optimal_io_size(bdev, last_page_size, size);
446 }
447
448 sboff = rdev->sb_start + offset;
449 doff = rdev->data_offset;
450
451 /* Just make sure we aren't corrupting data or metadata */
452 if (mddev->external) {
453 /* Bitmap could be anywhere. */
454 if (sboff + ps > doff &&
455 sboff < (doff + mddev->dev_sectors + PAGE_SIZE / SECTOR_SIZE))
456 return -EINVAL;
457 } else if (offset < 0) {
458 /* DATA BITMAP METADATA */
459 size = bitmap_io_size(size, opt_size, offset + ps, 0);
460 if (size == 0)
461 /* bitmap runs in to metadata */
462 return -EINVAL;
463
464 if (doff + mddev->dev_sectors > sboff)
465 /* data runs in to bitmap */
466 return -EINVAL;
467 } else if (rdev->sb_start < rdev->data_offset) {
468 /* METADATA BITMAP DATA */
469 size = bitmap_io_size(size, opt_size, sboff + ps, doff);
470 if (size == 0)
471 /* bitmap runs in to data */
472 return -EINVAL;
473 }
474
475 md_super_write(mddev, rdev, sboff + ps, (int)min(size, bitmap_limit), page);
476 return 0;
477}
478
479static void write_sb_page(struct bitmap *bitmap, unsigned long pg_index,
480 struct page *page, bool wait)
481{
482 struct mddev *mddev = bitmap->mddev;
483
484 do {
485 struct md_rdev *rdev = NULL;
486
487 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
488 if (__write_sb_page(rdev, bitmap, pg_index, page) < 0) {
489 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
490 return;
491 }
492 }
493 } while (wait && md_super_wait(mddev) < 0);
494}
495
496static void md_bitmap_file_kick(struct bitmap *bitmap);
497
498#ifdef CONFIG_MD_BITMAP_FILE
499static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
500{
501 struct buffer_head *bh = page_buffers(page);
502
503 while (bh && bh->b_blocknr) {
504 atomic_inc(&bitmap->pending_writes);
505 set_buffer_locked(bh);
506 set_buffer_mapped(bh);
507 submit_bh(REQ_OP_WRITE | REQ_SYNC, bh);
508 bh = bh->b_this_page;
509 }
510
511 if (wait)
512 wait_event(bitmap->write_wait,
513 atomic_read(&bitmap->pending_writes) == 0);
514}
515
516static void end_bitmap_write(struct buffer_head *bh, int uptodate)
517{
518 struct bitmap *bitmap = bh->b_private;
519
520 if (!uptodate)
521 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
522 if (atomic_dec_and_test(&bitmap->pending_writes))
523 wake_up(&bitmap->write_wait);
524}
525
526static void free_buffers(struct page *page)
527{
528 struct buffer_head *bh;
529
530 if (!PagePrivate(page))
531 return;
532
533 bh = page_buffers(page);
534 while (bh) {
535 struct buffer_head *next = bh->b_this_page;
536 free_buffer_head(bh);
537 bh = next;
538 }
539 detach_page_private(page);
540 put_page(page);
541}
542
543/* read a page from a file.
544 * We both read the page, and attach buffers to the page to record the
545 * address of each block (using bmap). These addresses will be used
546 * to write the block later, completely bypassing the filesystem.
547 * This usage is similar to how swap files are handled, and allows us
548 * to write to a file with no concerns of memory allocation failing.
549 */
550static int read_file_page(struct file *file, unsigned long index,
551 struct bitmap *bitmap, unsigned long count, struct page *page)
552{
553 int ret = 0;
554 struct inode *inode = file_inode(file);
555 struct buffer_head *bh;
556 sector_t block, blk_cur;
557 unsigned long blocksize = i_blocksize(inode);
558
559 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
560 (unsigned long long)index << PAGE_SHIFT);
561
562 bh = alloc_page_buffers(page, blocksize);
563 if (!bh) {
564 ret = -ENOMEM;
565 goto out;
566 }
567 attach_page_private(page, bh);
568 blk_cur = index << (PAGE_SHIFT - inode->i_blkbits);
569 while (bh) {
570 block = blk_cur;
571
572 if (count == 0)
573 bh->b_blocknr = 0;
574 else {
575 ret = bmap(inode, &block);
576 if (ret || !block) {
577 ret = -EINVAL;
578 bh->b_blocknr = 0;
579 goto out;
580 }
581
582 bh->b_blocknr = block;
583 bh->b_bdev = inode->i_sb->s_bdev;
584 if (count < blocksize)
585 count = 0;
586 else
587 count -= blocksize;
588
589 bh->b_end_io = end_bitmap_write;
590 bh->b_private = bitmap;
591 atomic_inc(&bitmap->pending_writes);
592 set_buffer_locked(bh);
593 set_buffer_mapped(bh);
594 submit_bh(REQ_OP_READ, bh);
595 }
596 blk_cur++;
597 bh = bh->b_this_page;
598 }
599
600 wait_event(bitmap->write_wait,
601 atomic_read(&bitmap->pending_writes)==0);
602 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
603 ret = -EIO;
604out:
605 if (ret)
606 pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
607 (int)PAGE_SIZE,
608 (unsigned long long)index << PAGE_SHIFT,
609 ret);
610 return ret;
611}
612#else /* CONFIG_MD_BITMAP_FILE */
613static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
614{
615}
616static int read_file_page(struct file *file, unsigned long index,
617 struct bitmap *bitmap, unsigned long count, struct page *page)
618{
619 return -EIO;
620}
621static void free_buffers(struct page *page)
622{
623 put_page(page);
624}
625#endif /* CONFIG_MD_BITMAP_FILE */
626
627/*
628 * bitmap file superblock operations
629 */
630
631/*
632 * write out a page to a file
633 */
634static void filemap_write_page(struct bitmap *bitmap, unsigned long pg_index,
635 bool wait)
636{
637 struct bitmap_storage *store = &bitmap->storage;
638 struct page *page = store->filemap[pg_index];
639
640 if (mddev_is_clustered(bitmap->mddev)) {
641 /* go to node bitmap area starting point */
642 pg_index += store->sb_index;
643 }
644
645 if (store->file)
646 write_file_page(bitmap, page, wait);
647 else
648 write_sb_page(bitmap, pg_index, page, wait);
649}
650
651/*
652 * md_bitmap_wait_writes() should be called before writing any bitmap
653 * blocks, to ensure previous writes, particularly from
654 * md_bitmap_daemon_work(), have completed.
655 */
656static void md_bitmap_wait_writes(struct bitmap *bitmap)
657{
658 if (bitmap->storage.file)
659 wait_event(bitmap->write_wait,
660 atomic_read(&bitmap->pending_writes)==0);
661 else
662 /* Note that we ignore the return value. The writes
663 * might have failed, but that would just mean that
664 * some bits which should be cleared haven't been,
665 * which is safe. The relevant bitmap blocks will
666 * probably get written again, but there is no great
667 * loss if they aren't.
668 */
669 md_super_wait(bitmap->mddev);
670}
671
672
673/* update the event counter and sync the superblock to disk */
674static void bitmap_update_sb(void *data)
675{
676 bitmap_super_t *sb;
677 struct bitmap *bitmap = data;
678
679 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
680 return;
681 if (bitmap->mddev->bitmap_info.external)
682 return;
683 if (!bitmap->storage.sb_page) /* no superblock */
684 return;
685 sb = kmap_atomic(bitmap->storage.sb_page);
686 sb->events = cpu_to_le64(bitmap->mddev->events);
687 if (bitmap->mddev->events < bitmap->events_cleared)
688 /* rocking back to read-only */
689 bitmap->events_cleared = bitmap->mddev->events;
690 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
691 /*
692 * clear BITMAP_WRITE_ERROR bit to protect against the case that
693 * a bitmap write error occurred but the later writes succeeded.
694 */
695 sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR));
696 /* Just in case these have been changed via sysfs: */
697 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
698 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
699 /* This might have been changed by a reshape */
700 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
701 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
702 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
703 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
704 bitmap_info.space);
705 kunmap_atomic(sb);
706
707 if (bitmap->storage.file)
708 write_file_page(bitmap, bitmap->storage.sb_page, 1);
709 else
710 write_sb_page(bitmap, bitmap->storage.sb_index,
711 bitmap->storage.sb_page, 1);
712}
713
714static void bitmap_print_sb(struct bitmap *bitmap)
715{
716 bitmap_super_t *sb;
717
718 if (!bitmap || !bitmap->storage.sb_page)
719 return;
720 sb = kmap_atomic(bitmap->storage.sb_page);
721 pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
722 pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic));
723 pr_debug(" version: %u\n", le32_to_cpu(sb->version));
724 pr_debug(" uuid: %08x.%08x.%08x.%08x\n",
725 le32_to_cpu(*(__le32 *)(sb->uuid+0)),
726 le32_to_cpu(*(__le32 *)(sb->uuid+4)),
727 le32_to_cpu(*(__le32 *)(sb->uuid+8)),
728 le32_to_cpu(*(__le32 *)(sb->uuid+12)));
729 pr_debug(" events: %llu\n",
730 (unsigned long long) le64_to_cpu(sb->events));
731 pr_debug("events cleared: %llu\n",
732 (unsigned long long) le64_to_cpu(sb->events_cleared));
733 pr_debug(" state: %08x\n", le32_to_cpu(sb->state));
734 pr_debug(" chunksize: %u B\n", le32_to_cpu(sb->chunksize));
735 pr_debug(" daemon sleep: %us\n", le32_to_cpu(sb->daemon_sleep));
736 pr_debug(" sync size: %llu KB\n",
737 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
738 pr_debug("max write behind: %u\n", le32_to_cpu(sb->write_behind));
739 kunmap_atomic(sb);
740}
741
742/*
743 * bitmap_new_disk_sb
744 * @bitmap
745 *
746 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
747 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
748 * This function verifies 'bitmap_info' and populates the on-disk bitmap
749 * structure, which is to be written to disk.
750 *
751 * Returns: 0 on success, -Exxx on error
752 */
753static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
754{
755 bitmap_super_t *sb;
756 unsigned long chunksize, daemon_sleep, write_behind;
757
758 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
759 if (bitmap->storage.sb_page == NULL)
760 return -ENOMEM;
761 bitmap->storage.sb_index = 0;
762
763 sb = kmap_atomic(bitmap->storage.sb_page);
764
765 sb->magic = cpu_to_le32(BITMAP_MAGIC);
766 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
767
768 chunksize = bitmap->mddev->bitmap_info.chunksize;
769 BUG_ON(!chunksize);
770 if (!is_power_of_2(chunksize)) {
771 kunmap_atomic(sb);
772 pr_warn("bitmap chunksize not a power of 2\n");
773 return -EINVAL;
774 }
775 sb->chunksize = cpu_to_le32(chunksize);
776
777 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
778 if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
779 pr_debug("Choosing daemon_sleep default (5 sec)\n");
780 daemon_sleep = 5 * HZ;
781 }
782 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
783 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
784
785 /*
786 * FIXME: write_behind for RAID1. If not specified, what
787 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
788 */
789 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
790 if (write_behind > COUNTER_MAX)
791 write_behind = COUNTER_MAX / 2;
792 sb->write_behind = cpu_to_le32(write_behind);
793 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
794
795 /* keep the array size field of the bitmap superblock up to date */
796 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
797
798 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
799
800 set_bit(BITMAP_STALE, &bitmap->flags);
801 sb->state = cpu_to_le32(bitmap->flags);
802 bitmap->events_cleared = bitmap->mddev->events;
803 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
804 bitmap->mddev->bitmap_info.nodes = 0;
805
806 kunmap_atomic(sb);
807
808 return 0;
809}
810
811/* read the superblock from the bitmap file and initialize some bitmap fields */
812static int md_bitmap_read_sb(struct bitmap *bitmap)
813{
814 char *reason = NULL;
815 bitmap_super_t *sb;
816 unsigned long chunksize, daemon_sleep, write_behind;
817 unsigned long long events;
818 int nodes = 0;
819 unsigned long sectors_reserved = 0;
820 int err = -EINVAL;
821 struct page *sb_page;
822 loff_t offset = 0;
823
824 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
825 chunksize = 128 * 1024 * 1024;
826 daemon_sleep = 5 * HZ;
827 write_behind = 0;
828 set_bit(BITMAP_STALE, &bitmap->flags);
829 err = 0;
830 goto out_no_sb;
831 }
832 /* page 0 is the superblock, read it... */
833 sb_page = alloc_page(GFP_KERNEL);
834 if (!sb_page)
835 return -ENOMEM;
836 bitmap->storage.sb_page = sb_page;
837
838re_read:
839 /* If cluster_slot is set, the cluster is setup */
840 if (bitmap->cluster_slot >= 0) {
841 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
842
843 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks,
844 (bitmap->mddev->bitmap_info.chunksize >> 9));
845 /* bits to bytes */
846 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
847 /* to 4k blocks */
848 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
849 offset = bitmap->cluster_slot * (bm_blocks << 3);
850 pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
851 bitmap->cluster_slot, offset);
852 }
853
854 if (bitmap->storage.file) {
855 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
856 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
857
858 err = read_file_page(bitmap->storage.file, 0,
859 bitmap, bytes, sb_page);
860 } else {
861 err = read_sb_page(bitmap->mddev, offset, sb_page, 0,
862 sizeof(bitmap_super_t));
863 }
864 if (err)
865 return err;
866
867 err = -EINVAL;
868 sb = kmap_atomic(sb_page);
869
870 chunksize = le32_to_cpu(sb->chunksize);
871 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
872 write_behind = le32_to_cpu(sb->write_behind);
873 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
874
875 /* verify that the bitmap-specific fields are valid */
876 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
877 reason = "bad magic";
878 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
879 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
880 reason = "unrecognized superblock version";
881 else if (chunksize < 512)
882 reason = "bitmap chunksize too small";
883 else if (!is_power_of_2(chunksize))
884 reason = "bitmap chunksize not a power of 2";
885 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
886 reason = "daemon sleep period out of range";
887 else if (write_behind > COUNTER_MAX)
888 reason = "write-behind limit out of range (0 - 16383)";
889 if (reason) {
890 pr_warn("%s: invalid bitmap file superblock: %s\n",
891 bmname(bitmap), reason);
892 goto out;
893 }
894
895 /*
896 * Setup nodes/clustername only if bitmap version is
897 * cluster-compatible
898 */
899 if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
900 nodes = le32_to_cpu(sb->nodes);
901 strscpy(bitmap->mddev->bitmap_info.cluster_name,
902 sb->cluster_name, 64);
903 }
904
905 /* keep the array size field of the bitmap superblock up to date */
906 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
907
908 if (bitmap->mddev->persistent) {
909 /*
910 * We have a persistent array superblock, so compare the
911 * bitmap's UUID and event counter to the mddev's
912 */
913 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
914 pr_warn("%s: bitmap superblock UUID mismatch\n",
915 bmname(bitmap));
916 goto out;
917 }
918 events = le64_to_cpu(sb->events);
919 if (!nodes && (events < bitmap->mddev->events)) {
920 pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
921 bmname(bitmap), events,
922 (unsigned long long) bitmap->mddev->events);
923 set_bit(BITMAP_STALE, &bitmap->flags);
924 }
925 }
926
927 /* assign fields using values from superblock */
928 bitmap->flags |= le32_to_cpu(sb->state);
929 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
930 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
931 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
932 err = 0;
933
934out:
935 kunmap_atomic(sb);
936 if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
937 /* Assigning chunksize is required for "re_read" */
938 bitmap->mddev->bitmap_info.chunksize = chunksize;
939 err = md_setup_cluster(bitmap->mddev, nodes);
940 if (err) {
941 pr_warn("%s: Could not setup cluster service (%d)\n",
942 bmname(bitmap), err);
943 goto out_no_sb;
944 }
945 bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
946 goto re_read;
947 }
948
949out_no_sb:
950 if (err == 0) {
951 if (test_bit(BITMAP_STALE, &bitmap->flags))
952 bitmap->events_cleared = bitmap->mddev->events;
953 bitmap->mddev->bitmap_info.chunksize = chunksize;
954 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
955 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
956 bitmap->mddev->bitmap_info.nodes = nodes;
957 if (bitmap->mddev->bitmap_info.space == 0 ||
958 bitmap->mddev->bitmap_info.space > sectors_reserved)
959 bitmap->mddev->bitmap_info.space = sectors_reserved;
960 } else {
961 bitmap_print_sb(bitmap);
962 if (bitmap->cluster_slot < 0)
963 md_cluster_stop(bitmap->mddev);
964 }
965 return err;
966}
967
968/*
969 * general bitmap file operations
970 */
971
972/*
973 * on-disk bitmap:
974 *
975 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
976 * file a page at a time. There's a superblock at the start of the file.
977 */
978/* calculate the index of the page that contains this bit */
979static inline unsigned long file_page_index(struct bitmap_storage *store,
980 unsigned long chunk)
981{
982 if (store->sb_page)
983 chunk += sizeof(bitmap_super_t) << 3;
984 return chunk >> PAGE_BIT_SHIFT;
985}
986
987/* calculate the (bit) offset of this bit within a page */
988static inline unsigned long file_page_offset(struct bitmap_storage *store,
989 unsigned long chunk)
990{
991 if (store->sb_page)
992 chunk += sizeof(bitmap_super_t) << 3;
993 return chunk & (PAGE_BITS - 1);
994}
995
996/*
997 * return a pointer to the page in the filemap that contains the given bit
998 *
999 */
1000static inline struct page *filemap_get_page(struct bitmap_storage *store,
1001 unsigned long chunk)
1002{
1003 if (file_page_index(store, chunk) >= store->file_pages)
1004 return NULL;
1005 return store->filemap[file_page_index(store, chunk)];
1006}
1007
1008static int md_bitmap_storage_alloc(struct bitmap_storage *store,
1009 unsigned long chunks, int with_super,
1010 int slot_number)
1011{
1012 int pnum, offset = 0;
1013 unsigned long num_pages;
1014 unsigned long bytes;
1015
1016 bytes = DIV_ROUND_UP(chunks, 8);
1017 if (with_super)
1018 bytes += sizeof(bitmap_super_t);
1019
1020 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
1021 offset = slot_number * num_pages;
1022
1023 store->filemap = kmalloc_array(num_pages, sizeof(struct page *),
1024 GFP_KERNEL);
1025 if (!store->filemap)
1026 return -ENOMEM;
1027
1028 if (with_super && !store->sb_page) {
1029 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
1030 if (store->sb_page == NULL)
1031 return -ENOMEM;
1032 }
1033
1034 pnum = 0;
1035 if (store->sb_page) {
1036 store->filemap[0] = store->sb_page;
1037 pnum = 1;
1038 store->sb_index = offset;
1039 }
1040
1041 for ( ; pnum < num_pages; pnum++) {
1042 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
1043 if (!store->filemap[pnum]) {
1044 store->file_pages = pnum;
1045 return -ENOMEM;
1046 }
1047 }
1048 store->file_pages = pnum;
1049
1050 /* We need 4 bits per page, rounded up to a multiple
1051 * of sizeof(unsigned long) */
1052 store->filemap_attr = kzalloc(
1053 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
1054 GFP_KERNEL);
1055 if (!store->filemap_attr)
1056 return -ENOMEM;
1057
1058 store->bytes = bytes;
1059
1060 return 0;
1061}
1062
1063static void md_bitmap_file_unmap(struct bitmap_storage *store)
1064{
1065 struct file *file = store->file;
1066 struct page *sb_page = store->sb_page;
1067 struct page **map = store->filemap;
1068 int pages = store->file_pages;
1069
1070 while (pages--)
1071 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
1072 free_buffers(map[pages]);
1073 kfree(map);
1074 kfree(store->filemap_attr);
1075
1076 if (sb_page)
1077 free_buffers(sb_page);
1078
1079 if (file) {
1080 struct inode *inode = file_inode(file);
1081 invalidate_mapping_pages(inode->i_mapping, 0, -1);
1082 fput(file);
1083 }
1084}
1085
1086/*
1087 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
1088 * then it is no longer reliable, so we stop using it and we mark the file
1089 * as failed in the superblock
1090 */
1091static void md_bitmap_file_kick(struct bitmap *bitmap)
1092{
1093 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
1094 bitmap_update_sb(bitmap);
1095
1096 if (bitmap->storage.file) {
1097 pr_warn("%s: kicking failed bitmap file %pD4 from array!\n",
1098 bmname(bitmap), bitmap->storage.file);
1099
1100 } else
1101 pr_warn("%s: disabling internal bitmap due to errors\n",
1102 bmname(bitmap));
1103 }
1104}
1105
1106enum bitmap_page_attr {
1107 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
1108 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
1109 * i.e. counter is 1 or 2. */
1110 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
1111};
1112
1113static inline void set_page_attr(struct bitmap *bitmap, int pnum,
1114 enum bitmap_page_attr attr)
1115{
1116 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
1117}
1118
1119static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
1120 enum bitmap_page_attr attr)
1121{
1122 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
1123}
1124
1125static inline int test_page_attr(struct bitmap *bitmap, int pnum,
1126 enum bitmap_page_attr attr)
1127{
1128 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
1129}
1130
1131static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
1132 enum bitmap_page_attr attr)
1133{
1134 return test_and_clear_bit((pnum<<2) + attr,
1135 bitmap->storage.filemap_attr);
1136}
1137/*
1138 * bitmap_file_set_bit -- called before performing a write to the md device
1139 * to set (and eventually sync) a particular bit in the bitmap file
1140 *
1141 * we set the bit immediately, then we record the page number so that
1142 * when an unplug occurs, we can flush the dirty pages out to disk
1143 */
1144static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
1145{
1146 unsigned long bit;
1147 struct page *page;
1148 void *kaddr;
1149 unsigned long chunk = block >> bitmap->counts.chunkshift;
1150 struct bitmap_storage *store = &bitmap->storage;
1151 unsigned long index = file_page_index(store, chunk);
1152 unsigned long node_offset = 0;
1153
1154 index += store->sb_index;
1155 if (mddev_is_clustered(bitmap->mddev))
1156 node_offset = bitmap->cluster_slot * store->file_pages;
1157
1158 page = filemap_get_page(&bitmap->storage, chunk);
1159 if (!page)
1160 return;
1161 bit = file_page_offset(&bitmap->storage, chunk);
1162
1163 /* set the bit */
1164 kaddr = kmap_atomic(page);
1165 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1166 set_bit(bit, kaddr);
1167 else
1168 set_bit_le(bit, kaddr);
1169 kunmap_atomic(kaddr);
1170 pr_debug("set file bit %lu page %lu\n", bit, index);
1171 /* record page number so it gets flushed to disk when unplug occurs */
1172 set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_DIRTY);
1173}
1174
1175static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
1176{
1177 unsigned long bit;
1178 struct page *page;
1179 void *paddr;
1180 unsigned long chunk = block >> bitmap->counts.chunkshift;
1181 struct bitmap_storage *store = &bitmap->storage;
1182 unsigned long index = file_page_index(store, chunk);
1183 unsigned long node_offset = 0;
1184
1185 index += store->sb_index;
1186 if (mddev_is_clustered(bitmap->mddev))
1187 node_offset = bitmap->cluster_slot * store->file_pages;
1188
1189 page = filemap_get_page(&bitmap->storage, chunk);
1190 if (!page)
1191 return;
1192 bit = file_page_offset(&bitmap->storage, chunk);
1193 paddr = kmap_atomic(page);
1194 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1195 clear_bit(bit, paddr);
1196 else
1197 clear_bit_le(bit, paddr);
1198 kunmap_atomic(paddr);
1199 if (!test_page_attr(bitmap, index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
1200 set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_PENDING);
1201 bitmap->allclean = 0;
1202 }
1203}
1204
1205static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
1206{
1207 unsigned long bit;
1208 struct page *page;
1209 void *paddr;
1210 unsigned long chunk = block >> bitmap->counts.chunkshift;
1211 int set = 0;
1212
1213 page = filemap_get_page(&bitmap->storage, chunk);
1214 if (!page)
1215 return -EINVAL;
1216 bit = file_page_offset(&bitmap->storage, chunk);
1217 paddr = kmap_atomic(page);
1218 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1219 set = test_bit(bit, paddr);
1220 else
1221 set = test_bit_le(bit, paddr);
1222 kunmap_atomic(paddr);
1223 return set;
1224}
1225
1226/* this gets called when the md device is ready to unplug its underlying
1227 * (slave) device queues -- before we let any writes go down, we need to
1228 * sync the dirty pages of the bitmap file to disk */
1229static void __bitmap_unplug(struct bitmap *bitmap)
1230{
1231 unsigned long i;
1232 int dirty, need_write;
1233 int writing = 0;
1234
1235 if (!__bitmap_enabled(bitmap))
1236 return;
1237
1238 /* look at each page to see if there are any set bits that need to be
1239 * flushed out to disk */
1240 for (i = 0; i < bitmap->storage.file_pages; i++) {
1241 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1242 need_write = test_and_clear_page_attr(bitmap, i,
1243 BITMAP_PAGE_NEEDWRITE);
1244 if (dirty || need_write) {
1245 if (!writing) {
1246 md_bitmap_wait_writes(bitmap);
1247 mddev_add_trace_msg(bitmap->mddev,
1248 "md bitmap_unplug");
1249 }
1250 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
1251 filemap_write_page(bitmap, i, false);
1252 writing = 1;
1253 }
1254 }
1255 if (writing)
1256 md_bitmap_wait_writes(bitmap);
1257
1258 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1259 md_bitmap_file_kick(bitmap);
1260}
1261
1262struct bitmap_unplug_work {
1263 struct work_struct work;
1264 struct bitmap *bitmap;
1265 struct completion *done;
1266};
1267
1268static void md_bitmap_unplug_fn(struct work_struct *work)
1269{
1270 struct bitmap_unplug_work *unplug_work =
1271 container_of(work, struct bitmap_unplug_work, work);
1272
1273 __bitmap_unplug(unplug_work->bitmap);
1274 complete(unplug_work->done);
1275}
1276
1277static void bitmap_unplug_async(struct bitmap *bitmap)
1278{
1279 DECLARE_COMPLETION_ONSTACK(done);
1280 struct bitmap_unplug_work unplug_work;
1281
1282 INIT_WORK_ONSTACK(&unplug_work.work, md_bitmap_unplug_fn);
1283 unplug_work.bitmap = bitmap;
1284 unplug_work.done = &done;
1285
1286 queue_work(md_bitmap_wq, &unplug_work.work);
1287 wait_for_completion(&done);
1288 destroy_work_on_stack(&unplug_work.work);
1289}
1290
1291static void bitmap_unplug(struct mddev *mddev, bool sync)
1292{
1293 struct bitmap *bitmap = mddev->bitmap;
1294
1295 if (!bitmap)
1296 return;
1297
1298 if (sync)
1299 __bitmap_unplug(bitmap);
1300 else
1301 bitmap_unplug_async(bitmap);
1302}
1303
1304static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1305
1306/*
1307 * Initialize the in-memory bitmap from the on-disk bitmap and set up the memory
1308 * mapping of the bitmap file.
1309 *
1310 * Special case: If there's no bitmap file, or if the bitmap file had been
1311 * previously kicked from the array, we mark all the bits as 1's in order to
1312 * cause a full resync.
1313 *
1314 * We ignore all bits for sectors that end earlier than 'start'.
1315 * This is used when reading an out-of-date bitmap.
1316 */
1317static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1318{
1319 bool outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1320 struct mddev *mddev = bitmap->mddev;
1321 unsigned long chunks = bitmap->counts.chunks;
1322 struct bitmap_storage *store = &bitmap->storage;
1323 struct file *file = store->file;
1324 unsigned long node_offset = 0;
1325 unsigned long bit_cnt = 0;
1326 unsigned long i;
1327 int ret;
1328
1329 if (!file && !mddev->bitmap_info.offset) {
1330 /* No permanent bitmap - fill with '1s'. */
1331 store->filemap = NULL;
1332 store->file_pages = 0;
1333 for (i = 0; i < chunks ; i++) {
1334 /* if the disk bit is set, set the memory bit */
1335 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1336 >= start);
1337 md_bitmap_set_memory_bits(bitmap,
1338 (sector_t)i << bitmap->counts.chunkshift,
1339 needed);
1340 }
1341 return 0;
1342 }
1343
1344 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
1345 pr_warn("%s: bitmap file too short %lu < %lu\n",
1346 bmname(bitmap),
1347 (unsigned long) i_size_read(file->f_mapping->host),
1348 store->bytes);
1349 ret = -ENOSPC;
1350 goto err;
1351 }
1352
1353 if (mddev_is_clustered(mddev))
1354 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1355
1356 for (i = 0; i < store->file_pages; i++) {
1357 struct page *page = store->filemap[i];
1358 int count;
1359
1360 /* unmap the old page, we're done with it */
1361 if (i == store->file_pages - 1)
1362 count = store->bytes - i * PAGE_SIZE;
1363 else
1364 count = PAGE_SIZE;
1365
1366 if (file)
1367 ret = read_file_page(file, i, bitmap, count, page);
1368 else
1369 ret = read_sb_page(mddev, 0, page, i + node_offset,
1370 count);
1371 if (ret)
1372 goto err;
1373 }
1374
1375 if (outofdate) {
1376 pr_warn("%s: bitmap file is out of date, doing full recovery\n",
1377 bmname(bitmap));
1378
1379 for (i = 0; i < store->file_pages; i++) {
1380 struct page *page = store->filemap[i];
1381 unsigned long offset = 0;
1382 void *paddr;
1383
1384 if (i == 0 && !mddev->bitmap_info.external)
1385 offset = sizeof(bitmap_super_t);
1386
1387 /*
1388 * If the bitmap is out of date, dirty the whole page
1389 * and write it out
1390 */
1391 paddr = kmap_atomic(page);
1392 memset(paddr + offset, 0xff, PAGE_SIZE - offset);
1393 kunmap_atomic(paddr);
1394
1395 filemap_write_page(bitmap, i, true);
1396 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags)) {
1397 ret = -EIO;
1398 goto err;
1399 }
1400 }
1401 }
1402
1403 for (i = 0; i < chunks; i++) {
1404 struct page *page = filemap_get_page(&bitmap->storage, i);
1405 unsigned long bit = file_page_offset(&bitmap->storage, i);
1406 void *paddr;
1407 bool was_set;
1408
1409 paddr = kmap_atomic(page);
1410 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1411 was_set = test_bit(bit, paddr);
1412 else
1413 was_set = test_bit_le(bit, paddr);
1414 kunmap_atomic(paddr);
1415
1416 if (was_set) {
1417 /* if the disk bit is set, set the memory bit */
1418 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1419 >= start);
1420 md_bitmap_set_memory_bits(bitmap,
1421 (sector_t)i << bitmap->counts.chunkshift,
1422 needed);
1423 bit_cnt++;
1424 }
1425 }
1426
1427 pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
1428 bmname(bitmap), store->file_pages,
1429 bit_cnt, chunks);
1430
1431 return 0;
1432
1433 err:
1434 pr_warn("%s: bitmap initialisation failed: %d\n",
1435 bmname(bitmap), ret);
1436 return ret;
1437}
1438
1439/* just flag bitmap pages as needing to be written. */
1440static void bitmap_write_all(struct mddev *mddev)
1441{
1442 int i;
1443 struct bitmap *bitmap = mddev->bitmap;
1444
1445 if (!bitmap || !bitmap->storage.filemap)
1446 return;
1447
1448 /* Only one copy, so nothing needed */
1449 if (bitmap->storage.file)
1450 return;
1451
1452 for (i = 0; i < bitmap->storage.file_pages; i++)
1453 set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
1454 bitmap->allclean = 0;
1455}
1456
1457static void md_bitmap_count_page(struct bitmap_counts *bitmap,
1458 sector_t offset, int inc)
1459{
1460 sector_t chunk = offset >> bitmap->chunkshift;
1461 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1462 bitmap->bp[page].count += inc;
1463 md_bitmap_checkfree(bitmap, page);
1464}
1465
1466static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1467{
1468 sector_t chunk = offset >> bitmap->chunkshift;
1469 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1470 struct bitmap_page *bp = &bitmap->bp[page];
1471
1472 if (!bp->pending)
1473 bp->pending = 1;
1474}
1475
1476static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1477 sector_t offset, sector_t *blocks,
1478 int create);
1479
1480static void mddev_set_timeout(struct mddev *mddev, unsigned long timeout,
1481 bool force)
1482{
1483 struct md_thread *thread;
1484
1485 rcu_read_lock();
1486 thread = rcu_dereference(mddev->thread);
1487
1488 if (!thread)
1489 goto out;
1490
1491 if (force || thread->timeout < MAX_SCHEDULE_TIMEOUT)
1492 thread->timeout = timeout;
1493
1494out:
1495 rcu_read_unlock();
1496}
1497
1498/*
1499 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1500 * out to disk
1501 */
1502static void bitmap_daemon_work(struct mddev *mddev)
1503{
1504 struct bitmap *bitmap;
1505 unsigned long j;
1506 unsigned long nextpage;
1507 sector_t blocks;
1508 struct bitmap_counts *counts;
1509
1510 /* Use a mutex to guard daemon_work against
1511 * bitmap_destroy.
1512 */
1513 mutex_lock(&mddev->bitmap_info.mutex);
1514 bitmap = mddev->bitmap;
1515 if (bitmap == NULL) {
1516 mutex_unlock(&mddev->bitmap_info.mutex);
1517 return;
1518 }
1519 if (time_before(jiffies, bitmap->daemon_lastrun
1520 + mddev->bitmap_info.daemon_sleep))
1521 goto done;
1522
1523 bitmap->daemon_lastrun = jiffies;
1524 if (bitmap->allclean) {
1525 mddev_set_timeout(mddev, MAX_SCHEDULE_TIMEOUT, true);
1526 goto done;
1527 }
1528 bitmap->allclean = 1;
1529
1530 mddev_add_trace_msg(bitmap->mddev, "md bitmap_daemon_work");
1531
1532 /* Any file-page which is PENDING now needs to be written.
1533 * So set NEEDWRITE now, then after we make any last-minute changes
1534 * we will write it.
1535 */
1536 for (j = 0; j < bitmap->storage.file_pages; j++)
1537 if (test_and_clear_page_attr(bitmap, j,
1538 BITMAP_PAGE_PENDING))
1539 set_page_attr(bitmap, j,
1540 BITMAP_PAGE_NEEDWRITE);
1541
1542 if (bitmap->need_sync &&
1543 mddev->bitmap_info.external == 0) {
1544 /* Arrange for superblock update as well as
1545 * other changes */
1546 bitmap_super_t *sb;
1547 bitmap->need_sync = 0;
1548 if (bitmap->storage.filemap) {
1549 sb = kmap_atomic(bitmap->storage.sb_page);
1550 sb->events_cleared =
1551 cpu_to_le64(bitmap->events_cleared);
1552 kunmap_atomic(sb);
1553 set_page_attr(bitmap, 0,
1554 BITMAP_PAGE_NEEDWRITE);
1555 }
1556 }
1557 /* Now look at the bitmap counters and if any are '2' or '1',
1558 * decrement and handle accordingly.
1559 */
1560 counts = &bitmap->counts;
1561 spin_lock_irq(&counts->lock);
1562 nextpage = 0;
1563 for (j = 0; j < counts->chunks; j++) {
1564 bitmap_counter_t *bmc;
1565 sector_t block = (sector_t)j << counts->chunkshift;
1566
1567 if (j == nextpage) {
1568 nextpage += PAGE_COUNTER_RATIO;
1569 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1570 j |= PAGE_COUNTER_MASK;
1571 continue;
1572 }
1573 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1574 }
1575
1576 bmc = md_bitmap_get_counter(counts, block, &blocks, 0);
1577 if (!bmc) {
1578 j |= PAGE_COUNTER_MASK;
1579 continue;
1580 }
1581 if (*bmc == 1 && !bitmap->need_sync) {
1582 /* We can clear the bit */
1583 *bmc = 0;
1584 md_bitmap_count_page(counts, block, -1);
1585 md_bitmap_file_clear_bit(bitmap, block);
1586 } else if (*bmc && *bmc <= 2) {
1587 *bmc = 1;
1588 md_bitmap_set_pending(counts, block);
1589 bitmap->allclean = 0;
1590 }
1591 }
1592 spin_unlock_irq(&counts->lock);
1593
1594 md_bitmap_wait_writes(bitmap);
1595 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1596 * DIRTY pages need to be written by bitmap_unplug so it can wait
1597 * for them.
1598 * If we find any DIRTY page we stop there and let bitmap_unplug
1599 * handle all the rest. This is important in the case where
1600 * the first blocking holds the superblock and it has been updated.
1601 * We mustn't write any other blocks before the superblock.
1602 */
1603 for (j = 0;
1604 j < bitmap->storage.file_pages
1605 && !test_bit(BITMAP_STALE, &bitmap->flags);
1606 j++) {
1607 if (test_page_attr(bitmap, j,
1608 BITMAP_PAGE_DIRTY))
1609 /* bitmap_unplug will handle the rest */
1610 break;
1611 if (bitmap->storage.filemap &&
1612 test_and_clear_page_attr(bitmap, j,
1613 BITMAP_PAGE_NEEDWRITE))
1614 filemap_write_page(bitmap, j, false);
1615 }
1616
1617 done:
1618 if (bitmap->allclean == 0)
1619 mddev_set_timeout(mddev, mddev->bitmap_info.daemon_sleep, true);
1620 mutex_unlock(&mddev->bitmap_info.mutex);
1621}
1622
1623static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
1624 sector_t offset, sector_t *blocks,
1625 int create)
1626__releases(bitmap->lock)
1627__acquires(bitmap->lock)
1628{
1629 /* If 'create', we might release the lock and reclaim it.
1630 * The lock must have been taken with interrupts enabled.
1631 * If !create, we don't release the lock.
1632 */
1633 sector_t chunk = offset >> bitmap->chunkshift;
1634 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1635 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1636 sector_t csize = ((sector_t)1) << bitmap->chunkshift;
1637 int err;
1638
1639 if (page >= bitmap->pages) {
1640 /*
1641 * This can happen if bitmap_start_sync goes beyond
1642 * End-of-device while looking for a whole page or
1643 * user set a huge number to sysfs bitmap_set_bits.
1644 */
1645 *blocks = csize - (offset & (csize - 1));
1646 return NULL;
1647 }
1648 err = md_bitmap_checkpage(bitmap, page, create, 0);
1649
1650 if (bitmap->bp[page].hijacked ||
1651 bitmap->bp[page].map == NULL)
1652 csize = ((sector_t)1) << (bitmap->chunkshift +
1653 PAGE_COUNTER_SHIFT);
1654
1655 *blocks = csize - (offset & (csize - 1));
1656
1657 if (err < 0)
1658 return NULL;
1659
1660 /* now locked ... */
1661
1662 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1663 /* should we use the first or second counter field
1664 * of the hijacked pointer? */
1665 int hi = (pageoff > PAGE_COUNTER_MASK);
1666 return &((bitmap_counter_t *)
1667 &bitmap->bp[page].map)[hi];
1668 } else /* page is allocated */
1669 return (bitmap_counter_t *)
1670 &(bitmap->bp[page].map[pageoff]);
1671}
1672
1673static int bitmap_startwrite(struct mddev *mddev, sector_t offset,
1674 unsigned long sectors)
1675{
1676 struct bitmap *bitmap = mddev->bitmap;
1677
1678 if (!bitmap)
1679 return 0;
1680
1681 while (sectors) {
1682 sector_t blocks;
1683 bitmap_counter_t *bmc;
1684
1685 spin_lock_irq(&bitmap->counts.lock);
1686 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1687 if (!bmc) {
1688 spin_unlock_irq(&bitmap->counts.lock);
1689 return 0;
1690 }
1691
1692 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1693 DEFINE_WAIT(__wait);
1694 /* note that it is safe to do the prepare_to_wait
1695 * after the test as long as we do it before dropping
1696 * the spinlock.
1697 */
1698 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1699 TASK_UNINTERRUPTIBLE);
1700 spin_unlock_irq(&bitmap->counts.lock);
1701 schedule();
1702 finish_wait(&bitmap->overflow_wait, &__wait);
1703 continue;
1704 }
1705
1706 switch (*bmc) {
1707 case 0:
1708 md_bitmap_file_set_bit(bitmap, offset);
1709 md_bitmap_count_page(&bitmap->counts, offset, 1);
1710 fallthrough;
1711 case 1:
1712 *bmc = 2;
1713 }
1714
1715 (*bmc)++;
1716
1717 spin_unlock_irq(&bitmap->counts.lock);
1718
1719 offset += blocks;
1720 if (sectors > blocks)
1721 sectors -= blocks;
1722 else
1723 sectors = 0;
1724 }
1725 return 0;
1726}
1727
1728static void bitmap_endwrite(struct mddev *mddev, sector_t offset,
1729 unsigned long sectors)
1730{
1731 struct bitmap *bitmap = mddev->bitmap;
1732
1733 if (!bitmap)
1734 return;
1735
1736 while (sectors) {
1737 sector_t blocks;
1738 unsigned long flags;
1739 bitmap_counter_t *bmc;
1740
1741 spin_lock_irqsave(&bitmap->counts.lock, flags);
1742 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1743 if (!bmc) {
1744 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1745 return;
1746 }
1747
1748 if (!bitmap->mddev->degraded) {
1749 if (bitmap->events_cleared < bitmap->mddev->events) {
1750 bitmap->events_cleared = bitmap->mddev->events;
1751 bitmap->need_sync = 1;
1752 sysfs_notify_dirent_safe(
1753 bitmap->sysfs_can_clear);
1754 }
1755 } else if (!NEEDED(*bmc)) {
1756 *bmc |= NEEDED_MASK;
1757 }
1758
1759 if (COUNTER(*bmc) == COUNTER_MAX)
1760 wake_up(&bitmap->overflow_wait);
1761
1762 (*bmc)--;
1763 if (*bmc <= 2) {
1764 md_bitmap_set_pending(&bitmap->counts, offset);
1765 bitmap->allclean = 0;
1766 }
1767 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1768 offset += blocks;
1769 if (sectors > blocks)
1770 sectors -= blocks;
1771 else
1772 sectors = 0;
1773 }
1774}
1775
1776static bool __bitmap_start_sync(struct bitmap *bitmap, sector_t offset,
1777 sector_t *blocks, bool degraded)
1778{
1779 bitmap_counter_t *bmc;
1780 bool rv;
1781
1782 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1783 *blocks = 1024;
1784 return true; /* always resync if no bitmap */
1785 }
1786 spin_lock_irq(&bitmap->counts.lock);
1787
1788 rv = false;
1789 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1790 if (bmc) {
1791 /* locked */
1792 if (RESYNC(*bmc)) {
1793 rv = true;
1794 } else if (NEEDED(*bmc)) {
1795 rv = true;
1796 if (!degraded) { /* don't set/clear bits if degraded */
1797 *bmc |= RESYNC_MASK;
1798 *bmc &= ~NEEDED_MASK;
1799 }
1800 }
1801 }
1802 spin_unlock_irq(&bitmap->counts.lock);
1803
1804 return rv;
1805}
1806
1807static bool bitmap_start_sync(struct mddev *mddev, sector_t offset,
1808 sector_t *blocks, bool degraded)
1809{
1810 /* bitmap_start_sync must always report on multiples of whole
1811 * pages, otherwise resync (which is very PAGE_SIZE based) will
1812 * get confused.
1813 * So call __bitmap_start_sync repeatedly (if needed) until
1814 * At least PAGE_SIZE>>9 blocks are covered.
1815 * Return the 'or' of the result.
1816 */
1817 bool rv = false;
1818 sector_t blocks1;
1819
1820 *blocks = 0;
1821 while (*blocks < (PAGE_SIZE>>9)) {
1822 rv |= __bitmap_start_sync(mddev->bitmap, offset,
1823 &blocks1, degraded);
1824 offset += blocks1;
1825 *blocks += blocks1;
1826 }
1827
1828 return rv;
1829}
1830
1831static void __bitmap_end_sync(struct bitmap *bitmap, sector_t offset,
1832 sector_t *blocks, bool aborted)
1833{
1834 bitmap_counter_t *bmc;
1835 unsigned long flags;
1836
1837 if (bitmap == NULL) {
1838 *blocks = 1024;
1839 return;
1840 }
1841 spin_lock_irqsave(&bitmap->counts.lock, flags);
1842 bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1843 if (bmc == NULL)
1844 goto unlock;
1845 /* locked */
1846 if (RESYNC(*bmc)) {
1847 *bmc &= ~RESYNC_MASK;
1848
1849 if (!NEEDED(*bmc) && aborted)
1850 *bmc |= NEEDED_MASK;
1851 else {
1852 if (*bmc <= 2) {
1853 md_bitmap_set_pending(&bitmap->counts, offset);
1854 bitmap->allclean = 0;
1855 }
1856 }
1857 }
1858 unlock:
1859 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1860}
1861
1862static void bitmap_end_sync(struct mddev *mddev, sector_t offset,
1863 sector_t *blocks)
1864{
1865 __bitmap_end_sync(mddev->bitmap, offset, blocks, true);
1866}
1867
1868static void bitmap_close_sync(struct mddev *mddev)
1869{
1870 /* Sync has finished, and any bitmap chunks that weren't synced
1871 * properly have been aborted. It remains to us to clear the
1872 * RESYNC bit wherever it is still on
1873 */
1874 sector_t sector = 0;
1875 sector_t blocks;
1876 struct bitmap *bitmap = mddev->bitmap;
1877
1878 if (!bitmap)
1879 return;
1880
1881 while (sector < bitmap->mddev->resync_max_sectors) {
1882 __bitmap_end_sync(bitmap, sector, &blocks, false);
1883 sector += blocks;
1884 }
1885}
1886
1887static void bitmap_cond_end_sync(struct mddev *mddev, sector_t sector,
1888 bool force)
1889{
1890 sector_t s = 0;
1891 sector_t blocks;
1892 struct bitmap *bitmap = mddev->bitmap;
1893
1894 if (!bitmap)
1895 return;
1896 if (sector == 0) {
1897 bitmap->last_end_sync = jiffies;
1898 return;
1899 }
1900 if (!force && time_before(jiffies, (bitmap->last_end_sync
1901 + bitmap->mddev->bitmap_info.daemon_sleep)))
1902 return;
1903 wait_event(bitmap->mddev->recovery_wait,
1904 atomic_read(&bitmap->mddev->recovery_active) == 0);
1905
1906 bitmap->mddev->curr_resync_completed = sector;
1907 set_bit(MD_SB_CHANGE_CLEAN, &bitmap->mddev->sb_flags);
1908 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1909 s = 0;
1910 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1911 __bitmap_end_sync(bitmap, s, &blocks, false);
1912 s += blocks;
1913 }
1914 bitmap->last_end_sync = jiffies;
1915 sysfs_notify_dirent_safe(bitmap->mddev->sysfs_completed);
1916}
1917
1918static void bitmap_sync_with_cluster(struct mddev *mddev,
1919 sector_t old_lo, sector_t old_hi,
1920 sector_t new_lo, sector_t new_hi)
1921{
1922 struct bitmap *bitmap = mddev->bitmap;
1923 sector_t sector, blocks = 0;
1924
1925 for (sector = old_lo; sector < new_lo; ) {
1926 __bitmap_end_sync(bitmap, sector, &blocks, false);
1927 sector += blocks;
1928 }
1929 WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
1930
1931 for (sector = old_hi; sector < new_hi; ) {
1932 bitmap_start_sync(mddev, sector, &blocks, false);
1933 sector += blocks;
1934 }
1935 WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
1936}
1937
1938static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1939{
1940 /* For each chunk covered by any of these sectors, set the
1941 * counter to 2 and possibly set resync_needed. They should all
1942 * be 0 at this point
1943 */
1944
1945 sector_t secs;
1946 bitmap_counter_t *bmc;
1947 spin_lock_irq(&bitmap->counts.lock);
1948 bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1949 if (!bmc) {
1950 spin_unlock_irq(&bitmap->counts.lock);
1951 return;
1952 }
1953 if (!*bmc) {
1954 *bmc = 2;
1955 md_bitmap_count_page(&bitmap->counts, offset, 1);
1956 md_bitmap_set_pending(&bitmap->counts, offset);
1957 bitmap->allclean = 0;
1958 }
1959 if (needed)
1960 *bmc |= NEEDED_MASK;
1961 spin_unlock_irq(&bitmap->counts.lock);
1962}
1963
1964/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1965static void bitmap_dirty_bits(struct mddev *mddev, unsigned long s,
1966 unsigned long e)
1967{
1968 unsigned long chunk;
1969 struct bitmap *bitmap = mddev->bitmap;
1970
1971 if (!bitmap)
1972 return;
1973
1974 for (chunk = s; chunk <= e; chunk++) {
1975 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1976
1977 md_bitmap_set_memory_bits(bitmap, sec, 1);
1978 md_bitmap_file_set_bit(bitmap, sec);
1979 if (sec < bitmap->mddev->recovery_cp)
1980 /* We are asserting that the array is dirty,
1981 * so move the recovery_cp address back so
1982 * that it is obvious that it is dirty
1983 */
1984 bitmap->mddev->recovery_cp = sec;
1985 }
1986}
1987
1988static void bitmap_flush(struct mddev *mddev)
1989{
1990 struct bitmap *bitmap = mddev->bitmap;
1991 long sleep;
1992
1993 if (!bitmap) /* there was no bitmap */
1994 return;
1995
1996 /* run the daemon_work three time to ensure everything is flushed
1997 * that can be
1998 */
1999 sleep = mddev->bitmap_info.daemon_sleep * 2;
2000 bitmap->daemon_lastrun -= sleep;
2001 bitmap_daemon_work(mddev);
2002 bitmap->daemon_lastrun -= sleep;
2003 bitmap_daemon_work(mddev);
2004 bitmap->daemon_lastrun -= sleep;
2005 bitmap_daemon_work(mddev);
2006 if (mddev->bitmap_info.external)
2007 md_super_wait(mddev);
2008 bitmap_update_sb(bitmap);
2009}
2010
2011static void md_bitmap_free(void *data)
2012{
2013 unsigned long k, pages;
2014 struct bitmap_page *bp;
2015 struct bitmap *bitmap = data;
2016
2017 if (!bitmap) /* there was no bitmap */
2018 return;
2019
2020 if (bitmap->sysfs_can_clear)
2021 sysfs_put(bitmap->sysfs_can_clear);
2022
2023 if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
2024 bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
2025 md_cluster_stop(bitmap->mddev);
2026
2027 /* Shouldn't be needed - but just in case.... */
2028 wait_event(bitmap->write_wait,
2029 atomic_read(&bitmap->pending_writes) == 0);
2030
2031 /* release the bitmap file */
2032 md_bitmap_file_unmap(&bitmap->storage);
2033
2034 bp = bitmap->counts.bp;
2035 pages = bitmap->counts.pages;
2036
2037 /* free all allocated memory */
2038
2039 if (bp) /* deallocate the page memory */
2040 for (k = 0; k < pages; k++)
2041 if (bp[k].map && !bp[k].hijacked)
2042 kfree(bp[k].map);
2043 kfree(bp);
2044 kfree(bitmap);
2045}
2046
2047static void bitmap_start_behind_write(struct mddev *mddev)
2048{
2049 struct bitmap *bitmap = mddev->bitmap;
2050 int bw;
2051
2052 if (!bitmap)
2053 return;
2054
2055 atomic_inc(&bitmap->behind_writes);
2056 bw = atomic_read(&bitmap->behind_writes);
2057 if (bw > bitmap->behind_writes_used)
2058 bitmap->behind_writes_used = bw;
2059
2060 pr_debug("inc write-behind count %d/%lu\n",
2061 bw, bitmap->mddev->bitmap_info.max_write_behind);
2062}
2063
2064static void bitmap_end_behind_write(struct mddev *mddev)
2065{
2066 struct bitmap *bitmap = mddev->bitmap;
2067
2068 if (!bitmap)
2069 return;
2070
2071 if (atomic_dec_and_test(&bitmap->behind_writes))
2072 wake_up(&bitmap->behind_wait);
2073 pr_debug("dec write-behind count %d/%lu\n",
2074 atomic_read(&bitmap->behind_writes),
2075 bitmap->mddev->bitmap_info.max_write_behind);
2076}
2077
2078static void bitmap_wait_behind_writes(struct mddev *mddev)
2079{
2080 struct bitmap *bitmap = mddev->bitmap;
2081
2082 /* wait for behind writes to complete */
2083 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2084 pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
2085 mdname(mddev));
2086 /* need to kick something here to make sure I/O goes? */
2087 wait_event(bitmap->behind_wait,
2088 atomic_read(&bitmap->behind_writes) == 0);
2089 }
2090}
2091
2092static void bitmap_destroy(struct mddev *mddev)
2093{
2094 struct bitmap *bitmap = mddev->bitmap;
2095
2096 if (!bitmap) /* there was no bitmap */
2097 return;
2098
2099 bitmap_wait_behind_writes(mddev);
2100 if (!mddev->serialize_policy)
2101 mddev_destroy_serial_pool(mddev, NULL);
2102
2103 mutex_lock(&mddev->bitmap_info.mutex);
2104 spin_lock(&mddev->lock);
2105 mddev->bitmap = NULL; /* disconnect from the md device */
2106 spin_unlock(&mddev->lock);
2107 mutex_unlock(&mddev->bitmap_info.mutex);
2108 mddev_set_timeout(mddev, MAX_SCHEDULE_TIMEOUT, true);
2109
2110 md_bitmap_free(bitmap);
2111}
2112
2113/*
2114 * initialize the bitmap structure
2115 * if this returns an error, bitmap_destroy must be called to do clean up
2116 * once mddev->bitmap is set
2117 */
2118static struct bitmap *__bitmap_create(struct mddev *mddev, int slot)
2119{
2120 struct bitmap *bitmap;
2121 sector_t blocks = mddev->resync_max_sectors;
2122 struct file *file = mddev->bitmap_info.file;
2123 int err;
2124 struct kernfs_node *bm = NULL;
2125
2126 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
2127
2128 BUG_ON(file && mddev->bitmap_info.offset);
2129
2130 if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
2131 pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
2132 mdname(mddev));
2133 return ERR_PTR(-EBUSY);
2134 }
2135
2136 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
2137 if (!bitmap)
2138 return ERR_PTR(-ENOMEM);
2139
2140 spin_lock_init(&bitmap->counts.lock);
2141 atomic_set(&bitmap->pending_writes, 0);
2142 init_waitqueue_head(&bitmap->write_wait);
2143 init_waitqueue_head(&bitmap->overflow_wait);
2144 init_waitqueue_head(&bitmap->behind_wait);
2145
2146 bitmap->mddev = mddev;
2147 bitmap->cluster_slot = slot;
2148
2149 if (mddev->kobj.sd)
2150 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
2151 if (bm) {
2152 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
2153 sysfs_put(bm);
2154 } else
2155 bitmap->sysfs_can_clear = NULL;
2156
2157 bitmap->storage.file = file;
2158 if (file) {
2159 get_file(file);
2160 /* As future accesses to this file will use bmap,
2161 * and bypass the page cache, we must sync the file
2162 * first.
2163 */
2164 vfs_fsync(file, 1);
2165 }
2166 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
2167 if (!mddev->bitmap_info.external) {
2168 /*
2169 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
2170 * instructing us to create a new on-disk bitmap instance.
2171 */
2172 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
2173 err = md_bitmap_new_disk_sb(bitmap);
2174 else
2175 err = md_bitmap_read_sb(bitmap);
2176 } else {
2177 err = 0;
2178 if (mddev->bitmap_info.chunksize == 0 ||
2179 mddev->bitmap_info.daemon_sleep == 0)
2180 /* chunksize and time_base need to be
2181 * set first. */
2182 err = -EINVAL;
2183 }
2184 if (err)
2185 goto error;
2186
2187 bitmap->daemon_lastrun = jiffies;
2188 err = __bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize,
2189 true);
2190 if (err)
2191 goto error;
2192
2193 pr_debug("created bitmap (%lu pages) for device %s\n",
2194 bitmap->counts.pages, bmname(bitmap));
2195
2196 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
2197 if (err)
2198 goto error;
2199
2200 return bitmap;
2201 error:
2202 md_bitmap_free(bitmap);
2203 return ERR_PTR(err);
2204}
2205
2206static int bitmap_create(struct mddev *mddev, int slot)
2207{
2208 struct bitmap *bitmap = __bitmap_create(mddev, slot);
2209
2210 if (IS_ERR(bitmap))
2211 return PTR_ERR(bitmap);
2212
2213 mddev->bitmap = bitmap;
2214 return 0;
2215}
2216
2217static int bitmap_load(struct mddev *mddev)
2218{
2219 int err = 0;
2220 sector_t start = 0;
2221 sector_t sector = 0;
2222 struct bitmap *bitmap = mddev->bitmap;
2223 struct md_rdev *rdev;
2224
2225 if (!bitmap)
2226 goto out;
2227
2228 rdev_for_each(rdev, mddev)
2229 mddev_create_serial_pool(mddev, rdev);
2230
2231 if (mddev_is_clustered(mddev))
2232 md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
2233
2234 /* Clear out old bitmap info first: Either there is none, or we
2235 * are resuming after someone else has possibly changed things,
2236 * so we should forget old cached info.
2237 * All chunks should be clean, but some might need_sync.
2238 */
2239 while (sector < mddev->resync_max_sectors) {
2240 sector_t blocks;
2241 bitmap_start_sync(mddev, sector, &blocks, false);
2242 sector += blocks;
2243 }
2244 bitmap_close_sync(mddev);
2245
2246 if (mddev->degraded == 0
2247 || bitmap->events_cleared == mddev->events)
2248 /* no need to keep dirty bits to optimise a
2249 * re-add of a missing device */
2250 start = mddev->recovery_cp;
2251
2252 mutex_lock(&mddev->bitmap_info.mutex);
2253 err = md_bitmap_init_from_disk(bitmap, start);
2254 mutex_unlock(&mddev->bitmap_info.mutex);
2255
2256 if (err)
2257 goto out;
2258 clear_bit(BITMAP_STALE, &bitmap->flags);
2259
2260 /* Kick recovery in case any bits were set */
2261 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
2262
2263 mddev_set_timeout(mddev, mddev->bitmap_info.daemon_sleep, true);
2264 md_wakeup_thread(mddev->thread);
2265
2266 bitmap_update_sb(bitmap);
2267
2268 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
2269 err = -EIO;
2270out:
2271 return err;
2272}
2273
2274/* caller need to free returned bitmap with md_bitmap_free() */
2275static void *bitmap_get_from_slot(struct mddev *mddev, int slot)
2276{
2277 int rv = 0;
2278 struct bitmap *bitmap;
2279
2280 bitmap = __bitmap_create(mddev, slot);
2281 if (IS_ERR(bitmap)) {
2282 rv = PTR_ERR(bitmap);
2283 return ERR_PTR(rv);
2284 }
2285
2286 rv = md_bitmap_init_from_disk(bitmap, 0);
2287 if (rv) {
2288 md_bitmap_free(bitmap);
2289 return ERR_PTR(rv);
2290 }
2291
2292 return bitmap;
2293}
2294
2295/* Loads the bitmap associated with slot and copies the resync information
2296 * to our bitmap
2297 */
2298static int bitmap_copy_from_slot(struct mddev *mddev, int slot, sector_t *low,
2299 sector_t *high, bool clear_bits)
2300{
2301 int rv = 0, i, j;
2302 sector_t block, lo = 0, hi = 0;
2303 struct bitmap_counts *counts;
2304 struct bitmap *bitmap;
2305
2306 bitmap = bitmap_get_from_slot(mddev, slot);
2307 if (IS_ERR(bitmap)) {
2308 pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
2309 return -1;
2310 }
2311
2312 counts = &bitmap->counts;
2313 for (j = 0; j < counts->chunks; j++) {
2314 block = (sector_t)j << counts->chunkshift;
2315 if (md_bitmap_file_test_bit(bitmap, block)) {
2316 if (!lo)
2317 lo = block;
2318 hi = block;
2319 md_bitmap_file_clear_bit(bitmap, block);
2320 md_bitmap_set_memory_bits(mddev->bitmap, block, 1);
2321 md_bitmap_file_set_bit(mddev->bitmap, block);
2322 }
2323 }
2324
2325 if (clear_bits) {
2326 bitmap_update_sb(bitmap);
2327 /* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
2328 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
2329 for (i = 0; i < bitmap->storage.file_pages; i++)
2330 if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
2331 set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
2332 __bitmap_unplug(bitmap);
2333 }
2334 __bitmap_unplug(mddev->bitmap);
2335 *low = lo;
2336 *high = hi;
2337 md_bitmap_free(bitmap);
2338
2339 return rv;
2340}
2341
2342static void bitmap_set_pages(void *data, unsigned long pages)
2343{
2344 struct bitmap *bitmap = data;
2345
2346 bitmap->counts.pages = pages;
2347}
2348
2349static int bitmap_get_stats(void *data, struct md_bitmap_stats *stats)
2350{
2351 struct bitmap_storage *storage;
2352 struct bitmap_counts *counts;
2353 struct bitmap *bitmap = data;
2354 bitmap_super_t *sb;
2355
2356 if (!bitmap)
2357 return -ENOENT;
2358 if (bitmap->mddev->bitmap_info.external)
2359 return -ENOENT;
2360 if (!bitmap->storage.sb_page) /* no superblock */
2361 return -EINVAL;
2362 sb = kmap_local_page(bitmap->storage.sb_page);
2363 stats->sync_size = le64_to_cpu(sb->sync_size);
2364 kunmap_local(sb);
2365
2366 counts = &bitmap->counts;
2367 stats->missing_pages = counts->missing_pages;
2368 stats->pages = counts->pages;
2369
2370 storage = &bitmap->storage;
2371 stats->file_pages = storage->file_pages;
2372 stats->file = storage->file;
2373
2374 stats->behind_writes = atomic_read(&bitmap->behind_writes);
2375 stats->behind_wait = wq_has_sleeper(&bitmap->behind_wait);
2376 stats->events_cleared = bitmap->events_cleared;
2377 return 0;
2378}
2379
2380static int __bitmap_resize(struct bitmap *bitmap, sector_t blocks,
2381 int chunksize, bool init)
2382{
2383 /* If chunk_size is 0, choose an appropriate chunk size.
2384 * Then possibly allocate new storage space.
2385 * Then quiesce, copy bits, replace bitmap, and re-start
2386 *
2387 * This function is called both to set up the initial bitmap
2388 * and to resize the bitmap while the array is active.
2389 * If this happens as a result of the array being resized,
2390 * chunksize will be zero, and we need to choose a suitable
2391 * chunksize, otherwise we use what we are given.
2392 */
2393 struct bitmap_storage store;
2394 struct bitmap_counts old_counts;
2395 unsigned long chunks;
2396 sector_t block;
2397 sector_t old_blocks, new_blocks;
2398 int chunkshift;
2399 int ret = 0;
2400 long pages;
2401 struct bitmap_page *new_bp;
2402
2403 if (bitmap->storage.file && !init) {
2404 pr_info("md: cannot resize file-based bitmap\n");
2405 return -EINVAL;
2406 }
2407
2408 if (chunksize == 0) {
2409 /* If there is enough space, leave the chunk size unchanged,
2410 * else increase by factor of two until there is enough space.
2411 */
2412 long bytes;
2413 long space = bitmap->mddev->bitmap_info.space;
2414
2415 if (space == 0) {
2416 /* We don't know how much space there is, so limit
2417 * to current size - in sectors.
2418 */
2419 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
2420 if (!bitmap->mddev->bitmap_info.external)
2421 bytes += sizeof(bitmap_super_t);
2422 space = DIV_ROUND_UP(bytes, 512);
2423 bitmap->mddev->bitmap_info.space = space;
2424 }
2425 chunkshift = bitmap->counts.chunkshift;
2426 chunkshift--;
2427 do {
2428 /* 'chunkshift' is shift from block size to chunk size */
2429 chunkshift++;
2430 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2431 bytes = DIV_ROUND_UP(chunks, 8);
2432 if (!bitmap->mddev->bitmap_info.external)
2433 bytes += sizeof(bitmap_super_t);
2434 } while (bytes > (space << 9) && (chunkshift + BITMAP_BLOCK_SHIFT) <
2435 (BITS_PER_BYTE * sizeof(((bitmap_super_t *)0)->chunksize) - 1));
2436 } else
2437 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
2438
2439 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2440 memset(&store, 0, sizeof(store));
2441 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2442 ret = md_bitmap_storage_alloc(&store, chunks,
2443 !bitmap->mddev->bitmap_info.external,
2444 mddev_is_clustered(bitmap->mddev)
2445 ? bitmap->cluster_slot : 0);
2446 if (ret) {
2447 md_bitmap_file_unmap(&store);
2448 goto err;
2449 }
2450
2451 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2452
2453 new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
2454 ret = -ENOMEM;
2455 if (!new_bp) {
2456 md_bitmap_file_unmap(&store);
2457 goto err;
2458 }
2459
2460 if (!init)
2461 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2462
2463 store.file = bitmap->storage.file;
2464 bitmap->storage.file = NULL;
2465
2466 if (store.sb_page && bitmap->storage.sb_page)
2467 memcpy(page_address(store.sb_page),
2468 page_address(bitmap->storage.sb_page),
2469 sizeof(bitmap_super_t));
2470 spin_lock_irq(&bitmap->counts.lock);
2471 md_bitmap_file_unmap(&bitmap->storage);
2472 bitmap->storage = store;
2473
2474 old_counts = bitmap->counts;
2475 bitmap->counts.bp = new_bp;
2476 bitmap->counts.pages = pages;
2477 bitmap->counts.missing_pages = pages;
2478 bitmap->counts.chunkshift = chunkshift;
2479 bitmap->counts.chunks = chunks;
2480 bitmap->mddev->bitmap_info.chunksize = 1UL << (chunkshift +
2481 BITMAP_BLOCK_SHIFT);
2482
2483 blocks = min(old_counts.chunks << old_counts.chunkshift,
2484 chunks << chunkshift);
2485
2486 /* For cluster raid, need to pre-allocate bitmap */
2487 if (mddev_is_clustered(bitmap->mddev)) {
2488 unsigned long page;
2489 for (page = 0; page < pages; page++) {
2490 ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1);
2491 if (ret) {
2492 unsigned long k;
2493
2494 /* deallocate the page memory */
2495 for (k = 0; k < page; k++) {
2496 kfree(new_bp[k].map);
2497 }
2498 kfree(new_bp);
2499
2500 /* restore some fields from old_counts */
2501 bitmap->counts.bp = old_counts.bp;
2502 bitmap->counts.pages = old_counts.pages;
2503 bitmap->counts.missing_pages = old_counts.pages;
2504 bitmap->counts.chunkshift = old_counts.chunkshift;
2505 bitmap->counts.chunks = old_counts.chunks;
2506 bitmap->mddev->bitmap_info.chunksize =
2507 1UL << (old_counts.chunkshift + BITMAP_BLOCK_SHIFT);
2508 blocks = old_counts.chunks << old_counts.chunkshift;
2509 pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
2510 break;
2511 } else
2512 bitmap->counts.bp[page].count += 1;
2513 }
2514 }
2515
2516 for (block = 0; block < blocks; ) {
2517 bitmap_counter_t *bmc_old, *bmc_new;
2518 int set;
2519
2520 bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0);
2521 set = bmc_old && NEEDED(*bmc_old);
2522
2523 if (set) {
2524 bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2525 if (bmc_new) {
2526 if (*bmc_new == 0) {
2527 /* need to set on-disk bits too. */
2528 sector_t end = block + new_blocks;
2529 sector_t start = block >> chunkshift;
2530
2531 start <<= chunkshift;
2532 while (start < end) {
2533 md_bitmap_file_set_bit(bitmap, block);
2534 start += 1 << chunkshift;
2535 }
2536 *bmc_new = 2;
2537 md_bitmap_count_page(&bitmap->counts, block, 1);
2538 md_bitmap_set_pending(&bitmap->counts, block);
2539 }
2540 *bmc_new |= NEEDED_MASK;
2541 }
2542 if (new_blocks < old_blocks)
2543 old_blocks = new_blocks;
2544 }
2545 block += old_blocks;
2546 }
2547
2548 if (bitmap->counts.bp != old_counts.bp) {
2549 unsigned long k;
2550 for (k = 0; k < old_counts.pages; k++)
2551 if (!old_counts.bp[k].hijacked)
2552 kfree(old_counts.bp[k].map);
2553 kfree(old_counts.bp);
2554 }
2555
2556 if (!init) {
2557 int i;
2558 while (block < (chunks << chunkshift)) {
2559 bitmap_counter_t *bmc;
2560 bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
2561 if (bmc) {
2562 /* new space. It needs to be resynced, so
2563 * we set NEEDED_MASK.
2564 */
2565 if (*bmc == 0) {
2566 *bmc = NEEDED_MASK | 2;
2567 md_bitmap_count_page(&bitmap->counts, block, 1);
2568 md_bitmap_set_pending(&bitmap->counts, block);
2569 }
2570 }
2571 block += new_blocks;
2572 }
2573 for (i = 0; i < bitmap->storage.file_pages; i++)
2574 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
2575 }
2576 spin_unlock_irq(&bitmap->counts.lock);
2577
2578 if (!init) {
2579 __bitmap_unplug(bitmap);
2580 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2581 }
2582 ret = 0;
2583err:
2584 return ret;
2585}
2586
2587static int bitmap_resize(struct mddev *mddev, sector_t blocks, int chunksize,
2588 bool init)
2589{
2590 struct bitmap *bitmap = mddev->bitmap;
2591
2592 if (!bitmap)
2593 return 0;
2594
2595 return __bitmap_resize(bitmap, blocks, chunksize, init);
2596}
2597
2598static ssize_t
2599location_show(struct mddev *mddev, char *page)
2600{
2601 ssize_t len;
2602 if (mddev->bitmap_info.file)
2603 len = sprintf(page, "file");
2604 else if (mddev->bitmap_info.offset)
2605 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
2606 else
2607 len = sprintf(page, "none");
2608 len += sprintf(page+len, "\n");
2609 return len;
2610}
2611
2612static ssize_t
2613location_store(struct mddev *mddev, const char *buf, size_t len)
2614{
2615 int rv;
2616
2617 rv = mddev_suspend_and_lock(mddev);
2618 if (rv)
2619 return rv;
2620
2621 if (mddev->pers) {
2622 if (mddev->recovery || mddev->sync_thread) {
2623 rv = -EBUSY;
2624 goto out;
2625 }
2626 }
2627
2628 if (mddev->bitmap || mddev->bitmap_info.file ||
2629 mddev->bitmap_info.offset) {
2630 /* bitmap already configured. Only option is to clear it */
2631 if (strncmp(buf, "none", 4) != 0) {
2632 rv = -EBUSY;
2633 goto out;
2634 }
2635
2636 bitmap_destroy(mddev);
2637 mddev->bitmap_info.offset = 0;
2638 if (mddev->bitmap_info.file) {
2639 struct file *f = mddev->bitmap_info.file;
2640 mddev->bitmap_info.file = NULL;
2641 fput(f);
2642 }
2643 } else {
2644 /* No bitmap, OK to set a location */
2645 long long offset;
2646
2647 if (strncmp(buf, "none", 4) == 0)
2648 /* nothing to be done */;
2649 else if (strncmp(buf, "file:", 5) == 0) {
2650 /* Not supported yet */
2651 rv = -EINVAL;
2652 goto out;
2653 } else {
2654 if (buf[0] == '+')
2655 rv = kstrtoll(buf+1, 10, &offset);
2656 else
2657 rv = kstrtoll(buf, 10, &offset);
2658 if (rv)
2659 goto out;
2660 if (offset == 0) {
2661 rv = -EINVAL;
2662 goto out;
2663 }
2664 if (mddev->bitmap_info.external == 0 &&
2665 mddev->major_version == 0 &&
2666 offset != mddev->bitmap_info.default_offset) {
2667 rv = -EINVAL;
2668 goto out;
2669 }
2670
2671 mddev->bitmap_info.offset = offset;
2672 rv = bitmap_create(mddev, -1);
2673 if (rv)
2674 goto out;
2675
2676 rv = bitmap_load(mddev);
2677 if (rv) {
2678 mddev->bitmap_info.offset = 0;
2679 bitmap_destroy(mddev);
2680 goto out;
2681 }
2682 }
2683 }
2684 if (!mddev->external) {
2685 /* Ensure new bitmap info is stored in
2686 * metadata promptly.
2687 */
2688 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2689 md_wakeup_thread(mddev->thread);
2690 }
2691 rv = 0;
2692out:
2693 mddev_unlock_and_resume(mddev);
2694 if (rv)
2695 return rv;
2696 return len;
2697}
2698
2699static struct md_sysfs_entry bitmap_location =
2700__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2701
2702/* 'bitmap/space' is the space available at 'location' for the
2703 * bitmap. This allows the kernel to know when it is safe to
2704 * resize the bitmap to match a resized array.
2705 */
2706static ssize_t
2707space_show(struct mddev *mddev, char *page)
2708{
2709 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2710}
2711
2712static ssize_t
2713space_store(struct mddev *mddev, const char *buf, size_t len)
2714{
2715 struct bitmap *bitmap;
2716 unsigned long sectors;
2717 int rv;
2718
2719 rv = kstrtoul(buf, 10, §ors);
2720 if (rv)
2721 return rv;
2722
2723 if (sectors == 0)
2724 return -EINVAL;
2725
2726 bitmap = mddev->bitmap;
2727 if (bitmap && sectors < (bitmap->storage.bytes + 511) >> 9)
2728 return -EFBIG; /* Bitmap is too big for this small space */
2729
2730 /* could make sure it isn't too big, but that isn't really
2731 * needed - user-space should be careful.
2732 */
2733 mddev->bitmap_info.space = sectors;
2734 return len;
2735}
2736
2737static struct md_sysfs_entry bitmap_space =
2738__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2739
2740static ssize_t
2741timeout_show(struct mddev *mddev, char *page)
2742{
2743 ssize_t len;
2744 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2745 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2746
2747 len = sprintf(page, "%lu", secs);
2748 if (jifs)
2749 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2750 len += sprintf(page+len, "\n");
2751 return len;
2752}
2753
2754static ssize_t
2755timeout_store(struct mddev *mddev, const char *buf, size_t len)
2756{
2757 /* timeout can be set at any time */
2758 unsigned long timeout;
2759 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2760 if (rv)
2761 return rv;
2762
2763 /* just to make sure we don't overflow... */
2764 if (timeout >= LONG_MAX / HZ)
2765 return -EINVAL;
2766
2767 timeout = timeout * HZ / 10000;
2768
2769 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2770 timeout = MAX_SCHEDULE_TIMEOUT-1;
2771 if (timeout < 1)
2772 timeout = 1;
2773
2774 mddev->bitmap_info.daemon_sleep = timeout;
2775 mddev_set_timeout(mddev, timeout, false);
2776 md_wakeup_thread(mddev->thread);
2777
2778 return len;
2779}
2780
2781static struct md_sysfs_entry bitmap_timeout =
2782__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2783
2784static ssize_t
2785backlog_show(struct mddev *mddev, char *page)
2786{
2787 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2788}
2789
2790static ssize_t
2791backlog_store(struct mddev *mddev, const char *buf, size_t len)
2792{
2793 unsigned long backlog;
2794 unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
2795 struct md_rdev *rdev;
2796 bool has_write_mostly = false;
2797 int rv = kstrtoul(buf, 10, &backlog);
2798 if (rv)
2799 return rv;
2800 if (backlog > COUNTER_MAX)
2801 return -EINVAL;
2802
2803 rv = mddev_suspend_and_lock(mddev);
2804 if (rv)
2805 return rv;
2806
2807 /*
2808 * Without write mostly device, it doesn't make sense to set
2809 * backlog for max_write_behind.
2810 */
2811 rdev_for_each(rdev, mddev) {
2812 if (test_bit(WriteMostly, &rdev->flags)) {
2813 has_write_mostly = true;
2814 break;
2815 }
2816 }
2817 if (!has_write_mostly) {
2818 pr_warn_ratelimited("%s: can't set backlog, no write mostly device available\n",
2819 mdname(mddev));
2820 mddev_unlock(mddev);
2821 return -EINVAL;
2822 }
2823
2824 mddev->bitmap_info.max_write_behind = backlog;
2825 if (!backlog && mddev->serial_info_pool) {
2826 /* serial_info_pool is not needed if backlog is zero */
2827 if (!mddev->serialize_policy)
2828 mddev_destroy_serial_pool(mddev, NULL);
2829 } else if (backlog && !mddev->serial_info_pool) {
2830 /* serial_info_pool is needed since backlog is not zero */
2831 rdev_for_each(rdev, mddev)
2832 mddev_create_serial_pool(mddev, rdev);
2833 }
2834 if (old_mwb != backlog)
2835 bitmap_update_sb(mddev->bitmap);
2836
2837 mddev_unlock_and_resume(mddev);
2838 return len;
2839}
2840
2841static struct md_sysfs_entry bitmap_backlog =
2842__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2843
2844static ssize_t
2845chunksize_show(struct mddev *mddev, char *page)
2846{
2847 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2848}
2849
2850static ssize_t
2851chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2852{
2853 /* Can only be changed when no bitmap is active */
2854 int rv;
2855 unsigned long csize;
2856 if (mddev->bitmap)
2857 return -EBUSY;
2858 rv = kstrtoul(buf, 10, &csize);
2859 if (rv)
2860 return rv;
2861 if (csize < 512 ||
2862 !is_power_of_2(csize))
2863 return -EINVAL;
2864 if (BITS_PER_LONG > 32 && csize >= (1ULL << (BITS_PER_BYTE *
2865 sizeof(((bitmap_super_t *)0)->chunksize))))
2866 return -EOVERFLOW;
2867 mddev->bitmap_info.chunksize = csize;
2868 return len;
2869}
2870
2871static struct md_sysfs_entry bitmap_chunksize =
2872__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2873
2874static ssize_t metadata_show(struct mddev *mddev, char *page)
2875{
2876 if (mddev_is_clustered(mddev))
2877 return sprintf(page, "clustered\n");
2878 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2879 ? "external" : "internal"));
2880}
2881
2882static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2883{
2884 if (mddev->bitmap ||
2885 mddev->bitmap_info.file ||
2886 mddev->bitmap_info.offset)
2887 return -EBUSY;
2888 if (strncmp(buf, "external", 8) == 0)
2889 mddev->bitmap_info.external = 1;
2890 else if ((strncmp(buf, "internal", 8) == 0) ||
2891 (strncmp(buf, "clustered", 9) == 0))
2892 mddev->bitmap_info.external = 0;
2893 else
2894 return -EINVAL;
2895 return len;
2896}
2897
2898static struct md_sysfs_entry bitmap_metadata =
2899__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2900
2901static ssize_t can_clear_show(struct mddev *mddev, char *page)
2902{
2903 int len;
2904 struct bitmap *bitmap;
2905
2906 spin_lock(&mddev->lock);
2907 bitmap = mddev->bitmap;
2908 if (bitmap)
2909 len = sprintf(page, "%s\n", (bitmap->need_sync ? "false" :
2910 "true"));
2911 else
2912 len = sprintf(page, "\n");
2913 spin_unlock(&mddev->lock);
2914 return len;
2915}
2916
2917static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2918{
2919 struct bitmap *bitmap = mddev->bitmap;
2920
2921 if (!bitmap)
2922 return -ENOENT;
2923
2924 if (strncmp(buf, "false", 5) == 0) {
2925 bitmap->need_sync = 1;
2926 return len;
2927 }
2928
2929 if (strncmp(buf, "true", 4) == 0) {
2930 if (mddev->degraded)
2931 return -EBUSY;
2932 bitmap->need_sync = 0;
2933 return len;
2934 }
2935
2936 return -EINVAL;
2937}
2938
2939static struct md_sysfs_entry bitmap_can_clear =
2940__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2941
2942static ssize_t
2943behind_writes_used_show(struct mddev *mddev, char *page)
2944{
2945 ssize_t ret;
2946 struct bitmap *bitmap;
2947
2948 spin_lock(&mddev->lock);
2949 bitmap = mddev->bitmap;
2950 if (!bitmap)
2951 ret = sprintf(page, "0\n");
2952 else
2953 ret = sprintf(page, "%lu\n", bitmap->behind_writes_used);
2954 spin_unlock(&mddev->lock);
2955
2956 return ret;
2957}
2958
2959static ssize_t
2960behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2961{
2962 struct bitmap *bitmap = mddev->bitmap;
2963
2964 if (bitmap)
2965 bitmap->behind_writes_used = 0;
2966 return len;
2967}
2968
2969static struct md_sysfs_entry max_backlog_used =
2970__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2971 behind_writes_used_show, behind_writes_used_reset);
2972
2973static struct attribute *md_bitmap_attrs[] = {
2974 &bitmap_location.attr,
2975 &bitmap_space.attr,
2976 &bitmap_timeout.attr,
2977 &bitmap_backlog.attr,
2978 &bitmap_chunksize.attr,
2979 &bitmap_metadata.attr,
2980 &bitmap_can_clear.attr,
2981 &max_backlog_used.attr,
2982 NULL
2983};
2984const struct attribute_group md_bitmap_group = {
2985 .name = "bitmap",
2986 .attrs = md_bitmap_attrs,
2987};
2988
2989static struct bitmap_operations bitmap_ops = {
2990 .enabled = bitmap_enabled,
2991 .create = bitmap_create,
2992 .resize = bitmap_resize,
2993 .load = bitmap_load,
2994 .destroy = bitmap_destroy,
2995 .flush = bitmap_flush,
2996 .write_all = bitmap_write_all,
2997 .dirty_bits = bitmap_dirty_bits,
2998 .unplug = bitmap_unplug,
2999 .daemon_work = bitmap_daemon_work,
3000
3001 .start_behind_write = bitmap_start_behind_write,
3002 .end_behind_write = bitmap_end_behind_write,
3003 .wait_behind_writes = bitmap_wait_behind_writes,
3004
3005 .startwrite = bitmap_startwrite,
3006 .endwrite = bitmap_endwrite,
3007 .start_sync = bitmap_start_sync,
3008 .end_sync = bitmap_end_sync,
3009 .cond_end_sync = bitmap_cond_end_sync,
3010 .close_sync = bitmap_close_sync,
3011
3012 .update_sb = bitmap_update_sb,
3013 .get_stats = bitmap_get_stats,
3014
3015 .sync_with_cluster = bitmap_sync_with_cluster,
3016 .get_from_slot = bitmap_get_from_slot,
3017 .copy_from_slot = bitmap_copy_from_slot,
3018 .set_pages = bitmap_set_pages,
3019 .free = md_bitmap_free,
3020};
3021
3022void mddev_set_bitmap_ops(struct mddev *mddev)
3023{
3024 mddev->bitmap_ops = &bitmap_ops;
3025}