projects/linux·blob v3.2 · refs

2117 lines · 55.1 KiB

1/*
2 * bitmap.c two-level bitmap (C) Peter T. Breuer ([email protected]) 2003
3 *
4 * bitmap_create - sets up the bitmap structure
5 * bitmap_destroy - destroys the bitmap structure
6 *
7 * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
8 * - added disk storage for bitmap
9 * - changes to allow various bitmap chunk sizes
10 */
11
12/*
13 * Still to do:
14 *
15 * flush after percent set rather than just time based. (maybe both).
16 */
17
18#include <linux/blkdev.h>
19#include <linux/module.h>
20#include <linux/errno.h>
21#include <linux/slab.h>
22#include <linux/init.h>
23#include <linux/timer.h>
24#include <linux/sched.h>
25#include <linux/list.h>
26#include <linux/file.h>
27#include <linux/mount.h>
28#include <linux/buffer_head.h>
29#include "md.h"
30#include "bitmap.h"
31
32static inline char *bmname(struct bitmap *bitmap)
33{
34 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
35}
36
37/*
38 * just a placeholder - calls kmalloc for bitmap pages
39 */
40static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
41{
42 unsigned char *page;
43
44 page = kzalloc(PAGE_SIZE, GFP_NOIO);
45 if (!page)
46 printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
47 else
48 pr_debug("%s: bitmap_alloc_page: allocated page at %p\n",
49 bmname(bitmap), page);
50 return page;
51}
52
53/*
54 * for now just a placeholder -- just calls kfree for bitmap pages
55 */
56static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
57{
58 pr_debug("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
59 kfree(page);
60}
61
62/*
63 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
64 *
65 * 1) check to see if this page is allocated, if it's not then try to alloc
66 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
67 * page pointer directly as a counter
68 *
69 * if we find our page, we increment the page's refcount so that it stays
70 * allocated while we're using it
71 */
72static int bitmap_checkpage(struct bitmap *bitmap,
73 unsigned long page, int create)
74__releases(bitmap->lock)
75__acquires(bitmap->lock)
76{
77 unsigned char *mappage;
78
79 if (page >= bitmap->pages) {
80 /* This can happen if bitmap_start_sync goes beyond
81 * End-of-device while looking for a whole page.
82 * It is harmless.
83 */
84 return -EINVAL;
85 }
86
87 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
88 return 0;
89
90 if (bitmap->bp[page].map) /* page is already allocated, just return */
91 return 0;
92
93 if (!create)
94 return -ENOENT;
95
96 /* this page has not been allocated yet */
97
98 spin_unlock_irq(&bitmap->lock);
99 mappage = bitmap_alloc_page(bitmap);
100 spin_lock_irq(&bitmap->lock);
101
102 if (mappage == NULL) {
103 pr_debug("%s: bitmap map page allocation failed, hijacking\n",
104 bmname(bitmap));
105 /* failed - set the hijacked flag so that we can use the
106 * pointer as a counter */
107 if (!bitmap->bp[page].map)
108 bitmap->bp[page].hijacked = 1;
109 } else if (bitmap->bp[page].map ||
110 bitmap->bp[page].hijacked) {
111 /* somebody beat us to getting the page */
112 bitmap_free_page(bitmap, mappage);
113 return 0;
114 } else {
115
116 /* no page was in place and we have one, so install it */
117
118 bitmap->bp[page].map = mappage;
119 bitmap->missing_pages--;
120 }
121 return 0;
122}
123
124/* if page is completely empty, put it back on the free list, or dealloc it */
125/* if page was hijacked, unmark the flag so it might get alloced next time */
126/* Note: lock should be held when calling this */
127static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
128{
129 char *ptr;
130
131 if (bitmap->bp[page].count) /* page is still busy */
132 return;
133
134 /* page is no longer in use, it can be released */
135
136 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
137 bitmap->bp[page].hijacked = 0;
138 bitmap->bp[page].map = NULL;
139 } else {
140 /* normal case, free the page */
141 ptr = bitmap->bp[page].map;
142 bitmap->bp[page].map = NULL;
143 bitmap->missing_pages++;
144 bitmap_free_page(bitmap, ptr);
145 }
146}
147
148/*
149 * bitmap file handling - read and write the bitmap file and its superblock
150 */
151
152/*
153 * basic page I/O operations
154 */
155
156/* IO operations when bitmap is stored near all superblocks */
157static struct page *read_sb_page(struct mddev *mddev, loff_t offset,
158 struct page *page,
159 unsigned long index, int size)
160{
161 /* choose a good rdev and read the page from there */
162
163 struct md_rdev *rdev;
164 sector_t target;
165 int did_alloc = 0;
166
167 if (!page) {
168 page = alloc_page(GFP_KERNEL);
169 if (!page)
170 return ERR_PTR(-ENOMEM);
171 did_alloc = 1;
172 }
173
174 list_for_each_entry(rdev, &mddev->disks, same_set) {
175 if (! test_bit(In_sync, &rdev->flags)
176 || test_bit(Faulty, &rdev->flags))
177 continue;
178
179 target = offset + index * (PAGE_SIZE/512);
180
181 if (sync_page_io(rdev, target,
182 roundup(size, bdev_logical_block_size(rdev->bdev)),
183 page, READ, true)) {
184 page->index = index;
185 attach_page_buffers(page, NULL); /* so that free_buffer will
186 * quietly no-op */
187 return page;
188 }
189 }
190 if (did_alloc)
191 put_page(page);
192 return ERR_PTR(-EIO);
193
194}
195
196static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
197{
198 /* Iterate the disks of an mddev, using rcu to protect access to the
199 * linked list, and raising the refcount of devices we return to ensure
200 * they don't disappear while in use.
201 * As devices are only added or removed when raid_disk is < 0 and
202 * nr_pending is 0 and In_sync is clear, the entries we return will
203 * still be in the same position on the list when we re-enter
204 * list_for_each_continue_rcu.
205 */
206 struct list_head *pos;
207 rcu_read_lock();
208 if (rdev == NULL)
209 /* start at the beginning */
210 pos = &mddev->disks;
211 else {
212 /* release the previous rdev and start from there. */
213 rdev_dec_pending(rdev, mddev);
214 pos = &rdev->same_set;
215 }
216 list_for_each_continue_rcu(pos, &mddev->disks) {
217 rdev = list_entry(pos, struct md_rdev, same_set);
218 if (rdev->raid_disk >= 0 &&
219 !test_bit(Faulty, &rdev->flags)) {
220 /* this is a usable devices */
221 atomic_inc(&rdev->nr_pending);
222 rcu_read_unlock();
223 return rdev;
224 }
225 }
226 rcu_read_unlock();
227 return NULL;
228}
229
230static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
231{
232 struct md_rdev *rdev = NULL;
233 struct block_device *bdev;
234 struct mddev *mddev = bitmap->mddev;
235
236 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
237 int size = PAGE_SIZE;
238 loff_t offset = mddev->bitmap_info.offset;
239
240 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
241
242 if (page->index == bitmap->file_pages-1)
243 size = roundup(bitmap->last_page_size,
244 bdev_logical_block_size(bdev));
245 /* Just make sure we aren't corrupting data or
246 * metadata
247 */
248 if (mddev->external) {
249 /* Bitmap could be anywhere. */
250 if (rdev->sb_start + offset + (page->index
251 * (PAGE_SIZE/512))
252 > rdev->data_offset
253 &&
254 rdev->sb_start + offset
255 < (rdev->data_offset + mddev->dev_sectors
256 + (PAGE_SIZE/512)))
257 goto bad_alignment;
258 } else if (offset < 0) {
259 /* DATA BITMAP METADATA */
260 if (offset
261 + (long)(page->index * (PAGE_SIZE/512))
262 + size/512 > 0)
263 /* bitmap runs in to metadata */
264 goto bad_alignment;
265 if (rdev->data_offset + mddev->dev_sectors
266 > rdev->sb_start + offset)
267 /* data runs in to bitmap */
268 goto bad_alignment;
269 } else if (rdev->sb_start < rdev->data_offset) {
270 /* METADATA BITMAP DATA */
271 if (rdev->sb_start
272 + offset
273 + page->index*(PAGE_SIZE/512) + size/512
274 > rdev->data_offset)
275 /* bitmap runs in to data */
276 goto bad_alignment;
277 } else {
278 /* DATA METADATA BITMAP - no problems */
279 }
280 md_super_write(mddev, rdev,
281 rdev->sb_start + offset
282 + page->index * (PAGE_SIZE/512),
283 size,
284 page);
285 }
286
287 if (wait)
288 md_super_wait(mddev);
289 return 0;
290
291 bad_alignment:
292 return -EINVAL;
293}
294
295static void bitmap_file_kick(struct bitmap *bitmap);
296/*
297 * write out a page to a file
298 */
299static void write_page(struct bitmap *bitmap, struct page *page, int wait)
300{
301 struct buffer_head *bh;
302
303 if (bitmap->file == NULL) {
304 switch (write_sb_page(bitmap, page, wait)) {
305 case -EINVAL:
306 bitmap->flags |= BITMAP_WRITE_ERROR;
307 }
308 } else {
309
310 bh = page_buffers(page);
311
312 while (bh && bh->b_blocknr) {
313 atomic_inc(&bitmap->pending_writes);
314 set_buffer_locked(bh);
315 set_buffer_mapped(bh);
316 submit_bh(WRITE | REQ_SYNC, bh);
317 bh = bh->b_this_page;
318 }
319
320 if (wait)
321 wait_event(bitmap->write_wait,
322 atomic_read(&bitmap->pending_writes)==0);
323 }
324 if (bitmap->flags & BITMAP_WRITE_ERROR)
325 bitmap_file_kick(bitmap);
326}
327
328static void end_bitmap_write(struct buffer_head *bh, int uptodate)
329{
330 struct bitmap *bitmap = bh->b_private;
331 unsigned long flags;
332
333 if (!uptodate) {
334 spin_lock_irqsave(&bitmap->lock, flags);
335 bitmap->flags |= BITMAP_WRITE_ERROR;
336 spin_unlock_irqrestore(&bitmap->lock, flags);
337 }
338 if (atomic_dec_and_test(&bitmap->pending_writes))
339 wake_up(&bitmap->write_wait);
340}
341
342/* copied from buffer.c */
343static void
344__clear_page_buffers(struct page *page)
345{
346 ClearPagePrivate(page);
347 set_page_private(page, 0);
348 page_cache_release(page);
349}
350static void free_buffers(struct page *page)
351{
352 struct buffer_head *bh = page_buffers(page);
353
354 while (bh) {
355 struct buffer_head *next = bh->b_this_page;
356 free_buffer_head(bh);
357 bh = next;
358 }
359 __clear_page_buffers(page);
360 put_page(page);
361}
362
363/* read a page from a file.
364 * We both read the page, and attach buffers to the page to record the
365 * address of each block (using bmap). These addresses will be used
366 * to write the block later, completely bypassing the filesystem.
367 * This usage is similar to how swap files are handled, and allows us
368 * to write to a file with no concerns of memory allocation failing.
369 */
370static struct page *read_page(struct file *file, unsigned long index,
371 struct bitmap *bitmap,
372 unsigned long count)
373{
374 struct page *page = NULL;
375 struct inode *inode = file->f_path.dentry->d_inode;
376 struct buffer_head *bh;
377 sector_t block;
378
379 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
380 (unsigned long long)index << PAGE_SHIFT);
381
382 page = alloc_page(GFP_KERNEL);
383 if (!page)
384 page = ERR_PTR(-ENOMEM);
385 if (IS_ERR(page))
386 goto out;
387
388 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
389 if (!bh) {
390 put_page(page);
391 page = ERR_PTR(-ENOMEM);
392 goto out;
393 }
394 attach_page_buffers(page, bh);
395 block = index << (PAGE_SHIFT - inode->i_blkbits);
396 while (bh) {
397 if (count == 0)
398 bh->b_blocknr = 0;
399 else {
400 bh->b_blocknr = bmap(inode, block);
401 if (bh->b_blocknr == 0) {
402 /* Cannot use this file! */
403 free_buffers(page);
404 page = ERR_PTR(-EINVAL);
405 goto out;
406 }
407 bh->b_bdev = inode->i_sb->s_bdev;
408 if (count < (1<<inode->i_blkbits))
409 count = 0;
410 else
411 count -= (1<<inode->i_blkbits);
412
413 bh->b_end_io = end_bitmap_write;
414 bh->b_private = bitmap;
415 atomic_inc(&bitmap->pending_writes);
416 set_buffer_locked(bh);
417 set_buffer_mapped(bh);
418 submit_bh(READ, bh);
419 }
420 block++;
421 bh = bh->b_this_page;
422 }
423 page->index = index;
424
425 wait_event(bitmap->write_wait,
426 atomic_read(&bitmap->pending_writes)==0);
427 if (bitmap->flags & BITMAP_WRITE_ERROR) {
428 free_buffers(page);
429 page = ERR_PTR(-EIO);
430 }
431out:
432 if (IS_ERR(page))
433 printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %ld\n",
434 (int)PAGE_SIZE,
435 (unsigned long long)index << PAGE_SHIFT,
436 PTR_ERR(page));
437 return page;
438}
439
440/*
441 * bitmap file superblock operations
442 */
443
444/* update the event counter and sync the superblock to disk */
445void bitmap_update_sb(struct bitmap *bitmap)
446{
447 bitmap_super_t *sb;
448 unsigned long flags;
449
450 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
451 return;
452 if (bitmap->mddev->bitmap_info.external)
453 return;
454 spin_lock_irqsave(&bitmap->lock, flags);
455 if (!bitmap->sb_page) { /* no superblock */
456 spin_unlock_irqrestore(&bitmap->lock, flags);
457 return;
458 }
459 spin_unlock_irqrestore(&bitmap->lock, flags);
460 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
461 sb->events = cpu_to_le64(bitmap->mddev->events);
462 if (bitmap->mddev->events < bitmap->events_cleared)
463 /* rocking back to read-only */
464 bitmap->events_cleared = bitmap->mddev->events;
465 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
466 sb->state = cpu_to_le32(bitmap->flags);
467 /* Just in case these have been changed via sysfs: */
468 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
469 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
470 kunmap_atomic(sb, KM_USER0);
471 write_page(bitmap, bitmap->sb_page, 1);
472}
473
474/* print out the bitmap file superblock */
475void bitmap_print_sb(struct bitmap *bitmap)
476{
477 bitmap_super_t *sb;
478
479 if (!bitmap || !bitmap->sb_page)
480 return;
481 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
482 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
483 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
484 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
485 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
486 *(__u32 *)(sb->uuid+0),
487 *(__u32 *)(sb->uuid+4),
488 *(__u32 *)(sb->uuid+8),
489 *(__u32 *)(sb->uuid+12));
490 printk(KERN_DEBUG " events: %llu\n",
491 (unsigned long long) le64_to_cpu(sb->events));
492 printk(KERN_DEBUG "events cleared: %llu\n",
493 (unsigned long long) le64_to_cpu(sb->events_cleared));
494 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
495 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
496 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
497 printk(KERN_DEBUG " sync size: %llu KB\n",
498 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
499 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
500 kunmap_atomic(sb, KM_USER0);
501}
502
503/*
504 * bitmap_new_disk_sb
505 * @bitmap
506 *
507 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
508 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
509 * This function verifies 'bitmap_info' and populates the on-disk bitmap
510 * structure, which is to be written to disk.
511 *
512 * Returns: 0 on success, -Exxx on error
513 */
514static int bitmap_new_disk_sb(struct bitmap *bitmap)
515{
516 bitmap_super_t *sb;
517 unsigned long chunksize, daemon_sleep, write_behind;
518 int err = -EINVAL;
519
520 bitmap->sb_page = alloc_page(GFP_KERNEL);
521 if (IS_ERR(bitmap->sb_page)) {
522 err = PTR_ERR(bitmap->sb_page);
523 bitmap->sb_page = NULL;
524 return err;
525 }
526 bitmap->sb_page->index = 0;
527
528 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
529
530 sb->magic = cpu_to_le32(BITMAP_MAGIC);
531 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
532
533 chunksize = bitmap->mddev->bitmap_info.chunksize;
534 BUG_ON(!chunksize);
535 if (!is_power_of_2(chunksize)) {
536 kunmap_atomic(sb, KM_USER0);
537 printk(KERN_ERR "bitmap chunksize not a power of 2\n");
538 return -EINVAL;
539 }
540 sb->chunksize = cpu_to_le32(chunksize);
541
542 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
543 if (!daemon_sleep ||
544 (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
545 printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
546 daemon_sleep = 5 * HZ;
547 }
548 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
549 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
550
551 /*
552 * FIXME: write_behind for RAID1. If not specified, what
553 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
554 */
555 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
556 if (write_behind > COUNTER_MAX)
557 write_behind = COUNTER_MAX / 2;
558 sb->write_behind = cpu_to_le32(write_behind);
559 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
560
561 /* keep the array size field of the bitmap superblock up to date */
562 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
563
564 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
565
566 bitmap->flags |= BITMAP_STALE;
567 sb->state |= cpu_to_le32(BITMAP_STALE);
568 bitmap->events_cleared = bitmap->mddev->events;
569 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
570
571 bitmap->flags |= BITMAP_HOSTENDIAN;
572 sb->version = cpu_to_le32(BITMAP_MAJOR_HOSTENDIAN);
573
574 kunmap_atomic(sb, KM_USER0);
575
576 return 0;
577}
578
579/* read the superblock from the bitmap file and initialize some bitmap fields */
580static int bitmap_read_sb(struct bitmap *bitmap)
581{
582 char *reason = NULL;
583 bitmap_super_t *sb;
584 unsigned long chunksize, daemon_sleep, write_behind;
585 unsigned long long events;
586 int err = -EINVAL;
587
588 /* page 0 is the superblock, read it... */
589 if (bitmap->file) {
590 loff_t isize = i_size_read(bitmap->file->f_mapping->host);
591 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
592
593 bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
594 } else {
595 bitmap->sb_page = read_sb_page(bitmap->mddev,
596 bitmap->mddev->bitmap_info.offset,
597 NULL,
598 0, sizeof(bitmap_super_t));
599 }
600 if (IS_ERR(bitmap->sb_page)) {
601 err = PTR_ERR(bitmap->sb_page);
602 bitmap->sb_page = NULL;
603 return err;
604 }
605
606 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
607
608 chunksize = le32_to_cpu(sb->chunksize);
609 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
610 write_behind = le32_to_cpu(sb->write_behind);
611
612 /* verify that the bitmap-specific fields are valid */
613 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
614 reason = "bad magic";
615 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
616 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
617 reason = "unrecognized superblock version";
618 else if (chunksize < 512)
619 reason = "bitmap chunksize too small";
620 else if (!is_power_of_2(chunksize))
621 reason = "bitmap chunksize not a power of 2";
622 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
623 reason = "daemon sleep period out of range";
624 else if (write_behind > COUNTER_MAX)
625 reason = "write-behind limit out of range (0 - 16383)";
626 if (reason) {
627 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
628 bmname(bitmap), reason);
629 goto out;
630 }
631
632 /* keep the array size field of the bitmap superblock up to date */
633 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
634
635 if (!bitmap->mddev->persistent)
636 goto success;
637
638 /*
639 * if we have a persistent array superblock, compare the
640 * bitmap's UUID and event counter to the mddev's
641 */
642 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
643 printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
644 bmname(bitmap));
645 goto out;
646 }
647 events = le64_to_cpu(sb->events);
648 if (events < bitmap->mddev->events) {
649 printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
650 "-- forcing full recovery\n", bmname(bitmap), events,
651 (unsigned long long) bitmap->mddev->events);
652 sb->state |= cpu_to_le32(BITMAP_STALE);
653 }
654success:
655 /* assign fields using values from superblock */
656 bitmap->mddev->bitmap_info.chunksize = chunksize;
657 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
658 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
659 bitmap->flags |= le32_to_cpu(sb->state);
660 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
661 bitmap->flags |= BITMAP_HOSTENDIAN;
662 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
663 if (bitmap->flags & BITMAP_STALE)
664 bitmap->events_cleared = bitmap->mddev->events;
665 err = 0;
666out:
667 kunmap_atomic(sb, KM_USER0);
668 if (err)
669 bitmap_print_sb(bitmap);
670 return err;
671}
672
673enum bitmap_mask_op {
674 MASK_SET,
675 MASK_UNSET
676};
677
678/* record the state of the bitmap in the superblock. Return the old value */
679static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
680 enum bitmap_mask_op op)
681{
682 bitmap_super_t *sb;
683 unsigned long flags;
684 int old;
685
686 spin_lock_irqsave(&bitmap->lock, flags);
687 if (!bitmap->sb_page) { /* can't set the state */
688 spin_unlock_irqrestore(&bitmap->lock, flags);
689 return 0;
690 }
691 spin_unlock_irqrestore(&bitmap->lock, flags);
692 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
693 old = le32_to_cpu(sb->state) & bits;
694 switch (op) {
695 case MASK_SET:
696 sb->state |= cpu_to_le32(bits);
697 bitmap->flags |= bits;
698 break;
699 case MASK_UNSET:
700 sb->state &= cpu_to_le32(~bits);
701 bitmap->flags &= ~bits;
702 break;
703 default:
704 BUG();
705 }
706 kunmap_atomic(sb, KM_USER0);
707 return old;
708}
709
710/*
711 * general bitmap file operations
712 */
713
714/*
715 * on-disk bitmap:
716 *
717 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
718 * file a page at a time. There's a superblock at the start of the file.
719 */
720/* calculate the index of the page that contains this bit */
721static inline unsigned long file_page_index(struct bitmap *bitmap, unsigned long chunk)
722{
723 if (!bitmap->mddev->bitmap_info.external)
724 chunk += sizeof(bitmap_super_t) << 3;
725 return chunk >> PAGE_BIT_SHIFT;
726}
727
728/* calculate the (bit) offset of this bit within a page */
729static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned long chunk)
730{
731 if (!bitmap->mddev->bitmap_info.external)
732 chunk += sizeof(bitmap_super_t) << 3;
733 return chunk & (PAGE_BITS - 1);
734}
735
736/*
737 * return a pointer to the page in the filemap that contains the given bit
738 *
739 * this lookup is complicated by the fact that the bitmap sb might be exactly
740 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
741 * 0 or page 1
742 */
743static inline struct page *filemap_get_page(struct bitmap *bitmap,
744 unsigned long chunk)
745{
746 if (file_page_index(bitmap, chunk) >= bitmap->file_pages)
747 return NULL;
748 return bitmap->filemap[file_page_index(bitmap, chunk)
749 - file_page_index(bitmap, 0)];
750}
751
752static void bitmap_file_unmap(struct bitmap *bitmap)
753{
754 struct page **map, *sb_page;
755 unsigned long *attr;
756 int pages;
757 unsigned long flags;
758
759 spin_lock_irqsave(&bitmap->lock, flags);
760 map = bitmap->filemap;
761 bitmap->filemap = NULL;
762 attr = bitmap->filemap_attr;
763 bitmap->filemap_attr = NULL;
764 pages = bitmap->file_pages;
765 bitmap->file_pages = 0;
766 sb_page = bitmap->sb_page;
767 bitmap->sb_page = NULL;
768 spin_unlock_irqrestore(&bitmap->lock, flags);
769
770 while (pages--)
771 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
772 free_buffers(map[pages]);
773 kfree(map);
774 kfree(attr);
775
776 if (sb_page)
777 free_buffers(sb_page);
778}
779
780static void bitmap_file_put(struct bitmap *bitmap)
781{
782 struct file *file;
783 unsigned long flags;
784
785 spin_lock_irqsave(&bitmap->lock, flags);
786 file = bitmap->file;
787 bitmap->file = NULL;
788 spin_unlock_irqrestore(&bitmap->lock, flags);
789
790 if (file)
791 wait_event(bitmap->write_wait,
792 atomic_read(&bitmap->pending_writes)==0);
793 bitmap_file_unmap(bitmap);
794
795 if (file) {
796 struct inode *inode = file->f_path.dentry->d_inode;
797 invalidate_mapping_pages(inode->i_mapping, 0, -1);
798 fput(file);
799 }
800}
801
802/*
803 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
804 * then it is no longer reliable, so we stop using it and we mark the file
805 * as failed in the superblock
806 */
807static void bitmap_file_kick(struct bitmap *bitmap)
808{
809 char *path, *ptr = NULL;
810
811 if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
812 bitmap_update_sb(bitmap);
813
814 if (bitmap->file) {
815 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
816 if (path)
817 ptr = d_path(&bitmap->file->f_path, path,
818 PAGE_SIZE);
819
820 printk(KERN_ALERT
821 "%s: kicking failed bitmap file %s from array!\n",
822 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
823
824 kfree(path);
825 } else
826 printk(KERN_ALERT
827 "%s: disabling internal bitmap due to errors\n",
828 bmname(bitmap));
829 }
830
831 bitmap_file_put(bitmap);
832
833 return;
834}
835
836enum bitmap_page_attr {
837 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
838 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
839 * i.e. counter is 1 or 2. */
840 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
841};
842
843static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
844 enum bitmap_page_attr attr)
845{
846 __set_bit((page->index<<2) + attr, bitmap->filemap_attr);
847}
848
849static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
850 enum bitmap_page_attr attr)
851{
852 __clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
853}
854
855static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
856 enum bitmap_page_attr attr)
857{
858 return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
859}
860
861/*
862 * bitmap_file_set_bit -- called before performing a write to the md device
863 * to set (and eventually sync) a particular bit in the bitmap file
864 *
865 * we set the bit immediately, then we record the page number so that
866 * when an unplug occurs, we can flush the dirty pages out to disk
867 */
868static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
869{
870 unsigned long bit;
871 struct page *page;
872 void *kaddr;
873 unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
874
875 if (!bitmap->filemap)
876 return;
877
878 page = filemap_get_page(bitmap, chunk);
879 if (!page)
880 return;
881 bit = file_page_offset(bitmap, chunk);
882
883 /* set the bit */
884 kaddr = kmap_atomic(page, KM_USER0);
885 if (bitmap->flags & BITMAP_HOSTENDIAN)
886 set_bit(bit, kaddr);
887 else
888 __set_bit_le(bit, kaddr);
889 kunmap_atomic(kaddr, KM_USER0);
890 pr_debug("set file bit %lu page %lu\n", bit, page->index);
891 /* record page number so it gets flushed to disk when unplug occurs */
892 set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
893}
894
895/* this gets called when the md device is ready to unplug its underlying
896 * (slave) device queues -- before we let any writes go down, we need to
897 * sync the dirty pages of the bitmap file to disk */
898void bitmap_unplug(struct bitmap *bitmap)
899{
900 unsigned long i, flags;
901 int dirty, need_write;
902 struct page *page;
903 int wait = 0;
904
905 if (!bitmap)
906 return;
907
908 /* look at each page to see if there are any set bits that need to be
909 * flushed out to disk */
910 for (i = 0; i < bitmap->file_pages; i++) {
911 spin_lock_irqsave(&bitmap->lock, flags);
912 if (!bitmap->filemap) {
913 spin_unlock_irqrestore(&bitmap->lock, flags);
914 return;
915 }
916 page = bitmap->filemap[i];
917 dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
918 need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
919 clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
920 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
921 if (dirty)
922 wait = 1;
923 spin_unlock_irqrestore(&bitmap->lock, flags);
924
925 if (dirty || need_write)
926 write_page(bitmap, page, 0);
927 }
928 if (wait) { /* if any writes were performed, we need to wait on them */
929 if (bitmap->file)
930 wait_event(bitmap->write_wait,
931 atomic_read(&bitmap->pending_writes)==0);
932 else
933 md_super_wait(bitmap->mddev);
934 }
935 if (bitmap->flags & BITMAP_WRITE_ERROR)
936 bitmap_file_kick(bitmap);
937}
938EXPORT_SYMBOL(bitmap_unplug);
939
940static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
941/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
942 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
943 * memory mapping of the bitmap file
944 * Special cases:
945 * if there's no bitmap file, or if the bitmap file had been
946 * previously kicked from the array, we mark all the bits as
947 * 1's in order to cause a full resync.
948 *
949 * We ignore all bits for sectors that end earlier than 'start'.
950 * This is used when reading an out-of-date bitmap...
951 */
952static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
953{
954 unsigned long i, chunks, index, oldindex, bit;
955 struct page *page = NULL, *oldpage = NULL;
956 unsigned long num_pages, bit_cnt = 0;
957 struct file *file;
958 unsigned long bytes, offset;
959 int outofdate;
960 int ret = -ENOSPC;
961 void *paddr;
962
963 chunks = bitmap->chunks;
964 file = bitmap->file;
965
966 BUG_ON(!file && !bitmap->mddev->bitmap_info.offset);
967
968 outofdate = bitmap->flags & BITMAP_STALE;
969 if (outofdate)
970 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
971 "recovery\n", bmname(bitmap));
972
973 bytes = DIV_ROUND_UP(bitmap->chunks, 8);
974 if (!bitmap->mddev->bitmap_info.external)
975 bytes += sizeof(bitmap_super_t);
976
977 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
978
979 if (file && i_size_read(file->f_mapping->host) < bytes) {
980 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
981 bmname(bitmap),
982 (unsigned long) i_size_read(file->f_mapping->host),
983 bytes);
984 goto err;
985 }
986
987 ret = -ENOMEM;
988
989 bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
990 if (!bitmap->filemap)
991 goto err;
992
993 /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
994 bitmap->filemap_attr = kzalloc(
995 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
996 GFP_KERNEL);
997 if (!bitmap->filemap_attr)
998 goto err;
999
1000 oldindex = ~0L;
1001
1002 for (i = 0; i < chunks; i++) {
1003 int b;
1004 index = file_page_index(bitmap, i);
1005 bit = file_page_offset(bitmap, i);
1006 if (index != oldindex) { /* this is a new page, read it in */
1007 int count;
1008 /* unmap the old page, we're done with it */
1009 if (index == num_pages-1)
1010 count = bytes - index * PAGE_SIZE;
1011 else
1012 count = PAGE_SIZE;
1013 if (index == 0 && bitmap->sb_page) {
1014 /*
1015 * if we're here then the superblock page
1016 * contains some bits (PAGE_SIZE != sizeof sb)
1017 * we've already read it in, so just use it
1018 */
1019 page = bitmap->sb_page;
1020 offset = sizeof(bitmap_super_t);
1021 if (!file)
1022 page = read_sb_page(
1023 bitmap->mddev,
1024 bitmap->mddev->bitmap_info.offset,
1025 page,
1026 index, count);
1027 } else if (file) {
1028 page = read_page(file, index, bitmap, count);
1029 offset = 0;
1030 } else {
1031 page = read_sb_page(bitmap->mddev,
1032 bitmap->mddev->bitmap_info.offset,
1033 NULL,
1034 index, count);
1035 offset = 0;
1036 }
1037 if (IS_ERR(page)) { /* read error */
1038 ret = PTR_ERR(page);
1039 goto err;
1040 }
1041
1042 oldindex = index;
1043 oldpage = page;
1044
1045 bitmap->filemap[bitmap->file_pages++] = page;
1046 bitmap->last_page_size = count;
1047
1048 if (outofdate) {
1049 /*
1050 * if bitmap is out of date, dirty the
1051 * whole page and write it out
1052 */
1053 paddr = kmap_atomic(page, KM_USER0);
1054 memset(paddr + offset, 0xff,
1055 PAGE_SIZE - offset);
1056 kunmap_atomic(paddr, KM_USER0);
1057 write_page(bitmap, page, 1);
1058
1059 ret = -EIO;
1060 if (bitmap->flags & BITMAP_WRITE_ERROR)
1061 goto err;
1062 }
1063 }
1064 paddr = kmap_atomic(page, KM_USER0);
1065 if (bitmap->flags & BITMAP_HOSTENDIAN)
1066 b = test_bit(bit, paddr);
1067 else
1068 b = test_bit_le(bit, paddr);
1069 kunmap_atomic(paddr, KM_USER0);
1070 if (b) {
1071 /* if the disk bit is set, set the memory bit */
1072 int needed = ((sector_t)(i+1) << (CHUNK_BLOCK_SHIFT(bitmap))
1073 >= start);
1074 bitmap_set_memory_bits(bitmap,
1075 (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap),
1076 needed);
1077 bit_cnt++;
1078 }
1079 }
1080
1081 /* everything went OK */
1082 ret = 0;
1083 bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
1084
1085 if (bit_cnt) { /* Kick recovery if any bits were set */
1086 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1087 md_wakeup_thread(bitmap->mddev->thread);
1088 }
1089
1090 printk(KERN_INFO "%s: bitmap initialized from disk: "
1091 "read %lu/%lu pages, set %lu of %lu bits\n",
1092 bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, chunks);
1093
1094 return 0;
1095
1096 err:
1097 printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1098 bmname(bitmap), ret);
1099 return ret;
1100}
1101
1102void bitmap_write_all(struct bitmap *bitmap)
1103{
1104 /* We don't actually write all bitmap blocks here,
1105 * just flag them as needing to be written
1106 */
1107 int i;
1108
1109 spin_lock_irq(&bitmap->lock);
1110 for (i = 0; i < bitmap->file_pages; i++)
1111 set_page_attr(bitmap, bitmap->filemap[i],
1112 BITMAP_PAGE_NEEDWRITE);
1113 bitmap->allclean = 0;
1114 spin_unlock_irq(&bitmap->lock);
1115}
1116
1117static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
1118{
1119 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1120 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1121 bitmap->bp[page].count += inc;
1122 bitmap_checkfree(bitmap, page);
1123}
1124static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1125 sector_t offset, sector_t *blocks,
1126 int create);
1127
1128/*
1129 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1130 * out to disk
1131 */
1132
1133void bitmap_daemon_work(struct mddev *mddev)
1134{
1135 struct bitmap *bitmap;
1136 unsigned long j;
1137 unsigned long flags;
1138 struct page *page = NULL, *lastpage = NULL;
1139 sector_t blocks;
1140 void *paddr;
1141
1142 /* Use a mutex to guard daemon_work against
1143 * bitmap_destroy.
1144 */
1145 mutex_lock(&mddev->bitmap_info.mutex);
1146 bitmap = mddev->bitmap;
1147 if (bitmap == NULL) {
1148 mutex_unlock(&mddev->bitmap_info.mutex);
1149 return;
1150 }
1151 if (time_before(jiffies, bitmap->daemon_lastrun
1152 + bitmap->mddev->bitmap_info.daemon_sleep))
1153 goto done;
1154
1155 bitmap->daemon_lastrun = jiffies;
1156 if (bitmap->allclean) {
1157 bitmap->mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1158 goto done;
1159 }
1160 bitmap->allclean = 1;
1161
1162 spin_lock_irqsave(&bitmap->lock, flags);
1163 for (j = 0; j < bitmap->chunks; j++) {
1164 bitmap_counter_t *bmc;
1165 if (!bitmap->filemap)
1166 /* error or shutdown */
1167 break;
1168
1169 page = filemap_get_page(bitmap, j);
1170
1171 if (page != lastpage) {
1172 /* skip this page unless it's marked as needing cleaning */
1173 if (!test_page_attr(bitmap, page, BITMAP_PAGE_PENDING)) {
1174 int need_write = test_page_attr(bitmap, page,
1175 BITMAP_PAGE_NEEDWRITE);
1176 if (need_write)
1177 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1178
1179 spin_unlock_irqrestore(&bitmap->lock, flags);
1180 if (need_write)
1181 write_page(bitmap, page, 0);
1182 spin_lock_irqsave(&bitmap->lock, flags);
1183 j |= (PAGE_BITS - 1);
1184 continue;
1185 }
1186
1187 /* grab the new page, sync and release the old */
1188 if (lastpage != NULL) {
1189 if (test_page_attr(bitmap, lastpage,
1190 BITMAP_PAGE_NEEDWRITE)) {
1191 clear_page_attr(bitmap, lastpage,
1192 BITMAP_PAGE_NEEDWRITE);
1193 spin_unlock_irqrestore(&bitmap->lock, flags);
1194 write_page(bitmap, lastpage, 0);
1195 } else {
1196 set_page_attr(bitmap, lastpage,
1197 BITMAP_PAGE_NEEDWRITE);
1198 bitmap->allclean = 0;
1199 spin_unlock_irqrestore(&bitmap->lock, flags);
1200 }
1201 } else
1202 spin_unlock_irqrestore(&bitmap->lock, flags);
1203 lastpage = page;
1204
1205 /* We are possibly going to clear some bits, so make
1206 * sure that events_cleared is up-to-date.
1207 */
1208 if (bitmap->need_sync &&
1209 bitmap->mddev->bitmap_info.external == 0) {
1210 bitmap_super_t *sb;
1211 bitmap->need_sync = 0;
1212 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
1213 sb->events_cleared =
1214 cpu_to_le64(bitmap->events_cleared);
1215 kunmap_atomic(sb, KM_USER0);
1216 write_page(bitmap, bitmap->sb_page, 1);
1217 }
1218 spin_lock_irqsave(&bitmap->lock, flags);
1219 if (!bitmap->need_sync)
1220 clear_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
1221 else
1222 bitmap->allclean = 0;
1223 }
1224 bmc = bitmap_get_counter(bitmap,
1225 (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
1226 &blocks, 0);
1227 if (!bmc)
1228 j |= PAGE_COUNTER_MASK;
1229 else if (*bmc) {
1230 if (*bmc == 1 && !bitmap->need_sync) {
1231 /* we can clear the bit */
1232 *bmc = 0;
1233 bitmap_count_page(bitmap,
1234 (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
1235 -1);
1236
1237 /* clear the bit */
1238 paddr = kmap_atomic(page, KM_USER0);
1239 if (bitmap->flags & BITMAP_HOSTENDIAN)
1240 clear_bit(file_page_offset(bitmap, j),
1241 paddr);
1242 else
1243 __clear_bit_le(
1244 file_page_offset(bitmap,
1245 j),
1246 paddr);
1247 kunmap_atomic(paddr, KM_USER0);
1248 } else if (*bmc <= 2) {
1249 *bmc = 1; /* maybe clear the bit next time */
1250 set_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
1251 bitmap->allclean = 0;
1252 }
1253 }
1254 }
1255 spin_unlock_irqrestore(&bitmap->lock, flags);
1256
1257 /* now sync the final page */
1258 if (lastpage != NULL) {
1259 spin_lock_irqsave(&bitmap->lock, flags);
1260 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1261 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1262 spin_unlock_irqrestore(&bitmap->lock, flags);
1263 write_page(bitmap, lastpage, 0);
1264 } else {
1265 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1266 bitmap->allclean = 0;
1267 spin_unlock_irqrestore(&bitmap->lock, flags);
1268 }
1269 }
1270
1271 done:
1272 if (bitmap->allclean == 0)
1273 bitmap->mddev->thread->timeout =
1274 bitmap->mddev->bitmap_info.daemon_sleep;
1275 mutex_unlock(&mddev->bitmap_info.mutex);
1276}
1277
1278static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1279 sector_t offset, sector_t *blocks,
1280 int create)
1281__releases(bitmap->lock)
1282__acquires(bitmap->lock)
1283{
1284 /* If 'create', we might release the lock and reclaim it.
1285 * The lock must have been taken with interrupts enabled.
1286 * If !create, we don't release the lock.
1287 */
1288 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1289 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1290 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1291 sector_t csize;
1292 int err;
1293
1294 err = bitmap_checkpage(bitmap, page, create);
1295
1296 if (bitmap->bp[page].hijacked ||
1297 bitmap->bp[page].map == NULL)
1298 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
1299 PAGE_COUNTER_SHIFT - 1);
1300 else
1301 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1302 *blocks = csize - (offset & (csize - 1));
1303
1304 if (err < 0)
1305 return NULL;
1306
1307 /* now locked ... */
1308
1309 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1310 /* should we use the first or second counter field
1311 * of the hijacked pointer? */
1312 int hi = (pageoff > PAGE_COUNTER_MASK);
1313 return &((bitmap_counter_t *)
1314 &bitmap->bp[page].map)[hi];
1315 } else /* page is allocated */
1316 return (bitmap_counter_t *)
1317 &(bitmap->bp[page].map[pageoff]);
1318}
1319
1320int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1321{
1322 if (!bitmap)
1323 return 0;
1324
1325 if (behind) {
1326 int bw;
1327 atomic_inc(&bitmap->behind_writes);
1328 bw = atomic_read(&bitmap->behind_writes);
1329 if (bw > bitmap->behind_writes_used)
1330 bitmap->behind_writes_used = bw;
1331
1332 pr_debug("inc write-behind count %d/%lu\n",
1333 bw, bitmap->mddev->bitmap_info.max_write_behind);
1334 }
1335
1336 while (sectors) {
1337 sector_t blocks;
1338 bitmap_counter_t *bmc;
1339
1340 spin_lock_irq(&bitmap->lock);
1341 bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1342 if (!bmc) {
1343 spin_unlock_irq(&bitmap->lock);
1344 return 0;
1345 }
1346
1347 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1348 DEFINE_WAIT(__wait);
1349 /* note that it is safe to do the prepare_to_wait
1350 * after the test as long as we do it before dropping
1351 * the spinlock.
1352 */
1353 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1354 TASK_UNINTERRUPTIBLE);
1355 spin_unlock_irq(&bitmap->lock);
1356 io_schedule();
1357 finish_wait(&bitmap->overflow_wait, &__wait);
1358 continue;
1359 }
1360
1361 switch (*bmc) {
1362 case 0:
1363 bitmap_file_set_bit(bitmap, offset);
1364 bitmap_count_page(bitmap, offset, 1);
1365 /* fall through */
1366 case 1:
1367 *bmc = 2;
1368 }
1369
1370 (*bmc)++;
1371
1372 spin_unlock_irq(&bitmap->lock);
1373
1374 offset += blocks;
1375 if (sectors > blocks)
1376 sectors -= blocks;
1377 else
1378 sectors = 0;
1379 }
1380 return 0;
1381}
1382EXPORT_SYMBOL(bitmap_startwrite);
1383
1384void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1385 int success, int behind)
1386{
1387 if (!bitmap)
1388 return;
1389 if (behind) {
1390 if (atomic_dec_and_test(&bitmap->behind_writes))
1391 wake_up(&bitmap->behind_wait);
1392 pr_debug("dec write-behind count %d/%lu\n",
1393 atomic_read(&bitmap->behind_writes),
1394 bitmap->mddev->bitmap_info.max_write_behind);
1395 }
1396
1397 while (sectors) {
1398 sector_t blocks;
1399 unsigned long flags;
1400 bitmap_counter_t *bmc;
1401
1402 spin_lock_irqsave(&bitmap->lock, flags);
1403 bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1404 if (!bmc) {
1405 spin_unlock_irqrestore(&bitmap->lock, flags);
1406 return;
1407 }
1408
1409 if (success && !bitmap->mddev->degraded &&
1410 bitmap->events_cleared < bitmap->mddev->events) {
1411 bitmap->events_cleared = bitmap->mddev->events;
1412 bitmap->need_sync = 1;
1413 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1414 }
1415
1416 if (!success && !NEEDED(*bmc))
1417 *bmc |= NEEDED_MASK;
1418
1419 if (COUNTER(*bmc) == COUNTER_MAX)
1420 wake_up(&bitmap->overflow_wait);
1421
1422 (*bmc)--;
1423 if (*bmc <= 2) {
1424 set_page_attr(bitmap,
1425 filemap_get_page(
1426 bitmap,
1427 offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1428 BITMAP_PAGE_PENDING);
1429 bitmap->allclean = 0;
1430 }
1431 spin_unlock_irqrestore(&bitmap->lock, flags);
1432 offset += blocks;
1433 if (sectors > blocks)
1434 sectors -= blocks;
1435 else
1436 sectors = 0;
1437 }
1438}
1439EXPORT_SYMBOL(bitmap_endwrite);
1440
1441static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1442 int degraded)
1443{
1444 bitmap_counter_t *bmc;
1445 int rv;
1446 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1447 *blocks = 1024;
1448 return 1; /* always resync if no bitmap */
1449 }
1450 spin_lock_irq(&bitmap->lock);
1451 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1452 rv = 0;
1453 if (bmc) {
1454 /* locked */
1455 if (RESYNC(*bmc))
1456 rv = 1;
1457 else if (NEEDED(*bmc)) {
1458 rv = 1;
1459 if (!degraded) { /* don't set/clear bits if degraded */
1460 *bmc |= RESYNC_MASK;
1461 *bmc &= ~NEEDED_MASK;
1462 }
1463 }
1464 }
1465 spin_unlock_irq(&bitmap->lock);
1466 return rv;
1467}
1468
1469int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1470 int degraded)
1471{
1472 /* bitmap_start_sync must always report on multiples of whole
1473 * pages, otherwise resync (which is very PAGE_SIZE based) will
1474 * get confused.
1475 * So call __bitmap_start_sync repeatedly (if needed) until
1476 * At least PAGE_SIZE>>9 blocks are covered.
1477 * Return the 'or' of the result.
1478 */
1479 int rv = 0;
1480 sector_t blocks1;
1481
1482 *blocks = 0;
1483 while (*blocks < (PAGE_SIZE>>9)) {
1484 rv |= __bitmap_start_sync(bitmap, offset,
1485 &blocks1, degraded);
1486 offset += blocks1;
1487 *blocks += blocks1;
1488 }
1489 return rv;
1490}
1491EXPORT_SYMBOL(bitmap_start_sync);
1492
1493void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1494{
1495 bitmap_counter_t *bmc;
1496 unsigned long flags;
1497
1498 if (bitmap == NULL) {
1499 *blocks = 1024;
1500 return;
1501 }
1502 spin_lock_irqsave(&bitmap->lock, flags);
1503 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1504 if (bmc == NULL)
1505 goto unlock;
1506 /* locked */
1507 if (RESYNC(*bmc)) {
1508 *bmc &= ~RESYNC_MASK;
1509
1510 if (!NEEDED(*bmc) && aborted)
1511 *bmc |= NEEDED_MASK;
1512 else {
1513 if (*bmc <= 2) {
1514 set_page_attr(bitmap,
1515 filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1516 BITMAP_PAGE_PENDING);
1517 bitmap->allclean = 0;
1518 }
1519 }
1520 }
1521 unlock:
1522 spin_unlock_irqrestore(&bitmap->lock, flags);
1523}
1524EXPORT_SYMBOL(bitmap_end_sync);
1525
1526void bitmap_close_sync(struct bitmap *bitmap)
1527{
1528 /* Sync has finished, and any bitmap chunks that weren't synced
1529 * properly have been aborted. It remains to us to clear the
1530 * RESYNC bit wherever it is still on
1531 */
1532 sector_t sector = 0;
1533 sector_t blocks;
1534 if (!bitmap)
1535 return;
1536 while (sector < bitmap->mddev->resync_max_sectors) {
1537 bitmap_end_sync(bitmap, sector, &blocks, 0);
1538 sector += blocks;
1539 }
1540}
1541EXPORT_SYMBOL(bitmap_close_sync);
1542
1543void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
1544{
1545 sector_t s = 0;
1546 sector_t blocks;
1547
1548 if (!bitmap)
1549 return;
1550 if (sector == 0) {
1551 bitmap->last_end_sync = jiffies;
1552 return;
1553 }
1554 if (time_before(jiffies, (bitmap->last_end_sync
1555 + bitmap->mddev->bitmap_info.daemon_sleep)))
1556 return;
1557 wait_event(bitmap->mddev->recovery_wait,
1558 atomic_read(&bitmap->mddev->recovery_active) == 0);
1559
1560 bitmap->mddev->curr_resync_completed = sector;
1561 set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1562 sector &= ~((1ULL << CHUNK_BLOCK_SHIFT(bitmap)) - 1);
1563 s = 0;
1564 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1565 bitmap_end_sync(bitmap, s, &blocks, 0);
1566 s += blocks;
1567 }
1568 bitmap->last_end_sync = jiffies;
1569 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1570}
1571EXPORT_SYMBOL(bitmap_cond_end_sync);
1572
1573static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1574{
1575 /* For each chunk covered by any of these sectors, set the
1576 * counter to 1 and set resync_needed. They should all
1577 * be 0 at this point
1578 */
1579
1580 sector_t secs;
1581 bitmap_counter_t *bmc;
1582 spin_lock_irq(&bitmap->lock);
1583 bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1584 if (!bmc) {
1585 spin_unlock_irq(&bitmap->lock);
1586 return;
1587 }
1588 if (!*bmc) {
1589 struct page *page;
1590 *bmc = 1 | (needed ? NEEDED_MASK : 0);
1591 bitmap_count_page(bitmap, offset, 1);
1592 page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
1593 set_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
1594 bitmap->allclean = 0;
1595 }
1596 spin_unlock_irq(&bitmap->lock);
1597}
1598
1599/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1600void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1601{
1602 unsigned long chunk;
1603
1604 for (chunk = s; chunk <= e; chunk++) {
1605 sector_t sec = (sector_t)chunk << CHUNK_BLOCK_SHIFT(bitmap);
1606 bitmap_set_memory_bits(bitmap, sec, 1);
1607 spin_lock_irq(&bitmap->lock);
1608 bitmap_file_set_bit(bitmap, sec);
1609 spin_unlock_irq(&bitmap->lock);
1610 if (sec < bitmap->mddev->recovery_cp)
1611 /* We are asserting that the array is dirty,
1612 * so move the recovery_cp address back so
1613 * that it is obvious that it is dirty
1614 */
1615 bitmap->mddev->recovery_cp = sec;
1616 }
1617}
1618
1619/*
1620 * flush out any pending updates
1621 */
1622void bitmap_flush(struct mddev *mddev)
1623{
1624 struct bitmap *bitmap = mddev->bitmap;
1625 long sleep;
1626
1627 if (!bitmap) /* there was no bitmap */
1628 return;
1629
1630 /* run the daemon_work three time to ensure everything is flushed
1631 * that can be
1632 */
1633 sleep = mddev->bitmap_info.daemon_sleep * 2;
1634 bitmap->daemon_lastrun -= sleep;
1635 bitmap_daemon_work(mddev);
1636 bitmap->daemon_lastrun -= sleep;
1637 bitmap_daemon_work(mddev);
1638 bitmap->daemon_lastrun -= sleep;
1639 bitmap_daemon_work(mddev);
1640 bitmap_update_sb(bitmap);
1641}
1642
1643/*
1644 * free memory that was allocated
1645 */
1646static void bitmap_free(struct bitmap *bitmap)
1647{
1648 unsigned long k, pages;
1649 struct bitmap_page *bp;
1650
1651 if (!bitmap) /* there was no bitmap */
1652 return;
1653
1654 /* release the bitmap file and kill the daemon */
1655 bitmap_file_put(bitmap);
1656
1657 bp = bitmap->bp;
1658 pages = bitmap->pages;
1659
1660 /* free all allocated memory */
1661
1662 if (bp) /* deallocate the page memory */
1663 for (k = 0; k < pages; k++)
1664 if (bp[k].map && !bp[k].hijacked)
1665 kfree(bp[k].map);
1666 kfree(bp);
1667 kfree(bitmap);
1668}
1669
1670void bitmap_destroy(struct mddev *mddev)
1671{
1672 struct bitmap *bitmap = mddev->bitmap;
1673
1674 if (!bitmap) /* there was no bitmap */
1675 return;
1676
1677 mutex_lock(&mddev->bitmap_info.mutex);
1678 mddev->bitmap = NULL; /* disconnect from the md device */
1679 mutex_unlock(&mddev->bitmap_info.mutex);
1680 if (mddev->thread)
1681 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1682
1683 if (bitmap->sysfs_can_clear)
1684 sysfs_put(bitmap->sysfs_can_clear);
1685
1686 bitmap_free(bitmap);
1687}
1688
1689/*
1690 * initialize the bitmap structure
1691 * if this returns an error, bitmap_destroy must be called to do clean up
1692 */
1693int bitmap_create(struct mddev *mddev)
1694{
1695 struct bitmap *bitmap;
1696 sector_t blocks = mddev->resync_max_sectors;
1697 unsigned long chunks;
1698 unsigned long pages;
1699 struct file *file = mddev->bitmap_info.file;
1700 int err;
1701 struct sysfs_dirent *bm = NULL;
1702
1703 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1704
1705 if (!file
1706 && !mddev->bitmap_info.offset) /* bitmap disabled, nothing to do */
1707 return 0;
1708
1709 BUG_ON(file && mddev->bitmap_info.offset);
1710
1711 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1712 if (!bitmap)
1713 return -ENOMEM;
1714
1715 spin_lock_init(&bitmap->lock);
1716 atomic_set(&bitmap->pending_writes, 0);
1717 init_waitqueue_head(&bitmap->write_wait);
1718 init_waitqueue_head(&bitmap->overflow_wait);
1719 init_waitqueue_head(&bitmap->behind_wait);
1720
1721 bitmap->mddev = mddev;
1722
1723 if (mddev->kobj.sd)
1724 bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap");
1725 if (bm) {
1726 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear");
1727 sysfs_put(bm);
1728 } else
1729 bitmap->sysfs_can_clear = NULL;
1730
1731 bitmap->file = file;
1732 if (file) {
1733 get_file(file);
1734 /* As future accesses to this file will use bmap,
1735 * and bypass the page cache, we must sync the file
1736 * first.
1737 */
1738 vfs_fsync(file, 1);
1739 }
1740 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1741 if (!mddev->bitmap_info.external) {
1742 /*
1743 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1744 * instructing us to create a new on-disk bitmap instance.
1745 */
1746 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1747 err = bitmap_new_disk_sb(bitmap);
1748 else
1749 err = bitmap_read_sb(bitmap);
1750 } else {
1751 err = 0;
1752 if (mddev->bitmap_info.chunksize == 0 ||
1753 mddev->bitmap_info.daemon_sleep == 0)
1754 /* chunksize and time_base need to be
1755 * set first. */
1756 err = -EINVAL;
1757 }
1758 if (err)
1759 goto error;
1760
1761 bitmap->daemon_lastrun = jiffies;
1762 bitmap->chunkshift = ffz(~mddev->bitmap_info.chunksize);
1763
1764 /* now that chunksize and chunkshift are set, we can use these macros */
1765 chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) >>
1766 CHUNK_BLOCK_SHIFT(bitmap);
1767 pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1768
1769 BUG_ON(!pages);
1770
1771 bitmap->chunks = chunks;
1772 bitmap->pages = pages;
1773 bitmap->missing_pages = pages;
1774
1775 bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1776
1777 err = -ENOMEM;
1778 if (!bitmap->bp)
1779 goto error;
1780
1781 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1782 pages, bmname(bitmap));
1783
1784 mddev->bitmap = bitmap;
1785
1786
1787 return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
1788
1789 error:
1790 bitmap_free(bitmap);
1791 return err;
1792}
1793
1794int bitmap_load(struct mddev *mddev)
1795{
1796 int err = 0;
1797 sector_t start = 0;
1798 sector_t sector = 0;
1799 struct bitmap *bitmap = mddev->bitmap;
1800
1801 if (!bitmap)
1802 goto out;
1803
1804 /* Clear out old bitmap info first: Either there is none, or we
1805 * are resuming after someone else has possibly changed things,
1806 * so we should forget old cached info.
1807 * All chunks should be clean, but some might need_sync.
1808 */
1809 while (sector < mddev->resync_max_sectors) {
1810 sector_t blocks;
1811 bitmap_start_sync(bitmap, sector, &blocks, 0);
1812 sector += blocks;
1813 }
1814 bitmap_close_sync(bitmap);
1815
1816 if (mddev->degraded == 0
1817 || bitmap->events_cleared == mddev->events)
1818 /* no need to keep dirty bits to optimise a
1819 * re-add of a missing device */
1820 start = mddev->recovery_cp;
1821
1822 err = bitmap_init_from_disk(bitmap, start);
1823
1824 if (err)
1825 goto out;
1826
1827 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1828 md_wakeup_thread(mddev->thread);
1829
1830 bitmap_update_sb(bitmap);
1831
1832 if (bitmap->flags & BITMAP_WRITE_ERROR)
1833 err = -EIO;
1834out:
1835 return err;
1836}
1837EXPORT_SYMBOL_GPL(bitmap_load);
1838
1839static ssize_t
1840location_show(struct mddev *mddev, char *page)
1841{
1842 ssize_t len;
1843 if (mddev->bitmap_info.file)
1844 len = sprintf(page, "file");
1845 else if (mddev->bitmap_info.offset)
1846 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
1847 else
1848 len = sprintf(page, "none");
1849 len += sprintf(page+len, "\n");
1850 return len;
1851}
1852
1853static ssize_t
1854location_store(struct mddev *mddev, const char *buf, size_t len)
1855{
1856
1857 if (mddev->pers) {
1858 if (!mddev->pers->quiesce)
1859 return -EBUSY;
1860 if (mddev->recovery || mddev->sync_thread)
1861 return -EBUSY;
1862 }
1863
1864 if (mddev->bitmap || mddev->bitmap_info.file ||
1865 mddev->bitmap_info.offset) {
1866 /* bitmap already configured. Only option is to clear it */
1867 if (strncmp(buf, "none", 4) != 0)
1868 return -EBUSY;
1869 if (mddev->pers) {
1870 mddev->pers->quiesce(mddev, 1);
1871 bitmap_destroy(mddev);
1872 mddev->pers->quiesce(mddev, 0);
1873 }
1874 mddev->bitmap_info.offset = 0;
1875 if (mddev->bitmap_info.file) {
1876 struct file *f = mddev->bitmap_info.file;
1877 mddev->bitmap_info.file = NULL;
1878 restore_bitmap_write_access(f);
1879 fput(f);
1880 }
1881 } else {
1882 /* No bitmap, OK to set a location */
1883 long long offset;
1884 if (strncmp(buf, "none", 4) == 0)
1885 /* nothing to be done */;
1886 else if (strncmp(buf, "file:", 5) == 0) {
1887 /* Not supported yet */
1888 return -EINVAL;
1889 } else {
1890 int rv;
1891 if (buf[0] == '+')
1892 rv = strict_strtoll(buf+1, 10, &offset);
1893 else
1894 rv = strict_strtoll(buf, 10, &offset);
1895 if (rv)
1896 return rv;
1897 if (offset == 0)
1898 return -EINVAL;
1899 if (mddev->bitmap_info.external == 0 &&
1900 mddev->major_version == 0 &&
1901 offset != mddev->bitmap_info.default_offset)
1902 return -EINVAL;
1903 mddev->bitmap_info.offset = offset;
1904 if (mddev->pers) {
1905 mddev->pers->quiesce(mddev, 1);
1906 rv = bitmap_create(mddev);
1907 if (rv) {
1908 bitmap_destroy(mddev);
1909 mddev->bitmap_info.offset = 0;
1910 }
1911 mddev->pers->quiesce(mddev, 0);
1912 if (rv)
1913 return rv;
1914 }
1915 }
1916 }
1917 if (!mddev->external) {
1918 /* Ensure new bitmap info is stored in
1919 * metadata promptly.
1920 */
1921 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1922 md_wakeup_thread(mddev->thread);
1923 }
1924 return len;
1925}
1926
1927static struct md_sysfs_entry bitmap_location =
1928__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
1929
1930static ssize_t
1931timeout_show(struct mddev *mddev, char *page)
1932{
1933 ssize_t len;
1934 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
1935 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
1936
1937 len = sprintf(page, "%lu", secs);
1938 if (jifs)
1939 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
1940 len += sprintf(page+len, "\n");
1941 return len;
1942}
1943
1944static ssize_t
1945timeout_store(struct mddev *mddev, const char *buf, size_t len)
1946{
1947 /* timeout can be set at any time */
1948 unsigned long timeout;
1949 int rv = strict_strtoul_scaled(buf, &timeout, 4);
1950 if (rv)
1951 return rv;
1952
1953 /* just to make sure we don't overflow... */
1954 if (timeout >= LONG_MAX / HZ)
1955 return -EINVAL;
1956
1957 timeout = timeout * HZ / 10000;
1958
1959 if (timeout >= MAX_SCHEDULE_TIMEOUT)
1960 timeout = MAX_SCHEDULE_TIMEOUT-1;
1961 if (timeout < 1)
1962 timeout = 1;
1963 mddev->bitmap_info.daemon_sleep = timeout;
1964 if (mddev->thread) {
1965 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
1966 * the bitmap is all clean and we don't need to
1967 * adjust the timeout right now
1968 */
1969 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
1970 mddev->thread->timeout = timeout;
1971 md_wakeup_thread(mddev->thread);
1972 }
1973 }
1974 return len;
1975}
1976
1977static struct md_sysfs_entry bitmap_timeout =
1978__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
1979
1980static ssize_t
1981backlog_show(struct mddev *mddev, char *page)
1982{
1983 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
1984}
1985
1986static ssize_t
1987backlog_store(struct mddev *mddev, const char *buf, size_t len)
1988{
1989 unsigned long backlog;
1990 int rv = strict_strtoul(buf, 10, &backlog);
1991 if (rv)
1992 return rv;
1993 if (backlog > COUNTER_MAX)
1994 return -EINVAL;
1995 mddev->bitmap_info.max_write_behind = backlog;
1996 return len;
1997}
1998
1999static struct md_sysfs_entry bitmap_backlog =
2000__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2001
2002static ssize_t
2003chunksize_show(struct mddev *mddev, char *page)
2004{
2005 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2006}
2007
2008static ssize_t
2009chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2010{
2011 /* Can only be changed when no bitmap is active */
2012 int rv;
2013 unsigned long csize;
2014 if (mddev->bitmap)
2015 return -EBUSY;
2016 rv = strict_strtoul(buf, 10, &csize);
2017 if (rv)
2018 return rv;
2019 if (csize < 512 ||
2020 !is_power_of_2(csize))
2021 return -EINVAL;
2022 mddev->bitmap_info.chunksize = csize;
2023 return len;
2024}
2025
2026static struct md_sysfs_entry bitmap_chunksize =
2027__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2028
2029static ssize_t metadata_show(struct mddev *mddev, char *page)
2030{
2031 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2032 ? "external" : "internal"));
2033}
2034
2035static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2036{
2037 if (mddev->bitmap ||
2038 mddev->bitmap_info.file ||
2039 mddev->bitmap_info.offset)
2040 return -EBUSY;
2041 if (strncmp(buf, "external", 8) == 0)
2042 mddev->bitmap_info.external = 1;
2043 else if (strncmp(buf, "internal", 8) == 0)
2044 mddev->bitmap_info.external = 0;
2045 else
2046 return -EINVAL;
2047 return len;
2048}
2049
2050static struct md_sysfs_entry bitmap_metadata =
2051__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2052
2053static ssize_t can_clear_show(struct mddev *mddev, char *page)
2054{
2055 int len;
2056 if (mddev->bitmap)
2057 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2058 "false" : "true"));
2059 else
2060 len = sprintf(page, "\n");
2061 return len;
2062}
2063
2064static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2065{
2066 if (mddev->bitmap == NULL)
2067 return -ENOENT;
2068 if (strncmp(buf, "false", 5) == 0)
2069 mddev->bitmap->need_sync = 1;
2070 else if (strncmp(buf, "true", 4) == 0) {
2071 if (mddev->degraded)
2072 return -EBUSY;
2073 mddev->bitmap->need_sync = 0;
2074 } else
2075 return -EINVAL;
2076 return len;
2077}
2078
2079static struct md_sysfs_entry bitmap_can_clear =
2080__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2081
2082static ssize_t
2083behind_writes_used_show(struct mddev *mddev, char *page)
2084{
2085 if (mddev->bitmap == NULL)
2086 return sprintf(page, "0\n");
2087 return sprintf(page, "%lu\n",
2088 mddev->bitmap->behind_writes_used);
2089}
2090
2091static ssize_t
2092behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2093{
2094 if (mddev->bitmap)
2095 mddev->bitmap->behind_writes_used = 0;
2096 return len;
2097}
2098
2099static struct md_sysfs_entry max_backlog_used =
2100__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2101 behind_writes_used_show, behind_writes_used_reset);
2102
2103static struct attribute *md_bitmap_attrs[] = {
2104 &bitmap_location.attr,
2105 &bitmap_timeout.attr,
2106 &bitmap_backlog.attr,
2107 &bitmap_chunksize.attr,
2108 &bitmap_metadata.attr,
2109 &bitmap_can_clear.attr,
2110 &max_backlog_used.attr,
2111 NULL
2112};
2113struct attribute_group md_bitmap_group = {
2114 .name = "bitmap",
2115 .attrs = md_bitmap_attrs,
2116};
2117