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1/*
2 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 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 <linux/seq_file.h>
30#include "md.h"
31#include "bitmap.h"
32
33static inline char *bmname(struct bitmap *bitmap)
34{
35 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
36}
37
38/*
39 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
40 *
41 * 1) check to see if this page is allocated, if it's not then try to alloc
42 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
43 * page pointer directly as a counter
44 *
45 * if we find our page, we increment the page's refcount so that it stays
46 * allocated while we're using it
47 */
48static int bitmap_checkpage(struct bitmap_counts *bitmap,
49 unsigned long page, int create)
50__releases(bitmap->lock)
51__acquires(bitmap->lock)
52{
53 unsigned char *mappage;
54
55 if (page >= bitmap->pages) {
56 /* This can happen if bitmap_start_sync goes beyond
57 * End-of-device while looking for a whole page.
58 * It is harmless.
59 */
60 return -EINVAL;
61 }
62
63 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
64 return 0;
65
66 if (bitmap->bp[page].map) /* page is already allocated, just return */
67 return 0;
68
69 if (!create)
70 return -ENOENT;
71
72 /* this page has not been allocated yet */
73
74 spin_unlock_irq(&bitmap->lock);
75 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
76 spin_lock_irq(&bitmap->lock);
77
78 if (mappage == NULL) {
79 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
80 /* failed - set the hijacked flag so that we can use the
81 * pointer as a counter */
82 if (!bitmap->bp[page].map)
83 bitmap->bp[page].hijacked = 1;
84 } else if (bitmap->bp[page].map ||
85 bitmap->bp[page].hijacked) {
86 /* somebody beat us to getting the page */
87 kfree(mappage);
88 return 0;
89 } else {
90
91 /* no page was in place and we have one, so install it */
92
93 bitmap->bp[page].map = mappage;
94 bitmap->missing_pages--;
95 }
96 return 0;
97}
98
99/* if page is completely empty, put it back on the free list, or dealloc it */
100/* if page was hijacked, unmark the flag so it might get alloced next time */
101/* Note: lock should be held when calling this */
102static void bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
103{
104 char *ptr;
105
106 if (bitmap->bp[page].count) /* page is still busy */
107 return;
108
109 /* page is no longer in use, it can be released */
110
111 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
112 bitmap->bp[page].hijacked = 0;
113 bitmap->bp[page].map = NULL;
114 } else {
115 /* normal case, free the page */
116 ptr = bitmap->bp[page].map;
117 bitmap->bp[page].map = NULL;
118 bitmap->missing_pages++;
119 kfree(ptr);
120 }
121}
122
123/*
124 * bitmap file handling - read and write the bitmap file and its superblock
125 */
126
127/*
128 * basic page I/O operations
129 */
130
131/* IO operations when bitmap is stored near all superblocks */
132static int read_sb_page(struct mddev *mddev, loff_t offset,
133 struct page *page,
134 unsigned long index, int size)
135{
136 /* choose a good rdev and read the page from there */
137
138 struct md_rdev *rdev;
139 sector_t target;
140
141 rdev_for_each(rdev, mddev) {
142 if (! test_bit(In_sync, &rdev->flags)
143 || test_bit(Faulty, &rdev->flags))
144 continue;
145
146 target = offset + index * (PAGE_SIZE/512);
147
148 if (sync_page_io(rdev, target,
149 roundup(size, bdev_logical_block_size(rdev->bdev)),
150 page, READ, true)) {
151 page->index = index;
152 return 0;
153 }
154 }
155 return -EIO;
156}
157
158static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
159{
160 /* Iterate the disks of an mddev, using rcu to protect access to the
161 * linked list, and raising the refcount of devices we return to ensure
162 * they don't disappear while in use.
163 * As devices are only added or removed when raid_disk is < 0 and
164 * nr_pending is 0 and In_sync is clear, the entries we return will
165 * still be in the same position on the list when we re-enter
166 * list_for_each_continue_rcu.
167 */
168 struct list_head *pos;
169 rcu_read_lock();
170 if (rdev == NULL)
171 /* start at the beginning */
172 pos = &mddev->disks;
173 else {
174 /* release the previous rdev and start from there. */
175 rdev_dec_pending(rdev, mddev);
176 pos = &rdev->same_set;
177 }
178 list_for_each_continue_rcu(pos, &mddev->disks) {
179 rdev = list_entry(pos, struct md_rdev, same_set);
180 if (rdev->raid_disk >= 0 &&
181 !test_bit(Faulty, &rdev->flags)) {
182 /* this is a usable devices */
183 atomic_inc(&rdev->nr_pending);
184 rcu_read_unlock();
185 return rdev;
186 }
187 }
188 rcu_read_unlock();
189 return NULL;
190}
191
192static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
193{
194 struct md_rdev *rdev = NULL;
195 struct block_device *bdev;
196 struct mddev *mddev = bitmap->mddev;
197 struct bitmap_storage *store = &bitmap->storage;
198
199 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
200 int size = PAGE_SIZE;
201 loff_t offset = mddev->bitmap_info.offset;
202
203 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
204
205 if (page->index == store->file_pages-1) {
206 int last_page_size = store->bytes & (PAGE_SIZE-1);
207 if (last_page_size == 0)
208 last_page_size = PAGE_SIZE;
209 size = roundup(last_page_size,
210 bdev_logical_block_size(bdev));
211 }
212 /* Just make sure we aren't corrupting data or
213 * metadata
214 */
215 if (mddev->external) {
216 /* Bitmap could be anywhere. */
217 if (rdev->sb_start + offset + (page->index
218 * (PAGE_SIZE/512))
219 > rdev->data_offset
220 &&
221 rdev->sb_start + offset
222 < (rdev->data_offset + mddev->dev_sectors
223 + (PAGE_SIZE/512)))
224 goto bad_alignment;
225 } else if (offset < 0) {
226 /* DATA BITMAP METADATA */
227 if (offset
228 + (long)(page->index * (PAGE_SIZE/512))
229 + size/512 > 0)
230 /* bitmap runs in to metadata */
231 goto bad_alignment;
232 if (rdev->data_offset + mddev->dev_sectors
233 > rdev->sb_start + offset)
234 /* data runs in to bitmap */
235 goto bad_alignment;
236 } else if (rdev->sb_start < rdev->data_offset) {
237 /* METADATA BITMAP DATA */
238 if (rdev->sb_start
239 + offset
240 + page->index*(PAGE_SIZE/512) + size/512
241 > rdev->data_offset)
242 /* bitmap runs in to data */
243 goto bad_alignment;
244 } else {
245 /* DATA METADATA BITMAP - no problems */
246 }
247 md_super_write(mddev, rdev,
248 rdev->sb_start + offset
249 + page->index * (PAGE_SIZE/512),
250 size,
251 page);
252 }
253
254 if (wait)
255 md_super_wait(mddev);
256 return 0;
257
258 bad_alignment:
259 return -EINVAL;
260}
261
262static void bitmap_file_kick(struct bitmap *bitmap);
263/*
264 * write out a page to a file
265 */
266static void write_page(struct bitmap *bitmap, struct page *page, int wait)
267{
268 struct buffer_head *bh;
269
270 if (bitmap->storage.file == NULL) {
271 switch (write_sb_page(bitmap, page, wait)) {
272 case -EINVAL:
273 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
274 }
275 } else {
276
277 bh = page_buffers(page);
278
279 while (bh && bh->b_blocknr) {
280 atomic_inc(&bitmap->pending_writes);
281 set_buffer_locked(bh);
282 set_buffer_mapped(bh);
283 submit_bh(WRITE | REQ_SYNC, bh);
284 bh = bh->b_this_page;
285 }
286
287 if (wait)
288 wait_event(bitmap->write_wait,
289 atomic_read(&bitmap->pending_writes)==0);
290 }
291 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
292 bitmap_file_kick(bitmap);
293}
294
295static void end_bitmap_write(struct buffer_head *bh, int uptodate)
296{
297 struct bitmap *bitmap = bh->b_private;
298
299 if (!uptodate)
300 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
301 if (atomic_dec_and_test(&bitmap->pending_writes))
302 wake_up(&bitmap->write_wait);
303}
304
305/* copied from buffer.c */
306static void
307__clear_page_buffers(struct page *page)
308{
309 ClearPagePrivate(page);
310 set_page_private(page, 0);
311 page_cache_release(page);
312}
313static void free_buffers(struct page *page)
314{
315 struct buffer_head *bh;
316
317 if (!PagePrivate(page))
318 return;
319
320 bh = page_buffers(page);
321 while (bh) {
322 struct buffer_head *next = bh->b_this_page;
323 free_buffer_head(bh);
324 bh = next;
325 }
326 __clear_page_buffers(page);
327 put_page(page);
328}
329
330/* read a page from a file.
331 * We both read the page, and attach buffers to the page to record the
332 * address of each block (using bmap). These addresses will be used
333 * to write the block later, completely bypassing the filesystem.
334 * This usage is similar to how swap files are handled, and allows us
335 * to write to a file with no concerns of memory allocation failing.
336 */
337static int read_page(struct file *file, unsigned long index,
338 struct bitmap *bitmap,
339 unsigned long count,
340 struct page *page)
341{
342 int ret = 0;
343 struct inode *inode = file->f_path.dentry->d_inode;
344 struct buffer_head *bh;
345 sector_t block;
346
347 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
348 (unsigned long long)index << PAGE_SHIFT);
349
350 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
351 if (!bh) {
352 ret = -ENOMEM;
353 goto out;
354 }
355 attach_page_buffers(page, bh);
356 block = index << (PAGE_SHIFT - inode->i_blkbits);
357 while (bh) {
358 if (count == 0)
359 bh->b_blocknr = 0;
360 else {
361 bh->b_blocknr = bmap(inode, block);
362 if (bh->b_blocknr == 0) {
363 /* Cannot use this file! */
364 ret = -EINVAL;
365 goto out;
366 }
367 bh->b_bdev = inode->i_sb->s_bdev;
368 if (count < (1<<inode->i_blkbits))
369 count = 0;
370 else
371 count -= (1<<inode->i_blkbits);
372
373 bh->b_end_io = end_bitmap_write;
374 bh->b_private = bitmap;
375 atomic_inc(&bitmap->pending_writes);
376 set_buffer_locked(bh);
377 set_buffer_mapped(bh);
378 submit_bh(READ, bh);
379 }
380 block++;
381 bh = bh->b_this_page;
382 }
383 page->index = index;
384
385 wait_event(bitmap->write_wait,
386 atomic_read(&bitmap->pending_writes)==0);
387 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
388 ret = -EIO;
389out:
390 if (ret)
391 printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %d\n",
392 (int)PAGE_SIZE,
393 (unsigned long long)index << PAGE_SHIFT,
394 ret);
395 return ret;
396}
397
398/*
399 * bitmap file superblock operations
400 */
401
402/* update the event counter and sync the superblock to disk */
403void bitmap_update_sb(struct bitmap *bitmap)
404{
405 bitmap_super_t *sb;
406
407 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
408 return;
409 if (bitmap->mddev->bitmap_info.external)
410 return;
411 if (!bitmap->storage.sb_page) /* no superblock */
412 return;
413 sb = kmap_atomic(bitmap->storage.sb_page);
414 sb->events = cpu_to_le64(bitmap->mddev->events);
415 if (bitmap->mddev->events < bitmap->events_cleared)
416 /* rocking back to read-only */
417 bitmap->events_cleared = bitmap->mddev->events;
418 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
419 sb->state = cpu_to_le32(bitmap->flags);
420 /* Just in case these have been changed via sysfs: */
421 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
422 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
423 /* This might have been changed by a reshape */
424 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
425 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
426 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
427 bitmap_info.space);
428 kunmap_atomic(sb);
429 write_page(bitmap, bitmap->storage.sb_page, 1);
430}
431
432/* print out the bitmap file superblock */
433void bitmap_print_sb(struct bitmap *bitmap)
434{
435 bitmap_super_t *sb;
436
437 if (!bitmap || !bitmap->storage.sb_page)
438 return;
439 sb = kmap_atomic(bitmap->storage.sb_page);
440 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
441 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
442 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
443 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
444 *(__u32 *)(sb->uuid+0),
445 *(__u32 *)(sb->uuid+4),
446 *(__u32 *)(sb->uuid+8),
447 *(__u32 *)(sb->uuid+12));
448 printk(KERN_DEBUG " events: %llu\n",
449 (unsigned long long) le64_to_cpu(sb->events));
450 printk(KERN_DEBUG "events cleared: %llu\n",
451 (unsigned long long) le64_to_cpu(sb->events_cleared));
452 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
453 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
454 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
455 printk(KERN_DEBUG " sync size: %llu KB\n",
456 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
457 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
458 kunmap_atomic(sb);
459}
460
461/*
462 * bitmap_new_disk_sb
463 * @bitmap
464 *
465 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
466 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
467 * This function verifies 'bitmap_info' and populates the on-disk bitmap
468 * structure, which is to be written to disk.
469 *
470 * Returns: 0 on success, -Exxx on error
471 */
472static int bitmap_new_disk_sb(struct bitmap *bitmap)
473{
474 bitmap_super_t *sb;
475 unsigned long chunksize, daemon_sleep, write_behind;
476 int err = -EINVAL;
477
478 bitmap->storage.sb_page = alloc_page(GFP_KERNEL);
479 if (IS_ERR(bitmap->storage.sb_page)) {
480 err = PTR_ERR(bitmap->storage.sb_page);
481 bitmap->storage.sb_page = NULL;
482 return err;
483 }
484 bitmap->storage.sb_page->index = 0;
485
486 sb = kmap_atomic(bitmap->storage.sb_page);
487
488 sb->magic = cpu_to_le32(BITMAP_MAGIC);
489 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
490
491 chunksize = bitmap->mddev->bitmap_info.chunksize;
492 BUG_ON(!chunksize);
493 if (!is_power_of_2(chunksize)) {
494 kunmap_atomic(sb);
495 printk(KERN_ERR "bitmap chunksize not a power of 2\n");
496 return -EINVAL;
497 }
498 sb->chunksize = cpu_to_le32(chunksize);
499
500 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
501 if (!daemon_sleep ||
502 (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
503 printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
504 daemon_sleep = 5 * HZ;
505 }
506 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
507 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
508
509 /*
510 * FIXME: write_behind for RAID1. If not specified, what
511 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
512 */
513 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
514 if (write_behind > COUNTER_MAX)
515 write_behind = COUNTER_MAX / 2;
516 sb->write_behind = cpu_to_le32(write_behind);
517 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
518
519 /* keep the array size field of the bitmap superblock up to date */
520 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
521
522 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
523
524 set_bit(BITMAP_STALE, &bitmap->flags);
525 sb->state = cpu_to_le32(bitmap->flags);
526 bitmap->events_cleared = bitmap->mddev->events;
527 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
528
529 kunmap_atomic(sb);
530
531 return 0;
532}
533
534/* read the superblock from the bitmap file and initialize some bitmap fields */
535static int bitmap_read_sb(struct bitmap *bitmap)
536{
537 char *reason = NULL;
538 bitmap_super_t *sb;
539 unsigned long chunksize, daemon_sleep, write_behind;
540 unsigned long long events;
541 unsigned long sectors_reserved = 0;
542 int err = -EINVAL;
543 struct page *sb_page;
544
545 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
546 chunksize = 128 * 1024 * 1024;
547 daemon_sleep = 5 * HZ;
548 write_behind = 0;
549 set_bit(BITMAP_STALE, &bitmap->flags);
550 err = 0;
551 goto out_no_sb;
552 }
553 /* page 0 is the superblock, read it... */
554 sb_page = alloc_page(GFP_KERNEL);
555 if (!sb_page)
556 return -ENOMEM;
557 bitmap->storage.sb_page = sb_page;
558
559 if (bitmap->storage.file) {
560 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
561 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
562
563 err = read_page(bitmap->storage.file, 0,
564 bitmap, bytes, sb_page);
565 } else {
566 err = read_sb_page(bitmap->mddev,
567 bitmap->mddev->bitmap_info.offset,
568 sb_page,
569 0, sizeof(bitmap_super_t));
570 }
571 if (err)
572 return err;
573
574 sb = kmap_atomic(sb_page);
575
576 chunksize = le32_to_cpu(sb->chunksize);
577 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
578 write_behind = le32_to_cpu(sb->write_behind);
579 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
580
581 /* verify that the bitmap-specific fields are valid */
582 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
583 reason = "bad magic";
584 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
585 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
586 reason = "unrecognized superblock version";
587 else if (chunksize < 512)
588 reason = "bitmap chunksize too small";
589 else if (!is_power_of_2(chunksize))
590 reason = "bitmap chunksize not a power of 2";
591 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
592 reason = "daemon sleep period out of range";
593 else if (write_behind > COUNTER_MAX)
594 reason = "write-behind limit out of range (0 - 16383)";
595 if (reason) {
596 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
597 bmname(bitmap), reason);
598 goto out;
599 }
600
601 /* keep the array size field of the bitmap superblock up to date */
602 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
603
604 if (bitmap->mddev->persistent) {
605 /*
606 * We have a persistent array superblock, so compare the
607 * bitmap's UUID and event counter to the mddev's
608 */
609 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
610 printk(KERN_INFO
611 "%s: bitmap superblock UUID mismatch\n",
612 bmname(bitmap));
613 goto out;
614 }
615 events = le64_to_cpu(sb->events);
616 if (events < bitmap->mddev->events) {
617 printk(KERN_INFO
618 "%s: bitmap file is out of date (%llu < %llu) "
619 "-- forcing full recovery\n",
620 bmname(bitmap), events,
621 (unsigned long long) bitmap->mddev->events);
622 set_bit(BITMAP_STALE, &bitmap->flags);
623 }
624 }
625
626 /* assign fields using values from superblock */
627 bitmap->flags |= le32_to_cpu(sb->state);
628 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
629 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
630 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
631 err = 0;
632out:
633 kunmap_atomic(sb);
634out_no_sb:
635 if (test_bit(BITMAP_STALE, &bitmap->flags))
636 bitmap->events_cleared = bitmap->mddev->events;
637 bitmap->mddev->bitmap_info.chunksize = chunksize;
638 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
639 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
640 if (bitmap->mddev->bitmap_info.space == 0 ||
641 bitmap->mddev->bitmap_info.space > sectors_reserved)
642 bitmap->mddev->bitmap_info.space = sectors_reserved;
643 if (err)
644 bitmap_print_sb(bitmap);
645 return err;
646}
647
648/*
649 * general bitmap file operations
650 */
651
652/*
653 * on-disk bitmap:
654 *
655 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
656 * file a page at a time. There's a superblock at the start of the file.
657 */
658/* calculate the index of the page that contains this bit */
659static inline unsigned long file_page_index(struct bitmap_storage *store,
660 unsigned long chunk)
661{
662 if (store->sb_page)
663 chunk += sizeof(bitmap_super_t) << 3;
664 return chunk >> PAGE_BIT_SHIFT;
665}
666
667/* calculate the (bit) offset of this bit within a page */
668static inline unsigned long file_page_offset(struct bitmap_storage *store,
669 unsigned long chunk)
670{
671 if (store->sb_page)
672 chunk += sizeof(bitmap_super_t) << 3;
673 return chunk & (PAGE_BITS - 1);
674}
675
676/*
677 * return a pointer to the page in the filemap that contains the given bit
678 *
679 * this lookup is complicated by the fact that the bitmap sb might be exactly
680 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
681 * 0 or page 1
682 */
683static inline struct page *filemap_get_page(struct bitmap_storage *store,
684 unsigned long chunk)
685{
686 if (file_page_index(store, chunk) >= store->file_pages)
687 return NULL;
688 return store->filemap[file_page_index(store, chunk)
689 - file_page_index(store, 0)];
690}
691
692static int bitmap_storage_alloc(struct bitmap_storage *store,
693 unsigned long chunks, int with_super)
694{
695 int pnum;
696 unsigned long num_pages;
697 unsigned long bytes;
698
699 bytes = DIV_ROUND_UP(chunks, 8);
700 if (with_super)
701 bytes += sizeof(bitmap_super_t);
702
703 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
704
705 store->filemap = kmalloc(sizeof(struct page *)
706 * num_pages, GFP_KERNEL);
707 if (!store->filemap)
708 return -ENOMEM;
709
710 if (with_super && !store->sb_page) {
711 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
712 if (store->sb_page == NULL)
713 return -ENOMEM;
714 store->sb_page->index = 0;
715 }
716 pnum = 0;
717 if (store->sb_page) {
718 store->filemap[0] = store->sb_page;
719 pnum = 1;
720 }
721 for ( ; pnum < num_pages; pnum++) {
722 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
723 if (!store->filemap[pnum]) {
724 store->file_pages = pnum;
725 return -ENOMEM;
726 }
727 store->filemap[pnum]->index = pnum;
728 }
729 store->file_pages = pnum;
730
731 /* We need 4 bits per page, rounded up to a multiple
732 * of sizeof(unsigned long) */
733 store->filemap_attr = kzalloc(
734 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
735 GFP_KERNEL);
736 if (!store->filemap_attr)
737 return -ENOMEM;
738
739 store->bytes = bytes;
740
741 return 0;
742}
743
744static void bitmap_file_unmap(struct bitmap_storage *store)
745{
746 struct page **map, *sb_page;
747 int pages;
748 struct file *file;
749
750 file = store->file;
751 map = store->filemap;
752 pages = store->file_pages;
753 sb_page = store->sb_page;
754
755 while (pages--)
756 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
757 free_buffers(map[pages]);
758 kfree(map);
759 kfree(store->filemap_attr);
760
761 if (sb_page)
762 free_buffers(sb_page);
763
764 if (file) {
765 struct inode *inode = file->f_path.dentry->d_inode;
766 invalidate_mapping_pages(inode->i_mapping, 0, -1);
767 fput(file);
768 }
769}
770
771/*
772 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
773 * then it is no longer reliable, so we stop using it and we mark the file
774 * as failed in the superblock
775 */
776static void bitmap_file_kick(struct bitmap *bitmap)
777{
778 char *path, *ptr = NULL;
779
780 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
781 bitmap_update_sb(bitmap);
782
783 if (bitmap->storage.file) {
784 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
785 if (path)
786 ptr = d_path(&bitmap->storage.file->f_path,
787 path, PAGE_SIZE);
788
789 printk(KERN_ALERT
790 "%s: kicking failed bitmap file %s from array!\n",
791 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
792
793 kfree(path);
794 } else
795 printk(KERN_ALERT
796 "%s: disabling internal bitmap due to errors\n",
797 bmname(bitmap));
798 }
799}
800
801enum bitmap_page_attr {
802 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
803 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
804 * i.e. counter is 1 or 2. */
805 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
806};
807
808static inline void set_page_attr(struct bitmap *bitmap, int pnum,
809 enum bitmap_page_attr attr)
810{
811 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
812}
813
814static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
815 enum bitmap_page_attr attr)
816{
817 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
818}
819
820static inline int test_page_attr(struct bitmap *bitmap, int pnum,
821 enum bitmap_page_attr attr)
822{
823 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
824}
825
826static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
827 enum bitmap_page_attr attr)
828{
829 return test_and_clear_bit((pnum<<2) + attr,
830 bitmap->storage.filemap_attr);
831}
832/*
833 * bitmap_file_set_bit -- called before performing a write to the md device
834 * to set (and eventually sync) a particular bit in the bitmap file
835 *
836 * we set the bit immediately, then we record the page number so that
837 * when an unplug occurs, we can flush the dirty pages out to disk
838 */
839static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
840{
841 unsigned long bit;
842 struct page *page;
843 void *kaddr;
844 unsigned long chunk = block >> bitmap->counts.chunkshift;
845
846 page = filemap_get_page(&bitmap->storage, chunk);
847 if (!page)
848 return;
849 bit = file_page_offset(&bitmap->storage, chunk);
850
851 /* set the bit */
852 kaddr = kmap_atomic(page);
853 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
854 set_bit(bit, kaddr);
855 else
856 test_and_set_bit_le(bit, kaddr);
857 kunmap_atomic(kaddr);
858 pr_debug("set file bit %lu page %lu\n", bit, page->index);
859 /* record page number so it gets flushed to disk when unplug occurs */
860 set_page_attr(bitmap, page->index, BITMAP_PAGE_DIRTY);
861}
862
863static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
864{
865 unsigned long bit;
866 struct page *page;
867 void *paddr;
868 unsigned long chunk = block >> bitmap->counts.chunkshift;
869
870 page = filemap_get_page(&bitmap->storage, chunk);
871 if (!page)
872 return;
873 bit = file_page_offset(&bitmap->storage, chunk);
874 paddr = kmap_atomic(page);
875 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
876 clear_bit(bit, paddr);
877 else
878 test_and_clear_bit_le(bit, paddr);
879 kunmap_atomic(paddr);
880 if (!test_page_attr(bitmap, page->index, BITMAP_PAGE_NEEDWRITE)) {
881 set_page_attr(bitmap, page->index, BITMAP_PAGE_PENDING);
882 bitmap->allclean = 0;
883 }
884}
885
886/* this gets called when the md device is ready to unplug its underlying
887 * (slave) device queues -- before we let any writes go down, we need to
888 * sync the dirty pages of the bitmap file to disk */
889void bitmap_unplug(struct bitmap *bitmap)
890{
891 unsigned long i;
892 int dirty, need_write;
893 int wait = 0;
894
895 if (!bitmap || !bitmap->storage.filemap ||
896 test_bit(BITMAP_STALE, &bitmap->flags))
897 return;
898
899 /* look at each page to see if there are any set bits that need to be
900 * flushed out to disk */
901 for (i = 0; i < bitmap->storage.file_pages; i++) {
902 if (!bitmap->storage.filemap)
903 return;
904 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
905 need_write = test_and_clear_page_attr(bitmap, i,
906 BITMAP_PAGE_NEEDWRITE);
907 if (dirty || need_write) {
908 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
909 write_page(bitmap, bitmap->storage.filemap[i], 0);
910 }
911 if (dirty)
912 wait = 1;
913 }
914 if (wait) { /* if any writes were performed, we need to wait on them */
915 if (bitmap->storage.file)
916 wait_event(bitmap->write_wait,
917 atomic_read(&bitmap->pending_writes)==0);
918 else
919 md_super_wait(bitmap->mddev);
920 }
921 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
922 bitmap_file_kick(bitmap);
923}
924EXPORT_SYMBOL(bitmap_unplug);
925
926static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
927/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
928 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
929 * memory mapping of the bitmap file
930 * Special cases:
931 * if there's no bitmap file, or if the bitmap file had been
932 * previously kicked from the array, we mark all the bits as
933 * 1's in order to cause a full resync.
934 *
935 * We ignore all bits for sectors that end earlier than 'start'.
936 * This is used when reading an out-of-date bitmap...
937 */
938static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
939{
940 unsigned long i, chunks, index, oldindex, bit;
941 struct page *page = NULL;
942 unsigned long bit_cnt = 0;
943 struct file *file;
944 unsigned long offset;
945 int outofdate;
946 int ret = -ENOSPC;
947 void *paddr;
948 struct bitmap_storage *store = &bitmap->storage;
949
950 chunks = bitmap->counts.chunks;
951 file = store->file;
952
953 if (!file && !bitmap->mddev->bitmap_info.offset) {
954 /* No permanent bitmap - fill with '1s'. */
955 store->filemap = NULL;
956 store->file_pages = 0;
957 for (i = 0; i < chunks ; i++) {
958 /* if the disk bit is set, set the memory bit */
959 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
960 >= start);
961 bitmap_set_memory_bits(bitmap,
962 (sector_t)i << bitmap->counts.chunkshift,
963 needed);
964 }
965 return 0;
966 }
967
968 outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
969 if (outofdate)
970 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
971 "recovery\n", bmname(bitmap));
972
973 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
974 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
975 bmname(bitmap),
976 (unsigned long) i_size_read(file->f_mapping->host),
977 store->bytes);
978 goto err;
979 }
980
981 oldindex = ~0L;
982 offset = 0;
983 if (!bitmap->mddev->bitmap_info.external)
984 offset = sizeof(bitmap_super_t);
985
986 for (i = 0; i < chunks; i++) {
987 int b;
988 index = file_page_index(&bitmap->storage, i);
989 bit = file_page_offset(&bitmap->storage, i);
990 if (index != oldindex) { /* this is a new page, read it in */
991 int count;
992 /* unmap the old page, we're done with it */
993 if (index == store->file_pages-1)
994 count = store->bytes - index * PAGE_SIZE;
995 else
996 count = PAGE_SIZE;
997 page = store->filemap[index];
998 if (file)
999 ret = read_page(file, index, bitmap,
1000 count, page);
1001 else
1002 ret = read_sb_page(
1003 bitmap->mddev,
1004 bitmap->mddev->bitmap_info.offset,
1005 page,
1006 index, count);
1007
1008 if (ret)
1009 goto err;
1010
1011 oldindex = index;
1012
1013 if (outofdate) {
1014 /*
1015 * if bitmap is out of date, dirty the
1016 * whole page and write it out
1017 */
1018 paddr = kmap_atomic(page);
1019 memset(paddr + offset, 0xff,
1020 PAGE_SIZE - offset);
1021 kunmap_atomic(paddr);
1022 write_page(bitmap, page, 1);
1023
1024 ret = -EIO;
1025 if (test_bit(BITMAP_WRITE_ERROR,
1026 &bitmap->flags))
1027 goto err;
1028 }
1029 }
1030 paddr = kmap_atomic(page);
1031 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1032 b = test_bit(bit, paddr);
1033 else
1034 b = test_bit_le(bit, paddr);
1035 kunmap_atomic(paddr);
1036 if (b) {
1037 /* if the disk bit is set, set the memory bit */
1038 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1039 >= start);
1040 bitmap_set_memory_bits(bitmap,
1041 (sector_t)i << bitmap->counts.chunkshift,
1042 needed);
1043 bit_cnt++;
1044 }
1045 offset = 0;
1046 }
1047
1048 printk(KERN_INFO "%s: bitmap initialized from disk: "
1049 "read %lu pages, set %lu of %lu bits\n",
1050 bmname(bitmap), store->file_pages,
1051 bit_cnt, chunks);
1052
1053 return 0;
1054
1055 err:
1056 printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1057 bmname(bitmap), ret);
1058 return ret;
1059}
1060
1061void bitmap_write_all(struct bitmap *bitmap)
1062{
1063 /* We don't actually write all bitmap blocks here,
1064 * just flag them as needing to be written
1065 */
1066 int i;
1067
1068 if (!bitmap || !bitmap->storage.filemap)
1069 return;
1070 if (bitmap->storage.file)
1071 /* Only one copy, so nothing needed */
1072 return;
1073
1074 for (i = 0; i < bitmap->storage.file_pages; i++)
1075 set_page_attr(bitmap, i,
1076 BITMAP_PAGE_NEEDWRITE);
1077 bitmap->allclean = 0;
1078}
1079
1080static void bitmap_count_page(struct bitmap_counts *bitmap,
1081 sector_t offset, int inc)
1082{
1083 sector_t chunk = offset >> bitmap->chunkshift;
1084 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1085 bitmap->bp[page].count += inc;
1086 bitmap_checkfree(bitmap, page);
1087}
1088
1089static void bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1090{
1091 sector_t chunk = offset >> bitmap->chunkshift;
1092 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1093 struct bitmap_page *bp = &bitmap->bp[page];
1094
1095 if (!bp->pending)
1096 bp->pending = 1;
1097}
1098
1099static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
1100 sector_t offset, sector_t *blocks,
1101 int create);
1102
1103/*
1104 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1105 * out to disk
1106 */
1107
1108void bitmap_daemon_work(struct mddev *mddev)
1109{
1110 struct bitmap *bitmap;
1111 unsigned long j;
1112 unsigned long nextpage;
1113 sector_t blocks;
1114 struct bitmap_counts *counts;
1115
1116 /* Use a mutex to guard daemon_work against
1117 * bitmap_destroy.
1118 */
1119 mutex_lock(&mddev->bitmap_info.mutex);
1120 bitmap = mddev->bitmap;
1121 if (bitmap == NULL) {
1122 mutex_unlock(&mddev->bitmap_info.mutex);
1123 return;
1124 }
1125 if (time_before(jiffies, bitmap->daemon_lastrun
1126 + mddev->bitmap_info.daemon_sleep))
1127 goto done;
1128
1129 bitmap->daemon_lastrun = jiffies;
1130 if (bitmap->allclean) {
1131 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1132 goto done;
1133 }
1134 bitmap->allclean = 1;
1135
1136 /* Any file-page which is PENDING now needs to be written.
1137 * So set NEEDWRITE now, then after we make any last-minute changes
1138 * we will write it.
1139 */
1140 for (j = 0; j < bitmap->storage.file_pages; j++)
1141 if (test_and_clear_page_attr(bitmap, j,
1142 BITMAP_PAGE_PENDING))
1143 set_page_attr(bitmap, j,
1144 BITMAP_PAGE_NEEDWRITE);
1145
1146 if (bitmap->need_sync &&
1147 mddev->bitmap_info.external == 0) {
1148 /* Arrange for superblock update as well as
1149 * other changes */
1150 bitmap_super_t *sb;
1151 bitmap->need_sync = 0;
1152 if (bitmap->storage.filemap) {
1153 sb = kmap_atomic(bitmap->storage.sb_page);
1154 sb->events_cleared =
1155 cpu_to_le64(bitmap->events_cleared);
1156 kunmap_atomic(sb);
1157 set_page_attr(bitmap, 0,
1158 BITMAP_PAGE_NEEDWRITE);
1159 }
1160 }
1161 /* Now look at the bitmap counters and if any are '2' or '1',
1162 * decrement and handle accordingly.
1163 */
1164 counts = &bitmap->counts;
1165 spin_lock_irq(&counts->lock);
1166 nextpage = 0;
1167 for (j = 0; j < counts->chunks; j++) {
1168 bitmap_counter_t *bmc;
1169 sector_t block = (sector_t)j << counts->chunkshift;
1170
1171 if (j == nextpage) {
1172 nextpage += PAGE_COUNTER_RATIO;
1173 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1174 j |= PAGE_COUNTER_MASK;
1175 continue;
1176 }
1177 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1178 }
1179 bmc = bitmap_get_counter(counts,
1180 block,
1181 &blocks, 0);
1182
1183 if (!bmc) {
1184 j |= PAGE_COUNTER_MASK;
1185 continue;
1186 }
1187 if (*bmc == 1 && !bitmap->need_sync) {
1188 /* We can clear the bit */
1189 *bmc = 0;
1190 bitmap_count_page(counts, block, -1);
1191 bitmap_file_clear_bit(bitmap, block);
1192 } else if (*bmc && *bmc <= 2) {
1193 *bmc = 1;
1194 bitmap_set_pending(counts, block);
1195 bitmap->allclean = 0;
1196 }
1197 }
1198 spin_unlock_irq(&counts->lock);
1199
1200 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1201 * DIRTY pages need to be written by bitmap_unplug so it can wait
1202 * for them.
1203 * If we find any DIRTY page we stop there and let bitmap_unplug
1204 * handle all the rest. This is important in the case where
1205 * the first blocking holds the superblock and it has been updated.
1206 * We mustn't write any other blocks before the superblock.
1207 */
1208 for (j = 0;
1209 j < bitmap->storage.file_pages
1210 && !test_bit(BITMAP_STALE, &bitmap->flags);
1211 j++) {
1212
1213 if (test_page_attr(bitmap, j,
1214 BITMAP_PAGE_DIRTY))
1215 /* bitmap_unplug will handle the rest */
1216 break;
1217 if (test_and_clear_page_attr(bitmap, j,
1218 BITMAP_PAGE_NEEDWRITE)) {
1219 write_page(bitmap, bitmap->storage.filemap[j], 0);
1220 }
1221 }
1222
1223 done:
1224 if (bitmap->allclean == 0)
1225 mddev->thread->timeout =
1226 mddev->bitmap_info.daemon_sleep;
1227 mutex_unlock(&mddev->bitmap_info.mutex);
1228}
1229
1230static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
1231 sector_t offset, sector_t *blocks,
1232 int create)
1233__releases(bitmap->lock)
1234__acquires(bitmap->lock)
1235{
1236 /* If 'create', we might release the lock and reclaim it.
1237 * The lock must have been taken with interrupts enabled.
1238 * If !create, we don't release the lock.
1239 */
1240 sector_t chunk = offset >> bitmap->chunkshift;
1241 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1242 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1243 sector_t csize;
1244 int err;
1245
1246 err = bitmap_checkpage(bitmap, page, create);
1247
1248 if (bitmap->bp[page].hijacked ||
1249 bitmap->bp[page].map == NULL)
1250 csize = ((sector_t)1) << (bitmap->chunkshift +
1251 PAGE_COUNTER_SHIFT - 1);
1252 else
1253 csize = ((sector_t)1) << bitmap->chunkshift;
1254 *blocks = csize - (offset & (csize - 1));
1255
1256 if (err < 0)
1257 return NULL;
1258
1259 /* now locked ... */
1260
1261 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1262 /* should we use the first or second counter field
1263 * of the hijacked pointer? */
1264 int hi = (pageoff > PAGE_COUNTER_MASK);
1265 return &((bitmap_counter_t *)
1266 &bitmap->bp[page].map)[hi];
1267 } else /* page is allocated */
1268 return (bitmap_counter_t *)
1269 &(bitmap->bp[page].map[pageoff]);
1270}
1271
1272int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1273{
1274 if (!bitmap)
1275 return 0;
1276
1277 if (behind) {
1278 int bw;
1279 atomic_inc(&bitmap->behind_writes);
1280 bw = atomic_read(&bitmap->behind_writes);
1281 if (bw > bitmap->behind_writes_used)
1282 bitmap->behind_writes_used = bw;
1283
1284 pr_debug("inc write-behind count %d/%lu\n",
1285 bw, bitmap->mddev->bitmap_info.max_write_behind);
1286 }
1287
1288 while (sectors) {
1289 sector_t blocks;
1290 bitmap_counter_t *bmc;
1291
1292 spin_lock_irq(&bitmap->counts.lock);
1293 bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1294 if (!bmc) {
1295 spin_unlock_irq(&bitmap->counts.lock);
1296 return 0;
1297 }
1298
1299 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1300 DEFINE_WAIT(__wait);
1301 /* note that it is safe to do the prepare_to_wait
1302 * after the test as long as we do it before dropping
1303 * the spinlock.
1304 */
1305 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1306 TASK_UNINTERRUPTIBLE);
1307 spin_unlock_irq(&bitmap->counts.lock);
1308 io_schedule();
1309 finish_wait(&bitmap->overflow_wait, &__wait);
1310 continue;
1311 }
1312
1313 switch (*bmc) {
1314 case 0:
1315 bitmap_file_set_bit(bitmap, offset);
1316 bitmap_count_page(&bitmap->counts, offset, 1);
1317 /* fall through */
1318 case 1:
1319 *bmc = 2;
1320 }
1321
1322 (*bmc)++;
1323
1324 spin_unlock_irq(&bitmap->counts.lock);
1325
1326 offset += blocks;
1327 if (sectors > blocks)
1328 sectors -= blocks;
1329 else
1330 sectors = 0;
1331 }
1332 return 0;
1333}
1334EXPORT_SYMBOL(bitmap_startwrite);
1335
1336void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1337 int success, int behind)
1338{
1339 if (!bitmap)
1340 return;
1341 if (behind) {
1342 if (atomic_dec_and_test(&bitmap->behind_writes))
1343 wake_up(&bitmap->behind_wait);
1344 pr_debug("dec write-behind count %d/%lu\n",
1345 atomic_read(&bitmap->behind_writes),
1346 bitmap->mddev->bitmap_info.max_write_behind);
1347 }
1348
1349 while (sectors) {
1350 sector_t blocks;
1351 unsigned long flags;
1352 bitmap_counter_t *bmc;
1353
1354 spin_lock_irqsave(&bitmap->counts.lock, flags);
1355 bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1356 if (!bmc) {
1357 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1358 return;
1359 }
1360
1361 if (success && !bitmap->mddev->degraded &&
1362 bitmap->events_cleared < bitmap->mddev->events) {
1363 bitmap->events_cleared = bitmap->mddev->events;
1364 bitmap->need_sync = 1;
1365 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1366 }
1367
1368 if (!success && !NEEDED(*bmc))
1369 *bmc |= NEEDED_MASK;
1370
1371 if (COUNTER(*bmc) == COUNTER_MAX)
1372 wake_up(&bitmap->overflow_wait);
1373
1374 (*bmc)--;
1375 if (*bmc <= 2) {
1376 bitmap_set_pending(&bitmap->counts, offset);
1377 bitmap->allclean = 0;
1378 }
1379 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1380 offset += blocks;
1381 if (sectors > blocks)
1382 sectors -= blocks;
1383 else
1384 sectors = 0;
1385 }
1386}
1387EXPORT_SYMBOL(bitmap_endwrite);
1388
1389static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1390 int degraded)
1391{
1392 bitmap_counter_t *bmc;
1393 int rv;
1394 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1395 *blocks = 1024;
1396 return 1; /* always resync if no bitmap */
1397 }
1398 spin_lock_irq(&bitmap->counts.lock);
1399 bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1400 rv = 0;
1401 if (bmc) {
1402 /* locked */
1403 if (RESYNC(*bmc))
1404 rv = 1;
1405 else if (NEEDED(*bmc)) {
1406 rv = 1;
1407 if (!degraded) { /* don't set/clear bits if degraded */
1408 *bmc |= RESYNC_MASK;
1409 *bmc &= ~NEEDED_MASK;
1410 }
1411 }
1412 }
1413 spin_unlock_irq(&bitmap->counts.lock);
1414 return rv;
1415}
1416
1417int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1418 int degraded)
1419{
1420 /* bitmap_start_sync must always report on multiples of whole
1421 * pages, otherwise resync (which is very PAGE_SIZE based) will
1422 * get confused.
1423 * So call __bitmap_start_sync repeatedly (if needed) until
1424 * At least PAGE_SIZE>>9 blocks are covered.
1425 * Return the 'or' of the result.
1426 */
1427 int rv = 0;
1428 sector_t blocks1;
1429
1430 *blocks = 0;
1431 while (*blocks < (PAGE_SIZE>>9)) {
1432 rv |= __bitmap_start_sync(bitmap, offset,
1433 &blocks1, degraded);
1434 offset += blocks1;
1435 *blocks += blocks1;
1436 }
1437 return rv;
1438}
1439EXPORT_SYMBOL(bitmap_start_sync);
1440
1441void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1442{
1443 bitmap_counter_t *bmc;
1444 unsigned long flags;
1445
1446 if (bitmap == NULL) {
1447 *blocks = 1024;
1448 return;
1449 }
1450 spin_lock_irqsave(&bitmap->counts.lock, flags);
1451 bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1452 if (bmc == NULL)
1453 goto unlock;
1454 /* locked */
1455 if (RESYNC(*bmc)) {
1456 *bmc &= ~RESYNC_MASK;
1457
1458 if (!NEEDED(*bmc) && aborted)
1459 *bmc |= NEEDED_MASK;
1460 else {
1461 if (*bmc <= 2) {
1462 bitmap_set_pending(&bitmap->counts, offset);
1463 bitmap->allclean = 0;
1464 }
1465 }
1466 }
1467 unlock:
1468 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1469}
1470EXPORT_SYMBOL(bitmap_end_sync);
1471
1472void bitmap_close_sync(struct bitmap *bitmap)
1473{
1474 /* Sync has finished, and any bitmap chunks that weren't synced
1475 * properly have been aborted. It remains to us to clear the
1476 * RESYNC bit wherever it is still on
1477 */
1478 sector_t sector = 0;
1479 sector_t blocks;
1480 if (!bitmap)
1481 return;
1482 while (sector < bitmap->mddev->resync_max_sectors) {
1483 bitmap_end_sync(bitmap, sector, &blocks, 0);
1484 sector += blocks;
1485 }
1486}
1487EXPORT_SYMBOL(bitmap_close_sync);
1488
1489void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
1490{
1491 sector_t s = 0;
1492 sector_t blocks;
1493
1494 if (!bitmap)
1495 return;
1496 if (sector == 0) {
1497 bitmap->last_end_sync = jiffies;
1498 return;
1499 }
1500 if (time_before(jiffies, (bitmap->last_end_sync
1501 + bitmap->mddev->bitmap_info.daemon_sleep)))
1502 return;
1503 wait_event(bitmap->mddev->recovery_wait,
1504 atomic_read(&bitmap->mddev->recovery_active) == 0);
1505
1506 bitmap->mddev->curr_resync_completed = sector;
1507 set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1508 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1509 s = 0;
1510 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1511 bitmap_end_sync(bitmap, s, &blocks, 0);
1512 s += blocks;
1513 }
1514 bitmap->last_end_sync = jiffies;
1515 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1516}
1517EXPORT_SYMBOL(bitmap_cond_end_sync);
1518
1519static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1520{
1521 /* For each chunk covered by any of these sectors, set the
1522 * counter to 2 and possibly set resync_needed. They should all
1523 * be 0 at this point
1524 */
1525
1526 sector_t secs;
1527 bitmap_counter_t *bmc;
1528 spin_lock_irq(&bitmap->counts.lock);
1529 bmc = bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1530 if (!bmc) {
1531 spin_unlock_irq(&bitmap->counts.lock);
1532 return;
1533 }
1534 if (!*bmc) {
1535 *bmc = 2 | (needed ? NEEDED_MASK : 0);
1536 bitmap_count_page(&bitmap->counts, offset, 1);
1537 bitmap_set_pending(&bitmap->counts, offset);
1538 bitmap->allclean = 0;
1539 }
1540 spin_unlock_irq(&bitmap->counts.lock);
1541}
1542
1543/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1544void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1545{
1546 unsigned long chunk;
1547
1548 for (chunk = s; chunk <= e; chunk++) {
1549 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1550 bitmap_set_memory_bits(bitmap, sec, 1);
1551 bitmap_file_set_bit(bitmap, sec);
1552 if (sec < bitmap->mddev->recovery_cp)
1553 /* We are asserting that the array is dirty,
1554 * so move the recovery_cp address back so
1555 * that it is obvious that it is dirty
1556 */
1557 bitmap->mddev->recovery_cp = sec;
1558 }
1559}
1560
1561/*
1562 * flush out any pending updates
1563 */
1564void bitmap_flush(struct mddev *mddev)
1565{
1566 struct bitmap *bitmap = mddev->bitmap;
1567 long sleep;
1568
1569 if (!bitmap) /* there was no bitmap */
1570 return;
1571
1572 /* run the daemon_work three time to ensure everything is flushed
1573 * that can be
1574 */
1575 sleep = mddev->bitmap_info.daemon_sleep * 2;
1576 bitmap->daemon_lastrun -= sleep;
1577 bitmap_daemon_work(mddev);
1578 bitmap->daemon_lastrun -= sleep;
1579 bitmap_daemon_work(mddev);
1580 bitmap->daemon_lastrun -= sleep;
1581 bitmap_daemon_work(mddev);
1582 bitmap_update_sb(bitmap);
1583}
1584
1585/*
1586 * free memory that was allocated
1587 */
1588static void bitmap_free(struct bitmap *bitmap)
1589{
1590 unsigned long k, pages;
1591 struct bitmap_page *bp;
1592
1593 if (!bitmap) /* there was no bitmap */
1594 return;
1595
1596 /* Shouldn't be needed - but just in case.... */
1597 wait_event(bitmap->write_wait,
1598 atomic_read(&bitmap->pending_writes) == 0);
1599
1600 /* release the bitmap file */
1601 bitmap_file_unmap(&bitmap->storage);
1602
1603 bp = bitmap->counts.bp;
1604 pages = bitmap->counts.pages;
1605
1606 /* free all allocated memory */
1607
1608 if (bp) /* deallocate the page memory */
1609 for (k = 0; k < pages; k++)
1610 if (bp[k].map && !bp[k].hijacked)
1611 kfree(bp[k].map);
1612 kfree(bp);
1613 kfree(bitmap);
1614}
1615
1616void bitmap_destroy(struct mddev *mddev)
1617{
1618 struct bitmap *bitmap = mddev->bitmap;
1619
1620 if (!bitmap) /* there was no bitmap */
1621 return;
1622
1623 mutex_lock(&mddev->bitmap_info.mutex);
1624 mddev->bitmap = NULL; /* disconnect from the md device */
1625 mutex_unlock(&mddev->bitmap_info.mutex);
1626 if (mddev->thread)
1627 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1628
1629 if (bitmap->sysfs_can_clear)
1630 sysfs_put(bitmap->sysfs_can_clear);
1631
1632 bitmap_free(bitmap);
1633}
1634
1635/*
1636 * initialize the bitmap structure
1637 * if this returns an error, bitmap_destroy must be called to do clean up
1638 */
1639int bitmap_create(struct mddev *mddev)
1640{
1641 struct bitmap *bitmap;
1642 sector_t blocks = mddev->resync_max_sectors;
1643 struct file *file = mddev->bitmap_info.file;
1644 int err;
1645 struct sysfs_dirent *bm = NULL;
1646
1647 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1648
1649 BUG_ON(file && mddev->bitmap_info.offset);
1650
1651 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1652 if (!bitmap)
1653 return -ENOMEM;
1654
1655 spin_lock_init(&bitmap->counts.lock);
1656 atomic_set(&bitmap->pending_writes, 0);
1657 init_waitqueue_head(&bitmap->write_wait);
1658 init_waitqueue_head(&bitmap->overflow_wait);
1659 init_waitqueue_head(&bitmap->behind_wait);
1660
1661 bitmap->mddev = mddev;
1662
1663 if (mddev->kobj.sd)
1664 bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap");
1665 if (bm) {
1666 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear");
1667 sysfs_put(bm);
1668 } else
1669 bitmap->sysfs_can_clear = NULL;
1670
1671 bitmap->storage.file = file;
1672 if (file) {
1673 get_file(file);
1674 /* As future accesses to this file will use bmap,
1675 * and bypass the page cache, we must sync the file
1676 * first.
1677 */
1678 vfs_fsync(file, 1);
1679 }
1680 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1681 if (!mddev->bitmap_info.external) {
1682 /*
1683 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1684 * instructing us to create a new on-disk bitmap instance.
1685 */
1686 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1687 err = bitmap_new_disk_sb(bitmap);
1688 else
1689 err = bitmap_read_sb(bitmap);
1690 } else {
1691 err = 0;
1692 if (mddev->bitmap_info.chunksize == 0 ||
1693 mddev->bitmap_info.daemon_sleep == 0)
1694 /* chunksize and time_base need to be
1695 * set first. */
1696 err = -EINVAL;
1697 }
1698 if (err)
1699 goto error;
1700
1701 bitmap->daemon_lastrun = jiffies;
1702 err = bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1703 if (err)
1704 goto error;
1705
1706 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1707 bitmap->counts.pages, bmname(bitmap));
1708
1709 mddev->bitmap = bitmap;
1710 return test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1711
1712 error:
1713 bitmap_free(bitmap);
1714 return err;
1715}
1716
1717int bitmap_load(struct mddev *mddev)
1718{
1719 int err = 0;
1720 sector_t start = 0;
1721 sector_t sector = 0;
1722 struct bitmap *bitmap = mddev->bitmap;
1723
1724 if (!bitmap)
1725 goto out;
1726
1727 /* Clear out old bitmap info first: Either there is none, or we
1728 * are resuming after someone else has possibly changed things,
1729 * so we should forget old cached info.
1730 * All chunks should be clean, but some might need_sync.
1731 */
1732 while (sector < mddev->resync_max_sectors) {
1733 sector_t blocks;
1734 bitmap_start_sync(bitmap, sector, &blocks, 0);
1735 sector += blocks;
1736 }
1737 bitmap_close_sync(bitmap);
1738
1739 if (mddev->degraded == 0
1740 || bitmap->events_cleared == mddev->events)
1741 /* no need to keep dirty bits to optimise a
1742 * re-add of a missing device */
1743 start = mddev->recovery_cp;
1744
1745 mutex_lock(&mddev->bitmap_info.mutex);
1746 err = bitmap_init_from_disk(bitmap, start);
1747 mutex_unlock(&mddev->bitmap_info.mutex);
1748
1749 if (err)
1750 goto out;
1751 clear_bit(BITMAP_STALE, &bitmap->flags);
1752
1753 /* Kick recovery in case any bits were set */
1754 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1755
1756 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1757 md_wakeup_thread(mddev->thread);
1758
1759 bitmap_update_sb(bitmap);
1760
1761 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1762 err = -EIO;
1763out:
1764 return err;
1765}
1766EXPORT_SYMBOL_GPL(bitmap_load);
1767
1768void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
1769{
1770 unsigned long chunk_kb;
1771 struct bitmap_counts *counts;
1772
1773 if (!bitmap)
1774 return;
1775
1776 counts = &bitmap->counts;
1777
1778 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
1779 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
1780 "%lu%s chunk",
1781 counts->pages - counts->missing_pages,
1782 counts->pages,
1783 (counts->pages - counts->missing_pages)
1784 << (PAGE_SHIFT - 10),
1785 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
1786 chunk_kb ? "KB" : "B");
1787 if (bitmap->storage.file) {
1788 seq_printf(seq, ", file: ");
1789 seq_path(seq, &bitmap->storage.file->f_path, " \t\n");
1790 }
1791
1792 seq_printf(seq, "\n");
1793}
1794
1795int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
1796 int chunksize, int init)
1797{
1798 /* If chunk_size is 0, choose an appropriate chunk size.
1799 * Then possibly allocate new storage space.
1800 * Then quiesce, copy bits, replace bitmap, and re-start
1801 *
1802 * This function is called both to set up the initial bitmap
1803 * and to resize the bitmap while the array is active.
1804 * If this happens as a result of the array being resized,
1805 * chunksize will be zero, and we need to choose a suitable
1806 * chunksize, otherwise we use what we are given.
1807 */
1808 struct bitmap_storage store;
1809 struct bitmap_counts old_counts;
1810 unsigned long chunks;
1811 sector_t block;
1812 sector_t old_blocks, new_blocks;
1813 int chunkshift;
1814 int ret = 0;
1815 long pages;
1816 struct bitmap_page *new_bp;
1817
1818 if (chunksize == 0) {
1819 /* If there is enough space, leave the chunk size unchanged,
1820 * else increase by factor of two until there is enough space.
1821 */
1822 long bytes;
1823 long space = bitmap->mddev->bitmap_info.space;
1824
1825 if (space == 0) {
1826 /* We don't know how much space there is, so limit
1827 * to current size - in sectors.
1828 */
1829 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
1830 if (!bitmap->mddev->bitmap_info.external)
1831 bytes += sizeof(bitmap_super_t);
1832 space = DIV_ROUND_UP(bytes, 512);
1833 bitmap->mddev->bitmap_info.space = space;
1834 }
1835 chunkshift = bitmap->counts.chunkshift;
1836 chunkshift--;
1837 do {
1838 /* 'chunkshift' is shift from block size to chunk size */
1839 chunkshift++;
1840 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
1841 bytes = DIV_ROUND_UP(chunks, 8);
1842 if (!bitmap->mddev->bitmap_info.external)
1843 bytes += sizeof(bitmap_super_t);
1844 } while (bytes > (space << 9));
1845 } else
1846 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
1847
1848 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
1849 memset(&store, 0, sizeof(store));
1850 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
1851 ret = bitmap_storage_alloc(&store, chunks,
1852 !bitmap->mddev->bitmap_info.external);
1853 if (ret)
1854 goto err;
1855
1856 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
1857
1858 new_bp = kzalloc(pages * sizeof(*new_bp), GFP_KERNEL);
1859 ret = -ENOMEM;
1860 if (!new_bp) {
1861 bitmap_file_unmap(&store);
1862 goto err;
1863 }
1864
1865 if (!init)
1866 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
1867
1868 store.file = bitmap->storage.file;
1869 bitmap->storage.file = NULL;
1870
1871 if (store.sb_page && bitmap->storage.sb_page)
1872 memcpy(page_address(store.sb_page),
1873 page_address(bitmap->storage.sb_page),
1874 sizeof(bitmap_super_t));
1875 bitmap_file_unmap(&bitmap->storage);
1876 bitmap->storage = store;
1877
1878 old_counts = bitmap->counts;
1879 bitmap->counts.bp = new_bp;
1880 bitmap->counts.pages = pages;
1881 bitmap->counts.missing_pages = pages;
1882 bitmap->counts.chunkshift = chunkshift;
1883 bitmap->counts.chunks = chunks;
1884 bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift +
1885 BITMAP_BLOCK_SHIFT);
1886
1887 blocks = min(old_counts.chunks << old_counts.chunkshift,
1888 chunks << chunkshift);
1889
1890 spin_lock_irq(&bitmap->counts.lock);
1891 for (block = 0; block < blocks; ) {
1892 bitmap_counter_t *bmc_old, *bmc_new;
1893 int set;
1894
1895 bmc_old = bitmap_get_counter(&old_counts, block,
1896 &old_blocks, 0);
1897 set = bmc_old && NEEDED(*bmc_old);
1898
1899 if (set) {
1900 bmc_new = bitmap_get_counter(&bitmap->counts, block,
1901 &new_blocks, 1);
1902 if (*bmc_new == 0) {
1903 /* need to set on-disk bits too. */
1904 sector_t end = block + new_blocks;
1905 sector_t start = block >> chunkshift;
1906 start <<= chunkshift;
1907 while (start < end) {
1908 bitmap_file_set_bit(bitmap, block);
1909 start += 1 << chunkshift;
1910 }
1911 *bmc_new = 2;
1912 bitmap_count_page(&bitmap->counts,
1913 block, 1);
1914 bitmap_set_pending(&bitmap->counts,
1915 block);
1916 }
1917 *bmc_new |= NEEDED_MASK;
1918 if (new_blocks < old_blocks)
1919 old_blocks = new_blocks;
1920 }
1921 block += old_blocks;
1922 }
1923
1924 if (!init) {
1925 int i;
1926 while (block < (chunks << chunkshift)) {
1927 bitmap_counter_t *bmc;
1928 bmc = bitmap_get_counter(&bitmap->counts, block,
1929 &new_blocks, 1);
1930 if (bmc) {
1931 /* new space. It needs to be resynced, so
1932 * we set NEEDED_MASK.
1933 */
1934 if (*bmc == 0) {
1935 *bmc = NEEDED_MASK | 2;
1936 bitmap_count_page(&bitmap->counts,
1937 block, 1);
1938 bitmap_set_pending(&bitmap->counts,
1939 block);
1940 }
1941 }
1942 block += new_blocks;
1943 }
1944 for (i = 0; i < bitmap->storage.file_pages; i++)
1945 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1946 }
1947 spin_unlock_irq(&bitmap->counts.lock);
1948
1949 if (!init) {
1950 bitmap_unplug(bitmap);
1951 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
1952 }
1953 ret = 0;
1954err:
1955 return ret;
1956}
1957EXPORT_SYMBOL_GPL(bitmap_resize);
1958
1959static ssize_t
1960location_show(struct mddev *mddev, char *page)
1961{
1962 ssize_t len;
1963 if (mddev->bitmap_info.file)
1964 len = sprintf(page, "file");
1965 else if (mddev->bitmap_info.offset)
1966 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
1967 else
1968 len = sprintf(page, "none");
1969 len += sprintf(page+len, "\n");
1970 return len;
1971}
1972
1973static ssize_t
1974location_store(struct mddev *mddev, const char *buf, size_t len)
1975{
1976
1977 if (mddev->pers) {
1978 if (!mddev->pers->quiesce)
1979 return -EBUSY;
1980 if (mddev->recovery || mddev->sync_thread)
1981 return -EBUSY;
1982 }
1983
1984 if (mddev->bitmap || mddev->bitmap_info.file ||
1985 mddev->bitmap_info.offset) {
1986 /* bitmap already configured. Only option is to clear it */
1987 if (strncmp(buf, "none", 4) != 0)
1988 return -EBUSY;
1989 if (mddev->pers) {
1990 mddev->pers->quiesce(mddev, 1);
1991 bitmap_destroy(mddev);
1992 mddev->pers->quiesce(mddev, 0);
1993 }
1994 mddev->bitmap_info.offset = 0;
1995 if (mddev->bitmap_info.file) {
1996 struct file *f = mddev->bitmap_info.file;
1997 mddev->bitmap_info.file = NULL;
1998 restore_bitmap_write_access(f);
1999 fput(f);
2000 }
2001 } else {
2002 /* No bitmap, OK to set a location */
2003 long long offset;
2004 if (strncmp(buf, "none", 4) == 0)
2005 /* nothing to be done */;
2006 else if (strncmp(buf, "file:", 5) == 0) {
2007 /* Not supported yet */
2008 return -EINVAL;
2009 } else {
2010 int rv;
2011 if (buf[0] == '+')
2012 rv = strict_strtoll(buf+1, 10, &offset);
2013 else
2014 rv = strict_strtoll(buf, 10, &offset);
2015 if (rv)
2016 return rv;
2017 if (offset == 0)
2018 return -EINVAL;
2019 if (mddev->bitmap_info.external == 0 &&
2020 mddev->major_version == 0 &&
2021 offset != mddev->bitmap_info.default_offset)
2022 return -EINVAL;
2023 mddev->bitmap_info.offset = offset;
2024 if (mddev->pers) {
2025 mddev->pers->quiesce(mddev, 1);
2026 rv = bitmap_create(mddev);
2027 if (!rv)
2028 rv = bitmap_load(mddev);
2029 if (rv) {
2030 bitmap_destroy(mddev);
2031 mddev->bitmap_info.offset = 0;
2032 }
2033 mddev->pers->quiesce(mddev, 0);
2034 if (rv)
2035 return rv;
2036 }
2037 }
2038 }
2039 if (!mddev->external) {
2040 /* Ensure new bitmap info is stored in
2041 * metadata promptly.
2042 */
2043 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2044 md_wakeup_thread(mddev->thread);
2045 }
2046 return len;
2047}
2048
2049static struct md_sysfs_entry bitmap_location =
2050__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2051
2052/* 'bitmap/space' is the space available at 'location' for the
2053 * bitmap. This allows the kernel to know when it is safe to
2054 * resize the bitmap to match a resized array.
2055 */
2056static ssize_t
2057space_show(struct mddev *mddev, char *page)
2058{
2059 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2060}
2061
2062static ssize_t
2063space_store(struct mddev *mddev, const char *buf, size_t len)
2064{
2065 unsigned long sectors;
2066 int rv;
2067
2068 rv = kstrtoul(buf, 10, §ors);
2069 if (rv)
2070 return rv;
2071
2072 if (sectors == 0)
2073 return -EINVAL;
2074
2075 if (mddev->bitmap &&
2076 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2077 return -EFBIG; /* Bitmap is too big for this small space */
2078
2079 /* could make sure it isn't too big, but that isn't really
2080 * needed - user-space should be careful.
2081 */
2082 mddev->bitmap_info.space = sectors;
2083 return len;
2084}
2085
2086static struct md_sysfs_entry bitmap_space =
2087__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2088
2089static ssize_t
2090timeout_show(struct mddev *mddev, char *page)
2091{
2092 ssize_t len;
2093 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2094 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2095
2096 len = sprintf(page, "%lu", secs);
2097 if (jifs)
2098 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2099 len += sprintf(page+len, "\n");
2100 return len;
2101}
2102
2103static ssize_t
2104timeout_store(struct mddev *mddev, const char *buf, size_t len)
2105{
2106 /* timeout can be set at any time */
2107 unsigned long timeout;
2108 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2109 if (rv)
2110 return rv;
2111
2112 /* just to make sure we don't overflow... */
2113 if (timeout >= LONG_MAX / HZ)
2114 return -EINVAL;
2115
2116 timeout = timeout * HZ / 10000;
2117
2118 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2119 timeout = MAX_SCHEDULE_TIMEOUT-1;
2120 if (timeout < 1)
2121 timeout = 1;
2122 mddev->bitmap_info.daemon_sleep = timeout;
2123 if (mddev->thread) {
2124 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
2125 * the bitmap is all clean and we don't need to
2126 * adjust the timeout right now
2127 */
2128 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2129 mddev->thread->timeout = timeout;
2130 md_wakeup_thread(mddev->thread);
2131 }
2132 }
2133 return len;
2134}
2135
2136static struct md_sysfs_entry bitmap_timeout =
2137__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2138
2139static ssize_t
2140backlog_show(struct mddev *mddev, char *page)
2141{
2142 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2143}
2144
2145static ssize_t
2146backlog_store(struct mddev *mddev, const char *buf, size_t len)
2147{
2148 unsigned long backlog;
2149 int rv = strict_strtoul(buf, 10, &backlog);
2150 if (rv)
2151 return rv;
2152 if (backlog > COUNTER_MAX)
2153 return -EINVAL;
2154 mddev->bitmap_info.max_write_behind = backlog;
2155 return len;
2156}
2157
2158static struct md_sysfs_entry bitmap_backlog =
2159__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2160
2161static ssize_t
2162chunksize_show(struct mddev *mddev, char *page)
2163{
2164 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2165}
2166
2167static ssize_t
2168chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2169{
2170 /* Can only be changed when no bitmap is active */
2171 int rv;
2172 unsigned long csize;
2173 if (mddev->bitmap)
2174 return -EBUSY;
2175 rv = strict_strtoul(buf, 10, &csize);
2176 if (rv)
2177 return rv;
2178 if (csize < 512 ||
2179 !is_power_of_2(csize))
2180 return -EINVAL;
2181 mddev->bitmap_info.chunksize = csize;
2182 return len;
2183}
2184
2185static struct md_sysfs_entry bitmap_chunksize =
2186__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2187
2188static ssize_t metadata_show(struct mddev *mddev, char *page)
2189{
2190 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2191 ? "external" : "internal"));
2192}
2193
2194static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2195{
2196 if (mddev->bitmap ||
2197 mddev->bitmap_info.file ||
2198 mddev->bitmap_info.offset)
2199 return -EBUSY;
2200 if (strncmp(buf, "external", 8) == 0)
2201 mddev->bitmap_info.external = 1;
2202 else if (strncmp(buf, "internal", 8) == 0)
2203 mddev->bitmap_info.external = 0;
2204 else
2205 return -EINVAL;
2206 return len;
2207}
2208
2209static struct md_sysfs_entry bitmap_metadata =
2210__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2211
2212static ssize_t can_clear_show(struct mddev *mddev, char *page)
2213{
2214 int len;
2215 if (mddev->bitmap)
2216 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2217 "false" : "true"));
2218 else
2219 len = sprintf(page, "\n");
2220 return len;
2221}
2222
2223static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2224{
2225 if (mddev->bitmap == NULL)
2226 return -ENOENT;
2227 if (strncmp(buf, "false", 5) == 0)
2228 mddev->bitmap->need_sync = 1;
2229 else if (strncmp(buf, "true", 4) == 0) {
2230 if (mddev->degraded)
2231 return -EBUSY;
2232 mddev->bitmap->need_sync = 0;
2233 } else
2234 return -EINVAL;
2235 return len;
2236}
2237
2238static struct md_sysfs_entry bitmap_can_clear =
2239__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2240
2241static ssize_t
2242behind_writes_used_show(struct mddev *mddev, char *page)
2243{
2244 if (mddev->bitmap == NULL)
2245 return sprintf(page, "0\n");
2246 return sprintf(page, "%lu\n",
2247 mddev->bitmap->behind_writes_used);
2248}
2249
2250static ssize_t
2251behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2252{
2253 if (mddev->bitmap)
2254 mddev->bitmap->behind_writes_used = 0;
2255 return len;
2256}
2257
2258static struct md_sysfs_entry max_backlog_used =
2259__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2260 behind_writes_used_show, behind_writes_used_reset);
2261
2262static struct attribute *md_bitmap_attrs[] = {
2263 &bitmap_location.attr,
2264 &bitmap_space.attr,
2265 &bitmap_timeout.attr,
2266 &bitmap_backlog.attr,
2267 &bitmap_chunksize.attr,
2268 &bitmap_metadata.attr,
2269 &bitmap_can_clear.attr,
2270 &max_backlog_used.attr,
2271 NULL
2272};
2273struct attribute_group md_bitmap_group = {
2274 .name = "bitmap",
2275 .attrs = md_bitmap_attrs,
2276};
2277