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