2 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
4 * bitmap_create - sets up the bitmap structure
5 * bitmap_destroy - destroys the bitmap structure
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
15 * flush after percent set rather than just time based. (maybe both).
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>
33 static inline char *bmname(struct bitmap *bitmap)
35 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
39 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
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
45 * if we find our page, we increment the page's refcount so that it stays
46 * allocated while we're using it
48 static int bitmap_checkpage(struct bitmap *bitmap,
49 unsigned long page, int create)
50 __releases(bitmap->lock)
51 __acquires(bitmap->lock)
53 unsigned char *mappage;
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.
63 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
66 if (bitmap->bp[page].map) /* page is already allocated, just return */
72 /* this page has not been allocated yet */
74 spin_unlock_irq(&bitmap->lock);
75 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
76 spin_lock_irq(&bitmap->lock);
78 if (mappage == NULL) {
79 pr_debug("%s: bitmap map page allocation failed, hijacking\n",
81 /* failed - set the hijacked flag so that we can use the
82 * pointer as a counter */
83 if (!bitmap->bp[page].map)
84 bitmap->bp[page].hijacked = 1;
85 } else if (bitmap->bp[page].map ||
86 bitmap->bp[page].hijacked) {
87 /* somebody beat us to getting the page */
92 /* no page was in place and we have one, so install it */
94 bitmap->bp[page].map = mappage;
95 bitmap->missing_pages--;
100 /* if page is completely empty, put it back on the free list, or dealloc it */
101 /* if page was hijacked, unmark the flag so it might get alloced next time */
102 /* Note: lock should be held when calling this */
103 static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
107 if (bitmap->bp[page].count) /* page is still busy */
110 /* page is no longer in use, it can be released */
112 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
113 bitmap->bp[page].hijacked = 0;
114 bitmap->bp[page].map = NULL;
116 /* normal case, free the page */
117 ptr = bitmap->bp[page].map;
118 bitmap->bp[page].map = NULL;
119 bitmap->missing_pages++;
125 * bitmap file handling - read and write the bitmap file and its superblock
129 * basic page I/O operations
132 /* IO operations when bitmap is stored near all superblocks */
133 static struct page *read_sb_page(struct mddev *mddev, loff_t offset,
135 unsigned long index, int size)
137 /* choose a good rdev and read the page from there */
139 struct md_rdev *rdev;
144 page = alloc_page(GFP_KERNEL);
146 return ERR_PTR(-ENOMEM);
150 rdev_for_each(rdev, mddev) {
151 if (! test_bit(In_sync, &rdev->flags)
152 || test_bit(Faulty, &rdev->flags))
155 target = offset + index * (PAGE_SIZE/512);
157 if (sync_page_io(rdev, target,
158 roundup(size, bdev_logical_block_size(rdev->bdev)),
161 attach_page_buffers(page, NULL); /* so that free_buffer will
168 return ERR_PTR(-EIO);
172 static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
174 /* Iterate the disks of an mddev, using rcu to protect access to the
175 * linked list, and raising the refcount of devices we return to ensure
176 * they don't disappear while in use.
177 * As devices are only added or removed when raid_disk is < 0 and
178 * nr_pending is 0 and In_sync is clear, the entries we return will
179 * still be in the same position on the list when we re-enter
180 * list_for_each_continue_rcu.
182 struct list_head *pos;
185 /* start at the beginning */
188 /* release the previous rdev and start from there. */
189 rdev_dec_pending(rdev, mddev);
190 pos = &rdev->same_set;
192 list_for_each_continue_rcu(pos, &mddev->disks) {
193 rdev = list_entry(pos, struct md_rdev, same_set);
194 if (rdev->raid_disk >= 0 &&
195 !test_bit(Faulty, &rdev->flags)) {
196 /* this is a usable devices */
197 atomic_inc(&rdev->nr_pending);
206 static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
208 struct md_rdev *rdev = NULL;
209 struct block_device *bdev;
210 struct mddev *mddev = bitmap->mddev;
212 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
213 int size = PAGE_SIZE;
214 loff_t offset = mddev->bitmap_info.offset;
216 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
218 if (page->index == bitmap->file_pages-1)
219 size = roundup(bitmap->last_page_size,
220 bdev_logical_block_size(bdev));
221 /* Just make sure we aren't corrupting data or
224 if (mddev->external) {
225 /* Bitmap could be anywhere. */
226 if (rdev->sb_start + offset + (page->index
230 rdev->sb_start + offset
231 < (rdev->data_offset + mddev->dev_sectors
234 } else if (offset < 0) {
235 /* DATA BITMAP METADATA */
237 + (long)(page->index * (PAGE_SIZE/512))
239 /* bitmap runs in to metadata */
241 if (rdev->data_offset + mddev->dev_sectors
242 > rdev->sb_start + offset)
243 /* data runs in to bitmap */
245 } else if (rdev->sb_start < rdev->data_offset) {
246 /* METADATA BITMAP DATA */
249 + page->index*(PAGE_SIZE/512) + size/512
251 /* bitmap runs in to data */
254 /* DATA METADATA BITMAP - no problems */
256 md_super_write(mddev, rdev,
257 rdev->sb_start + offset
258 + page->index * (PAGE_SIZE/512),
264 md_super_wait(mddev);
271 static void bitmap_file_kick(struct bitmap *bitmap);
273 * write out a page to a file
275 static void write_page(struct bitmap *bitmap, struct page *page, int wait)
277 struct buffer_head *bh;
279 if (bitmap->file == NULL) {
280 switch (write_sb_page(bitmap, page, wait)) {
282 bitmap->flags |= BITMAP_WRITE_ERROR;
286 bh = page_buffers(page);
288 while (bh && bh->b_blocknr) {
289 atomic_inc(&bitmap->pending_writes);
290 set_buffer_locked(bh);
291 set_buffer_mapped(bh);
292 submit_bh(WRITE | REQ_SYNC, bh);
293 bh = bh->b_this_page;
297 wait_event(bitmap->write_wait,
298 atomic_read(&bitmap->pending_writes)==0);
300 if (bitmap->flags & BITMAP_WRITE_ERROR)
301 bitmap_file_kick(bitmap);
304 static void end_bitmap_write(struct buffer_head *bh, int uptodate)
306 struct bitmap *bitmap = bh->b_private;
310 spin_lock_irqsave(&bitmap->lock, flags);
311 bitmap->flags |= BITMAP_WRITE_ERROR;
312 spin_unlock_irqrestore(&bitmap->lock, flags);
314 if (atomic_dec_and_test(&bitmap->pending_writes))
315 wake_up(&bitmap->write_wait);
318 /* copied from buffer.c */
320 __clear_page_buffers(struct page *page)
322 ClearPagePrivate(page);
323 set_page_private(page, 0);
324 page_cache_release(page);
326 static void free_buffers(struct page *page)
328 struct buffer_head *bh = page_buffers(page);
331 struct buffer_head *next = bh->b_this_page;
332 free_buffer_head(bh);
335 __clear_page_buffers(page);
339 /* read a page from a file.
340 * We both read the page, and attach buffers to the page to record the
341 * address of each block (using bmap). These addresses will be used
342 * to write the block later, completely bypassing the filesystem.
343 * This usage is similar to how swap files are handled, and allows us
344 * to write to a file with no concerns of memory allocation failing.
346 static struct page *read_page(struct file *file, unsigned long index,
347 struct bitmap *bitmap,
350 struct page *page = NULL;
351 struct inode *inode = file->f_path.dentry->d_inode;
352 struct buffer_head *bh;
355 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
356 (unsigned long long)index << PAGE_SHIFT);
358 page = alloc_page(GFP_KERNEL);
360 page = ERR_PTR(-ENOMEM);
364 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
367 page = ERR_PTR(-ENOMEM);
370 attach_page_buffers(page, bh);
371 block = index << (PAGE_SHIFT - inode->i_blkbits);
376 bh->b_blocknr = bmap(inode, block);
377 if (bh->b_blocknr == 0) {
378 /* Cannot use this file! */
380 page = ERR_PTR(-EINVAL);
383 bh->b_bdev = inode->i_sb->s_bdev;
384 if (count < (1<<inode->i_blkbits))
387 count -= (1<<inode->i_blkbits);
389 bh->b_end_io = end_bitmap_write;
390 bh->b_private = bitmap;
391 atomic_inc(&bitmap->pending_writes);
392 set_buffer_locked(bh);
393 set_buffer_mapped(bh);
397 bh = bh->b_this_page;
401 wait_event(bitmap->write_wait,
402 atomic_read(&bitmap->pending_writes)==0);
403 if (bitmap->flags & BITMAP_WRITE_ERROR) {
405 page = ERR_PTR(-EIO);
409 printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %ld\n",
411 (unsigned long long)index << PAGE_SHIFT,
417 * bitmap file superblock operations
420 /* update the event counter and sync the superblock to disk */
421 void bitmap_update_sb(struct bitmap *bitmap)
425 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
427 if (bitmap->mddev->bitmap_info.external)
429 if (!bitmap->sb_page) /* no superblock */
431 sb = kmap_atomic(bitmap->sb_page);
432 sb->events = cpu_to_le64(bitmap->mddev->events);
433 if (bitmap->mddev->events < bitmap->events_cleared)
434 /* rocking back to read-only */
435 bitmap->events_cleared = bitmap->mddev->events;
436 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
437 sb->state = cpu_to_le32(bitmap->flags);
438 /* Just in case these have been changed via sysfs: */
439 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
440 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
442 write_page(bitmap, bitmap->sb_page, 1);
445 /* print out the bitmap file superblock */
446 void bitmap_print_sb(struct bitmap *bitmap)
450 if (!bitmap || !bitmap->sb_page)
452 sb = kmap_atomic(bitmap->sb_page);
453 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
454 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
455 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
456 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
457 *(__u32 *)(sb->uuid+0),
458 *(__u32 *)(sb->uuid+4),
459 *(__u32 *)(sb->uuid+8),
460 *(__u32 *)(sb->uuid+12));
461 printk(KERN_DEBUG " events: %llu\n",
462 (unsigned long long) le64_to_cpu(sb->events));
463 printk(KERN_DEBUG "events cleared: %llu\n",
464 (unsigned long long) le64_to_cpu(sb->events_cleared));
465 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
466 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
467 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
468 printk(KERN_DEBUG " sync size: %llu KB\n",
469 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
470 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
478 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
479 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
480 * This function verifies 'bitmap_info' and populates the on-disk bitmap
481 * structure, which is to be written to disk.
483 * Returns: 0 on success, -Exxx on error
485 static int bitmap_new_disk_sb(struct bitmap *bitmap)
488 unsigned long chunksize, daemon_sleep, write_behind;
491 bitmap->sb_page = alloc_page(GFP_KERNEL);
492 if (IS_ERR(bitmap->sb_page)) {
493 err = PTR_ERR(bitmap->sb_page);
494 bitmap->sb_page = NULL;
497 bitmap->sb_page->index = 0;
499 sb = kmap_atomic(bitmap->sb_page);
501 sb->magic = cpu_to_le32(BITMAP_MAGIC);
502 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
504 chunksize = bitmap->mddev->bitmap_info.chunksize;
506 if (!is_power_of_2(chunksize)) {
508 printk(KERN_ERR "bitmap chunksize not a power of 2\n");
511 sb->chunksize = cpu_to_le32(chunksize);
513 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
515 (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
516 printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
517 daemon_sleep = 5 * HZ;
519 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
520 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
523 * FIXME: write_behind for RAID1. If not specified, what
524 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
526 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
527 if (write_behind > COUNTER_MAX)
528 write_behind = COUNTER_MAX / 2;
529 sb->write_behind = cpu_to_le32(write_behind);
530 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
532 /* keep the array size field of the bitmap superblock up to date */
533 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
535 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
537 bitmap->flags |= BITMAP_STALE;
538 sb->state |= cpu_to_le32(BITMAP_STALE);
539 bitmap->events_cleared = bitmap->mddev->events;
540 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
542 bitmap->flags |= BITMAP_HOSTENDIAN;
543 sb->version = cpu_to_le32(BITMAP_MAJOR_HOSTENDIAN);
550 /* read the superblock from the bitmap file and initialize some bitmap fields */
551 static int bitmap_read_sb(struct bitmap *bitmap)
555 unsigned long chunksize, daemon_sleep, write_behind;
556 unsigned long long events;
559 /* page 0 is the superblock, read it... */
561 loff_t isize = i_size_read(bitmap->file->f_mapping->host);
562 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
564 bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
566 bitmap->sb_page = read_sb_page(bitmap->mddev,
567 bitmap->mddev->bitmap_info.offset,
569 0, sizeof(bitmap_super_t));
571 if (IS_ERR(bitmap->sb_page)) {
572 err = PTR_ERR(bitmap->sb_page);
573 bitmap->sb_page = NULL;
577 sb = kmap_atomic(bitmap->sb_page);
579 chunksize = le32_to_cpu(sb->chunksize);
580 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
581 write_behind = le32_to_cpu(sb->write_behind);
583 /* verify that the bitmap-specific fields are valid */
584 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
585 reason = "bad magic";
586 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
587 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
588 reason = "unrecognized superblock version";
589 else if (chunksize < 512)
590 reason = "bitmap chunksize too small";
591 else if (!is_power_of_2(chunksize))
592 reason = "bitmap chunksize not a power of 2";
593 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
594 reason = "daemon sleep period out of range";
595 else if (write_behind > COUNTER_MAX)
596 reason = "write-behind limit out of range (0 - 16383)";
598 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
599 bmname(bitmap), reason);
603 /* keep the array size field of the bitmap superblock up to date */
604 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
606 if (bitmap->mddev->persistent) {
608 * We have a persistent array superblock, so compare the
609 * bitmap's UUID and event counter to the mddev's
611 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
613 "%s: bitmap superblock UUID mismatch\n",
617 events = le64_to_cpu(sb->events);
618 if (events < bitmap->mddev->events) {
620 "%s: bitmap file is out of date (%llu < %llu) "
621 "-- forcing full recovery\n",
622 bmname(bitmap), events,
623 (unsigned long long) bitmap->mddev->events);
624 sb->state |= cpu_to_le32(BITMAP_STALE);
628 /* assign fields using values from superblock */
629 bitmap->mddev->bitmap_info.chunksize = chunksize;
630 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
631 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
632 bitmap->flags |= le32_to_cpu(sb->state);
633 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
634 bitmap->flags |= BITMAP_HOSTENDIAN;
635 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
636 if (bitmap->flags & BITMAP_STALE)
637 bitmap->events_cleared = bitmap->mddev->events;
642 bitmap_print_sb(bitmap);
646 enum bitmap_mask_op {
651 /* record the state of the bitmap in the superblock. Return the old value */
652 static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
653 enum bitmap_mask_op op)
658 if (!bitmap->sb_page) /* can't set the state */
660 sb = kmap_atomic(bitmap->sb_page);
661 old = le32_to_cpu(sb->state) & bits;
664 sb->state |= cpu_to_le32(bits);
665 bitmap->flags |= bits;
668 sb->state &= cpu_to_le32(~bits);
669 bitmap->flags &= ~bits;
679 * general bitmap file operations
685 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
686 * file a page at a time. There's a superblock at the start of the file.
688 /* calculate the index of the page that contains this bit */
689 static inline unsigned long file_page_index(struct bitmap *bitmap, unsigned long chunk)
691 if (!bitmap->mddev->bitmap_info.external)
692 chunk += sizeof(bitmap_super_t) << 3;
693 return chunk >> PAGE_BIT_SHIFT;
696 /* calculate the (bit) offset of this bit within a page */
697 static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned long chunk)
699 if (!bitmap->mddev->bitmap_info.external)
700 chunk += sizeof(bitmap_super_t) << 3;
701 return chunk & (PAGE_BITS - 1);
705 * return a pointer to the page in the filemap that contains the given bit
707 * this lookup is complicated by the fact that the bitmap sb might be exactly
708 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
711 static inline struct page *filemap_get_page(struct bitmap *bitmap,
714 if (file_page_index(bitmap, chunk) >= bitmap->file_pages)
716 return bitmap->filemap[file_page_index(bitmap, chunk)
717 - file_page_index(bitmap, 0)];
720 static void bitmap_file_unmap(struct bitmap *bitmap)
722 struct page **map, *sb_page;
727 spin_lock_irqsave(&bitmap->lock, flags);
728 map = bitmap->filemap;
729 bitmap->filemap = NULL;
730 attr = bitmap->filemap_attr;
731 bitmap->filemap_attr = NULL;
732 pages = bitmap->file_pages;
733 bitmap->file_pages = 0;
734 sb_page = bitmap->sb_page;
735 bitmap->sb_page = NULL;
736 spin_unlock_irqrestore(&bitmap->lock, flags);
739 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
740 free_buffers(map[pages]);
745 free_buffers(sb_page);
748 static void bitmap_file_put(struct bitmap *bitmap)
753 spin_lock_irqsave(&bitmap->lock, flags);
756 spin_unlock_irqrestore(&bitmap->lock, flags);
759 wait_event(bitmap->write_wait,
760 atomic_read(&bitmap->pending_writes)==0);
761 bitmap_file_unmap(bitmap);
764 struct inode *inode = file->f_path.dentry->d_inode;
765 invalidate_mapping_pages(inode->i_mapping, 0, -1);
771 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
772 * then it is no longer reliable, so we stop using it and we mark the file
773 * as failed in the superblock
775 static void bitmap_file_kick(struct bitmap *bitmap)
777 char *path, *ptr = NULL;
779 if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
780 bitmap_update_sb(bitmap);
783 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
785 ptr = d_path(&bitmap->file->f_path, path,
789 "%s: kicking failed bitmap file %s from array!\n",
790 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
795 "%s: disabling internal bitmap due to errors\n",
799 bitmap_file_put(bitmap);
804 enum bitmap_page_attr {
805 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
806 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
807 * i.e. counter is 1 or 2. */
808 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
811 static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
812 enum bitmap_page_attr attr)
814 __set_bit((page->index<<2) + attr, bitmap->filemap_attr);
817 static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
818 enum bitmap_page_attr attr)
820 __clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
823 static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
824 enum bitmap_page_attr attr)
826 return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
830 * bitmap_file_set_bit -- called before performing a write to the md device
831 * to set (and eventually sync) a particular bit in the bitmap file
833 * we set the bit immediately, then we record the page number so that
834 * when an unplug occurs, we can flush the dirty pages out to disk
836 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
841 unsigned long chunk = block >> bitmap->chunkshift;
843 if (!bitmap->filemap)
846 page = filemap_get_page(bitmap, chunk);
849 bit = file_page_offset(bitmap, chunk);
852 kaddr = kmap_atomic(page);
853 if (bitmap->flags & BITMAP_HOSTENDIAN)
856 __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, BITMAP_PAGE_DIRTY);
863 /* this gets called when the md device is ready to unplug its underlying
864 * (slave) device queues -- before we let any writes go down, we need to
865 * sync the dirty pages of the bitmap file to disk */
866 void bitmap_unplug(struct bitmap *bitmap)
868 unsigned long i, flags;
869 int dirty, need_write;
876 /* look at each page to see if there are any set bits that need to be
877 * flushed out to disk */
878 for (i = 0; i < bitmap->file_pages; i++) {
879 spin_lock_irqsave(&bitmap->lock, flags);
880 if (!bitmap->filemap) {
881 spin_unlock_irqrestore(&bitmap->lock, flags);
884 page = bitmap->filemap[i];
885 dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
886 need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
887 clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
888 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
891 spin_unlock_irqrestore(&bitmap->lock, flags);
893 if (dirty || need_write)
894 write_page(bitmap, page, 0);
896 if (wait) { /* if any writes were performed, we need to wait on them */
898 wait_event(bitmap->write_wait,
899 atomic_read(&bitmap->pending_writes)==0);
901 md_super_wait(bitmap->mddev);
903 if (bitmap->flags & BITMAP_WRITE_ERROR)
904 bitmap_file_kick(bitmap);
906 EXPORT_SYMBOL(bitmap_unplug);
908 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
909 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
910 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
911 * memory mapping of the bitmap file
913 * if there's no bitmap file, or if the bitmap file had been
914 * previously kicked from the array, we mark all the bits as
915 * 1's in order to cause a full resync.
917 * We ignore all bits for sectors that end earlier than 'start'.
918 * This is used when reading an out-of-date bitmap...
920 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
922 unsigned long i, chunks, index, oldindex, bit;
923 struct page *page = NULL, *oldpage = NULL;
924 unsigned long num_pages, bit_cnt = 0;
926 unsigned long bytes, offset;
931 chunks = bitmap->chunks;
934 BUG_ON(!file && !bitmap->mddev->bitmap_info.offset);
936 outofdate = bitmap->flags & BITMAP_STALE;
938 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
939 "recovery\n", bmname(bitmap));
941 bytes = DIV_ROUND_UP(bitmap->chunks, 8);
942 if (!bitmap->mddev->bitmap_info.external)
943 bytes += sizeof(bitmap_super_t);
945 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
947 if (file && i_size_read(file->f_mapping->host) < bytes) {
948 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
950 (unsigned long) i_size_read(file->f_mapping->host),
957 bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
958 if (!bitmap->filemap)
961 /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
962 bitmap->filemap_attr = kzalloc(
963 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
965 if (!bitmap->filemap_attr)
970 for (i = 0; i < chunks; i++) {
972 index = file_page_index(bitmap, i);
973 bit = file_page_offset(bitmap, i);
974 if (index != oldindex) { /* this is a new page, read it in */
976 /* unmap the old page, we're done with it */
977 if (index == num_pages-1)
978 count = bytes - index * PAGE_SIZE;
981 if (index == 0 && bitmap->sb_page) {
983 * if we're here then the superblock page
984 * contains some bits (PAGE_SIZE != sizeof sb)
985 * we've already read it in, so just use it
987 page = bitmap->sb_page;
988 offset = sizeof(bitmap_super_t);
992 bitmap->mddev->bitmap_info.offset,
996 page = read_page(file, index, bitmap, count);
999 page = read_sb_page(bitmap->mddev,
1000 bitmap->mddev->bitmap_info.offset,
1005 if (IS_ERR(page)) { /* read error */
1006 ret = PTR_ERR(page);
1013 bitmap->filemap[bitmap->file_pages++] = page;
1014 bitmap->last_page_size = count;
1018 * if bitmap is out of date, dirty the
1019 * whole page and write it out
1021 paddr = kmap_atomic(page);
1022 memset(paddr + offset, 0xff,
1023 PAGE_SIZE - offset);
1024 kunmap_atomic(paddr);
1025 write_page(bitmap, page, 1);
1028 if (bitmap->flags & BITMAP_WRITE_ERROR)
1032 paddr = kmap_atomic(page);
1033 if (bitmap->flags & BITMAP_HOSTENDIAN)
1034 b = test_bit(bit, paddr);
1036 b = test_bit_le(bit, paddr);
1037 kunmap_atomic(paddr);
1039 /* if the disk bit is set, set the memory bit */
1040 int needed = ((sector_t)(i+1) << bitmap->chunkshift
1042 bitmap_set_memory_bits(bitmap,
1043 (sector_t)i << bitmap->chunkshift,
1049 /* everything went OK */
1051 bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
1053 if (bit_cnt) { /* Kick recovery if any bits were set */
1054 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1055 md_wakeup_thread(bitmap->mddev->thread);
1058 printk(KERN_INFO "%s: bitmap initialized from disk: "
1059 "read %lu/%lu pages, set %lu of %lu bits\n",
1060 bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, chunks);
1065 printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1066 bmname(bitmap), ret);
1070 void bitmap_write_all(struct bitmap *bitmap)
1072 /* We don't actually write all bitmap blocks here,
1073 * just flag them as needing to be written
1077 spin_lock_irq(&bitmap->lock);
1078 for (i = 0; i < bitmap->file_pages; i++)
1079 set_page_attr(bitmap, bitmap->filemap[i],
1080 BITMAP_PAGE_NEEDWRITE);
1081 bitmap->allclean = 0;
1082 spin_unlock_irq(&bitmap->lock);
1085 static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
1087 sector_t chunk = offset >> bitmap->chunkshift;
1088 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1089 bitmap->bp[page].count += inc;
1090 bitmap_checkfree(bitmap, page);
1092 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1093 sector_t offset, sector_t *blocks,
1097 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1101 void bitmap_daemon_work(struct mddev *mddev)
1103 struct bitmap *bitmap;
1105 unsigned long flags;
1106 struct page *page = NULL, *lastpage = NULL;
1110 /* Use a mutex to guard daemon_work against
1113 mutex_lock(&mddev->bitmap_info.mutex);
1114 bitmap = mddev->bitmap;
1115 if (bitmap == NULL) {
1116 mutex_unlock(&mddev->bitmap_info.mutex);
1119 if (time_before(jiffies, bitmap->daemon_lastrun
1120 + mddev->bitmap_info.daemon_sleep))
1123 bitmap->daemon_lastrun = jiffies;
1124 if (bitmap->allclean) {
1125 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1128 bitmap->allclean = 1;
1130 spin_lock_irqsave(&bitmap->lock, flags);
1131 for (j = 0; j < bitmap->chunks; j++) {
1132 bitmap_counter_t *bmc;
1133 if (!bitmap->filemap)
1134 /* error or shutdown */
1137 page = filemap_get_page(bitmap, j);
1139 if (page != lastpage) {
1140 /* skip this page unless it's marked as needing cleaning */
1141 if (!test_page_attr(bitmap, page, BITMAP_PAGE_PENDING)) {
1142 int need_write = test_page_attr(bitmap, page,
1143 BITMAP_PAGE_NEEDWRITE);
1145 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1147 spin_unlock_irqrestore(&bitmap->lock, flags);
1149 write_page(bitmap, page, 0);
1150 spin_lock_irqsave(&bitmap->lock, flags);
1151 j |= (PAGE_BITS - 1);
1155 /* grab the new page, sync and release the old */
1156 if (lastpage != NULL) {
1157 if (test_page_attr(bitmap, lastpage,
1158 BITMAP_PAGE_NEEDWRITE)) {
1159 clear_page_attr(bitmap, lastpage,
1160 BITMAP_PAGE_NEEDWRITE);
1161 spin_unlock_irqrestore(&bitmap->lock, flags);
1162 write_page(bitmap, lastpage, 0);
1164 set_page_attr(bitmap, lastpage,
1165 BITMAP_PAGE_NEEDWRITE);
1166 bitmap->allclean = 0;
1167 spin_unlock_irqrestore(&bitmap->lock, flags);
1170 spin_unlock_irqrestore(&bitmap->lock, flags);
1173 /* We are possibly going to clear some bits, so make
1174 * sure that events_cleared is up-to-date.
1176 if (bitmap->need_sync &&
1177 mddev->bitmap_info.external == 0) {
1179 bitmap->need_sync = 0;
1180 sb = kmap_atomic(bitmap->sb_page);
1181 sb->events_cleared =
1182 cpu_to_le64(bitmap->events_cleared);
1184 write_page(bitmap, bitmap->sb_page, 1);
1186 spin_lock_irqsave(&bitmap->lock, flags);
1187 if (!bitmap->need_sync)
1188 clear_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
1190 bitmap->allclean = 0;
1192 bmc = bitmap_get_counter(bitmap,
1193 (sector_t)j << bitmap->chunkshift,
1196 j |= PAGE_COUNTER_MASK;
1198 if (*bmc == 1 && !bitmap->need_sync) {
1199 /* we can clear the bit */
1201 bitmap_count_page(bitmap,
1202 (sector_t)j << bitmap->chunkshift,
1206 paddr = kmap_atomic(page);
1207 if (bitmap->flags & BITMAP_HOSTENDIAN)
1208 clear_bit(file_page_offset(bitmap, j),
1212 file_page_offset(bitmap,
1215 kunmap_atomic(paddr);
1216 } else if (*bmc <= 2) {
1217 *bmc = 1; /* maybe clear the bit next time */
1218 set_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
1219 bitmap->allclean = 0;
1223 spin_unlock_irqrestore(&bitmap->lock, flags);
1225 /* now sync the final page */
1226 if (lastpage != NULL) {
1227 spin_lock_irqsave(&bitmap->lock, flags);
1228 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1229 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1230 spin_unlock_irqrestore(&bitmap->lock, flags);
1231 write_page(bitmap, lastpage, 0);
1233 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1234 bitmap->allclean = 0;
1235 spin_unlock_irqrestore(&bitmap->lock, flags);
1240 if (bitmap->allclean == 0)
1241 mddev->thread->timeout =
1242 mddev->bitmap_info.daemon_sleep;
1243 mutex_unlock(&mddev->bitmap_info.mutex);
1246 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1247 sector_t offset, sector_t *blocks,
1249 __releases(bitmap->lock)
1250 __acquires(bitmap->lock)
1252 /* If 'create', we might release the lock and reclaim it.
1253 * The lock must have been taken with interrupts enabled.
1254 * If !create, we don't release the lock.
1256 sector_t chunk = offset >> bitmap->chunkshift;
1257 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1258 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1262 err = bitmap_checkpage(bitmap, page, create);
1264 if (bitmap->bp[page].hijacked ||
1265 bitmap->bp[page].map == NULL)
1266 csize = ((sector_t)1) << (bitmap->chunkshift +
1267 PAGE_COUNTER_SHIFT - 1);
1269 csize = ((sector_t)1) << bitmap->chunkshift;
1270 *blocks = csize - (offset & (csize - 1));
1275 /* now locked ... */
1277 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1278 /* should we use the first or second counter field
1279 * of the hijacked pointer? */
1280 int hi = (pageoff > PAGE_COUNTER_MASK);
1281 return &((bitmap_counter_t *)
1282 &bitmap->bp[page].map)[hi];
1283 } else /* page is allocated */
1284 return (bitmap_counter_t *)
1285 &(bitmap->bp[page].map[pageoff]);
1288 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1295 atomic_inc(&bitmap->behind_writes);
1296 bw = atomic_read(&bitmap->behind_writes);
1297 if (bw > bitmap->behind_writes_used)
1298 bitmap->behind_writes_used = bw;
1300 pr_debug("inc write-behind count %d/%lu\n",
1301 bw, bitmap->mddev->bitmap_info.max_write_behind);
1306 bitmap_counter_t *bmc;
1308 spin_lock_irq(&bitmap->lock);
1309 bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1311 spin_unlock_irq(&bitmap->lock);
1315 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1316 DEFINE_WAIT(__wait);
1317 /* note that it is safe to do the prepare_to_wait
1318 * after the test as long as we do it before dropping
1321 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1322 TASK_UNINTERRUPTIBLE);
1323 spin_unlock_irq(&bitmap->lock);
1325 finish_wait(&bitmap->overflow_wait, &__wait);
1331 bitmap_file_set_bit(bitmap, offset);
1332 bitmap_count_page(bitmap, offset, 1);
1340 spin_unlock_irq(&bitmap->lock);
1343 if (sectors > blocks)
1350 EXPORT_SYMBOL(bitmap_startwrite);
1352 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1353 int success, int behind)
1358 if (atomic_dec_and_test(&bitmap->behind_writes))
1359 wake_up(&bitmap->behind_wait);
1360 pr_debug("dec write-behind count %d/%lu\n",
1361 atomic_read(&bitmap->behind_writes),
1362 bitmap->mddev->bitmap_info.max_write_behind);
1367 unsigned long flags;
1368 bitmap_counter_t *bmc;
1370 spin_lock_irqsave(&bitmap->lock, flags);
1371 bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1373 spin_unlock_irqrestore(&bitmap->lock, flags);
1377 if (success && !bitmap->mddev->degraded &&
1378 bitmap->events_cleared < bitmap->mddev->events) {
1379 bitmap->events_cleared = bitmap->mddev->events;
1380 bitmap->need_sync = 1;
1381 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1384 if (!success && !NEEDED(*bmc))
1385 *bmc |= NEEDED_MASK;
1387 if (COUNTER(*bmc) == COUNTER_MAX)
1388 wake_up(&bitmap->overflow_wait);
1392 set_page_attr(bitmap,
1395 offset >> bitmap->chunkshift),
1396 BITMAP_PAGE_PENDING);
1397 bitmap->allclean = 0;
1399 spin_unlock_irqrestore(&bitmap->lock, flags);
1401 if (sectors > blocks)
1407 EXPORT_SYMBOL(bitmap_endwrite);
1409 static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1412 bitmap_counter_t *bmc;
1414 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1416 return 1; /* always resync if no bitmap */
1418 spin_lock_irq(&bitmap->lock);
1419 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1425 else if (NEEDED(*bmc)) {
1427 if (!degraded) { /* don't set/clear bits if degraded */
1428 *bmc |= RESYNC_MASK;
1429 *bmc &= ~NEEDED_MASK;
1433 spin_unlock_irq(&bitmap->lock);
1437 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1440 /* bitmap_start_sync must always report on multiples of whole
1441 * pages, otherwise resync (which is very PAGE_SIZE based) will
1443 * So call __bitmap_start_sync repeatedly (if needed) until
1444 * At least PAGE_SIZE>>9 blocks are covered.
1445 * Return the 'or' of the result.
1451 while (*blocks < (PAGE_SIZE>>9)) {
1452 rv |= __bitmap_start_sync(bitmap, offset,
1453 &blocks1, degraded);
1459 EXPORT_SYMBOL(bitmap_start_sync);
1461 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1463 bitmap_counter_t *bmc;
1464 unsigned long flags;
1466 if (bitmap == NULL) {
1470 spin_lock_irqsave(&bitmap->lock, flags);
1471 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1476 *bmc &= ~RESYNC_MASK;
1478 if (!NEEDED(*bmc) && aborted)
1479 *bmc |= NEEDED_MASK;
1482 set_page_attr(bitmap,
1483 filemap_get_page(bitmap, offset >> bitmap->chunkshift),
1484 BITMAP_PAGE_PENDING);
1485 bitmap->allclean = 0;
1490 spin_unlock_irqrestore(&bitmap->lock, flags);
1492 EXPORT_SYMBOL(bitmap_end_sync);
1494 void bitmap_close_sync(struct bitmap *bitmap)
1496 /* Sync has finished, and any bitmap chunks that weren't synced
1497 * properly have been aborted. It remains to us to clear the
1498 * RESYNC bit wherever it is still on
1500 sector_t sector = 0;
1504 while (sector < bitmap->mddev->resync_max_sectors) {
1505 bitmap_end_sync(bitmap, sector, &blocks, 0);
1509 EXPORT_SYMBOL(bitmap_close_sync);
1511 void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
1519 bitmap->last_end_sync = jiffies;
1522 if (time_before(jiffies, (bitmap->last_end_sync
1523 + bitmap->mddev->bitmap_info.daemon_sleep)))
1525 wait_event(bitmap->mddev->recovery_wait,
1526 atomic_read(&bitmap->mddev->recovery_active) == 0);
1528 bitmap->mddev->curr_resync_completed = sector;
1529 set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1530 sector &= ~((1ULL << bitmap->chunkshift) - 1);
1532 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1533 bitmap_end_sync(bitmap, s, &blocks, 0);
1536 bitmap->last_end_sync = jiffies;
1537 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1539 EXPORT_SYMBOL(bitmap_cond_end_sync);
1541 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1543 /* For each chunk covered by any of these sectors, set the
1544 * counter to 1 and set resync_needed. They should all
1545 * be 0 at this point
1549 bitmap_counter_t *bmc;
1550 spin_lock_irq(&bitmap->lock);
1551 bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1553 spin_unlock_irq(&bitmap->lock);
1558 *bmc = 2 | (needed ? NEEDED_MASK : 0);
1559 bitmap_count_page(bitmap, offset, 1);
1560 page = filemap_get_page(bitmap, offset >> bitmap->chunkshift);
1561 set_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
1562 bitmap->allclean = 0;
1564 spin_unlock_irq(&bitmap->lock);
1567 /* dirty the memory and file bits for bitmap chunks "s" to "e" */
1568 void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1570 unsigned long chunk;
1572 for (chunk = s; chunk <= e; chunk++) {
1573 sector_t sec = (sector_t)chunk << bitmap->chunkshift;
1574 bitmap_set_memory_bits(bitmap, sec, 1);
1575 spin_lock_irq(&bitmap->lock);
1576 bitmap_file_set_bit(bitmap, sec);
1577 spin_unlock_irq(&bitmap->lock);
1578 if (sec < bitmap->mddev->recovery_cp)
1579 /* We are asserting that the array is dirty,
1580 * so move the recovery_cp address back so
1581 * that it is obvious that it is dirty
1583 bitmap->mddev->recovery_cp = sec;
1588 * flush out any pending updates
1590 void bitmap_flush(struct mddev *mddev)
1592 struct bitmap *bitmap = mddev->bitmap;
1595 if (!bitmap) /* there was no bitmap */
1598 /* run the daemon_work three time to ensure everything is flushed
1601 sleep = mddev->bitmap_info.daemon_sleep * 2;
1602 bitmap->daemon_lastrun -= sleep;
1603 bitmap_daemon_work(mddev);
1604 bitmap->daemon_lastrun -= sleep;
1605 bitmap_daemon_work(mddev);
1606 bitmap->daemon_lastrun -= sleep;
1607 bitmap_daemon_work(mddev);
1608 bitmap_update_sb(bitmap);
1612 * free memory that was allocated
1614 static void bitmap_free(struct bitmap *bitmap)
1616 unsigned long k, pages;
1617 struct bitmap_page *bp;
1619 if (!bitmap) /* there was no bitmap */
1622 /* release the bitmap file and kill the daemon */
1623 bitmap_file_put(bitmap);
1626 pages = bitmap->pages;
1628 /* free all allocated memory */
1630 if (bp) /* deallocate the page memory */
1631 for (k = 0; k < pages; k++)
1632 if (bp[k].map && !bp[k].hijacked)
1638 void bitmap_destroy(struct mddev *mddev)
1640 struct bitmap *bitmap = mddev->bitmap;
1642 if (!bitmap) /* there was no bitmap */
1645 mutex_lock(&mddev->bitmap_info.mutex);
1646 mddev->bitmap = NULL; /* disconnect from the md device */
1647 mutex_unlock(&mddev->bitmap_info.mutex);
1649 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1651 if (bitmap->sysfs_can_clear)
1652 sysfs_put(bitmap->sysfs_can_clear);
1654 bitmap_free(bitmap);
1658 * initialize the bitmap structure
1659 * if this returns an error, bitmap_destroy must be called to do clean up
1661 int bitmap_create(struct mddev *mddev)
1663 struct bitmap *bitmap;
1664 sector_t blocks = mddev->resync_max_sectors;
1665 unsigned long chunks;
1666 unsigned long pages;
1667 struct file *file = mddev->bitmap_info.file;
1669 struct sysfs_dirent *bm = NULL;
1671 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1674 && !mddev->bitmap_info.offset) /* bitmap disabled, nothing to do */
1677 BUG_ON(file && mddev->bitmap_info.offset);
1679 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1683 spin_lock_init(&bitmap->lock);
1684 atomic_set(&bitmap->pending_writes, 0);
1685 init_waitqueue_head(&bitmap->write_wait);
1686 init_waitqueue_head(&bitmap->overflow_wait);
1687 init_waitqueue_head(&bitmap->behind_wait);
1689 bitmap->mddev = mddev;
1692 bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap");
1694 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear");
1697 bitmap->sysfs_can_clear = NULL;
1699 bitmap->file = file;
1702 /* As future accesses to this file will use bmap,
1703 * and bypass the page cache, we must sync the file
1708 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1709 if (!mddev->bitmap_info.external) {
1711 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1712 * instructing us to create a new on-disk bitmap instance.
1714 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1715 err = bitmap_new_disk_sb(bitmap);
1717 err = bitmap_read_sb(bitmap);
1720 if (mddev->bitmap_info.chunksize == 0 ||
1721 mddev->bitmap_info.daemon_sleep == 0)
1722 /* chunksize and time_base need to be
1729 bitmap->daemon_lastrun = jiffies;
1730 bitmap->chunkshift = (ffz(~mddev->bitmap_info.chunksize)
1731 - BITMAP_BLOCK_SHIFT);
1733 /* now that chunksize and chunkshift are set, we can use these macros */
1734 chunks = (blocks + bitmap->chunkshift - 1) >>
1736 pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1740 bitmap->chunks = chunks;
1741 bitmap->pages = pages;
1742 bitmap->missing_pages = pages;
1744 bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1750 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1751 pages, bmname(bitmap));
1753 mddev->bitmap = bitmap;
1756 return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
1759 bitmap_free(bitmap);
1763 int bitmap_load(struct mddev *mddev)
1767 sector_t sector = 0;
1768 struct bitmap *bitmap = mddev->bitmap;
1773 /* Clear out old bitmap info first: Either there is none, or we
1774 * are resuming after someone else has possibly changed things,
1775 * so we should forget old cached info.
1776 * All chunks should be clean, but some might need_sync.
1778 while (sector < mddev->resync_max_sectors) {
1780 bitmap_start_sync(bitmap, sector, &blocks, 0);
1783 bitmap_close_sync(bitmap);
1785 if (mddev->degraded == 0
1786 || bitmap->events_cleared == mddev->events)
1787 /* no need to keep dirty bits to optimise a
1788 * re-add of a missing device */
1789 start = mddev->recovery_cp;
1791 err = bitmap_init_from_disk(bitmap, start);
1796 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1797 md_wakeup_thread(mddev->thread);
1799 bitmap_update_sb(bitmap);
1801 if (bitmap->flags & BITMAP_WRITE_ERROR)
1806 EXPORT_SYMBOL_GPL(bitmap_load);
1808 void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
1810 unsigned long chunk_kb;
1811 unsigned long flags;
1816 spin_lock_irqsave(&bitmap->lock, flags);
1817 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
1818 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
1820 bitmap->pages - bitmap->missing_pages,
1822 (bitmap->pages - bitmap->missing_pages)
1823 << (PAGE_SHIFT - 10),
1824 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
1825 chunk_kb ? "KB" : "B");
1827 seq_printf(seq, ", file: ");
1828 seq_path(seq, &bitmap->file->f_path, " \t\n");
1831 seq_printf(seq, "\n");
1832 spin_unlock_irqrestore(&bitmap->lock, flags);
1836 location_show(struct mddev *mddev, char *page)
1839 if (mddev->bitmap_info.file)
1840 len = sprintf(page, "file");
1841 else if (mddev->bitmap_info.offset)
1842 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
1844 len = sprintf(page, "none");
1845 len += sprintf(page+len, "\n");
1850 location_store(struct mddev *mddev, const char *buf, size_t len)
1854 if (!mddev->pers->quiesce)
1856 if (mddev->recovery || mddev->sync_thread)
1860 if (mddev->bitmap || mddev->bitmap_info.file ||
1861 mddev->bitmap_info.offset) {
1862 /* bitmap already configured. Only option is to clear it */
1863 if (strncmp(buf, "none", 4) != 0)
1866 mddev->pers->quiesce(mddev, 1);
1867 bitmap_destroy(mddev);
1868 mddev->pers->quiesce(mddev, 0);
1870 mddev->bitmap_info.offset = 0;
1871 if (mddev->bitmap_info.file) {
1872 struct file *f = mddev->bitmap_info.file;
1873 mddev->bitmap_info.file = NULL;
1874 restore_bitmap_write_access(f);
1878 /* No bitmap, OK to set a location */
1880 if (strncmp(buf, "none", 4) == 0)
1881 /* nothing to be done */;
1882 else if (strncmp(buf, "file:", 5) == 0) {
1883 /* Not supported yet */
1888 rv = strict_strtoll(buf+1, 10, &offset);
1890 rv = strict_strtoll(buf, 10, &offset);
1895 if (mddev->bitmap_info.external == 0 &&
1896 mddev->major_version == 0 &&
1897 offset != mddev->bitmap_info.default_offset)
1899 mddev->bitmap_info.offset = offset;
1901 mddev->pers->quiesce(mddev, 1);
1902 rv = bitmap_create(mddev);
1904 rv = bitmap_load(mddev);
1906 bitmap_destroy(mddev);
1907 mddev->bitmap_info.offset = 0;
1909 mddev->pers->quiesce(mddev, 0);
1915 if (!mddev->external) {
1916 /* Ensure new bitmap info is stored in
1917 * metadata promptly.
1919 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1920 md_wakeup_thread(mddev->thread);
1925 static struct md_sysfs_entry bitmap_location =
1926 __ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
1929 timeout_show(struct mddev *mddev, char *page)
1932 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
1933 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
1935 len = sprintf(page, "%lu", secs);
1937 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
1938 len += sprintf(page+len, "\n");
1943 timeout_store(struct mddev *mddev, const char *buf, size_t len)
1945 /* timeout can be set at any time */
1946 unsigned long timeout;
1947 int rv = strict_strtoul_scaled(buf, &timeout, 4);
1951 /* just to make sure we don't overflow... */
1952 if (timeout >= LONG_MAX / HZ)
1955 timeout = timeout * HZ / 10000;
1957 if (timeout >= MAX_SCHEDULE_TIMEOUT)
1958 timeout = MAX_SCHEDULE_TIMEOUT-1;
1961 mddev->bitmap_info.daemon_sleep = timeout;
1962 if (mddev->thread) {
1963 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
1964 * the bitmap is all clean and we don't need to
1965 * adjust the timeout right now
1967 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
1968 mddev->thread->timeout = timeout;
1969 md_wakeup_thread(mddev->thread);
1975 static struct md_sysfs_entry bitmap_timeout =
1976 __ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
1979 backlog_show(struct mddev *mddev, char *page)
1981 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
1985 backlog_store(struct mddev *mddev, const char *buf, size_t len)
1987 unsigned long backlog;
1988 int rv = strict_strtoul(buf, 10, &backlog);
1991 if (backlog > COUNTER_MAX)
1993 mddev->bitmap_info.max_write_behind = backlog;
1997 static struct md_sysfs_entry bitmap_backlog =
1998 __ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2001 chunksize_show(struct mddev *mddev, char *page)
2003 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2007 chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2009 /* Can only be changed when no bitmap is active */
2011 unsigned long csize;
2014 rv = strict_strtoul(buf, 10, &csize);
2018 !is_power_of_2(csize))
2020 mddev->bitmap_info.chunksize = csize;
2024 static struct md_sysfs_entry bitmap_chunksize =
2025 __ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2027 static ssize_t metadata_show(struct mddev *mddev, char *page)
2029 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2030 ? "external" : "internal"));
2033 static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2035 if (mddev->bitmap ||
2036 mddev->bitmap_info.file ||
2037 mddev->bitmap_info.offset)
2039 if (strncmp(buf, "external", 8) == 0)
2040 mddev->bitmap_info.external = 1;
2041 else if (strncmp(buf, "internal", 8) == 0)
2042 mddev->bitmap_info.external = 0;
2048 static struct md_sysfs_entry bitmap_metadata =
2049 __ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2051 static ssize_t can_clear_show(struct mddev *mddev, char *page)
2055 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2058 len = sprintf(page, "\n");
2062 static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2064 if (mddev->bitmap == NULL)
2066 if (strncmp(buf, "false", 5) == 0)
2067 mddev->bitmap->need_sync = 1;
2068 else if (strncmp(buf, "true", 4) == 0) {
2069 if (mddev->degraded)
2071 mddev->bitmap->need_sync = 0;
2077 static struct md_sysfs_entry bitmap_can_clear =
2078 __ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2081 behind_writes_used_show(struct mddev *mddev, char *page)
2083 if (mddev->bitmap == NULL)
2084 return sprintf(page, "0\n");
2085 return sprintf(page, "%lu\n",
2086 mddev->bitmap->behind_writes_used);
2090 behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2093 mddev->bitmap->behind_writes_used = 0;
2097 static struct md_sysfs_entry max_backlog_used =
2098 __ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2099 behind_writes_used_show, behind_writes_used_reset);
2101 static struct attribute *md_bitmap_attrs[] = {
2102 &bitmap_location.attr,
2103 &bitmap_timeout.attr,
2104 &bitmap_backlog.attr,
2105 &bitmap_chunksize.attr,
2106 &bitmap_metadata.attr,
2107 &bitmap_can_clear.attr,
2108 &max_backlog_used.attr,
2111 struct attribute_group md_bitmap_group = {
2113 .attrs = md_bitmap_attrs,