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>
32 #include <linux/dm-dirty-log.h>
38 /* these are for debugging purposes only! */
40 /* define one and only one of these */
41 #define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
42 #define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
43 #define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
44 #define INJECT_FAULTS_4 0 /* undef */
45 #define INJECT_FAULTS_5 0 /* undef */
46 #define INJECT_FAULTS_6 0
48 /* if these are defined, the driver will fail! debug only */
49 #define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
50 #define INJECT_FATAL_FAULT_2 0 /* undef */
51 #define INJECT_FATAL_FAULT_3 0 /* undef */
56 # define PRINTK(x...) printk(KERN_DEBUG x)
62 static inline char *bmname(struct bitmap *bitmap)
64 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
68 * just a placeholder - calls kmalloc for bitmap pages
70 static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
74 #ifdef INJECT_FAULTS_1
77 page = kzalloc(PAGE_SIZE, GFP_NOIO);
80 printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
82 PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
83 bmname(bitmap), page);
88 * for now just a placeholder -- just calls kfree for bitmap pages
90 static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
92 PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
97 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
99 * 1) check to see if this page is allocated, if it's not then try to alloc
100 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
101 * page pointer directly as a counter
103 * if we find our page, we increment the page's refcount so that it stays
104 * allocated while we're using it
106 static int bitmap_checkpage(struct bitmap *bitmap,
107 unsigned long page, int create)
108 __releases(bitmap->lock)
109 __acquires(bitmap->lock)
111 unsigned char *mappage;
113 if (page >= bitmap->pages) {
114 /* This can happen if bitmap_start_sync goes beyond
115 * End-of-device while looking for a whole page.
121 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
124 if (bitmap->bp[page].map) /* page is already allocated, just return */
130 /* this page has not been allocated yet */
132 spin_unlock_irq(&bitmap->lock);
133 mappage = bitmap_alloc_page(bitmap);
134 spin_lock_irq(&bitmap->lock);
136 if (mappage == NULL) {
137 PRINTK("%s: bitmap map page allocation failed, hijacking\n",
139 /* failed - set the hijacked flag so that we can use the
140 * pointer as a counter */
141 if (!bitmap->bp[page].map)
142 bitmap->bp[page].hijacked = 1;
143 } else if (bitmap->bp[page].map ||
144 bitmap->bp[page].hijacked) {
145 /* somebody beat us to getting the page */
146 bitmap_free_page(bitmap, mappage);
150 /* no page was in place and we have one, so install it */
152 bitmap->bp[page].map = mappage;
153 bitmap->missing_pages--;
158 /* if page is completely empty, put it back on the free list, or dealloc it */
159 /* if page was hijacked, unmark the flag so it might get alloced next time */
160 /* Note: lock should be held when calling this */
161 static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
165 if (bitmap->bp[page].count) /* page is still busy */
168 /* page is no longer in use, it can be released */
170 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
171 bitmap->bp[page].hijacked = 0;
172 bitmap->bp[page].map = NULL;
174 /* normal case, free the page */
175 ptr = bitmap->bp[page].map;
176 bitmap->bp[page].map = NULL;
177 bitmap->missing_pages++;
178 bitmap_free_page(bitmap, ptr);
183 * bitmap file handling - read and write the bitmap file and its superblock
187 * basic page I/O operations
190 /* IO operations when bitmap is stored near all superblocks */
191 static struct page *read_sb_page(mddev_t *mddev, loff_t offset,
193 unsigned long index, int size)
195 /* choose a good rdev and read the page from there */
202 page = alloc_page(GFP_KERNEL);
204 return ERR_PTR(-ENOMEM);
208 list_for_each_entry(rdev, &mddev->disks, same_set) {
209 if (! test_bit(In_sync, &rdev->flags)
210 || test_bit(Faulty, &rdev->flags))
213 target = rdev->sb_start + offset + index * (PAGE_SIZE/512);
215 if (sync_page_io(rdev->bdev, target,
216 roundup(size, bdev_logical_block_size(rdev->bdev)),
219 attach_page_buffers(page, NULL); /* so that free_buffer will
226 return ERR_PTR(-EIO);
230 static mdk_rdev_t *next_active_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
232 /* Iterate the disks of an mddev, using rcu to protect access to the
233 * linked list, and raising the refcount of devices we return to ensure
234 * they don't disappear while in use.
235 * As devices are only added or removed when raid_disk is < 0 and
236 * nr_pending is 0 and In_sync is clear, the entries we return will
237 * still be in the same position on the list when we re-enter
238 * list_for_each_continue_rcu.
240 struct list_head *pos;
243 /* start at the beginning */
246 /* release the previous rdev and start from there. */
247 rdev_dec_pending(rdev, mddev);
248 pos = &rdev->same_set;
250 list_for_each_continue_rcu(pos, &mddev->disks) {
251 rdev = list_entry(pos, mdk_rdev_t, same_set);
252 if (rdev->raid_disk >= 0 &&
253 !test_bit(Faulty, &rdev->flags)) {
254 /* this is a usable devices */
255 atomic_inc(&rdev->nr_pending);
264 static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
266 mdk_rdev_t *rdev = NULL;
267 mddev_t *mddev = bitmap->mddev;
269 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
270 int size = PAGE_SIZE;
271 loff_t offset = mddev->bitmap_info.offset;
272 if (page->index == bitmap->file_pages-1)
273 size = roundup(bitmap->last_page_size,
274 bdev_logical_block_size(rdev->bdev));
275 /* Just make sure we aren't corrupting data or
278 if (mddev->external) {
279 /* Bitmap could be anywhere. */
280 if (rdev->sb_start + offset + (page->index
284 rdev->sb_start + offset
285 < (rdev->data_offset + mddev->dev_sectors
288 } else if (offset < 0) {
289 /* DATA BITMAP METADATA */
291 + (long)(page->index * (PAGE_SIZE/512))
293 /* bitmap runs in to metadata */
295 if (rdev->data_offset + mddev->dev_sectors
296 > rdev->sb_start + offset)
297 /* data runs in to bitmap */
299 } else if (rdev->sb_start < rdev->data_offset) {
300 /* METADATA BITMAP DATA */
303 + page->index*(PAGE_SIZE/512) + size/512
305 /* bitmap runs in to data */
308 /* DATA METADATA BITMAP - no problems */
310 md_super_write(mddev, rdev,
311 rdev->sb_start + offset
312 + page->index * (PAGE_SIZE/512),
318 md_super_wait(mddev);
325 static void bitmap_file_kick(struct bitmap *bitmap);
327 * write out a page to a file
329 static void write_page(struct bitmap *bitmap, struct page *page, int wait)
331 struct buffer_head *bh;
333 if (bitmap->file == NULL) {
334 switch (write_sb_page(bitmap, page, wait)) {
336 bitmap->flags |= BITMAP_WRITE_ERROR;
340 bh = page_buffers(page);
342 while (bh && bh->b_blocknr) {
343 atomic_inc(&bitmap->pending_writes);
344 set_buffer_locked(bh);
345 set_buffer_mapped(bh);
346 submit_bh(WRITE, bh);
347 bh = bh->b_this_page;
351 wait_event(bitmap->write_wait,
352 atomic_read(&bitmap->pending_writes)==0);
354 if (bitmap->flags & BITMAP_WRITE_ERROR)
355 bitmap_file_kick(bitmap);
358 static void end_bitmap_write(struct buffer_head *bh, int uptodate)
360 struct bitmap *bitmap = bh->b_private;
364 spin_lock_irqsave(&bitmap->lock, flags);
365 bitmap->flags |= BITMAP_WRITE_ERROR;
366 spin_unlock_irqrestore(&bitmap->lock, flags);
368 if (atomic_dec_and_test(&bitmap->pending_writes))
369 wake_up(&bitmap->write_wait);
372 /* copied from buffer.c */
374 __clear_page_buffers(struct page *page)
376 ClearPagePrivate(page);
377 set_page_private(page, 0);
378 page_cache_release(page);
380 static void free_buffers(struct page *page)
382 struct buffer_head *bh = page_buffers(page);
385 struct buffer_head *next = bh->b_this_page;
386 free_buffer_head(bh);
389 __clear_page_buffers(page);
393 /* read a page from a file.
394 * We both read the page, and attach buffers to the page to record the
395 * address of each block (using bmap). These addresses will be used
396 * to write the block later, completely bypassing the filesystem.
397 * This usage is similar to how swap files are handled, and allows us
398 * to write to a file with no concerns of memory allocation failing.
400 static struct page *read_page(struct file *file, unsigned long index,
401 struct bitmap *bitmap,
404 struct page *page = NULL;
405 struct inode *inode = file->f_path.dentry->d_inode;
406 struct buffer_head *bh;
409 PRINTK("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
410 (unsigned long long)index << PAGE_SHIFT);
412 page = alloc_page(GFP_KERNEL);
414 page = ERR_PTR(-ENOMEM);
418 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
421 page = ERR_PTR(-ENOMEM);
424 attach_page_buffers(page, bh);
425 block = index << (PAGE_SHIFT - inode->i_blkbits);
430 bh->b_blocknr = bmap(inode, block);
431 if (bh->b_blocknr == 0) {
432 /* Cannot use this file! */
434 page = ERR_PTR(-EINVAL);
437 bh->b_bdev = inode->i_sb->s_bdev;
438 if (count < (1<<inode->i_blkbits))
441 count -= (1<<inode->i_blkbits);
443 bh->b_end_io = end_bitmap_write;
444 bh->b_private = bitmap;
445 atomic_inc(&bitmap->pending_writes);
446 set_buffer_locked(bh);
447 set_buffer_mapped(bh);
451 bh = bh->b_this_page;
455 wait_event(bitmap->write_wait,
456 atomic_read(&bitmap->pending_writes)==0);
457 if (bitmap->flags & BITMAP_WRITE_ERROR) {
459 page = ERR_PTR(-EIO);
463 printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %ld\n",
465 (unsigned long long)index << PAGE_SHIFT,
471 * bitmap file superblock operations
474 /* update the event counter and sync the superblock to disk */
475 void bitmap_update_sb(struct bitmap *bitmap)
480 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
482 if (bitmap->mddev->bitmap_info.external)
484 spin_lock_irqsave(&bitmap->lock, flags);
485 if (!bitmap->sb_page) { /* no superblock */
486 spin_unlock_irqrestore(&bitmap->lock, flags);
489 spin_unlock_irqrestore(&bitmap->lock, flags);
490 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
491 sb->events = cpu_to_le64(bitmap->mddev->events);
492 if (bitmap->mddev->events < bitmap->events_cleared) {
493 /* rocking back to read-only */
494 bitmap->events_cleared = bitmap->mddev->events;
495 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
497 /* Just in case these have been changed via sysfs: */
498 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
499 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
500 kunmap_atomic(sb, KM_USER0);
501 write_page(bitmap, bitmap->sb_page, 1);
504 /* print out the bitmap file superblock */
505 void bitmap_print_sb(struct bitmap *bitmap)
509 if (!bitmap || !bitmap->sb_page)
511 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
512 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
513 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
514 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
515 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
516 *(__u32 *)(sb->uuid+0),
517 *(__u32 *)(sb->uuid+4),
518 *(__u32 *)(sb->uuid+8),
519 *(__u32 *)(sb->uuid+12));
520 printk(KERN_DEBUG " events: %llu\n",
521 (unsigned long long) le64_to_cpu(sb->events));
522 printk(KERN_DEBUG "events cleared: %llu\n",
523 (unsigned long long) le64_to_cpu(sb->events_cleared));
524 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
525 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
526 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
527 printk(KERN_DEBUG " sync size: %llu KB\n",
528 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
529 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
530 kunmap_atomic(sb, KM_USER0);
533 /* read the superblock from the bitmap file and initialize some bitmap fields */
534 static int bitmap_read_sb(struct bitmap *bitmap)
538 unsigned long chunksize, daemon_sleep, write_behind;
539 unsigned long long events;
542 /* page 0 is the superblock, read it... */
544 loff_t isize = i_size_read(bitmap->file->f_mapping->host);
545 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
547 bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
549 bitmap->sb_page = read_sb_page(bitmap->mddev,
550 bitmap->mddev->bitmap_info.offset,
552 0, sizeof(bitmap_super_t));
554 if (IS_ERR(bitmap->sb_page)) {
555 err = PTR_ERR(bitmap->sb_page);
556 bitmap->sb_page = NULL;
560 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
562 chunksize = le32_to_cpu(sb->chunksize);
563 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
564 write_behind = le32_to_cpu(sb->write_behind);
566 /* verify that the bitmap-specific fields are valid */
567 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
568 reason = "bad magic";
569 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
570 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
571 reason = "unrecognized superblock version";
572 else if (chunksize < 512)
573 reason = "bitmap chunksize too small";
574 else if ((1 << ffz(~chunksize)) != chunksize)
575 reason = "bitmap chunksize not a power of 2";
576 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
577 reason = "daemon sleep period out of range";
578 else if (write_behind > COUNTER_MAX)
579 reason = "write-behind limit out of range (0 - 16383)";
581 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
582 bmname(bitmap), reason);
586 /* keep the array size field of the bitmap superblock up to date */
587 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
589 if (!bitmap->mddev->persistent)
593 * if we have a persistent array superblock, compare the
594 * bitmap's UUID and event counter to the mddev's
596 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
597 printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
601 events = le64_to_cpu(sb->events);
602 if (events < bitmap->mddev->events) {
603 printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
604 "-- forcing full recovery\n", bmname(bitmap), events,
605 (unsigned long long) bitmap->mddev->events);
606 sb->state |= cpu_to_le32(BITMAP_STALE);
609 /* assign fields using values from superblock */
610 bitmap->mddev->bitmap_info.chunksize = chunksize;
611 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
612 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
613 bitmap->flags |= le32_to_cpu(sb->state);
614 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
615 bitmap->flags |= BITMAP_HOSTENDIAN;
616 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
617 if (sb->state & cpu_to_le32(BITMAP_STALE))
618 bitmap->events_cleared = bitmap->mddev->events;
621 kunmap_atomic(sb, KM_USER0);
623 bitmap_print_sb(bitmap);
627 enum bitmap_mask_op {
632 /* record the state of the bitmap in the superblock. Return the old value */
633 static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
634 enum bitmap_mask_op op)
640 spin_lock_irqsave(&bitmap->lock, flags);
641 if (!bitmap->sb_page) { /* can't set the state */
642 spin_unlock_irqrestore(&bitmap->lock, flags);
645 spin_unlock_irqrestore(&bitmap->lock, flags);
646 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
647 old = le32_to_cpu(sb->state) & bits;
650 sb->state |= cpu_to_le32(bits);
653 sb->state &= cpu_to_le32(~bits);
658 kunmap_atomic(sb, KM_USER0);
663 * general bitmap file operations
669 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
670 * file a page at a time. There's a superblock at the start of the file.
672 /* calculate the index of the page that contains this bit */
673 static inline unsigned long file_page_index(struct bitmap *bitmap, unsigned long chunk)
675 if (!bitmap->mddev->bitmap_info.external)
676 chunk += sizeof(bitmap_super_t) << 3;
677 return chunk >> PAGE_BIT_SHIFT;
680 /* calculate the (bit) offset of this bit within a page */
681 static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned long chunk)
683 if (!bitmap->mddev->bitmap_info.external)
684 chunk += sizeof(bitmap_super_t) << 3;
685 return chunk & (PAGE_BITS - 1);
689 * return a pointer to the page in the filemap that contains the given bit
691 * this lookup is complicated by the fact that the bitmap sb might be exactly
692 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
695 static inline struct page *filemap_get_page(struct bitmap *bitmap,
698 if (bitmap->filemap == NULL)
700 if (file_page_index(bitmap, chunk) >= bitmap->file_pages)
702 return bitmap->filemap[file_page_index(bitmap, chunk)
703 - file_page_index(bitmap, 0)];
706 static void bitmap_file_unmap(struct bitmap *bitmap)
708 struct page **map, *sb_page;
713 spin_lock_irqsave(&bitmap->lock, flags);
714 map = bitmap->filemap;
715 bitmap->filemap = NULL;
716 attr = bitmap->filemap_attr;
717 bitmap->filemap_attr = NULL;
718 pages = bitmap->file_pages;
719 bitmap->file_pages = 0;
720 sb_page = bitmap->sb_page;
721 bitmap->sb_page = NULL;
722 spin_unlock_irqrestore(&bitmap->lock, flags);
725 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
726 free_buffers(map[pages]);
731 free_buffers(sb_page);
734 static void bitmap_file_put(struct bitmap *bitmap)
739 spin_lock_irqsave(&bitmap->lock, flags);
742 spin_unlock_irqrestore(&bitmap->lock, flags);
745 wait_event(bitmap->write_wait,
746 atomic_read(&bitmap->pending_writes)==0);
747 bitmap_file_unmap(bitmap);
750 struct inode *inode = file->f_path.dentry->d_inode;
751 invalidate_mapping_pages(inode->i_mapping, 0, -1);
757 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
758 * then it is no longer reliable, so we stop using it and we mark the file
759 * as failed in the superblock
761 static void bitmap_file_kick(struct bitmap *bitmap)
763 char *path, *ptr = NULL;
765 if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
766 bitmap_update_sb(bitmap);
769 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
771 ptr = d_path(&bitmap->file->f_path, path,
775 "%s: kicking failed bitmap file %s from array!\n",
776 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
781 "%s: disabling internal bitmap due to errors\n",
785 bitmap_file_put(bitmap);
790 enum bitmap_page_attr {
791 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
792 BITMAP_PAGE_CLEAN = 1, /* there are bits that might need to be cleared */
793 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
796 static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
797 enum bitmap_page_attr attr)
800 __set_bit((page->index<<2) + attr, bitmap->filemap_attr);
802 __set_bit(attr, &bitmap->logattrs);
805 static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
806 enum bitmap_page_attr attr)
809 __clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
811 __clear_bit(attr, &bitmap->logattrs);
814 static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
815 enum bitmap_page_attr attr)
818 return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
820 return test_bit(attr, &bitmap->logattrs);
824 * bitmap_file_set_bit -- called before performing a write to the md device
825 * to set (and eventually sync) a particular bit in the bitmap file
827 * we set the bit immediately, then we record the page number so that
828 * when an unplug occurs, we can flush the dirty pages out to disk
830 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
833 struct page *page = NULL;
835 unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
837 if (!bitmap->filemap) {
838 struct dm_dirty_log *log = bitmap->mddev->bitmap_info.log;
840 log->type->mark_region(log, chunk);
843 page = filemap_get_page(bitmap, chunk);
846 bit = file_page_offset(bitmap, chunk);
849 kaddr = kmap_atomic(page, KM_USER0);
850 if (bitmap->flags & BITMAP_HOSTENDIAN)
853 ext2_set_bit(bit, kaddr);
854 kunmap_atomic(kaddr, KM_USER0);
855 PRINTK("set file bit %lu page %lu\n", bit, page->index);
857 /* record page number so it gets flushed to disk when unplug occurs */
858 set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
861 /* this gets called when the md device is ready to unplug its underlying
862 * (slave) device queues -- before we let any writes go down, we need to
863 * sync the dirty pages of the bitmap file to disk */
864 void bitmap_unplug(struct bitmap *bitmap)
866 unsigned long i, flags;
867 int dirty, need_write;
873 if (!bitmap->filemap) {
874 /* Must be using a dirty_log */
875 struct dm_dirty_log *log = bitmap->mddev->bitmap_info.log;
876 dirty = test_and_clear_bit(BITMAP_PAGE_DIRTY, &bitmap->logattrs);
877 need_write = test_and_clear_bit(BITMAP_PAGE_NEEDWRITE, &bitmap->logattrs);
878 if (dirty || need_write)
879 if (log->type->flush(log))
880 bitmap->flags |= BITMAP_WRITE_ERROR;
884 /* look at each page to see if there are any set bits that need to be
885 * flushed out to disk */
886 for (i = 0; i < bitmap->file_pages; i++) {
887 spin_lock_irqsave(&bitmap->lock, flags);
888 if (!bitmap->filemap) {
889 spin_unlock_irqrestore(&bitmap->lock, flags);
892 page = bitmap->filemap[i];
893 dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
894 need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
895 clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
896 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
899 spin_unlock_irqrestore(&bitmap->lock, flags);
901 if (dirty || need_write)
902 write_page(bitmap, page, 0);
904 if (wait) { /* if any writes were performed, we need to wait on them */
906 wait_event(bitmap->write_wait,
907 atomic_read(&bitmap->pending_writes)==0);
909 md_super_wait(bitmap->mddev);
912 if (bitmap->flags & BITMAP_WRITE_ERROR)
913 bitmap_file_kick(bitmap);
915 EXPORT_SYMBOL(bitmap_unplug);
917 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
918 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
919 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
920 * memory mapping of the bitmap file
922 * if there's no bitmap file, or if the bitmap file had been
923 * previously kicked from the array, we mark all the bits as
924 * 1's in order to cause a full resync.
926 * We ignore all bits for sectors that end earlier than 'start'.
927 * This is used when reading an out-of-date bitmap...
929 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
931 unsigned long i, chunks, index, oldindex, bit;
932 struct page *page = NULL, *oldpage = NULL;
933 unsigned long num_pages, bit_cnt = 0;
935 unsigned long bytes, offset;
940 chunks = bitmap->chunks;
943 BUG_ON(!file && !bitmap->mddev->bitmap_info.offset);
945 #ifdef INJECT_FAULTS_3
948 outofdate = bitmap->flags & BITMAP_STALE;
951 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
952 "recovery\n", bmname(bitmap));
954 bytes = DIV_ROUND_UP(bitmap->chunks, 8);
955 if (!bitmap->mddev->bitmap_info.external)
956 bytes += sizeof(bitmap_super_t);
958 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
960 if (file && i_size_read(file->f_mapping->host) < bytes) {
961 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
963 (unsigned long) i_size_read(file->f_mapping->host),
970 bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
971 if (!bitmap->filemap)
974 /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
975 bitmap->filemap_attr = kzalloc(
976 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
978 if (!bitmap->filemap_attr)
983 for (i = 0; i < chunks; i++) {
985 index = file_page_index(bitmap, i);
986 bit = file_page_offset(bitmap, i);
987 if (index != oldindex) { /* this is a new page, read it in */
989 /* unmap the old page, we're done with it */
990 if (index == num_pages-1)
991 count = bytes - index * PAGE_SIZE;
994 if (index == 0 && bitmap->sb_page) {
996 * if we're here then the superblock page
997 * contains some bits (PAGE_SIZE != sizeof sb)
998 * we've already read it in, so just use it
1000 page = bitmap->sb_page;
1001 offset = sizeof(bitmap_super_t);
1003 page = read_sb_page(
1005 bitmap->mddev->bitmap_info.offset,
1009 page = read_page(file, index, bitmap, count);
1012 page = read_sb_page(bitmap->mddev,
1013 bitmap->mddev->bitmap_info.offset,
1018 if (IS_ERR(page)) { /* read error */
1019 ret = PTR_ERR(page);
1026 bitmap->filemap[bitmap->file_pages++] = page;
1027 bitmap->last_page_size = count;
1031 * if bitmap is out of date, dirty the
1032 * whole page and write it out
1034 paddr = kmap_atomic(page, KM_USER0);
1035 memset(paddr + offset, 0xff,
1036 PAGE_SIZE - offset);
1037 kunmap_atomic(paddr, KM_USER0);
1038 write_page(bitmap, page, 1);
1041 if (bitmap->flags & BITMAP_WRITE_ERROR)
1045 paddr = kmap_atomic(page, KM_USER0);
1046 if (bitmap->flags & BITMAP_HOSTENDIAN)
1047 b = test_bit(bit, paddr);
1049 b = ext2_test_bit(bit, paddr);
1050 kunmap_atomic(paddr, KM_USER0);
1052 /* if the disk bit is set, set the memory bit */
1053 int needed = ((sector_t)(i+1) << (CHUNK_BLOCK_SHIFT(bitmap))
1055 bitmap_set_memory_bits(bitmap,
1056 (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap),
1059 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1063 /* everything went OK */
1065 bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
1067 if (bit_cnt) { /* Kick recovery if any bits were set */
1068 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1069 md_wakeup_thread(bitmap->mddev->thread);
1072 printk(KERN_INFO "%s: bitmap initialized from disk: "
1073 "read %lu/%lu pages, set %lu bits\n",
1074 bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt);
1079 printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1080 bmname(bitmap), ret);
1084 void bitmap_write_all(struct bitmap *bitmap)
1086 /* We don't actually write all bitmap blocks here,
1087 * just flag them as needing to be written
1091 for (i = 0; i < bitmap->file_pages; i++)
1092 set_page_attr(bitmap, bitmap->filemap[i],
1093 BITMAP_PAGE_NEEDWRITE);
1096 static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
1098 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1099 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1100 bitmap->bp[page].count += inc;
1101 bitmap_checkfree(bitmap, page);
1103 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1104 sector_t offset, int *blocks,
1108 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1112 void bitmap_daemon_work(mddev_t *mddev)
1114 struct bitmap *bitmap;
1116 unsigned long flags;
1117 struct page *page = NULL, *lastpage = NULL;
1120 struct dm_dirty_log *log = mddev->bitmap_info.log;
1122 /* Use a mutex to guard daemon_work against
1125 mutex_lock(&mddev->bitmap_info.mutex);
1126 bitmap = mddev->bitmap;
1127 if (bitmap == NULL) {
1128 mutex_unlock(&mddev->bitmap_info.mutex);
1131 if (time_before(jiffies, bitmap->daemon_lastrun
1132 + bitmap->mddev->bitmap_info.daemon_sleep))
1135 bitmap->daemon_lastrun = jiffies;
1136 if (bitmap->allclean) {
1137 bitmap->mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1140 bitmap->allclean = 1;
1142 spin_lock_irqsave(&bitmap->lock, flags);
1143 for (j = 0; j < bitmap->chunks; j++) {
1144 bitmap_counter_t *bmc;
1145 if (!bitmap->filemap) {
1147 /* error or shutdown */
1150 page = filemap_get_page(bitmap, j);
1152 if (page != lastpage) {
1153 /* skip this page unless it's marked as needing cleaning */
1154 if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
1155 int need_write = test_page_attr(bitmap, page,
1156 BITMAP_PAGE_NEEDWRITE);
1158 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1160 spin_unlock_irqrestore(&bitmap->lock, flags);
1162 write_page(bitmap, page, 0);
1163 bitmap->allclean = 0;
1165 spin_lock_irqsave(&bitmap->lock, flags);
1166 j |= (PAGE_BITS - 1);
1170 /* grab the new page, sync and release the old */
1171 if (lastpage != NULL) {
1172 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1173 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1174 spin_unlock_irqrestore(&bitmap->lock, flags);
1175 write_page(bitmap, lastpage, 0);
1177 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1178 spin_unlock_irqrestore(&bitmap->lock, flags);
1181 spin_unlock_irqrestore(&bitmap->lock, flags);
1184 /* We are possibly going to clear some bits, so make
1185 * sure that events_cleared is up-to-date.
1187 if (bitmap->need_sync &&
1188 bitmap->mddev->bitmap_info.external == 0) {
1190 bitmap->need_sync = 0;
1191 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
1192 sb->events_cleared =
1193 cpu_to_le64(bitmap->events_cleared);
1194 kunmap_atomic(sb, KM_USER0);
1195 write_page(bitmap, bitmap->sb_page, 1);
1197 spin_lock_irqsave(&bitmap->lock, flags);
1198 if (!bitmap->need_sync)
1199 clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1201 bmc = bitmap_get_counter(bitmap,
1202 (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
1206 bitmap->allclean = 0;
1209 *bmc = 1; /* maybe clear the bit next time */
1210 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1211 } else if (*bmc == 1 && !bitmap->need_sync) {
1212 /* we can clear the bit */
1214 bitmap_count_page(bitmap,
1215 (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
1220 paddr = kmap_atomic(page, KM_USER0);
1221 if (bitmap->flags & BITMAP_HOSTENDIAN)
1222 clear_bit(file_page_offset(bitmap, j),
1225 ext2_clear_bit(file_page_offset(bitmap, j),
1227 kunmap_atomic(paddr, KM_USER0);
1229 log->type->clear_region(log, j);
1232 j |= PAGE_COUNTER_MASK;
1234 spin_unlock_irqrestore(&bitmap->lock, flags);
1236 /* now sync the final page */
1237 if (lastpage != NULL || log != NULL) {
1238 spin_lock_irqsave(&bitmap->lock, flags);
1239 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1240 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1241 spin_unlock_irqrestore(&bitmap->lock, flags);
1243 write_page(bitmap, lastpage, 0);
1245 if (log->type->flush(log))
1246 bitmap->flags |= BITMAP_WRITE_ERROR;
1248 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1249 spin_unlock_irqrestore(&bitmap->lock, flags);
1254 if (bitmap->allclean == 0)
1255 bitmap->mddev->thread->timeout =
1256 bitmap->mddev->bitmap_info.daemon_sleep;
1257 mutex_unlock(&mddev->bitmap_info.mutex);
1260 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1261 sector_t offset, int *blocks,
1263 __releases(bitmap->lock)
1264 __acquires(bitmap->lock)
1266 /* If 'create', we might release the lock and reclaim it.
1267 * The lock must have been taken with interrupts enabled.
1268 * If !create, we don't release the lock.
1270 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1271 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1272 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1276 err = bitmap_checkpage(bitmap, page, create);
1278 if (bitmap->bp[page].hijacked ||
1279 bitmap->bp[page].map == NULL)
1280 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
1281 PAGE_COUNTER_SHIFT - 1);
1283 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1284 *blocks = csize - (offset & (csize - 1));
1289 /* now locked ... */
1291 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1292 /* should we use the first or second counter field
1293 * of the hijacked pointer? */
1294 int hi = (pageoff > PAGE_COUNTER_MASK);
1295 return &((bitmap_counter_t *)
1296 &bitmap->bp[page].map)[hi];
1297 } else /* page is allocated */
1298 return (bitmap_counter_t *)
1299 &(bitmap->bp[page].map[pageoff]);
1302 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1309 atomic_inc(&bitmap->behind_writes);
1310 bw = atomic_read(&bitmap->behind_writes);
1311 if (bw > bitmap->behind_writes_used)
1312 bitmap->behind_writes_used = bw;
1314 PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n",
1315 bw, bitmap->max_write_behind);
1320 bitmap_counter_t *bmc;
1322 spin_lock_irq(&bitmap->lock);
1323 bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1325 spin_unlock_irq(&bitmap->lock);
1329 if (unlikely((*bmc & COUNTER_MAX) == COUNTER_MAX)) {
1330 DEFINE_WAIT(__wait);
1331 /* note that it is safe to do the prepare_to_wait
1332 * after the test as long as we do it before dropping
1335 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1336 TASK_UNINTERRUPTIBLE);
1337 spin_unlock_irq(&bitmap->lock);
1338 md_unplug(bitmap->mddev);
1340 finish_wait(&bitmap->overflow_wait, &__wait);
1346 bitmap_file_set_bit(bitmap, offset);
1347 bitmap_count_page(bitmap, offset, 1);
1355 spin_unlock_irq(&bitmap->lock);
1358 if (sectors > blocks)
1363 bitmap->allclean = 0;
1366 EXPORT_SYMBOL(bitmap_startwrite);
1368 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1369 int success, int behind)
1374 if (atomic_dec_and_test(&bitmap->behind_writes))
1375 wake_up(&bitmap->behind_wait);
1376 PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n",
1377 atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1379 if (bitmap->mddev->degraded)
1380 /* Never clear bits or update events_cleared when degraded */
1385 unsigned long flags;
1386 bitmap_counter_t *bmc;
1388 spin_lock_irqsave(&bitmap->lock, flags);
1389 bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1391 spin_unlock_irqrestore(&bitmap->lock, flags);
1396 bitmap->events_cleared < bitmap->mddev->events) {
1397 bitmap->events_cleared = bitmap->mddev->events;
1398 bitmap->need_sync = 1;
1399 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1402 if (!success && ! (*bmc & NEEDED_MASK))
1403 *bmc |= NEEDED_MASK;
1405 if ((*bmc & COUNTER_MAX) == COUNTER_MAX)
1406 wake_up(&bitmap->overflow_wait);
1410 set_page_attr(bitmap,
1413 offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1416 spin_unlock_irqrestore(&bitmap->lock, flags);
1418 if (sectors > blocks)
1424 EXPORT_SYMBOL(bitmap_endwrite);
1426 static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
1429 bitmap_counter_t *bmc;
1431 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1433 return 1; /* always resync if no bitmap */
1435 spin_lock_irq(&bitmap->lock);
1436 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1442 else if (NEEDED(*bmc)) {
1444 if (!degraded) { /* don't set/clear bits if degraded */
1445 *bmc |= RESYNC_MASK;
1446 *bmc &= ~NEEDED_MASK;
1450 spin_unlock_irq(&bitmap->lock);
1451 bitmap->allclean = 0;
1455 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
1458 /* bitmap_start_sync must always report on multiples of whole
1459 * pages, otherwise resync (which is very PAGE_SIZE based) will
1461 * So call __bitmap_start_sync repeatedly (if needed) until
1462 * At least PAGE_SIZE>>9 blocks are covered.
1463 * Return the 'or' of the result.
1469 while (*blocks < (PAGE_SIZE>>9)) {
1470 rv |= __bitmap_start_sync(bitmap, offset,
1471 &blocks1, degraded);
1477 EXPORT_SYMBOL(bitmap_start_sync);
1479 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted)
1481 bitmap_counter_t *bmc;
1482 unsigned long flags;
1484 if (bitmap == NULL) {
1488 spin_lock_irqsave(&bitmap->lock, flags);
1489 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1494 *bmc &= ~RESYNC_MASK;
1496 if (!NEEDED(*bmc) && aborted)
1497 *bmc |= NEEDED_MASK;
1500 set_page_attr(bitmap,
1501 filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1506 spin_unlock_irqrestore(&bitmap->lock, flags);
1507 bitmap->allclean = 0;
1509 EXPORT_SYMBOL(bitmap_end_sync);
1511 void bitmap_close_sync(struct bitmap *bitmap)
1513 /* Sync has finished, and any bitmap chunks that weren't synced
1514 * properly have been aborted. It remains to us to clear the
1515 * RESYNC bit wherever it is still on
1517 sector_t sector = 0;
1521 while (sector < bitmap->mddev->resync_max_sectors) {
1522 bitmap_end_sync(bitmap, sector, &blocks, 0);
1526 EXPORT_SYMBOL(bitmap_close_sync);
1528 void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
1536 bitmap->last_end_sync = jiffies;
1539 if (time_before(jiffies, (bitmap->last_end_sync
1540 + bitmap->mddev->bitmap_info.daemon_sleep)))
1542 wait_event(bitmap->mddev->recovery_wait,
1543 atomic_read(&bitmap->mddev->recovery_active) == 0);
1545 bitmap->mddev->curr_resync_completed = bitmap->mddev->curr_resync;
1546 set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1547 sector &= ~((1ULL << CHUNK_BLOCK_SHIFT(bitmap)) - 1);
1549 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1550 bitmap_end_sync(bitmap, s, &blocks, 0);
1553 bitmap->last_end_sync = jiffies;
1554 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1556 EXPORT_SYMBOL(bitmap_cond_end_sync);
1558 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1560 /* For each chunk covered by any of these sectors, set the
1561 * counter to 1 and set resync_needed. They should all
1562 * be 0 at this point
1566 bitmap_counter_t *bmc;
1567 spin_lock_irq(&bitmap->lock);
1568 bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1570 spin_unlock_irq(&bitmap->lock);
1575 *bmc = 1 | (needed ? NEEDED_MASK : 0);
1576 bitmap_count_page(bitmap, offset, 1);
1577 page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
1578 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1580 spin_unlock_irq(&bitmap->lock);
1581 bitmap->allclean = 0;
1584 /* dirty the memory and file bits for bitmap chunks "s" to "e" */
1585 void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1587 unsigned long chunk;
1589 for (chunk = s; chunk <= e; chunk++) {
1590 sector_t sec = (sector_t)chunk << CHUNK_BLOCK_SHIFT(bitmap);
1591 bitmap_set_memory_bits(bitmap, sec, 1);
1592 bitmap_file_set_bit(bitmap, sec);
1593 if (sec < bitmap->mddev->recovery_cp)
1594 /* We are asserting that the array is dirty,
1595 * so move the recovery_cp address back so
1596 * that it is obvious that it is dirty
1598 bitmap->mddev->recovery_cp = sec;
1603 * flush out any pending updates
1605 void bitmap_flush(mddev_t *mddev)
1607 struct bitmap *bitmap = mddev->bitmap;
1610 if (!bitmap) /* there was no bitmap */
1613 /* run the daemon_work three time to ensure everything is flushed
1616 sleep = mddev->bitmap_info.daemon_sleep * 2;
1617 bitmap->daemon_lastrun -= sleep;
1618 bitmap_daemon_work(mddev);
1619 bitmap->daemon_lastrun -= sleep;
1620 bitmap_daemon_work(mddev);
1621 bitmap->daemon_lastrun -= sleep;
1622 bitmap_daemon_work(mddev);
1623 bitmap_update_sb(bitmap);
1627 * free memory that was allocated
1629 static void bitmap_free(struct bitmap *bitmap)
1631 unsigned long k, pages;
1632 struct bitmap_page *bp;
1634 if (!bitmap) /* there was no bitmap */
1637 /* release the bitmap file and kill the daemon */
1638 bitmap_file_put(bitmap);
1641 pages = bitmap->pages;
1643 /* free all allocated memory */
1645 if (bp) /* deallocate the page memory */
1646 for (k = 0; k < pages; k++)
1647 if (bp[k].map && !bp[k].hijacked)
1653 void bitmap_destroy(mddev_t *mddev)
1655 struct bitmap *bitmap = mddev->bitmap;
1657 if (!bitmap) /* there was no bitmap */
1660 mutex_lock(&mddev->bitmap_info.mutex);
1661 mddev->bitmap = NULL; /* disconnect from the md device */
1662 mutex_unlock(&mddev->bitmap_info.mutex);
1664 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1666 if (bitmap->sysfs_can_clear)
1667 sysfs_put(bitmap->sysfs_can_clear);
1669 bitmap_free(bitmap);
1673 * initialize the bitmap structure
1674 * if this returns an error, bitmap_destroy must be called to do clean up
1676 int bitmap_create(mddev_t *mddev)
1678 struct bitmap *bitmap;
1679 sector_t blocks = mddev->resync_max_sectors;
1680 unsigned long chunks;
1681 unsigned long pages;
1682 struct file *file = mddev->bitmap_info.file;
1684 struct sysfs_dirent *bm = NULL;
1686 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1689 && !mddev->bitmap_info.offset
1690 && !mddev->bitmap_info.log) /* bitmap disabled, nothing to do */
1693 BUG_ON(file && mddev->bitmap_info.offset);
1694 BUG_ON(mddev->bitmap_info.offset && mddev->bitmap_info.log);
1696 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1700 spin_lock_init(&bitmap->lock);
1701 atomic_set(&bitmap->pending_writes, 0);
1702 init_waitqueue_head(&bitmap->write_wait);
1703 init_waitqueue_head(&bitmap->overflow_wait);
1704 init_waitqueue_head(&bitmap->behind_wait);
1706 bitmap->mddev = mddev;
1709 bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap");
1711 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear");
1714 bitmap->sysfs_can_clear = NULL;
1716 bitmap->file = file;
1719 /* As future accesses to this file will use bmap,
1720 * and bypass the page cache, we must sync the file
1725 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1726 if (!mddev->bitmap_info.external)
1727 err = bitmap_read_sb(bitmap);
1730 if (mddev->bitmap_info.chunksize == 0 ||
1731 mddev->bitmap_info.daemon_sleep == 0)
1732 /* chunksize and time_base need to be
1739 bitmap->daemon_lastrun = jiffies;
1740 bitmap->chunkshift = ffz(~mddev->bitmap_info.chunksize);
1742 /* now that chunksize and chunkshift are set, we can use these macros */
1743 chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) >>
1744 CHUNK_BLOCK_SHIFT(bitmap);
1745 pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1749 bitmap->chunks = chunks;
1750 bitmap->pages = pages;
1751 bitmap->missing_pages = pages;
1752 bitmap->counter_bits = COUNTER_BITS;
1754 bitmap->syncchunk = ~0UL;
1756 #ifdef INJECT_FATAL_FAULT_1
1759 bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1765 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1766 pages, bmname(bitmap));
1768 mddev->bitmap = bitmap;
1771 return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
1774 bitmap_free(bitmap);
1778 int bitmap_load(mddev_t *mddev)
1781 sector_t sector = 0;
1782 struct bitmap *bitmap = mddev->bitmap;
1787 /* Clear out old bitmap info first: Either there is none, or we
1788 * are resuming after someone else has possibly changed things,
1789 * so we should forget old cached info.
1790 * All chunks should be clean, but some might need_sync.
1792 while (sector < mddev->resync_max_sectors) {
1794 bitmap_start_sync(bitmap, sector, &blocks, 0);
1797 bitmap_close_sync(bitmap);
1799 if (mddev->bitmap_info.log) {
1801 struct dm_dirty_log *log = mddev->bitmap_info.log;
1802 for (i = 0; i < bitmap->chunks; i++)
1803 if (!log->type->in_sync(log, i, 1))
1804 bitmap_set_memory_bits(bitmap,
1805 (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap),
1809 if (mddev->degraded == 0
1810 || bitmap->events_cleared == mddev->events)
1811 /* no need to keep dirty bits to optimise a
1812 * re-add of a missing device */
1813 start = mddev->recovery_cp;
1815 err = bitmap_init_from_disk(bitmap, start);
1820 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1821 md_wakeup_thread(mddev->thread);
1823 bitmap_update_sb(bitmap);
1825 if (bitmap->flags & BITMAP_WRITE_ERROR)
1830 EXPORT_SYMBOL_GPL(bitmap_load);
1833 location_show(mddev_t *mddev, char *page)
1836 if (mddev->bitmap_info.file)
1837 len = sprintf(page, "file");
1838 else if (mddev->bitmap_info.offset)
1839 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
1841 len = sprintf(page, "none");
1842 len += sprintf(page+len, "\n");
1847 location_store(mddev_t *mddev, const char *buf, size_t len)
1851 if (!mddev->pers->quiesce)
1853 if (mddev->recovery || mddev->sync_thread)
1857 if (mddev->bitmap || mddev->bitmap_info.file ||
1858 mddev->bitmap_info.offset) {
1859 /* bitmap already configured. Only option is to clear it */
1860 if (strncmp(buf, "none", 4) != 0)
1863 mddev->pers->quiesce(mddev, 1);
1864 bitmap_destroy(mddev);
1865 mddev->pers->quiesce(mddev, 0);
1867 mddev->bitmap_info.offset = 0;
1868 if (mddev->bitmap_info.file) {
1869 struct file *f = mddev->bitmap_info.file;
1870 mddev->bitmap_info.file = NULL;
1871 restore_bitmap_write_access(f);
1875 /* No bitmap, OK to set a location */
1877 if (strncmp(buf, "none", 4) == 0)
1878 /* nothing to be done */;
1879 else if (strncmp(buf, "file:", 5) == 0) {
1880 /* Not supported yet */
1885 rv = strict_strtoll(buf+1, 10, &offset);
1887 rv = strict_strtoll(buf, 10, &offset);
1892 if (mddev->bitmap_info.external == 0 &&
1893 mddev->major_version == 0 &&
1894 offset != mddev->bitmap_info.default_offset)
1896 mddev->bitmap_info.offset = offset;
1898 mddev->pers->quiesce(mddev, 1);
1899 rv = bitmap_create(mddev);
1901 bitmap_destroy(mddev);
1902 mddev->bitmap_info.offset = 0;
1904 mddev->pers->quiesce(mddev, 0);
1910 if (!mddev->external) {
1911 /* Ensure new bitmap info is stored in
1912 * metadata promptly.
1914 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1915 md_wakeup_thread(mddev->thread);
1920 static struct md_sysfs_entry bitmap_location =
1921 __ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
1924 timeout_show(mddev_t *mddev, char *page)
1927 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
1928 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
1930 len = sprintf(page, "%lu", secs);
1932 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
1933 len += sprintf(page+len, "\n");
1938 timeout_store(mddev_t *mddev, const char *buf, size_t len)
1940 /* timeout can be set at any time */
1941 unsigned long timeout;
1942 int rv = strict_strtoul_scaled(buf, &timeout, 4);
1946 /* just to make sure we don't overflow... */
1947 if (timeout >= LONG_MAX / HZ)
1950 timeout = timeout * HZ / 10000;
1952 if (timeout >= MAX_SCHEDULE_TIMEOUT)
1953 timeout = MAX_SCHEDULE_TIMEOUT-1;
1956 mddev->bitmap_info.daemon_sleep = timeout;
1957 if (mddev->thread) {
1958 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
1959 * the bitmap is all clean and we don't need to
1960 * adjust the timeout right now
1962 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
1963 mddev->thread->timeout = timeout;
1964 md_wakeup_thread(mddev->thread);
1970 static struct md_sysfs_entry bitmap_timeout =
1971 __ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
1974 backlog_show(mddev_t *mddev, char *page)
1976 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
1980 backlog_store(mddev_t *mddev, const char *buf, size_t len)
1982 unsigned long backlog;
1983 int rv = strict_strtoul(buf, 10, &backlog);
1986 if (backlog > COUNTER_MAX)
1988 mddev->bitmap_info.max_write_behind = backlog;
1992 static struct md_sysfs_entry bitmap_backlog =
1993 __ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
1996 chunksize_show(mddev_t *mddev, char *page)
1998 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2002 chunksize_store(mddev_t *mddev, const char *buf, size_t len)
2004 /* Can only be changed when no bitmap is active */
2006 unsigned long csize;
2009 rv = strict_strtoul(buf, 10, &csize);
2013 !is_power_of_2(csize))
2015 mddev->bitmap_info.chunksize = csize;
2019 static struct md_sysfs_entry bitmap_chunksize =
2020 __ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2022 static ssize_t metadata_show(mddev_t *mddev, char *page)
2024 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2025 ? "external" : "internal"));
2028 static ssize_t metadata_store(mddev_t *mddev, const char *buf, size_t len)
2030 if (mddev->bitmap ||
2031 mddev->bitmap_info.file ||
2032 mddev->bitmap_info.offset)
2034 if (strncmp(buf, "external", 8) == 0)
2035 mddev->bitmap_info.external = 1;
2036 else if (strncmp(buf, "internal", 8) == 0)
2037 mddev->bitmap_info.external = 0;
2043 static struct md_sysfs_entry bitmap_metadata =
2044 __ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2046 static ssize_t can_clear_show(mddev_t *mddev, char *page)
2050 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2053 len = sprintf(page, "\n");
2057 static ssize_t can_clear_store(mddev_t *mddev, const char *buf, size_t len)
2059 if (mddev->bitmap == NULL)
2061 if (strncmp(buf, "false", 5) == 0)
2062 mddev->bitmap->need_sync = 1;
2063 else if (strncmp(buf, "true", 4) == 0) {
2064 if (mddev->degraded)
2066 mddev->bitmap->need_sync = 0;
2072 static struct md_sysfs_entry bitmap_can_clear =
2073 __ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2076 behind_writes_used_show(mddev_t *mddev, char *page)
2078 if (mddev->bitmap == NULL)
2079 return sprintf(page, "0\n");
2080 return sprintf(page, "%lu\n",
2081 mddev->bitmap->behind_writes_used);
2085 behind_writes_used_reset(mddev_t *mddev, const char *buf, size_t len)
2088 mddev->bitmap->behind_writes_used = 0;
2092 static struct md_sysfs_entry max_backlog_used =
2093 __ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2094 behind_writes_used_show, behind_writes_used_reset);
2096 static struct attribute *md_bitmap_attrs[] = {
2097 &bitmap_location.attr,
2098 &bitmap_timeout.attr,
2099 &bitmap_backlog.attr,
2100 &bitmap_chunksize.attr,
2101 &bitmap_metadata.attr,
2102 &bitmap_can_clear.attr,
2103 &max_backlog_used.attr,
2106 struct attribute_group md_bitmap_group = {
2108 .attrs = md_bitmap_attrs,