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_counts *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("md/bitmap: map page allocation failed, hijacking\n");
80 /* failed - set the hijacked flag so that we can use the
81 * pointer as a counter */
82 if (!bitmap->bp[page].map)
83 bitmap->bp[page].hijacked = 1;
84 } else if (bitmap->bp[page].map ||
85 bitmap->bp[page].hijacked) {
86 /* somebody beat us to getting the page */
91 /* no page was in place and we have one, so install it */
93 bitmap->bp[page].map = mappage;
94 bitmap->missing_pages--;
99 /* if page is completely empty, put it back on the free list, or dealloc it */
100 /* if page was hijacked, unmark the flag so it might get alloced next time */
101 /* Note: lock should be held when calling this */
102 static void bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
106 if (bitmap->bp[page].count) /* page is still busy */
109 /* page is no longer in use, it can be released */
111 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
112 bitmap->bp[page].hijacked = 0;
113 bitmap->bp[page].map = NULL;
115 /* normal case, free the page */
116 ptr = bitmap->bp[page].map;
117 bitmap->bp[page].map = NULL;
118 bitmap->missing_pages++;
124 * bitmap file handling - read and write the bitmap file and its superblock
128 * basic page I/O operations
131 /* IO operations when bitmap is stored near all superblocks */
132 static int read_sb_page(struct mddev *mddev, loff_t offset,
134 unsigned long index, int size)
136 /* choose a good rdev and read the page from there */
138 struct md_rdev *rdev;
141 rdev_for_each(rdev, mddev) {
142 if (! test_bit(In_sync, &rdev->flags)
143 || test_bit(Faulty, &rdev->flags))
146 target = offset + index * (PAGE_SIZE/512);
148 if (sync_page_io(rdev, target,
149 roundup(size, bdev_logical_block_size(rdev->bdev)),
158 static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
160 /* Iterate the disks of an mddev, using rcu to protect access to the
161 * linked list, and raising the refcount of devices we return to ensure
162 * they don't disappear while in use.
163 * As devices are only added or removed when raid_disk is < 0 and
164 * nr_pending is 0 and In_sync is clear, the entries we return will
165 * still be in the same position on the list when we re-enter
166 * list_for_each_entry_continue_rcu.
170 /* start at the beginning */
171 rdev = list_entry_rcu(&mddev->disks, struct md_rdev, same_set);
173 /* release the previous rdev and start from there. */
174 rdev_dec_pending(rdev, mddev);
176 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
177 if (rdev->raid_disk >= 0 &&
178 !test_bit(Faulty, &rdev->flags)) {
179 /* this is a usable devices */
180 atomic_inc(&rdev->nr_pending);
189 static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
191 struct md_rdev *rdev = NULL;
192 struct block_device *bdev;
193 struct mddev *mddev = bitmap->mddev;
194 struct bitmap_storage *store = &bitmap->storage;
196 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
197 int size = PAGE_SIZE;
198 loff_t offset = mddev->bitmap_info.offset;
200 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
202 if (page->index == store->file_pages-1) {
203 int last_page_size = store->bytes & (PAGE_SIZE-1);
204 if (last_page_size == 0)
205 last_page_size = PAGE_SIZE;
206 size = roundup(last_page_size,
207 bdev_logical_block_size(bdev));
209 /* Just make sure we aren't corrupting data or
212 if (mddev->external) {
213 /* Bitmap could be anywhere. */
214 if (rdev->sb_start + offset + (page->index
218 rdev->sb_start + offset
219 < (rdev->data_offset + mddev->dev_sectors
222 } else if (offset < 0) {
223 /* DATA BITMAP METADATA */
225 + (long)(page->index * (PAGE_SIZE/512))
227 /* bitmap runs in to metadata */
229 if (rdev->data_offset + mddev->dev_sectors
230 > rdev->sb_start + offset)
231 /* data runs in to bitmap */
233 } else if (rdev->sb_start < rdev->data_offset) {
234 /* METADATA BITMAP DATA */
237 + page->index*(PAGE_SIZE/512) + size/512
239 /* bitmap runs in to data */
242 /* DATA METADATA BITMAP - no problems */
244 md_super_write(mddev, rdev,
245 rdev->sb_start + offset
246 + page->index * (PAGE_SIZE/512),
252 md_super_wait(mddev);
259 static void bitmap_file_kick(struct bitmap *bitmap);
261 * write out a page to a file
263 static void write_page(struct bitmap *bitmap, struct page *page, int wait)
265 struct buffer_head *bh;
267 if (bitmap->storage.file == NULL) {
268 switch (write_sb_page(bitmap, page, wait)) {
270 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
274 bh = page_buffers(page);
276 while (bh && bh->b_blocknr) {
277 atomic_inc(&bitmap->pending_writes);
278 set_buffer_locked(bh);
279 set_buffer_mapped(bh);
280 submit_bh(WRITE | REQ_SYNC, bh);
281 bh = bh->b_this_page;
285 wait_event(bitmap->write_wait,
286 atomic_read(&bitmap->pending_writes)==0);
288 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
289 bitmap_file_kick(bitmap);
292 static void end_bitmap_write(struct buffer_head *bh, int uptodate)
294 struct bitmap *bitmap = bh->b_private;
297 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
298 if (atomic_dec_and_test(&bitmap->pending_writes))
299 wake_up(&bitmap->write_wait);
302 /* copied from buffer.c */
304 __clear_page_buffers(struct page *page)
306 ClearPagePrivate(page);
307 set_page_private(page, 0);
308 page_cache_release(page);
310 static void free_buffers(struct page *page)
312 struct buffer_head *bh;
314 if (!PagePrivate(page))
317 bh = page_buffers(page);
319 struct buffer_head *next = bh->b_this_page;
320 free_buffer_head(bh);
323 __clear_page_buffers(page);
327 /* read a page from a file.
328 * We both read the page, and attach buffers to the page to record the
329 * address of each block (using bmap). These addresses will be used
330 * to write the block later, completely bypassing the filesystem.
331 * This usage is similar to how swap files are handled, and allows us
332 * to write to a file with no concerns of memory allocation failing.
334 static int read_page(struct file *file, unsigned long index,
335 struct bitmap *bitmap,
340 struct inode *inode = file_inode(file);
341 struct buffer_head *bh;
344 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
345 (unsigned long long)index << PAGE_SHIFT);
347 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
352 attach_page_buffers(page, bh);
353 block = index << (PAGE_SHIFT - inode->i_blkbits);
358 bh->b_blocknr = bmap(inode, block);
359 if (bh->b_blocknr == 0) {
360 /* Cannot use this file! */
364 bh->b_bdev = inode->i_sb->s_bdev;
365 if (count < (1<<inode->i_blkbits))
368 count -= (1<<inode->i_blkbits);
370 bh->b_end_io = end_bitmap_write;
371 bh->b_private = bitmap;
372 atomic_inc(&bitmap->pending_writes);
373 set_buffer_locked(bh);
374 set_buffer_mapped(bh);
378 bh = bh->b_this_page;
382 wait_event(bitmap->write_wait,
383 atomic_read(&bitmap->pending_writes)==0);
384 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
388 printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %d\n",
390 (unsigned long long)index << PAGE_SHIFT,
396 * bitmap file superblock operations
399 /* update the event counter and sync the superblock to disk */
400 void bitmap_update_sb(struct bitmap *bitmap)
404 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
406 if (bitmap->mddev->bitmap_info.external)
408 if (!bitmap->storage.sb_page) /* no superblock */
410 sb = kmap_atomic(bitmap->storage.sb_page);
411 sb->events = cpu_to_le64(bitmap->mddev->events);
412 if (bitmap->mddev->events < bitmap->events_cleared)
413 /* rocking back to read-only */
414 bitmap->events_cleared = bitmap->mddev->events;
415 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
416 sb->state = cpu_to_le32(bitmap->flags);
417 /* Just in case these have been changed via sysfs: */
418 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
419 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
420 /* This might have been changed by a reshape */
421 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
422 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
423 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
426 write_page(bitmap, bitmap->storage.sb_page, 1);
429 /* print out the bitmap file superblock */
430 void bitmap_print_sb(struct bitmap *bitmap)
434 if (!bitmap || !bitmap->storage.sb_page)
436 sb = kmap_atomic(bitmap->storage.sb_page);
437 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
438 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
439 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
440 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
441 *(__u32 *)(sb->uuid+0),
442 *(__u32 *)(sb->uuid+4),
443 *(__u32 *)(sb->uuid+8),
444 *(__u32 *)(sb->uuid+12));
445 printk(KERN_DEBUG " events: %llu\n",
446 (unsigned long long) le64_to_cpu(sb->events));
447 printk(KERN_DEBUG "events cleared: %llu\n",
448 (unsigned long long) le64_to_cpu(sb->events_cleared));
449 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
450 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
451 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
452 printk(KERN_DEBUG " sync size: %llu KB\n",
453 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
454 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
462 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
463 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
464 * This function verifies 'bitmap_info' and populates the on-disk bitmap
465 * structure, which is to be written to disk.
467 * Returns: 0 on success, -Exxx on error
469 static int bitmap_new_disk_sb(struct bitmap *bitmap)
472 unsigned long chunksize, daemon_sleep, write_behind;
474 bitmap->storage.sb_page = alloc_page(GFP_KERNEL);
475 if (bitmap->storage.sb_page == NULL)
477 bitmap->storage.sb_page->index = 0;
479 sb = kmap_atomic(bitmap->storage.sb_page);
481 sb->magic = cpu_to_le32(BITMAP_MAGIC);
482 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
484 chunksize = bitmap->mddev->bitmap_info.chunksize;
486 if (!is_power_of_2(chunksize)) {
488 printk(KERN_ERR "bitmap chunksize not a power of 2\n");
491 sb->chunksize = cpu_to_le32(chunksize);
493 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
495 (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
496 printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
497 daemon_sleep = 5 * HZ;
499 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
500 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
503 * FIXME: write_behind for RAID1. If not specified, what
504 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
506 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
507 if (write_behind > COUNTER_MAX)
508 write_behind = COUNTER_MAX / 2;
509 sb->write_behind = cpu_to_le32(write_behind);
510 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
512 /* keep the array size field of the bitmap superblock up to date */
513 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
515 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
517 set_bit(BITMAP_STALE, &bitmap->flags);
518 sb->state = cpu_to_le32(bitmap->flags);
519 bitmap->events_cleared = bitmap->mddev->events;
520 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
527 /* read the superblock from the bitmap file and initialize some bitmap fields */
528 static int bitmap_read_sb(struct bitmap *bitmap)
532 unsigned long chunksize, daemon_sleep, write_behind;
533 unsigned long long events;
534 unsigned long sectors_reserved = 0;
536 struct page *sb_page;
538 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
539 chunksize = 128 * 1024 * 1024;
540 daemon_sleep = 5 * HZ;
542 set_bit(BITMAP_STALE, &bitmap->flags);
546 /* page 0 is the superblock, read it... */
547 sb_page = alloc_page(GFP_KERNEL);
550 bitmap->storage.sb_page = sb_page;
552 if (bitmap->storage.file) {
553 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
554 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
556 err = read_page(bitmap->storage.file, 0,
557 bitmap, bytes, sb_page);
559 err = read_sb_page(bitmap->mddev,
560 bitmap->mddev->bitmap_info.offset,
562 0, sizeof(bitmap_super_t));
567 sb = kmap_atomic(sb_page);
569 chunksize = le32_to_cpu(sb->chunksize);
570 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
571 write_behind = le32_to_cpu(sb->write_behind);
572 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
574 /* verify that the bitmap-specific fields are valid */
575 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
576 reason = "bad magic";
577 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
578 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
579 reason = "unrecognized superblock version";
580 else if (chunksize < 512)
581 reason = "bitmap chunksize too small";
582 else if (!is_power_of_2(chunksize))
583 reason = "bitmap chunksize not a power of 2";
584 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
585 reason = "daemon sleep period out of range";
586 else if (write_behind > COUNTER_MAX)
587 reason = "write-behind limit out of range (0 - 16383)";
589 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
590 bmname(bitmap), reason);
594 /* keep the array size field of the bitmap superblock up to date */
595 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
597 if (bitmap->mddev->persistent) {
599 * We have a persistent array superblock, so compare the
600 * bitmap's UUID and event counter to the mddev's
602 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
604 "%s: bitmap superblock UUID mismatch\n",
608 events = le64_to_cpu(sb->events);
609 if (events < bitmap->mddev->events) {
611 "%s: bitmap file is out of date (%llu < %llu) "
612 "-- forcing full recovery\n",
613 bmname(bitmap), events,
614 (unsigned long long) bitmap->mddev->events);
615 set_bit(BITMAP_STALE, &bitmap->flags);
619 /* assign fields using values from superblock */
620 bitmap->flags |= le32_to_cpu(sb->state);
621 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
622 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
623 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
628 if (test_bit(BITMAP_STALE, &bitmap->flags))
629 bitmap->events_cleared = bitmap->mddev->events;
630 bitmap->mddev->bitmap_info.chunksize = chunksize;
631 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
632 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
633 if (bitmap->mddev->bitmap_info.space == 0 ||
634 bitmap->mddev->bitmap_info.space > sectors_reserved)
635 bitmap->mddev->bitmap_info.space = sectors_reserved;
637 bitmap_print_sb(bitmap);
642 * general bitmap file operations
648 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
649 * file a page at a time. There's a superblock at the start of the file.
651 /* calculate the index of the page that contains this bit */
652 static inline unsigned long file_page_index(struct bitmap_storage *store,
656 chunk += sizeof(bitmap_super_t) << 3;
657 return chunk >> PAGE_BIT_SHIFT;
660 /* calculate the (bit) offset of this bit within a page */
661 static inline unsigned long file_page_offset(struct bitmap_storage *store,
665 chunk += sizeof(bitmap_super_t) << 3;
666 return chunk & (PAGE_BITS - 1);
670 * return a pointer to the page in the filemap that contains the given bit
673 static inline struct page *filemap_get_page(struct bitmap_storage *store,
676 if (file_page_index(store, chunk) >= store->file_pages)
678 return store->filemap[file_page_index(store, chunk)];
681 static int bitmap_storage_alloc(struct bitmap_storage *store,
682 unsigned long chunks, int with_super)
685 unsigned long num_pages;
688 bytes = DIV_ROUND_UP(chunks, 8);
690 bytes += sizeof(bitmap_super_t);
692 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
694 store->filemap = kmalloc(sizeof(struct page *)
695 * num_pages, GFP_KERNEL);
699 if (with_super && !store->sb_page) {
700 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
701 if (store->sb_page == NULL)
703 store->sb_page->index = 0;
706 if (store->sb_page) {
707 store->filemap[0] = store->sb_page;
710 for ( ; pnum < num_pages; pnum++) {
711 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
712 if (!store->filemap[pnum]) {
713 store->file_pages = pnum;
716 store->filemap[pnum]->index = pnum;
718 store->file_pages = pnum;
720 /* We need 4 bits per page, rounded up to a multiple
721 * of sizeof(unsigned long) */
722 store->filemap_attr = kzalloc(
723 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
725 if (!store->filemap_attr)
728 store->bytes = bytes;
733 static void bitmap_file_unmap(struct bitmap_storage *store)
735 struct page **map, *sb_page;
740 map = store->filemap;
741 pages = store->file_pages;
742 sb_page = store->sb_page;
745 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
746 free_buffers(map[pages]);
748 kfree(store->filemap_attr);
751 free_buffers(sb_page);
754 struct inode *inode = file_inode(file);
755 invalidate_mapping_pages(inode->i_mapping, 0, -1);
761 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
762 * then it is no longer reliable, so we stop using it and we mark the file
763 * as failed in the superblock
765 static void bitmap_file_kick(struct bitmap *bitmap)
767 char *path, *ptr = NULL;
769 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
770 bitmap_update_sb(bitmap);
772 if (bitmap->storage.file) {
773 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
775 ptr = d_path(&bitmap->storage.file->f_path,
779 "%s: kicking failed bitmap file %s from array!\n",
780 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
785 "%s: disabling internal bitmap due to errors\n",
790 enum bitmap_page_attr {
791 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
792 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
793 * i.e. counter is 1 or 2. */
794 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
797 static inline void set_page_attr(struct bitmap *bitmap, int pnum,
798 enum bitmap_page_attr attr)
800 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
803 static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
804 enum bitmap_page_attr attr)
806 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
809 static inline int test_page_attr(struct bitmap *bitmap, int pnum,
810 enum bitmap_page_attr attr)
812 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
815 static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
816 enum bitmap_page_attr attr)
818 return test_and_clear_bit((pnum<<2) + attr,
819 bitmap->storage.filemap_attr);
822 * bitmap_file_set_bit -- called before performing a write to the md device
823 * to set (and eventually sync) a particular bit in the bitmap file
825 * we set the bit immediately, then we record the page number so that
826 * when an unplug occurs, we can flush the dirty pages out to disk
828 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
833 unsigned long chunk = block >> bitmap->counts.chunkshift;
835 page = filemap_get_page(&bitmap->storage, chunk);
838 bit = file_page_offset(&bitmap->storage, chunk);
841 kaddr = kmap_atomic(page);
842 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
845 set_bit_le(bit, kaddr);
846 kunmap_atomic(kaddr);
847 pr_debug("set file bit %lu page %lu\n", bit, page->index);
848 /* record page number so it gets flushed to disk when unplug occurs */
849 set_page_attr(bitmap, page->index, BITMAP_PAGE_DIRTY);
852 static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
857 unsigned long chunk = block >> bitmap->counts.chunkshift;
859 page = filemap_get_page(&bitmap->storage, chunk);
862 bit = file_page_offset(&bitmap->storage, chunk);
863 paddr = kmap_atomic(page);
864 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
865 clear_bit(bit, paddr);
867 clear_bit_le(bit, paddr);
868 kunmap_atomic(paddr);
869 if (!test_page_attr(bitmap, page->index, BITMAP_PAGE_NEEDWRITE)) {
870 set_page_attr(bitmap, page->index, BITMAP_PAGE_PENDING);
871 bitmap->allclean = 0;
875 /* this gets called when the md device is ready to unplug its underlying
876 * (slave) device queues -- before we let any writes go down, we need to
877 * sync the dirty pages of the bitmap file to disk */
878 void bitmap_unplug(struct bitmap *bitmap)
881 int dirty, need_write;
883 if (!bitmap || !bitmap->storage.filemap ||
884 test_bit(BITMAP_STALE, &bitmap->flags))
887 /* look at each page to see if there are any set bits that need to be
888 * flushed out to disk */
889 for (i = 0; i < bitmap->storage.file_pages; i++) {
890 if (!bitmap->storage.filemap)
892 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
893 need_write = test_and_clear_page_attr(bitmap, i,
894 BITMAP_PAGE_NEEDWRITE);
895 if (dirty || need_write) {
896 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
897 write_page(bitmap, bitmap->storage.filemap[i], 0);
900 if (bitmap->storage.file)
901 wait_event(bitmap->write_wait,
902 atomic_read(&bitmap->pending_writes)==0);
904 md_super_wait(bitmap->mddev);
906 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
907 bitmap_file_kick(bitmap);
909 EXPORT_SYMBOL(bitmap_unplug);
911 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
912 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
913 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
914 * memory mapping of the bitmap file
916 * if there's no bitmap file, or if the bitmap file had been
917 * previously kicked from the array, we mark all the bits as
918 * 1's in order to cause a full resync.
920 * We ignore all bits for sectors that end earlier than 'start'.
921 * This is used when reading an out-of-date bitmap...
923 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
925 unsigned long i, chunks, index, oldindex, bit;
926 struct page *page = NULL;
927 unsigned long bit_cnt = 0;
929 unsigned long offset;
933 struct bitmap_storage *store = &bitmap->storage;
935 chunks = bitmap->counts.chunks;
938 if (!file && !bitmap->mddev->bitmap_info.offset) {
939 /* No permanent bitmap - fill with '1s'. */
940 store->filemap = NULL;
941 store->file_pages = 0;
942 for (i = 0; i < chunks ; i++) {
943 /* if the disk bit is set, set the memory bit */
944 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
946 bitmap_set_memory_bits(bitmap,
947 (sector_t)i << bitmap->counts.chunkshift,
953 outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
955 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
956 "recovery\n", bmname(bitmap));
958 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
959 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
961 (unsigned long) i_size_read(file->f_mapping->host),
968 if (!bitmap->mddev->bitmap_info.external)
969 offset = sizeof(bitmap_super_t);
971 for (i = 0; i < chunks; i++) {
973 index = file_page_index(&bitmap->storage, i);
974 bit = file_page_offset(&bitmap->storage, i);
975 if (index != oldindex) { /* this is a new page, read it in */
977 /* unmap the old page, we're done with it */
978 if (index == store->file_pages-1)
979 count = store->bytes - index * PAGE_SIZE;
982 page = store->filemap[index];
984 ret = read_page(file, index, bitmap,
989 bitmap->mddev->bitmap_info.offset,
1000 * if bitmap is out of date, dirty the
1001 * whole page and write it out
1003 paddr = kmap_atomic(page);
1004 memset(paddr + offset, 0xff,
1005 PAGE_SIZE - offset);
1006 kunmap_atomic(paddr);
1007 write_page(bitmap, page, 1);
1010 if (test_bit(BITMAP_WRITE_ERROR,
1015 paddr = kmap_atomic(page);
1016 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1017 b = test_bit(bit, paddr);
1019 b = test_bit_le(bit, paddr);
1020 kunmap_atomic(paddr);
1022 /* if the disk bit is set, set the memory bit */
1023 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1025 bitmap_set_memory_bits(bitmap,
1026 (sector_t)i << bitmap->counts.chunkshift,
1033 printk(KERN_INFO "%s: bitmap initialized from disk: "
1034 "read %lu pages, set %lu of %lu bits\n",
1035 bmname(bitmap), store->file_pages,
1041 printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1042 bmname(bitmap), ret);
1046 void bitmap_write_all(struct bitmap *bitmap)
1048 /* We don't actually write all bitmap blocks here,
1049 * just flag them as needing to be written
1053 if (!bitmap || !bitmap->storage.filemap)
1055 if (bitmap->storage.file)
1056 /* Only one copy, so nothing needed */
1059 for (i = 0; i < bitmap->storage.file_pages; i++)
1060 set_page_attr(bitmap, i,
1061 BITMAP_PAGE_NEEDWRITE);
1062 bitmap->allclean = 0;
1065 static void bitmap_count_page(struct bitmap_counts *bitmap,
1066 sector_t offset, int inc)
1068 sector_t chunk = offset >> bitmap->chunkshift;
1069 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1070 bitmap->bp[page].count += inc;
1071 bitmap_checkfree(bitmap, page);
1074 static void bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1076 sector_t chunk = offset >> bitmap->chunkshift;
1077 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1078 struct bitmap_page *bp = &bitmap->bp[page];
1084 static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
1085 sector_t offset, sector_t *blocks,
1089 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1093 void bitmap_daemon_work(struct mddev *mddev)
1095 struct bitmap *bitmap;
1097 unsigned long nextpage;
1099 struct bitmap_counts *counts;
1101 /* Use a mutex to guard daemon_work against
1104 mutex_lock(&mddev->bitmap_info.mutex);
1105 bitmap = mddev->bitmap;
1106 if (bitmap == NULL) {
1107 mutex_unlock(&mddev->bitmap_info.mutex);
1110 if (time_before(jiffies, bitmap->daemon_lastrun
1111 + mddev->bitmap_info.daemon_sleep))
1114 bitmap->daemon_lastrun = jiffies;
1115 if (bitmap->allclean) {
1116 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1119 bitmap->allclean = 1;
1121 /* Any file-page which is PENDING now needs to be written.
1122 * So set NEEDWRITE now, then after we make any last-minute changes
1125 for (j = 0; j < bitmap->storage.file_pages; j++)
1126 if (test_and_clear_page_attr(bitmap, j,
1127 BITMAP_PAGE_PENDING))
1128 set_page_attr(bitmap, j,
1129 BITMAP_PAGE_NEEDWRITE);
1131 if (bitmap->need_sync &&
1132 mddev->bitmap_info.external == 0) {
1133 /* Arrange for superblock update as well as
1136 bitmap->need_sync = 0;
1137 if (bitmap->storage.filemap) {
1138 sb = kmap_atomic(bitmap->storage.sb_page);
1139 sb->events_cleared =
1140 cpu_to_le64(bitmap->events_cleared);
1142 set_page_attr(bitmap, 0,
1143 BITMAP_PAGE_NEEDWRITE);
1146 /* Now look at the bitmap counters and if any are '2' or '1',
1147 * decrement and handle accordingly.
1149 counts = &bitmap->counts;
1150 spin_lock_irq(&counts->lock);
1152 for (j = 0; j < counts->chunks; j++) {
1153 bitmap_counter_t *bmc;
1154 sector_t block = (sector_t)j << counts->chunkshift;
1156 if (j == nextpage) {
1157 nextpage += PAGE_COUNTER_RATIO;
1158 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1159 j |= PAGE_COUNTER_MASK;
1162 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1164 bmc = bitmap_get_counter(counts,
1169 j |= PAGE_COUNTER_MASK;
1172 if (*bmc == 1 && !bitmap->need_sync) {
1173 /* We can clear the bit */
1175 bitmap_count_page(counts, block, -1);
1176 bitmap_file_clear_bit(bitmap, block);
1177 } else if (*bmc && *bmc <= 2) {
1179 bitmap_set_pending(counts, block);
1180 bitmap->allclean = 0;
1183 spin_unlock_irq(&counts->lock);
1185 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1186 * DIRTY pages need to be written by bitmap_unplug so it can wait
1188 * If we find any DIRTY page we stop there and let bitmap_unplug
1189 * handle all the rest. This is important in the case where
1190 * the first blocking holds the superblock and it has been updated.
1191 * We mustn't write any other blocks before the superblock.
1194 j < bitmap->storage.file_pages
1195 && !test_bit(BITMAP_STALE, &bitmap->flags);
1198 if (test_page_attr(bitmap, j,
1200 /* bitmap_unplug will handle the rest */
1202 if (test_and_clear_page_attr(bitmap, j,
1203 BITMAP_PAGE_NEEDWRITE)) {
1204 write_page(bitmap, bitmap->storage.filemap[j], 0);
1209 if (bitmap->allclean == 0)
1210 mddev->thread->timeout =
1211 mddev->bitmap_info.daemon_sleep;
1212 mutex_unlock(&mddev->bitmap_info.mutex);
1215 static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
1216 sector_t offset, sector_t *blocks,
1218 __releases(bitmap->lock)
1219 __acquires(bitmap->lock)
1221 /* If 'create', we might release the lock and reclaim it.
1222 * The lock must have been taken with interrupts enabled.
1223 * If !create, we don't release the lock.
1225 sector_t chunk = offset >> bitmap->chunkshift;
1226 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1227 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1231 err = bitmap_checkpage(bitmap, page, create);
1233 if (bitmap->bp[page].hijacked ||
1234 bitmap->bp[page].map == NULL)
1235 csize = ((sector_t)1) << (bitmap->chunkshift +
1236 PAGE_COUNTER_SHIFT - 1);
1238 csize = ((sector_t)1) << bitmap->chunkshift;
1239 *blocks = csize - (offset & (csize - 1));
1244 /* now locked ... */
1246 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1247 /* should we use the first or second counter field
1248 * of the hijacked pointer? */
1249 int hi = (pageoff > PAGE_COUNTER_MASK);
1250 return &((bitmap_counter_t *)
1251 &bitmap->bp[page].map)[hi];
1252 } else /* page is allocated */
1253 return (bitmap_counter_t *)
1254 &(bitmap->bp[page].map[pageoff]);
1257 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1264 atomic_inc(&bitmap->behind_writes);
1265 bw = atomic_read(&bitmap->behind_writes);
1266 if (bw > bitmap->behind_writes_used)
1267 bitmap->behind_writes_used = bw;
1269 pr_debug("inc write-behind count %d/%lu\n",
1270 bw, bitmap->mddev->bitmap_info.max_write_behind);
1275 bitmap_counter_t *bmc;
1277 spin_lock_irq(&bitmap->counts.lock);
1278 bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1280 spin_unlock_irq(&bitmap->counts.lock);
1284 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1285 DEFINE_WAIT(__wait);
1286 /* note that it is safe to do the prepare_to_wait
1287 * after the test as long as we do it before dropping
1290 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1291 TASK_UNINTERRUPTIBLE);
1292 spin_unlock_irq(&bitmap->counts.lock);
1294 finish_wait(&bitmap->overflow_wait, &__wait);
1300 bitmap_file_set_bit(bitmap, offset);
1301 bitmap_count_page(&bitmap->counts, offset, 1);
1309 spin_unlock_irq(&bitmap->counts.lock);
1312 if (sectors > blocks)
1319 EXPORT_SYMBOL(bitmap_startwrite);
1321 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1322 int success, int behind)
1327 if (atomic_dec_and_test(&bitmap->behind_writes))
1328 wake_up(&bitmap->behind_wait);
1329 pr_debug("dec write-behind count %d/%lu\n",
1330 atomic_read(&bitmap->behind_writes),
1331 bitmap->mddev->bitmap_info.max_write_behind);
1336 unsigned long flags;
1337 bitmap_counter_t *bmc;
1339 spin_lock_irqsave(&bitmap->counts.lock, flags);
1340 bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1342 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1346 if (success && !bitmap->mddev->degraded &&
1347 bitmap->events_cleared < bitmap->mddev->events) {
1348 bitmap->events_cleared = bitmap->mddev->events;
1349 bitmap->need_sync = 1;
1350 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1353 if (!success && !NEEDED(*bmc))
1354 *bmc |= NEEDED_MASK;
1356 if (COUNTER(*bmc) == COUNTER_MAX)
1357 wake_up(&bitmap->overflow_wait);
1361 bitmap_set_pending(&bitmap->counts, offset);
1362 bitmap->allclean = 0;
1364 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1366 if (sectors > blocks)
1372 EXPORT_SYMBOL(bitmap_endwrite);
1374 static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1377 bitmap_counter_t *bmc;
1379 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1381 return 1; /* always resync if no bitmap */
1383 spin_lock_irq(&bitmap->counts.lock);
1384 bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1390 else if (NEEDED(*bmc)) {
1392 if (!degraded) { /* don't set/clear bits if degraded */
1393 *bmc |= RESYNC_MASK;
1394 *bmc &= ~NEEDED_MASK;
1398 spin_unlock_irq(&bitmap->counts.lock);
1402 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1405 /* bitmap_start_sync must always report on multiples of whole
1406 * pages, otherwise resync (which is very PAGE_SIZE based) will
1408 * So call __bitmap_start_sync repeatedly (if needed) until
1409 * At least PAGE_SIZE>>9 blocks are covered.
1410 * Return the 'or' of the result.
1416 while (*blocks < (PAGE_SIZE>>9)) {
1417 rv |= __bitmap_start_sync(bitmap, offset,
1418 &blocks1, degraded);
1424 EXPORT_SYMBOL(bitmap_start_sync);
1426 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1428 bitmap_counter_t *bmc;
1429 unsigned long flags;
1431 if (bitmap == NULL) {
1435 spin_lock_irqsave(&bitmap->counts.lock, flags);
1436 bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1441 *bmc &= ~RESYNC_MASK;
1443 if (!NEEDED(*bmc) && aborted)
1444 *bmc |= NEEDED_MASK;
1447 bitmap_set_pending(&bitmap->counts, offset);
1448 bitmap->allclean = 0;
1453 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1455 EXPORT_SYMBOL(bitmap_end_sync);
1457 void bitmap_close_sync(struct bitmap *bitmap)
1459 /* Sync has finished, and any bitmap chunks that weren't synced
1460 * properly have been aborted. It remains to us to clear the
1461 * RESYNC bit wherever it is still on
1463 sector_t sector = 0;
1467 while (sector < bitmap->mddev->resync_max_sectors) {
1468 bitmap_end_sync(bitmap, sector, &blocks, 0);
1472 EXPORT_SYMBOL(bitmap_close_sync);
1474 void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
1482 bitmap->last_end_sync = jiffies;
1485 if (time_before(jiffies, (bitmap->last_end_sync
1486 + bitmap->mddev->bitmap_info.daemon_sleep)))
1488 wait_event(bitmap->mddev->recovery_wait,
1489 atomic_read(&bitmap->mddev->recovery_active) == 0);
1491 bitmap->mddev->curr_resync_completed = sector;
1492 set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1493 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1495 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1496 bitmap_end_sync(bitmap, s, &blocks, 0);
1499 bitmap->last_end_sync = jiffies;
1500 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1502 EXPORT_SYMBOL(bitmap_cond_end_sync);
1504 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1506 /* For each chunk covered by any of these sectors, set the
1507 * counter to 2 and possibly set resync_needed. They should all
1508 * be 0 at this point
1512 bitmap_counter_t *bmc;
1513 spin_lock_irq(&bitmap->counts.lock);
1514 bmc = bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1516 spin_unlock_irq(&bitmap->counts.lock);
1520 *bmc = 2 | (needed ? NEEDED_MASK : 0);
1521 bitmap_count_page(&bitmap->counts, offset, 1);
1522 bitmap_set_pending(&bitmap->counts, offset);
1523 bitmap->allclean = 0;
1525 spin_unlock_irq(&bitmap->counts.lock);
1528 /* dirty the memory and file bits for bitmap chunks "s" to "e" */
1529 void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1531 unsigned long chunk;
1533 for (chunk = s; chunk <= e; chunk++) {
1534 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1535 bitmap_set_memory_bits(bitmap, sec, 1);
1536 bitmap_file_set_bit(bitmap, sec);
1537 if (sec < bitmap->mddev->recovery_cp)
1538 /* We are asserting that the array is dirty,
1539 * so move the recovery_cp address back so
1540 * that it is obvious that it is dirty
1542 bitmap->mddev->recovery_cp = sec;
1547 * flush out any pending updates
1549 void bitmap_flush(struct mddev *mddev)
1551 struct bitmap *bitmap = mddev->bitmap;
1554 if (!bitmap) /* there was no bitmap */
1557 /* run the daemon_work three time to ensure everything is flushed
1560 sleep = mddev->bitmap_info.daemon_sleep * 2;
1561 bitmap->daemon_lastrun -= sleep;
1562 bitmap_daemon_work(mddev);
1563 bitmap->daemon_lastrun -= sleep;
1564 bitmap_daemon_work(mddev);
1565 bitmap->daemon_lastrun -= sleep;
1566 bitmap_daemon_work(mddev);
1567 bitmap_update_sb(bitmap);
1571 * free memory that was allocated
1573 static void bitmap_free(struct bitmap *bitmap)
1575 unsigned long k, pages;
1576 struct bitmap_page *bp;
1578 if (!bitmap) /* there was no bitmap */
1581 /* Shouldn't be needed - but just in case.... */
1582 wait_event(bitmap->write_wait,
1583 atomic_read(&bitmap->pending_writes) == 0);
1585 /* release the bitmap file */
1586 bitmap_file_unmap(&bitmap->storage);
1588 bp = bitmap->counts.bp;
1589 pages = bitmap->counts.pages;
1591 /* free all allocated memory */
1593 if (bp) /* deallocate the page memory */
1594 for (k = 0; k < pages; k++)
1595 if (bp[k].map && !bp[k].hijacked)
1601 void bitmap_destroy(struct mddev *mddev)
1603 struct bitmap *bitmap = mddev->bitmap;
1605 if (!bitmap) /* there was no bitmap */
1608 mutex_lock(&mddev->bitmap_info.mutex);
1609 mddev->bitmap = NULL; /* disconnect from the md device */
1610 mutex_unlock(&mddev->bitmap_info.mutex);
1612 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1614 if (bitmap->sysfs_can_clear)
1615 sysfs_put(bitmap->sysfs_can_clear);
1617 bitmap_free(bitmap);
1621 * initialize the bitmap structure
1622 * if this returns an error, bitmap_destroy must be called to do clean up
1624 int bitmap_create(struct mddev *mddev)
1626 struct bitmap *bitmap;
1627 sector_t blocks = mddev->resync_max_sectors;
1628 struct file *file = mddev->bitmap_info.file;
1630 struct kernfs_node *bm = NULL;
1632 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1634 BUG_ON(file && mddev->bitmap_info.offset);
1636 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1640 spin_lock_init(&bitmap->counts.lock);
1641 atomic_set(&bitmap->pending_writes, 0);
1642 init_waitqueue_head(&bitmap->write_wait);
1643 init_waitqueue_head(&bitmap->overflow_wait);
1644 init_waitqueue_head(&bitmap->behind_wait);
1646 bitmap->mddev = mddev;
1649 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
1651 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
1654 bitmap->sysfs_can_clear = NULL;
1656 bitmap->storage.file = file;
1659 /* As future accesses to this file will use bmap,
1660 * and bypass the page cache, we must sync the file
1665 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1666 if (!mddev->bitmap_info.external) {
1668 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1669 * instructing us to create a new on-disk bitmap instance.
1671 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1672 err = bitmap_new_disk_sb(bitmap);
1674 err = bitmap_read_sb(bitmap);
1677 if (mddev->bitmap_info.chunksize == 0 ||
1678 mddev->bitmap_info.daemon_sleep == 0)
1679 /* chunksize and time_base need to be
1686 bitmap->daemon_lastrun = jiffies;
1687 err = bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1691 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1692 bitmap->counts.pages, bmname(bitmap));
1694 mddev->bitmap = bitmap;
1695 return test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1698 bitmap_free(bitmap);
1702 int bitmap_load(struct mddev *mddev)
1706 sector_t sector = 0;
1707 struct bitmap *bitmap = mddev->bitmap;
1712 /* Clear out old bitmap info first: Either there is none, or we
1713 * are resuming after someone else has possibly changed things,
1714 * so we should forget old cached info.
1715 * All chunks should be clean, but some might need_sync.
1717 while (sector < mddev->resync_max_sectors) {
1719 bitmap_start_sync(bitmap, sector, &blocks, 0);
1722 bitmap_close_sync(bitmap);
1724 if (mddev->degraded == 0
1725 || bitmap->events_cleared == mddev->events)
1726 /* no need to keep dirty bits to optimise a
1727 * re-add of a missing device */
1728 start = mddev->recovery_cp;
1730 mutex_lock(&mddev->bitmap_info.mutex);
1731 err = bitmap_init_from_disk(bitmap, start);
1732 mutex_unlock(&mddev->bitmap_info.mutex);
1736 clear_bit(BITMAP_STALE, &bitmap->flags);
1738 /* Kick recovery in case any bits were set */
1739 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1741 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1742 md_wakeup_thread(mddev->thread);
1744 bitmap_update_sb(bitmap);
1746 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1751 EXPORT_SYMBOL_GPL(bitmap_load);
1753 void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
1755 unsigned long chunk_kb;
1756 struct bitmap_counts *counts;
1761 counts = &bitmap->counts;
1763 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
1764 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
1766 counts->pages - counts->missing_pages,
1768 (counts->pages - counts->missing_pages)
1769 << (PAGE_SHIFT - 10),
1770 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
1771 chunk_kb ? "KB" : "B");
1772 if (bitmap->storage.file) {
1773 seq_printf(seq, ", file: ");
1774 seq_path(seq, &bitmap->storage.file->f_path, " \t\n");
1777 seq_printf(seq, "\n");
1780 int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
1781 int chunksize, int init)
1783 /* If chunk_size is 0, choose an appropriate chunk size.
1784 * Then possibly allocate new storage space.
1785 * Then quiesce, copy bits, replace bitmap, and re-start
1787 * This function is called both to set up the initial bitmap
1788 * and to resize the bitmap while the array is active.
1789 * If this happens as a result of the array being resized,
1790 * chunksize will be zero, and we need to choose a suitable
1791 * chunksize, otherwise we use what we are given.
1793 struct bitmap_storage store;
1794 struct bitmap_counts old_counts;
1795 unsigned long chunks;
1797 sector_t old_blocks, new_blocks;
1801 struct bitmap_page *new_bp;
1803 if (chunksize == 0) {
1804 /* If there is enough space, leave the chunk size unchanged,
1805 * else increase by factor of two until there is enough space.
1808 long space = bitmap->mddev->bitmap_info.space;
1811 /* We don't know how much space there is, so limit
1812 * to current size - in sectors.
1814 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
1815 if (!bitmap->mddev->bitmap_info.external)
1816 bytes += sizeof(bitmap_super_t);
1817 space = DIV_ROUND_UP(bytes, 512);
1818 bitmap->mddev->bitmap_info.space = space;
1820 chunkshift = bitmap->counts.chunkshift;
1823 /* 'chunkshift' is shift from block size to chunk size */
1825 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
1826 bytes = DIV_ROUND_UP(chunks, 8);
1827 if (!bitmap->mddev->bitmap_info.external)
1828 bytes += sizeof(bitmap_super_t);
1829 } while (bytes > (space << 9));
1831 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
1833 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
1834 memset(&store, 0, sizeof(store));
1835 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
1836 ret = bitmap_storage_alloc(&store, chunks,
1837 !bitmap->mddev->bitmap_info.external);
1841 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
1843 new_bp = kzalloc(pages * sizeof(*new_bp), GFP_KERNEL);
1846 bitmap_file_unmap(&store);
1851 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
1853 store.file = bitmap->storage.file;
1854 bitmap->storage.file = NULL;
1856 if (store.sb_page && bitmap->storage.sb_page)
1857 memcpy(page_address(store.sb_page),
1858 page_address(bitmap->storage.sb_page),
1859 sizeof(bitmap_super_t));
1860 bitmap_file_unmap(&bitmap->storage);
1861 bitmap->storage = store;
1863 old_counts = bitmap->counts;
1864 bitmap->counts.bp = new_bp;
1865 bitmap->counts.pages = pages;
1866 bitmap->counts.missing_pages = pages;
1867 bitmap->counts.chunkshift = chunkshift;
1868 bitmap->counts.chunks = chunks;
1869 bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift +
1870 BITMAP_BLOCK_SHIFT);
1872 blocks = min(old_counts.chunks << old_counts.chunkshift,
1873 chunks << chunkshift);
1875 spin_lock_irq(&bitmap->counts.lock);
1876 for (block = 0; block < blocks; ) {
1877 bitmap_counter_t *bmc_old, *bmc_new;
1880 bmc_old = bitmap_get_counter(&old_counts, block,
1882 set = bmc_old && NEEDED(*bmc_old);
1885 bmc_new = bitmap_get_counter(&bitmap->counts, block,
1887 if (*bmc_new == 0) {
1888 /* need to set on-disk bits too. */
1889 sector_t end = block + new_blocks;
1890 sector_t start = block >> chunkshift;
1891 start <<= chunkshift;
1892 while (start < end) {
1893 bitmap_file_set_bit(bitmap, block);
1894 start += 1 << chunkshift;
1897 bitmap_count_page(&bitmap->counts,
1899 bitmap_set_pending(&bitmap->counts,
1902 *bmc_new |= NEEDED_MASK;
1903 if (new_blocks < old_blocks)
1904 old_blocks = new_blocks;
1906 block += old_blocks;
1911 while (block < (chunks << chunkshift)) {
1912 bitmap_counter_t *bmc;
1913 bmc = bitmap_get_counter(&bitmap->counts, block,
1916 /* new space. It needs to be resynced, so
1917 * we set NEEDED_MASK.
1920 *bmc = NEEDED_MASK | 2;
1921 bitmap_count_page(&bitmap->counts,
1923 bitmap_set_pending(&bitmap->counts,
1927 block += new_blocks;
1929 for (i = 0; i < bitmap->storage.file_pages; i++)
1930 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1932 spin_unlock_irq(&bitmap->counts.lock);
1935 bitmap_unplug(bitmap);
1936 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
1942 EXPORT_SYMBOL_GPL(bitmap_resize);
1945 location_show(struct mddev *mddev, char *page)
1948 if (mddev->bitmap_info.file)
1949 len = sprintf(page, "file");
1950 else if (mddev->bitmap_info.offset)
1951 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
1953 len = sprintf(page, "none");
1954 len += sprintf(page+len, "\n");
1959 location_store(struct mddev *mddev, const char *buf, size_t len)
1963 if (!mddev->pers->quiesce)
1965 if (mddev->recovery || mddev->sync_thread)
1969 if (mddev->bitmap || mddev->bitmap_info.file ||
1970 mddev->bitmap_info.offset) {
1971 /* bitmap already configured. Only option is to clear it */
1972 if (strncmp(buf, "none", 4) != 0)
1975 mddev->pers->quiesce(mddev, 1);
1976 bitmap_destroy(mddev);
1977 mddev->pers->quiesce(mddev, 0);
1979 mddev->bitmap_info.offset = 0;
1980 if (mddev->bitmap_info.file) {
1981 struct file *f = mddev->bitmap_info.file;
1982 mddev->bitmap_info.file = NULL;
1986 /* No bitmap, OK to set a location */
1988 if (strncmp(buf, "none", 4) == 0)
1989 /* nothing to be done */;
1990 else if (strncmp(buf, "file:", 5) == 0) {
1991 /* Not supported yet */
1996 rv = kstrtoll(buf+1, 10, &offset);
1998 rv = kstrtoll(buf, 10, &offset);
2003 if (mddev->bitmap_info.external == 0 &&
2004 mddev->major_version == 0 &&
2005 offset != mddev->bitmap_info.default_offset)
2007 mddev->bitmap_info.offset = offset;
2009 mddev->pers->quiesce(mddev, 1);
2010 rv = bitmap_create(mddev);
2012 rv = bitmap_load(mddev);
2014 bitmap_destroy(mddev);
2015 mddev->bitmap_info.offset = 0;
2017 mddev->pers->quiesce(mddev, 0);
2023 if (!mddev->external) {
2024 /* Ensure new bitmap info is stored in
2025 * metadata promptly.
2027 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2028 md_wakeup_thread(mddev->thread);
2033 static struct md_sysfs_entry bitmap_location =
2034 __ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2036 /* 'bitmap/space' is the space available at 'location' for the
2037 * bitmap. This allows the kernel to know when it is safe to
2038 * resize the bitmap to match a resized array.
2041 space_show(struct mddev *mddev, char *page)
2043 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2047 space_store(struct mddev *mddev, const char *buf, size_t len)
2049 unsigned long sectors;
2052 rv = kstrtoul(buf, 10, §ors);
2059 if (mddev->bitmap &&
2060 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2061 return -EFBIG; /* Bitmap is too big for this small space */
2063 /* could make sure it isn't too big, but that isn't really
2064 * needed - user-space should be careful.
2066 mddev->bitmap_info.space = sectors;
2070 static struct md_sysfs_entry bitmap_space =
2071 __ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2074 timeout_show(struct mddev *mddev, char *page)
2077 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2078 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2080 len = sprintf(page, "%lu", secs);
2082 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2083 len += sprintf(page+len, "\n");
2088 timeout_store(struct mddev *mddev, const char *buf, size_t len)
2090 /* timeout can be set at any time */
2091 unsigned long timeout;
2092 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2096 /* just to make sure we don't overflow... */
2097 if (timeout >= LONG_MAX / HZ)
2100 timeout = timeout * HZ / 10000;
2102 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2103 timeout = MAX_SCHEDULE_TIMEOUT-1;
2106 mddev->bitmap_info.daemon_sleep = timeout;
2107 if (mddev->thread) {
2108 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
2109 * the bitmap is all clean and we don't need to
2110 * adjust the timeout right now
2112 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2113 mddev->thread->timeout = timeout;
2114 md_wakeup_thread(mddev->thread);
2120 static struct md_sysfs_entry bitmap_timeout =
2121 __ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2124 backlog_show(struct mddev *mddev, char *page)
2126 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2130 backlog_store(struct mddev *mddev, const char *buf, size_t len)
2132 unsigned long backlog;
2133 int rv = kstrtoul(buf, 10, &backlog);
2136 if (backlog > COUNTER_MAX)
2138 mddev->bitmap_info.max_write_behind = backlog;
2142 static struct md_sysfs_entry bitmap_backlog =
2143 __ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2146 chunksize_show(struct mddev *mddev, char *page)
2148 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2152 chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2154 /* Can only be changed when no bitmap is active */
2156 unsigned long csize;
2159 rv = kstrtoul(buf, 10, &csize);
2163 !is_power_of_2(csize))
2165 mddev->bitmap_info.chunksize = csize;
2169 static struct md_sysfs_entry bitmap_chunksize =
2170 __ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2172 static ssize_t metadata_show(struct mddev *mddev, char *page)
2174 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2175 ? "external" : "internal"));
2178 static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2180 if (mddev->bitmap ||
2181 mddev->bitmap_info.file ||
2182 mddev->bitmap_info.offset)
2184 if (strncmp(buf, "external", 8) == 0)
2185 mddev->bitmap_info.external = 1;
2186 else if (strncmp(buf, "internal", 8) == 0)
2187 mddev->bitmap_info.external = 0;
2193 static struct md_sysfs_entry bitmap_metadata =
2194 __ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2196 static ssize_t can_clear_show(struct mddev *mddev, char *page)
2200 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2203 len = sprintf(page, "\n");
2207 static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2209 if (mddev->bitmap == NULL)
2211 if (strncmp(buf, "false", 5) == 0)
2212 mddev->bitmap->need_sync = 1;
2213 else if (strncmp(buf, "true", 4) == 0) {
2214 if (mddev->degraded)
2216 mddev->bitmap->need_sync = 0;
2222 static struct md_sysfs_entry bitmap_can_clear =
2223 __ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2226 behind_writes_used_show(struct mddev *mddev, char *page)
2228 if (mddev->bitmap == NULL)
2229 return sprintf(page, "0\n");
2230 return sprintf(page, "%lu\n",
2231 mddev->bitmap->behind_writes_used);
2235 behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2238 mddev->bitmap->behind_writes_used = 0;
2242 static struct md_sysfs_entry max_backlog_used =
2243 __ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2244 behind_writes_used_show, behind_writes_used_reset);
2246 static struct attribute *md_bitmap_attrs[] = {
2247 &bitmap_location.attr,
2249 &bitmap_timeout.attr,
2250 &bitmap_backlog.attr,
2251 &bitmap_chunksize.attr,
2252 &bitmap_metadata.attr,
2253 &bitmap_can_clear.attr,
2254 &max_backlog_used.attr,
2257 struct attribute_group md_bitmap_group = {
2259 .attrs = md_bitmap_attrs,