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 /* It is possible that this is being called inside a
76 * prepare_to_wait/finish_wait loop from raid5c:make_request().
77 * In general it is not permitted to sleep in that context as it
78 * can cause the loop to spin freely.
79 * That doesn't apply here as we can only reach this point
81 * When this function completes, either bp[page].map or
82 * bp[page].hijacked. In either case, this function will
83 * abort before getting to this point again. So there is
84 * no risk of a free-spin, and so it is safe to assert
85 * that sleeping here is allowed.
87 sched_annotate_sleep();
88 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
89 spin_lock_irq(&bitmap->lock);
91 if (mappage == NULL) {
92 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
93 /* failed - set the hijacked flag so that we can use the
94 * pointer as a counter */
95 if (!bitmap->bp[page].map)
96 bitmap->bp[page].hijacked = 1;
97 } else if (bitmap->bp[page].map ||
98 bitmap->bp[page].hijacked) {
99 /* somebody beat us to getting the page */
104 /* no page was in place and we have one, so install it */
106 bitmap->bp[page].map = mappage;
107 bitmap->missing_pages--;
112 /* if page is completely empty, put it back on the free list, or dealloc it */
113 /* if page was hijacked, unmark the flag so it might get alloced next time */
114 /* Note: lock should be held when calling this */
115 static void bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
119 if (bitmap->bp[page].count) /* page is still busy */
122 /* page is no longer in use, it can be released */
124 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
125 bitmap->bp[page].hijacked = 0;
126 bitmap->bp[page].map = NULL;
128 /* normal case, free the page */
129 ptr = bitmap->bp[page].map;
130 bitmap->bp[page].map = NULL;
131 bitmap->missing_pages++;
137 * bitmap file handling - read and write the bitmap file and its superblock
141 * basic page I/O operations
144 /* IO operations when bitmap is stored near all superblocks */
145 static int read_sb_page(struct mddev *mddev, loff_t offset,
147 unsigned long index, int size)
149 /* choose a good rdev and read the page from there */
151 struct md_rdev *rdev;
154 rdev_for_each(rdev, mddev) {
155 if (! test_bit(In_sync, &rdev->flags)
156 || test_bit(Faulty, &rdev->flags))
159 target = offset + index * (PAGE_SIZE/512);
161 if (sync_page_io(rdev, target,
162 roundup(size, bdev_logical_block_size(rdev->bdev)),
171 static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
173 /* Iterate the disks of an mddev, using rcu to protect access to the
174 * linked list, and raising the refcount of devices we return to ensure
175 * they don't disappear while in use.
176 * As devices are only added or removed when raid_disk is < 0 and
177 * nr_pending is 0 and In_sync is clear, the entries we return will
178 * still be in the same position on the list when we re-enter
179 * list_for_each_entry_continue_rcu.
181 * Note that if entered with 'rdev == NULL' to start at the
182 * beginning, we temporarily assign 'rdev' to an address which
183 * isn't really an rdev, but which can be used by
184 * list_for_each_entry_continue_rcu() to find the first entry.
188 /* start at the beginning */
189 rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
191 /* release the previous rdev and start from there. */
192 rdev_dec_pending(rdev, mddev);
194 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
195 if (rdev->raid_disk >= 0 &&
196 !test_bit(Faulty, &rdev->flags)) {
197 /* this is a usable devices */
198 atomic_inc(&rdev->nr_pending);
207 static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
209 struct md_rdev *rdev = NULL;
210 struct block_device *bdev;
211 struct mddev *mddev = bitmap->mddev;
212 struct bitmap_storage *store = &bitmap->storage;
215 if (mddev_is_clustered(bitmap->mddev))
216 node_offset = bitmap->cluster_slot * store->file_pages;
218 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
219 int size = PAGE_SIZE;
220 loff_t offset = mddev->bitmap_info.offset;
222 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
224 if (page->index == store->file_pages-1) {
225 int last_page_size = store->bytes & (PAGE_SIZE-1);
226 if (last_page_size == 0)
227 last_page_size = PAGE_SIZE;
228 size = roundup(last_page_size,
229 bdev_logical_block_size(bdev));
231 /* Just make sure we aren't corrupting data or
234 if (mddev->external) {
235 /* Bitmap could be anywhere. */
236 if (rdev->sb_start + offset + (page->index
240 rdev->sb_start + offset
241 < (rdev->data_offset + mddev->dev_sectors
244 } else if (offset < 0) {
245 /* DATA BITMAP METADATA */
247 + (long)(page->index * (PAGE_SIZE/512))
249 /* bitmap runs in to metadata */
251 if (rdev->data_offset + mddev->dev_sectors
252 > rdev->sb_start + offset)
253 /* data runs in to bitmap */
255 } else if (rdev->sb_start < rdev->data_offset) {
256 /* METADATA BITMAP DATA */
259 + page->index*(PAGE_SIZE/512) + size/512
261 /* bitmap runs in to data */
264 /* DATA METADATA BITMAP - no problems */
266 md_super_write(mddev, rdev,
267 rdev->sb_start + offset
268 + page->index * (PAGE_SIZE/512),
274 md_super_wait(mddev);
281 static void bitmap_file_kick(struct bitmap *bitmap);
283 * write out a page to a file
285 static void write_page(struct bitmap *bitmap, struct page *page, int wait)
287 struct buffer_head *bh;
289 if (bitmap->storage.file == NULL) {
290 switch (write_sb_page(bitmap, page, wait)) {
292 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
296 bh = page_buffers(page);
298 while (bh && bh->b_blocknr) {
299 atomic_inc(&bitmap->pending_writes);
300 set_buffer_locked(bh);
301 set_buffer_mapped(bh);
302 submit_bh(WRITE | REQ_SYNC, bh);
303 bh = bh->b_this_page;
307 wait_event(bitmap->write_wait,
308 atomic_read(&bitmap->pending_writes)==0);
310 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
311 bitmap_file_kick(bitmap);
314 static void end_bitmap_write(struct buffer_head *bh, int uptodate)
316 struct bitmap *bitmap = bh->b_private;
319 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
320 if (atomic_dec_and_test(&bitmap->pending_writes))
321 wake_up(&bitmap->write_wait);
324 /* copied from buffer.c */
326 __clear_page_buffers(struct page *page)
328 ClearPagePrivate(page);
329 set_page_private(page, 0);
330 page_cache_release(page);
332 static void free_buffers(struct page *page)
334 struct buffer_head *bh;
336 if (!PagePrivate(page))
339 bh = page_buffers(page);
341 struct buffer_head *next = bh->b_this_page;
342 free_buffer_head(bh);
345 __clear_page_buffers(page);
349 /* read a page from a file.
350 * We both read the page, and attach buffers to the page to record the
351 * address of each block (using bmap). These addresses will be used
352 * to write the block later, completely bypassing the filesystem.
353 * This usage is similar to how swap files are handled, and allows us
354 * to write to a file with no concerns of memory allocation failing.
356 static int read_page(struct file *file, unsigned long index,
357 struct bitmap *bitmap,
362 struct inode *inode = file_inode(file);
363 struct buffer_head *bh;
366 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
367 (unsigned long long)index << PAGE_SHIFT);
369 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
374 attach_page_buffers(page, bh);
375 block = index << (PAGE_SHIFT - inode->i_blkbits);
380 bh->b_blocknr = bmap(inode, block);
381 if (bh->b_blocknr == 0) {
382 /* Cannot use this file! */
386 bh->b_bdev = inode->i_sb->s_bdev;
387 if (count < (1<<inode->i_blkbits))
390 count -= (1<<inode->i_blkbits);
392 bh->b_end_io = end_bitmap_write;
393 bh->b_private = bitmap;
394 atomic_inc(&bitmap->pending_writes);
395 set_buffer_locked(bh);
396 set_buffer_mapped(bh);
400 bh = bh->b_this_page;
404 wait_event(bitmap->write_wait,
405 atomic_read(&bitmap->pending_writes)==0);
406 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
410 printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %d\n",
412 (unsigned long long)index << PAGE_SHIFT,
418 * bitmap file superblock operations
421 /* update the event counter and sync the superblock to disk */
422 void bitmap_update_sb(struct bitmap *bitmap)
426 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
428 if (bitmap->mddev->bitmap_info.external)
430 if (!bitmap->storage.sb_page) /* no superblock */
432 sb = kmap_atomic(bitmap->storage.sb_page);
433 sb->events = cpu_to_le64(bitmap->mddev->events);
434 if (bitmap->mddev->events < bitmap->events_cleared)
435 /* rocking back to read-only */
436 bitmap->events_cleared = bitmap->mddev->events;
437 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
438 sb->state = cpu_to_le32(bitmap->flags);
439 /* Just in case these have been changed via sysfs: */
440 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
441 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
442 /* This might have been changed by a reshape */
443 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
444 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
445 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
446 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
449 write_page(bitmap, bitmap->storage.sb_page, 1);
452 /* print out the bitmap file superblock */
453 void bitmap_print_sb(struct bitmap *bitmap)
457 if (!bitmap || !bitmap->storage.sb_page)
459 sb = kmap_atomic(bitmap->storage.sb_page);
460 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
461 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
462 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
463 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
464 *(__u32 *)(sb->uuid+0),
465 *(__u32 *)(sb->uuid+4),
466 *(__u32 *)(sb->uuid+8),
467 *(__u32 *)(sb->uuid+12));
468 printk(KERN_DEBUG " events: %llu\n",
469 (unsigned long long) le64_to_cpu(sb->events));
470 printk(KERN_DEBUG "events cleared: %llu\n",
471 (unsigned long long) le64_to_cpu(sb->events_cleared));
472 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
473 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
474 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
475 printk(KERN_DEBUG " sync size: %llu KB\n",
476 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
477 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
485 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
486 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
487 * This function verifies 'bitmap_info' and populates the on-disk bitmap
488 * structure, which is to be written to disk.
490 * Returns: 0 on success, -Exxx on error
492 static int bitmap_new_disk_sb(struct bitmap *bitmap)
495 unsigned long chunksize, daemon_sleep, write_behind;
497 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
498 if (bitmap->storage.sb_page == NULL)
500 bitmap->storage.sb_page->index = 0;
502 sb = kmap_atomic(bitmap->storage.sb_page);
504 sb->magic = cpu_to_le32(BITMAP_MAGIC);
505 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
507 chunksize = bitmap->mddev->bitmap_info.chunksize;
509 if (!is_power_of_2(chunksize)) {
511 printk(KERN_ERR "bitmap chunksize not a power of 2\n");
514 sb->chunksize = cpu_to_le32(chunksize);
516 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
518 (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
519 printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
520 daemon_sleep = 5 * HZ;
522 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
523 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
526 * FIXME: write_behind for RAID1. If not specified, what
527 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
529 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
530 if (write_behind > COUNTER_MAX)
531 write_behind = COUNTER_MAX / 2;
532 sb->write_behind = cpu_to_le32(write_behind);
533 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
535 /* keep the array size field of the bitmap superblock up to date */
536 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
538 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
540 set_bit(BITMAP_STALE, &bitmap->flags);
541 sb->state = cpu_to_le32(bitmap->flags);
542 bitmap->events_cleared = bitmap->mddev->events;
543 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
544 bitmap->mddev->bitmap_info.nodes = 0;
551 /* read the superblock from the bitmap file and initialize some bitmap fields */
552 static int bitmap_read_sb(struct bitmap *bitmap)
556 unsigned long chunksize, daemon_sleep, write_behind;
557 unsigned long long events;
559 unsigned long sectors_reserved = 0;
561 struct page *sb_page;
563 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
564 chunksize = 128 * 1024 * 1024;
565 daemon_sleep = 5 * HZ;
567 set_bit(BITMAP_STALE, &bitmap->flags);
571 /* page 0 is the superblock, read it... */
572 sb_page = alloc_page(GFP_KERNEL);
575 bitmap->storage.sb_page = sb_page;
578 /* If cluster_slot is set, the cluster is setup */
579 if (bitmap->cluster_slot >= 0) {
580 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
582 sector_div(bm_blocks,
583 bitmap->mddev->bitmap_info.chunksize >> 9);
585 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
587 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
588 bitmap->mddev->bitmap_info.offset += bitmap->cluster_slot * (bm_blocks << 3);
589 pr_info("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
590 bitmap->cluster_slot, (unsigned long long)bitmap->mddev->bitmap_info.offset);
593 if (bitmap->storage.file) {
594 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
595 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
597 err = read_page(bitmap->storage.file, 0,
598 bitmap, bytes, sb_page);
600 err = read_sb_page(bitmap->mddev,
601 bitmap->mddev->bitmap_info.offset,
603 0, sizeof(bitmap_super_t));
609 sb = kmap_atomic(sb_page);
611 chunksize = le32_to_cpu(sb->chunksize);
612 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
613 write_behind = le32_to_cpu(sb->write_behind);
614 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
615 /* XXX: This is a hack to ensure that we don't use clustering
617 * - dm-raid is in use and
618 * - the nodes written in bitmap_sb is erroneous.
620 if (!bitmap->mddev->sync_super) {
621 nodes = le32_to_cpu(sb->nodes);
622 strlcpy(bitmap->mddev->bitmap_info.cluster_name,
623 sb->cluster_name, 64);
626 /* verify that the bitmap-specific fields are valid */
627 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
628 reason = "bad magic";
629 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
630 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
631 reason = "unrecognized superblock version";
632 else if (chunksize < 512)
633 reason = "bitmap chunksize too small";
634 else if (!is_power_of_2(chunksize))
635 reason = "bitmap chunksize not a power of 2";
636 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
637 reason = "daemon sleep period out of range";
638 else if (write_behind > COUNTER_MAX)
639 reason = "write-behind limit out of range (0 - 16383)";
641 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
642 bmname(bitmap), reason);
646 /* keep the array size field of the bitmap superblock up to date */
647 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
649 if (bitmap->mddev->persistent) {
651 * We have a persistent array superblock, so compare the
652 * bitmap's UUID and event counter to the mddev's
654 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
656 "%s: bitmap superblock UUID mismatch\n",
660 events = le64_to_cpu(sb->events);
661 if (!nodes && (events < bitmap->mddev->events)) {
663 "%s: bitmap file is out of date (%llu < %llu) "
664 "-- forcing full recovery\n",
665 bmname(bitmap), events,
666 (unsigned long long) bitmap->mddev->events);
667 set_bit(BITMAP_STALE, &bitmap->flags);
671 /* assign fields using values from superblock */
672 bitmap->flags |= le32_to_cpu(sb->state);
673 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
674 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
675 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
676 strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
681 /* Assiging chunksize is required for "re_read" */
682 bitmap->mddev->bitmap_info.chunksize = chunksize;
683 if (nodes && (bitmap->cluster_slot < 0)) {
684 err = md_setup_cluster(bitmap->mddev, nodes);
686 pr_err("%s: Could not setup cluster service (%d)\n",
687 bmname(bitmap), err);
690 bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
696 if (test_bit(BITMAP_STALE, &bitmap->flags))
697 bitmap->events_cleared = bitmap->mddev->events;
698 bitmap->mddev->bitmap_info.chunksize = chunksize;
699 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
700 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
701 bitmap->mddev->bitmap_info.nodes = nodes;
702 if (bitmap->mddev->bitmap_info.space == 0 ||
703 bitmap->mddev->bitmap_info.space > sectors_reserved)
704 bitmap->mddev->bitmap_info.space = sectors_reserved;
706 bitmap_print_sb(bitmap);
707 if (bitmap->cluster_slot < 0)
708 md_cluster_stop(bitmap->mddev);
714 * general bitmap file operations
720 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
721 * file a page at a time. There's a superblock at the start of the file.
723 /* calculate the index of the page that contains this bit */
724 static inline unsigned long file_page_index(struct bitmap_storage *store,
728 chunk += sizeof(bitmap_super_t) << 3;
729 return chunk >> PAGE_BIT_SHIFT;
732 /* calculate the (bit) offset of this bit within a page */
733 static inline unsigned long file_page_offset(struct bitmap_storage *store,
737 chunk += sizeof(bitmap_super_t) << 3;
738 return chunk & (PAGE_BITS - 1);
742 * return a pointer to the page in the filemap that contains the given bit
745 static inline struct page *filemap_get_page(struct bitmap_storage *store,
748 if (file_page_index(store, chunk) >= store->file_pages)
750 return store->filemap[file_page_index(store, chunk)];
753 static int bitmap_storage_alloc(struct bitmap_storage *store,
754 unsigned long chunks, int with_super,
757 int pnum, offset = 0;
758 unsigned long num_pages;
761 bytes = DIV_ROUND_UP(chunks, 8);
763 bytes += sizeof(bitmap_super_t);
765 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
766 offset = slot_number * (num_pages - 1);
768 store->filemap = kmalloc(sizeof(struct page *)
769 * num_pages, GFP_KERNEL);
773 if (with_super && !store->sb_page) {
774 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
775 if (store->sb_page == NULL)
780 if (store->sb_page) {
781 store->filemap[0] = store->sb_page;
783 store->sb_page->index = offset;
786 for ( ; pnum < num_pages; pnum++) {
787 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
788 if (!store->filemap[pnum]) {
789 store->file_pages = pnum;
792 store->filemap[pnum]->index = pnum + offset;
794 store->file_pages = pnum;
796 /* We need 4 bits per page, rounded up to a multiple
797 * of sizeof(unsigned long) */
798 store->filemap_attr = kzalloc(
799 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
801 if (!store->filemap_attr)
804 store->bytes = bytes;
809 static void bitmap_file_unmap(struct bitmap_storage *store)
811 struct page **map, *sb_page;
816 map = store->filemap;
817 pages = store->file_pages;
818 sb_page = store->sb_page;
821 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
822 free_buffers(map[pages]);
824 kfree(store->filemap_attr);
827 free_buffers(sb_page);
830 struct inode *inode = file_inode(file);
831 invalidate_mapping_pages(inode->i_mapping, 0, -1);
837 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
838 * then it is no longer reliable, so we stop using it and we mark the file
839 * as failed in the superblock
841 static void bitmap_file_kick(struct bitmap *bitmap)
843 char *path, *ptr = NULL;
845 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
846 bitmap_update_sb(bitmap);
848 if (bitmap->storage.file) {
849 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
851 ptr = d_path(&bitmap->storage.file->f_path,
855 "%s: kicking failed bitmap file %s from array!\n",
856 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
861 "%s: disabling internal bitmap due to errors\n",
866 enum bitmap_page_attr {
867 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
868 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
869 * i.e. counter is 1 or 2. */
870 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
873 static inline void set_page_attr(struct bitmap *bitmap, int pnum,
874 enum bitmap_page_attr attr)
876 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
879 static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
880 enum bitmap_page_attr attr)
882 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
885 static inline int test_page_attr(struct bitmap *bitmap, int pnum,
886 enum bitmap_page_attr attr)
888 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
891 static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
892 enum bitmap_page_attr attr)
894 return test_and_clear_bit((pnum<<2) + attr,
895 bitmap->storage.filemap_attr);
898 * bitmap_file_set_bit -- called before performing a write to the md device
899 * to set (and eventually sync) a particular bit in the bitmap file
901 * we set the bit immediately, then we record the page number so that
902 * when an unplug occurs, we can flush the dirty pages out to disk
904 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
909 unsigned long chunk = block >> bitmap->counts.chunkshift;
911 page = filemap_get_page(&bitmap->storage, chunk);
914 bit = file_page_offset(&bitmap->storage, chunk);
917 kaddr = kmap_atomic(page);
918 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
921 set_bit_le(bit, kaddr);
922 kunmap_atomic(kaddr);
923 pr_debug("set file bit %lu page %lu\n", bit, page->index);
924 /* record page number so it gets flushed to disk when unplug occurs */
925 set_page_attr(bitmap, page->index, BITMAP_PAGE_DIRTY);
928 static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
933 unsigned long chunk = block >> bitmap->counts.chunkshift;
935 page = filemap_get_page(&bitmap->storage, chunk);
938 bit = file_page_offset(&bitmap->storage, chunk);
939 paddr = kmap_atomic(page);
940 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
941 clear_bit(bit, paddr);
943 clear_bit_le(bit, paddr);
944 kunmap_atomic(paddr);
945 if (!test_page_attr(bitmap, page->index, BITMAP_PAGE_NEEDWRITE)) {
946 set_page_attr(bitmap, page->index, BITMAP_PAGE_PENDING);
947 bitmap->allclean = 0;
951 static int bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
956 unsigned long chunk = block >> bitmap->counts.chunkshift;
959 page = filemap_get_page(&bitmap->storage, chunk);
962 bit = file_page_offset(&bitmap->storage, chunk);
963 paddr = kmap_atomic(page);
964 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
965 set = test_bit(bit, paddr);
967 set = test_bit_le(bit, paddr);
968 kunmap_atomic(paddr);
973 /* this gets called when the md device is ready to unplug its underlying
974 * (slave) device queues -- before we let any writes go down, we need to
975 * sync the dirty pages of the bitmap file to disk */
976 void bitmap_unplug(struct bitmap *bitmap)
979 int dirty, need_write;
981 if (!bitmap || !bitmap->storage.filemap ||
982 test_bit(BITMAP_STALE, &bitmap->flags))
985 /* look at each page to see if there are any set bits that need to be
986 * flushed out to disk */
987 for (i = 0; i < bitmap->storage.file_pages; i++) {
988 if (!bitmap->storage.filemap)
990 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
991 need_write = test_and_clear_page_attr(bitmap, i,
992 BITMAP_PAGE_NEEDWRITE);
993 if (dirty || need_write) {
994 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
995 write_page(bitmap, bitmap->storage.filemap[i], 0);
998 if (bitmap->storage.file)
999 wait_event(bitmap->write_wait,
1000 atomic_read(&bitmap->pending_writes)==0);
1002 md_super_wait(bitmap->mddev);
1004 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1005 bitmap_file_kick(bitmap);
1007 EXPORT_SYMBOL(bitmap_unplug);
1009 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1010 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
1011 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
1012 * memory mapping of the bitmap file
1014 * if there's no bitmap file, or if the bitmap file had been
1015 * previously kicked from the array, we mark all the bits as
1016 * 1's in order to cause a full resync.
1018 * We ignore all bits for sectors that end earlier than 'start'.
1019 * This is used when reading an out-of-date bitmap...
1021 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1023 unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
1024 struct page *page = NULL;
1025 unsigned long bit_cnt = 0;
1027 unsigned long offset;
1031 struct bitmap_storage *store = &bitmap->storage;
1033 chunks = bitmap->counts.chunks;
1036 if (!file && !bitmap->mddev->bitmap_info.offset) {
1037 /* No permanent bitmap - fill with '1s'. */
1038 store->filemap = NULL;
1039 store->file_pages = 0;
1040 for (i = 0; i < chunks ; i++) {
1041 /* if the disk bit is set, set the memory bit */
1042 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1044 bitmap_set_memory_bits(bitmap,
1045 (sector_t)i << bitmap->counts.chunkshift,
1051 outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1053 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
1054 "recovery\n", bmname(bitmap));
1056 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
1057 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
1059 (unsigned long) i_size_read(file->f_mapping->host),
1066 if (!bitmap->mddev->bitmap_info.external)
1067 offset = sizeof(bitmap_super_t);
1069 if (mddev_is_clustered(bitmap->mddev))
1070 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1072 for (i = 0; i < chunks; i++) {
1074 index = file_page_index(&bitmap->storage, i);
1075 bit = file_page_offset(&bitmap->storage, i);
1076 if (index != oldindex) { /* this is a new page, read it in */
1078 /* unmap the old page, we're done with it */
1079 if (index == store->file_pages-1)
1080 count = store->bytes - index * PAGE_SIZE;
1083 page = store->filemap[index];
1085 ret = read_page(file, index, bitmap,
1090 bitmap->mddev->bitmap_info.offset,
1092 index + node_offset, count);
1101 * if bitmap is out of date, dirty the
1102 * whole page and write it out
1104 paddr = kmap_atomic(page);
1105 memset(paddr + offset, 0xff,
1106 PAGE_SIZE - offset);
1107 kunmap_atomic(paddr);
1108 write_page(bitmap, page, 1);
1111 if (test_bit(BITMAP_WRITE_ERROR,
1116 paddr = kmap_atomic(page);
1117 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1118 b = test_bit(bit, paddr);
1120 b = test_bit_le(bit, paddr);
1121 kunmap_atomic(paddr);
1123 /* if the disk bit is set, set the memory bit */
1124 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1126 bitmap_set_memory_bits(bitmap,
1127 (sector_t)i << bitmap->counts.chunkshift,
1134 printk(KERN_INFO "%s: bitmap initialized from disk: "
1135 "read %lu pages, set %lu of %lu bits\n",
1136 bmname(bitmap), store->file_pages,
1142 printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1143 bmname(bitmap), ret);
1147 void bitmap_write_all(struct bitmap *bitmap)
1149 /* We don't actually write all bitmap blocks here,
1150 * just flag them as needing to be written
1154 if (!bitmap || !bitmap->storage.filemap)
1156 if (bitmap->storage.file)
1157 /* Only one copy, so nothing needed */
1160 for (i = 0; i < bitmap->storage.file_pages; i++)
1161 set_page_attr(bitmap, i,
1162 BITMAP_PAGE_NEEDWRITE);
1163 bitmap->allclean = 0;
1166 static void bitmap_count_page(struct bitmap_counts *bitmap,
1167 sector_t offset, int inc)
1169 sector_t chunk = offset >> bitmap->chunkshift;
1170 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1171 bitmap->bp[page].count += inc;
1172 bitmap_checkfree(bitmap, page);
1175 static void bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1177 sector_t chunk = offset >> bitmap->chunkshift;
1178 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1179 struct bitmap_page *bp = &bitmap->bp[page];
1185 static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
1186 sector_t offset, sector_t *blocks,
1190 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1194 void bitmap_daemon_work(struct mddev *mddev)
1196 struct bitmap *bitmap;
1198 unsigned long nextpage;
1200 struct bitmap_counts *counts;
1202 /* Use a mutex to guard daemon_work against
1205 mutex_lock(&mddev->bitmap_info.mutex);
1206 bitmap = mddev->bitmap;
1207 if (bitmap == NULL) {
1208 mutex_unlock(&mddev->bitmap_info.mutex);
1211 if (time_before(jiffies, bitmap->daemon_lastrun
1212 + mddev->bitmap_info.daemon_sleep))
1215 bitmap->daemon_lastrun = jiffies;
1216 if (bitmap->allclean) {
1217 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1220 bitmap->allclean = 1;
1222 /* Any file-page which is PENDING now needs to be written.
1223 * So set NEEDWRITE now, then after we make any last-minute changes
1226 for (j = 0; j < bitmap->storage.file_pages; j++)
1227 if (test_and_clear_page_attr(bitmap, j,
1228 BITMAP_PAGE_PENDING))
1229 set_page_attr(bitmap, j,
1230 BITMAP_PAGE_NEEDWRITE);
1232 if (bitmap->need_sync &&
1233 mddev->bitmap_info.external == 0) {
1234 /* Arrange for superblock update as well as
1237 bitmap->need_sync = 0;
1238 if (bitmap->storage.filemap) {
1239 sb = kmap_atomic(bitmap->storage.sb_page);
1240 sb->events_cleared =
1241 cpu_to_le64(bitmap->events_cleared);
1243 set_page_attr(bitmap, 0,
1244 BITMAP_PAGE_NEEDWRITE);
1247 /* Now look at the bitmap counters and if any are '2' or '1',
1248 * decrement and handle accordingly.
1250 counts = &bitmap->counts;
1251 spin_lock_irq(&counts->lock);
1253 for (j = 0; j < counts->chunks; j++) {
1254 bitmap_counter_t *bmc;
1255 sector_t block = (sector_t)j << counts->chunkshift;
1257 if (j == nextpage) {
1258 nextpage += PAGE_COUNTER_RATIO;
1259 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1260 j |= PAGE_COUNTER_MASK;
1263 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1265 bmc = bitmap_get_counter(counts,
1270 j |= PAGE_COUNTER_MASK;
1273 if (*bmc == 1 && !bitmap->need_sync) {
1274 /* We can clear the bit */
1276 bitmap_count_page(counts, block, -1);
1277 bitmap_file_clear_bit(bitmap, block);
1278 } else if (*bmc && *bmc <= 2) {
1280 bitmap_set_pending(counts, block);
1281 bitmap->allclean = 0;
1284 spin_unlock_irq(&counts->lock);
1286 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1287 * DIRTY pages need to be written by bitmap_unplug so it can wait
1289 * If we find any DIRTY page we stop there and let bitmap_unplug
1290 * handle all the rest. This is important in the case where
1291 * the first blocking holds the superblock and it has been updated.
1292 * We mustn't write any other blocks before the superblock.
1295 j < bitmap->storage.file_pages
1296 && !test_bit(BITMAP_STALE, &bitmap->flags);
1298 if (test_page_attr(bitmap, j,
1300 /* bitmap_unplug will handle the rest */
1302 if (test_and_clear_page_attr(bitmap, j,
1303 BITMAP_PAGE_NEEDWRITE)) {
1304 write_page(bitmap, bitmap->storage.filemap[j], 0);
1309 if (bitmap->allclean == 0)
1310 mddev->thread->timeout =
1311 mddev->bitmap_info.daemon_sleep;
1312 mutex_unlock(&mddev->bitmap_info.mutex);
1315 static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
1316 sector_t offset, sector_t *blocks,
1318 __releases(bitmap->lock)
1319 __acquires(bitmap->lock)
1321 /* If 'create', we might release the lock and reclaim it.
1322 * The lock must have been taken with interrupts enabled.
1323 * If !create, we don't release the lock.
1325 sector_t chunk = offset >> bitmap->chunkshift;
1326 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1327 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1331 err = bitmap_checkpage(bitmap, page, create);
1333 if (bitmap->bp[page].hijacked ||
1334 bitmap->bp[page].map == NULL)
1335 csize = ((sector_t)1) << (bitmap->chunkshift +
1336 PAGE_COUNTER_SHIFT - 1);
1338 csize = ((sector_t)1) << bitmap->chunkshift;
1339 *blocks = csize - (offset & (csize - 1));
1344 /* now locked ... */
1346 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1347 /* should we use the first or second counter field
1348 * of the hijacked pointer? */
1349 int hi = (pageoff > PAGE_COUNTER_MASK);
1350 return &((bitmap_counter_t *)
1351 &bitmap->bp[page].map)[hi];
1352 } else /* page is allocated */
1353 return (bitmap_counter_t *)
1354 &(bitmap->bp[page].map[pageoff]);
1357 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1364 atomic_inc(&bitmap->behind_writes);
1365 bw = atomic_read(&bitmap->behind_writes);
1366 if (bw > bitmap->behind_writes_used)
1367 bitmap->behind_writes_used = bw;
1369 pr_debug("inc write-behind count %d/%lu\n",
1370 bw, bitmap->mddev->bitmap_info.max_write_behind);
1375 bitmap_counter_t *bmc;
1377 spin_lock_irq(&bitmap->counts.lock);
1378 bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1380 spin_unlock_irq(&bitmap->counts.lock);
1384 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1385 DEFINE_WAIT(__wait);
1386 /* note that it is safe to do the prepare_to_wait
1387 * after the test as long as we do it before dropping
1390 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1391 TASK_UNINTERRUPTIBLE);
1392 spin_unlock_irq(&bitmap->counts.lock);
1394 finish_wait(&bitmap->overflow_wait, &__wait);
1400 bitmap_file_set_bit(bitmap, offset);
1401 bitmap_count_page(&bitmap->counts, offset, 1);
1409 spin_unlock_irq(&bitmap->counts.lock);
1412 if (sectors > blocks)
1419 EXPORT_SYMBOL(bitmap_startwrite);
1421 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1422 int success, int behind)
1427 if (atomic_dec_and_test(&bitmap->behind_writes))
1428 wake_up(&bitmap->behind_wait);
1429 pr_debug("dec write-behind count %d/%lu\n",
1430 atomic_read(&bitmap->behind_writes),
1431 bitmap->mddev->bitmap_info.max_write_behind);
1436 unsigned long flags;
1437 bitmap_counter_t *bmc;
1439 spin_lock_irqsave(&bitmap->counts.lock, flags);
1440 bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1442 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1446 if (success && !bitmap->mddev->degraded &&
1447 bitmap->events_cleared < bitmap->mddev->events) {
1448 bitmap->events_cleared = bitmap->mddev->events;
1449 bitmap->need_sync = 1;
1450 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1453 if (!success && !NEEDED(*bmc))
1454 *bmc |= NEEDED_MASK;
1456 if (COUNTER(*bmc) == COUNTER_MAX)
1457 wake_up(&bitmap->overflow_wait);
1461 bitmap_set_pending(&bitmap->counts, offset);
1462 bitmap->allclean = 0;
1464 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1466 if (sectors > blocks)
1472 EXPORT_SYMBOL(bitmap_endwrite);
1474 static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1477 bitmap_counter_t *bmc;
1479 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1481 return 1; /* always resync if no bitmap */
1483 spin_lock_irq(&bitmap->counts.lock);
1484 bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1490 else if (NEEDED(*bmc)) {
1492 if (!degraded) { /* don't set/clear bits if degraded */
1493 *bmc |= RESYNC_MASK;
1494 *bmc &= ~NEEDED_MASK;
1498 spin_unlock_irq(&bitmap->counts.lock);
1502 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1505 /* bitmap_start_sync must always report on multiples of whole
1506 * pages, otherwise resync (which is very PAGE_SIZE based) will
1508 * So call __bitmap_start_sync repeatedly (if needed) until
1509 * At least PAGE_SIZE>>9 blocks are covered.
1510 * Return the 'or' of the result.
1516 while (*blocks < (PAGE_SIZE>>9)) {
1517 rv |= __bitmap_start_sync(bitmap, offset,
1518 &blocks1, degraded);
1524 EXPORT_SYMBOL(bitmap_start_sync);
1526 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1528 bitmap_counter_t *bmc;
1529 unsigned long flags;
1531 if (bitmap == NULL) {
1535 spin_lock_irqsave(&bitmap->counts.lock, flags);
1536 bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1541 *bmc &= ~RESYNC_MASK;
1543 if (!NEEDED(*bmc) && aborted)
1544 *bmc |= NEEDED_MASK;
1547 bitmap_set_pending(&bitmap->counts, offset);
1548 bitmap->allclean = 0;
1553 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1555 EXPORT_SYMBOL(bitmap_end_sync);
1557 void bitmap_close_sync(struct bitmap *bitmap)
1559 /* Sync has finished, and any bitmap chunks that weren't synced
1560 * properly have been aborted. It remains to us to clear the
1561 * RESYNC bit wherever it is still on
1563 sector_t sector = 0;
1567 while (sector < bitmap->mddev->resync_max_sectors) {
1568 bitmap_end_sync(bitmap, sector, &blocks, 0);
1572 EXPORT_SYMBOL(bitmap_close_sync);
1574 void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
1582 bitmap->last_end_sync = jiffies;
1585 if (time_before(jiffies, (bitmap->last_end_sync
1586 + bitmap->mddev->bitmap_info.daemon_sleep)))
1588 wait_event(bitmap->mddev->recovery_wait,
1589 atomic_read(&bitmap->mddev->recovery_active) == 0);
1591 bitmap->mddev->curr_resync_completed = sector;
1592 set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1593 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1595 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1596 bitmap_end_sync(bitmap, s, &blocks, 0);
1599 bitmap->last_end_sync = jiffies;
1600 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1602 EXPORT_SYMBOL(bitmap_cond_end_sync);
1604 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1606 /* For each chunk covered by any of these sectors, set the
1607 * counter to 2 and possibly set resync_needed. They should all
1608 * be 0 at this point
1612 bitmap_counter_t *bmc;
1613 spin_lock_irq(&bitmap->counts.lock);
1614 bmc = bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1616 spin_unlock_irq(&bitmap->counts.lock);
1621 bitmap_count_page(&bitmap->counts, offset, 1);
1622 bitmap_set_pending(&bitmap->counts, offset);
1623 bitmap->allclean = 0;
1626 *bmc |= NEEDED_MASK;
1627 spin_unlock_irq(&bitmap->counts.lock);
1630 /* dirty the memory and file bits for bitmap chunks "s" to "e" */
1631 void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1633 unsigned long chunk;
1635 for (chunk = s; chunk <= e; chunk++) {
1636 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1637 bitmap_set_memory_bits(bitmap, sec, 1);
1638 bitmap_file_set_bit(bitmap, sec);
1639 if (sec < bitmap->mddev->recovery_cp)
1640 /* We are asserting that the array is dirty,
1641 * so move the recovery_cp address back so
1642 * that it is obvious that it is dirty
1644 bitmap->mddev->recovery_cp = sec;
1649 * flush out any pending updates
1651 void bitmap_flush(struct mddev *mddev)
1653 struct bitmap *bitmap = mddev->bitmap;
1656 if (!bitmap) /* there was no bitmap */
1659 /* run the daemon_work three time to ensure everything is flushed
1662 sleep = mddev->bitmap_info.daemon_sleep * 2;
1663 bitmap->daemon_lastrun -= sleep;
1664 bitmap_daemon_work(mddev);
1665 bitmap->daemon_lastrun -= sleep;
1666 bitmap_daemon_work(mddev);
1667 bitmap->daemon_lastrun -= sleep;
1668 bitmap_daemon_work(mddev);
1669 bitmap_update_sb(bitmap);
1673 * free memory that was allocated
1675 static void bitmap_free(struct bitmap *bitmap)
1677 unsigned long k, pages;
1678 struct bitmap_page *bp;
1680 if (!bitmap) /* there was no bitmap */
1683 if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
1684 bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
1685 md_cluster_stop(bitmap->mddev);
1687 /* Shouldn't be needed - but just in case.... */
1688 wait_event(bitmap->write_wait,
1689 atomic_read(&bitmap->pending_writes) == 0);
1691 /* release the bitmap file */
1692 bitmap_file_unmap(&bitmap->storage);
1694 bp = bitmap->counts.bp;
1695 pages = bitmap->counts.pages;
1697 /* free all allocated memory */
1699 if (bp) /* deallocate the page memory */
1700 for (k = 0; k < pages; k++)
1701 if (bp[k].map && !bp[k].hijacked)
1707 void bitmap_destroy(struct mddev *mddev)
1709 struct bitmap *bitmap = mddev->bitmap;
1711 if (!bitmap) /* there was no bitmap */
1714 mutex_lock(&mddev->bitmap_info.mutex);
1715 spin_lock(&mddev->lock);
1716 mddev->bitmap = NULL; /* disconnect from the md device */
1717 spin_unlock(&mddev->lock);
1718 mutex_unlock(&mddev->bitmap_info.mutex);
1720 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1722 if (bitmap->sysfs_can_clear)
1723 sysfs_put(bitmap->sysfs_can_clear);
1725 bitmap_free(bitmap);
1729 * initialize the bitmap structure
1730 * if this returns an error, bitmap_destroy must be called to do clean up
1732 struct bitmap *bitmap_create(struct mddev *mddev, int slot)
1734 struct bitmap *bitmap;
1735 sector_t blocks = mddev->resync_max_sectors;
1736 struct file *file = mddev->bitmap_info.file;
1738 struct kernfs_node *bm = NULL;
1740 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1742 BUG_ON(file && mddev->bitmap_info.offset);
1744 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1746 return ERR_PTR(-ENOMEM);
1748 spin_lock_init(&bitmap->counts.lock);
1749 atomic_set(&bitmap->pending_writes, 0);
1750 init_waitqueue_head(&bitmap->write_wait);
1751 init_waitqueue_head(&bitmap->overflow_wait);
1752 init_waitqueue_head(&bitmap->behind_wait);
1754 bitmap->mddev = mddev;
1755 bitmap->cluster_slot = slot;
1758 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
1760 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
1763 bitmap->sysfs_can_clear = NULL;
1765 bitmap->storage.file = file;
1768 /* As future accesses to this file will use bmap,
1769 * and bypass the page cache, we must sync the file
1774 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1775 if (!mddev->bitmap_info.external) {
1777 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1778 * instructing us to create a new on-disk bitmap instance.
1780 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1781 err = bitmap_new_disk_sb(bitmap);
1783 err = bitmap_read_sb(bitmap);
1786 if (mddev->bitmap_info.chunksize == 0 ||
1787 mddev->bitmap_info.daemon_sleep == 0)
1788 /* chunksize and time_base need to be
1795 bitmap->daemon_lastrun = jiffies;
1796 err = bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1800 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1801 bitmap->counts.pages, bmname(bitmap));
1803 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1809 bitmap_free(bitmap);
1810 return ERR_PTR(err);
1813 int bitmap_load(struct mddev *mddev)
1817 sector_t sector = 0;
1818 struct bitmap *bitmap = mddev->bitmap;
1823 /* Clear out old bitmap info first: Either there is none, or we
1824 * are resuming after someone else has possibly changed things,
1825 * so we should forget old cached info.
1826 * All chunks should be clean, but some might need_sync.
1828 while (sector < mddev->resync_max_sectors) {
1830 bitmap_start_sync(bitmap, sector, &blocks, 0);
1833 bitmap_close_sync(bitmap);
1835 if (mddev->degraded == 0
1836 || bitmap->events_cleared == mddev->events)
1837 /* no need to keep dirty bits to optimise a
1838 * re-add of a missing device */
1839 start = mddev->recovery_cp;
1841 mutex_lock(&mddev->bitmap_info.mutex);
1842 err = bitmap_init_from_disk(bitmap, start);
1843 mutex_unlock(&mddev->bitmap_info.mutex);
1847 clear_bit(BITMAP_STALE, &bitmap->flags);
1849 /* Kick recovery in case any bits were set */
1850 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1852 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1853 md_wakeup_thread(mddev->thread);
1855 bitmap_update_sb(bitmap);
1857 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1862 EXPORT_SYMBOL_GPL(bitmap_load);
1864 /* Loads the bitmap associated with slot and copies the resync information
1867 int bitmap_copy_from_slot(struct mddev *mddev, int slot,
1868 sector_t *low, sector_t *high, bool clear_bits)
1871 sector_t block, lo = 0, hi = 0;
1872 struct bitmap_counts *counts;
1873 struct bitmap *bitmap = bitmap_create(mddev, slot);
1876 return PTR_ERR(bitmap);
1878 rv = bitmap_read_sb(bitmap);
1882 rv = bitmap_init_from_disk(bitmap, 0);
1886 counts = &bitmap->counts;
1887 for (j = 0; j < counts->chunks; j++) {
1888 block = (sector_t)j << counts->chunkshift;
1889 if (bitmap_file_test_bit(bitmap, block)) {
1893 bitmap_file_clear_bit(bitmap, block);
1894 bitmap_set_memory_bits(mddev->bitmap, block, 1);
1895 bitmap_file_set_bit(mddev->bitmap, block);
1900 bitmap_update_sb(bitmap);
1901 /* Setting this for the ev_page should be enough.
1902 * And we do not require both write_all and PAGE_DIRT either
1904 for (i = 0; i < bitmap->storage.file_pages; i++)
1905 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
1906 bitmap_write_all(bitmap);
1907 bitmap_unplug(bitmap);
1912 bitmap_free(bitmap);
1915 EXPORT_SYMBOL_GPL(bitmap_copy_from_slot);
1918 void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
1920 unsigned long chunk_kb;
1921 struct bitmap_counts *counts;
1926 counts = &bitmap->counts;
1928 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
1929 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
1931 counts->pages - counts->missing_pages,
1933 (counts->pages - counts->missing_pages)
1934 << (PAGE_SHIFT - 10),
1935 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
1936 chunk_kb ? "KB" : "B");
1937 if (bitmap->storage.file) {
1938 seq_printf(seq, ", file: ");
1939 seq_path(seq, &bitmap->storage.file->f_path, " \t\n");
1942 seq_printf(seq, "\n");
1945 int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
1946 int chunksize, int init)
1948 /* If chunk_size is 0, choose an appropriate chunk size.
1949 * Then possibly allocate new storage space.
1950 * Then quiesce, copy bits, replace bitmap, and re-start
1952 * This function is called both to set up the initial bitmap
1953 * and to resize the bitmap while the array is active.
1954 * If this happens as a result of the array being resized,
1955 * chunksize will be zero, and we need to choose a suitable
1956 * chunksize, otherwise we use what we are given.
1958 struct bitmap_storage store;
1959 struct bitmap_counts old_counts;
1960 unsigned long chunks;
1962 sector_t old_blocks, new_blocks;
1966 struct bitmap_page *new_bp;
1968 if (chunksize == 0) {
1969 /* If there is enough space, leave the chunk size unchanged,
1970 * else increase by factor of two until there is enough space.
1973 long space = bitmap->mddev->bitmap_info.space;
1976 /* We don't know how much space there is, so limit
1977 * to current size - in sectors.
1979 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
1980 if (!bitmap->mddev->bitmap_info.external)
1981 bytes += sizeof(bitmap_super_t);
1982 space = DIV_ROUND_UP(bytes, 512);
1983 bitmap->mddev->bitmap_info.space = space;
1985 chunkshift = bitmap->counts.chunkshift;
1988 /* 'chunkshift' is shift from block size to chunk size */
1990 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
1991 bytes = DIV_ROUND_UP(chunks, 8);
1992 if (!bitmap->mddev->bitmap_info.external)
1993 bytes += sizeof(bitmap_super_t);
1994 } while (bytes > (space << 9));
1996 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
1998 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
1999 memset(&store, 0, sizeof(store));
2000 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2001 ret = bitmap_storage_alloc(&store, chunks,
2002 !bitmap->mddev->bitmap_info.external,
2003 bitmap->cluster_slot);
2007 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2009 new_bp = kzalloc(pages * sizeof(*new_bp), GFP_KERNEL);
2012 bitmap_file_unmap(&store);
2017 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2019 store.file = bitmap->storage.file;
2020 bitmap->storage.file = NULL;
2022 if (store.sb_page && bitmap->storage.sb_page)
2023 memcpy(page_address(store.sb_page),
2024 page_address(bitmap->storage.sb_page),
2025 sizeof(bitmap_super_t));
2026 bitmap_file_unmap(&bitmap->storage);
2027 bitmap->storage = store;
2029 old_counts = bitmap->counts;
2030 bitmap->counts.bp = new_bp;
2031 bitmap->counts.pages = pages;
2032 bitmap->counts.missing_pages = pages;
2033 bitmap->counts.chunkshift = chunkshift;
2034 bitmap->counts.chunks = chunks;
2035 bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift +
2036 BITMAP_BLOCK_SHIFT);
2038 blocks = min(old_counts.chunks << old_counts.chunkshift,
2039 chunks << chunkshift);
2041 spin_lock_irq(&bitmap->counts.lock);
2042 for (block = 0; block < blocks; ) {
2043 bitmap_counter_t *bmc_old, *bmc_new;
2046 bmc_old = bitmap_get_counter(&old_counts, block,
2048 set = bmc_old && NEEDED(*bmc_old);
2051 bmc_new = bitmap_get_counter(&bitmap->counts, block,
2053 if (*bmc_new == 0) {
2054 /* need to set on-disk bits too. */
2055 sector_t end = block + new_blocks;
2056 sector_t start = block >> chunkshift;
2057 start <<= chunkshift;
2058 while (start < end) {
2059 bitmap_file_set_bit(bitmap, block);
2060 start += 1 << chunkshift;
2063 bitmap_count_page(&bitmap->counts,
2065 bitmap_set_pending(&bitmap->counts,
2068 *bmc_new |= NEEDED_MASK;
2069 if (new_blocks < old_blocks)
2070 old_blocks = new_blocks;
2072 block += old_blocks;
2077 while (block < (chunks << chunkshift)) {
2078 bitmap_counter_t *bmc;
2079 bmc = bitmap_get_counter(&bitmap->counts, block,
2082 /* new space. It needs to be resynced, so
2083 * we set NEEDED_MASK.
2086 *bmc = NEEDED_MASK | 2;
2087 bitmap_count_page(&bitmap->counts,
2089 bitmap_set_pending(&bitmap->counts,
2093 block += new_blocks;
2095 for (i = 0; i < bitmap->storage.file_pages; i++)
2096 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
2098 spin_unlock_irq(&bitmap->counts.lock);
2101 bitmap_unplug(bitmap);
2102 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2108 EXPORT_SYMBOL_GPL(bitmap_resize);
2111 location_show(struct mddev *mddev, char *page)
2114 if (mddev->bitmap_info.file)
2115 len = sprintf(page, "file");
2116 else if (mddev->bitmap_info.offset)
2117 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
2119 len = sprintf(page, "none");
2120 len += sprintf(page+len, "\n");
2125 location_store(struct mddev *mddev, const char *buf, size_t len)
2129 if (!mddev->pers->quiesce)
2131 if (mddev->recovery || mddev->sync_thread)
2135 if (mddev->bitmap || mddev->bitmap_info.file ||
2136 mddev->bitmap_info.offset) {
2137 /* bitmap already configured. Only option is to clear it */
2138 if (strncmp(buf, "none", 4) != 0)
2141 mddev->pers->quiesce(mddev, 1);
2142 bitmap_destroy(mddev);
2143 mddev->pers->quiesce(mddev, 0);
2145 mddev->bitmap_info.offset = 0;
2146 if (mddev->bitmap_info.file) {
2147 struct file *f = mddev->bitmap_info.file;
2148 mddev->bitmap_info.file = NULL;
2152 /* No bitmap, OK to set a location */
2154 if (strncmp(buf, "none", 4) == 0)
2155 /* nothing to be done */;
2156 else if (strncmp(buf, "file:", 5) == 0) {
2157 /* Not supported yet */
2162 rv = kstrtoll(buf+1, 10, &offset);
2164 rv = kstrtoll(buf, 10, &offset);
2169 if (mddev->bitmap_info.external == 0 &&
2170 mddev->major_version == 0 &&
2171 offset != mddev->bitmap_info.default_offset)
2173 mddev->bitmap_info.offset = offset;
2175 struct bitmap *bitmap;
2176 mddev->pers->quiesce(mddev, 1);
2177 bitmap = bitmap_create(mddev, -1);
2179 rv = PTR_ERR(bitmap);
2181 mddev->bitmap = bitmap;
2182 rv = bitmap_load(mddev);
2184 bitmap_destroy(mddev);
2185 mddev->bitmap_info.offset = 0;
2188 mddev->pers->quiesce(mddev, 0);
2194 if (!mddev->external) {
2195 /* Ensure new bitmap info is stored in
2196 * metadata promptly.
2198 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2199 md_wakeup_thread(mddev->thread);
2204 static struct md_sysfs_entry bitmap_location =
2205 __ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2207 /* 'bitmap/space' is the space available at 'location' for the
2208 * bitmap. This allows the kernel to know when it is safe to
2209 * resize the bitmap to match a resized array.
2212 space_show(struct mddev *mddev, char *page)
2214 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2218 space_store(struct mddev *mddev, const char *buf, size_t len)
2220 unsigned long sectors;
2223 rv = kstrtoul(buf, 10, §ors);
2230 if (mddev->bitmap &&
2231 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2232 return -EFBIG; /* Bitmap is too big for this small space */
2234 /* could make sure it isn't too big, but that isn't really
2235 * needed - user-space should be careful.
2237 mddev->bitmap_info.space = sectors;
2241 static struct md_sysfs_entry bitmap_space =
2242 __ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2245 timeout_show(struct mddev *mddev, char *page)
2248 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2249 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2251 len = sprintf(page, "%lu", secs);
2253 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2254 len += sprintf(page+len, "\n");
2259 timeout_store(struct mddev *mddev, const char *buf, size_t len)
2261 /* timeout can be set at any time */
2262 unsigned long timeout;
2263 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2267 /* just to make sure we don't overflow... */
2268 if (timeout >= LONG_MAX / HZ)
2271 timeout = timeout * HZ / 10000;
2273 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2274 timeout = MAX_SCHEDULE_TIMEOUT-1;
2277 mddev->bitmap_info.daemon_sleep = timeout;
2278 if (mddev->thread) {
2279 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
2280 * the bitmap is all clean and we don't need to
2281 * adjust the timeout right now
2283 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2284 mddev->thread->timeout = timeout;
2285 md_wakeup_thread(mddev->thread);
2291 static struct md_sysfs_entry bitmap_timeout =
2292 __ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2295 backlog_show(struct mddev *mddev, char *page)
2297 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2301 backlog_store(struct mddev *mddev, const char *buf, size_t len)
2303 unsigned long backlog;
2304 int rv = kstrtoul(buf, 10, &backlog);
2307 if (backlog > COUNTER_MAX)
2309 mddev->bitmap_info.max_write_behind = backlog;
2313 static struct md_sysfs_entry bitmap_backlog =
2314 __ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2317 chunksize_show(struct mddev *mddev, char *page)
2319 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2323 chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2325 /* Can only be changed when no bitmap is active */
2327 unsigned long csize;
2330 rv = kstrtoul(buf, 10, &csize);
2334 !is_power_of_2(csize))
2336 mddev->bitmap_info.chunksize = csize;
2340 static struct md_sysfs_entry bitmap_chunksize =
2341 __ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2343 static ssize_t metadata_show(struct mddev *mddev, char *page)
2345 if (mddev_is_clustered(mddev))
2346 return sprintf(page, "clustered\n");
2347 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2348 ? "external" : "internal"));
2351 static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2353 if (mddev->bitmap ||
2354 mddev->bitmap_info.file ||
2355 mddev->bitmap_info.offset)
2357 if (strncmp(buf, "external", 8) == 0)
2358 mddev->bitmap_info.external = 1;
2359 else if ((strncmp(buf, "internal", 8) == 0) ||
2360 (strncmp(buf, "clustered", 9) == 0))
2361 mddev->bitmap_info.external = 0;
2367 static struct md_sysfs_entry bitmap_metadata =
2368 __ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2370 static ssize_t can_clear_show(struct mddev *mddev, char *page)
2373 spin_lock(&mddev->lock);
2375 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2378 len = sprintf(page, "\n");
2379 spin_unlock(&mddev->lock);
2383 static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2385 if (mddev->bitmap == NULL)
2387 if (strncmp(buf, "false", 5) == 0)
2388 mddev->bitmap->need_sync = 1;
2389 else if (strncmp(buf, "true", 4) == 0) {
2390 if (mddev->degraded)
2392 mddev->bitmap->need_sync = 0;
2398 static struct md_sysfs_entry bitmap_can_clear =
2399 __ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2402 behind_writes_used_show(struct mddev *mddev, char *page)
2405 spin_lock(&mddev->lock);
2406 if (mddev->bitmap == NULL)
2407 ret = sprintf(page, "0\n");
2409 ret = sprintf(page, "%lu\n",
2410 mddev->bitmap->behind_writes_used);
2411 spin_unlock(&mddev->lock);
2416 behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2419 mddev->bitmap->behind_writes_used = 0;
2423 static struct md_sysfs_entry max_backlog_used =
2424 __ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2425 behind_writes_used_show, behind_writes_used_reset);
2427 static struct attribute *md_bitmap_attrs[] = {
2428 &bitmap_location.attr,
2430 &bitmap_timeout.attr,
2431 &bitmap_backlog.attr,
2432 &bitmap_chunksize.attr,
2433 &bitmap_metadata.attr,
2434 &bitmap_can_clear.attr,
2435 &max_backlog_used.attr,
2438 struct attribute_group md_bitmap_group = {
2440 .attrs = md_bitmap_attrs,