md: rename some drivers/md/ files to have an "md-" prefix

Motivated by the desire to illiminate the imprecise nature of
DM-specific patches being unnecessarily sent to both the MD maintainer
and mailing-list.  Which is born out of the fact that DM files also
reside in drivers/md/

Now all MD-specific files in drivers/md/ start with either "raid" or
"md-" and the MAINTAINERS file has been updated accordingly.

Shaohua: don't change module name

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>

1 files changed, 0 insertions, 2591 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
deleted file mode 100644
index cae57b5be817..000000000000
--- a/drivers/md/bitmap.c
+++ /dev/null
@@ -1,2591 +0,0 @@
-/*
- * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
- *
- * bitmap_create  - sets up the bitmap structure
- * bitmap_destroy - destroys the bitmap structure
- *
- * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
- * - added disk storage for bitmap
- * - changes to allow various bitmap chunk sizes
- */
-
-/*
- * Still to do:
- *
- * flush after percent set rather than just time based. (maybe both).
- */
-
-#include <linux/blkdev.h>
-#include <linux/module.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/timer.h>
-#include <linux/sched.h>
-#include <linux/list.h>
-#include <linux/file.h>
-#include <linux/mount.h>
-#include <linux/buffer_head.h>
-#include <linux/seq_file.h>
-#include <trace/events/block.h>
-#include "md.h"
-#include "bitmap.h"
-
-static inline char *bmname(struct bitmap *bitmap)
-{
-	return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
-}
-
-/*
- * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
- *
- * 1) check to see if this page is allocated, if it's not then try to alloc
- * 2) if the alloc fails, set the page's hijacked flag so we'll use the
- *    page pointer directly as a counter
- *
- * if we find our page, we increment the page's refcount so that it stays
- * allocated while we're using it
- */
-static int bitmap_checkpage(struct bitmap_counts *bitmap,
-			    unsigned long page, int create, int no_hijack)
-__releases(bitmap->lock)
-__acquires(bitmap->lock)
-{
-	unsigned char *mappage;
-
-	if (page >= bitmap->pages) {
-		/* This can happen if bitmap_start_sync goes beyond
-		 * End-of-device while looking for a whole page.
-		 * It is harmless.
-		 */
-		return -EINVAL;
-	}
-
-	if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
-		return 0;
-
-	if (bitmap->bp[page].map) /* page is already allocated, just return */
-		return 0;
-
-	if (!create)
-		return -ENOENT;
-
-	/* this page has not been allocated yet */
-
-	spin_unlock_irq(&bitmap->lock);
-	/* It is possible that this is being called inside a
-	 * prepare_to_wait/finish_wait loop from raid5c:make_request().
-	 * In general it is not permitted to sleep in that context as it
-	 * can cause the loop to spin freely.
-	 * That doesn't apply here as we can only reach this point
-	 * once with any loop.
-	 * When this function completes, either bp[page].map or
-	 * bp[page].hijacked.  In either case, this function will
-	 * abort before getting to this point again.  So there is
-	 * no risk of a free-spin, and so it is safe to assert
-	 * that sleeping here is allowed.
-	 */
-	sched_annotate_sleep();
-	mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
-	spin_lock_irq(&bitmap->lock);
-
-	if (mappage == NULL) {
-		pr_debug("md/bitmap: map page allocation failed, hijacking\n");
-		/* We don't support hijack for cluster raid */
-		if (no_hijack)
-			return -ENOMEM;
-		/* failed - set the hijacked flag so that we can use the
-		 * pointer as a counter */
-		if (!bitmap->bp[page].map)
-			bitmap->bp[page].hijacked = 1;
-	} else if (bitmap->bp[page].map ||
-		   bitmap->bp[page].hijacked) {
-		/* somebody beat us to getting the page */
-		kfree(mappage);
-	} else {
-
-		/* no page was in place and we have one, so install it */
-
-		bitmap->bp[page].map = mappage;
-		bitmap->missing_pages--;
-	}
-	return 0;
-}
-
-/* if page is completely empty, put it back on the free list, or dealloc it */
-/* if page was hijacked, unmark the flag so it might get alloced next time */
-/* Note: lock should be held when calling this */
-static void bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
-{
-	char *ptr;
-
-	if (bitmap->bp[page].count) /* page is still busy */
-		return;
-
-	/* page is no longer in use, it can be released */
-
-	if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
-		bitmap->bp[page].hijacked = 0;
-		bitmap->bp[page].map = NULL;
-	} else {
-		/* normal case, free the page */
-		ptr = bitmap->bp[page].map;
-		bitmap->bp[page].map = NULL;
-		bitmap->missing_pages++;
-		kfree(ptr);
-	}
-}
-
-/*
- * bitmap file handling - read and write the bitmap file and its superblock
- */
-
-/*
- * basic page I/O operations
- */
-
-/* IO operations when bitmap is stored near all superblocks */
-static int read_sb_page(struct mddev *mddev, loff_t offset,
-			struct page *page,
-			unsigned long index, int size)
-{
-	/* choose a good rdev and read the page from there */
-
-	struct md_rdev *rdev;
-	sector_t target;
-
-	rdev_for_each(rdev, mddev) {
-		if (! test_bit(In_sync, &rdev->flags)
-		    || test_bit(Faulty, &rdev->flags)
-		    || test_bit(Bitmap_sync, &rdev->flags))
-			continue;
-
-		target = offset + index * (PAGE_SIZE/512);
-
-		if (sync_page_io(rdev, target,
-				 roundup(size, bdev_logical_block_size(rdev->bdev)),
-				 page, REQ_OP_READ, 0, true)) {
-			page->index = index;
-			return 0;
-		}
-	}
-	return -EIO;
-}
-
-static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
-{
-	/* Iterate the disks of an mddev, using rcu to protect access to the
-	 * linked list, and raising the refcount of devices we return to ensure
-	 * they don't disappear while in use.
-	 * As devices are only added or removed when raid_disk is < 0 and
-	 * nr_pending is 0 and In_sync is clear, the entries we return will
-	 * still be in the same position on the list when we re-enter
-	 * list_for_each_entry_continue_rcu.
-	 *
-	 * Note that if entered with 'rdev == NULL' to start at the
-	 * beginning, we temporarily assign 'rdev' to an address which
-	 * isn't really an rdev, but which can be used by
-	 * list_for_each_entry_continue_rcu() to find the first entry.
-	 */
-	rcu_read_lock();
-	if (rdev == NULL)
-		/* start at the beginning */
-		rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
-	else {
-		/* release the previous rdev and start from there. */
-		rdev_dec_pending(rdev, mddev);
-	}
-	list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
-		if (rdev->raid_disk >= 0 &&
-		    !test_bit(Faulty, &rdev->flags)) {
-			/* this is a usable devices */
-			atomic_inc(&rdev->nr_pending);
-			rcu_read_unlock();
-			return rdev;
-		}
-	}
-	rcu_read_unlock();
-	return NULL;
-}
-
-static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
-{
-	struct md_rdev *rdev;
-	struct block_device *bdev;
-	struct mddev *mddev = bitmap->mddev;
-	struct bitmap_storage *store = &bitmap->storage;
-
-restart:
-	rdev = NULL;
-	while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
-		int size = PAGE_SIZE;
-		loff_t offset = mddev->bitmap_info.offset;
-
-		bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
-
-		if (page->index == store->file_pages-1) {
-			int last_page_size = store->bytes & (PAGE_SIZE-1);
-			if (last_page_size == 0)
-				last_page_size = PAGE_SIZE;
-			size = roundup(last_page_size,
-				       bdev_logical_block_size(bdev));
-		}
-		/* Just make sure we aren't corrupting data or
-		 * metadata
-		 */
-		if (mddev->external) {
-			/* Bitmap could be anywhere. */
-			if (rdev->sb_start + offset + (page->index
-						       * (PAGE_SIZE/512))
-			    > rdev->data_offset
-			    &&
-			    rdev->sb_start + offset
-			    < (rdev->data_offset + mddev->dev_sectors
-			     + (PAGE_SIZE/512)))
-				goto bad_alignment;
-		} else if (offset < 0) {
-			/* DATA  BITMAP METADATA  */
-			if (offset
-			    + (long)(page->index * (PAGE_SIZE/512))
-			    + size/512 > 0)
-				/* bitmap runs in to metadata */
-				goto bad_alignment;
-			if (rdev->data_offset + mddev->dev_sectors
-			    > rdev->sb_start + offset)
-				/* data runs in to bitmap */
-				goto bad_alignment;
-		} else if (rdev->sb_start < rdev->data_offset) {
-			/* METADATA BITMAP DATA */
-			if (rdev->sb_start
-			    + offset
-			    + page->index*(PAGE_SIZE/512) + size/512
-			    > rdev->data_offset)
-				/* bitmap runs in to data */
-				goto bad_alignment;
-		} else {
-			/* DATA METADATA BITMAP - no problems */
-		}
-		md_super_write(mddev, rdev,
-			       rdev->sb_start + offset
-			       + page->index * (PAGE_SIZE/512),
-			       size,
-			       page);
-	}
-
-	if (wait && md_super_wait(mddev) < 0)
-		goto restart;
-	return 0;
-
- bad_alignment:
-	return -EINVAL;
-}
-
-static void bitmap_file_kick(struct bitmap *bitmap);
-/*
- * write out a page to a file
- */
-static void write_page(struct bitmap *bitmap, struct page *page, int wait)
-{
-	struct buffer_head *bh;
-
-	if (bitmap->storage.file == NULL) {
-		switch (write_sb_page(bitmap, page, wait)) {
-		case -EINVAL:
-			set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
-		}
-	} else {
-
-		bh = page_buffers(page);
-
-		while (bh && bh->b_blocknr) {
-			atomic_inc(&bitmap->pending_writes);
-			set_buffer_locked(bh);
-			set_buffer_mapped(bh);
-			submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
-			bh = bh->b_this_page;
-		}
-
-		if (wait)
-			wait_event(bitmap->write_wait,
-				   atomic_read(&bitmap->pending_writes)==0);
-	}
-	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
-		bitmap_file_kick(bitmap);
-}
-
-static void end_bitmap_write(struct buffer_head *bh, int uptodate)
-{
-	struct bitmap *bitmap = bh->b_private;
-
-	if (!uptodate)
-		set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
-	if (atomic_dec_and_test(&bitmap->pending_writes))
-		wake_up(&bitmap->write_wait);
-}
-
-/* copied from buffer.c */
-static void
-__clear_page_buffers(struct page *page)
-{
-	ClearPagePrivate(page);
-	set_page_private(page, 0);
-	put_page(page);
-}
-static void free_buffers(struct page *page)
-{
-	struct buffer_head *bh;
-
-	if (!PagePrivate(page))
-		return;
-
-	bh = page_buffers(page);
-	while (bh) {
-		struct buffer_head *next = bh->b_this_page;
-		free_buffer_head(bh);
-		bh = next;
-	}
-	__clear_page_buffers(page);
-	put_page(page);
-}
-
-/* read a page from a file.
- * We both read the page, and attach buffers to the page to record the
- * address of each block (using bmap).  These addresses will be used
- * to write the block later, completely bypassing the filesystem.
- * This usage is similar to how swap files are handled, and allows us
- * to write to a file with no concerns of memory allocation failing.
- */
-static int read_page(struct file *file, unsigned long index,
-		     struct bitmap *bitmap,
-		     unsigned long count,
-		     struct page *page)
-{
-	int ret = 0;
-	struct inode *inode = file_inode(file);
-	struct buffer_head *bh;
-	sector_t block;
-
-	pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
-		 (unsigned long long)index << PAGE_SHIFT);
-
-	bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
-	if (!bh) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	attach_page_buffers(page, bh);
-	block = index << (PAGE_SHIFT - inode->i_blkbits);
-	while (bh) {
-		if (count == 0)
-			bh->b_blocknr = 0;
-		else {
-			bh->b_blocknr = bmap(inode, block);
-			if (bh->b_blocknr == 0) {
-				/* Cannot use this file! */
-				ret = -EINVAL;
-				goto out;
-			}
-			bh->b_bdev = inode->i_sb->s_bdev;
-			if (count < (1<<inode->i_blkbits))
-				count = 0;
-			else
-				count -= (1<<inode->i_blkbits);
-
-			bh->b_end_io = end_bitmap_write;
-			bh->b_private = bitmap;
-			atomic_inc(&bitmap->pending_writes);
-			set_buffer_locked(bh);
-			set_buffer_mapped(bh);
-			submit_bh(REQ_OP_READ, 0, bh);
-		}
-		block++;
-		bh = bh->b_this_page;
-	}
-	page->index = index;
-
-	wait_event(bitmap->write_wait,
-		   atomic_read(&bitmap->pending_writes)==0);
-	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
-		ret = -EIO;
-out:
-	if (ret)
-		pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
-		       (int)PAGE_SIZE,
-		       (unsigned long long)index << PAGE_SHIFT,
-		       ret);
-	return ret;
-}
-
-/*
- * bitmap file superblock operations
- */
-
-/*
- * bitmap_wait_writes() should be called before writing any bitmap
- * blocks, to ensure previous writes, particularly from
- * bitmap_daemon_work(), have completed.
- */
-static void bitmap_wait_writes(struct bitmap *bitmap)
-{
-	if (bitmap->storage.file)
-		wait_event(bitmap->write_wait,
-			   atomic_read(&bitmap->pending_writes)==0);
-	else
-		/* Note that we ignore the return value.  The writes
-		 * might have failed, but that would just mean that
-		 * some bits which should be cleared haven't been,
-		 * which is safe.  The relevant bitmap blocks will
-		 * probably get written again, but there is no great
-		 * loss if they aren't.
-		 */
-		md_super_wait(bitmap->mddev);
-}
-
-
-/* update the event counter and sync the superblock to disk */
-void bitmap_update_sb(struct bitmap *bitmap)
-{
-	bitmap_super_t *sb;
-
-	if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
-		return;
-	if (bitmap->mddev->bitmap_info.external)
-		return;
-	if (!bitmap->storage.sb_page) /* no superblock */
-		return;
-	sb = kmap_atomic(bitmap->storage.sb_page);
-	sb->events = cpu_to_le64(bitmap->mddev->events);
-	if (bitmap->mddev->events < bitmap->events_cleared)
-		/* rocking back to read-only */
-		bitmap->events_cleared = bitmap->mddev->events;
-	sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
-	sb->state = cpu_to_le32(bitmap->flags);
-	/* Just in case these have been changed via sysfs: */
-	sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
-	sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
-	/* This might have been changed by a reshape */
-	sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
-	sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
-	sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
-	sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
-					   bitmap_info.space);
-	kunmap_atomic(sb);
-	write_page(bitmap, bitmap->storage.sb_page, 1);
-}
-EXPORT_SYMBOL(bitmap_update_sb);
-
-/* print out the bitmap file superblock */
-void bitmap_print_sb(struct bitmap *bitmap)
-{
-	bitmap_super_t *sb;
-
-	if (!bitmap || !bitmap->storage.sb_page)
-		return;
-	sb = kmap_atomic(bitmap->storage.sb_page);
-	pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
-	pr_debug("         magic: %08x\n", le32_to_cpu(sb->magic));
-	pr_debug("       version: %d\n", le32_to_cpu(sb->version));
-	pr_debug("          uuid: %08x.%08x.%08x.%08x\n",
-		 le32_to_cpu(*(__u32 *)(sb->uuid+0)),
-		 le32_to_cpu(*(__u32 *)(sb->uuid+4)),
-		 le32_to_cpu(*(__u32 *)(sb->uuid+8)),
-		 le32_to_cpu(*(__u32 *)(sb->uuid+12)));
-	pr_debug("        events: %llu\n",
-		 (unsigned long long) le64_to_cpu(sb->events));
-	pr_debug("events cleared: %llu\n",
-		 (unsigned long long) le64_to_cpu(sb->events_cleared));
-	pr_debug("         state: %08x\n", le32_to_cpu(sb->state));
-	pr_debug("     chunksize: %d B\n", le32_to_cpu(sb->chunksize));
-	pr_debug("  daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
-	pr_debug("     sync size: %llu KB\n",
-		 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
-	pr_debug("max write behind: %d\n", le32_to_cpu(sb->write_behind));
-	kunmap_atomic(sb);
-}
-
-/*
- * bitmap_new_disk_sb
- * @bitmap
- *
- * This function is somewhat the reverse of bitmap_read_sb.  bitmap_read_sb
- * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
- * This function verifies 'bitmap_info' and populates the on-disk bitmap
- * structure, which is to be written to disk.
- *
- * Returns: 0 on success, -Exxx on error
- */
-static int bitmap_new_disk_sb(struct bitmap *bitmap)
-{
-	bitmap_super_t *sb;
-	unsigned long chunksize, daemon_sleep, write_behind;
-
-	bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
-	if (bitmap->storage.sb_page == NULL)
-		return -ENOMEM;
-	bitmap->storage.sb_page->index = 0;
-
-	sb = kmap_atomic(bitmap->storage.sb_page);
-
-	sb->magic = cpu_to_le32(BITMAP_MAGIC);
-	sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
-
-	chunksize = bitmap->mddev->bitmap_info.chunksize;
-	BUG_ON(!chunksize);
-	if (!is_power_of_2(chunksize)) {
-		kunmap_atomic(sb);
-		pr_warn("bitmap chunksize not a power of 2\n");
-		return -EINVAL;
-	}
-	sb->chunksize = cpu_to_le32(chunksize);
-
-	daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
-	if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
-		pr_debug("Choosing daemon_sleep default (5 sec)\n");
-		daemon_sleep = 5 * HZ;
-	}
-	sb->daemon_sleep = cpu_to_le32(daemon_sleep);
-	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
-
-	/*
-	 * FIXME: write_behind for RAID1.  If not specified, what
-	 * is a good choice?  We choose COUNTER_MAX / 2 arbitrarily.
-	 */
-	write_behind = bitmap->mddev->bitmap_info.max_write_behind;
-	if (write_behind > COUNTER_MAX)
-		write_behind = COUNTER_MAX / 2;
-	sb->write_behind = cpu_to_le32(write_behind);
-	bitmap->mddev->bitmap_info.max_write_behind = write_behind;
-
-	/* keep the array size field of the bitmap superblock up to date */
-	sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
-
-	memcpy(sb->uuid, bitmap->mddev->uuid, 16);
-
-	set_bit(BITMAP_STALE, &bitmap->flags);
-	sb->state = cpu_to_le32(bitmap->flags);
-	bitmap->events_cleared = bitmap->mddev->events;
-	sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
-	bitmap->mddev->bitmap_info.nodes = 0;
-
-	kunmap_atomic(sb);
-
-	return 0;
-}
-
-/* read the superblock from the bitmap file and initialize some bitmap fields */
-static int bitmap_read_sb(struct bitmap *bitmap)
-{
-	char *reason = NULL;
-	bitmap_super_t *sb;
-	unsigned long chunksize, daemon_sleep, write_behind;
-	unsigned long long events;
-	int nodes = 0;
-	unsigned long sectors_reserved = 0;
-	int err = -EINVAL;
-	struct page *sb_page;
-	loff_t offset = bitmap->mddev->bitmap_info.offset;
-
-	if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
-		chunksize = 128 * 1024 * 1024;
-		daemon_sleep = 5 * HZ;
-		write_behind = 0;
-		set_bit(BITMAP_STALE, &bitmap->flags);
-		err = 0;
-		goto out_no_sb;
-	}
-	/* page 0 is the superblock, read it... */
-	sb_page = alloc_page(GFP_KERNEL);
-	if (!sb_page)
-		return -ENOMEM;
-	bitmap->storage.sb_page = sb_page;
-
-re_read:
-	/* If cluster_slot is set, the cluster is setup */
-	if (bitmap->cluster_slot >= 0) {
-		sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
-
-		sector_div(bm_blocks,
-			   bitmap->mddev->bitmap_info.chunksize >> 9);
-		/* bits to bytes */
-		bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
-		/* to 4k blocks */
-		bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
-		offset = bitmap->mddev->bitmap_info.offset + (bitmap->cluster_slot * (bm_blocks << 3));
-		pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
-			bitmap->cluster_slot, offset);
-	}
-
-	if (bitmap->storage.file) {
-		loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
-		int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
-
-		err = read_page(bitmap->storage.file, 0,
-				bitmap, bytes, sb_page);
-	} else {
-		err = read_sb_page(bitmap->mddev,
-				   offset,
-				   sb_page,
-				   0, sizeof(bitmap_super_t));
-	}
-	if (err)
-		return err;
-
-	err = -EINVAL;
-	sb = kmap_atomic(sb_page);
-
-	chunksize = le32_to_cpu(sb->chunksize);
-	daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
-	write_behind = le32_to_cpu(sb->write_behind);
-	sectors_reserved = le32_to_cpu(sb->sectors_reserved);
-	/* Setup nodes/clustername only if bitmap version is
-	 * cluster-compatible
-	 */
-	if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
-		nodes = le32_to_cpu(sb->nodes);
-		strlcpy(bitmap->mddev->bitmap_info.cluster_name,
-				sb->cluster_name, 64);
-	}
-
-	/* verify that the bitmap-specific fields are valid */
-	if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
-		reason = "bad magic";
-	else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
-		 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
-		reason = "unrecognized superblock version";
-	else if (chunksize < 512)
-		reason = "bitmap chunksize too small";
-	else if (!is_power_of_2(chunksize))
-		reason = "bitmap chunksize not a power of 2";
-	else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
-		reason = "daemon sleep period out of range";
-	else if (write_behind > COUNTER_MAX)
-		reason = "write-behind limit out of range (0 - 16383)";
-	if (reason) {
-		pr_warn("%s: invalid bitmap file superblock: %s\n",
-			bmname(bitmap), reason);
-		goto out;
-	}
-
-	/* keep the array size field of the bitmap superblock up to date */
-	sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
-
-	if (bitmap->mddev->persistent) {
-		/*
-		 * We have a persistent array superblock, so compare the
-		 * bitmap's UUID and event counter to the mddev's
-		 */
-		if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
-			pr_warn("%s: bitmap superblock UUID mismatch\n",
-				bmname(bitmap));
-			goto out;
-		}
-		events = le64_to_cpu(sb->events);
-		if (!nodes && (events < bitmap->mddev->events)) {
-			pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
-				bmname(bitmap), events,
-				(unsigned long long) bitmap->mddev->events);
-			set_bit(BITMAP_STALE, &bitmap->flags);
-		}
-	}
-
-	/* assign fields using values from superblock */
-	bitmap->flags |= le32_to_cpu(sb->state);
-	if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
-		set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
-	bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
-	strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
-	err = 0;
-
-out:
-	kunmap_atomic(sb);
-	/* Assigning chunksize is required for "re_read" */
-	bitmap->mddev->bitmap_info.chunksize = chunksize;
-	if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
-		err = md_setup_cluster(bitmap->mddev, nodes);
-		if (err) {
-			pr_warn("%s: Could not setup cluster service (%d)\n",
-				bmname(bitmap), err);
-			goto out_no_sb;
-		}
-		bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
-		goto re_read;
-	}
-
-
-out_no_sb:
-	if (test_bit(BITMAP_STALE, &bitmap->flags))
-		bitmap->events_cleared = bitmap->mddev->events;
-	bitmap->mddev->bitmap_info.chunksize = chunksize;
-	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
-	bitmap->mddev->bitmap_info.max_write_behind = write_behind;
-	bitmap->mddev->bitmap_info.nodes = nodes;
-	if (bitmap->mddev->bitmap_info.space == 0 ||
-	    bitmap->mddev->bitmap_info.space > sectors_reserved)
-		bitmap->mddev->bitmap_info.space = sectors_reserved;
-	if (err) {
-		bitmap_print_sb(bitmap);
-		if (bitmap->cluster_slot < 0)
-			md_cluster_stop(bitmap->mddev);
-	}
-	return err;
-}
-
-/*
- * general bitmap file operations
- */
-
-/*
- * on-disk bitmap:
- *
- * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
- * file a page at a time. There's a superblock at the start of the file.
- */
-/* calculate the index of the page that contains this bit */
-static inline unsigned long file_page_index(struct bitmap_storage *store,
-					    unsigned long chunk)
-{
-	if (store->sb_page)
-		chunk += sizeof(bitmap_super_t) << 3;
-	return chunk >> PAGE_BIT_SHIFT;
-}
-
-/* calculate the (bit) offset of this bit within a page */
-static inline unsigned long file_page_offset(struct bitmap_storage *store,
-					     unsigned long chunk)
-{
-	if (store->sb_page)
-		chunk += sizeof(bitmap_super_t) << 3;
-	return chunk & (PAGE_BITS - 1);
-}
-
-/*
- * return a pointer to the page in the filemap that contains the given bit
- *
- */
-static inline struct page *filemap_get_page(struct bitmap_storage *store,
-					    unsigned long chunk)
-{
-	if (file_page_index(store, chunk) >= store->file_pages)
-		return NULL;
-	return store->filemap[file_page_index(store, chunk)];
-}
-
-static int bitmap_storage_alloc(struct bitmap_storage *store,
-				unsigned long chunks, int with_super,
-				int slot_number)
-{
-	int pnum, offset = 0;
-	unsigned long num_pages;
-	unsigned long bytes;
-
-	bytes = DIV_ROUND_UP(chunks, 8);
-	if (with_super)
-		bytes += sizeof(bitmap_super_t);
-
-	num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
-	offset = slot_number * num_pages;
-
-	store->filemap = kmalloc(sizeof(struct page *)
-				 * num_pages, GFP_KERNEL);
-	if (!store->filemap)
-		return -ENOMEM;
-
-	if (with_super && !store->sb_page) {
-		store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
-		if (store->sb_page == NULL)
-			return -ENOMEM;
-	}
-
-	pnum = 0;
-	if (store->sb_page) {
-		store->filemap[0] = store->sb_page;
-		pnum = 1;
-		store->sb_page->index = offset;
-	}
-
-	for ( ; pnum < num_pages; pnum++) {
-		store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
-		if (!store->filemap[pnum]) {
-			store->file_pages = pnum;
-			return -ENOMEM;
-		}
-		store->filemap[pnum]->index = pnum + offset;
-	}
-	store->file_pages = pnum;
-
-	/* We need 4 bits per page, rounded up to a multiple
-	 * of sizeof(unsigned long) */
-	store->filemap_attr = kzalloc(
-		roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
-		GFP_KERNEL);
-	if (!store->filemap_attr)
-		return -ENOMEM;
-
-	store->bytes = bytes;
-
-	return 0;
-}
-
-static void bitmap_file_unmap(struct bitmap_storage *store)
-{
-	struct page **map, *sb_page;
-	int pages;
-	struct file *file;
-
-	file = store->file;
-	map = store->filemap;
-	pages = store->file_pages;
-	sb_page = store->sb_page;
-
-	while (pages--)
-		if (map[pages] != sb_page) /* 0 is sb_page, release it below */
-			free_buffers(map[pages]);
-	kfree(map);
-	kfree(store->filemap_attr);
-
-	if (sb_page)
-		free_buffers(sb_page);
-
-	if (file) {
-		struct inode *inode = file_inode(file);
-		invalidate_mapping_pages(inode->i_mapping, 0, -1);
-		fput(file);
-	}
-}
-
-/*
- * bitmap_file_kick - if an error occurs while manipulating the bitmap file
- * then it is no longer reliable, so we stop using it and we mark the file
- * as failed in the superblock
- */
-static void bitmap_file_kick(struct bitmap *bitmap)
-{
-	char *path, *ptr = NULL;
-
-	if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
-		bitmap_update_sb(bitmap);
-
-		if (bitmap->storage.file) {
-			path = kmalloc(PAGE_SIZE, GFP_KERNEL);
-			if (path)
-				ptr = file_path(bitmap->storage.file,
-					     path, PAGE_SIZE);
-
-			pr_warn("%s: kicking failed bitmap file %s from array!\n",
-				bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
-
-			kfree(path);
-		} else
-			pr_warn("%s: disabling internal bitmap due to errors\n",
-				bmname(bitmap));
-	}
-}
-
-enum bitmap_page_attr {
-	BITMAP_PAGE_DIRTY = 0,     /* there are set bits that need to be synced */
-	BITMAP_PAGE_PENDING = 1,   /* there are bits that are being cleaned.
-				    * i.e. counter is 1 or 2. */
-	BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
-};
-
-static inline void set_page_attr(struct bitmap *bitmap, int pnum,
-				 enum bitmap_page_attr attr)
-{
-	set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
-}
-
-static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
-				   enum bitmap_page_attr attr)
-{
-	clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
-}
-
-static inline int test_page_attr(struct bitmap *bitmap, int pnum,
-				 enum bitmap_page_attr attr)
-{
-	return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
-}
-
-static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
-					   enum bitmap_page_attr attr)
-{
-	return test_and_clear_bit((pnum<<2) + attr,
-				  bitmap->storage.filemap_attr);
-}
-/*
- * bitmap_file_set_bit -- called before performing a write to the md device
- * to set (and eventually sync) a particular bit in the bitmap file
- *
- * we set the bit immediately, then we record the page number so that
- * when an unplug occurs, we can flush the dirty pages out to disk
- */
-static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
-{
-	unsigned long bit;
-	struct page *page;
-	void *kaddr;
-	unsigned long chunk = block >> bitmap->counts.chunkshift;
-	struct bitmap_storage *store = &bitmap->storage;
-	unsigned long node_offset = 0;
-
-	if (mddev_is_clustered(bitmap->mddev))
-		node_offset = bitmap->cluster_slot * store->file_pages;
-
-	page = filemap_get_page(&bitmap->storage, chunk);
-	if (!page)
-		return;
-	bit = file_page_offset(&bitmap->storage, chunk);
-
-	/* set the bit */
-	kaddr = kmap_atomic(page);
-	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
-		set_bit(bit, kaddr);
-	else
-		set_bit_le(bit, kaddr);
-	kunmap_atomic(kaddr);
-	pr_debug("set file bit %lu page %lu\n", bit, page->index);
-	/* record page number so it gets flushed to disk when unplug occurs */
-	set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_DIRTY);
-}
-
-static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
-{
-	unsigned long bit;
-	struct page *page;
-	void *paddr;
-	unsigned long chunk = block >> bitmap->counts.chunkshift;
-	struct bitmap_storage *store = &bitmap->storage;
-	unsigned long node_offset = 0;
-
-	if (mddev_is_clustered(bitmap->mddev))
-		node_offset = bitmap->cluster_slot * store->file_pages;
-
-	page = filemap_get_page(&bitmap->storage, chunk);
-	if (!page)
-		return;
-	bit = file_page_offset(&bitmap->storage, chunk);
-	paddr = kmap_atomic(page);
-	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
-		clear_bit(bit, paddr);
-	else
-		clear_bit_le(bit, paddr);
-	kunmap_atomic(paddr);
-	if (!test_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
-		set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_PENDING);
-		bitmap->allclean = 0;
-	}
-}
-
-static int bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
-{
-	unsigned long bit;
-	struct page *page;
-	void *paddr;
-	unsigned long chunk = block >> bitmap->counts.chunkshift;
-	int set = 0;
-
-	page = filemap_get_page(&bitmap->storage, chunk);
-	if (!page)
-		return -EINVAL;
-	bit = file_page_offset(&bitmap->storage, chunk);
-	paddr = kmap_atomic(page);
-	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
-		set = test_bit(bit, paddr);
-	else
-		set = test_bit_le(bit, paddr);
-	kunmap_atomic(paddr);
-	return set;
-}
-
-
-/* this gets called when the md device is ready to unplug its underlying
- * (slave) device queues -- before we let any writes go down, we need to
- * sync the dirty pages of the bitmap file to disk */
-void bitmap_unplug(struct bitmap *bitmap)
-{
-	unsigned long i;
-	int dirty, need_write;
-	int writing = 0;
-
-	if (!bitmap || !bitmap->storage.filemap ||
-	    test_bit(BITMAP_STALE, &bitmap->flags))
-		return;
-
-	/* look at each page to see if there are any set bits that need to be
-	 * flushed out to disk */
-	for (i = 0; i < bitmap->storage.file_pages; i++) {
-		if (!bitmap->storage.filemap)
-			return;
-		dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
-		need_write = test_and_clear_page_attr(bitmap, i,
-						      BITMAP_PAGE_NEEDWRITE);
-		if (dirty || need_write) {
-			if (!writing) {
-				bitmap_wait_writes(bitmap);
-				if (bitmap->mddev->queue)
-					blk_add_trace_msg(bitmap->mddev->queue,
-							  "md bitmap_unplug");
-			}
-			clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
-			write_page(bitmap, bitmap->storage.filemap[i], 0);
-			writing = 1;
-		}
-	}
-	if (writing)
-		bitmap_wait_writes(bitmap);
-
-	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
-		bitmap_file_kick(bitmap);
-}
-EXPORT_SYMBOL(bitmap_unplug);
-
-static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
-/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
- * the in-memory bitmap from the on-disk bitmap -- also, sets up the
- * memory mapping of the bitmap file
- * Special cases:
- *   if there's no bitmap file, or if the bitmap file had been
- *   previously kicked from the array, we mark all the bits as
- *   1's in order to cause a full resync.
- *
- * We ignore all bits for sectors that end earlier than 'start'.
- * This is used when reading an out-of-date bitmap...
- */
-static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
-{
-	unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
-	struct page *page = NULL;
-	unsigned long bit_cnt = 0;
-	struct file *file;
-	unsigned long offset;
-	int outofdate;
-	int ret = -ENOSPC;
-	void *paddr;
-	struct bitmap_storage *store = &bitmap->storage;
-
-	chunks = bitmap->counts.chunks;
-	file = store->file;
-
-	if (!file && !bitmap->mddev->bitmap_info.offset) {
-		/* No permanent bitmap - fill with '1s'. */
-		store->filemap = NULL;
-		store->file_pages = 0;
-		for (i = 0; i < chunks ; i++) {
-			/* if the disk bit is set, set the memory bit */
-			int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
-				      >= start);
-			bitmap_set_memory_bits(bitmap,
-					       (sector_t)i << bitmap->counts.chunkshift,
-					       needed);
-		}
-		return 0;
-	}
-
-	outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
-	if (outofdate)
-		pr_warn("%s: bitmap file is out of date, doing full recovery\n", bmname(bitmap));
-
-	if (file && i_size_read(file->f_mapping->host) < store->bytes) {
-		pr_warn("%s: bitmap file too short %lu < %lu\n",
-			bmname(bitmap),
-			(unsigned long) i_size_read(file->f_mapping->host),
-			store->bytes);
-		goto err;
-	}
-
-	oldindex = ~0L;
-	offset = 0;
-	if (!bitmap->mddev->bitmap_info.external)
-		offset = sizeof(bitmap_super_t);
-
-	if (mddev_is_clustered(bitmap->mddev))
-		node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
-
-	for (i = 0; i < chunks; i++) {
-		int b;
-		index = file_page_index(&bitmap->storage, i);
-		bit = file_page_offset(&bitmap->storage, i);
-		if (index != oldindex) { /* this is a new page, read it in */
-			int count;
-			/* unmap the old page, we're done with it */
-			if (index == store->file_pages-1)
-				count = store->bytes - index * PAGE_SIZE;
-			else
-				count = PAGE_SIZE;
-			page = store->filemap[index];
-			if (file)
-				ret = read_page(file, index, bitmap,
-						count, page);
-			else
-				ret = read_sb_page(
-					bitmap->mddev,
-					bitmap->mddev->bitmap_info.offset,
-					page,
-					index + node_offset, count);
-
-			if (ret)
-				goto err;
-
-			oldindex = index;
-
-			if (outofdate) {
-				/*
-				 * if bitmap is out of date, dirty the
-				 * whole page and write it out
-				 */
-				paddr = kmap_atomic(page);
-				memset(paddr + offset, 0xff,
-				       PAGE_SIZE - offset);
-				kunmap_atomic(paddr);
-				write_page(bitmap, page, 1);
-
-				ret = -EIO;
-				if (test_bit(BITMAP_WRITE_ERROR,
-					     &bitmap->flags))
-					goto err;
-			}
-		}
-		paddr = kmap_atomic(page);
-		if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
-			b = test_bit(bit, paddr);
-		else
-			b = test_bit_le(bit, paddr);
-		kunmap_atomic(paddr);
-		if (b) {
-			/* if the disk bit is set, set the memory bit */
-			int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
-				      >= start);
-			bitmap_set_memory_bits(bitmap,
-					       (sector_t)i << bitmap->counts.chunkshift,
-					       needed);
-			bit_cnt++;
-		}
-		offset = 0;
-	}
-
-	pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
-		 bmname(bitmap), store->file_pages,
-		 bit_cnt, chunks);
-
-	return 0;
-
- err:
-	pr_warn("%s: bitmap initialisation failed: %d\n",
-		bmname(bitmap), ret);
-	return ret;
-}
-
-void bitmap_write_all(struct bitmap *bitmap)
-{
-	/* We don't actually write all bitmap blocks here,
-	 * just flag them as needing to be written
-	 */
-	int i;
-
-	if (!bitmap || !bitmap->storage.filemap)
-		return;
-	if (bitmap->storage.file)
-		/* Only one copy, so nothing needed */
-		return;
-
-	for (i = 0; i < bitmap->storage.file_pages; i++)
-		set_page_attr(bitmap, i,
-			      BITMAP_PAGE_NEEDWRITE);
-	bitmap->allclean = 0;
-}
-
-static void bitmap_count_page(struct bitmap_counts *bitmap,
-			      sector_t offset, int inc)
-{
-	sector_t chunk = offset >> bitmap->chunkshift;
-	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
-	bitmap->bp[page].count += inc;
-	bitmap_checkfree(bitmap, page);
-}
-
-static void bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
-{
-	sector_t chunk = offset >> bitmap->chunkshift;
-	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
-	struct bitmap_page *bp = &bitmap->bp[page];
-
-	if (!bp->pending)
-		bp->pending = 1;
-}
-
-static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
-					    sector_t offset, sector_t *blocks,
-					    int create);
-
-/*
- * bitmap daemon -- periodically wakes up to clean bits and flush pages
- *			out to disk
- */
-
-void bitmap_daemon_work(struct mddev *mddev)
-{
-	struct bitmap *bitmap;
-	unsigned long j;
-	unsigned long nextpage;
-	sector_t blocks;
-	struct bitmap_counts *counts;
-
-	/* Use a mutex to guard daemon_work against
-	 * bitmap_destroy.
-	 */
-	mutex_lock(&mddev->bitmap_info.mutex);
-	bitmap = mddev->bitmap;
-	if (bitmap == NULL) {
-		mutex_unlock(&mddev->bitmap_info.mutex);
-		return;
-	}
-	if (time_before(jiffies, bitmap->daemon_lastrun
-			+ mddev->bitmap_info.daemon_sleep))
-		goto done;
-
-	bitmap->daemon_lastrun = jiffies;
-	if (bitmap->allclean) {
-		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
-		goto done;
-	}
-	bitmap->allclean = 1;
-
-	if (bitmap->mddev->queue)
-		blk_add_trace_msg(bitmap->mddev->queue,
-				  "md bitmap_daemon_work");
-
-	/* Any file-page which is PENDING now needs to be written.
-	 * So set NEEDWRITE now, then after we make any last-minute changes
-	 * we will write it.
-	 */
-	for (j = 0; j < bitmap->storage.file_pages; j++)
-		if (test_and_clear_page_attr(bitmap, j,
-					     BITMAP_PAGE_PENDING))
-			set_page_attr(bitmap, j,
-				      BITMAP_PAGE_NEEDWRITE);
-
-	if (bitmap->need_sync &&
-	    mddev->bitmap_info.external == 0) {
-		/* Arrange for superblock update as well as
-		 * other changes */
-		bitmap_super_t *sb;
-		bitmap->need_sync = 0;
-		if (bitmap->storage.filemap) {
-			sb = kmap_atomic(bitmap->storage.sb_page);
-			sb->events_cleared =
-				cpu_to_le64(bitmap->events_cleared);
-			kunmap_atomic(sb);
-			set_page_attr(bitmap, 0,
-				      BITMAP_PAGE_NEEDWRITE);
-		}
-	}
-	/* Now look at the bitmap counters and if any are '2' or '1',
-	 * decrement and handle accordingly.
-	 */
-	counts = &bitmap->counts;
-	spin_lock_irq(&counts->lock);
-	nextpage = 0;
-	for (j = 0; j < counts->chunks; j++) {
-		bitmap_counter_t *bmc;
-		sector_t  block = (sector_t)j << counts->chunkshift;
-
-		if (j == nextpage) {
-			nextpage += PAGE_COUNTER_RATIO;
-			if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
-				j |= PAGE_COUNTER_MASK;
-				continue;
-			}
-			counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
-		}
-		bmc = bitmap_get_counter(counts,
-					 block,
-					 &blocks, 0);
-
-		if (!bmc) {
-			j |= PAGE_COUNTER_MASK;
-			continue;
-		}
-		if (*bmc == 1 && !bitmap->need_sync) {
-			/* We can clear the bit */
-			*bmc = 0;
-			bitmap_count_page(counts, block, -1);
-			bitmap_file_clear_bit(bitmap, block);
-		} else if (*bmc && *bmc <= 2) {
-			*bmc = 1;
-			bitmap_set_pending(counts, block);
-			bitmap->allclean = 0;
-		}
-	}
-	spin_unlock_irq(&counts->lock);
-
-	bitmap_wait_writes(bitmap);
-	/* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
-	 * DIRTY pages need to be written by bitmap_unplug so it can wait
-	 * for them.
-	 * If we find any DIRTY page we stop there and let bitmap_unplug
-	 * handle all the rest.  This is important in the case where
-	 * the first blocking holds the superblock and it has been updated.
-	 * We mustn't write any other blocks before the superblock.
-	 */
-	for (j = 0;
-	     j < bitmap->storage.file_pages
-		     && !test_bit(BITMAP_STALE, &bitmap->flags);
-	     j++) {
-		if (test_page_attr(bitmap, j,
-				   BITMAP_PAGE_DIRTY))
-			/* bitmap_unplug will handle the rest */
-			break;
-		if (test_and_clear_page_attr(bitmap, j,
-					     BITMAP_PAGE_NEEDWRITE)) {
-			write_page(bitmap, bitmap->storage.filemap[j], 0);
-		}
-	}
-
- done:
-	if (bitmap->allclean == 0)
-		mddev->thread->timeout =
-			mddev->bitmap_info.daemon_sleep;
-	mutex_unlock(&mddev->bitmap_info.mutex);
-}
-
-static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
-					    sector_t offset, sector_t *blocks,
-					    int create)
-__releases(bitmap->lock)
-__acquires(bitmap->lock)
-{
-	/* If 'create', we might release the lock and reclaim it.
-	 * The lock must have been taken with interrupts enabled.
-	 * If !create, we don't release the lock.
-	 */
-	sector_t chunk = offset >> bitmap->chunkshift;
-	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
-	unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
-	sector_t csize;
-	int err;
-
-	err = bitmap_checkpage(bitmap, page, create, 0);
-
-	if (bitmap->bp[page].hijacked ||
-	    bitmap->bp[page].map == NULL)
-		csize = ((sector_t)1) << (bitmap->chunkshift +
-					  PAGE_COUNTER_SHIFT - 1);
-	else
-		csize = ((sector_t)1) << bitmap->chunkshift;
-	*blocks = csize - (offset & (csize - 1));
-
-	if (err < 0)
-		return NULL;
-
-	/* now locked ... */
-
-	if (bitmap->bp[page].hijacked) { /* hijacked pointer */
-		/* should we use the first or second counter field
-		 * of the hijacked pointer? */
-		int hi = (pageoff > PAGE_COUNTER_MASK);
-		return  &((bitmap_counter_t *)
-			  &bitmap->bp[page].map)[hi];
-	} else /* page is allocated */
-		return (bitmap_counter_t *)
-			&(bitmap->bp[page].map[pageoff]);
-}
-
-int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
-{
-	if (!bitmap)
-		return 0;
-
-	if (behind) {
-		int bw;
-		atomic_inc(&bitmap->behind_writes);
-		bw = atomic_read(&bitmap->behind_writes);
-		if (bw > bitmap->behind_writes_used)
-			bitmap->behind_writes_used = bw;
-
-		pr_debug("inc write-behind count %d/%lu\n",
-			 bw, bitmap->mddev->bitmap_info.max_write_behind);
-	}
-
-	while (sectors) {
-		sector_t blocks;
-		bitmap_counter_t *bmc;
-
-		spin_lock_irq(&bitmap->counts.lock);
-		bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
-		if (!bmc) {
-			spin_unlock_irq(&bitmap->counts.lock);
-			return 0;
-		}
-
-		if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
-			DEFINE_WAIT(__wait);
-			/* note that it is safe to do the prepare_to_wait
-			 * after the test as long as we do it before dropping
-			 * the spinlock.
-			 */
-			prepare_to_wait(&bitmap->overflow_wait, &__wait,
-					TASK_UNINTERRUPTIBLE);
-			spin_unlock_irq(&bitmap->counts.lock);
-			schedule();
-			finish_wait(&bitmap->overflow_wait, &__wait);
-			continue;
-		}
-
-		switch (*bmc) {
-		case 0:
-			bitmap_file_set_bit(bitmap, offset);
-			bitmap_count_page(&bitmap->counts, offset, 1);
-			/* fall through */
-		case 1:
-			*bmc = 2;
-		}
-
-		(*bmc)++;
-
-		spin_unlock_irq(&bitmap->counts.lock);
-
-		offset += blocks;
-		if (sectors > blocks)
-			sectors -= blocks;
-		else
-			sectors = 0;
-	}
-	return 0;
-}
-EXPORT_SYMBOL(bitmap_startwrite);
-
-void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
-		     int success, int behind)
-{
-	if (!bitmap)
-		return;
-	if (behind) {
-		if (atomic_dec_and_test(&bitmap->behind_writes))
-			wake_up(&bitmap->behind_wait);
-		pr_debug("dec write-behind count %d/%lu\n",
-			 atomic_read(&bitmap->behind_writes),
-			 bitmap->mddev->bitmap_info.max_write_behind);
-	}
-
-	while (sectors) {
-		sector_t blocks;
-		unsigned long flags;
-		bitmap_counter_t *bmc;
-
-		spin_lock_irqsave(&bitmap->counts.lock, flags);
-		bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
-		if (!bmc) {
-			spin_unlock_irqrestore(&bitmap->counts.lock, flags);
-			return;
-		}
-
-		if (success && !bitmap->mddev->degraded &&
-		    bitmap->events_cleared < bitmap->mddev->events) {
-			bitmap->events_cleared = bitmap->mddev->events;
-			bitmap->need_sync = 1;
-			sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
-		}
-
-		if (!success && !NEEDED(*bmc))
-			*bmc |= NEEDED_MASK;
-
-		if (COUNTER(*bmc) == COUNTER_MAX)
-			wake_up(&bitmap->overflow_wait);
-
-		(*bmc)--;
-		if (*bmc <= 2) {
-			bitmap_set_pending(&bitmap->counts, offset);
-			bitmap->allclean = 0;
-		}
-		spin_unlock_irqrestore(&bitmap->counts.lock, flags);
-		offset += blocks;
-		if (sectors > blocks)
-			sectors -= blocks;
-		else
-			sectors = 0;
-	}
-}
-EXPORT_SYMBOL(bitmap_endwrite);
-
-static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
-			       int degraded)
-{
-	bitmap_counter_t *bmc;
-	int rv;
-	if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
-		*blocks = 1024;
-		return 1; /* always resync if no bitmap */
-	}
-	spin_lock_irq(&bitmap->counts.lock);
-	bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
-	rv = 0;
-	if (bmc) {
-		/* locked */
-		if (RESYNC(*bmc))
-			rv = 1;
-		else if (NEEDED(*bmc)) {
-			rv = 1;
-			if (!degraded) { /* don't set/clear bits if degraded */
-				*bmc |= RESYNC_MASK;
-				*bmc &= ~NEEDED_MASK;
-			}
-		}
-	}
-	spin_unlock_irq(&bitmap->counts.lock);
-	return rv;
-}
-
-int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
-		      int degraded)
-{
-	/* bitmap_start_sync must always report on multiples of whole
-	 * pages, otherwise resync (which is very PAGE_SIZE based) will
-	 * get confused.
-	 * So call __bitmap_start_sync repeatedly (if needed) until
-	 * At least PAGE_SIZE>>9 blocks are covered.
-	 * Return the 'or' of the result.
-	 */
-	int rv = 0;
-	sector_t blocks1;
-
-	*blocks = 0;
-	while (*blocks < (PAGE_SIZE>>9)) {
-		rv |= __bitmap_start_sync(bitmap, offset,
-					  &blocks1, degraded);
-		offset += blocks1;
-		*blocks += blocks1;
-	}
-	return rv;
-}
-EXPORT_SYMBOL(bitmap_start_sync);
-
-void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
-{
-	bitmap_counter_t *bmc;
-	unsigned long flags;
-
-	if (bitmap == NULL) {
-		*blocks = 1024;
-		return;
-	}
-	spin_lock_irqsave(&bitmap->counts.lock, flags);
-	bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
-	if (bmc == NULL)
-		goto unlock;
-	/* locked */
-	if (RESYNC(*bmc)) {
-		*bmc &= ~RESYNC_MASK;
-
-		if (!NEEDED(*bmc) && aborted)
-			*bmc |= NEEDED_MASK;
-		else {
-			if (*bmc <= 2) {
-				bitmap_set_pending(&bitmap->counts, offset);
-				bitmap->allclean = 0;
-			}
-		}
-	}
- unlock:
-	spin_unlock_irqrestore(&bitmap->counts.lock, flags);
-}
-EXPORT_SYMBOL(bitmap_end_sync);
-
-void bitmap_close_sync(struct bitmap *bitmap)
-{
-	/* Sync has finished, and any bitmap chunks that weren't synced
-	 * properly have been aborted.  It remains to us to clear the
-	 * RESYNC bit wherever it is still on
-	 */
-	sector_t sector = 0;
-	sector_t blocks;
-	if (!bitmap)
-		return;
-	while (sector < bitmap->mddev->resync_max_sectors) {
-		bitmap_end_sync(bitmap, sector, &blocks, 0);
-		sector += blocks;
-	}
-}
-EXPORT_SYMBOL(bitmap_close_sync);
-
-void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
-{
-	sector_t s = 0;
-	sector_t blocks;
-
-	if (!bitmap)
-		return;
-	if (sector == 0) {
-		bitmap->last_end_sync = jiffies;
-		return;
-	}
-	if (!force && time_before(jiffies, (bitmap->last_end_sync
-				  + bitmap->mddev->bitmap_info.daemon_sleep)))
-		return;
-	wait_event(bitmap->mddev->recovery_wait,
-		   atomic_read(&bitmap->mddev->recovery_active) == 0);
-
-	bitmap->mddev->curr_resync_completed = sector;
-	set_bit(MD_SB_CHANGE_CLEAN, &bitmap->mddev->sb_flags);
-	sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
-	s = 0;
-	while (s < sector && s < bitmap->mddev->resync_max_sectors) {
-		bitmap_end_sync(bitmap, s, &blocks, 0);
-		s += blocks;
-	}
-	bitmap->last_end_sync = jiffies;
-	sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
-}
-EXPORT_SYMBOL(bitmap_cond_end_sync);
-
-void bitmap_sync_with_cluster(struct mddev *mddev,
-			      sector_t old_lo, sector_t old_hi,
-			      sector_t new_lo, sector_t new_hi)
-{
-	struct bitmap *bitmap = mddev->bitmap;
-	sector_t sector, blocks = 0;
-
-	for (sector = old_lo; sector < new_lo; ) {
-		bitmap_end_sync(bitmap, sector, &blocks, 0);
-		sector += blocks;
-	}
-	WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
-
-	for (sector = old_hi; sector < new_hi; ) {
-		bitmap_start_sync(bitmap, sector, &blocks, 0);
-		sector += blocks;
-	}
-	WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
-}
-EXPORT_SYMBOL(bitmap_sync_with_cluster);
-
-static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
-{
-	/* For each chunk covered by any of these sectors, set the
-	 * counter to 2 and possibly set resync_needed.  They should all
-	 * be 0 at this point
-	 */
-
-	sector_t secs;
-	bitmap_counter_t *bmc;
-	spin_lock_irq(&bitmap->counts.lock);
-	bmc = bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
-	if (!bmc) {
-		spin_unlock_irq(&bitmap->counts.lock);
-		return;
-	}
-	if (!*bmc) {
-		*bmc = 2;
-		bitmap_count_page(&bitmap->counts, offset, 1);
-		bitmap_set_pending(&bitmap->counts, offset);
-		bitmap->allclean = 0;
-	}
-	if (needed)
-		*bmc |= NEEDED_MASK;
-	spin_unlock_irq(&bitmap->counts.lock);
-}
-
-/* dirty the memory and file bits for bitmap chunks "s" to "e" */
-void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
-{
-	unsigned long chunk;
-
-	for (chunk = s; chunk <= e; chunk++) {
-		sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
-		bitmap_set_memory_bits(bitmap, sec, 1);
-		bitmap_file_set_bit(bitmap, sec);
-		if (sec < bitmap->mddev->recovery_cp)
-			/* We are asserting that the array is dirty,
-			 * so move the recovery_cp address back so
-			 * that it is obvious that it is dirty
-			 */
-			bitmap->mddev->recovery_cp = sec;
-	}
-}
-
-/*
- * flush out any pending updates
- */
-void bitmap_flush(struct mddev *mddev)
-{
-	struct bitmap *bitmap = mddev->bitmap;
-	long sleep;
-
-	if (!bitmap) /* there was no bitmap */
-		return;
-
-	/* run the daemon_work three time to ensure everything is flushed
-	 * that can be
-	 */
-	sleep = mddev->bitmap_info.daemon_sleep * 2;
-	bitmap->daemon_lastrun -= sleep;
-	bitmap_daemon_work(mddev);
-	bitmap->daemon_lastrun -= sleep;
-	bitmap_daemon_work(mddev);
-	bitmap->daemon_lastrun -= sleep;
-	bitmap_daemon_work(mddev);
-	bitmap_update_sb(bitmap);
-}
-
-/*
- * free memory that was allocated
- */
-void bitmap_free(struct bitmap *bitmap)
-{
-	unsigned long k, pages;
-	struct bitmap_page *bp;
-
-	if (!bitmap) /* there was no bitmap */
-		return;
-
-	if (bitmap->sysfs_can_clear)
-		sysfs_put(bitmap->sysfs_can_clear);
-
-	if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
-		bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
-		md_cluster_stop(bitmap->mddev);
-
-	/* Shouldn't be needed - but just in case.... */
-	wait_event(bitmap->write_wait,
-		   atomic_read(&bitmap->pending_writes) == 0);
-
-	/* release the bitmap file  */
-	bitmap_file_unmap(&bitmap->storage);
-
-	bp = bitmap->counts.bp;
-	pages = bitmap->counts.pages;
-
-	/* free all allocated memory */
-
-	if (bp) /* deallocate the page memory */
-		for (k = 0; k < pages; k++)
-			if (bp[k].map && !bp[k].hijacked)
-				kfree(bp[k].map);
-	kfree(bp);
-	kfree(bitmap);
-}
-EXPORT_SYMBOL(bitmap_free);
-
-void bitmap_wait_behind_writes(struct mddev *mddev)
-{
-	struct bitmap *bitmap = mddev->bitmap;
-
-	/* wait for behind writes to complete */
-	if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
-		pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
-			 mdname(mddev));
-		/* need to kick something here to make sure I/O goes? */
-		wait_event(bitmap->behind_wait,
-			   atomic_read(&bitmap->behind_writes) == 0);
-	}
-}
-
-void bitmap_destroy(struct mddev *mddev)
-{
-	struct bitmap *bitmap = mddev->bitmap;
-
-	if (!bitmap) /* there was no bitmap */
-		return;
-
-	bitmap_wait_behind_writes(mddev);
-
-	mutex_lock(&mddev->bitmap_info.mutex);
-	spin_lock(&mddev->lock);
-	mddev->bitmap = NULL; /* disconnect from the md device */
-	spin_unlock(&mddev->lock);
-	mutex_unlock(&mddev->bitmap_info.mutex);
-	if (mddev->thread)
-		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
-
-	bitmap_free(bitmap);
-}
-
-/*
- * initialize the bitmap structure
- * if this returns an error, bitmap_destroy must be called to do clean up
- * once mddev->bitmap is set
- */
-struct bitmap *bitmap_create(struct mddev *mddev, int slot)
-{
-	struct bitmap *bitmap;
-	sector_t blocks = mddev->resync_max_sectors;
-	struct file *file = mddev->bitmap_info.file;
-	int err;
-	struct kernfs_node *bm = NULL;
-
-	BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
-
-	BUG_ON(file && mddev->bitmap_info.offset);
-
-	bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
-	if (!bitmap)
-		return ERR_PTR(-ENOMEM);
-
-	spin_lock_init(&bitmap->counts.lock);
-	atomic_set(&bitmap->pending_writes, 0);
-	init_waitqueue_head(&bitmap->write_wait);
-	init_waitqueue_head(&bitmap->overflow_wait);
-	init_waitqueue_head(&bitmap->behind_wait);
-
-	bitmap->mddev = mddev;
-	bitmap->cluster_slot = slot;
-
-	if (mddev->kobj.sd)
-		bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
-	if (bm) {
-		bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
-		sysfs_put(bm);
-	} else
-		bitmap->sysfs_can_clear = NULL;
-
-	bitmap->storage.file = file;
-	if (file) {
-		get_file(file);
-		/* As future accesses to this file will use bmap,
-		 * and bypass the page cache, we must sync the file
-		 * first.
-		 */
-		vfs_fsync(file, 1);
-	}
-	/* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
-	if (!mddev->bitmap_info.external) {
-		/*
-		 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
-		 * instructing us to create a new on-disk bitmap instance.
-		 */
-		if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
-			err = bitmap_new_disk_sb(bitmap);
-		else
-			err = bitmap_read_sb(bitmap);
-	} else {
-		err = 0;
-		if (mddev->bitmap_info.chunksize == 0 ||
-		    mddev->bitmap_info.daemon_sleep == 0)
-			/* chunksize and time_base need to be
-			 * set first. */
-			err = -EINVAL;
-	}
-	if (err)
-		goto error;
-
-	bitmap->daemon_lastrun = jiffies;
-	err = bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
-	if (err)
-		goto error;
-
-	pr_debug("created bitmap (%lu pages) for device %s\n",
-		 bitmap->counts.pages, bmname(bitmap));
-
-	err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
-	if (err)
-		goto error;
-
-	return bitmap;
- error:
-	bitmap_free(bitmap);
-	return ERR_PTR(err);
-}
-
-int bitmap_load(struct mddev *mddev)
-{
-	int err = 0;
-	sector_t start = 0;
-	sector_t sector = 0;
-	struct bitmap *bitmap = mddev->bitmap;
-
-	if (!bitmap)
-		goto out;
-
-	if (mddev_is_clustered(mddev))
-		md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
-
-	/* Clear out old bitmap info first:  Either there is none, or we
-	 * are resuming after someone else has possibly changed things,
-	 * so we should forget old cached info.
-	 * All chunks should be clean, but some might need_sync.
-	 */
-	while (sector < mddev->resync_max_sectors) {
-		sector_t blocks;
-		bitmap_start_sync(bitmap, sector, &blocks, 0);
-		sector += blocks;
-	}
-	bitmap_close_sync(bitmap);
-
-	if (mddev->degraded == 0
-	    || bitmap->events_cleared == mddev->events)
-		/* no need to keep dirty bits to optimise a
-		 * re-add of a missing device */
-		start = mddev->recovery_cp;
-
-	mutex_lock(&mddev->bitmap_info.mutex);
-	err = bitmap_init_from_disk(bitmap, start);
-	mutex_unlock(&mddev->bitmap_info.mutex);
-
-	if (err)
-		goto out;
-	clear_bit(BITMAP_STALE, &bitmap->flags);
-
-	/* Kick recovery in case any bits were set */
-	set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
-
-	mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
-	md_wakeup_thread(mddev->thread);
-
-	bitmap_update_sb(bitmap);
-
-	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
-		err = -EIO;
-out:
-	return err;
-}
-EXPORT_SYMBOL_GPL(bitmap_load);
-
-struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
-{
-	int rv = 0;
-	struct bitmap *bitmap;
-
-	bitmap = bitmap_create(mddev, slot);
-	if (IS_ERR(bitmap)) {
-		rv = PTR_ERR(bitmap);
-		return ERR_PTR(rv);
-	}
-
-	rv = bitmap_init_from_disk(bitmap, 0);
-	if (rv) {
-		bitmap_free(bitmap);
-		return ERR_PTR(rv);
-	}
-
-	return bitmap;
-}
-EXPORT_SYMBOL(get_bitmap_from_slot);
-
-/* Loads the bitmap associated with slot and copies the resync information
- * to our bitmap
- */
-int bitmap_copy_from_slot(struct mddev *mddev, int slot,
-		sector_t *low, sector_t *high, bool clear_bits)
-{
-	int rv = 0, i, j;
-	sector_t block, lo = 0, hi = 0;
-	struct bitmap_counts *counts;
-	struct bitmap *bitmap;
-
-	bitmap = get_bitmap_from_slot(mddev, slot);
-	if (IS_ERR(bitmap)) {
-		pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
-		return -1;
-	}
-
-	counts = &bitmap->counts;
-	for (j = 0; j < counts->chunks; j++) {
-		block = (sector_t)j << counts->chunkshift;
-		if (bitmap_file_test_bit(bitmap, block)) {
-			if (!lo)
-				lo = block;
-			hi = block;
-			bitmap_file_clear_bit(bitmap, block);
-			bitmap_set_memory_bits(mddev->bitmap, block, 1);
-			bitmap_file_set_bit(mddev->bitmap, block);
-		}
-	}
-
-	if (clear_bits) {
-		bitmap_update_sb(bitmap);
-		/* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
-		 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
-		for (i = 0; i < bitmap->storage.file_pages; i++)
-			if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
-				set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
-		bitmap_unplug(bitmap);
-	}
-	bitmap_unplug(mddev->bitmap);
-	*low = lo;
-	*high = hi;
-
-	return rv;
-}
-EXPORT_SYMBOL_GPL(bitmap_copy_from_slot);
-
-
-void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
-{
-	unsigned long chunk_kb;
-	struct bitmap_counts *counts;
-
-	if (!bitmap)
-		return;
-
-	counts = &bitmap->counts;
-
-	chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
-	seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
-		   "%lu%s chunk",
-		   counts->pages - counts->missing_pages,
-		   counts->pages,
-		   (counts->pages - counts->missing_pages)
-		   << (PAGE_SHIFT - 10),
-		   chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
-		   chunk_kb ? "KB" : "B");
-	if (bitmap->storage.file) {
-		seq_printf(seq, ", file: ");
-		seq_file_path(seq, bitmap->storage.file, " \t\n");
-	}
-
-	seq_printf(seq, "\n");
-}
-
-int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
-		  int chunksize, int init)
-{
-	/* If chunk_size is 0, choose an appropriate chunk size.
-	 * Then possibly allocate new storage space.
-	 * Then quiesce, copy bits, replace bitmap, and re-start
-	 *
-	 * This function is called both to set up the initial bitmap
-	 * and to resize the bitmap while the array is active.
-	 * If this happens as a result of the array being resized,
-	 * chunksize will be zero, and we need to choose a suitable
-	 * chunksize, otherwise we use what we are given.
-	 */
-	struct bitmap_storage store;
-	struct bitmap_counts old_counts;
-	unsigned long chunks;
-	sector_t block;
-	sector_t old_blocks, new_blocks;
-	int chunkshift;
-	int ret = 0;
-	long pages;
-	struct bitmap_page *new_bp;
-
-	if (bitmap->storage.file && !init) {
-		pr_info("md: cannot resize file-based bitmap\n");
-		return -EINVAL;
-	}
-
-	if (chunksize == 0) {
-		/* If there is enough space, leave the chunk size unchanged,
-		 * else increase by factor of two until there is enough space.
-		 */
-		long bytes;
-		long space = bitmap->mddev->bitmap_info.space;
-
-		if (space == 0) {
-			/* We don't know how much space there is, so limit
-			 * to current size - in sectors.
-			 */
-			bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
-			if (!bitmap->mddev->bitmap_info.external)
-				bytes += sizeof(bitmap_super_t);
-			space = DIV_ROUND_UP(bytes, 512);
-			bitmap->mddev->bitmap_info.space = space;
-		}
-		chunkshift = bitmap->counts.chunkshift;
-		chunkshift--;
-		do {
-			/* 'chunkshift' is shift from block size to chunk size */
-			chunkshift++;
-			chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
-			bytes = DIV_ROUND_UP(chunks, 8);
-			if (!bitmap->mddev->bitmap_info.external)
-				bytes += sizeof(bitmap_super_t);
-		} while (bytes > (space << 9));
-	} else
-		chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
-
-	chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
-	memset(&store, 0, sizeof(store));
-	if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
-		ret = bitmap_storage_alloc(&store, chunks,
-					   !bitmap->mddev->bitmap_info.external,
-					   mddev_is_clustered(bitmap->mddev)
-					   ? bitmap->cluster_slot : 0);
-	if (ret) {
-		bitmap_file_unmap(&store);
-		goto err;
-	}
-
-	pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
-
-	new_bp = kzalloc(pages * sizeof(*new_bp), GFP_KERNEL);
-	ret = -ENOMEM;
-	if (!new_bp) {
-		bitmap_file_unmap(&store);
-		goto err;
-	}
-
-	if (!init)
-		bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
-
-	store.file = bitmap->storage.file;
-	bitmap->storage.file = NULL;
-
-	if (store.sb_page && bitmap->storage.sb_page)
-		memcpy(page_address(store.sb_page),
-		       page_address(bitmap->storage.sb_page),
-		       sizeof(bitmap_super_t));
-	bitmap_file_unmap(&bitmap->storage);
-	bitmap->storage = store;
-
-	old_counts = bitmap->counts;
-	bitmap->counts.bp = new_bp;
-	bitmap->counts.pages = pages;
-	bitmap->counts.missing_pages = pages;
-	bitmap->counts.chunkshift = chunkshift;
-	bitmap->counts.chunks = chunks;
-	bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift +
-						     BITMAP_BLOCK_SHIFT);
-
-	blocks = min(old_counts.chunks << old_counts.chunkshift,
-		     chunks << chunkshift);
-
-	spin_lock_irq(&bitmap->counts.lock);
-	/* For cluster raid, need to pre-allocate bitmap */
-	if (mddev_is_clustered(bitmap->mddev)) {
-		unsigned long page;
-		for (page = 0; page < pages; page++) {
-			ret = bitmap_checkpage(&bitmap->counts, page, 1, 1);
-			if (ret) {
-				unsigned long k;
-
-				/* deallocate the page memory */
-				for (k = 0; k < page; k++) {
-					kfree(new_bp[k].map);
-				}
-
-				/* restore some fields from old_counts */
-				bitmap->counts.bp = old_counts.bp;
-				bitmap->counts.pages = old_counts.pages;
-				bitmap->counts.missing_pages = old_counts.pages;
-				bitmap->counts.chunkshift = old_counts.chunkshift;
-				bitmap->counts.chunks = old_counts.chunks;
-				bitmap->mddev->bitmap_info.chunksize = 1 << (old_counts.chunkshift +
-									     BITMAP_BLOCK_SHIFT);
-				blocks = old_counts.chunks << old_counts.chunkshift;
-				pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
-				break;
-			} else
-				bitmap->counts.bp[page].count += 1;
-		}
-	}
-
-	for (block = 0; block < blocks; ) {
-		bitmap_counter_t *bmc_old, *bmc_new;
-		int set;
-
-		bmc_old = bitmap_get_counter(&old_counts, block,
-					     &old_blocks, 0);
-		set = bmc_old && NEEDED(*bmc_old);
-
-		if (set) {
-			bmc_new = bitmap_get_counter(&bitmap->counts, block,
-						     &new_blocks, 1);
-			if (*bmc_new == 0) {
-				/* need to set on-disk bits too. */
-				sector_t end = block + new_blocks;
-				sector_t start = block >> chunkshift;
-				start <<= chunkshift;
-				while (start < end) {
-					bitmap_file_set_bit(bitmap, block);
-					start += 1 << chunkshift;
-				}
-				*bmc_new = 2;
-				bitmap_count_page(&bitmap->counts,
-						  block, 1);
-				bitmap_set_pending(&bitmap->counts,
-						   block);
-			}
-			*bmc_new |= NEEDED_MASK;
-			if (new_blocks < old_blocks)
-				old_blocks = new_blocks;
-		}
-		block += old_blocks;
-	}
-
-	if (!init) {
-		int i;
-		while (block < (chunks << chunkshift)) {
-			bitmap_counter_t *bmc;
-			bmc = bitmap_get_counter(&bitmap->counts, block,
-						 &new_blocks, 1);
-			if (bmc) {
-				/* new space.  It needs to be resynced, so
-				 * we set NEEDED_MASK.
-				 */
-				if (*bmc == 0) {
-					*bmc = NEEDED_MASK | 2;
-					bitmap_count_page(&bitmap->counts,
-							  block, 1);
-					bitmap_set_pending(&bitmap->counts,
-							   block);
-				}
-			}
-			block += new_blocks;
-		}
-		for (i = 0; i < bitmap->storage.file_pages; i++)
-			set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
-	}
-	spin_unlock_irq(&bitmap->counts.lock);
-
-	if (!init) {
-		bitmap_unplug(bitmap);
-		bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
-	}
-	ret = 0;
-err:
-	return ret;
-}
-EXPORT_SYMBOL_GPL(bitmap_resize);
-
-static ssize_t
-location_show(struct mddev *mddev, char *page)
-{
-	ssize_t len;
-	if (mddev->bitmap_info.file)
-		len = sprintf(page, "file");
-	else if (mddev->bitmap_info.offset)
-		len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
-	else
-		len = sprintf(page, "none");
-	len += sprintf(page+len, "\n");
-	return len;
-}
-
-static ssize_t
-location_store(struct mddev *mddev, const char *buf, size_t len)
-{
-	int rv;
-
-	rv = mddev_lock(mddev);
-	if (rv)
-		return rv;
-	if (mddev->pers) {
-		if (!mddev->pers->quiesce) {
-			rv = -EBUSY;
-			goto out;
-		}
-		if (mddev->recovery || mddev->sync_thread) {
-			rv = -EBUSY;
-			goto out;
-		}
-	}
-
-	if (mddev->bitmap || mddev->bitmap_info.file ||
-	    mddev->bitmap_info.offset) {
-		/* bitmap already configured.  Only option is to clear it */
-		if (strncmp(buf, "none", 4) != 0) {
-			rv = -EBUSY;
-			goto out;
-		}
-		if (mddev->pers) {
-			mddev->pers->quiesce(mddev, 1);
-			bitmap_destroy(mddev);
-			mddev->pers->quiesce(mddev, 0);
-		}
-		mddev->bitmap_info.offset = 0;
-		if (mddev->bitmap_info.file) {
-			struct file *f = mddev->bitmap_info.file;
-			mddev->bitmap_info.file = NULL;
-			fput(f);
-		}
-	} else {
-		/* No bitmap, OK to set a location */
-		long long offset;
-		if (strncmp(buf, "none", 4) == 0)
-			/* nothing to be done */;
-		else if (strncmp(buf, "file:", 5) == 0) {
-			/* Not supported yet */
-			rv = -EINVAL;
-			goto out;
-		} else {
-			if (buf[0] == '+')
-				rv = kstrtoll(buf+1, 10, &offset);
-			else
-				rv = kstrtoll(buf, 10, &offset);
-			if (rv)
-				goto out;
-			if (offset == 0) {
-				rv = -EINVAL;
-				goto out;
-			}
-			if (mddev->bitmap_info.external == 0 &&
-			    mddev->major_version == 0 &&
-			    offset != mddev->bitmap_info.default_offset) {
-				rv = -EINVAL;
-				goto out;
-			}
-			mddev->bitmap_info.offset = offset;
-			if (mddev->pers) {
-				struct bitmap *bitmap;
-				mddev->pers->quiesce(mddev, 1);
-				bitmap = bitmap_create(mddev, -1);
-				if (IS_ERR(bitmap))
-					rv = PTR_ERR(bitmap);
-				else {
-					mddev->bitmap = bitmap;
-					rv = bitmap_load(mddev);
-					if (rv)
-						mddev->bitmap_info.offset = 0;
-				}
-				mddev->pers->quiesce(mddev, 0);
-				if (rv) {
-					bitmap_destroy(mddev);
-					goto out;
-				}
-			}
-		}
-	}
-	if (!mddev->external) {
-		/* Ensure new bitmap info is stored in
-		 * metadata promptly.
-		 */
-		set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
-		md_wakeup_thread(mddev->thread);
-	}
-	rv = 0;
-out:
-	mddev_unlock(mddev);
-	if (rv)
-		return rv;
-	return len;
-}
-
-static struct md_sysfs_entry bitmap_location =
-__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
-
-/* 'bitmap/space' is the space available at 'location' for the
- * bitmap.  This allows the kernel to know when it is safe to
- * resize the bitmap to match a resized array.
- */
-static ssize_t
-space_show(struct mddev *mddev, char *page)
-{
-	return sprintf(page, "%lu\n", mddev->bitmap_info.space);
-}
-
-static ssize_t
-space_store(struct mddev *mddev, const char *buf, size_t len)
-{
-	unsigned long sectors;
-	int rv;
-
-	rv = kstrtoul(buf, 10, &sectors);
-	if (rv)
-		return rv;
-
-	if (sectors == 0)
-		return -EINVAL;
-
-	if (mddev->bitmap &&
-	    sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
-		return -EFBIG; /* Bitmap is too big for this small space */
-
-	/* could make sure it isn't too big, but that isn't really
-	 * needed - user-space should be careful.
-	 */
-	mddev->bitmap_info.space = sectors;
-	return len;
-}
-
-static struct md_sysfs_entry bitmap_space =
-__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
-
-static ssize_t
-timeout_show(struct mddev *mddev, char *page)
-{
-	ssize_t len;
-	unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
-	unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
-
-	len = sprintf(page, "%lu", secs);
-	if (jifs)
-		len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
-	len += sprintf(page+len, "\n");
-	return len;
-}
-
-static ssize_t
-timeout_store(struct mddev *mddev, const char *buf, size_t len)
-{
-	/* timeout can be set at any time */
-	unsigned long timeout;
-	int rv = strict_strtoul_scaled(buf, &timeout, 4);
-	if (rv)
-		return rv;
-
-	/* just to make sure we don't overflow... */
-	if (timeout >= LONG_MAX / HZ)
-		return -EINVAL;
-
-	timeout = timeout * HZ / 10000;
-
-	if (timeout >= MAX_SCHEDULE_TIMEOUT)
-		timeout = MAX_SCHEDULE_TIMEOUT-1;
-	if (timeout < 1)
-		timeout = 1;
-	mddev->bitmap_info.daemon_sleep = timeout;
-	if (mddev->thread) {
-		/* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
-		 * the bitmap is all clean and we don't need to
-		 * adjust the timeout right now
-		 */
-		if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
-			mddev->thread->timeout = timeout;
-			md_wakeup_thread(mddev->thread);
-		}
-	}
-	return len;
-}
-
-static struct md_sysfs_entry bitmap_timeout =
-__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
-
-static ssize_t
-backlog_show(struct mddev *mddev, char *page)
-{
-	return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
-}
-
-static ssize_t
-backlog_store(struct mddev *mddev, const char *buf, size_t len)
-{
-	unsigned long backlog;
-	int rv = kstrtoul(buf, 10, &backlog);
-	if (rv)
-		return rv;
-	if (backlog > COUNTER_MAX)
-		return -EINVAL;
-	mddev->bitmap_info.max_write_behind = backlog;
-	return len;
-}
-
-static struct md_sysfs_entry bitmap_backlog =
-__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
-
-static ssize_t
-chunksize_show(struct mddev *mddev, char *page)
-{
-	return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
-}
-
-static ssize_t
-chunksize_store(struct mddev *mddev, const char *buf, size_t len)
-{
-	/* Can only be changed when no bitmap is active */
-	int rv;
-	unsigned long csize;
-	if (mddev->bitmap)
-		return -EBUSY;
-	rv = kstrtoul(buf, 10, &csize);
-	if (rv)
-		return rv;
-	if (csize < 512 ||
-	    !is_power_of_2(csize))
-		return -EINVAL;
-	mddev->bitmap_info.chunksize = csize;
-	return len;
-}
-
-static struct md_sysfs_entry bitmap_chunksize =
-__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
-
-static ssize_t metadata_show(struct mddev *mddev, char *page)
-{
-	if (mddev_is_clustered(mddev))
-		return sprintf(page, "clustered\n");
-	return sprintf(page, "%s\n", (mddev->bitmap_info.external
-				      ? "external" : "internal"));
-}
-
-static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
-{
-	if (mddev->bitmap ||
-	    mddev->bitmap_info.file ||
-	    mddev->bitmap_info.offset)
-		return -EBUSY;
-	if (strncmp(buf, "external", 8) == 0)
-		mddev->bitmap_info.external = 1;
-	else if ((strncmp(buf, "internal", 8) == 0) ||
-			(strncmp(buf, "clustered", 9) == 0))
-		mddev->bitmap_info.external = 0;
-	else
-		return -EINVAL;
-	return len;
-}
-
-static struct md_sysfs_entry bitmap_metadata =
-__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
-
-static ssize_t can_clear_show(struct mddev *mddev, char *page)
-{
-	int len;
-	spin_lock(&mddev->lock);
-	if (mddev->bitmap)
-		len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
-					     "false" : "true"));
-	else
-		len = sprintf(page, "\n");
-	spin_unlock(&mddev->lock);
-	return len;
-}
-
-static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
-{
-	if (mddev->bitmap == NULL)
-		return -ENOENT;
-	if (strncmp(buf, "false", 5) == 0)
-		mddev->bitmap->need_sync = 1;
-	else if (strncmp(buf, "true", 4) == 0) {
-		if (mddev->degraded)
-			return -EBUSY;
-		mddev->bitmap->need_sync = 0;
-	} else
-		return -EINVAL;
-	return len;
-}
-
-static struct md_sysfs_entry bitmap_can_clear =
-__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
-
-static ssize_t
-behind_writes_used_show(struct mddev *mddev, char *page)
-{
-	ssize_t ret;
-	spin_lock(&mddev->lock);
-	if (mddev->bitmap == NULL)
-		ret = sprintf(page, "0\n");
-	else
-		ret = sprintf(page, "%lu\n",
-			      mddev->bitmap->behind_writes_used);
-	spin_unlock(&mddev->lock);
-	return ret;
-}
-
-static ssize_t
-behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
-{
-	if (mddev->bitmap)
-		mddev->bitmap->behind_writes_used = 0;
-	return len;
-}
-
-static struct md_sysfs_entry max_backlog_used =
-__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
-       behind_writes_used_show, behind_writes_used_reset);
-
-static struct attribute *md_bitmap_attrs[] = {
-	&bitmap_location.attr,
-	&bitmap_space.attr,
-	&bitmap_timeout.attr,
-	&bitmap_backlog.attr,
-	&bitmap_chunksize.attr,
-	&bitmap_metadata.attr,
-	&bitmap_can_clear.attr,
-	&max_backlog_used.attr,
-	NULL
-};
-struct attribute_group md_bitmap_group = {
-	.name = "bitmap",
-	.attrs = md_bitmap_attrs,
-};
-