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From 935fe0983e09f4f7331ebf5ea4ae2124f6e9f9e8 Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Tue, 10 Oct 2017 17:02:41 -0400
Subject: [PATCH] md: rename some drivers/md/ files to have an "md-" prefix
Git-commit: 935fe0983e09f4f7331ebf5ea4ae2124f6e9f9e8
Patch-mainline: v4.15-rc1
References: bsc#1093023

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>
Signed-off-by: Coly Li <colyli@suse.de>

---
 MAINTAINERS                                | 7 ++++++-
 drivers/md/Makefile                        | 5 ++++-
 drivers/md/dm-raid.c                       | 2 +-
 drivers/md/{bitmap.c => md-bitmap.c}       | 2 +-
 drivers/md/{bitmap.h => md-bitmap.h}       | 0
 drivers/md/md-cluster.c                    | 2 +-
 drivers/md/{faulty.c => md-faulty.c}       | 0
 drivers/md/{linear.c => md-linear.c}       | 2 +-
 drivers/md/{linear.h => md-linear.h}       | 0
 drivers/md/{multipath.c => md-multipath.c} | 2 +-
 drivers/md/{multipath.h => md-multipath.h} | 0
 MAINTAINERS               |    7 
 drivers/md/Makefile       |    5 
 drivers/md/bitmap.c       | 2591 ----------------------------------------------
 drivers/md/bitmap.h       |  277 ----
 drivers/md/dm-raid.c      |    2 
 drivers/md/faulty.c       |  372 ------
 drivers/md/linear.c       |  348 ------
 drivers/md/linear.h       |   16 
 drivers/md/md-bitmap.c    | 2591 ++++++++++++++++++++++++++++++++++++++++++++++
 drivers/md/md-bitmap.h    |  277 ++++
 drivers/md/md-cluster.c   |    2 
 drivers/md/md-faulty.c    |  372 ++++++
 drivers/md/md-linear.c    |  348 ++++++
 drivers/md/md-linear.h    |   16 
 drivers/md/md-multipath.c |  509 +++++++++
 drivers/md/md-multipath.h |   31 
 drivers/md/md.c           |    2 
 drivers/md/multipath.c    |  509 ---------
 drivers/md/multipath.h    |   31 
 drivers/md/raid1.c        |    2 
 drivers/md/raid10.c       |    2 
 drivers/md/raid5-cache.c  |    2 
 drivers/md/raid5.c        |    2 
 23 files changed, 4161 insertions(+), 4153 deletions(-)
 rename drivers/md/{bitmap.c => md-bitmap.c} (99%)
 rename drivers/md/{bitmap.h => md-bitmap.h} (100%)
 rename drivers/md/{faulty.c => md-faulty.c} (100%)
 rename drivers/md/{linear.c => md-linear.c} (99%)
 rename drivers/md/{linear.h => md-linear.h} (100%)
 rename drivers/md/{multipath.c => md-multipath.c} (99%)
 rename drivers/md/{multipath.h => md-multipath.h} (100%)

--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3968,6 +3968,8 @@ T:	git git://git.kernel.org/pub/scm/linu
 T:	quilt http://people.redhat.com/agk/patches/linux/editing/
 S:	Maintained
 F:	Documentation/device-mapper/
+F:	drivers/md/Makefile
+F:	drivers/md/Kconfig
 F:	drivers/md/dm*
 F:	drivers/md/persistent-data/
 F:	include/linux/device-mapper.h
@@ -12008,7 +12010,10 @@ M:	Shaohua Li <shli@kernel.org>
 L:	linux-raid@vger.kernel.org
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/shli/md.git
 S:	Supported
-F:	drivers/md/
+F:	drivers/md/Makefile
+F:	drivers/md/Kconfig
+F:	drivers/md/md*
+F:	drivers/md/raid*
 F:	include/linux/raid/
 F:	include/uapi/linux/raid/
 
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -18,9 +18,12 @@ dm-cache-y	+= dm-cache-target.o dm-cache
 dm-cache-smq-y   += dm-cache-policy-smq.o
 dm-era-y	+= dm-era-target.o
 dm-verity-y	+= dm-verity-target.o
-md-mod-y	+= md.o bitmap.o
+md-mod-y	+= md.o md-bitmap.o
 raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
 dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
+linear-y	+= md-linear.o
+multipath-y	+= md-multipath.o
+faulty-y	+= md-faulty.o
 
 # Note: link order is important.  All raid personalities
 # and must come before md.o, as they each initialise 
--- 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, false);
-	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,
-};
-
--- a/drivers/md/bitmap.h
+++ /dev/null
@@ -1,277 +0,0 @@
-/*
- * bitmap.h: Copyright (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
- *
- * additions: Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
- */
-#ifndef BITMAP_H
-#define BITMAP_H 1
-
-#define BITMAP_MAJOR_LO 3
-/* version 4 insists the bitmap is in little-endian order
- * with version 3, it is host-endian which is non-portable
- * Version 5 is currently set only for clustered devices
- */
-#define BITMAP_MAJOR_HI 4
-#define BITMAP_MAJOR_CLUSTERED 5
-#define	BITMAP_MAJOR_HOSTENDIAN 3
-
-/*
- * in-memory bitmap:
- *
- * Use 16 bit block counters to track pending writes to each "chunk".
- * The 2 high order bits are special-purpose, the first is a flag indicating
- * whether a resync is needed.  The second is a flag indicating whether a
- * resync is active.
- * This means that the counter is actually 14 bits:
- *
- * +--------+--------+------------------------------------------------+
- * | resync | resync |               counter                          |
- * | needed | active |                                                |
- * |  (0-1) |  (0-1) |              (0-16383)                         |
- * +--------+--------+------------------------------------------------+
- *
- * The "resync needed" bit is set when:
- *    a '1' bit is read from storage at startup.
- *    a write request fails on some drives
- *    a resync is aborted on a chunk with 'resync active' set
- * It is cleared (and resync-active set) when a resync starts across all drives
- * of the chunk.
- *
- *
- * The "resync active" bit is set when:
- *    a resync is started on all drives, and resync_needed is set.
- *       resync_needed will be cleared (as long as resync_active wasn't already set).
- * It is cleared when a resync completes.
- *
- * The counter counts pending write requests, plus the on-disk bit.
- * When the counter is '1' and the resync bits are clear, the on-disk
- * bit can be cleared as well, thus setting the counter to 0.
- * When we set a bit, or in the counter (to start a write), if the fields is
- * 0, we first set the disk bit and set the counter to 1.
- *
- * If the counter is 0, the on-disk bit is clear and the stripe is clean
- * Anything that dirties the stripe pushes the counter to 2 (at least)
- * and sets the on-disk bit (lazily).
- * If a periodic sweep find the counter at 2, it is decremented to 1.
- * If the sweep find the counter at 1, the on-disk bit is cleared and the
- * counter goes to zero.
- *
- * Also, we'll hijack the "map" pointer itself and use it as two 16 bit block
- * counters as a fallback when "page" memory cannot be allocated:
- *
- * Normal case (page memory allocated):
- *
- *     page pointer (32-bit)
- *
- *     [ ] ------+
- *               |
- *               +-------> [   ][   ]..[   ] (4096 byte page == 2048 counters)
- *                          c1   c2    c2048
- *
- * Hijacked case (page memory allocation failed):
- *
- *     hijacked page pointer (32-bit)
- *
- *     [		  ][		  ] (no page memory allocated)
- *      counter #1 (16-bit) counter #2 (16-bit)
- *
- */
-
-#ifdef __KERNEL__
-
-#define PAGE_BITS (PAGE_SIZE << 3)
-#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3)
-
-typedef __u16 bitmap_counter_t;
-#define COUNTER_BITS 16
-#define COUNTER_BIT_SHIFT 4
-#define COUNTER_BYTE_SHIFT (COUNTER_BIT_SHIFT - 3)
-
-#define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1)))
-#define RESYNC_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 2)))
-#define COUNTER_MAX ((bitmap_counter_t) RESYNC_MASK - 1)
-#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
-#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK)
-#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX)
-
-/* how many counters per page? */
-#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS)
-/* same, except a shift value for more efficient bitops */
-#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT)
-/* same, except a mask value for more efficient bitops */
-#define PAGE_COUNTER_MASK  (PAGE_COUNTER_RATIO - 1)
-
-#define BITMAP_BLOCK_SHIFT 9
-
-#endif
-
-/*
- * bitmap structures:
- */
-
-#define BITMAP_MAGIC 0x6d746962
-
-/* use these for bitmap->flags and bitmap->sb->state bit-fields */
-enum bitmap_state {
-	BITMAP_STALE	   = 1,  /* the bitmap file is out of date or had -EIO */
-	BITMAP_WRITE_ERROR = 2, /* A write error has occurred */
-	BITMAP_HOSTENDIAN  =15,
-};
-
-/* the superblock at the front of the bitmap file -- little endian */
-typedef struct bitmap_super_s {
-	__le32 magic;        /*  0  BITMAP_MAGIC */
-	__le32 version;      /*  4  the bitmap major for now, could change... */
-	__u8  uuid[16];      /*  8  128 bit uuid - must match md device uuid */
-	__le64 events;       /* 24  event counter for the bitmap (1)*/
-	__le64 events_cleared;/*32  event counter when last bit cleared (2) */
-	__le64 sync_size;    /* 40  the size of the md device's sync range(3) */
-	__le32 state;        /* 48  bitmap state information */
-	__le32 chunksize;    /* 52  the bitmap chunk size in bytes */
-	__le32 daemon_sleep; /* 56  seconds between disk flushes */
-	__le32 write_behind; /* 60  number of outstanding write-behind writes */
-	__le32 sectors_reserved; /* 64 number of 512-byte sectors that are
-				  * reserved for the bitmap. */
-	__le32 nodes;        /* 68 the maximum number of nodes in cluster. */
-	__u8 cluster_name[64]; /* 72 cluster name to which this md belongs */
-	__u8  pad[256 - 136]; /* set to zero */
-} bitmap_super_t;
-
-/* notes:
- * (1) This event counter is updated before the eventcounter in the md superblock
- *    When a bitmap is loaded, it is only accepted if this event counter is equal
- *    to, or one greater than, the event counter in the superblock.
- * (2) This event counter is updated when the other one is *if*and*only*if* the
- *    array is not degraded.  As bits are not cleared when the array is degraded,
- *    this represents the last time that any bits were cleared.
- *    If a device is being added that has an event count with this value or
- *    higher, it is accepted as conforming to the bitmap.
- * (3)This is the number of sectors represented by the bitmap, and is the range that
- *    resync happens across.  For raid1 and raid5/6 it is the size of individual
- *    devices.  For raid10 it is the size of the array.
- */
-
-#ifdef __KERNEL__
-
-/* the in-memory bitmap is represented by bitmap_pages */
-struct bitmap_page {
-	/*
-	 * map points to the actual memory page
-	 */
-	char *map;
-	/*
-	 * in emergencies (when map cannot be alloced), hijack the map
-	 * pointer and use it as two counters itself
-	 */
-	unsigned int hijacked:1;
-	/*
-	 * If any counter in this page is '1' or '2' - and so could be
-	 * cleared then that page is marked as 'pending'
-	 */
-	unsigned int pending:1;
-	/*
-	 * count of dirty bits on the page
-	 */
-	unsigned int  count:30;
-};
-
-/* the main bitmap structure - one per mddev */
-struct bitmap {
-
-	struct bitmap_counts {
-		spinlock_t lock;
-		struct bitmap_page *bp;
-		unsigned long pages;		/* total number of pages
-						 * in the bitmap */
-		unsigned long missing_pages;	/* number of pages
-						 * not yet allocated */
-		unsigned long chunkshift;	/* chunksize = 2^chunkshift
-						 * (for bitops) */
-		unsigned long chunks;		/* Total number of data
-						 * chunks for the array */
-	} counts;
-
-	struct mddev *mddev; /* the md device that the bitmap is for */
-
-	__u64	events_cleared;
-	int need_sync;
-
-	struct bitmap_storage {
-		struct file *file;		/* backing disk file */
-		struct page *sb_page;		/* cached copy of the bitmap
-						 * file superblock */
-		struct page **filemap;		/* list of cache pages for
-						 * the file */
-		unsigned long *filemap_attr;	/* attributes associated
-						 * w/ filemap pages */
-		unsigned long file_pages;	/* number of pages in the file*/
-		unsigned long bytes;		/* total bytes in the bitmap */
-	} storage;
-
-	unsigned long flags;
-
-	int allclean;
-
-	atomic_t behind_writes;
-	unsigned long behind_writes_used; /* highest actual value at runtime */
-
-	/*
-	 * the bitmap daemon - periodically wakes up and sweeps the bitmap
-	 * file, cleaning up bits and flushing out pages to disk as necessary
-	 */
-	unsigned long daemon_lastrun; /* jiffies of last run */
-	unsigned long last_end_sync; /* when we lasted called end_sync to
-				      * update bitmap with resync progress */
-
-	atomic_t pending_writes; /* pending writes to the bitmap file */
-	wait_queue_head_t write_wait;
-	wait_queue_head_t overflow_wait;
-	wait_queue_head_t behind_wait;
-
-	struct kernfs_node *sysfs_can_clear;
-	int cluster_slot;		/* Slot offset for clustered env */
-};
-
-/* the bitmap API */
-
-/* these are used only by md/bitmap */
-struct bitmap *bitmap_create(struct mddev *mddev, int slot);
-int bitmap_load(struct mddev *mddev);
-void bitmap_flush(struct mddev *mddev);
-void bitmap_destroy(struct mddev *mddev);
-
-void bitmap_print_sb(struct bitmap *bitmap);
-void bitmap_update_sb(struct bitmap *bitmap);
-void bitmap_status(struct seq_file *seq, struct bitmap *bitmap);
-
-int  bitmap_setallbits(struct bitmap *bitmap);
-void bitmap_write_all(struct bitmap *bitmap);
-
-void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e);
-
-/* these are exported */
-int bitmap_startwrite(struct bitmap *bitmap, sector_t offset,
-			unsigned long sectors, int behind);
-void bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
-			unsigned long sectors, int success, int behind);
-int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int degraded);
-void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted);
-void bitmap_close_sync(struct bitmap *bitmap);
-void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force);
-void bitmap_sync_with_cluster(struct mddev *mddev,
-			      sector_t old_lo, sector_t old_hi,
-			      sector_t new_lo, sector_t new_hi);
-
-void bitmap_unplug(struct bitmap *bitmap);
-void bitmap_daemon_work(struct mddev *mddev);
-
-int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
-		  int chunksize, int init);
-struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot);
-int bitmap_copy_from_slot(struct mddev *mddev, int slot,
-				sector_t *lo, sector_t *hi, bool clear_bits);
-void bitmap_free(struct bitmap *bitmap);
-void bitmap_wait_behind_writes(struct mddev *mddev);
-#endif
-
-#endif
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -12,7 +12,7 @@
 #include "raid1.h"
 #include "raid5.h"
 #include "raid10.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 
 #include <linux/device-mapper.h>
 
--- a/drivers/md/faulty.c
+++ /dev/null
@@ -1,372 +0,0 @@
-/*
- * faulty.c : Multiple Devices driver for Linux
- *
- * Copyright (C) 2004 Neil Brown
- *
- * fautly-device-simulator personality for md
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * You should have received a copy of the GNU General Public License
- * (for example /usr/src/linux/COPYING); if not, write to the Free
- * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-
-/*
- * The "faulty" personality causes some requests to fail.
- *
- * Possible failure modes are:
- *   reads fail "randomly" but succeed on retry
- *   writes fail "randomly" but succeed on retry
- *   reads for some address fail and then persist until a write
- *   reads for some address fail and then persist irrespective of write
- *   writes for some address fail and persist
- *   all writes fail
- *
- * Different modes can be active at a time, but only
- * one can be set at array creation.  Others can be added later.
- * A mode can be one-shot or recurrent with the recurrence being
- * once in every N requests.
- * The bottom 5 bits of the "layout" indicate the mode.  The
- * remainder indicate a period, or 0 for one-shot.
- *
- * There is an implementation limit on the number of concurrently
- * persisting-faulty blocks. When a new fault is requested that would
- * exceed the limit, it is ignored.
- * All current faults can be clear using a layout of "0".
- *
- * Requests are always sent to the device.  If they are to fail,
- * we clone the bio and insert a new b_end_io into the chain.
- */
-
-#define	WriteTransient	0
-#define	ReadTransient	1
-#define	WritePersistent	2
-#define	ReadPersistent	3
-#define	WriteAll	4 /* doesn't go to device */
-#define	ReadFixable	5
-#define	Modes	6
-
-#define	ClearErrors	31
-#define	ClearFaults	30
-
-#define AllPersist	100 /* internal use only */
-#define	NoPersist	101
-
-#define	ModeMask	0x1f
-#define	ModeShift	5
-
-#define MaxFault	50
-#include <linux/blkdev.h>
-#include <linux/module.h>
-#include <linux/raid/md_u.h>
-#include <linux/slab.h>
-#include "md.h"
-#include <linux/seq_file.h>
-
-
-static void faulty_fail(struct bio *bio)
-{
-	struct bio *b = bio->bi_private;
-
-	b->bi_iter.bi_size = bio->bi_iter.bi_size;
-	b->bi_iter.bi_sector = bio->bi_iter.bi_sector;
-
-	bio_put(bio);
-
-	bio_io_error(b);
-}
-
-struct faulty_conf {
-	int period[Modes];
-	atomic_t counters[Modes];
-	sector_t faults[MaxFault];
-	int	modes[MaxFault];
-	int nfaults;
-	struct md_rdev *rdev;
-};
-
-static int check_mode(struct faulty_conf *conf, int mode)
-{
-	if (conf->period[mode] == 0 &&
-	    atomic_read(&conf->counters[mode]) <= 0)
-		return 0; /* no failure, no decrement */
-
-
-	if (atomic_dec_and_test(&conf->counters[mode])) {
-		if (conf->period[mode])
-			atomic_set(&conf->counters[mode], conf->period[mode]);
-		return 1;
-	}
-	return 0;
-}
-
-static int check_sector(struct faulty_conf *conf, sector_t start, sector_t end, int dir)
-{
-	/* If we find a ReadFixable sector, we fix it ... */
-	int i;
-	for (i=0; i<conf->nfaults; i++)
-		if (conf->faults[i] >= start &&
-		    conf->faults[i] < end) {
-			/* found it ... */
-			switch (conf->modes[i] * 2 + dir) {
-			case WritePersistent*2+WRITE: return 1;
-			case ReadPersistent*2+READ: return 1;
-			case ReadFixable*2+READ: return 1;
-			case ReadFixable*2+WRITE:
-				conf->modes[i] = NoPersist;
-				return 0;
-			case AllPersist*2+READ:
-			case AllPersist*2+WRITE: return 1;
-			default:
-				return 0;
-			}
-		}
-	return 0;
-}
-
-static void add_sector(struct faulty_conf *conf, sector_t start, int mode)
-{
-	int i;
-	int n = conf->nfaults;
-	for (i=0; i<conf->nfaults; i++)
-		if (conf->faults[i] == start) {
-			switch(mode) {
-			case NoPersist: conf->modes[i] = mode; return;
-			case WritePersistent:
-				if (conf->modes[i] == ReadPersistent ||
-				    conf->modes[i] == ReadFixable)
-					conf->modes[i] = AllPersist;
-				else
-					conf->modes[i] = WritePersistent;
-				return;
-			case ReadPersistent:
-				if (conf->modes[i] == WritePersistent)
-					conf->modes[i] = AllPersist;
-				else
-					conf->modes[i] = ReadPersistent;
-				return;
-			case ReadFixable:
-				if (conf->modes[i] == WritePersistent ||
-				    conf->modes[i] == ReadPersistent)
-					conf->modes[i] = AllPersist;
-				else
-					conf->modes[i] = ReadFixable;
-				return;
-			}
-		} else if (conf->modes[i] == NoPersist)
-			n = i;
-
-	if (n >= MaxFault)
-		return;
-	conf->faults[n] = start;
-	conf->modes[n] = mode;
-	if (conf->nfaults == n)
-		conf->nfaults = n+1;
-}
-
-static bool faulty_make_request(struct mddev *mddev, struct bio *bio)
-{
-	struct faulty_conf *conf = mddev->private;
-	int failit = 0;
-
-	if (bio_data_dir(bio) == WRITE) {
-		/* write request */
-		if (atomic_read(&conf->counters[WriteAll])) {
-			/* special case - don't decrement, don't generic_make_request,
-			 * just fail immediately
-			 */
-			bio_io_error(bio);
-			return true;
-		}
-
-		if (check_sector(conf, bio->bi_iter.bi_sector,
-				 bio_end_sector(bio), WRITE))
-			failit = 1;
-		if (check_mode(conf, WritePersistent)) {
-			add_sector(conf, bio->bi_iter.bi_sector,
-				   WritePersistent);
-			failit = 1;
-		}
-		if (check_mode(conf, WriteTransient))
-			failit = 1;
-	} else {
-		/* read request */
-		if (check_sector(conf, bio->bi_iter.bi_sector,
-				 bio_end_sector(bio), READ))
-			failit = 1;
-		if (check_mode(conf, ReadTransient))
-			failit = 1;
-		if (check_mode(conf, ReadPersistent)) {
-			add_sector(conf, bio->bi_iter.bi_sector,
-				   ReadPersistent);
-			failit = 1;
-		}
-		if (check_mode(conf, ReadFixable)) {
-			add_sector(conf, bio->bi_iter.bi_sector,
-				   ReadFixable);
-			failit = 1;
-		}
-	}
-	if (failit) {
-		struct bio *b = bio_clone_fast(bio, GFP_NOIO, mddev->bio_set);
-
-		bio_set_dev(b, conf->rdev->bdev);
-		b->bi_private = bio;
-		b->bi_end_io = faulty_fail;
-		bio = b;
-	} else
-		bio_set_dev(bio, conf->rdev->bdev);
-
-	generic_make_request(bio);
-	return true;
-}
-
-static void faulty_status(struct seq_file *seq, struct mddev *mddev)
-{
-	struct faulty_conf *conf = mddev->private;
-	int n;
-
-	if ((n=atomic_read(&conf->counters[WriteTransient])) != 0)
-		seq_printf(seq, " WriteTransient=%d(%d)",
-			   n, conf->period[WriteTransient]);
-
-	if ((n=atomic_read(&conf->counters[ReadTransient])) != 0)
-		seq_printf(seq, " ReadTransient=%d(%d)",
-			   n, conf->period[ReadTransient]);
-
-	if ((n=atomic_read(&conf->counters[WritePersistent])) != 0)
-		seq_printf(seq, " WritePersistent=%d(%d)",
-			   n, conf->period[WritePersistent]);
-
-	if ((n=atomic_read(&conf->counters[ReadPersistent])) != 0)
-		seq_printf(seq, " ReadPersistent=%d(%d)",
-			   n, conf->period[ReadPersistent]);
-
-
-	if ((n=atomic_read(&conf->counters[ReadFixable])) != 0)
-		seq_printf(seq, " ReadFixable=%d(%d)",
-			   n, conf->period[ReadFixable]);
-
-	if ((n=atomic_read(&conf->counters[WriteAll])) != 0)
-		seq_printf(seq, " WriteAll");
-
-	seq_printf(seq, " nfaults=%d", conf->nfaults);
-}
-
-
-static int faulty_reshape(struct mddev *mddev)
-{
-	int mode = mddev->new_layout & ModeMask;
-	int count = mddev->new_layout >> ModeShift;
-	struct faulty_conf *conf = mddev->private;
-
-	if (mddev->new_layout < 0)
-		return 0;
-
-	/* new layout */
-	if (mode == ClearFaults)
-		conf->nfaults = 0;
-	else if (mode == ClearErrors) {
-		int i;
-		for (i=0 ; i < Modes ; i++) {
-			conf->period[i] = 0;
-			atomic_set(&conf->counters[i], 0);
-		}
-	} else if (mode < Modes) {
-		conf->period[mode] = count;
-		if (!count) count++;
-		atomic_set(&conf->counters[mode], count);
-	} else
-		return -EINVAL;
-	mddev->new_layout = -1;
-	mddev->layout = -1; /* makes sure further changes come through */
-	return 0;
-}
-
-static sector_t faulty_size(struct mddev *mddev, sector_t sectors, int raid_disks)
-{
-	WARN_ONCE(raid_disks,
-		  "%s does not support generic reshape\n", __func__);
-
-	if (sectors == 0)
-		return mddev->dev_sectors;
-
-	return sectors;
-}
-
-static int faulty_run(struct mddev *mddev)
-{
-	struct md_rdev *rdev;
-	int i;
-	struct faulty_conf *conf;
-
-	if (md_check_no_bitmap(mddev))
-		return -EINVAL;
-
-	conf = kmalloc(sizeof(*conf), GFP_KERNEL);
-	if (!conf)
-		return -ENOMEM;
-
-	for (i=0; i<Modes; i++) {
-		atomic_set(&conf->counters[i], 0);
-		conf->period[i] = 0;
-	}
-	conf->nfaults = 0;
-
-	rdev_for_each(rdev, mddev) {
-		conf->rdev = rdev;
-		disk_stack_limits(mddev->gendisk, rdev->bdev,
-				  rdev->data_offset << 9);
-	}
-
-	md_set_array_sectors(mddev, faulty_size(mddev, 0, 0));
-	mddev->private = conf;
-
-	faulty_reshape(mddev);
-
-	return 0;
-}
-
-static void faulty_free(struct mddev *mddev, void *priv)
-{
-	struct faulty_conf *conf = priv;
-
-	kfree(conf);
-}
-
-static struct md_personality faulty_personality =
-{
-	.name		= "faulty",
-	.level		= LEVEL_FAULTY,
-	.owner		= THIS_MODULE,
-	.make_request	= faulty_make_request,
-	.run		= faulty_run,
-	.free		= faulty_free,
-	.status		= faulty_status,
-	.check_reshape	= faulty_reshape,
-	.size		= faulty_size,
-};
-
-static int __init raid_init(void)
-{
-	return register_md_personality(&faulty_personality);
-}
-
-static void raid_exit(void)
-{
-	unregister_md_personality(&faulty_personality);
-}
-
-module_init(raid_init);
-module_exit(raid_exit);
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Fault injection personality for MD");
-MODULE_ALIAS("md-personality-10"); /* faulty */
-MODULE_ALIAS("md-faulty");
-MODULE_ALIAS("md-level--5");
--- a/drivers/md/linear.c
+++ /dev/null
@@ -1,348 +0,0 @@
-/*
-   linear.c : Multiple Devices driver for Linux
-	      Copyright (C) 1994-96 Marc ZYNGIER
-	      <zyngier@ufr-info-p7.ibp.fr> or
-	      <maz@gloups.fdn.fr>
-
-   Linear mode management functions.
-
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
-
-   You should have received a copy of the GNU General Public License
-   (for example /usr/src/linux/COPYING); if not, write to the Free
-   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-#include <linux/blkdev.h>
-#include <linux/raid/md_u.h>
-#include <linux/seq_file.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <trace/events/block.h>
-#include "md.h"
-#include "linear.h"
-
-/*
- * find which device holds a particular offset
- */
-static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector)
-{
-	int lo, mid, hi;
-	struct linear_conf *conf;
-
-	lo = 0;
-	hi = mddev->raid_disks - 1;
-	conf = mddev->private;
-
-	/*
-	 * Binary Search
-	 */
-
-	while (hi > lo) {
-
-		mid = (hi + lo) / 2;
-		if (sector < conf->disks[mid].end_sector)
-			hi = mid;
-		else
-			lo = mid + 1;
-	}
-
-	return conf->disks + lo;
-}
-
-/*
- * In linear_congested() conf->raid_disks is used as a copy of
- * mddev->raid_disks to iterate conf->disks[], because conf->raid_disks
- * and conf->disks[] are created in linear_conf(), they are always
- * consitent with each other, but mddev->raid_disks does not.
- */
-static int linear_congested(struct mddev *mddev, int bits)
-{
-	struct linear_conf *conf;
-	int i, ret = 0;
-
-	rcu_read_lock();
-	conf = rcu_dereference(mddev->private);
-
-	for (i = 0; i < conf->raid_disks && !ret ; i++) {
-		struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev);
-		ret |= bdi_congested(q->backing_dev_info, bits);
-	}
-
-	rcu_read_unlock();
-	return ret;
-}
-
-static sector_t linear_size(struct mddev *mddev, sector_t sectors, int raid_disks)
-{
-	struct linear_conf *conf;
-	sector_t array_sectors;
-
-	conf = mddev->private;
-	WARN_ONCE(sectors || raid_disks,
-		  "%s does not support generic reshape\n", __func__);
-	array_sectors = conf->array_sectors;
-
-	return array_sectors;
-}
-
-static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
-{
-	struct linear_conf *conf;
-	struct md_rdev *rdev;
-	int i, cnt;
-	bool discard_supported = false;
-
-	conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
-			GFP_KERNEL);
-	if (!conf)
-		return NULL;
-
-	cnt = 0;
-	conf->array_sectors = 0;
-
-	rdev_for_each(rdev, mddev) {
-		int j = rdev->raid_disk;
-		struct dev_info *disk = conf->disks + j;
-		sector_t sectors;
-
-		if (j < 0 || j >= raid_disks || disk->rdev) {
-			pr_warn("md/linear:%s: disk numbering problem. Aborting!\n",
-				mdname(mddev));
-			goto out;
-		}
-
-		disk->rdev = rdev;
-		if (mddev->chunk_sectors) {
-			sectors = rdev->sectors;
-			sector_div(sectors, mddev->chunk_sectors);
-			rdev->sectors = sectors * mddev->chunk_sectors;
-		}
-
-		disk_stack_limits(mddev->gendisk, rdev->bdev,
-				  rdev->data_offset << 9);
-
-		conf->array_sectors += rdev->sectors;
-		cnt++;
-
-		if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
-			discard_supported = true;
-	}
-	if (cnt != raid_disks) {
-		pr_warn("md/linear:%s: not enough drives present. Aborting!\n",
-			mdname(mddev));
-		goto out;
-	}
-
-	if (!discard_supported)
-		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
-	else
-		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
-
-	/*
-	 * Here we calculate the device offsets.
-	 */
-	conf->disks[0].end_sector = conf->disks[0].rdev->sectors;
-
-	for (i = 1; i < raid_disks; i++)
-		conf->disks[i].end_sector =
-			conf->disks[i-1].end_sector +
-			conf->disks[i].rdev->sectors;
-
-	/*
-	 * conf->raid_disks is copy of mddev->raid_disks. The reason to
-	 * keep a copy of mddev->raid_disks in struct linear_conf is,
-	 * mddev->raid_disks may not be consistent with pointers number of
-	 * conf->disks[] when it is updated in linear_add() and used to
-	 * iterate old conf->disks[] earray in linear_congested().
-	 * Here conf->raid_disks is always consitent with number of
-	 * pointers in conf->disks[] array, and mddev->private is updated
-	 * with rcu_assign_pointer() in linear_addr(), such race can be
-	 * avoided.
-	 */
-	conf->raid_disks = raid_disks;
-
-	return conf;
-
-out:
-	kfree(conf);
-	return NULL;
-}
-
-static int linear_run (struct mddev *mddev)
-{
-	struct linear_conf *conf;
-	int ret;
-
-	if (md_check_no_bitmap(mddev))
-		return -EINVAL;
-	conf = linear_conf(mddev, mddev->raid_disks);
-
-	if (!conf)
-		return 1;
-	mddev->private = conf;
-	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
-
-	ret =  md_integrity_register(mddev);
-	if (ret) {
-		kfree(conf);
-		mddev->private = NULL;
-	}
-	return ret;
-}
-
-static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
-{
-	/* Adding a drive to a linear array allows the array to grow.
-	 * It is permitted if the new drive has a matching superblock
-	 * already on it, with raid_disk equal to raid_disks.
-	 * It is achieved by creating a new linear_private_data structure
-	 * and swapping it in in-place of the current one.
-	 * The current one is never freed until the array is stopped.
-	 * This avoids races.
-	 */
-	struct linear_conf *newconf, *oldconf;
-
-	if (rdev->saved_raid_disk != mddev->raid_disks)
-		return -EINVAL;
-
-	rdev->raid_disk = rdev->saved_raid_disk;
-	rdev->saved_raid_disk = -1;
-
-	newconf = linear_conf(mddev,mddev->raid_disks+1);
-
-	if (!newconf)
-		return -ENOMEM;
-
-	/* newconf->raid_disks already keeps a copy of * the increased
-	 * value of mddev->raid_disks, WARN_ONCE() is just used to make
-	 * sure of this. It is possible that oldconf is still referenced
-	 * in linear_congested(), therefore kfree_rcu() is used to free
-	 * oldconf until no one uses it anymore.
-	 */
-	mddev_suspend(mddev);
-	oldconf = rcu_dereference_protected(mddev->private,
-			lockdep_is_held(&mddev->reconfig_mutex));
-	mddev->raid_disks++;
-	WARN_ONCE(mddev->raid_disks != newconf->raid_disks,
-		"copied raid_disks doesn't match mddev->raid_disks");
-	rcu_assign_pointer(mddev->private, newconf);
-	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
-	set_capacity(mddev->gendisk, mddev->array_sectors);
-	mddev_resume(mddev);
-	revalidate_disk(mddev->gendisk);
-	kfree_rcu(oldconf, rcu);
-	return 0;
-}
-
-static void linear_free(struct mddev *mddev, void *priv)
-{
-	struct linear_conf *conf = priv;
-
-	kfree(conf);
-}
-
-static bool linear_make_request(struct mddev *mddev, struct bio *bio)
-{
-	char b[BDEVNAME_SIZE];
-	struct dev_info *tmp_dev;
-	sector_t start_sector, end_sector, data_offset;
-	sector_t bio_sector = bio->bi_iter.bi_sector;
-
-	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
-		md_flush_request(mddev, bio);
-		return true;
-	}
-
-	tmp_dev = which_dev(mddev, bio_sector);
-	start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
-	end_sector = tmp_dev->end_sector;
-	data_offset = tmp_dev->rdev->data_offset;
-
-	if (unlikely(bio_sector >= end_sector ||
-		     bio_sector < start_sector))
-		goto out_of_bounds;
-
-	if (unlikely(bio_end_sector(bio) > end_sector)) {
-		/* This bio crosses a device boundary, so we have to split it */
-		struct bio *split = bio_split(bio, end_sector - bio_sector,
-					      GFP_NOIO, mddev->bio_set);
-		bio_chain(split, bio);
-		generic_make_request(bio);
-		bio = split;
-	}
-
-	bio_set_dev(bio, tmp_dev->rdev->bdev);
-	bio->bi_iter.bi_sector = bio->bi_iter.bi_sector -
-		start_sector + data_offset;
-
-	if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
-		     !blk_queue_discard(bio->bi_disk->queue))) {
-		/* Just ignore it */
-		bio_endio(bio);
-	} else {
-		if (mddev->gendisk)
-			trace_block_bio_remap(bio->bi_disk->queue,
-					      bio, disk_devt(mddev->gendisk),
-					      bio_sector);
-		mddev_check_writesame(mddev, bio);
-		mddev_check_write_zeroes(mddev, bio);
-		generic_make_request(bio);
-	}
-	return true;
-
-out_of_bounds:
-	pr_err("md/linear:%s: make_request: Sector %llu out of bounds on dev %s: %llu sectors, offset %llu\n",
-	       mdname(mddev),
-	       (unsigned long long)bio->bi_iter.bi_sector,
-	       bdevname(tmp_dev->rdev->bdev, b),
-	       (unsigned long long)tmp_dev->rdev->sectors,
-	       (unsigned long long)start_sector);
-	bio_io_error(bio);
-	return true;
-}
-
-static void linear_status (struct seq_file *seq, struct mddev *mddev)
-{
-	seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
-}
-
-static void linear_quiesce(struct mddev *mddev, int state)
-{
-}
-
-static struct md_personality linear_personality =
-{
-	.name		= "linear",
-	.level		= LEVEL_LINEAR,
-	.owner		= THIS_MODULE,
-	.make_request	= linear_make_request,
-	.run		= linear_run,
-	.free		= linear_free,
-	.status		= linear_status,
-	.hot_add_disk	= linear_add,
-	.size		= linear_size,
-	.quiesce	= linear_quiesce,
-	.congested	= linear_congested,
-};
-
-static int __init linear_init (void)
-{
-	return register_md_personality (&linear_personality);
-}
-
-static void linear_exit (void)
-{
-	unregister_md_personality (&linear_personality);
-}
-
-module_init(linear_init);
-module_exit(linear_exit);
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Linear device concatenation personality for MD");
-MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
-MODULE_ALIAS("md-linear");
-MODULE_ALIAS("md-level--1");
--- a/drivers/md/linear.h
+++ /dev/null
@@ -1,16 +0,0 @@
-#ifndef _LINEAR_H
-#define _LINEAR_H
-
-struct dev_info {
-	struct md_rdev	*rdev;
-	sector_t	end_sector;
-};
-
-struct linear_conf
-{
-	struct rcu_head		rcu;
-	sector_t		array_sectors;
-	int			raid_disks; /* a copy of mddev->raid_disks */
-	struct dev_info		disks[0];
-};
-#endif
--- /dev/null
+++ b/drivers/md/md-bitmap.c
@@ -0,0 +1,2591 @@
+/*
+ * 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 "md-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, false);
+	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,
+};
+
--- /dev/null
+++ b/drivers/md/md-bitmap.h
@@ -0,0 +1,277 @@
+/*
+ * bitmap.h: Copyright (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
+ *
+ * additions: Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
+ */
+#ifndef BITMAP_H
+#define BITMAP_H 1
+
+#define BITMAP_MAJOR_LO 3
+/* version 4 insists the bitmap is in little-endian order
+ * with version 3, it is host-endian which is non-portable
+ * Version 5 is currently set only for clustered devices
+ */
+#define BITMAP_MAJOR_HI 4
+#define BITMAP_MAJOR_CLUSTERED 5
+#define	BITMAP_MAJOR_HOSTENDIAN 3
+
+/*
+ * in-memory bitmap:
+ *
+ * Use 16 bit block counters to track pending writes to each "chunk".
+ * The 2 high order bits are special-purpose, the first is a flag indicating
+ * whether a resync is needed.  The second is a flag indicating whether a
+ * resync is active.
+ * This means that the counter is actually 14 bits:
+ *
+ * +--------+--------+------------------------------------------------+
+ * | resync | resync |               counter                          |
+ * | needed | active |                                                |
+ * |  (0-1) |  (0-1) |              (0-16383)                         |
+ * +--------+--------+------------------------------------------------+
+ *
+ * The "resync needed" bit is set when:
+ *    a '1' bit is read from storage at startup.
+ *    a write request fails on some drives
+ *    a resync is aborted on a chunk with 'resync active' set
+ * It is cleared (and resync-active set) when a resync starts across all drives
+ * of the chunk.
+ *
+ *
+ * The "resync active" bit is set when:
+ *    a resync is started on all drives, and resync_needed is set.
+ *       resync_needed will be cleared (as long as resync_active wasn't already set).
+ * It is cleared when a resync completes.
+ *
+ * The counter counts pending write requests, plus the on-disk bit.
+ * When the counter is '1' and the resync bits are clear, the on-disk
+ * bit can be cleared as well, thus setting the counter to 0.
+ * When we set a bit, or in the counter (to start a write), if the fields is
+ * 0, we first set the disk bit and set the counter to 1.
+ *
+ * If the counter is 0, the on-disk bit is clear and the stripe is clean
+ * Anything that dirties the stripe pushes the counter to 2 (at least)
+ * and sets the on-disk bit (lazily).
+ * If a periodic sweep find the counter at 2, it is decremented to 1.
+ * If the sweep find the counter at 1, the on-disk bit is cleared and the
+ * counter goes to zero.
+ *
+ * Also, we'll hijack the "map" pointer itself and use it as two 16 bit block
+ * counters as a fallback when "page" memory cannot be allocated:
+ *
+ * Normal case (page memory allocated):
+ *
+ *     page pointer (32-bit)
+ *
+ *     [ ] ------+
+ *               |
+ *               +-------> [   ][   ]..[   ] (4096 byte page == 2048 counters)
+ *                          c1   c2    c2048
+ *
+ * Hijacked case (page memory allocation failed):
+ *
+ *     hijacked page pointer (32-bit)
+ *
+ *     [		  ][		  ] (no page memory allocated)
+ *      counter #1 (16-bit) counter #2 (16-bit)
+ *
+ */
+
+#ifdef __KERNEL__
+
+#define PAGE_BITS (PAGE_SIZE << 3)
+#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3)
+
+typedef __u16 bitmap_counter_t;
+#define COUNTER_BITS 16
+#define COUNTER_BIT_SHIFT 4
+#define COUNTER_BYTE_SHIFT (COUNTER_BIT_SHIFT - 3)
+
+#define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1)))
+#define RESYNC_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 2)))
+#define COUNTER_MAX ((bitmap_counter_t) RESYNC_MASK - 1)
+#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
+#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK)
+#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX)
+
+/* how many counters per page? */
+#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS)
+/* same, except a shift value for more efficient bitops */
+#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT)
+/* same, except a mask value for more efficient bitops */
+#define PAGE_COUNTER_MASK  (PAGE_COUNTER_RATIO - 1)
+
+#define BITMAP_BLOCK_SHIFT 9
+
+#endif
+
+/*
+ * bitmap structures:
+ */
+
+#define BITMAP_MAGIC 0x6d746962
+
+/* use these for bitmap->flags and bitmap->sb->state bit-fields */
+enum bitmap_state {
+	BITMAP_STALE	   = 1,  /* the bitmap file is out of date or had -EIO */
+	BITMAP_WRITE_ERROR = 2, /* A write error has occurred */
+	BITMAP_HOSTENDIAN  =15,
+};
+
+/* the superblock at the front of the bitmap file -- little endian */
+typedef struct bitmap_super_s {
+	__le32 magic;        /*  0  BITMAP_MAGIC */
+	__le32 version;      /*  4  the bitmap major for now, could change... */
+	__u8  uuid[16];      /*  8  128 bit uuid - must match md device uuid */
+	__le64 events;       /* 24  event counter for the bitmap (1)*/
+	__le64 events_cleared;/*32  event counter when last bit cleared (2) */
+	__le64 sync_size;    /* 40  the size of the md device's sync range(3) */
+	__le32 state;        /* 48  bitmap state information */
+	__le32 chunksize;    /* 52  the bitmap chunk size in bytes */
+	__le32 daemon_sleep; /* 56  seconds between disk flushes */
+	__le32 write_behind; /* 60  number of outstanding write-behind writes */
+	__le32 sectors_reserved; /* 64 number of 512-byte sectors that are
+				  * reserved for the bitmap. */
+	__le32 nodes;        /* 68 the maximum number of nodes in cluster. */
+	__u8 cluster_name[64]; /* 72 cluster name to which this md belongs */
+	__u8  pad[256 - 136]; /* set to zero */
+} bitmap_super_t;
+
+/* notes:
+ * (1) This event counter is updated before the eventcounter in the md superblock
+ *    When a bitmap is loaded, it is only accepted if this event counter is equal
+ *    to, or one greater than, the event counter in the superblock.
+ * (2) This event counter is updated when the other one is *if*and*only*if* the
+ *    array is not degraded.  As bits are not cleared when the array is degraded,
+ *    this represents the last time that any bits were cleared.
+ *    If a device is being added that has an event count with this value or
+ *    higher, it is accepted as conforming to the bitmap.
+ * (3)This is the number of sectors represented by the bitmap, and is the range that
+ *    resync happens across.  For raid1 and raid5/6 it is the size of individual
+ *    devices.  For raid10 it is the size of the array.
+ */
+
+#ifdef __KERNEL__
+
+/* the in-memory bitmap is represented by bitmap_pages */
+struct bitmap_page {
+	/*
+	 * map points to the actual memory page
+	 */
+	char *map;
+	/*
+	 * in emergencies (when map cannot be alloced), hijack the map
+	 * pointer and use it as two counters itself
+	 */
+	unsigned int hijacked:1;
+	/*
+	 * If any counter in this page is '1' or '2' - and so could be
+	 * cleared then that page is marked as 'pending'
+	 */
+	unsigned int pending:1;
+	/*
+	 * count of dirty bits on the page
+	 */
+	unsigned int  count:30;
+};
+
+/* the main bitmap structure - one per mddev */
+struct bitmap {
+
+	struct bitmap_counts {
+		spinlock_t lock;
+		struct bitmap_page *bp;
+		unsigned long pages;		/* total number of pages
+						 * in the bitmap */
+		unsigned long missing_pages;	/* number of pages
+						 * not yet allocated */
+		unsigned long chunkshift;	/* chunksize = 2^chunkshift
+						 * (for bitops) */
+		unsigned long chunks;		/* Total number of data
+						 * chunks for the array */
+	} counts;
+
+	struct mddev *mddev; /* the md device that the bitmap is for */
+
+	__u64	events_cleared;
+	int need_sync;
+
+	struct bitmap_storage {
+		struct file *file;		/* backing disk file */
+		struct page *sb_page;		/* cached copy of the bitmap
+						 * file superblock */
+		struct page **filemap;		/* list of cache pages for
+						 * the file */
+		unsigned long *filemap_attr;	/* attributes associated
+						 * w/ filemap pages */
+		unsigned long file_pages;	/* number of pages in the file*/
+		unsigned long bytes;		/* total bytes in the bitmap */
+	} storage;
+
+	unsigned long flags;
+
+	int allclean;
+
+	atomic_t behind_writes;
+	unsigned long behind_writes_used; /* highest actual value at runtime */
+
+	/*
+	 * the bitmap daemon - periodically wakes up and sweeps the bitmap
+	 * file, cleaning up bits and flushing out pages to disk as necessary
+	 */
+	unsigned long daemon_lastrun; /* jiffies of last run */
+	unsigned long last_end_sync; /* when we lasted called end_sync to
+				      * update bitmap with resync progress */
+
+	atomic_t pending_writes; /* pending writes to the bitmap file */
+	wait_queue_head_t write_wait;
+	wait_queue_head_t overflow_wait;
+	wait_queue_head_t behind_wait;
+
+	struct kernfs_node *sysfs_can_clear;
+	int cluster_slot;		/* Slot offset for clustered env */
+};
+
+/* the bitmap API */
+
+/* these are used only by md/bitmap */
+struct bitmap *bitmap_create(struct mddev *mddev, int slot);
+int bitmap_load(struct mddev *mddev);
+void bitmap_flush(struct mddev *mddev);
+void bitmap_destroy(struct mddev *mddev);
+
+void bitmap_print_sb(struct bitmap *bitmap);
+void bitmap_update_sb(struct bitmap *bitmap);
+void bitmap_status(struct seq_file *seq, struct bitmap *bitmap);
+
+int  bitmap_setallbits(struct bitmap *bitmap);
+void bitmap_write_all(struct bitmap *bitmap);
+
+void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e);
+
+/* these are exported */
+int bitmap_startwrite(struct bitmap *bitmap, sector_t offset,
+			unsigned long sectors, int behind);
+void bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
+			unsigned long sectors, int success, int behind);
+int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int degraded);
+void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted);
+void bitmap_close_sync(struct bitmap *bitmap);
+void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force);
+void bitmap_sync_with_cluster(struct mddev *mddev,
+			      sector_t old_lo, sector_t old_hi,
+			      sector_t new_lo, sector_t new_hi);
+
+void bitmap_unplug(struct bitmap *bitmap);
+void bitmap_daemon_work(struct mddev *mddev);
+
+int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
+		  int chunksize, int init);
+struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot);
+int bitmap_copy_from_slot(struct mddev *mddev, int slot,
+				sector_t *lo, sector_t *hi, bool clear_bits);
+void bitmap_free(struct bitmap *bitmap);
+void bitmap_wait_behind_writes(struct mddev *mddev);
+#endif
+
+#endif
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -15,7 +15,7 @@
 #include <linux/sched.h>
 #include <linux/raid/md_p.h>
 #include "md.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 #include "md-cluster.h"
 
 #define LVB_SIZE	64
--- /dev/null
+++ b/drivers/md/md-faulty.c
@@ -0,0 +1,372 @@
+/*
+ * faulty.c : Multiple Devices driver for Linux
+ *
+ * Copyright (C) 2004 Neil Brown
+ *
+ * fautly-device-simulator personality for md
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+/*
+ * The "faulty" personality causes some requests to fail.
+ *
+ * Possible failure modes are:
+ *   reads fail "randomly" but succeed on retry
+ *   writes fail "randomly" but succeed on retry
+ *   reads for some address fail and then persist until a write
+ *   reads for some address fail and then persist irrespective of write
+ *   writes for some address fail and persist
+ *   all writes fail
+ *
+ * Different modes can be active at a time, but only
+ * one can be set at array creation.  Others can be added later.
+ * A mode can be one-shot or recurrent with the recurrence being
+ * once in every N requests.
+ * The bottom 5 bits of the "layout" indicate the mode.  The
+ * remainder indicate a period, or 0 for one-shot.
+ *
+ * There is an implementation limit on the number of concurrently
+ * persisting-faulty blocks. When a new fault is requested that would
+ * exceed the limit, it is ignored.
+ * All current faults can be clear using a layout of "0".
+ *
+ * Requests are always sent to the device.  If they are to fail,
+ * we clone the bio and insert a new b_end_io into the chain.
+ */
+
+#define	WriteTransient	0
+#define	ReadTransient	1
+#define	WritePersistent	2
+#define	ReadPersistent	3
+#define	WriteAll	4 /* doesn't go to device */
+#define	ReadFixable	5
+#define	Modes	6
+
+#define	ClearErrors	31
+#define	ClearFaults	30
+
+#define AllPersist	100 /* internal use only */
+#define	NoPersist	101
+
+#define	ModeMask	0x1f
+#define	ModeShift	5
+
+#define MaxFault	50
+#include <linux/blkdev.h>
+#include <linux/module.h>
+#include <linux/raid/md_u.h>
+#include <linux/slab.h>
+#include "md.h"
+#include <linux/seq_file.h>
+
+
+static void faulty_fail(struct bio *bio)
+{
+	struct bio *b = bio->bi_private;
+
+	b->bi_iter.bi_size = bio->bi_iter.bi_size;
+	b->bi_iter.bi_sector = bio->bi_iter.bi_sector;
+
+	bio_put(bio);
+
+	bio_io_error(b);
+}
+
+struct faulty_conf {
+	int period[Modes];
+	atomic_t counters[Modes];
+	sector_t faults[MaxFault];
+	int	modes[MaxFault];
+	int nfaults;
+	struct md_rdev *rdev;
+};
+
+static int check_mode(struct faulty_conf *conf, int mode)
+{
+	if (conf->period[mode] == 0 &&
+	    atomic_read(&conf->counters[mode]) <= 0)
+		return 0; /* no failure, no decrement */
+
+
+	if (atomic_dec_and_test(&conf->counters[mode])) {
+		if (conf->period[mode])
+			atomic_set(&conf->counters[mode], conf->period[mode]);
+		return 1;
+	}
+	return 0;
+}
+
+static int check_sector(struct faulty_conf *conf, sector_t start, sector_t end, int dir)
+{
+	/* If we find a ReadFixable sector, we fix it ... */
+	int i;
+	for (i=0; i<conf->nfaults; i++)
+		if (conf->faults[i] >= start &&
+		    conf->faults[i] < end) {
+			/* found it ... */
+			switch (conf->modes[i] * 2 + dir) {
+			case WritePersistent*2+WRITE: return 1;
+			case ReadPersistent*2+READ: return 1;
+			case ReadFixable*2+READ: return 1;
+			case ReadFixable*2+WRITE:
+				conf->modes[i] = NoPersist;
+				return 0;
+			case AllPersist*2+READ:
+			case AllPersist*2+WRITE: return 1;
+			default:
+				return 0;
+			}
+		}
+	return 0;
+}
+
+static void add_sector(struct faulty_conf *conf, sector_t start, int mode)
+{
+	int i;
+	int n = conf->nfaults;
+	for (i=0; i<conf->nfaults; i++)
+		if (conf->faults[i] == start) {
+			switch(mode) {
+			case NoPersist: conf->modes[i] = mode; return;
+			case WritePersistent:
+				if (conf->modes[i] == ReadPersistent ||
+				    conf->modes[i] == ReadFixable)
+					conf->modes[i] = AllPersist;
+				else
+					conf->modes[i] = WritePersistent;
+				return;
+			case ReadPersistent:
+				if (conf->modes[i] == WritePersistent)
+					conf->modes[i] = AllPersist;
+				else
+					conf->modes[i] = ReadPersistent;
+				return;
+			case ReadFixable:
+				if (conf->modes[i] == WritePersistent ||
+				    conf->modes[i] == ReadPersistent)
+					conf->modes[i] = AllPersist;
+				else
+					conf->modes[i] = ReadFixable;
+				return;
+			}
+		} else if (conf->modes[i] == NoPersist)
+			n = i;
+
+	if (n >= MaxFault)
+		return;
+	conf->faults[n] = start;
+	conf->modes[n] = mode;
+	if (conf->nfaults == n)
+		conf->nfaults = n+1;
+}
+
+static bool faulty_make_request(struct mddev *mddev, struct bio *bio)
+{
+	struct faulty_conf *conf = mddev->private;
+	int failit = 0;
+
+	if (bio_data_dir(bio) == WRITE) {
+		/* write request */
+		if (atomic_read(&conf->counters[WriteAll])) {
+			/* special case - don't decrement, don't generic_make_request,
+			 * just fail immediately
+			 */
+			bio_io_error(bio);
+			return true;
+		}
+
+		if (check_sector(conf, bio->bi_iter.bi_sector,
+				 bio_end_sector(bio), WRITE))
+			failit = 1;
+		if (check_mode(conf, WritePersistent)) {
+			add_sector(conf, bio->bi_iter.bi_sector,
+				   WritePersistent);
+			failit = 1;
+		}
+		if (check_mode(conf, WriteTransient))
+			failit = 1;
+	} else {
+		/* read request */
+		if (check_sector(conf, bio->bi_iter.bi_sector,
+				 bio_end_sector(bio), READ))
+			failit = 1;
+		if (check_mode(conf, ReadTransient))
+			failit = 1;
+		if (check_mode(conf, ReadPersistent)) {
+			add_sector(conf, bio->bi_iter.bi_sector,
+				   ReadPersistent);
+			failit = 1;
+		}
+		if (check_mode(conf, ReadFixable)) {
+			add_sector(conf, bio->bi_iter.bi_sector,
+				   ReadFixable);
+			failit = 1;
+		}
+	}
+	if (failit) {
+		struct bio *b = bio_clone_fast(bio, GFP_NOIO, mddev->bio_set);
+
+		bio_set_dev(b, conf->rdev->bdev);
+		b->bi_private = bio;
+		b->bi_end_io = faulty_fail;
+		bio = b;
+	} else
+		bio_set_dev(bio, conf->rdev->bdev);
+
+	generic_make_request(bio);
+	return true;
+}
+
+static void faulty_status(struct seq_file *seq, struct mddev *mddev)
+{
+	struct faulty_conf *conf = mddev->private;
+	int n;
+
+	if ((n=atomic_read(&conf->counters[WriteTransient])) != 0)
+		seq_printf(seq, " WriteTransient=%d(%d)",
+			   n, conf->period[WriteTransient]);
+
+	if ((n=atomic_read(&conf->counters[ReadTransient])) != 0)
+		seq_printf(seq, " ReadTransient=%d(%d)",
+			   n, conf->period[ReadTransient]);
+
+	if ((n=atomic_read(&conf->counters[WritePersistent])) != 0)
+		seq_printf(seq, " WritePersistent=%d(%d)",
+			   n, conf->period[WritePersistent]);
+
+	if ((n=atomic_read(&conf->counters[ReadPersistent])) != 0)
+		seq_printf(seq, " ReadPersistent=%d(%d)",
+			   n, conf->period[ReadPersistent]);
+
+
+	if ((n=atomic_read(&conf->counters[ReadFixable])) != 0)
+		seq_printf(seq, " ReadFixable=%d(%d)",
+			   n, conf->period[ReadFixable]);
+
+	if ((n=atomic_read(&conf->counters[WriteAll])) != 0)
+		seq_printf(seq, " WriteAll");
+
+	seq_printf(seq, " nfaults=%d", conf->nfaults);
+}
+
+
+static int faulty_reshape(struct mddev *mddev)
+{
+	int mode = mddev->new_layout & ModeMask;
+	int count = mddev->new_layout >> ModeShift;
+	struct faulty_conf *conf = mddev->private;
+
+	if (mddev->new_layout < 0)
+		return 0;
+
+	/* new layout */
+	if (mode == ClearFaults)
+		conf->nfaults = 0;
+	else if (mode == ClearErrors) {
+		int i;
+		for (i=0 ; i < Modes ; i++) {
+			conf->period[i] = 0;
+			atomic_set(&conf->counters[i], 0);
+		}
+	} else if (mode < Modes) {
+		conf->period[mode] = count;
+		if (!count) count++;
+		atomic_set(&conf->counters[mode], count);
+	} else
+		return -EINVAL;
+	mddev->new_layout = -1;
+	mddev->layout = -1; /* makes sure further changes come through */
+	return 0;
+}
+
+static sector_t faulty_size(struct mddev *mddev, sector_t sectors, int raid_disks)
+{
+	WARN_ONCE(raid_disks,
+		  "%s does not support generic reshape\n", __func__);
+
+	if (sectors == 0)
+		return mddev->dev_sectors;
+
+	return sectors;
+}
+
+static int faulty_run(struct mddev *mddev)
+{
+	struct md_rdev *rdev;
+	int i;
+	struct faulty_conf *conf;
+
+	if (md_check_no_bitmap(mddev))
+		return -EINVAL;
+
+	conf = kmalloc(sizeof(*conf), GFP_KERNEL);
+	if (!conf)
+		return -ENOMEM;
+
+	for (i=0; i<Modes; i++) {
+		atomic_set(&conf->counters[i], 0);
+		conf->period[i] = 0;
+	}
+	conf->nfaults = 0;
+
+	rdev_for_each(rdev, mddev) {
+		conf->rdev = rdev;
+		disk_stack_limits(mddev->gendisk, rdev->bdev,
+				  rdev->data_offset << 9);
+	}
+
+	md_set_array_sectors(mddev, faulty_size(mddev, 0, 0));
+	mddev->private = conf;
+
+	faulty_reshape(mddev);
+
+	return 0;
+}
+
+static void faulty_free(struct mddev *mddev, void *priv)
+{
+	struct faulty_conf *conf = priv;
+
+	kfree(conf);
+}
+
+static struct md_personality faulty_personality =
+{
+	.name		= "faulty",
+	.level		= LEVEL_FAULTY,
+	.owner		= THIS_MODULE,
+	.make_request	= faulty_make_request,
+	.run		= faulty_run,
+	.free		= faulty_free,
+	.status		= faulty_status,
+	.check_reshape	= faulty_reshape,
+	.size		= faulty_size,
+};
+
+static int __init raid_init(void)
+{
+	return register_md_personality(&faulty_personality);
+}
+
+static void raid_exit(void)
+{
+	unregister_md_personality(&faulty_personality);
+}
+
+module_init(raid_init);
+module_exit(raid_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Fault injection personality for MD");
+MODULE_ALIAS("md-personality-10"); /* faulty */
+MODULE_ALIAS("md-faulty");
+MODULE_ALIAS("md-level--5");
--- /dev/null
+++ b/drivers/md/md-linear.c
@@ -0,0 +1,348 @@
+/*
+   linear.c : Multiple Devices driver for Linux
+	      Copyright (C) 1994-96 Marc ZYNGIER
+	      <zyngier@ufr-info-p7.ibp.fr> or
+	      <maz@gloups.fdn.fr>
+
+   Linear mode management functions.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   You should have received a copy of the GNU General Public License
+   (for example /usr/src/linux/COPYING); if not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <linux/blkdev.h>
+#include <linux/raid/md_u.h>
+#include <linux/seq_file.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <trace/events/block.h>
+#include "md.h"
+#include "md-linear.h"
+
+/*
+ * find which device holds a particular offset
+ */
+static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector)
+{
+	int lo, mid, hi;
+	struct linear_conf *conf;
+
+	lo = 0;
+	hi = mddev->raid_disks - 1;
+	conf = mddev->private;
+
+	/*
+	 * Binary Search
+	 */
+
+	while (hi > lo) {
+
+		mid = (hi + lo) / 2;
+		if (sector < conf->disks[mid].end_sector)
+			hi = mid;
+		else
+			lo = mid + 1;
+	}
+
+	return conf->disks + lo;
+}
+
+/*
+ * In linear_congested() conf->raid_disks is used as a copy of
+ * mddev->raid_disks to iterate conf->disks[], because conf->raid_disks
+ * and conf->disks[] are created in linear_conf(), they are always
+ * consitent with each other, but mddev->raid_disks does not.
+ */
+static int linear_congested(struct mddev *mddev, int bits)
+{
+	struct linear_conf *conf;
+	int i, ret = 0;
+
+	rcu_read_lock();
+	conf = rcu_dereference(mddev->private);
+
+	for (i = 0; i < conf->raid_disks && !ret ; i++) {
+		struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev);
+		ret |= bdi_congested(q->backing_dev_info, bits);
+	}
+
+	rcu_read_unlock();
+	return ret;
+}
+
+static sector_t linear_size(struct mddev *mddev, sector_t sectors, int raid_disks)
+{
+	struct linear_conf *conf;
+	sector_t array_sectors;
+
+	conf = mddev->private;
+	WARN_ONCE(sectors || raid_disks,
+		  "%s does not support generic reshape\n", __func__);
+	array_sectors = conf->array_sectors;
+
+	return array_sectors;
+}
+
+static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
+{
+	struct linear_conf *conf;
+	struct md_rdev *rdev;
+	int i, cnt;
+	bool discard_supported = false;
+
+	conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
+			GFP_KERNEL);
+	if (!conf)
+		return NULL;
+
+	cnt = 0;
+	conf->array_sectors = 0;
+
+	rdev_for_each(rdev, mddev) {
+		int j = rdev->raid_disk;
+		struct dev_info *disk = conf->disks + j;
+		sector_t sectors;
+
+		if (j < 0 || j >= raid_disks || disk->rdev) {
+			pr_warn("md/linear:%s: disk numbering problem. Aborting!\n",
+				mdname(mddev));
+			goto out;
+		}
+
+		disk->rdev = rdev;
+		if (mddev->chunk_sectors) {
+			sectors = rdev->sectors;
+			sector_div(sectors, mddev->chunk_sectors);
+			rdev->sectors = sectors * mddev->chunk_sectors;
+		}
+
+		disk_stack_limits(mddev->gendisk, rdev->bdev,
+				  rdev->data_offset << 9);
+
+		conf->array_sectors += rdev->sectors;
+		cnt++;
+
+		if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+			discard_supported = true;
+	}
+	if (cnt != raid_disks) {
+		pr_warn("md/linear:%s: not enough drives present. Aborting!\n",
+			mdname(mddev));
+		goto out;
+	}
+
+	if (!discard_supported)
+		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+	else
+		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+
+	/*
+	 * Here we calculate the device offsets.
+	 */
+	conf->disks[0].end_sector = conf->disks[0].rdev->sectors;
+
+	for (i = 1; i < raid_disks; i++)
+		conf->disks[i].end_sector =
+			conf->disks[i-1].end_sector +
+			conf->disks[i].rdev->sectors;
+
+	/*
+	 * conf->raid_disks is copy of mddev->raid_disks. The reason to
+	 * keep a copy of mddev->raid_disks in struct linear_conf is,
+	 * mddev->raid_disks may not be consistent with pointers number of
+	 * conf->disks[] when it is updated in linear_add() and used to
+	 * iterate old conf->disks[] earray in linear_congested().
+	 * Here conf->raid_disks is always consitent with number of
+	 * pointers in conf->disks[] array, and mddev->private is updated
+	 * with rcu_assign_pointer() in linear_addr(), such race can be
+	 * avoided.
+	 */
+	conf->raid_disks = raid_disks;
+
+	return conf;
+
+out:
+	kfree(conf);
+	return NULL;
+}
+
+static int linear_run (struct mddev *mddev)
+{
+	struct linear_conf *conf;
+	int ret;
+
+	if (md_check_no_bitmap(mddev))
+		return -EINVAL;
+	conf = linear_conf(mddev, mddev->raid_disks);
+
+	if (!conf)
+		return 1;
+	mddev->private = conf;
+	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
+
+	ret =  md_integrity_register(mddev);
+	if (ret) {
+		kfree(conf);
+		mddev->private = NULL;
+	}
+	return ret;
+}
+
+static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
+{
+	/* Adding a drive to a linear array allows the array to grow.
+	 * It is permitted if the new drive has a matching superblock
+	 * already on it, with raid_disk equal to raid_disks.
+	 * It is achieved by creating a new linear_private_data structure
+	 * and swapping it in in-place of the current one.
+	 * The current one is never freed until the array is stopped.
+	 * This avoids races.
+	 */
+	struct linear_conf *newconf, *oldconf;
+
+	if (rdev->saved_raid_disk != mddev->raid_disks)
+		return -EINVAL;
+
+	rdev->raid_disk = rdev->saved_raid_disk;
+	rdev->saved_raid_disk = -1;
+
+	newconf = linear_conf(mddev,mddev->raid_disks+1);
+
+	if (!newconf)
+		return -ENOMEM;
+
+	/* newconf->raid_disks already keeps a copy of * the increased
+	 * value of mddev->raid_disks, WARN_ONCE() is just used to make
+	 * sure of this. It is possible that oldconf is still referenced
+	 * in linear_congested(), therefore kfree_rcu() is used to free
+	 * oldconf until no one uses it anymore.
+	 */
+	mddev_suspend(mddev);
+	oldconf = rcu_dereference_protected(mddev->private,
+			lockdep_is_held(&mddev->reconfig_mutex));
+	mddev->raid_disks++;
+	WARN_ONCE(mddev->raid_disks != newconf->raid_disks,
+		"copied raid_disks doesn't match mddev->raid_disks");
+	rcu_assign_pointer(mddev->private, newconf);
+	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
+	set_capacity(mddev->gendisk, mddev->array_sectors);
+	mddev_resume(mddev);
+	revalidate_disk(mddev->gendisk);
+	kfree_rcu(oldconf, rcu);
+	return 0;
+}
+
+static void linear_free(struct mddev *mddev, void *priv)
+{
+	struct linear_conf *conf = priv;
+
+	kfree(conf);
+}
+
+static bool linear_make_request(struct mddev *mddev, struct bio *bio)
+{
+	char b[BDEVNAME_SIZE];
+	struct dev_info *tmp_dev;
+	sector_t start_sector, end_sector, data_offset;
+	sector_t bio_sector = bio->bi_iter.bi_sector;
+
+	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
+		md_flush_request(mddev, bio);
+		return true;
+	}
+
+	tmp_dev = which_dev(mddev, bio_sector);
+	start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
+	end_sector = tmp_dev->end_sector;
+	data_offset = tmp_dev->rdev->data_offset;
+
+	if (unlikely(bio_sector >= end_sector ||
+		     bio_sector < start_sector))
+		goto out_of_bounds;
+
+	if (unlikely(bio_end_sector(bio) > end_sector)) {
+		/* This bio crosses a device boundary, so we have to split it */
+		struct bio *split = bio_split(bio, end_sector - bio_sector,
+					      GFP_NOIO, mddev->bio_set);
+		bio_chain(split, bio);
+		generic_make_request(bio);
+		bio = split;
+	}
+
+	bio_set_dev(bio, tmp_dev->rdev->bdev);
+	bio->bi_iter.bi_sector = bio->bi_iter.bi_sector -
+		start_sector + data_offset;
+
+	if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
+		     !blk_queue_discard(bio->bi_disk->queue))) {
+		/* Just ignore it */
+		bio_endio(bio);
+	} else {
+		if (mddev->gendisk)
+			trace_block_bio_remap(bio->bi_disk->queue,
+					      bio, disk_devt(mddev->gendisk),
+					      bio_sector);
+		mddev_check_writesame(mddev, bio);
+		mddev_check_write_zeroes(mddev, bio);
+		generic_make_request(bio);
+	}
+	return true;
+
+out_of_bounds:
+	pr_err("md/linear:%s: make_request: Sector %llu out of bounds on dev %s: %llu sectors, offset %llu\n",
+	       mdname(mddev),
+	       (unsigned long long)bio->bi_iter.bi_sector,
+	       bdevname(tmp_dev->rdev->bdev, b),
+	       (unsigned long long)tmp_dev->rdev->sectors,
+	       (unsigned long long)start_sector);
+	bio_io_error(bio);
+	return true;
+}
+
+static void linear_status (struct seq_file *seq, struct mddev *mddev)
+{
+	seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
+}
+
+static void linear_quiesce(struct mddev *mddev, int state)
+{
+}
+
+static struct md_personality linear_personality =
+{
+	.name		= "linear",
+	.level		= LEVEL_LINEAR,
+	.owner		= THIS_MODULE,
+	.make_request	= linear_make_request,
+	.run		= linear_run,
+	.free		= linear_free,
+	.status		= linear_status,
+	.hot_add_disk	= linear_add,
+	.size		= linear_size,
+	.quiesce	= linear_quiesce,
+	.congested	= linear_congested,
+};
+
+static int __init linear_init (void)
+{
+	return register_md_personality (&linear_personality);
+}
+
+static void linear_exit (void)
+{
+	unregister_md_personality (&linear_personality);
+}
+
+module_init(linear_init);
+module_exit(linear_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Linear device concatenation personality for MD");
+MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
+MODULE_ALIAS("md-linear");
+MODULE_ALIAS("md-level--1");
--- /dev/null
+++ b/drivers/md/md-linear.h
@@ -0,0 +1,16 @@
+#ifndef _LINEAR_H
+#define _LINEAR_H
+
+struct dev_info {
+	struct md_rdev	*rdev;
+	sector_t	end_sector;
+};
+
+struct linear_conf
+{
+	struct rcu_head		rcu;
+	sector_t		array_sectors;
+	int			raid_disks; /* a copy of mddev->raid_disks */
+	struct dev_info		disks[0];
+};
+#endif
--- /dev/null
+++ b/drivers/md/md-multipath.c
@@ -0,0 +1,509 @@
+/*
+ * multipath.c : Multiple Devices driver for Linux
+ *
+ * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
+ *
+ * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
+ *
+ * MULTIPATH management functions.
+ *
+ * derived from raid1.c.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/module.h>
+#include <linux/raid/md_u.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include "md.h"
+#include "md-multipath.h"
+
+#define MAX_WORK_PER_DISK 128
+
+#define	NR_RESERVED_BUFS	32
+
+static int multipath_map (struct mpconf *conf)
+{
+	int i, disks = conf->raid_disks;
+
+	/*
+	 * Later we do read balancing on the read side
+	 * now we use the first available disk.
+	 */
+
+	rcu_read_lock();
+	for (i = 0; i < disks; i++) {
+		struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
+		if (rdev && test_bit(In_sync, &rdev->flags) &&
+		    !test_bit(Faulty, &rdev->flags)) {
+			atomic_inc(&rdev->nr_pending);
+			rcu_read_unlock();
+			return i;
+		}
+	}
+	rcu_read_unlock();
+
+	pr_crit_ratelimited("multipath_map(): no more operational IO paths?\n");
+	return (-1);
+}
+
+static void multipath_reschedule_retry (struct multipath_bh *mp_bh)
+{
+	unsigned long flags;
+	struct mddev *mddev = mp_bh->mddev;
+	struct mpconf *conf = mddev->private;
+
+	spin_lock_irqsave(&conf->device_lock, flags);
+	list_add(&mp_bh->retry_list, &conf->retry_list);
+	spin_unlock_irqrestore(&conf->device_lock, flags);
+	md_wakeup_thread(mddev->thread);
+}
+
+/*
+ * multipath_end_bh_io() is called when we have finished servicing a multipathed
+ * operation and are ready to return a success/failure code to the buffer
+ * cache layer.
+ */
+static void multipath_end_bh_io(struct multipath_bh *mp_bh, blk_status_t status)
+{
+	struct bio *bio = mp_bh->master_bio;
+	struct mpconf *conf = mp_bh->mddev->private;
+
+	bio->bi_status = status;
+	bio_endio(bio);
+	mempool_free(mp_bh, conf->pool);
+}
+
+static void multipath_end_request(struct bio *bio)
+{
+	struct multipath_bh *mp_bh = bio->bi_private;
+	struct mpconf *conf = mp_bh->mddev->private;
+	struct md_rdev *rdev = conf->multipaths[mp_bh->path].rdev;
+
+	if (!bio->bi_status)
+		multipath_end_bh_io(mp_bh, 0);
+	else if (!(bio->bi_opf & REQ_RAHEAD)) {
+		/*
+		 * oops, IO error:
+		 */
+		char b[BDEVNAME_SIZE];
+		md_error (mp_bh->mddev, rdev);
+		pr_info("multipath: %s: rescheduling sector %llu\n",
+			bdevname(rdev->bdev,b),
+			(unsigned long long)bio->bi_iter.bi_sector);
+		multipath_reschedule_retry(mp_bh);
+	} else
+		multipath_end_bh_io(mp_bh, bio->bi_status);
+	rdev_dec_pending(rdev, conf->mddev);
+}
+
+static bool multipath_make_request(struct mddev *mddev, struct bio * bio)
+{
+	struct mpconf *conf = mddev->private;
+	struct multipath_bh * mp_bh;
+	struct multipath_info *multipath;
+
+	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
+		md_flush_request(mddev, bio);
+		return true;
+	}
+
+	mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
+
+	mp_bh->master_bio = bio;
+	mp_bh->mddev = mddev;
+
+	mp_bh->path = multipath_map(conf);
+	if (mp_bh->path < 0) {
+		bio_io_error(bio);
+		mempool_free(mp_bh, conf->pool);
+		return true;
+	}
+	multipath = conf->multipaths + mp_bh->path;
+
+	bio_init(&mp_bh->bio, NULL, 0);
+	__bio_clone_fast(&mp_bh->bio, bio);
+
+	mp_bh->bio.bi_iter.bi_sector += multipath->rdev->data_offset;
+	bio_set_dev(&mp_bh->bio, multipath->rdev->bdev);
+	mp_bh->bio.bi_opf |= REQ_FAILFAST_TRANSPORT;
+	mp_bh->bio.bi_end_io = multipath_end_request;
+	mp_bh->bio.bi_private = mp_bh;
+	mddev_check_writesame(mddev, &mp_bh->bio);
+	mddev_check_write_zeroes(mddev, &mp_bh->bio);
+	generic_make_request(&mp_bh->bio);
+	return true;
+}
+
+static void multipath_status(struct seq_file *seq, struct mddev *mddev)
+{
+	struct mpconf *conf = mddev->private;
+	int i;
+
+	seq_printf (seq, " [%d/%d] [", conf->raid_disks,
+		    conf->raid_disks - mddev->degraded);
+	rcu_read_lock();
+	for (i = 0; i < conf->raid_disks; i++) {
+		struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
+		seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+	}
+	rcu_read_unlock();
+	seq_printf (seq, "]");
+}
+
+static int multipath_congested(struct mddev *mddev, int bits)
+{
+	struct mpconf *conf = mddev->private;
+	int i, ret = 0;
+
+	rcu_read_lock();
+	for (i = 0; i < mddev->raid_disks ; i++) {
+		struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
+		if (rdev && !test_bit(Faulty, &rdev->flags)) {
+			struct request_queue *q = bdev_get_queue(rdev->bdev);
+
+			ret |= bdi_congested(q->backing_dev_info, bits);
+			/* Just like multipath_map, we just check the
+			 * first available device
+			 */
+			break;
+		}
+	}
+	rcu_read_unlock();
+	return ret;
+}
+
+/*
+ * Careful, this can execute in IRQ contexts as well!
+ */
+static void multipath_error (struct mddev *mddev, struct md_rdev *rdev)
+{
+	struct mpconf *conf = mddev->private;
+	char b[BDEVNAME_SIZE];
+
+	if (conf->raid_disks - mddev->degraded <= 1) {
+		/*
+		 * Uh oh, we can do nothing if this is our last path, but
+		 * first check if this is a queued request for a device
+		 * which has just failed.
+		 */
+		pr_warn("multipath: only one IO path left and IO error.\n");
+		/* leave it active... it's all we have */
+		return;
+	}
+	/*
+	 * Mark disk as unusable
+	 */
+	if (test_and_clear_bit(In_sync, &rdev->flags)) {
+		unsigned long flags;
+		spin_lock_irqsave(&conf->device_lock, flags);
+		mddev->degraded++;
+		spin_unlock_irqrestore(&conf->device_lock, flags);
+	}
+	set_bit(Faulty, &rdev->flags);
+	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
+	pr_err("multipath: IO failure on %s, disabling IO path.\n"
+	       "multipath: Operation continuing on %d IO paths.\n",
+	       bdevname(rdev->bdev, b),
+	       conf->raid_disks - mddev->degraded);
+}
+
+static void print_multipath_conf (struct mpconf *conf)
+{
+	int i;
+	struct multipath_info *tmp;
+
+	pr_debug("MULTIPATH conf printout:\n");
+	if (!conf) {
+		pr_debug("(conf==NULL)\n");
+		return;
+	}
+	pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
+		 conf->raid_disks);
+
+	for (i = 0; i < conf->raid_disks; i++) {
+		char b[BDEVNAME_SIZE];
+		tmp = conf->multipaths + i;
+		if (tmp->rdev)
+			pr_debug(" disk%d, o:%d, dev:%s\n",
+				 i,!test_bit(Faulty, &tmp->rdev->flags),
+				 bdevname(tmp->rdev->bdev,b));
+	}
+}
+
+static int multipath_add_disk(struct mddev *mddev, struct md_rdev *rdev)
+{
+	struct mpconf *conf = mddev->private;
+	struct request_queue *q;
+	int err = -EEXIST;
+	int path;
+	struct multipath_info *p;
+	int first = 0;
+	int last = mddev->raid_disks - 1;
+
+	if (rdev->raid_disk >= 0)
+		first = last = rdev->raid_disk;
+
+	print_multipath_conf(conf);
+
+	for (path = first; path <= last; path++)
+		if ((p=conf->multipaths+path)->rdev == NULL) {
+			q = rdev->bdev->bd_disk->queue;
+			disk_stack_limits(mddev->gendisk, rdev->bdev,
+					  rdev->data_offset << 9);
+
+			err = md_integrity_add_rdev(rdev, mddev);
+			if (err)
+				break;
+			spin_lock_irq(&conf->device_lock);
+			mddev->degraded--;
+			rdev->raid_disk = path;
+			set_bit(In_sync, &rdev->flags);
+			spin_unlock_irq(&conf->device_lock);
+			rcu_assign_pointer(p->rdev, rdev);
+			err = 0;
+			break;
+		}
+
+	print_multipath_conf(conf);
+
+	return err;
+}
+
+static int multipath_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
+{
+	struct mpconf *conf = mddev->private;
+	int err = 0;
+	int number = rdev->raid_disk;
+	struct multipath_info *p = conf->multipaths + number;
+
+	print_multipath_conf(conf);
+
+	if (rdev == p->rdev) {
+		if (test_bit(In_sync, &rdev->flags) ||
+		    atomic_read(&rdev->nr_pending)) {
+			pr_warn("hot-remove-disk, slot %d is identified but is still operational!\n", number);
+			err = -EBUSY;
+			goto abort;
+		}
+		p->rdev = NULL;
+		if (!test_bit(RemoveSynchronized, &rdev->flags)) {
+			synchronize_rcu();
+			if (atomic_read(&rdev->nr_pending)) {
+				/* lost the race, try later */
+				err = -EBUSY;
+				p->rdev = rdev;
+				goto abort;
+			}
+		}
+		err = md_integrity_register(mddev);
+	}
+abort:
+
+	print_multipath_conf(conf);
+	return err;
+}
+
+/*
+ * This is a kernel thread which:
+ *
+ *	1.	Retries failed read operations on working multipaths.
+ *	2.	Updates the raid superblock when problems encounter.
+ *	3.	Performs writes following reads for array syncronising.
+ */
+
+static void multipathd(struct md_thread *thread)
+{
+	struct mddev *mddev = thread->mddev;
+	struct multipath_bh *mp_bh;
+	struct bio *bio;
+	unsigned long flags;
+	struct mpconf *conf = mddev->private;
+	struct list_head *head = &conf->retry_list;
+
+	md_check_recovery(mddev);
+	for (;;) {
+		char b[BDEVNAME_SIZE];
+		spin_lock_irqsave(&conf->device_lock, flags);
+		if (list_empty(head))
+			break;
+		mp_bh = list_entry(head->prev, struct multipath_bh, retry_list);
+		list_del(head->prev);
+		spin_unlock_irqrestore(&conf->device_lock, flags);
+
+		bio = &mp_bh->bio;
+		bio->bi_iter.bi_sector = mp_bh->master_bio->bi_iter.bi_sector;
+
+		if ((mp_bh->path = multipath_map (conf))<0) {
+			pr_err("multipath: %s: unrecoverable IO read error for block %llu\n",
+			       bio_devname(bio, b),
+			       (unsigned long long)bio->bi_iter.bi_sector);
+			multipath_end_bh_io(mp_bh, BLK_STS_IOERR);
+		} else {
+			pr_err("multipath: %s: redirecting sector %llu to another IO path\n",
+			       bio_devname(bio, b),
+			       (unsigned long long)bio->bi_iter.bi_sector);
+			*bio = *(mp_bh->master_bio);
+			bio->bi_iter.bi_sector +=
+				conf->multipaths[mp_bh->path].rdev->data_offset;
+			bio_set_dev(bio, conf->multipaths[mp_bh->path].rdev->bdev);
+			bio->bi_opf |= REQ_FAILFAST_TRANSPORT;
+			bio->bi_end_io = multipath_end_request;
+			bio->bi_private = mp_bh;
+			generic_make_request(bio);
+		}
+	}
+	spin_unlock_irqrestore(&conf->device_lock, flags);
+}
+
+static sector_t multipath_size(struct mddev *mddev, sector_t sectors, int raid_disks)
+{
+	WARN_ONCE(sectors || raid_disks,
+		  "%s does not support generic reshape\n", __func__);
+
+	return mddev->dev_sectors;
+}
+
+static int multipath_run (struct mddev *mddev)
+{
+	struct mpconf *conf;
+	int disk_idx;
+	struct multipath_info *disk;
+	struct md_rdev *rdev;
+	int working_disks;
+
+	if (md_check_no_bitmap(mddev))
+		return -EINVAL;
+
+	if (mddev->level != LEVEL_MULTIPATH) {
+		pr_warn("multipath: %s: raid level not set to multipath IO (%d)\n",
+			mdname(mddev), mddev->level);
+		goto out;
+	}
+	/*
+	 * copy the already verified devices into our private MULTIPATH
+	 * bookkeeping area. [whatever we allocate in multipath_run(),
+	 * should be freed in multipath_free()]
+	 */
+
+	conf = kzalloc(sizeof(struct mpconf), GFP_KERNEL);
+	mddev->private = conf;
+	if (!conf)
+		goto out;
+
+	conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks,
+				   GFP_KERNEL);
+	if (!conf->multipaths)
+		goto out_free_conf;
+
+	working_disks = 0;
+	rdev_for_each(rdev, mddev) {
+		disk_idx = rdev->raid_disk;
+		if (disk_idx < 0 ||
+		    disk_idx >= mddev->raid_disks)
+			continue;
+
+		disk = conf->multipaths + disk_idx;
+		disk->rdev = rdev;
+		disk_stack_limits(mddev->gendisk, rdev->bdev,
+				  rdev->data_offset << 9);
+
+		if (!test_bit(Faulty, &rdev->flags))
+			working_disks++;
+	}
+
+	conf->raid_disks = mddev->raid_disks;
+	conf->mddev = mddev;
+	spin_lock_init(&conf->device_lock);
+	INIT_LIST_HEAD(&conf->retry_list);
+
+	if (!working_disks) {
+		pr_warn("multipath: no operational IO paths for %s\n",
+			mdname(mddev));
+		goto out_free_conf;
+	}
+	mddev->degraded = conf->raid_disks - working_disks;
+
+	conf->pool = mempool_create_kmalloc_pool(NR_RESERVED_BUFS,
+						 sizeof(struct multipath_bh));
+	if (conf->pool == NULL)
+		goto out_free_conf;
+
+	mddev->thread = md_register_thread(multipathd, mddev,
+					   "multipath");
+	if (!mddev->thread)
+		goto out_free_conf;
+
+	pr_info("multipath: array %s active with %d out of %d IO paths\n",
+		mdname(mddev), conf->raid_disks - mddev->degraded,
+		mddev->raid_disks);
+	/*
+	 * Ok, everything is just fine now
+	 */
+	md_set_array_sectors(mddev, multipath_size(mddev, 0, 0));
+
+	if (md_integrity_register(mddev))
+		goto out_free_conf;
+
+	return 0;
+
+out_free_conf:
+	mempool_destroy(conf->pool);
+	kfree(conf->multipaths);
+	kfree(conf);
+	mddev->private = NULL;
+out:
+	return -EIO;
+}
+
+static void multipath_free(struct mddev *mddev, void *priv)
+{
+	struct mpconf *conf = priv;
+
+	mempool_destroy(conf->pool);
+	kfree(conf->multipaths);
+	kfree(conf);
+}
+
+static struct md_personality multipath_personality =
+{
+	.name		= "multipath",
+	.level		= LEVEL_MULTIPATH,
+	.owner		= THIS_MODULE,
+	.make_request	= multipath_make_request,
+	.run		= multipath_run,
+	.free		= multipath_free,
+	.status		= multipath_status,
+	.error_handler	= multipath_error,
+	.hot_add_disk	= multipath_add_disk,
+	.hot_remove_disk= multipath_remove_disk,
+	.size		= multipath_size,
+	.congested	= multipath_congested,
+};
+
+static int __init multipath_init (void)
+{
+	return register_md_personality (&multipath_personality);
+}
+
+static void __exit multipath_exit (void)
+{
+	unregister_md_personality (&multipath_personality);
+}
+
+module_init(multipath_init);
+module_exit(multipath_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("simple multi-path personality for MD");
+MODULE_ALIAS("md-personality-7"); /* MULTIPATH */
+MODULE_ALIAS("md-multipath");
+MODULE_ALIAS("md-level--4");
--- /dev/null
+++ b/drivers/md/md-multipath.h
@@ -0,0 +1,31 @@
+#ifndef _MULTIPATH_H
+#define _MULTIPATH_H
+
+struct multipath_info {
+	struct md_rdev	*rdev;
+};
+
+struct mpconf {
+	struct mddev			*mddev;
+	struct multipath_info	*multipaths;
+	int			raid_disks;
+	spinlock_t		device_lock;
+	struct list_head	retry_list;
+
+	mempool_t		*pool;
+};
+
+/*
+ * this is our 'private' 'collective' MULTIPATH buffer head.
+ * it contains information about what kind of IO operations were started
+ * for this MULTIPATH operation, and about their status:
+ */
+
+struct multipath_bh {
+	struct mddev			*mddev;
+	struct bio		*master_bio;
+	struct bio		bio;
+	int			path;
+	struct list_head	retry_list;
+};
+#endif
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -69,7 +69,7 @@
 
 #include <trace/events/block.h>
 #include "md.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 #include "md-cluster.h"
 
 #ifndef MODULE
--- a/drivers/md/multipath.c
+++ /dev/null
@@ -1,509 +0,0 @@
-/*
- * multipath.c : Multiple Devices driver for Linux
- *
- * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
- *
- * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
- *
- * MULTIPATH management functions.
- *
- * derived from raid1.c.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * You should have received a copy of the GNU General Public License
- * (for example /usr/src/linux/COPYING); if not, write to the Free
- * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#include <linux/blkdev.h>
-#include <linux/module.h>
-#include <linux/raid/md_u.h>
-#include <linux/seq_file.h>
-#include <linux/slab.h>
-#include "md.h"
-#include "multipath.h"
-
-#define MAX_WORK_PER_DISK 128
-
-#define	NR_RESERVED_BUFS	32
-
-static int multipath_map (struct mpconf *conf)
-{
-	int i, disks = conf->raid_disks;
-
-	/*
-	 * Later we do read balancing on the read side
-	 * now we use the first available disk.
-	 */
-
-	rcu_read_lock();
-	for (i = 0; i < disks; i++) {
-		struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
-		if (rdev && test_bit(In_sync, &rdev->flags) &&
-		    !test_bit(Faulty, &rdev->flags)) {
-			atomic_inc(&rdev->nr_pending);
-			rcu_read_unlock();
-			return i;
-		}
-	}
-	rcu_read_unlock();
-
-	pr_crit_ratelimited("multipath_map(): no more operational IO paths?\n");
-	return (-1);
-}
-
-static void multipath_reschedule_retry (struct multipath_bh *mp_bh)
-{
-	unsigned long flags;
-	struct mddev *mddev = mp_bh->mddev;
-	struct mpconf *conf = mddev->private;
-
-	spin_lock_irqsave(&conf->device_lock, flags);
-	list_add(&mp_bh->retry_list, &conf->retry_list);
-	spin_unlock_irqrestore(&conf->device_lock, flags);
-	md_wakeup_thread(mddev->thread);
-}
-
-/*
- * multipath_end_bh_io() is called when we have finished servicing a multipathed
- * operation and are ready to return a success/failure code to the buffer
- * cache layer.
- */
-static void multipath_end_bh_io(struct multipath_bh *mp_bh, blk_status_t status)
-{
-	struct bio *bio = mp_bh->master_bio;
-	struct mpconf *conf = mp_bh->mddev->private;
-
-	bio->bi_status = status;
-	bio_endio(bio);
-	mempool_free(mp_bh, conf->pool);
-}
-
-static void multipath_end_request(struct bio *bio)
-{
-	struct multipath_bh *mp_bh = bio->bi_private;
-	struct mpconf *conf = mp_bh->mddev->private;
-	struct md_rdev *rdev = conf->multipaths[mp_bh->path].rdev;
-
-	if (!bio->bi_status)
-		multipath_end_bh_io(mp_bh, 0);
-	else if (!(bio->bi_opf & REQ_RAHEAD)) {
-		/*
-		 * oops, IO error:
-		 */
-		char b[BDEVNAME_SIZE];
-		md_error (mp_bh->mddev, rdev);
-		pr_info("multipath: %s: rescheduling sector %llu\n",
-			bdevname(rdev->bdev,b),
-			(unsigned long long)bio->bi_iter.bi_sector);
-		multipath_reschedule_retry(mp_bh);
-	} else
-		multipath_end_bh_io(mp_bh, bio->bi_status);
-	rdev_dec_pending(rdev, conf->mddev);
-}
-
-static bool multipath_make_request(struct mddev *mddev, struct bio * bio)
-{
-	struct mpconf *conf = mddev->private;
-	struct multipath_bh * mp_bh;
-	struct multipath_info *multipath;
-
-	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
-		md_flush_request(mddev, bio);
-		return true;
-	}
-
-	mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
-
-	mp_bh->master_bio = bio;
-	mp_bh->mddev = mddev;
-
-	mp_bh->path = multipath_map(conf);
-	if (mp_bh->path < 0) {
-		bio_io_error(bio);
-		mempool_free(mp_bh, conf->pool);
-		return true;
-	}
-	multipath = conf->multipaths + mp_bh->path;
-
-	bio_init(&mp_bh->bio, NULL, 0);
-	__bio_clone_fast(&mp_bh->bio, bio);
-
-	mp_bh->bio.bi_iter.bi_sector += multipath->rdev->data_offset;
-	bio_set_dev(&mp_bh->bio, multipath->rdev->bdev);
-	mp_bh->bio.bi_opf |= REQ_FAILFAST_TRANSPORT;
-	mp_bh->bio.bi_end_io = multipath_end_request;
-	mp_bh->bio.bi_private = mp_bh;
-	mddev_check_writesame(mddev, &mp_bh->bio);
-	mddev_check_write_zeroes(mddev, &mp_bh->bio);
-	generic_make_request(&mp_bh->bio);
-	return true;
-}
-
-static void multipath_status(struct seq_file *seq, struct mddev *mddev)
-{
-	struct mpconf *conf = mddev->private;
-	int i;
-
-	seq_printf (seq, " [%d/%d] [", conf->raid_disks,
-		    conf->raid_disks - mddev->degraded);
-	rcu_read_lock();
-	for (i = 0; i < conf->raid_disks; i++) {
-		struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
-		seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
-	}
-	rcu_read_unlock();
-	seq_printf (seq, "]");
-}
-
-static int multipath_congested(struct mddev *mddev, int bits)
-{
-	struct mpconf *conf = mddev->private;
-	int i, ret = 0;
-
-	rcu_read_lock();
-	for (i = 0; i < mddev->raid_disks ; i++) {
-		struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
-		if (rdev && !test_bit(Faulty, &rdev->flags)) {
-			struct request_queue *q = bdev_get_queue(rdev->bdev);
-
-			ret |= bdi_congested(q->backing_dev_info, bits);
-			/* Just like multipath_map, we just check the
-			 * first available device
-			 */
-			break;
-		}
-	}
-	rcu_read_unlock();
-	return ret;
-}
-
-/*
- * Careful, this can execute in IRQ contexts as well!
- */
-static void multipath_error (struct mddev *mddev, struct md_rdev *rdev)
-{
-	struct mpconf *conf = mddev->private;
-	char b[BDEVNAME_SIZE];
-
-	if (conf->raid_disks - mddev->degraded <= 1) {
-		/*
-		 * Uh oh, we can do nothing if this is our last path, but
-		 * first check if this is a queued request for a device
-		 * which has just failed.
-		 */
-		pr_warn("multipath: only one IO path left and IO error.\n");
-		/* leave it active... it's all we have */
-		return;
-	}
-	/*
-	 * Mark disk as unusable
-	 */
-	if (test_and_clear_bit(In_sync, &rdev->flags)) {
-		unsigned long flags;
-		spin_lock_irqsave(&conf->device_lock, flags);
-		mddev->degraded++;
-		spin_unlock_irqrestore(&conf->device_lock, flags);
-	}
-	set_bit(Faulty, &rdev->flags);
-	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
-	pr_err("multipath: IO failure on %s, disabling IO path.\n"
-	       "multipath: Operation continuing on %d IO paths.\n",
-	       bdevname(rdev->bdev, b),
-	       conf->raid_disks - mddev->degraded);
-}
-
-static void print_multipath_conf (struct mpconf *conf)
-{
-	int i;
-	struct multipath_info *tmp;
-
-	pr_debug("MULTIPATH conf printout:\n");
-	if (!conf) {
-		pr_debug("(conf==NULL)\n");
-		return;
-	}
-	pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
-		 conf->raid_disks);
-
-	for (i = 0; i < conf->raid_disks; i++) {
-		char b[BDEVNAME_SIZE];
-		tmp = conf->multipaths + i;
-		if (tmp->rdev)
-			pr_debug(" disk%d, o:%d, dev:%s\n",
-				 i,!test_bit(Faulty, &tmp->rdev->flags),
-				 bdevname(tmp->rdev->bdev,b));
-	}
-}
-
-static int multipath_add_disk(struct mddev *mddev, struct md_rdev *rdev)
-{
-	struct mpconf *conf = mddev->private;
-	struct request_queue *q;
-	int err = -EEXIST;
-	int path;
-	struct multipath_info *p;
-	int first = 0;
-	int last = mddev->raid_disks - 1;
-
-	if (rdev->raid_disk >= 0)
-		first = last = rdev->raid_disk;
-
-	print_multipath_conf(conf);
-
-	for (path = first; path <= last; path++)
-		if ((p=conf->multipaths+path)->rdev == NULL) {
-			q = rdev->bdev->bd_disk->queue;
-			disk_stack_limits(mddev->gendisk, rdev->bdev,
-					  rdev->data_offset << 9);
-
-			err = md_integrity_add_rdev(rdev, mddev);
-			if (err)
-				break;
-			spin_lock_irq(&conf->device_lock);
-			mddev->degraded--;
-			rdev->raid_disk = path;
-			set_bit(In_sync, &rdev->flags);
-			spin_unlock_irq(&conf->device_lock);
-			rcu_assign_pointer(p->rdev, rdev);
-			err = 0;
-			break;
-		}
-
-	print_multipath_conf(conf);
-
-	return err;
-}
-
-static int multipath_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
-{
-	struct mpconf *conf = mddev->private;
-	int err = 0;
-	int number = rdev->raid_disk;
-	struct multipath_info *p = conf->multipaths + number;
-
-	print_multipath_conf(conf);
-
-	if (rdev == p->rdev) {
-		if (test_bit(In_sync, &rdev->flags) ||
-		    atomic_read(&rdev->nr_pending)) {
-			pr_warn("hot-remove-disk, slot %d is identified but is still operational!\n", number);
-			err = -EBUSY;
-			goto abort;
-		}
-		p->rdev = NULL;
-		if (!test_bit(RemoveSynchronized, &rdev->flags)) {
-			synchronize_rcu();
-			if (atomic_read(&rdev->nr_pending)) {
-				/* lost the race, try later */
-				err = -EBUSY;
-				p->rdev = rdev;
-				goto abort;
-			}
-		}
-		err = md_integrity_register(mddev);
-	}
-abort:
-
-	print_multipath_conf(conf);
-	return err;
-}
-
-/*
- * This is a kernel thread which:
- *
- *	1.	Retries failed read operations on working multipaths.
- *	2.	Updates the raid superblock when problems encounter.
- *	3.	Performs writes following reads for array syncronising.
- */
-
-static void multipathd(struct md_thread *thread)
-{
-	struct mddev *mddev = thread->mddev;
-	struct multipath_bh *mp_bh;
-	struct bio *bio;
-	unsigned long flags;
-	struct mpconf *conf = mddev->private;
-	struct list_head *head = &conf->retry_list;
-
-	md_check_recovery(mddev);
-	for (;;) {
-		char b[BDEVNAME_SIZE];
-		spin_lock_irqsave(&conf->device_lock, flags);
-		if (list_empty(head))
-			break;
-		mp_bh = list_entry(head->prev, struct multipath_bh, retry_list);
-		list_del(head->prev);
-		spin_unlock_irqrestore(&conf->device_lock, flags);
-
-		bio = &mp_bh->bio;
-		bio->bi_iter.bi_sector = mp_bh->master_bio->bi_iter.bi_sector;
-
-		if ((mp_bh->path = multipath_map (conf))<0) {
-			pr_err("multipath: %s: unrecoverable IO read error for block %llu\n",
-			       bio_devname(bio, b),
-			       (unsigned long long)bio->bi_iter.bi_sector);
-			multipath_end_bh_io(mp_bh, BLK_STS_IOERR);
-		} else {
-			pr_err("multipath: %s: redirecting sector %llu to another IO path\n",
-			       bio_devname(bio, b),
-			       (unsigned long long)bio->bi_iter.bi_sector);
-			*bio = *(mp_bh->master_bio);
-			bio->bi_iter.bi_sector +=
-				conf->multipaths[mp_bh->path].rdev->data_offset;
-			bio_set_dev(bio, conf->multipaths[mp_bh->path].rdev->bdev);
-			bio->bi_opf |= REQ_FAILFAST_TRANSPORT;
-			bio->bi_end_io = multipath_end_request;
-			bio->bi_private = mp_bh;
-			generic_make_request(bio);
-		}
-	}
-	spin_unlock_irqrestore(&conf->device_lock, flags);
-}
-
-static sector_t multipath_size(struct mddev *mddev, sector_t sectors, int raid_disks)
-{
-	WARN_ONCE(sectors || raid_disks,
-		  "%s does not support generic reshape\n", __func__);
-
-	return mddev->dev_sectors;
-}
-
-static int multipath_run (struct mddev *mddev)
-{
-	struct mpconf *conf;
-	int disk_idx;
-	struct multipath_info *disk;
-	struct md_rdev *rdev;
-	int working_disks;
-
-	if (md_check_no_bitmap(mddev))
-		return -EINVAL;
-
-	if (mddev->level != LEVEL_MULTIPATH) {
-		pr_warn("multipath: %s: raid level not set to multipath IO (%d)\n",
-			mdname(mddev), mddev->level);
-		goto out;
-	}
-	/*
-	 * copy the already verified devices into our private MULTIPATH
-	 * bookkeeping area. [whatever we allocate in multipath_run(),
-	 * should be freed in multipath_free()]
-	 */
-
-	conf = kzalloc(sizeof(struct mpconf), GFP_KERNEL);
-	mddev->private = conf;
-	if (!conf)
-		goto out;
-
-	conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks,
-				   GFP_KERNEL);
-	if (!conf->multipaths)
-		goto out_free_conf;
-
-	working_disks = 0;
-	rdev_for_each(rdev, mddev) {
-		disk_idx = rdev->raid_disk;
-		if (disk_idx < 0 ||
-		    disk_idx >= mddev->raid_disks)
-			continue;
-
-		disk = conf->multipaths + disk_idx;
-		disk->rdev = rdev;
-		disk_stack_limits(mddev->gendisk, rdev->bdev,
-				  rdev->data_offset << 9);
-
-		if (!test_bit(Faulty, &rdev->flags))
-			working_disks++;
-	}
-
-	conf->raid_disks = mddev->raid_disks;
-	conf->mddev = mddev;
-	spin_lock_init(&conf->device_lock);
-	INIT_LIST_HEAD(&conf->retry_list);
-
-	if (!working_disks) {
-		pr_warn("multipath: no operational IO paths for %s\n",
-			mdname(mddev));
-		goto out_free_conf;
-	}
-	mddev->degraded = conf->raid_disks - working_disks;
-
-	conf->pool = mempool_create_kmalloc_pool(NR_RESERVED_BUFS,
-						 sizeof(struct multipath_bh));
-	if (conf->pool == NULL)
-		goto out_free_conf;
-
-	mddev->thread = md_register_thread(multipathd, mddev,
-					   "multipath");
-	if (!mddev->thread)
-		goto out_free_conf;
-
-	pr_info("multipath: array %s active with %d out of %d IO paths\n",
-		mdname(mddev), conf->raid_disks - mddev->degraded,
-		mddev->raid_disks);
-	/*
-	 * Ok, everything is just fine now
-	 */
-	md_set_array_sectors(mddev, multipath_size(mddev, 0, 0));
-
-	if (md_integrity_register(mddev))
-		goto out_free_conf;
-
-	return 0;
-
-out_free_conf:
-	mempool_destroy(conf->pool);
-	kfree(conf->multipaths);
-	kfree(conf);
-	mddev->private = NULL;
-out:
-	return -EIO;
-}
-
-static void multipath_free(struct mddev *mddev, void *priv)
-{
-	struct mpconf *conf = priv;
-
-	mempool_destroy(conf->pool);
-	kfree(conf->multipaths);
-	kfree(conf);
-}
-
-static struct md_personality multipath_personality =
-{
-	.name		= "multipath",
-	.level		= LEVEL_MULTIPATH,
-	.owner		= THIS_MODULE,
-	.make_request	= multipath_make_request,
-	.run		= multipath_run,
-	.free		= multipath_free,
-	.status		= multipath_status,
-	.error_handler	= multipath_error,
-	.hot_add_disk	= multipath_add_disk,
-	.hot_remove_disk= multipath_remove_disk,
-	.size		= multipath_size,
-	.congested	= multipath_congested,
-};
-
-static int __init multipath_init (void)
-{
-	return register_md_personality (&multipath_personality);
-}
-
-static void __exit multipath_exit (void)
-{
-	unregister_md_personality (&multipath_personality);
-}
-
-module_init(multipath_init);
-module_exit(multipath_exit);
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("simple multi-path personality for MD");
-MODULE_ALIAS("md-personality-7"); /* MULTIPATH */
-MODULE_ALIAS("md-multipath");
-MODULE_ALIAS("md-level--4");
--- a/drivers/md/multipath.h
+++ /dev/null
@@ -1,31 +0,0 @@
-#ifndef _MULTIPATH_H
-#define _MULTIPATH_H
-
-struct multipath_info {
-	struct md_rdev	*rdev;
-};
-
-struct mpconf {
-	struct mddev			*mddev;
-	struct multipath_info	*multipaths;
-	int			raid_disks;
-	spinlock_t		device_lock;
-	struct list_head	retry_list;
-
-	mempool_t		*pool;
-};
-
-/*
- * this is our 'private' 'collective' MULTIPATH buffer head.
- * it contains information about what kind of IO operations were started
- * for this MULTIPATH operation, and about their status:
- */
-
-struct multipath_bh {
-	struct mddev			*mddev;
-	struct bio		*master_bio;
-	struct bio		bio;
-	int			path;
-	struct list_head	retry_list;
-};
-#endif
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -43,7 +43,7 @@
 
 #include "md.h"
 #include "raid1.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 
 #define UNSUPPORTED_MDDEV_FLAGS		\
 	((1L << MD_HAS_JOURNAL) |	\
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -29,7 +29,7 @@
 #include "md.h"
 #include "raid10.h"
 #include "raid0.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 
 /*
  * RAID10 provides a combination of RAID0 and RAID1 functionality.
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -23,7 +23,7 @@
 #include <linux/types.h>
 #include "md.h"
 #include "raid5.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 #include "raid5-log.h"
 
 /*
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -63,7 +63,7 @@
 #include "md.h"
 #include "raid5.h"
 #include "raid0.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 #include "raid5-log.h"
 
 #define UNSUPPORTED_MDDEV_FLAGS	(1L << MD_FAILFAST_SUPPORTED)