Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm: tidy local_init
  dm: remove unused flush_all
  dm raid1: separate region_hash interface part1
  dm: mark split bio as cloned
  dm crypt: remove waitqueue
  dm crypt: fix async split
  dm crypt: tidy sector
  dm: remove dm header from targets
  dm: publish array_too_big
  dm exception store: fix misordered writes
  dm exception store: refactor zero_area
  dm snapshot: drop unused last_percent
  dm snapshot: fix primary_pe race
  dm kcopyd: avoid queue shuffle

drivers/md/Makefile

@@ -34,7 +34,7 @@ obj-$(CONFIG_DM_CRYPT)		+= dm-crypt.o
 obj-$(CONFIG_DM_DELAY)		+= dm-delay.o
 obj-$(CONFIG_DM_MULTIPATH)	+= dm-multipath.o dm-round-robin.o
 obj-$(CONFIG_DM_SNAPSHOT)	+= dm-snapshot.o
-obj-$(CONFIG_DM_MIRROR)		+= dm-mirror.o dm-log.o
+obj-$(CONFIG_DM_MIRROR)		+= dm-mirror.o dm-log.o dm-region-hash.o
 obj-$(CONFIG_DM_ZERO)		+= dm-zero.o
 
 quiet_cmd_unroll = UNROLL  $@

drivers/md/dm-crypt.c

@@ -23,7 +23,7 @@
 #include <asm/page.h>
 #include <asm/unaligned.h>
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "crypt"
 #define MESG_STR(x) x, sizeof(x)
@@ -56,6 +56,7 @@ struct dm_crypt_io {
 	atomic_t pending;
 	int error;
 	sector_t sector;
+	struct dm_crypt_io *base_io;
 };
 
 struct dm_crypt_request {
@@ -93,7 +94,6 @@ struct crypt_config {
 
 	struct workqueue_struct *io_queue;
 	struct workqueue_struct *crypt_queue;
-	wait_queue_head_t writeq;
 
 	/*
 	 * crypto related data
@@ -534,6 +534,7 @@ static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti,
 	io->base_bio = bio;
 	io->sector = sector;
 	io->error = 0;
+	io->base_io = NULL;
 	atomic_set(&io->pending, 0);
 
 	return io;
@@ -547,6 +548,7 @@ static void crypt_inc_pending(struct dm_crypt_io *io)
 /*
  * One of the bios was finished. Check for completion of
  * the whole request and correctly clean up the buffer.
+ * If base_io is set, wait for the last fragment to complete.
  */
 static void crypt_dec_pending(struct dm_crypt_io *io)
 {
@@ -555,7 +557,14 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
 	if (!atomic_dec_and_test(&io->pending))
 		return;
 
-	bio_endio(io->base_bio, io->error);
+	if (likely(!io->base_io))
+		bio_endio(io->base_bio, io->error);
+	else {
+		if (io->error && !io->base_io->error)
+			io->base_io->error = io->error;
+		crypt_dec_pending(io->base_io);
+	}
+
 	mempool_free(io, cc->io_pool);
 }
 
@@ -646,10 +655,7 @@ static void kcryptd_io_read(struct dm_crypt_io *io)
 static void kcryptd_io_write(struct dm_crypt_io *io)
 {
 	struct bio *clone = io->ctx.bio_out;
-	struct crypt_config *cc = io->target->private;
-
 	generic_make_request(clone);
-	wake_up(&cc->writeq);
 }
 
 static void kcryptd_io(struct work_struct *work)
@@ -688,7 +694,6 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
 	BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
 
 	clone->bi_sector = cc->start + io->sector;
-	io->sector += bio_sectors(clone);
 
 	if (async)
 		kcryptd_queue_io(io);
@@ -700,16 +705,18 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 {
 	struct crypt_config *cc = io->target->private;
 	struct bio *clone;
+	struct dm_crypt_io *new_io;
 	int crypt_finished;
 	unsigned out_of_pages = 0;
 	unsigned remaining = io->base_bio->bi_size;
+	sector_t sector = io->sector;
 	int r;
 
 	/*
 	 * Prevent io from disappearing until this function completes.
 	 */
 	crypt_inc_pending(io);
-	crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
+	crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
 
 	/*
 	 * The allocated buffers can be smaller than the whole bio,
@@ -726,6 +733,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 		io->ctx.idx_out = 0;
 
 		remaining -= clone->bi_size;
+		sector += bio_sectors(clone);
 
 		crypt_inc_pending(io);
 		r = crypt_convert(cc, &io->ctx);
@@ -741,6 +749,8 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 			 */
 			if (unlikely(r < 0))
 				break;
+
+			io->sector = sector;
 		}
 
 		/*
@@ -750,8 +760,33 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 		if (unlikely(out_of_pages))
 			congestion_wait(WRITE, HZ/100);
 
-		if (unlikely(remaining))
-			wait_event(cc->writeq, !atomic_read(&io->ctx.pending));
+		/*
+		 * With async crypto it is unsafe to share the crypto context
+		 * between fragments, so switch to a new dm_crypt_io structure.
+		 */
+		if (unlikely(!crypt_finished && remaining)) {
+			new_io = crypt_io_alloc(io->target, io->base_bio,
+						sector);
+			crypt_inc_pending(new_io);
+			crypt_convert_init(cc, &new_io->ctx, NULL,
+					   io->base_bio, sector);
+			new_io->ctx.idx_in = io->ctx.idx_in;
+			new_io->ctx.offset_in = io->ctx.offset_in;
+
+			/*
+			 * Fragments after the first use the base_io
+			 * pending count.
+			 */
+			if (!io->base_io)
+				new_io->base_io = io;
+			else {
+				new_io->base_io = io->base_io;
+				crypt_inc_pending(io->base_io);
+				crypt_dec_pending(io);
+			}
+
+			io = new_io;
+		}
 	}
 
 	crypt_dec_pending(io);
@@ -1078,7 +1113,6 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad_crypt_queue;
 	}
 
-	init_waitqueue_head(&cc->writeq);
 	ti->private = cc;
 	return 0;
 

drivers/md/dm-delay.c

@@ -13,7 +13,8 @@
 #include <linux/bio.h>
 #include <linux/slab.h>
 
-#include "dm.h"
+#include <linux/device-mapper.h>
+
 #include "dm-bio-list.h"
 
 #define DM_MSG_PREFIX "delay"

drivers/md/dm-exception-store.c

@@ -7,7 +7,6 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
 #include "dm-snap.h"
 
 #include <linux/mm.h>
@@ -104,6 +103,11 @@ struct pstore {
 	 */
 	void *area;
 
+	/*
+	 * An area of zeros used to clear the next area.
+	 */
+	void *zero_area;
+
 	/*
 	 * Used to keep track of which metadata area the data in
 	 * 'chunk' refers to.
@@ -149,6 +153,13 @@ static int alloc_area(struct pstore *ps)
 	if (!ps->area)
 		return r;
 
+	ps->zero_area = vmalloc(len);
+	if (!ps->zero_area) {
+		vfree(ps->area);
+		return r;
+	}
+	memset(ps->zero_area, 0, len);
+
 	return 0;
 }
 
@@ -156,6 +167,8 @@ static void free_area(struct pstore *ps)
 {
 	vfree(ps->area);
 	ps->area = NULL;
+	vfree(ps->zero_area);
+	ps->zero_area = NULL;
 }
 
 struct mdata_req {
@@ -220,25 +233,41 @@ static chunk_t area_location(struct pstore *ps, chunk_t area)
  * Read or write a metadata area.  Remembering to skip the first
  * chunk which holds the header.
  */
-static int area_io(struct pstore *ps, chunk_t area, int rw)
+static int area_io(struct pstore *ps, int rw)
 {
 	int r;
 	chunk_t chunk;
 
-	chunk = area_location(ps, area);
+	chunk = area_location(ps, ps->current_area);
 
 	r = chunk_io(ps, chunk, rw, 0);
 	if (r)
 		return r;
 
-	ps->current_area = area;
 	return 0;
 }
 
-static int zero_area(struct pstore *ps, chunk_t area)
+static void zero_memory_area(struct pstore *ps)
 {
 	memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
-	return area_io(ps, area, WRITE);
+}
+
+static int zero_disk_area(struct pstore *ps, chunk_t area)
+{
+	struct dm_io_region where = {
+		.bdev = ps->snap->cow->bdev,
+		.sector = ps->snap->chunk_size * area_location(ps, area),
+		.count = ps->snap->chunk_size,
+	};
+	struct dm_io_request io_req = {
+		.bi_rw = WRITE,
+		.mem.type = DM_IO_VMA,
+		.mem.ptr.vma = ps->zero_area,
+		.client = ps->io_client,
+		.notify.fn = NULL,
+	};
+
+	return dm_io(&io_req, 1, &where, NULL);
 }
 
 static int read_header(struct pstore *ps, int *new_snapshot)
@@ -411,15 +440,14 @@ static int insert_exceptions(struct pstore *ps, int *full)
 
 static int read_exceptions(struct pstore *ps)
 {
-	chunk_t area;
 	int r, full = 1;
 
 	/*
 	 * Keeping reading chunks and inserting exceptions until
 	 * we find a partially full area.
 	 */
-	for (area = 0; full; area++) {
-		r = area_io(ps, area, READ);
+	for (ps->current_area = 0; full; ps->current_area++) {
+		r = area_io(ps, READ);
 		if (r)
 			return r;
 
@@ -428,6 +456,8 @@ static int read_exceptions(struct pstore *ps)
 			return r;
 	}
 
+	ps->current_area--;
+
 	return 0;
 }
 
@@ -486,12 +516,13 @@ static int persistent_read_metadata(struct exception_store *store)
 			return r;
 		}
 
-		r = zero_area(ps, 0);
+		ps->current_area = 0;
+		zero_memory_area(ps);
+		r = zero_disk_area(ps, 0);
 		if (r) {
-			DMWARN("zero_area(0) failed");
+			DMWARN("zero_disk_area(0) failed");
 			return r;
 		}
-
 	} else {
 		/*
 		 * Sanity checks.
@@ -551,7 +582,6 @@ static void persistent_commit(struct exception_store *store,
 			      void (*callback) (void *, int success),
 			      void *callback_context)
 {
-	int r;
 	unsigned int i;
 	struct pstore *ps = get_info(store);
 	struct disk_exception de;
@@ -572,33 +602,41 @@ static void persistent_commit(struct exception_store *store,
 	cb->context = callback_context;
 
 	/*
-	 * If there are no more exceptions in flight, or we have
-	 * filled this metadata area we commit the exceptions to
-	 * disk.
+	 * If there are exceptions in flight and we have not yet
+	 * filled this metadata area there's nothing more to do.
 	 */
-	if (atomic_dec_and_test(&ps->pending_count) ||
-	    (ps->current_committed == ps->exceptions_per_area)) {
-		r = area_io(ps, ps->current_area, WRITE);
-		if (r)
-			ps->valid = 0;
+	if (!atomic_dec_and_test(&ps->pending_count) &&
+	    (ps->current_committed != ps->exceptions_per_area))
+		return;
 
-		/*
-		 * Have we completely filled the current area ?
-		 */
-		if (ps->current_committed == ps->exceptions_per_area) {
-			ps->current_committed = 0;
-			r = zero_area(ps, ps->current_area + 1);
-			if (r)
-				ps->valid = 0;
-		}
+	/*
+	 * If we completely filled the current area, then wipe the next one.
+	 */
+	if ((ps->current_committed == ps->exceptions_per_area) &&
+	     zero_disk_area(ps, ps->current_area + 1))
+		ps->valid = 0;
 
-		for (i = 0; i < ps->callback_count; i++) {
-			cb = ps->callbacks + i;
-			cb->callback(cb->context, r == 0 ? 1 : 0);
-		}
+	/*
+	 * Commit exceptions to disk.
+	 */
+	if (ps->valid && area_io(ps, WRITE))
+		ps->valid = 0;
 
-		ps->callback_count = 0;
+	/*
+	 * Advance to the next area if this one is full.
+	 */
+	if (ps->current_committed == ps->exceptions_per_area) {
+		ps->current_committed = 0;
+		ps->current_area++;
+		zero_memory_area(ps);
 	}
+
+	for (i = 0; i < ps->callback_count; i++) {
+		cb = ps->callbacks + i;
+		cb->callback(cb->context, ps->valid);
+	}
+
+	ps->callback_count = 0;
 }
 
 static void persistent_drop(struct exception_store *store)

drivers/md/dm-io.c

@@ -5,7 +5,7 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #include <linux/bio.h>
 #include <linux/mempool.h>

drivers/md/dm-kcopyd.c

@@ -22,6 +22,7 @@
 #include <linux/vmalloc.h>
 #include <linux/workqueue.h>
 #include <linux/mutex.h>
+#include <linux/device-mapper.h>
 #include <linux/dm-kcopyd.h>
 
 #include "dm.h"
@@ -268,6 +269,17 @@ static void push(struct list_head *jobs, struct kcopyd_job *job)
 	spin_unlock_irqrestore(&kc->job_lock, flags);
 }
 
+
+static void push_head(struct list_head *jobs, struct kcopyd_job *job)
+{
+	unsigned long flags;
+	struct dm_kcopyd_client *kc = job->kc;
+
+	spin_lock_irqsave(&kc->job_lock, flags);
+	list_add(&job->list, jobs);
+	spin_unlock_irqrestore(&kc->job_lock, flags);
+}
+
 /*
  * These three functions process 1 item from the corresponding
  * job list.
@@ -398,7 +410,7 @@ static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc,
 			 * We couldn't service this job ATM, so
 			 * push this job back onto the list.
 			 */
-			push(jobs, job);
+			push_head(jobs, job);
 			break;
 		}
 

drivers/md/dm-linear.c

@@ -5,12 +5,12 @@
  */
 
 #include "dm.h"
-
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/blkdev.h>
 #include <linux/bio.h>
 #include <linux/slab.h>
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "linear"
 

drivers/md/dm-log.c

@@ -12,7 +12,7 @@
 #include <linux/dm-io.h>
 #include <linux/dm-dirty-log.h>
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "dirty region log"
 

drivers/md/dm-mpath.c

@@ -5,7 +5,8 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
+
 #include "dm-path-selector.h"
 #include "dm-bio-list.h"
 #include "dm-bio-record.h"

drivers/md/dm-path-selector.c

@@ -9,7 +9,8 @@
  * Path selector registration.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
+
 #include "dm-path-selector.h"
 
 #include <linux/slab.h>

drivers/md/dm-round-robin.c

@@ -9,7 +9,8 @@
  * Round-robin path selector.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
+
 #include "dm-path-selector.h"
 
 #include <linux/slab.h>

drivers/md/dm-snap.c

@@ -600,7 +600,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	s->valid = 1;
 	s->active = 0;
-	s->last_percent = 0;
 	init_rwsem(&s->lock);
 	spin_lock_init(&s->pe_lock);
 	s->ti = ti;
@@ -824,8 +823,10 @@ static struct bio *put_pending_exception(struct dm_snap_pending_exception *pe)
 	 * the bios for the original write to the origin.
 	 */
 	if (primary_pe &&
-	    atomic_dec_and_test(&primary_pe->ref_count))
+	    atomic_dec_and_test(&primary_pe->ref_count)) {
 		origin_bios = bio_list_get(&primary_pe->origin_bios);
+		free_pending_exception(primary_pe);
+	}
 
 	/*
 	 * Free the pe if it's not linked to an origin write or if
@@ -834,12 +835,6 @@ static struct bio *put_pending_exception(struct dm_snap_pending_exception *pe)
 	if (!primary_pe || primary_pe != pe)
 		free_pending_exception(pe);
 
-	/*
-	 * Free the primary pe if nothing references it.
-	 */
-	if (primary_pe && !atomic_read(&primary_pe->ref_count))
-		free_pending_exception(primary_pe);
-
 	return origin_bios;
 }
 

drivers/md/dm-snap.h

@@ -9,7 +9,7 @@
 #ifndef DM_SNAPSHOT_H
 #define DM_SNAPSHOT_H
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 #include "dm-bio-list.h"
 #include <linux/blkdev.h>
 #include <linux/workqueue.h>
@@ -158,9 +158,6 @@ struct dm_snapshot {
 	/* Used for display of table */
 	char type;
 
-	/* The last percentage we notified */
-	int last_percent;
-
 	mempool_t *pending_pool;
 
 	struct exception_table pending;

drivers/md/dm-stripe.c

@@ -4,7 +4,7 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #include <linux/module.h>
 #include <linux/init.h>
@@ -60,8 +60,8 @@ static inline struct stripe_c *alloc_context(unsigned int stripes)
 {
 	size_t len;
 
-	if (array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
-			  stripes))
+	if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
+			     stripes))
 		return NULL;
 
 	len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes);

drivers/md/dm-zero.c

@@ -4,7 +4,7 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #include <linux/module.h>
 #include <linux/init.h>

drivers/md/dm.c

@@ -76,7 +76,6 @@ union map_info *dm_get_mapinfo(struct bio *bio)
  */
 struct dm_wq_req {
 	enum {
-		DM_WQ_FLUSH_ALL,
 		DM_WQ_FLUSH_DEFERRED,
 	} type;
 	struct work_struct work;
@@ -151,40 +150,40 @@ static struct kmem_cache *_tio_cache;
 
 static int __init local_init(void)
 {
-	int r;
+	int r = -ENOMEM;
 
 	/* allocate a slab for the dm_ios */
 	_io_cache = KMEM_CACHE(dm_io, 0);
 	if (!_io_cache)
-		return -ENOMEM;
+		return r;
 
 	/* allocate a slab for the target ios */
 	_tio_cache = KMEM_CACHE(dm_target_io, 0);
-	if (!_tio_cache) {
-		kmem_cache_destroy(_io_cache);
-		return -ENOMEM;
-	}
+	if (!_tio_cache)
+		goto out_free_io_cache;
 
 	r = dm_uevent_init();
-	if (r) {
-		kmem_cache_destroy(_tio_cache);
-		kmem_cache_destroy(_io_cache);
-		return r;
-	}
+	if (r)
+		goto out_free_tio_cache;
 
 	_major = major;
 	r = register_blkdev(_major, _name);
-	if (r < 0) {
-		kmem_cache_destroy(_tio_cache);
-		kmem_cache_destroy(_io_cache);
-		dm_uevent_exit();
-		return r;
-	}
+	if (r < 0)
+		goto out_uevent_exit;
 
 	if (!_major)
 		_major = r;
 
 	return 0;
+
+out_uevent_exit:
+	dm_uevent_exit();
+out_free_tio_cache:
+	kmem_cache_destroy(_tio_cache);
+out_free_io_cache:
+	kmem_cache_destroy(_io_cache);
+
+	return r;
 }
 
 static void local_exit(void)
@@ -669,6 +668,7 @@ static struct bio *split_bvec(struct bio *bio, sector_t sector,
 	clone->bi_size = to_bytes(len);
 	clone->bi_io_vec->bv_offset = offset;
 	clone->bi_io_vec->bv_len = clone->bi_size;
+	clone->bi_flags |= 1 << BIO_CLONED;
 
 	return clone;
 }
@@ -1394,9 +1394,6 @@ static void dm_wq_work(struct work_struct *work)
 
 	down_write(&md->io_lock);
 	switch (req->type) {
-	case DM_WQ_FLUSH_ALL:
-		__merge_pushback_list(md);
-		/* pass through */
 	case DM_WQ_FLUSH_DEFERRED:
 		__flush_deferred_io(md);
 		break;
@@ -1526,7 +1523,7 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
 		if (!md->suspended_bdev) {
 			DMWARN("bdget failed in dm_suspend");
 			r = -ENOMEM;
-			goto flush_and_out;
+			goto out;
 		}
 
 		/*
@@ -1577,14 +1574,6 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
 
 	set_bit(DMF_SUSPENDED, &md->flags);
 
-flush_and_out:
-	if (r && noflush)
-		/*
-		 * Because there may be already I/Os in the pushback list,
-		 * flush them before return.
-		 */
-		dm_queue_flush(md, DM_WQ_FLUSH_ALL, NULL);
-
 out:
 	if (r && md->suspended_bdev) {
 		bdput(md->suspended_bdev);

drivers/md/dm.h

@@ -62,15 +62,6 @@ void dm_put_target_type(struct target_type *t);
 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 					void *param), void *param);
 
-/*-----------------------------------------------------------------
- * Useful inlines.
- *---------------------------------------------------------------*/
-static inline int array_too_big(unsigned long fixed, unsigned long obj,
-				unsigned long num)
-{
-	return (num > (ULONG_MAX - fixed) / obj);
-}
-
 int dm_split_args(int *argc, char ***argvp, char *input);
 
 /*

include/linux/device-mapper.h

@@ -354,6 +354,9 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
  */
 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
 
+#define dm_array_too_big(fixed, obj, num) \
+	((num) > (UINT_MAX - (fixed)) / (obj))
+
 static inline sector_t to_sector(unsigned long n)
 {
 	return (n >> SECTOR_SHIFT);

include/linux/dm-region-hash.h

+/*
+ * Copyright (C) 2003 Sistina Software Limited.
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
+ *
+ * Device-Mapper dirty region hash interface.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef DM_REGION_HASH_H
+#define DM_REGION_HASH_H
+
+#include <linux/dm-dirty-log.h>
+
+/*-----------------------------------------------------------------
+ * Region hash
+ *----------------------------------------------------------------*/
+struct dm_region_hash;
+struct dm_region;
+
+/*
+ * States a region can have.
+ */
+enum dm_rh_region_states {
+	DM_RH_CLEAN	 = 0x01,	/* No writes in flight. */
+	DM_RH_DIRTY	 = 0x02,	/* Writes in flight. */
+	DM_RH_NOSYNC	 = 0x04,	/* Out of sync. */
+	DM_RH_RECOVERING = 0x08,	/* Under resynchronization. */
+};
+
+/*
+ * Region hash create/destroy.
+ */
+struct bio_list;
+struct dm_region_hash *dm_region_hash_create(
+		void *context, void (*dispatch_bios)(void *context,
+						     struct bio_list *bios),
+		void (*wakeup_workers)(void *context),
+		void (*wakeup_all_recovery_waiters)(void *context),
+		sector_t target_begin, unsigned max_recovery,
+		struct dm_dirty_log *log, uint32_t region_size,
+		region_t nr_regions);
+void dm_region_hash_destroy(struct dm_region_hash *rh);
+
+struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh);
+
+/*
+ * Conversion functions.
+ */
+region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio);
+sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region);
+void *dm_rh_region_context(struct dm_region *reg);
+
+/*
+ * Get region size and key (ie. number of the region).
+ */
+sector_t dm_rh_get_region_size(struct dm_region_hash *rh);
+region_t dm_rh_get_region_key(struct dm_region *reg);
+
+/*
+ * Get/set/update region state (and dirty log).
+ *
+ */
+int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block);
+void dm_rh_set_state(struct dm_region_hash *rh, region_t region,
+		     enum dm_rh_region_states state, int may_block);
+
+/* Non-zero errors_handled leaves the state of the region NOSYNC */
+void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled);
+
+/* Flush the region hash and dirty log. */
+int dm_rh_flush(struct dm_region_hash *rh);
+
+/* Inc/dec pending count on regions. */
+void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios);
+void dm_rh_dec(struct dm_region_hash *rh, region_t region);
+
+/* Delay bios on regions. */
+void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio);
+
+void dm_rh_mark_nosync(struct dm_region_hash *rh,
+		       struct bio *bio, unsigned done, int error);
+
+/*
+ * Region recovery control.
+ */
+
+/* Prepare some regions for recovery by starting to quiesce them. */
+void dm_rh_recovery_prepare(struct dm_region_hash *rh);
+
+/* Try fetching a quiesced region for recovery. */
+struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh);
+
+/* Report recovery end on a region. */
+void dm_rh_recovery_end(struct dm_region *reg, int error);
+
+/* Returns number of regions with recovery work outstanding. */
+int dm_rh_recovery_in_flight(struct dm_region_hash *rh);
+
+/* Start/stop recovery. */
+void dm_rh_start_recovery(struct dm_region_hash *rh);
+void dm_rh_stop_recovery(struct dm_region_hash *rh);
+
+#endif /* DM_REGION_HASH_H */