X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fmd%2Fdm.c;h=4d710b7a133ba69570f0de74c5f7c78ec2aff63f;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=f6b03957efc7b8bbd70f28f8ca1230b95ffeb4a3;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f6b03957e..4d710b7a1 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -10,6 +10,7 @@
 
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/moduleparam.h>
 #include <linux/blkpg.h>
 #include <linux/bio.h>
@@ -17,6 +18,8 @@
 #include <linux/mempool.h>
 #include <linux/slab.h>
 #include <linux/idr.h>
+#include <linux/hdreg.h>
+#include <linux/blktrace_api.h>
 
 static const char *_name = DM_NAME;
 
@@ -31,6 +34,7 @@ struct dm_io {
 	int error;
 	struct bio *bio;
 	atomic_t io_count;
+	unsigned long start_time;
 };
 
 /*
@@ -55,10 +59,11 @@ union map_info *dm_get_mapinfo(struct bio *bio)
  */
 #define DMF_BLOCK_IO 0
 #define DMF_SUSPENDED 1
-#define DMF_FS_LOCKED 2
+#define DMF_FROZEN 2
 
 struct mapped_device {
-	struct rw_semaphore lock;
+	struct rw_semaphore io_lock;
+	struct semaphore suspend_lock;
 	rwlock_t map_lock;
 	atomic_t holders;
 
@@ -66,6 +71,7 @@ struct mapped_device {
 
 	request_queue_t *queue;
 	struct gendisk *disk;
+	char name[16];
 
 	void *interface_ptr;
 
@@ -97,7 +103,10 @@ struct mapped_device {
 	 * freeze/thaw support require holding onto a super block
 	 */
 	struct super_block *frozen_sb;
-	struct block_device *frozen_bdev;
+	struct block_device *suspended_bdev;
+
+	/* forced geometry settings */
+	struct hd_geometry geometry;
 };
 
 #define MIN_IOS 256
@@ -223,6 +232,13 @@ static int dm_blk_close(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+	struct mapped_device *md = bdev->bd_disk->private_data;
+
+	return dm_get_geometry(md, geo);
+}
+
 static inline struct dm_io *alloc_io(struct mapped_device *md)
 {
 	return mempool_alloc(md->io_pool, GFP_NOIO);
@@ -243,21 +259,51 @@ static inline void free_tio(struct mapped_device *md, struct target_io *tio)
 	mempool_free(tio, md->tio_pool);
 }
 
+static void start_io_acct(struct dm_io *io)
+{
+	struct mapped_device *md = io->md;
+
+	io->start_time = jiffies;
+
+	preempt_disable();
+	disk_round_stats(dm_disk(md));
+	preempt_enable();
+	dm_disk(md)->in_flight = atomic_inc_return(&md->pending);
+}
+
+static int end_io_acct(struct dm_io *io)
+{
+	struct mapped_device *md = io->md;
+	struct bio *bio = io->bio;
+	unsigned long duration = jiffies - io->start_time;
+	int pending;
+	int rw = bio_data_dir(bio);
+
+	preempt_disable();
+	disk_round_stats(dm_disk(md));
+	preempt_enable();
+	dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending);
+
+	disk_stat_add(dm_disk(md), ticks[rw], duration);
+
+	return !pending;
+}
+
 /*
  * Add the bio to the list of deferred io.
  */
 static int queue_io(struct mapped_device *md, struct bio *bio)
 {
-	down_write(&md->lock);
+	down_write(&md->io_lock);
 
 	if (!test_bit(DMF_BLOCK_IO, &md->flags)) {
-		up_write(&md->lock);
+		up_write(&md->io_lock);
 		return 1;
 	}
 
 	bio_list_add(&md->deferred, bio);
 
-	up_write(&md->lock);
+	up_write(&md->io_lock);
 	return 0;		/* deferred successfully */
 }
 
@@ -279,6 +325,33 @@ struct dm_table *dm_get_table(struct mapped_device *md)
 	return t;
 }
 
+/*
+ * Get the geometry associated with a dm device
+ */
+int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
+{
+	*geo = md->geometry;
+
+	return 0;
+}
+
+/*
+ * Set the geometry of a device.
+ */
+int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
+{
+	sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
+
+	if (geo->start > sz) {
+		DMWARN("Start sector is beyond the geometry limits.");
+		return -EINVAL;
+	}
+
+	md->geometry = *geo;
+
+	return 0;
+}
+
 /*-----------------------------------------------------------------
  * CRUD START:
  *   A more elegant soln is in the works that uses the queue
@@ -292,16 +365,18 @@ struct dm_table *dm_get_table(struct mapped_device *md)
  * Decrements the number of outstanding ios that a bio has been
  * cloned into, completing the original io if necc.
  */
-static inline void dec_pending(struct dm_io *io, int error)
+static void dec_pending(struct dm_io *io, int error)
 {
 	if (error)
 		io->error = error;
 
 	if (atomic_dec_and_test(&io->io_count)) {
-		if (atomic_dec_and_test(&io->md->pending))
+		if (end_io_acct(io))
 			/* nudge anyone waiting on suspend queue */
 			wake_up(&io->md->wait);
 
+		blk_add_trace_bio(io->md->queue, io->bio, BLK_TA_COMPLETE);
+
 		bio_endio(io->bio, io->bio->bi_size, io->error);
 		free_io(io->md, io);
 	}
@@ -360,6 +435,7 @@ static void __map_bio(struct dm_target *ti, struct bio *clone,
 		      struct target_io *tio)
 {
 	int r;
+	sector_t sector;
 
 	/*
 	 * Sanity checks.
@@ -375,16 +451,23 @@ static void __map_bio(struct dm_target *ti, struct bio *clone,
 	 * this io.
 	 */
 	atomic_inc(&tio->io->io_count);
+	sector = clone->bi_sector;
 	r = ti->type->map(ti, clone, &tio->info);
-	if (r > 0)
+	if (r > 0) {
 		/* the bio has been remapped so dispatch it */
+
+		blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, 
+				    tio->io->bio->bi_bdev->bd_dev, sector, 
+				    clone->bi_sector);
+
 		generic_make_request(clone);
+	}
 
 	else if (r < 0) {
 		/* error the io and bail out */
 		struct dm_io *io = tio->io;
 		free_tio(tio->io->md, tio);
-		dec_pending(io, -EIO);
+		dec_pending(io, r);
 		bio_put(clone);
 	}
 }
@@ -399,6 +482,11 @@ struct clone_info {
 	unsigned short idx;
 };
 
+static void dm_bio_destructor(struct bio *bio)
+{
+	bio_free(bio, dm_set);
+}
+
 /*
  * Creates a little bio that is just does part of a bvec.
  */
@@ -410,6 +498,7 @@ static struct bio *split_bvec(struct bio *bio, sector_t sector,
 	struct bio_vec *bv = bio->bi_io_vec + idx;
 
 	clone = bio_alloc_bioset(GFP_NOIO, 1, dm_set);
+	clone->bi_destructor = dm_bio_destructor;
 	*clone->bi_io_vec = *bv;
 
 	clone->bi_sector = sector;
@@ -495,30 +584,35 @@ static void __clone_and_map(struct clone_info *ci)
 
 	} else {
 		/*
-		 * Create two copy bios to deal with io that has
-		 * been split across a target.
+		 * Handle a bvec that must be split between two or more targets.
 		 */
 		struct bio_vec *bv = bio->bi_io_vec + ci->idx;
+		sector_t remaining = to_sector(bv->bv_len);
+		unsigned int offset = 0;
 
-		clone = split_bvec(bio, ci->sector, ci->idx,
-				   bv->bv_offset, max);
-		__map_bio(ti, clone, tio);
+		do {
+			if (offset) {
+				ti = dm_table_find_target(ci->map, ci->sector);
+				max = max_io_len(ci->md, ci->sector, ti);
 
-		ci->sector += max;
-		ci->sector_count -= max;
-		ti = dm_table_find_target(ci->map, ci->sector);
-
-		len = to_sector(bv->bv_len) - max;
-		clone = split_bvec(bio, ci->sector, ci->idx,
-				   bv->bv_offset + to_bytes(max), len);
-		tio = alloc_tio(ci->md);
-		tio->io = ci->io;
-		tio->ti = ti;
-		memset(&tio->info, 0, sizeof(tio->info));
-		__map_bio(ti, clone, tio);
+				tio = alloc_tio(ci->md);
+				tio->io = ci->io;
+				tio->ti = ti;
+				memset(&tio->info, 0, sizeof(tio->info));
+			}
+
+			len = min(remaining, max);
+
+			clone = split_bvec(bio, ci->sector, ci->idx,
+					   bv->bv_offset + offset, len);
+
+			__map_bio(ti, clone, tio);
+
+			ci->sector += len;
+			ci->sector_count -= len;
+			offset += to_bytes(len);
+		} while (remaining -= len);
 
-		ci->sector += len;
-		ci->sector_count -= len;
 		ci->idx++;
 	}
 }
@@ -547,7 +641,7 @@ static void __split_bio(struct mapped_device *md, struct bio *bio)
 	ci.sector_count = bio_sectors(bio);
 	ci.idx = bio->bi_idx;
 
-	atomic_inc(&md->pending);
+	start_io_acct(ci.io);
 	while (ci.sector_count)
 		__clone_and_map(&ci);
 
@@ -566,16 +660,20 @@ static void __split_bio(struct mapped_device *md, struct bio *bio)
 static int dm_request(request_queue_t *q, struct bio *bio)
 {
 	int r;
+	int rw = bio_data_dir(bio);
 	struct mapped_device *md = q->queuedata;
 
-	down_read(&md->lock);
+	down_read(&md->io_lock);
+
+	disk_stat_inc(dm_disk(md), ios[rw]);
+	disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio));
 
 	/*
 	 * If we're suspended we have to queue
 	 * this io for later.
 	 */
 	while (test_bit(DMF_BLOCK_IO, &md->flags)) {
-		up_read(&md->lock);
+		up_read(&md->io_lock);
 
 		if (bio_rw(bio) == READA) {
 			bio_io_error(bio, bio->bi_size);
@@ -594,11 +692,11 @@ static int dm_request(request_queue_t *q, struct bio *bio)
 		 * We're in a while loop, because someone could suspend
 		 * before we get to the following read lock.
 		 */
-		down_read(&md->lock);
+		down_read(&md->io_lock);
 	}
 
 	__split_bio(md, bio);
-	up_read(&md->lock);
+	up_read(&md->io_lock);
 	return 0;
 }
 
@@ -610,7 +708,7 @@ static int dm_flush_all(request_queue_t *q, struct gendisk *disk,
 	int ret = -ENXIO;
 
 	if (map) {
-		ret = dm_table_flush_all(md->map);
+		ret = dm_table_flush_all(map);
 		dm_table_put(map);
 	}
 
@@ -646,14 +744,14 @@ static int dm_any_congested(void *congested_data, int bdi_bits)
 /*-----------------------------------------------------------------
  * An IDR is used to keep track of allocated minor numbers.
  *---------------------------------------------------------------*/
-static DECLARE_MUTEX(_minor_lock);
+static DEFINE_MUTEX(_minor_lock);
 static DEFINE_IDR(_minor_idr);
 
 static void free_minor(unsigned int minor)
 {
-	down(&_minor_lock);
+	mutex_lock(&_minor_lock);
 	idr_remove(&_minor_idr, minor);
-	up(&_minor_lock);
+	mutex_unlock(&_minor_lock);
 }
 
 /*
@@ -666,7 +764,7 @@ static int specific_minor(struct mapped_device *md, unsigned int minor)
 	if (minor >= (1 << MINORBITS))
 		return -EINVAL;
 
-	down(&_minor_lock);
+	mutex_lock(&_minor_lock);
 
 	if (idr_find(&_minor_idr, minor)) {
 		r = -EBUSY;
@@ -691,7 +789,7 @@ static int specific_minor(struct mapped_device *md, unsigned int minor)
 	}
 
 out:
-	up(&_minor_lock);
+	mutex_unlock(&_minor_lock);
 	return r;
 }
 
@@ -700,7 +798,7 @@ static int next_free_minor(struct mapped_device *md, unsigned int *minor)
 	int r;
 	unsigned int m;
 
-	down(&_minor_lock);
+	mutex_lock(&_minor_lock);
 
 	r = idr_pre_get(&_minor_idr, GFP_KERNEL);
 	if (!r) {
@@ -722,7 +820,7 @@ static int next_free_minor(struct mapped_device *md, unsigned int *minor)
 	*minor = m;
 
 out:
-	up(&_minor_lock);
+	mutex_unlock(&_minor_lock);
 	return r;
 }
 
@@ -747,7 +845,8 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
 		goto bad1;
 
 	memset(md, 0, sizeof(*md));
-	init_rwsem(&md->lock);
+	init_rwsem(&md->io_lock);
+	init_MUTEX(&md->suspend_lock);
 	rwlock_init(&md->map_lock);
 	atomic_set(&md->holders, 1);
 	atomic_set(&md->event_nr, 0);
@@ -760,16 +859,15 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
 	md->queue->backing_dev_info.congested_fn = dm_any_congested;
 	md->queue->backing_dev_info.congested_data = md;
 	blk_queue_make_request(md->queue, dm_request);
+	blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
 	md->queue->unplug_fn = dm_unplug_all;
 	md->queue->issue_flush_fn = dm_flush_all;
 
-	md->io_pool = mempool_create(MIN_IOS, mempool_alloc_slab,
-				     mempool_free_slab, _io_cache);
+	md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache);
  	if (!md->io_pool)
  		goto bad2;
 
-	md->tio_pool = mempool_create(MIN_IOS, mempool_alloc_slab,
-				      mempool_free_slab, _tio_cache);
+	md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache);
 	if (!md->tio_pool)
 		goto bad3;
 
@@ -784,6 +882,7 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
 	md->disk->private_data = md;
 	sprintf(md->disk->disk_name, "dm-%d", minor);
 	add_disk(md->disk);
+	format_dev_t(md->name, MKDEV(_major, minor));
 
 	atomic_set(&md->pending, 0);
 	init_waitqueue_head(&md->wait);
@@ -796,7 +895,7 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
  bad3:
 	mempool_destroy(md->io_pool);
  bad2:
-	blk_put_queue(md->queue);
+	blk_cleanup_queue(md->queue);
 	free_minor(minor);
  bad1:
 	kfree(md);
@@ -805,12 +904,18 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
 
 static void free_dev(struct mapped_device *md)
 {
-	free_minor(md->disk->first_minor);
+	unsigned int minor = md->disk->first_minor;
+
+	if (md->suspended_bdev) {
+		thaw_bdev(md->suspended_bdev, NULL);
+		bdput(md->suspended_bdev);
+	}
 	mempool_destroy(md->tio_pool);
 	mempool_destroy(md->io_pool);
 	del_gendisk(md->disk);
+	free_minor(minor);
 	put_disk(md->disk);
-	blk_put_queue(md->queue);
+	blk_cleanup_queue(md->queue);
 	kfree(md);
 }
 
@@ -825,18 +930,13 @@ static void event_callback(void *context)
 	wake_up(&md->eventq);
 }
 
-static void __set_size(struct gendisk *disk, sector_t size)
+static void __set_size(struct mapped_device *md, sector_t size)
 {
-	struct block_device *bdev;
-
-	set_capacity(disk, size);
-	bdev = bdget_disk(disk, 0);
-	if (bdev) {
-		down(&bdev->bd_inode->i_sem);
-		i_size_write(bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
-		up(&bdev->bd_inode->i_sem);
-		bdput(bdev);
-	}
+	set_capacity(md->disk, size);
+
+	mutex_lock(&md->suspended_bdev->bd_inode->i_mutex);
+	i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
+	mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex);
 }
 
 static int __bind(struct mapped_device *md, struct dm_table *t)
@@ -845,17 +945,25 @@ static int __bind(struct mapped_device *md, struct dm_table *t)
 	sector_t size;
 
 	size = dm_table_get_size(t);
-	__set_size(md->disk, size);
+
+	/*
+	 * Wipe any geometry if the size of the table changed.
+	 */
+	if (size != get_capacity(md->disk))
+		memset(&md->geometry, 0, sizeof(md->geometry));
+
+	__set_size(md, size);
 	if (size == 0)
 		return 0;
 
+	dm_table_get(t);
+	dm_table_event_callback(t, event_callback, md);
+
 	write_lock(&md->map_lock);
 	md->map = t;
+	dm_table_set_restrictions(t, q);
 	write_unlock(&md->map_lock);
 
-	dm_table_get(t);
-	dm_table_event_callback(md->map, event_callback, md);
-	dm_table_set_restrictions(t, q);
 	return 0;
 }
 
@@ -899,25 +1007,38 @@ int dm_create_with_minor(unsigned int minor, struct mapped_device **result)
 	return create_aux(minor, 1, result);
 }
 
-void *dm_get_mdptr(dev_t dev)
+static struct mapped_device *dm_find_md(dev_t dev)
 {
 	struct mapped_device *md;
-	void *mdptr = NULL;
 	unsigned minor = MINOR(dev);
 
 	if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
 		return NULL;
 
-	down(&_minor_lock);
+	mutex_lock(&_minor_lock);
 
 	md = idr_find(&_minor_idr, minor);
+	if (!md || (dm_disk(md)->first_minor != minor))
+		md = NULL;
+
+	mutex_unlock(&_minor_lock);
 
-	if (md && (dm_disk(md)->first_minor == minor))
-		mdptr = md->interface_ptr;
+	return md;
+}
 
-	up(&_minor_lock);
+struct mapped_device *dm_get_md(dev_t dev)
+{
+	struct mapped_device *md = dm_find_md(dev);
 
-	return mdptr;
+	if (md)
+		dm_get(md);
+
+	return md;
+}
+
+void *dm_get_mdptr(struct mapped_device *md)
+{
+	return md->interface_ptr;
 }
 
 void dm_set_mdptr(struct mapped_device *md, void *ptr)
@@ -932,18 +1053,18 @@ void dm_get(struct mapped_device *md)
 
 void dm_put(struct mapped_device *md)
 {
-	struct dm_table *map = dm_get_table(md);
+	struct dm_table *map;
 
 	if (atomic_dec_and_test(&md->holders)) {
-		if (!test_bit(DMF_SUSPENDED, &md->flags) && map) {
+		map = dm_get_table(md);
+		if (!dm_suspended(md)) {
 			dm_table_presuspend_targets(map);
 			dm_table_postsuspend_targets(map);
 		}
 		__unbind(md);
+		dm_table_put(map);
 		free_dev(md);
 	}
-
-	dm_table_put(map);
 }
 
 /*
@@ -966,75 +1087,55 @@ static void __flush_deferred_io(struct mapped_device *md, struct bio *c)
  */
 int dm_swap_table(struct mapped_device *md, struct dm_table *table)
 {
-	int r;
+	int r = -EINVAL;
 
-	down_write(&md->lock);
+	down(&md->suspend_lock);
 
 	/* device must be suspended */
-	if (!test_bit(DMF_SUSPENDED, &md->flags)) {
-		up_write(&md->lock);
-		return -EPERM;
-	}
+	if (!dm_suspended(md))
+		goto out;
 
 	__unbind(md);
 	r = __bind(md, table);
-	if (r)
-		return r;
 
-	up_write(&md->lock);
-	return 0;
+out:
+	up(&md->suspend_lock);
+	return r;
 }
 
 /*
  * Functions to lock and unlock any filesystem running on the
  * device.
  */
-static int __lock_fs(struct mapped_device *md)
+static int lock_fs(struct mapped_device *md)
 {
-	int error = -ENOMEM;
-
-	if (test_and_set_bit(DMF_FS_LOCKED, &md->flags))
-		return 0;
-
-	md->frozen_bdev = bdget_disk(md->disk, 0);
-	if (!md->frozen_bdev) {
-		DMWARN("bdget failed in __lock_fs");
-		goto out;
-	}
+	int r;
 
 	WARN_ON(md->frozen_sb);
 
-	md->frozen_sb = freeze_bdev(md->frozen_bdev);
+	md->frozen_sb = freeze_bdev(md->suspended_bdev);
 	if (IS_ERR(md->frozen_sb)) {
-		error = PTR_ERR(md->frozen_sb);
-		goto out_bdput;
+		r = PTR_ERR(md->frozen_sb);
+		md->frozen_sb = NULL;
+		return r;
 	}
 
+	set_bit(DMF_FROZEN, &md->flags);
+
 	/* don't bdput right now, we don't want the bdev
-	 * to go away while it is locked.  We'll bdput
-	 * in __unlock_fs
+	 * to go away while it is locked.
 	 */
 	return 0;
-
-out_bdput:
-	bdput(md->frozen_bdev);
-	md->frozen_sb = NULL;
-	md->frozen_bdev = NULL;
-out:
-	clear_bit(DMF_FS_LOCKED, &md->flags);
-	return error;
 }
 
-static void __unlock_fs(struct mapped_device *md)
+static void unlock_fs(struct mapped_device *md)
 {
-	if (!test_and_clear_bit(DMF_FS_LOCKED, &md->flags))
+	if (!test_bit(DMF_FROZEN, &md->flags))
 		return;
 
-	thaw_bdev(md->frozen_bdev, md->frozen_sb);
-	bdput(md->frozen_bdev);
-
+	thaw_bdev(md->suspended_bdev, md->frozen_sb);
 	md->frozen_sb = NULL;
-	md->frozen_bdev = NULL;
+	clear_bit(DMF_FROZEN, &md->flags);
 }
 
 /*
@@ -1044,49 +1145,49 @@ static void __unlock_fs(struct mapped_device *md)
  * dm_bind_table, dm_suspend must be called to flush any in
  * flight bios and ensure that any further io gets deferred.
  */
-int dm_suspend(struct mapped_device *md)
+int dm_suspend(struct mapped_device *md, int do_lockfs)
 {
-	struct dm_table *map;
+	struct dm_table *map = NULL;
 	DECLARE_WAITQUEUE(wait, current);
-	int error = -EINVAL;
+	struct bio *def;
+	int r = -EINVAL;
 
-	/* Flush I/O to the device. */
-	down_read(&md->lock);
-	if (test_bit(DMF_BLOCK_IO, &md->flags))
-		goto out_read_unlock;
+	down(&md->suspend_lock);
 
-	error = __lock_fs(md);
-	if (error)
-		goto out_read_unlock;
+	if (dm_suspended(md))
+		goto out;
 
 	map = dm_get_table(md);
-	if (map)
-		dm_table_presuspend_targets(map);
 
-	up_read(&md->lock);
+	/* This does not get reverted if there's an error later. */
+	dm_table_presuspend_targets(map);
+
+	md->suspended_bdev = bdget_disk(md->disk, 0);
+	if (!md->suspended_bdev) {
+		DMWARN("bdget failed in dm_suspend");
+		r = -ENOMEM;
+		goto out;
+	}
+
+	/* Flush I/O to the device. */
+	if (do_lockfs) {
+		r = lock_fs(md);
+		if (r)
+			goto out;
+	}
 
 	/*
 	 * First we set the BLOCK_IO flag so no more ios will be mapped.
-	 *
-	 * If the flag is already set we know another thread is trying to
-	 * suspend as well, so we leave the fs locked for this thread.
 	 */
-	error = -EINVAL;
-	down_write(&md->lock);
-	if (test_and_set_bit(DMF_BLOCK_IO, &md->flags)) {
-		if (map)
-			dm_table_put(map);
-		goto out_write_unlock;
-	}
+	down_write(&md->io_lock);
+	set_bit(DMF_BLOCK_IO, &md->flags);
 
 	add_wait_queue(&md->wait, &wait);
-	up_write(&md->lock);
+	up_write(&md->io_lock);
 
 	/* unplug */
-	if (map) {
+	if (map)
 		dm_table_unplug_all(map);
-		dm_table_put(map);
-	}
 
 	/*
 	 * Then we wait for the already mapped ios to
@@ -1102,63 +1203,77 @@ int dm_suspend(struct mapped_device *md)
 	}
 	set_current_state(TASK_RUNNING);
 
-	down_write(&md->lock);
+	down_write(&md->io_lock);
 	remove_wait_queue(&md->wait, &wait);
 
 	/* were we interrupted ? */
-	error = -EINTR;
-	if (atomic_read(&md->pending))
-		goto out_unfreeze;
+	r = -EINTR;
+	if (atomic_read(&md->pending)) {
+		clear_bit(DMF_BLOCK_IO, &md->flags);
+		def = bio_list_get(&md->deferred);
+		__flush_deferred_io(md, def);
+		up_write(&md->io_lock);
+		unlock_fs(md);
+		goto out;
+	}
+	up_write(&md->io_lock);
 
-	set_bit(DMF_SUSPENDED, &md->flags);
+	dm_table_postsuspend_targets(map);
 
-	map = dm_get_table(md);
-	if (map)
-		dm_table_postsuspend_targets(map);
-	dm_table_put(map);
-	up_write(&md->lock);
+	set_bit(DMF_SUSPENDED, &md->flags);
 
-	return 0;
+	r = 0;
 
-out_unfreeze:
-	/* FIXME Undo dm_table_presuspend_targets */
-	__unlock_fs(md);
-	clear_bit(DMF_BLOCK_IO, &md->flags);
-out_write_unlock:
-	up_write(&md->lock);
-	return error;
+out:
+	if (r && md->suspended_bdev) {
+		bdput(md->suspended_bdev);
+		md->suspended_bdev = NULL;
+	}
 
-out_read_unlock:
-	up_read(&md->lock);
-	return error;
+	dm_table_put(map);
+	up(&md->suspend_lock);
+	return r;
 }
 
 int dm_resume(struct mapped_device *md)
 {
+	int r = -EINVAL;
 	struct bio *def;
-	struct dm_table *map = dm_get_table(md);
+	struct dm_table *map = NULL;
 
-	down_write(&md->lock);
-	if (!map ||
-	    !test_bit(DMF_SUSPENDED, &md->flags) ||
-	    !dm_table_get_size(map)) {
-		up_write(&md->lock);
-		dm_table_put(map);
-		return -EINVAL;
-	}
+	down(&md->suspend_lock);
+	if (!dm_suspended(md))
+		goto out;
+
+	map = dm_get_table(md);
+	if (!map || !dm_table_get_size(map))
+		goto out;
 
 	dm_table_resume_targets(map);
-	clear_bit(DMF_SUSPENDED, &md->flags);
+
+	down_write(&md->io_lock);
 	clear_bit(DMF_BLOCK_IO, &md->flags);
 
 	def = bio_list_get(&md->deferred);
 	__flush_deferred_io(md, def);
-	up_write(&md->lock);
-	__unlock_fs(md);
+	up_write(&md->io_lock);
+
+	unlock_fs(md);
+
+	bdput(md->suspended_bdev);
+	md->suspended_bdev = NULL;
+
+	clear_bit(DMF_SUSPENDED, &md->flags);
+
 	dm_table_unplug_all(map);
+
+	r = 0;
+
+out:
 	dm_table_put(map);
+	up(&md->suspend_lock);
 
-	return 0;
+	return r;
 }
 
 /*-----------------------------------------------------------------
@@ -1192,6 +1307,7 @@ int dm_suspended(struct mapped_device *md)
 static struct block_device_operations dm_blk_dops = {
 	.open = dm_blk_open,
 	.release = dm_blk_close,
+	.getgeo = dm_blk_getgeo,
 	.owner = THIS_MODULE
 };