[PATCH] dm: add exports

Move definitions of core device-mapper functions for manipulating mapped
devices and their tables to <linux/device-mapper.h> advertising their
availability for use elsewhere in the kernel.

Protect the contents of device-mapper.h with ifdef __KERNEL__.  And throw
in a few formatting clean-ups and extra comments.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 59bf797..952c49c 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -50,9 +50,9 @@
 
 union map_info *dm_get_mapinfo(struct bio *bio)
 {
-        if (bio && bio->bi_private)
-                return &((struct target_io *)bio->bi_private)->info;
-        return NULL;
+	if (bio && bio->bi_private)
+		return &((struct target_io *)bio->bi_private)->info;
+	return NULL;
 }
 
 #define MINOR_ALLOCED ((void *)-1)
@@ -474,8 +474,8 @@
 	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, 
+		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);
@@ -1042,7 +1042,7 @@
 	md = idr_find(&_minor_idr, minor);
 	if (md && (md == MINOR_ALLOCED ||
 		   (dm_disk(md)->first_minor != minor) ||
-	           test_bit(DMF_FREEING, &md->flags))) {
+		   test_bit(DMF_FREEING, &md->flags))) {
 		md = NULL;
 		goto out;
 	}