From 2c45c9b8b20f35151659ac289c6508149b63e83e Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Thu, 31 Mar 2011 23:37:23 -0400
Subject: [PATCH] dm integrity code cleanup

---
 block/blk-integrity.c  |   11 +++++++++--
 drivers/md/dm-table.c  |   48 ++++++++++++++++++++----------------------------
 include/linux/blkdev.h |    8 +-------
 3 files changed, 30 insertions(+), 37 deletions(-)

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index a36186d..129b9e2 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -30,8 +30,7 @@
 
 static struct kmem_cache *integrity_cachep;
 
-const char bi_unsupported_name[] = "unsupported";
-EXPORT_SYMBOL_GPL(bi_unsupported_name);
+static const char *bi_unsupported_name = "unsupported";
 
 /**
  * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
@@ -361,6 +360,14 @@ static struct kobj_type integrity_ktype = {
 	.release	= blk_integrity_release,
 };
 
+bool blk_integrity_is_initialized(struct gendisk *disk)
+{
+	struct blk_integrity *bi = blk_get_integrity(disk);
+
+	return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
+}
+EXPORT_SYMBOL(blk_integrity_is_initialized);
+
 /**
  * blk_integrity_register - Register a gendisk as being integrity-capable
  * @disk:	struct gendisk pointer to make integrity-aware
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 39ee315..5ec4bf5 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -938,14 +938,12 @@ static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
 	struct list_head *devices = dm_table_get_devices(t);
 	struct dm_dev_internal *dd = NULL;
 	struct gendisk *prev_disk = NULL, *template_disk = NULL;
-	struct blk_integrity *bi = NULL;
 
 	list_for_each_entry(dd, devices, list) {
 		template_disk = dd->dm_dev.bdev->bd_disk;
-		bi = blk_get_integrity(template_disk);
-		if (!bi)
+		if (!blk_get_integrity(template_disk))
 			goto no_integrity;
-		if (!match_all && !blk_integrity_is_initialized(bi))
+		if (!match_all && !blk_integrity_is_initialized(template_disk))
 			continue; /* skip uninitialized profiles */
 		else if (prev_disk &&
 			 blk_integrity_compare(prev_disk, template_disk) < 0) {
@@ -977,37 +975,31 @@ no_integrity:
 static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
 {
 	struct gendisk *template_disk = NULL;
-	struct blk_integrity *template_bi = NULL, *dm_bi = NULL;
 
 	template_disk = dm_table_get_integrity_disk(t, false);
-	if (template_disk) {
-		/*
-		 * If DM device already has an initalized integrity
-		 * profile the new profile should not conflict.
-		 */
-		dm_bi = blk_get_integrity(dm_disk(md));
-		template_bi = blk_get_integrity(template_disk);
-		if (blk_integrity_is_initialized(dm_bi)) {
-			if (blk_integrity_is_initialized(template_bi) &&
-			    blk_integrity_compare(dm_disk(md), template_disk) < 0) {
-				DMWARN("%s: existing integrity conflict: "
-				       "%s mismatch",
-				       dm_device_name(t->md),
-				       template_disk->disk_name);
-				return 1;
-			}
-
-			/*
-			 * Avoid clearing an existing integrity profile
-			 */
-			t->integrity_supported = 1;
-			return 0;
-		}
+	if (!template_disk)
+		return 0;
 
+	if (!blk_integrity_is_initialized(dm_disk(md))) {
 		t->integrity_supported = 1;
 		return blk_integrity_register(dm_disk(md), NULL);
 	}
 
+	/*
+	 * If DM device already has an initalized integrity
+	 * profile the new profile should not conflict.
+	 */
+	if (blk_integrity_is_initialized(template_disk) &&
+	    blk_integrity_compare(dm_disk(md), template_disk) < 0) {
+		DMWARN("%s: existing integrity conflict: "
+		       "%s mismatch",
+		       dm_device_name(t->md),
+		       template_disk->disk_name);
+		return 1;
+	}
+
+	/* Preserve existing initialized integrity profile */
+	t->integrity_supported = 1;
 	return 0;
 }
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 405b93b..32176cc 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1206,6 +1206,7 @@ struct blk_integrity {
 	struct kobject		kobj;
 };
 
+extern bool blk_integrity_is_initialized(struct gendisk *);
 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
 extern void blk_integrity_unregister(struct gendisk *);
 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
@@ -1248,13 +1249,6 @@ queue_max_integrity_segments(struct request_queue *q)
 	return q->limits.max_integrity_segments;
 }
 
-extern const char bi_unsupported_name[];  /* = "unsupported" */
-
-static inline bool blk_integrity_is_initialized(struct blk_integrity *bi)
-{
-	return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
-}
-
 #else /* CONFIG_BLK_DEV_INTEGRITY */
 
 #define blk_integrity_rq(rq)			(0)