btrfs: move btrfs_raid_type_names values to btrfs_raid_attr table

Add a new member struct btrfs_raid_attr::raid_name so that
btrfs_raid_array can maintain the name of the raid type, and so we can
drop btrfs_raid_type_names.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent-tree.c

@@ -7380,24 +7380,6 @@ wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 	return ret;
 }
 
-static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = {
-	[BTRFS_RAID_RAID10]	= "raid10",
-	[BTRFS_RAID_RAID1]	= "raid1",
-	[BTRFS_RAID_DUP]	= "dup",
-	[BTRFS_RAID_RAID0]	= "raid0",
-	[BTRFS_RAID_SINGLE]	= "single",
-	[BTRFS_RAID_RAID5]	= "raid5",
-	[BTRFS_RAID_RAID6]	= "raid6",
-};
-
-static const char *get_raid_name(enum btrfs_raid_types type)
-{
-	if (type >= BTRFS_NR_RAID_TYPES)
-		return NULL;
-
-	return btrfs_raid_type_names[type];
-}
-
 enum btrfs_loop_type {
 	LOOP_CACHING_NOWAIT = 0,
 	LOOP_CACHING_WAIT = 1,

fs/btrfs/volumes.c

@@ -40,6 +40,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 1,
 		.devs_increment	= 2,
 		.ncopies	= 2,
+		.raid_name	= "raid10",
 	},
 	[BTRFS_RAID_RAID1] = {
 		.sub_stripes	= 1,
@@ -49,6 +50,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 1,
 		.devs_increment	= 2,
 		.ncopies	= 2,
+		.raid_name	= "raid1",
 	},
 	[BTRFS_RAID_DUP] = {
 		.sub_stripes	= 1,
@@ -58,6 +60,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 0,
 		.devs_increment	= 1,
 		.ncopies	= 2,
+		.raid_name	= "dup",
 	},
 	[BTRFS_RAID_RAID0] = {
 		.sub_stripes	= 1,
@@ -67,6 +70,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 0,
 		.devs_increment	= 1,
 		.ncopies	= 1,
+		.raid_name	= "raid0",
 	},
 	[BTRFS_RAID_SINGLE] = {
 		.sub_stripes	= 1,
@@ -76,6 +80,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 0,
 		.devs_increment	= 1,
 		.ncopies	= 1,
+		.raid_name	= "single",
 	},
 	[BTRFS_RAID_RAID5] = {
 		.sub_stripes	= 1,
@@ -85,6 +90,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 1,
 		.devs_increment	= 1,
 		.ncopies	= 2,
+		.raid_name	= "raid5",
 	},
 	[BTRFS_RAID_RAID6] = {
 		.sub_stripes	= 1,
@@ -94,9 +100,18 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.tolerated_failures = 2,
 		.devs_increment	= 1,
 		.ncopies	= 3,
+		.raid_name	= "raid6",
 	},
 };
 
+const char *get_raid_name(enum btrfs_raid_types type)
+{
+	if (type >= BTRFS_NR_RAID_TYPES)
+		return NULL;
+
+	return btrfs_raid_array[type].raid_name;
+}
+
 const u64 btrfs_raid_group[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID10] = BTRFS_BLOCK_GROUP_RAID10,
 	[BTRFS_RAID_RAID1]  = BTRFS_BLOCK_GROUP_RAID1,

fs/btrfs/volumes.h

@@ -329,6 +329,7 @@ struct btrfs_raid_attr {
 	int tolerated_failures; /* max tolerated fail devs */
 	int devs_increment;	/* ndevs has to be a multiple of this */
 	int ncopies;		/* how many copies to data has */
+	const char raid_name[8]; /* name of the raid */
 };
 
 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
@@ -550,6 +551,8 @@ static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags)
 	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
 }
 
+const char *get_raid_name(enum btrfs_raid_types type);
+
 void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info);
 void btrfs_update_commit_device_bytes_used(struct btrfs_transaction *trans);