btrfs: Move btrfs_raid_array to public

This array is used to record attributes of each raid type,
make it public, and many functions will benifit with this array.

For example, num_tolerated_disk_barrier_failures(), we can
avoid complex conditions in this function, and get raid attribute
simply by accessing above array.

It can also make code logic simple, reduce duplication code, and
increase maintainability.
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -42,6 +42,75 @@
 #include "dev-replace.h"
 #include "sysfs.h"
 
+const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
+	[BTRFS_RAID_RAID10] = {
+		.sub_stripes	= 2,
+		.dev_stripes	= 1,
+		.devs_max	= 0,	/* 0 == as many as possible */
+		.devs_min	= 4,
+		.devs_increment	= 2,
+		.ncopies	= 2,
+	},
+	[BTRFS_RAID_RAID1] = {
+		.sub_stripes	= 1,
+		.dev_stripes	= 1,
+		.devs_max	= 2,
+		.devs_min	= 2,
+		.devs_increment	= 2,
+		.ncopies	= 2,
+	},
+	[BTRFS_RAID_DUP] = {
+		.sub_stripes	= 1,
+		.dev_stripes	= 2,
+		.devs_max	= 1,
+		.devs_min	= 1,
+		.devs_increment	= 1,
+		.ncopies	= 2,
+	},
+	[BTRFS_RAID_RAID0] = {
+		.sub_stripes	= 1,
+		.dev_stripes	= 1,
+		.devs_max	= 0,
+		.devs_min	= 2,
+		.devs_increment	= 1,
+		.ncopies	= 1,
+	},
+	[BTRFS_RAID_SINGLE] = {
+		.sub_stripes	= 1,
+		.dev_stripes	= 1,
+		.devs_max	= 1,
+		.devs_min	= 1,
+		.devs_increment	= 1,
+		.ncopies	= 1,
+	},
+	[BTRFS_RAID_RAID5] = {
+		.sub_stripes	= 1,
+		.dev_stripes	= 1,
+		.devs_max	= 0,
+		.devs_min	= 2,
+		.devs_increment	= 1,
+		.ncopies	= 2,
+	},
+	[BTRFS_RAID_RAID6] = {
+		.sub_stripes	= 1,
+		.dev_stripes	= 1,
+		.devs_max	= 0,
+		.devs_min	= 3,
+		.devs_increment	= 1,
+		.ncopies	= 3,
+	},
+};
+
+const u64 const btrfs_raid_group[BTRFS_NR_RAID_TYPES] = {
+	[BTRFS_RAID_RAID10] = BTRFS_BLOCK_GROUP_RAID10,
+	[BTRFS_RAID_RAID1]  = BTRFS_BLOCK_GROUP_RAID1,
+	[BTRFS_RAID_DUP]    = BTRFS_BLOCK_GROUP_DUP,
+	[BTRFS_RAID_RAID0]  = BTRFS_BLOCK_GROUP_RAID0,
+	[BTRFS_RAID_SINGLE] = 0,
+	[BTRFS_RAID_RAID5]  = BTRFS_BLOCK_GROUP_RAID5,
+	[BTRFS_RAID_RAID6]  = BTRFS_BLOCK_GROUP_RAID6,
+};
+
 static int init_first_rw_device(struct btrfs_trans_handle *trans,
 				struct btrfs_root *root,
 				struct btrfs_device *device);
@@ -4285,65 +4354,6 @@ static int btrfs_cmp_device_info(const void *a, const void *b)
 	return 0;
 }
 
-static const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
-	[BTRFS_RAID_RAID10] = {
-		.sub_stripes	= 2,
-		.dev_stripes	= 1,
-		.devs_max	= 0,	/* 0 == as many as possible */
-		.devs_min	= 4,
-		.devs_increment	= 2,
-		.ncopies	= 2,
-	},
-	[BTRFS_RAID_RAID1] = {
-		.sub_stripes	= 1,
-		.dev_stripes	= 1,
-		.devs_max	= 2,
-		.devs_min	= 2,
-		.devs_increment	= 2,
-		.ncopies	= 2,
-	},
-	[BTRFS_RAID_DUP] = {
-		.sub_stripes	= 1,
-		.dev_stripes	= 2,
-		.devs_max	= 1,
-		.devs_min	= 1,
-		.devs_increment	= 1,
-		.ncopies	= 2,
-	},
-	[BTRFS_RAID_RAID0] = {
-		.sub_stripes	= 1,
-		.dev_stripes	= 1,
-		.devs_max	= 0,
-		.devs_min	= 2,
-		.devs_increment	= 1,
-		.ncopies	= 1,
-	},
-	[BTRFS_RAID_SINGLE] = {
-		.sub_stripes	= 1,
-		.dev_stripes	= 1,
-		.devs_max	= 1,
-		.devs_min	= 1,
-		.devs_increment	= 1,
-		.ncopies	= 1,
-	},
-	[BTRFS_RAID_RAID5] = {
-		.sub_stripes	= 1,
-		.dev_stripes	= 1,
-		.devs_max	= 0,
-		.devs_min	= 2,
-		.devs_increment	= 1,
-		.ncopies	= 2,
-	},
-	[BTRFS_RAID_RAID6] = {
-		.sub_stripes	= 1,
-		.dev_stripes	= 1,
-		.devs_max	= 0,
-		.devs_min	= 3,
-		.devs_increment	= 1,
-		.ncopies	= 3,
-	},
-};
-
 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
 {
 	/* TODO allow them to set a preferred stripe size */

fs/btrfs/volumes.h

@@ -338,6 +338,10 @@ struct btrfs_raid_attr {
 	int ncopies;		/* how many copies to data has */
 };
 
+extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
+
+extern const u64 btrfs_raid_group[BTRFS_NR_RAID_TYPES];
+
 struct map_lookup {
 	u64 type;
 	int io_align;