btrfs: move btrfs_raid_mindev_errorvalues to btrfs_raid_attr table

Add a new member struct btrfs_raid_attr::mindev_error so that
btrfs_raid_array can maintain the error code to return if the minimum
number of devices condition is not met while trying to delete a device
in the given raid. And so we can drop btrfs_raid_mindev_error.

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

fs/btrfs/volumes.c

@@ -42,6 +42,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.ncopies	= 2,
 		.raid_name	= "raid10",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID10,
+		.mindev_error	= BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
 	},
 	[BTRFS_RAID_RAID1] = {
 		.sub_stripes	= 1,
@@ -53,6 +54,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.ncopies	= 2,
 		.raid_name	= "raid1",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID1,
+		.mindev_error	= BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
 	},
 	[BTRFS_RAID_DUP] = {
 		.sub_stripes	= 1,
@@ -64,6 +66,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.ncopies	= 2,
 		.raid_name	= "dup",
 		.bg_flag	= BTRFS_BLOCK_GROUP_DUP,
+		.mindev_error	= 0,
 	},
 	[BTRFS_RAID_RAID0] = {
 		.sub_stripes	= 1,
@@ -75,6 +78,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.ncopies	= 1,
 		.raid_name	= "raid0",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID0,
+		.mindev_error	= 0,
 	},
 	[BTRFS_RAID_SINGLE] = {
 		.sub_stripes	= 1,
@@ -86,6 +90,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.ncopies	= 1,
 		.raid_name	= "single",
 		.bg_flag	= 0,
+		.mindev_error	= 0,
 	},
 	[BTRFS_RAID_RAID5] = {
 		.sub_stripes	= 1,
@@ -97,6 +102,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.ncopies	= 2,
 		.raid_name	= "raid5",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID5,
+		.mindev_error	= BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
 	},
 	[BTRFS_RAID_RAID6] = {
 		.sub_stripes	= 1,
@@ -108,6 +114,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 		.ncopies	= 3,
 		.raid_name	= "raid6",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID6,
+		.mindev_error	= BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
 	},
 };
 
@@ -119,21 +126,6 @@ const char *get_raid_name(enum btrfs_raid_types type)
 	return btrfs_raid_array[type].raid_name;
 }
 
-/*
- * Table to convert BTRFS_RAID_* to the error code if minimum number of devices
- * condition is not met. Zero means there's no corresponding
- * BTRFS_ERROR_DEV_*_NOT_MET value.
- */
-const int btrfs_raid_mindev_error[BTRFS_NR_RAID_TYPES] = {
-	[BTRFS_RAID_RAID10] = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
-	[BTRFS_RAID_RAID1]  = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
-	[BTRFS_RAID_DUP]    = 0,
-	[BTRFS_RAID_RAID0]  = 0,
-	[BTRFS_RAID_SINGLE] = 0,
-	[BTRFS_RAID_RAID5]  = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
-	[BTRFS_RAID_RAID6]  = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
-};
-
 static int init_first_rw_device(struct btrfs_trans_handle *trans,
 				struct btrfs_fs_info *fs_info);
 static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info);
@@ -1900,7 +1892,7 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
 			continue;
 
 		if (num_devices < btrfs_raid_array[i].devs_min) {
-			int ret = btrfs_raid_mindev_error[i];
+			int ret = btrfs_raid_array[i].mindev_error;
 
 			if (ret)
 				return ret;

fs/btrfs/volumes.h

@@ -329,12 +329,12 @@ 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 */
+	int mindev_error;	/* error code if min devs requisite is unmet */
 	const char raid_name[8]; /* name of the raid */
 	u64 bg_flag;		/* block group flag of the raid */
 };
 
 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
-extern const int btrfs_raid_mindev_error[BTRFS_NR_RAID_TYPES];
 
 struct map_lookup {
 	u64 type;