btrfs-progs: introduce helper to get allowed profiles for a given device number

Use the raid table helper to avoid hard coding profiles for the given
number of devices in test_num_disk_vs_raid.

Signed-off-by: David Sterba <dsterba@suse.com>

common/utils.c

@@ -579,25 +579,10 @@ int get_fsid(const char *path, u8 *fsid, int silent)
 int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
 	u64 dev_cnt, int mixed, int ssd)
 {
-	u64 allowed = 0;
+	u64 allowed;
 	u64 profile = metadata_profile | data_profile;
 
-	switch (dev_cnt) {
+	allowed = btrfs_bg_flags_for_device_num(dev_cnt);
-	default:
-	case 4:
-		allowed |= BTRFS_BLOCK_GROUP_RAID10;
-		allowed |= BTRFS_BLOCK_GROUP_RAID10 | BTRFS_BLOCK_GROUP_RAID1C4;
-		/* fallthrough */
-	case 3:
-		allowed |= BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID1C3;
-		/* fallthrough */
-	case 2:
-		allowed |= BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
-			BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID10;
-		/* fallthrough */
-	case 1:
-		allowed |= BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0;
-	}
 
 	if (dev_cnt > 1 && profile & BTRFS_BLOCK_GROUP_DUP) {
 		warning("DUP is not recommended on filesystem with multiple devices");

kernel-shared/volumes.c

@@ -245,6 +245,19 @@ int btrfs_bg_type_to_sub_stripes(u64 flags)
 	return btrfs_raid_array[index].sub_stripes;
 }
 
+u64 btrfs_bg_flags_for_device_num(int number)
+{
+	int i;
+	u64 ret = 0;
+
+	for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++) {
+		if (number >= btrfs_raid_array[i].devs_min)
+			ret |= btrfs_raid_array[i].bg_flag;
+	}
+
+	return ret;
+}
+
 static inline int nr_data_stripes(struct map_lookup *map)
 {
 	return map->num_stripes - btrfs_bg_type_to_nparity(map->type);

kernel-shared/volumes.h

@@ -312,5 +312,6 @@ int btrfs_bg_type_to_devs_min(u64 flags);
 int btrfs_bg_type_to_ncopies(u64 flags);
 int btrfs_bg_type_to_nparity(u64 flags);
 int btrfs_bg_type_to_sub_stripes(u64 flags);
+u64 btrfs_bg_flags_for_device_num(int number);
 
 #endif