btrfs: raid56: allow the exact minimum number of devices for balance convert

[sfrench/cifs-2.6.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1c2a6e4b39da7205a17f8c31ae0971a8abeed821..10f7de0cc7e68e7689163797676dd893fa7caf54 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4080,11 +4080,12 @@ int btrfs_balance(struct btrfs_fs_info *fs_info,
        allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE | BTRFS_BLOCK_GROUP_DUP;
        if (num_devices > 1)
                allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
-       if (num_devices > 2)
+       if (num_devices >= 2)
                allowed |= BTRFS_BLOCK_GROUP_RAID5;
+       if (num_devices >= 3)
+               allowed |= BTRFS_BLOCK_GROUP_RAID6;
        if (num_devices > 3)
-               allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
-                           BTRFS_BLOCK_GROUP_RAID6);
+               allowed |= BTRFS_BLOCK_GROUP_RAID10;
        if (validate_convert_profile(&bctl->data, allowed)) {
                int index = btrfs_bg_flags_to_raid_index(bctl->data.target);
 
@@ -5328,8 +5329,7 @@ static inline int btrfs_chunk_max_errors(struct map_lookup *map)
 
        if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
                         BTRFS_BLOCK_GROUP_RAID10 |
-                        BTRFS_BLOCK_GROUP_RAID5 |
-                        BTRFS_BLOCK_GROUP_DUP)) {
+                        BTRFS_BLOCK_GROUP_RAID5)) {
                max_errors = 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
                max_errors = 2;