1 files changed, 9 insertions, 4 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 28addea5b0f2..bcc0acda8691 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2650,6 +2650,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
 {
         struct btrfs_fs_info *fs_info = bctl->fs_info;
         u64 allowed;
+        int mixed = 0;
         int ret;
 
         if (btrfs_fs_closing(fs_info) ||
@@ -2659,13 +2660,16 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
                 goto out;
         }
 
+        allowed = btrfs_super_incompat_flags(fs_info->super_copy);
+        if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+                mixed = 1;
+
         /*
          * In case of mixed groups both data and meta should be picked,
          * and identical options should be given for both of them.
          */
-        allowed = btrfs_super_incompat_flags(fs_info->super_copy);
-        if ((allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
-            (bctl->flags & (BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA))) {
+        allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
+        if (mixed && (bctl->flags & allowed)) {
                 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
                     !(bctl->flags & BTRFS_BALANCE_METADATA) ||
                     memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
@@ -2713,7 +2717,8 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
                 goto out;
         }
 
-        if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+        /* allow dup'ed data chunks only in mixed mode */
+        if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
             (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
                 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
                 ret = -EINVAL;