btrfs: fix a bogus warning when converting only data or metadata

If your filesystem has, eg, data:raid0 metadata:raid1, and you run "btrfs balance -dconvert=raid1", the meta.target field will be uninitialized. That's otherwise ok, as it's unused except for this warning. Thus, let's use the existing set of raid levels for the comparison. As a side effect, non-convert balances will now nag about data>metadata. Signed-off-by: Adam Borowski <[email protected]> Reviewed-by: Liu Bo <[email protected]> Signed-off-by: David Sterba <[email protected]>
tadfisher · Apr 18, 2017 · 1450612 · 1450612
1 parent aeea4c1
commit 1450612
Showing 1 changed file with 9 additions and 3 deletions.
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
@@ -3755,6 +3755,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
 		  struct btrfs_ioctl_balance_args *bargs)
 {
 	struct btrfs_fs_info *fs_info = bctl->fs_info;
+	u64 meta_target, data_target;
 	u64 allowed;
 	int mixed = 0;
 	int ret;
@@ -3851,11 +3852,16 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
 		}
 	} while (read_seqretry(&fs_info->profiles_lock, seq));
 
-	if (btrfs_get_num_tolerated_disk_barrier_failures(bctl->meta.target) <
-		btrfs_get_num_tolerated_disk_barrier_failures(bctl->data.target)) {
+	/* if we're not converting, the target field is uninitialized */
+	meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
+		bctl->meta.target : fs_info->avail_metadata_alloc_bits;
+	data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
+		bctl->data.target : fs_info->avail_data_alloc_bits;
+	if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) <
+		btrfs_get_num_tolerated_disk_barrier_failures(data_target)) {
 		btrfs_warn(fs_info,
 			   "metadata profile 0x%llx has lower redundancy than data profile 0x%llx",
-			   bctl->meta.target, bctl->data.target);
+			   meta_target, data_target);
 	}
 
 	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {