diff --git a/libbtrfs/ioctl.h b/libbtrfs/ioctl.h
index 686c1035..f19695e3 100644
--- a/libbtrfs/ioctl.h
+++ b/libbtrfs/ioctl.h
@@ -71,10 +71,10 @@ BUILD_ASSERT(sizeof(struct btrfs_ioctl_vol_args) == 4096);
 
 struct btrfs_qgroup_limit {
 	__u64	flags;
-	__u64	max_rfer;
-	__u64	max_excl;
-	__u64	rsv_rfer;
-	__u64	rsv_excl;
+	__u64	max_referenced;
+	__u64	max_exclusive;
+	__u64	rsv_referenced;
+	__u64	rsv_exclusive;
 };
 BUILD_ASSERT(sizeof(struct btrfs_qgroup_limit) == 40);
 
@@ -192,6 +192,7 @@ BUILD_ASSERT(sizeof(struct btrfs_ioctl_dev_replace_status_params) == 48);
 #define BTRFS_IOCTL_DEV_REPLACE_CMD_START			0
 #define BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS			1
 #define BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL			2
+#define BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_RESULT		-1
 #define BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR			0
 #define BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED		1
 #define BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED		2
@@ -934,6 +935,38 @@ enum btrfs_err_code {
 	BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET,
 };
 
+/* An error code to error string mapping for the kernel
+*  error codes
+*/
+static inline char *btrfs_err_str(enum btrfs_err_code err_code)
+{
+	switch (err_code) {
+		case BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET:
+			return "unable to go below two devices on raid1";
+		case BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET:
+			return "unable to go below three devices on raid1c3";
+		case BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET:
+			return "unable to go below four devices on raid1c4";
+		case BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET:
+			return "unable to go below four/two devices on raid10";
+		case BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET:
+			return "unable to go below two devices on raid5";
+		case BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET:
+			return "unable to go below three devices on raid6";
+		case BTRFS_ERROR_DEV_TGT_REPLACE:
+			return "unable to remove the dev_replace target dev";
+		case BTRFS_ERROR_DEV_MISSING_NOT_FOUND:
+			return "no missing devices found to remove";
+		case BTRFS_ERROR_DEV_ONLY_WRITABLE:
+			return "unable to remove the only writeable device";
+		case BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS:
+			return "add/delete/balance/replace/resize operation "
+				"in progress";
+		default:
+			return NULL;
+	}
+}
+
 #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
 				   struct btrfs_ioctl_vol_args)
 #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \