apply same duplication safegurads during backup creation

Author: UriHerrera

debian/changelog

@@ -1,3 +1,9 @@
+nuts (2.2.6) nitrux; urgency=medium
+
+  * Ensure backup always follows the active root and indicate potentially confusing environments.
+
+ -- Uri Herrera <[email protected]>  Sub, 29 Dec 2025 11:37:00 -0500
+
 nuts (2.2.5) nitrux; urgency=medium
 
   * Deprecate the restore command and removed related code.

usr/bin/nuts

@@ -259,28 +259,50 @@ done
             # -- This backup is created outside of the chroot because xfsdump relies on /etc/mtab, and that file is unavailable when using overlayroot-chroot.
             # -- Since the XFS backup is a "full-backup" (level 0), it won't support incremental updates.
 
-            ROOT_PARTITION=$(findfs LABEL=NX_ROOT)
-            ROOT_PARTITION_LABEL=$(blkid -o value -s LABEL "$ROOT_PARTITION")
-            ROOT_PARTITION_FS=$(blkid -o value -s TYPE "$ROOT_PARTITION")
-            XFS_BACKUP_FILE="$NUTS_DIR_XFS/xfs-backup.xfs"
-            COMPRESSED_XFS_BACKUP="$XFS_BACKUP_FILE.zst"
-            ZSTD_COMP_THREADS=$(nproc)
+            ROOT_PARTITION=$(findmnt -n -o SOURCE /media/root-ro 2>/dev/null || true)
+
+            if [ -z "$ROOT_PARTITION" ]; then
+                ROOT_PARTITION=$(findmnt -n -o SOURCE / 2>/dev/null || true)
+            fi
+
+            if [ -z "$ROOT_PARTITION" ]; then
+                puts_error "Could not resolve the root device from mount points. Quitting."
+                exit 1
+            fi
+
+            ROOT_PARTITION_LABEL=$(blkid -o value -s LABEL "$ROOT_PARTITION" 2>/dev/null || true)
+            ROOT_PARTITION_FS=$(blkid -o value -s TYPE "$ROOT_PARTITION" 2>/dev/null || true)
+
+            if [ -z "$ROOT_PARTITION_LABEL" ]; then
+                puts_error "Resolved root device $ROOT_PARTITION has no label, quitting."
+                exit 1
+            fi
 
             if [[ "$ROOT_PARTITION_FS" != "xfs" ]]; then
-                puts_error "The filesystem of $ROOT_PARTITION_LABEL is not XFS, quitting."
+                puts_error "The filesystem of $ROOT_PARTITION_LABEL ($ROOT_PARTITION) is not XFS, quitting."
                 exit 1
             fi
 
+            LABEL_COUNT=$(blkid -o device -t LABEL="$ROOT_PARTITION_LABEL" 2>/dev/null | wc -l)
+
+            if [ "$LABEL_COUNT" -gt 1 ]; then
+                puts_warning "Detected $LABEL_COUNT devices with label $ROOT_PARTITION_LABEL; backing up active root device $ROOT_PARTITION."
+            fi
+
+            XFS_BACKUP_FILE="$NUTS_DIR_XFS/xfs-backup.xfs"
+            COMPRESSED_XFS_BACKUP="$XFS_BACKUP_FILE.zst"
+            ZSTD_COMP_THREADS=$(nproc)
+
             if [[ -f "$COMPRESSED_XFS_BACKUP" ]]; then  
                 puts_info "Backup of $ROOT_PARTITION_LABEL found, skipping..."
             else
                 puts_warning "Backup of $ROOT_PARTITION_LABEL not found, creating it..."
-                
+
                 xfsdump -l0 -L "Nitrux_Update_Tool_System-XFS_Backup" -M "NX_BAK-Vol-1" -f "$XFS_BACKUP_FILE" "$ROOT_PARTITION" > /dev/null 2>&1 &
                 spinner "$!"
-                
+
                 puts_info "Using $ZSTD_COMP_THREADS threads for backup compression, please wait..."
-                
+
                 zstd -T"$ZSTD_COMP_THREADS" -3 "$XFS_BACKUP_FILE" -o "$COMPRESSED_XFS_BACKUP"
 
                 rm -f "$XFS_BACKUP_FILE"