system_setup/install.sh

@@ -345,14 +345,14 @@ if [[ "$MODE" == "shrink" ]]; then
     echo "  After shrink      : ${CURR_START} MiB – ${NEW_END} MiB  (filesystem: ${NEW_FS_MIB} MiB)"
     echo "  New OEMDRV        : ${OEMDRV_START} MiB – ${OEMDRV_END} MiB  (${SHRINK_MIB} MiB)"
 
+    if [[ "$S_FS" == "ext4" ]]; then
+        # ext4 requires offline resize — unmount first
         if [[ "$S_MNT" != "-" && -n "$S_MNT" ]]; then
             info "Unmounting $S_DEV from $S_MNT..."
             ORIG_MNT="$S_MNT"
             umount "$S_DEV" || die "Cannot unmount $S_DEV. Close all open files and try again."
             WAS_MOUNTED=1
         fi
-
-    if [[ "$S_FS" == "ext4" ]]; then
         info "Running e2fsck on $S_DEV..."
         e2fsck -f "$S_DEV" || die "e2fsck found errors on $S_DEV. Fix them before retrying."
 
@@ -360,7 +360,13 @@ if [[ "$MODE" == "shrink" ]]; then
         resize2fs "$S_DEV" "${NEW_FS_MIB}M" || die "resize2fs failed."
 
     elif [[ "$S_FS" == "btrfs" ]]; then
+        # btrfs supports online resize — use existing mount point if available,
+        # otherwise mount temporarily
         info "Shrinking btrfs filesystem on $S_DEV to ${NEW_FS_MIB} MiB..."
+        if [[ "$S_MNT" != "-" && -n "$S_MNT" ]]; then
+            btrfs filesystem resize "${NEW_FS_MIB}m" "$S_MNT" \
+                || die "btrfs filesystem resize failed."
+        else
             TMP_MNT=$(mktemp -d /tmp/oemdrv_btrfs.XXXXXX)
             mount "$S_DEV" "$TMP_MNT" || { rmdir "$TMP_MNT"; die "Cannot mount $S_DEV for btrfs resize."; }
             btrfs filesystem resize "${NEW_FS_MIB}m" "$TMP_MNT" \
@@ -368,6 +374,7 @@ if [[ "$MODE" == "shrink" ]]; then
             sync
             umount "$TMP_MNT" && rmdir "$TMP_MNT"
         fi
+    fi
 
     info "Shrinking partition $S_PNUM to ${NEW_END} MiB in partition table..."
     parted -s "$S_DISK" resizepart "$S_PNUM" "${NEW_END}MiB" \