Create btrfs-fix-default.sh

Author: pheiduck

timeshift/btrfs-fix-default.sh

@@ -0,0 +1,38 @@
+### File: /usr/local/bin/btrfs-fix-default.sh
+
+#!/bin/bash
+set -euo pipefail
+
+EXPECTED_PATH="@"
+LOG="/var/log/btrfs-fix-default.log"
+
+log() { echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" | tee -a "$LOG"; }
+
+# Get current default subvolume path
+CURRENT=$(btrfs subvolume get-default / | awk '{print $NF}')
+
+if [[ "$CURRENT" == "$EXPECTED_PATH" ]]; then
+    log "Btrfs default subvolume is correct ($CURRENT). Nothing to do."
+    exit 0
+fi
+
+log "Btrfs default is '$CURRENT', expected '$EXPECTED_PATH'. Fixing..."
+
+# Find ID of @ subvolume
+SUBVOL_ID=$(btrfs subvolume list / | awk '/ path @$/ {print $2}')
+
+if [[ -z "$SUBVOL_ID" ]]; then
+    log "ERROR: Could not find subvolume '@'. Aborting."
+    exit 1
+fi
+
+log "Setting default subvolume to ID $SUBVOL_ID (@)..."
+btrfs subvolume set-default "$SUBVOL_ID" /
+
+log "Rebuilding initramfs..."
+mkinitcpio -P
+
+log "Regenerating GRUB config..."
+update-grub
+
+log "Done. Reboot recommended."