From 89c18fac339894523134be37d986e5d63e307dff Mon Sep 17 00:00:00 2001
From: Alexander Burmashev <alexander.burmashev@oracle.com>
Date: Mon, 7 Nov 2022 02:22:12 -0800
Subject: [PATCH] Do not add /boot twice for btrfs subvolumes

Upstream does not care about btrfs subvolumes, but we do.
When grubby calculates the prefix we additionaly check:
1) if /boot fs is btrfs
2) and if /boot is a subvolume
we do not append additional /boot to kernel path.

256 is the inode nr for subvolume per BTRFS specification and docs
Without this fix grubby reports kernel path to be
/boot/boot

Orabug: 34380742
Signed-off-by: Alexander Burmashev <alexander.burmashev@oracle.com>
--- grubby-bls.old	2022-11-07 02:23:47.000000000 -0800
+++ grubby-bls	2022-11-07 04:50:09.138586241 -0800
@@ -198,10 +198,14 @@
 
 get_prefix() {
     if [[ $bootloader = grub2 ]] && mountpoint -q /boot; then
-	echo "/boot"
+	prefix_kern="/boot"
     else
-	echo ""
+	prefix_kern=""
     fi
+    if [[ $(stat -f --format=%T /boot) = "btrfs" ]] && [[ $(stat --format=%i /boot) = "256" ]]; then
+	prefix_kern=""
+    fi
+    echo "$prefix_kern"
 }
 
 expand_var() {