From: Doug Goldstein <cardoe@cardoe.com>
Date: Fri, 18 Dec 2020 02:27:14 +0000 (-0600)
Subject: zfs: fix LINUX_ROOT_DEVICE when grub-probe fails
X-Git-Tag: archive/raspbian/2.14_git20250718.0e36779-2+rpi1^2~7
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=ab217e2529fe49b6de9b60e2c47e7750ef65cdf4;p=grub2.git

zfs: fix LINUX_ROOT_DEVICE when grub-probe fails

When grub-probe fails, the current code is to just stuff an empty result
in which causes the user to not knowingly have a system that no longer
boots. grub-probe can fail because the ZFS pool that contains the root
filesystem might have features that grub does not yet support which is a
common configuration for people with a rpool and a bpool. This behavior
uses the zdb utility to dump the same value as the filesystem label
would print.

Signed-off-by: Doug Goldstein <cardoe@cardoe.com>

Gbp-Pq: Topic upstream
Gbp-Pq: Name zfs-fix-LINUX_ROOT_DEVICE-when-grub-probe-fails.patch
---

diff --git a/util/grub.d/10_linux.in b/util/grub.d/10_linux.in
index c47a8bb..268121d 100644
--- a/util/grub.d/10_linux.in
+++ b/util/grub.d/10_linux.in
@@ -89,7 +89,7 @@ case x"$GRUB_FS" in
 	    GRUB_CMDLINE_LINUX="rootflags=subvol=${rootsubvol} ${GRUB_CMDLINE_LINUX}"
 	fi;;
     xzfs)
-	rpool=`${grub_probe} --device ${GRUB_DEVICE} --target=fs_label 2>/dev/null || true`
+	rpool=`${grub_probe} --device ${GRUB_DEVICE} --target=fs_label 2>/dev/null || zdb -l ${GRUB_DEVICE} | awk -F \' '/ name/ { print $2 }'`
 	bootfs="`make_system_path_relative_to_its_root / | sed -e "s,@$,,"`"
 	LINUX_ROOT_DEVICE="ZFS=${rpool}${bootfs%/}"
 	;;
diff --git a/util/grub.d/20_linux_xen.in b/util/grub.d/20_linux_xen.in
index e73e96f..15597ad 100644
--- a/util/grub.d/20_linux_xen.in
+++ b/util/grub.d/20_linux_xen.in
@@ -81,7 +81,7 @@ case x"$GRUB_FS" in
 	    GRUB_CMDLINE_LINUX="rootflags=subvol=${rootsubvol} ${GRUB_CMDLINE_LINUX}"
 	fi;;
     xzfs)
-	rpool=`${grub_probe} --device ${GRUB_DEVICE} --target=fs_label 2>/dev/null || true`
+	rpool=`${grub_probe} --device ${GRUB_DEVICE} --target=fs_label 2>/dev/null || zdb -l ${GRUB_DEVICE} | awk -F \' '/ name/ { print $2 }'`
 	bootfs="`make_system_path_relative_to_its_root / | sed -e "s,@$,,"`"
 	LINUX_ROOT_DEVICE="ZFS=${rpool}${bootfs%/}"
 	;;