From 5efac9cfed92a890dc1a073fe60b1c814c305267 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?St=C3=A9phane=20Graber?= <stgraber@ubuntu.com>
Date: Thu, 4 Nov 2021 14:05:27 -0400
Subject: [PATCH] lxd/storage/btrfs: Support 5.14.2
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Closes #9418

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
---
 lxd/storage/drivers/driver_btrfs.go       | 18 ++++++++++++++++++
 lxd/storage/drivers/driver_btrfs_utils.go |  8 +++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/lxd/storage/drivers/driver_btrfs.go b/lxd/storage/drivers/driver_btrfs.go
index e6a64bf8136..a47be766f8f 100644
--- a/lxd/storage/drivers/driver_btrfs.go
+++ b/lxd/storage/drivers/driver_btrfs.go
@@ -17,10 +17,12 @@ import (
 	"github.com/lxc/lxd/shared/api"
 	"github.com/lxc/lxd/shared/units"
 	"github.com/lxc/lxd/shared/validate"
+	"github.com/lxc/lxd/shared/version"
 )
 
 var btrfsVersion string
 var btrfsLoaded bool
+var btrfsPropertyForce bool
 
 type btrfs struct {
 	common
@@ -64,6 +66,22 @@ func (d *btrfs) load() error {
 		}
 	}
 
+	// Check if we need --force to set properties.
+	ver5142, err := version.Parse("5.14.2")
+	if err != nil {
+		return err
+	}
+
+	ourVer, err := version.Parse(btrfsVersion)
+	if err != nil {
+		return err
+	}
+
+	// If running 5.14.2 or older, we need --force.
+	if ourVer.Compare(ver5142) > 0 {
+		btrfsPropertyForce = true
+	}
+
 	btrfsLoaded = true
 	return nil
 }
diff --git a/lxd/storage/drivers/driver_btrfs_utils.go b/lxd/storage/drivers/driver_btrfs_utils.go
index e1a359e8490..0618e29e6f2 100644
--- a/lxd/storage/drivers/driver_btrfs_utils.go
+++ b/lxd/storage/drivers/driver_btrfs_utils.go
@@ -308,7 +308,13 @@ func (d *btrfs) setSubvolumeReadonlyProperty(path string, readonly bool) error {
 		return nil
 	}
 
-	_, err := shared.RunCommand("btrfs", "property", "set", "-ts", path, "ro", fmt.Sprintf("%t", readonly))
+	args := []string{"property", "set"}
+	if btrfsPropertyForce {
+		args = append(args, "-f")
+	}
+	args = append(args, "-ts", path, "ro", fmt.Sprintf("%t", readonly))
+
+	_, err := shared.RunCommand("btrfs", args...)
 	return err
 }