[pve-devel] [PATCH storage 2/2] btrfs: forcefully set image to readwrite

[Maximiliano Sandoval]

When a subvolume is transferred via btrfs send/receive the resulting
image contains the received_uuid property set. This property is required
to do incremental snapshots.

A downside though is that once the received_uuid property is set, it is
not possible to make the image readwrite again without the force (-f)
flag, and in such case the received_uuid property is lost. Since we know
the images are only set to rw for the duration of the move, it is safe
to set the flag forcefully and then in a future commit add the
received_uuid proprty by force.

Signed-off-by: Maximiliano Sandoval <m.sandoval at proxmox.com>
---
 src/PVE/Storage/BTRFSPlugin.pm | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/PVE/Storage/BTRFSPlugin.pm b/src/PVE/Storage/BTRFSPlugin.pm
index dc0420d..9a9dd51 100644
--- a/src/PVE/Storage/BTRFSPlugin.pm
+++ b/src/PVE/Storage/BTRFSPlugin.pm
@@ -870,7 +870,7 @@ sub volume_import {
 	# Rotate the disk into place, first the current state:
 	# Note that read-only subvolumes cannot be moved into different directories, but for the
 	# "current" state we also want a writable copy, so start with that:
-	$class->btrfs_cmd(['property', 'set', "$tmppath/$diskname\@$snapshot", 'ro', 'false']);
+	$class->btrfs_cmd(['property', 'set', '-f', "$tmppath/$diskname\@$snapshot", 'ro', 'false']);
 	PVE::Tools::renameat2(
 	    -1,
 	    "$tmppath/$diskname\@$snapshot",
@@ -892,7 +892,7 @@ sub volume_import {
 
 	# Now go through the remaining snapshots (if any)
 	foreach my $snap (@snapshots) {
-	    $class->btrfs_cmd(['property', 'set', "$tmppath/$diskname\@$snap", 'ro', 'false']);
+	    $class->btrfs_cmd(['property', 'set', '-f', "$tmppath/$diskname\@$snap", 'ro', 'false']);
 	    PVE::Tools::renameat2(
 		-1,
 		"$tmppath/$diskname\@$snap",
-- 
2.39.2