[pve-devel] [RFC manager] vzdump: exclude zfs control dirs by default

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

else in the face of snapdir=visible on a ZFS-backed mountpoint/rootfs, creating
stop mode backups will fail (because automounting on access of
.zfs/snapshot/XXX fails), and restoring a suspend mode backup onto a ZFS
storage will fail (because an attempt to `mkdir /path/to/target/.zfs/snapshot/XXX`
fails - or worse, if the "zfs_admin_snapshot" module parameter is enabled, will
create an XXX snapshot for the newly-restored dataset).

the two sub directories of .zfs were chosen to decrease the chance of false
positives, since backing up or restoring the .zfs dir itself is unproblematic.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---

Notes:
    see https://forum.proxmox.com/threads/restore-cannot-mkdir-permission-denied.121096
    
    alternatively, this could also be handled in pve-container by checking for each
    mountpoint and explicitly skipping .zfs only if that mountpoint is actually
    backed by a ZFS storage..
    
    if this patch is ACKed, the description of 'stdexcludes' in pve-guest-common should
    probably also be updated..

 PVE/VZDump.pm | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/PVE/VZDump.pm b/PVE/VZDump.pm
index a04837e7..9b9d37a8 100644
--- a/PVE/VZDump.pm
+++ b/PVE/VZDump.pm
@@ -542,6 +542,8 @@ sub new {
 	    '/tmp/?*',
 	    '/var/tmp/?*',
 	    '/var/run/?*.pid',
+	    '.zfs/snapshot',
+	    '.zfs/shares',
 	    ;
     }
 
-- 
2.30.2