[pve-devel] [PATCH storage] rbd: get_rbd_dev_path: return /dev/rbd path only if cluster matches

[Aaron Lauterer]

ping?

On 5/23/22 12:54, Aaron Lauterer wrote:
> The changes in cfe46e2d4a97a83f1bbe6ad656e6416399309ba2 git not catch
> all situations.
> In the case of a guest having 2 disk images with the same name on a pool
> with the same name but in two different ceph clusters we still had
> issues when starting it. The first disk got mapped as expected. The
> second disk did not get mapped because we returned the old $path to
> "/dev/rbd/<pool>/<image>" because it already existed from the first
> disk.
> 
> In the case that only the "old" /dev/rbd path exists and we do not have
> the /dev/rbd-pve/<cluster>/... path available, we now check if the
> cluster fsid used by that rbd device matches the one we expect. If it
> does, then we are in the situation that the image has been mapped before
> the new rbd-pve udev rule was introduced. If it does not, then we have
> the situation of an ambiguous mapping in /dev/rbd and return the
> $pve_path.
> 
> Signed-off-by: Aaron Lauterer <a.lauterer at proxmox.com>
> ---
>   PVE/Storage/RBDPlugin.pm | 11 +++++++++--
>   1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/PVE/Storage/RBDPlugin.pm b/PVE/Storage/RBDPlugin.pm
> index 3511914..eeeaf3f 100644
> --- a/PVE/Storage/RBDPlugin.pm
> +++ b/PVE/Storage/RBDPlugin.pm
> @@ -3,6 +3,7 @@ package PVE::Storage::RBDPlugin;
>   use strict;
>   use warnings;
>   
> +use Cwd qw(abs_path);
>   use IO::File;
>   use JSON;
>   use Net::IP;
> @@ -13,7 +14,7 @@ use PVE::JSONSchema qw(get_standard_option);
>   use PVE::ProcFSTools;
>   use PVE::RADOS;
>   use PVE::Storage::Plugin;
> -use PVE::Tools qw(run_command trim);
> +use PVE::Tools qw(run_command trim file_read_firstline);
>   
>   use base qw(PVE::Storage::Plugin);
>   
> @@ -66,7 +67,13 @@ my sub get_rbd_dev_path {
>       my $pve_path = "/dev/rbd-pve/${cluster_id}/${rbd_path}";
>       my $path = "/dev/rbd/${rbd_path}";
>   
> -    return $path if !-e $pve_path && -e $path; # mapped before rbd-pve udev rule existed
> +    if (!-e $pve_path && -e $path) {
> +	# possibly mapped before rbd-pve rule existed
> +	my $real_dev = abs_path($path);
> +	my ($rbd_id) = ($real_dev =~ m|/dev/rbd([0-9]+)$|);
> +	my $dev_cluster_id = file_read_firstline("/sys/devices/rbd/${rbd_id}/cluster_fsid");
> +	return $path if $cluster_id eq $dev_cluster_id;
> +    }
>       return $pve_path;
>   }
>