[pve-devel] [PATCH storage] fix 3214: DirPlugin: die early if mountpoint not mounted

[Wolfgang Bumiller]

Here our `mkdir` meaning is `create the path to the storage`.

I'd propose the following:

Apply neither #3214 patch. Keep the `mkdir` code as it is. Deprecate the
`mkdir` option and split it up into 2 new options:

`create_path` and `populate_directory`

It should be harder to confuse those two in the future (plus they can
both be set explicitly simultaneously).

On Tue, Dec 22, 2020 at 01:18:52PM +0100, Aaron Lauterer wrote:
> If the `is_mountpoint` option is enabled, it is sensible to first check
> for the mountpoint before proceeding any further in the storage
> activation.
> 
> The old behaviour would create the path to the mountpoint if the `mdkir`
> option wasn't set to false. This resulted in mountpoints further up
> the path to not mount anymore, e.g. nested ZFS datasets.
> 
> Signed-off-by: Aaron Lauterer <a.lauterer at proxmox.com>
> ---
> 
> There is another patch[0] already for this bug report but it deals with
> a related, but different problem of not creating the internal storage
> directory structure if `mkdir 0` was set.
> 
> [0] https://lists.proxmox.com/pipermail/pve-devel/2020-December/046572.html
> 
>  PVE/Storage/DirPlugin.pm | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/PVE/Storage/DirPlugin.pm b/PVE/Storage/DirPlugin.pm
> index 2267f11..81aaf2b 100644
> --- a/PVE/Storage/DirPlugin.pm
> +++ b/PVE/Storage/DirPlugin.pm
> @@ -132,17 +132,17 @@ sub status {
>  sub activate_storage {
>      my ($class, $storeid, $scfg, $cache) = @_;
>  
> -    my $path = $scfg->{path};
> -    if (!defined($scfg->{mkdir}) || $scfg->{mkdir}) {
> -	mkpath $path;
> -    }

Depending on whether we want to also "fix" the defaults (`mkdir` not
present meaning it is not *used*, rather than it is `on`), the above
should either happen `if !defined($scfg->{create_path})` (not explicitly
using `create_path`), or changed to `if ($scfg->{mkdir})` (which should
generate a warning).

> -
>      my $mp = parse_is_mountpoint($scfg);
>      if (defined($mp) && !path_is_mounted($mp, $cache->{mountdata})) {
>  	die "unable to activate storage '$storeid' - " .
>  	    "directory is expected to be a mount point but is not mounted: '$mp'\n";
>      }
>  

the `is_mountpoint` check would stay here after `mkdir` handling for
legacy behavior.
and below here is where we'd add the hunk below with
`s/mkdir/populate_directory/`;

The other patch would do use `populate_directory` if it is explicitly
set, otherwise fall through to the old `mkdir` based code with a
warning that `populate_directory` should be explicitly set in the
config.


> +    my $path = $scfg->{path};
> +    if (!defined($scfg->{mkdir}) || $scfg->{mkdir}) {
> +	mkpath $path;
> +    }
> +
>      $class->SUPER::activate_storage($storeid, $scfg, $cache);
>  }
>  
> -- 
> 2.20.1