Re: [RFC PATCH 1/7] 13-dm-disk.rules: import ID_FS_TYPE

[Peter Rajnoha <prajnoha@redhat.com>]

On 3/1/24 23:40, Martin Wilck wrote:
> ID_FS_TYPE is the most important udev property for most follow-up
> rules. It must be imported from the udev db if blkid can't be run.
> 
> Signed-off-by: Martin Wilck <mwilck@suse.com>
> ---
>  udev/13-dm-disk.rules.in | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/udev/13-dm-disk.rules.in b/udev/13-dm-disk.rules.in
> index dca00bc..eaad972 100644
> --- a/udev/13-dm-disk.rules.in
> +++ b/udev/13-dm-disk.rules.in
> @@ -26,6 +26,7 @@ ENV{DM_NOSCAN}=="1", GOTO="dm_watch"
>  GOTO="dm_link"
>  
>  LABEL="dm_import"
> +IMPORT{db}="ID_FS_TYPE"
>  IMPORT{db}="ID_FS_USAGE"
>  IMPORT{db}="ID_FS_UUID_ENC"
>  IMPORT{db}="ID_FS_LABEL_ENC"

I think this one was left out deliberately. The original intention was
to import only the minimal set of "blkid" variables needed to properly
keep the symlinks based on these values in place (patch 94f77a4). And
the "ID_FS_TYPE" is not actually needed for this.

Though, importing even the "ID_FS_TYPE" together with other blkid
variables should not be an issue because this "import from previous
state" happens only if we have DM_SUSPENDED or DM_NOSCAN set for current
event, in which case any other rules should be also disabled with
DM_UDEV_DISABLE_OTHER_RULES_FLAG="1".

So even if some other rule fires based on ID_FS_TYPE value, the
DM_UDEV_DISABLE_OTHER_RULES_FLAG should stop it anyway.

Then, the question is whether we really need to 'IMPORT{db}="ID_FS_TYPE'?

-- 
Peter