[pve-devel] [RFC storage] Revert "Fix #2020: use /sys to map nvmeXnY to nvmeX"

[Stefan Hrdlicka]

Bump ...

Hi,

had a customer ticket this week with this issue. Couldn't test because 
the patch doesn't apply :).


On 9/2/22 13:35, Fiona Ebner wrote:
> This reverts commit c3442aa5546b029a524928d10c7ecabe0024c137.
> 
> Nowadays, relying on 'readlink /sys/block/nvmeXnY/device' won't always
> lead to the correct device, as reported in the community forum[0],
> where it results in '../../nvme-subsys0' and there's no matching entry
> under '/dev/'.
> 
> Since Linux kernel 5.4, in particular commit 733e4b69d508 ("nvme:
> Assign subsys instance from first ctrl"), the problematic situation
> from bug #2020 shouldn't happen anymore.
> 
> Stated more clearly by the commit's author here[1]:
>> Indeed, that commit will make the naming a bit more sane and will
>> definitely prevent mistaken identity. It is still possible to
>> observe controllers with instances that don't match their
>> namespaces, but it is impossible to get a namespace instance that
>> matches a non-owning controller.
> 
> The only other user of get_sysdir_info() doesn't use the 'device'
> entry, so reverting that part is fine too.
> 
> [0] https://forum.proxmox.com/threads/113962/
> [1] https://github.com/linux-nvme/nvme-cli/issues/510#issuecomment-552508647
> 
> Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
> ---
> 
> Alternatively, we might want to switch to passing the namespaced
> device name directly to smartctl. According to 'man smartcl', it's
> supported and it works for me and the user in the forum. However,
> AFAICT, the stated support was already present in smartmontools 6.5,
> but c9bd3d2 ("fix #1123: modify NVME device path for SMART support")
> references that version and mentions that it's necessary to drop the
> namespace, so really not sure.
> 
>   PVE/Diskmanage.pm                                    | 12 ++----------
>   test/disk_tests/nvme_smart/nvme0n1/device            |  1 -
>   .../nvme_smart/{nvme0 => nvme0n1/device}/model       |  0
>   3 files changed, 2 insertions(+), 11 deletions(-)
>   delete mode 120000 test/disk_tests/nvme_smart/nvme0n1/device
>   rename test/disk_tests/nvme_smart/{nvme0 => nvme0n1/device}/model (100%)
> 
> diff --git a/PVE/Diskmanage.pm b/PVE/Diskmanage.pm
> index 8ed7a8b..7eb193f 100644
> --- a/PVE/Diskmanage.pm
> +++ b/PVE/Diskmanage.pm
> @@ -95,11 +95,8 @@ sub get_smart_data {
>   
>       my $returncode = 0;
>   
> -    if ($disk =~ m!^/dev/(nvme\d+n\d+)$!) {
> -	my $info = get_sysdir_info("/sys/block/$1");
> -	$disk = "/dev/".($info->{device}
> -	    or die "failed to get nvme controller device for $disk\n");
> -    }
> +    $disk =~ s/n\d+$//
> +        if $disk =~ m!^/dev/nvme\d+n\d+$!;
>   
>       my $cmd = [$SMARTCTL, '-H'];
>       push @$cmd, '-A', '-f', 'brief' if !$healthonly;
> @@ -406,11 +403,6 @@ sub get_sysdir_info {
>       $data->{vendor} = file_read_firstline("$sysdir/device/vendor") || 'unknown';
>       $data->{model} = file_read_firstline("$sysdir/device/model") || 'unknown';
>   
> -    if (defined(my $device = readlink("$sysdir/device"))) {
> -	# strip directory and untaint:
> -	($data->{device}) = $device =~ m!([^/]+)$!;
> -    }
> -
>       return $data;
>   }
>   
> diff --git a/test/disk_tests/nvme_smart/nvme0n1/device b/test/disk_tests/nvme_smart/nvme0n1/device
> deleted file mode 120000
> index e890f3e..0000000
> --- a/test/disk_tests/nvme_smart/nvme0n1/device
> +++ /dev/null
> @@ -1 +0,0 @@
> -../nvme0
> \ No newline at end of file
> diff --git a/test/disk_tests/nvme_smart/nvme0/model b/test/disk_tests/nvme_smart/nvme0n1/device/model
> similarity index 100%
> rename from test/disk_tests/nvme_smart/nvme0/model
> rename to test/disk_tests/nvme_smart/nvme0n1/device/model