[pve-devel] applied: [RFC v2 storage] Revert "Fix #2020: use /sys to map nvmeXnY to nvmeX"

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

Am 28/11/2022 um 12:29 schrieb Fiona Ebner:
> 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@proxmox.com>
> ---
> 
> Changes from v1:
>     * Rebase on current master.
>     * Squash in style change putting post-if on the same line.
> 
> 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.

might want to try that then, we hopefully have a NVMe device with namespace
support, if not we can always get one.

> 
>  PVE/Diskmanage.pm                                      | 10 +---------
>  test/disk_tests/nvme_smart/nvme0n1/device              |  1 -
>  .../nvme_smart/{nvme0 => nvme0n1/device}/model         |  0
>  3 files changed, 1 insertion(+), 10 deletions(-)
>  delete mode 120000 test/disk_tests/nvme_smart/nvme0n1/device
>  rename test/disk_tests/nvme_smart/{nvme0 => nvme0n1/device}/model (100%)
> 
>

applied for now as stop-gap, thanks!