Hello,
> During booting into the kernel, the following error message appears:
>
> (udev-worker)[2149]: nvme1n1: '/sbin/mdadm -I /dev/nvme1n1'(err) 'mdadm: Unable to get real path for '/sys/bus/pci/drivers/vmd/0000:c7:00.5/domain/device''
> (udev-worker)[2149]: nvme1n1: '/sbin/mdadm -I /dev/nvme1n1'(err) 'mdadm: /dev/nvme1n1 is not attached to Intel(R) RAID controller.'
> (udev-worker)[2149]: nvme1n1: '/sbin/mdadm -I /dev/nvme1n1'(err) 'mdadm: No OROM/EFI properties for /dev/nvme1n1'
> (udev-worker)[2149]: nvme1n1: '/sbin/mdadm -I /dev/nvme1n1'(err) 'mdadm: no RAID superblock on /dev/nvme1n1.'
> (udev-worker)[2149]: nvme1n1: Process '/sbin/mdadm -I /dev/nvme1n1' failed with exit code 1.
>
> This symptom prevents the OS from booting successfully.
>
> After a NVMe disk is probed/added by the nvme driver, the udevd executes
> some rule scripts by invoking mdadm command to detect if there is a
> mdraid associated with this NVMe disk. The mdadm determines if one
> NVMe devce is connected to a particular VMD domain by checking the
> domain symlink. Here is the root cause:
>
> Thread A Thread B Thread mdadm
> vmd_enable_domain
> pci_bus_add_devices
> __driver_probe_device
> ...
> work_on_cpu
> schedule_work_on
> : wakeup Thread B
> nvme_probe
> : wakeup scan_work
> to scan nvme disk
> and add nvme disk
> then wakeup udevd
> : udevd executes
> mdadm command
> flush_work main
> : wait for nvme_probe done ...
> __driver_probe_device find_driver_devices
> : probe next nvme device : 1) Detect the domain
> ... symlink; 2) Find the
> ... domain symlink from
> ... vmd sysfs; 3) The
> ... domain symlink is not
> ... created yet, failed
> sysfs_create_link
> : create domain symlink
>
> sysfs_create_link() is invoked at the end of vmd_enable_domain().
> However, this implementation introduces a timing issue, where mdadm
> might fail to retrieve the vmd symlink path because the symlink has not
> been created yet.
>
> Fix the issue by creating VMD domain symlinks before invoking
> pci_bus_add_devices().
Applied to vmd, thank you!
[1/1] PCI: vmd: Create domain symlink before pci_bus_add_devices()
https://git.kernel.org/pci/pci/c/7a13782e6150
Krzysztof
