[-cc Pawel, Alexey, Tomasz, which all bounced] On Wed, Jul 10, 2024 at 09:29:25PM +0800, Jiwei Sun wrote: > On 7/10/24 04:59, Bjorn Helgaas wrote: > > [+cc Pawel, Alexey, Tomasz for mdadm history] > > On Wed, Jun 05, 2024 at 08:48:44PM +0800, Jiwei Sun wrote: > >> From: Jiwei Sun <sunjw10@xxxxxxxxxx> > >> > >> 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. > > > > I guess the root filesystem must be on a RAID device, and it's the > > failure to assemble that RAID device that prevents OS boot? The > > messages are just details about why the assembly failed? > > Yes, you are right, in our test environment, we installed the SLES15SP6 > on a VROC RAID 1 device which is set up by two NVME hard drivers. And > there is also a hardware RAID kit on the motherboard with other two NVME > hard drivers. OK, thanks for all the details. What would you think of updating the commit log like this? The vmd driver creates a "domain" symlink in sysfs for each VMD bridge. Previously this symlink was created after pci_bus_add_devices() added devices below the VMD bridge and emitted udev events to announce them to userspace. This led to a race between userspace consumers of the udev events and the kernel creation of the symlink. One such consumer is mdadm, which assembles block devices into a RAID array, and for devices below a VMD bridge, mdadm depends on the "domain" symlink. If mdadm loses the race, it may be unable to assemble a RAID array, which may cause a boot failure or other issues, with complaints like this: ... Create the VMD "domain" symlink before invoking pci_bus_add_devices() to avoid this race.
