On 8/26/25 2:38 PM, Ming Lei wrote: > On Tue, Aug 26, 2025 at 02:00:56PM +0530, Venkat Rao Bagalkote wrote: >> Greetings!!! >> >> >> IBM CI has reported a kernel OOPs, while running blktest suite(nvme/058 >> test). >> >> >> Kernel Repo: >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >> >> >> Traces: >> >> >> [37496.800225] BUG: Kernel NULL pointer dereference at 0x00000000 >> [37496.800230] Faulting instruction address: 0xc0000000008a34b0 >> [37496.800235] Oops: Kernel access of bad area, sig: 11 [#1] > > ... > >> [37496.800365] GPR28: 0000000000000001 0000000000000001 c0000000b005c400 >> 0000000000000000 >> [37496.800424] NIP [c0000000008a34b0] __rq_qos_done_bio+0x3c/0x88 > > It looks regression from 370ac285f23a ("block: avoid cpu_hotplug_lock depedency on freeze_lock"), > For nvme mpath, same bio crosses two drivers, so QUEUE_FLAG_QOS_ENABLED & q->rq_qos check can't > be skipped. > Thanks Ming for looking at it. And yes you were correct, we can't skip QUEUE_FLAG_QOS_ENABLED & q->rq_qos for NVMe, However this issue only manifests with NVMe multipath enabled, as that would create the stacked NVMe devices. So shall I send the fix or are you going to send the patch with fix? Thanks, --Nilay
