On 08/10/2017 10:26 AM, Bart Van Assche wrote: > On Thu, 2017-08-10 at 20:32 +1000, Michael Ellerman wrote: >> "Martin K. Petersen" <martin.petersen@xxxxxxxxxx> writes: >>>> One of the two scsi-mq functions that requeue a request unprepares a >>>> request before requeueing (scsi_io_completion()) but the other >>>> function not (__scsi_queue_insert()). Make sure that a request is >>>> unprepared before requeuing it. >>> >>> Applied to 4.13/scsi-fixes. Thanks much! >> >> This seems to be preventing my Power8 box, which uses IPR, from booting. >> >> Bisect said so: >> >> # first bad commit: [270065e92c317845d69095ec8e3d18616b5b39d5] scsi: scsi-mq: Always unprepare before requeuing a request >> >> And if I revert that on top of next-20170809 my system boots again. >> >> The symptom is that it just gets "stuck" during boot and never gets to >> mounting root, full log below, the end is: >> >> . >> ready >> ready >> sd 0:2:4:0: [sde] 554287104 512-byte logical blocks: (284 GB/264 GiB) >> sd 0:2:4:0: [sde] 4096-byte physical blocks >> sd 0:2:5:0: [sdf] 272646144 512-byte logical blocks: (140 GB/130 GiB) >> sd 0:2:5:0: [sdf] 4096-byte physical blocks >> sd 0:2:4:0: [sde] Write Protect is off >> sd 0:2:4:0: [sde] Mode Sense: 0b 00 00 08 >> sd 0:2:5:0: [sdf] Write Protect is off >> sd 0:2:5:0: [sdf] Mode Sense: 0b 00 00 08 >> >> >> And it just sits there for at least hours. >> >> I compared a good and bad boot log and there appears to be essentially >> no difference. Certainly nothing that looks suspicous. > > Hello Michael, > > Thanks for having reported this early. Is there any chance that you can > reproduce this state, press SysRq-w on the console and collect the task > overview that is reported on the console (see also Documentation/admin-guide/ > sysrq.rst)? If this is not possible or if that task overview does not report > any blocked tasks, can you add scsi_mod.scsi_logging_level=-1 to the kernel > command line (either through /etc/default/grub or in /boot/grub2/grub.cfg > when using GRUB), reboot the system, capture the console output and report > that output as a reply to this e-mail? I'm building a kernel to try to reproduce this on a machine with ipr. -Brian -- Brian King Power Linux I/O IBM Linux Technology Center
