On Tue, 2018-02-27 at 15:09 +0800, chenxiang (M) wrote: > 在 2018/2/26 23:25, Bart Van Assche 写道: > > On Mon, 2018-02-26 at 17:37 +0800, chenxiang (M) wrote: > > > When i have a test on kernel 4.16-rc1, find a issue: running IO on SATA disk, then disable the disk through > > > sysfs interface(echo 0 > /sys/class/sas_phy/phy-1:0:0/enable), IO will hang and never enter SCSI EH. The issue > > > appears every time. > > > > > > I add some prints on code and find that those IOs will be timeout after 30s, and they all enter > > > function scsi_eh_scmd_add, but only some of them can enter function scsi_eh_inc_host_failed. So it will never > > > enter SCSI EH. I suspect it is related to the patch ("commit 3bd6f43f5cb371" scsi: core: Ensure that the > > > SCSI error handler gets woken up ). Please have a check. > > > > Hello chenxiang, > > > > Had you already noticed patch "[PATCH v2] Avoid that ATA error handling can > > trigger a kernel hang or oops"? If not, can you apply that patch to your > > kernel and verify whether it fixes this behavior? See also > > https://www.mail-archive.com/linux-scsi@xxxxxxxxxxxxxxx/msg71189.html or > > https://patchwork.kernel.org/patch/10236213/. > > After applied your patch, the issue i reported seems be solved. Thanks for having testing that patch! > But when i have long time test(disable/enable disk when running IO) on > the testcase, Null pointer occurs. > It seems not related to current issue but i am not sure. > I ran the testcase for long time before in kernel 4.15-rc5, and it was okay. > > Part of log is as follows, and i add attachment of log in the email : > > [ 485.716578] pc : blk_abort_request+0x14/0x68 (+Tejun) Hello chenxiang, Please check whether the following patch fixes the kernel crash you ran into: https://marc.info/?l=linux-block&m=151895951207014 Thanks, Bart.