On Fri, Dec 01, 2017 at 04:08:49PM +0000, Bart Van Assche wrote: > On Fri, 2017-12-01 at 13:36 -0200, Mauricio Faria de Oliveira wrote: > > On 11/29/2017 12:57 AM, chenxiang (M) wrote: > > > I applied this v2 patchset to kernel 4.15-rc1, running fio on a SATA > > > disk, then disable the disk with sysfs interface > > > (echo 0 > /sys/class/sas_phy/phy-1:0:1/enable), and find system is hung. > > > But with v1 patch, it doesn't > > > has this issue. Please have a check. > > > > Indeed, with this particular test-case (thanks, chenxiang) the problem > > can be recreated with PATCH v2 but _not_ with v1. > > > > For reference, I'm including the tests with v2 in this e-mail. > > The same tests have too been performed with v1, without blocked tasks. > > > > Interestingly, physical disk pulls did not hit the problem either > > on v1 or v2 (but it does not matter anymore) -- so v1 is the one. > > The test chenxiang ran does not prove that there is anything wrong with v2. > Maybe chenxiang hit the issue described in https://lkml.org/lkml/2017/9/5/381? No, if the issue is in SCSI EH, blk_drain_queue() shouldn't have moved on too. Anyway, V1/V3 is the correct thing to do. Thanks, Ming
