On Fri, Dec 01, 2017 at 01:36:13PM -0200, Mauricio Faria de Oliveira wrote:

Hi Ming Lei,

On 11/29/2017 12:57 AM, chenxiang (M) wrote:

quoted

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.

V1 has been resent out in the following link with your tested-by:

	https://marc.info/?l=linux-block&m=151200356024020&w=2

Jens, since it fixes regression from two reports, could you take a look?

-- 
Ming