> -----Original Message----- > From: James Bottomley [mailto:james.bottom...@hansenpartnership.com] > Sent: Tuesday, October 09, 2012 7:38 AM > To: KY Srinivasan > Cc: gre...@linuxfoundation.org; linux-kernel@vger.kernel.org; > de...@linuxdriverproject.org; oher...@suse.com; h...@infradead.org; linux- > s...@vger.kernel.org; sta...@vger.kernel.org > Subject: Re: [PATCH 1/1] Drivers: scsi: storvsc: Account for in-transit > packets in > the RESET path > > On Mon, 2012-10-08 at 15:51 +0000, KY Srinivasan wrote: > > > > > -----Original Message----- > > > From: K. Y. Srinivasan [mailto:k...@microsoft.com] > > > Sent: Tuesday, October 02, 2012 2:04 PM > > > To: gre...@linuxfoundation.org; linux-kernel@vger.kernel.org; > > > de...@linuxdriverproject.org; oher...@suse.com; > jbottom...@parallels.com; > > > h...@infradead.org; linux-s...@vger.kernel.org > > > Cc: KY Srinivasan; sta...@vger.kernel.org > > > Subject: [PATCH 1/1] Drivers: scsi: storvsc: Account for in-transit > > > packets in > the > > > RESET path > > > > > > Properly account for I/O in transit before returning from the RESET call. > > > In the absense of this patch, we could have a situation where the host may > > > respond to a command that was issued prior to the issuance of the RESET > > > command at some arbitrary time after responding to the RESET command. > > > Currently, the host does not do anything with the RESET command. > > > > > > Signed-off-by: K. Y. Srinivasan <k...@microsoft.com> > > > Cc: sta...@vger.kernel.org > > > --- > > > drivers/scsi/storvsc_drv.c | 5 +++++ > > > 1 files changed, 5 insertions(+), 0 deletions(-) > > > > > > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c > > > index 528d52b..0144078 100644 > > > --- a/drivers/scsi/storvsc_drv.c > > > +++ b/drivers/scsi/storvsc_drv.c > > > @@ -1221,7 +1221,12 @@ static int storvsc_host_reset_handler(struct > scsi_cmnd > > > *scmnd) > > > /* > > > * At this point, all outstanding requests in the adapter > > > * should have been flushed out and return to us > > > + * There is a potential race here where the host may be in > > > + * the process of responding when we return from here. > > > + * Just wait for all in-transit packets to be accounted for > > > + * before we return from here. > > > */ > > > + storvsc_wait_to_drain(stor_device); > > > > > > return SUCCESS; > > > } > > > -- > > > 1.7.4.1 > > > > James, > > > > This patch is critical for running Linux based workloads on our Cloud > infrastructure - Azure. > > Please let me know if there are any issues. > > So just for next time: it's a bit hard to work out this is a critical > issue from the change log. If I had to guess, I'd say the response to a > command killed by reset causes some type of use after free and a > potential oops (all of which would have been very nice in the change > log)?
You guessed right! My apologies, I will add such details in the change log in the future. Regards, K. Y > > James > > > >
