Re: [PATCH v3 5/6] block: Make SCSI device suspend and resume work reliably

2017-09-25 Thread Bart Van Assche
On Tue, 2017-09-26 at 06:51 +0800, Ming Lei wrote: > On Mon, Sep 25, 2017 at 04:20:20PM +, Bart Van Assche wrote: > > So that means that you have not noticed that it is safe to leave out that > > smp_rmp() call because blk-mq queue freezing and unfreezing waits for a > > grace > > period and

Re: [PATCH v3 5/6] block: Make SCSI device suspend and resume work reliably

2017-09-25 Thread Ming Lei
On Mon, Sep 25, 2017 at 04:20:20PM +, Bart Van Assche wrote: > On Mon, 2017-09-25 at 10:26 +0800, Ming Lei wrote: > > On Fri, Sep 22, 2017 at 03:14:04PM -0700, Bart Van Assche wrote: > > > +int blk_queue_enter(struct request_queue *q, bool nowait, bool preempt) > > > { > > > while (true) {

Re: [PATCH v3 5/6] block: Make SCSI device suspend and resume work reliably

2017-09-25 Thread Bart Van Assche
On Mon, 2017-09-25 at 10:26 +0800, Ming Lei wrote: > On Fri, Sep 22, 2017 at 03:14:04PM -0700, Bart Van Assche wrote: > > +int blk_queue_enter(struct request_queue *q, bool nowait, bool preempt) > > { > > while (true) { > > int ret; > > > > - if

Re: [PATCH v3 5/6] block: Make SCSI device suspend and resume work reliably

2017-09-24 Thread Ming Lei
On Fri, Sep 22, 2017 at 03:14:04PM -0700, Bart Van Assche wrote: > It is essential during suspend and resume that neither the filesystem > state nor the filesystem metadata in RAM changes. This is why while > the hibernation image is being written or restored that SCSI devices > are quiesced. The

[PATCH v3 5/6] block: Make SCSI device suspend and resume work reliably

2017-09-22 Thread Bart Van Assche
It is essential during suspend and resume that neither the filesystem state nor the filesystem metadata in RAM changes. This is why while the hibernation image is being written or restored that SCSI devices are quiesced. The SCSI core quiesces devices through scsi_device_quiesce() and