[PATCH] nvme: honour O_NONBLOCK during resetting

[Keith Busch]

On Tue, Nov 16, 2021 at 01:40:04AM +0000, Chaitanya Kulkarni wrote:
> On 11/11/2021 2:59 AM, Hannes Reinecke wrote:
> > When opening a controller device node we should honour the O_NONBLOCK
> > flag to allow the device to be openend even if it's in state 'resetting'
> > or 'connecting'. This allows user-space applications to use a call to 'open'
> > to figure out if the controller is present, even if it's currently
> > undergoing a reset.
> > 
> > Signed-off-by: Hannes Reinecke <hare at suse.de>
> 
> Will resetting and connecting ever result is deleting the controller due
> to error cases present in that path ?
> 
> If yes then application will have handle for something that might
> go away in the future, should allow such a semantic ?

Resets can happen at any time, so they already have to handle it even if the
controller was live when they opened it. Perhaps the open should succeed for
any non-terminal state.