Re: [PATCH 1/1] scsi: Add added_to_sysfs sdev flag to fix device scanning oops

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Mon, 2008-08-18 at 09:06 -0500, Brian King wrote:
> James Bottomley wrote:
> > What this seems to be exposing is a bug in the state model around the
> > blocked state.
> > 
> > The transition:
> > 
> > CREATED -> BLOCK -> RUNNING
> > 
> > shouldn't be legal.  My initial reaction is just to forbid the CREATED
> > -> BLOCK transition, but it looks like the fc transport code never
> > checks return values from scsi_target_block() (sigh!)
> > 
> > So an alternate fix should be to correct the state model rather than try
> > and work around the deficiencies with additional flags.
> > 
> > It looks like, to allow the CREATED -> BLOCK -> CREATED transition we
> > need an extra state (CREATED_BLOCK) and we forbid the CREATED -> BLOCK
> > in favour of it.
> > 
> > The model also now allows an online transition to do CREATED_BLOCK ->
> > BLOCK
> > 
> > This is a rough code of that, does it work for you?
> 
> I loaded up your patch and this fixes my issue as well. Do we need to also
> add a check for SDEV_CREATED_BLOCK in scsi_dispatch_cmd?

Yes ... everywhere we previously checked for SDEV_BLOCK ... really, that
check now needs to be made into an inline function.  I'll reroll the
patch properly with that included.

James