Re: [PATCH v2 1/2] ata: libata-scsi: terminate deferred commands on time out

[Niklas Cassel <cassel@kernel.org>]

On Fri, Jul 10, 2026 at 04:25:38PM +0900, Damien Le Moal wrote:
> > [Severity: High]
> > Does this function need to set ATA_PFLAG_EH_PENDING?
> > 
> > Because this flag is not set, ata_port_eh_scheduled() will evaluate to
> > false. This allows the block layer to immediately retry the requeued
> > commands, which __ata_scsi_queuecmd() will accept and re-defer, keeping
> > the host busy.
> 
> No it will not because this is called with SCSI EH already waiting to run, so
> newly incoming commands are not passed down by the scsi layer.

Could you please point to specific functions + lines in the code?

AFAICT, I don't see how SCSI EH is waiting to run when
scsi_eh_scmd_add() has not yet been called.

Note that all the places that currently call ata_scsi_requeue_deferred_qc()
are called when ATA_PFLAG_EH_PENDING | ATA_PFLAG_EH_IN_PROGRESS
(ata_port_eh_scheduled() evaluates to true).

We could add an WARN_ON(!ata_port_eh_scheduled) in ata_scsi_requeue_deferred_qc()
and we would never see the warning.

With the new function ata_scsi_port_eh_timed_out(), AFAICT, it can call
ata_scsi_requeue_deferred_qc() before ata_port_eh_scheduled() evaluates to true.

See e.g. the commit message for:
e20e81a24a4d ("ata: libata-core: do not issue non-internal commands once EH is pending")
of why I think __ata_scsi_queuecmd() will accept new commands.


Kind regards,
Niklas