Re: [PATCH] scsi: core: run queues for all non-SDEV_DEL devices from scsi_run_host_queues

[Bart Van Assche <bvanassche@acm.org>]

On 5/13/26 10:35 AM, David Jeffery wrote:
> While a scsi host is in a recovery state, scsi_mq_requeue_cmd will not set
> the requeue list for a requeued command to be kicked in the future. The
> expectation is a call to scsi_run_host_queues will kick all scsi devices
> once the recovery state is cleared.
> 
> However, scsi_run_host_queues uses shost_for_each_device which uses
> scsi_device_get and so will ignore devices in a partially removed state like
> SDEV_CANCEL. But these devices may also have requeued requests, leaving
> their requests stuck from not being kicked and causing the removal process
> of the device to hang.
> 
> scsi_run_host_queues needs to run against more devices than the macro
> shost_for_each_device allows. Instead of using the too limiting
> scsi_device_get state checks, only ignore devices in SDEV_DEL state or
> when unable to acquire a reference. Attempt to run the queues for all other
> devices when scsi_run_host_queues is called.
 From scsi_host.h:

static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
{
	return shost->shost_state == SHOST_RECOVERY ||
		shost->shost_state == SHOST_CANCEL_RECOVERY ||
		shost->shost_state == SHOST_DEL_RECOVERY ||
		shost->tmf_in_progress;
}

This function returns false for the SDEV_CANCEL state. Hence, even with
commit 8b566edbdbfb ("scsi: core: Only kick the requeue list if
necessary") applied, the requeue list should still be kicked for SCSI
hosts in the SDEV_CANCEL state, isn't it?

Thanks,

Bart.