[SCSI] libata, libsas: introduce sched_eh and end_eh port ops

When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship.  libsas creates a 1:N relationship
so it needs to manage host_eh_scheduled cumulatively at the host level.
The sched_eh and end_eh port port ops allow libsas to track when domain
devices enter/leave the "eh-pending" state under ha->lock (previously
named ha->state_lock, but it is no longer just a lock for ha->state
changes).

Since host_eh_scheduled indicates eh without backing commands pinning
the device it can be deallocated at any time.  Move the taking of the
domain_device reference under the port_lock to guarantee that the
ata_port stays around for the duration of eh.

Reviewed-by: Jacek Danecki <[email protected]>
Acked-by: Jeff Garzik <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
Signed-off-by: James Bottomley <[email protected]>
This commit is contained in:
Dan Williams 2012-06-21 23:25:27 -07:00 • committed by James Bottomley
commit e4a9c3732c
10 changed files with 134 additions and 37 deletions

View file

@ -80,6 +80,8 @@ const struct ata_port_operations ata_base_port_ops = {
.prereset = ata_std_prereset,
.postreset = ata_std_postreset,
.error_handler = ata_std_error_handler,
.sched_eh = ata_std_sched_eh,
.end_eh = ata_std_end_eh,
};
const struct ata_port_operations sata_port_ops = {
@ -6642,6 +6644,8 @@ struct ata_port_operations ata_dummy_port_ops = {
.qc_prep = ata_noop_qc_prep,
.qc_issue = ata_dummy_qc_issue,
.error_handler = ata_dummy_error_handler,
.sched_eh = ata_std_sched_eh,
.end_eh = ata_std_end_eh,
};
const struct ata_port_info ata_dummy_port_info = {

View file

@ -793,12 +793,12 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
ata_for_each_link(link, ap, HOST_FIRST)
memset(&link->eh_info, 0, sizeof(link->eh_info));
/* Clear host_eh_scheduled while holding ap->lock such
* that if exception occurs after this point but
* before EH completion, SCSI midlayer will
/* end eh (clear host_eh_scheduled) while holding
* ap->lock such that if exception occurs after this
* point but before EH completion, SCSI midlayer will
* re-initiate EH.
*/
host->host_eh_scheduled = 0;
ap->ops->end_eh(ap);
spin_unlock_irqrestore(ap->lock, flags);
ata_eh_release(ap);
@ -985,6 +985,48 @@ void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
spin_unlock_irqrestore(q->queue_lock, flags);
}
/**
* ata_std_sched_eh - non-libsas ata_ports issue eh with this common routine
* @ap: ATA port to schedule EH for
*
* LOCKING: inherited from ata_port_schedule_eh
* spin_lock_irqsave(host lock)
*/
void ata_std_sched_eh(struct ata_port *ap)
{
WARN_ON(!ap->ops->error_handler);
if (ap->pflags & ATA_PFLAG_INITIALIZING)
return;
ata_eh_set_pending(ap, 1);
scsi_schedule_eh(ap->scsi_host);
DPRINTK("port EH scheduled\n");
}
EXPORT_SYMBOL_GPL(ata_std_sched_eh);
/**
* ata_std_end_eh - non-libsas ata_ports complete eh with this common routine
* @ap: ATA port to end EH for
*
* In the libata object model there is a 1:1 mapping of ata_port to
* shost, so host fields can be directly manipulated under ap->lock, in
* the libsas case we need to hold a lock at the ha->level to coordinate
* these events.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
void ata_std_end_eh(struct ata_port *ap)
{
struct Scsi_Host *host = ap->scsi_host;
host->host_eh_scheduled = 0;
}
EXPORT_SYMBOL(ata_std_end_eh);
/**
* ata_port_schedule_eh - schedule error handling without a qc
* @ap: ATA port to schedule EH for
@ -997,15 +1039,8 @@ void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
*/
void ata_port_schedule_eh(struct ata_port *ap)
{
WARN_ON(!ap->ops->error_handler);
if (ap->pflags & ATA_PFLAG_INITIALIZING)
return;
ata_eh_set_pending(ap, 1);
scsi_schedule_eh(ap->scsi_host);
DPRINTK("port EH scheduled\n");
/* see: ata_std_sched_eh, unless you know better */
ap->ops->sched_eh(ap);
}
static int ata_do_link_abort(struct ata_port *ap, struct ata_link *link)