[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 <jacek.danecki@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index cece3a4d11ea..3fe1202c61ce 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -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 = {