[SCSI] libsas: enforce eh strategy handlers only in eh context

The strategy handlers may be called in places that are problematic for
libsas (i.e. sata resets outside of domain revalidation filtering /
libata link recovery), or problematic for userspace (non-blocking ioctl
to sleeping reset functions).  However, these routines are also called
for eh escalations and recovery of scsi_eh_prep_cmnd(), so permit them
as long as we are running in the host's error handler, otherwise arrange
for them to be triggered in eh_context.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 814d8cb..df9cefd 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -176,10 +176,17 @@ struct sata_device {
 	u8     fis[ATA_RESP_FIS_SIZE];
 };
 
+struct ssp_device {
+	struct list_head eh_list_node; /* pending a user requested eh action */
+	struct scsi_lun reset_lun;
+};
+
 enum {
 	SAS_DEV_GONE,
 	SAS_DEV_DESTROY,
 	SAS_DEV_EH_PENDING,
+	SAS_DEV_LU_RESET,
+	SAS_DEV_RESET,
 };
 
 struct domain_device {
@@ -213,6 +220,7 @@ struct domain_device {
         union {
                 struct expander_device ex_dev;
                 struct sata_device     sata_dev; /* STP & directly attached */
+		struct ssp_device      ssp_dev;
         };
 
         void *lldd_dev;
@@ -389,6 +397,8 @@ struct sas_ha_struct {
 	unsigned long	  state;
 	spinlock_t	  lock;
 	int		  eh_active;
+	wait_queue_head_t eh_wait_q;
+	struct list_head  eh_dev_q;
 
 	struct mutex disco_mutex;