[SCSI] scsi_transport_fc: Introduce helper function for blocking scsi_eh

Move the duplicated code from FC LLDs to SCSI FC transport class.

Acked-by: James Smart <james.smart@emulex.com>
Acked-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Acked-by: Abhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 26 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index f436e033adaf..3ce56b3b2cd7 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -27,6 +27,7 @@
  */
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/delay.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_transport.h>
@@ -3144,6 +3145,31 @@ fc_scsi_scan_rport(struct work_struct *work)
         spin_unlock_irqrestore(shost->host_lock, flags);
 }
 
+/**
+ * fc_block_scsi_eh - Block SCSI eh thread for blocked fc_rport
+ * @cmnd: SCSI command that scsi_eh is trying to recover
+ *
+ * This routine can be called from a FC LLD scsi_eh callback. It
+ * blocks the scsi_eh thread until the fc_rport leaves the
+ * FC_PORTSTATE_BLOCKED. This is necessary to avoid the scsi_eh
+ * failing recovery actions for blocked rports which would lead to
+ * offlined SCSI devices.
+ */
+void fc_block_scsi_eh(struct scsi_cmnd *cmnd)
+{
+        struct Scsi_Host *shost = cmnd->device->host;
+        struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device));
+        unsigned long flags;
+
+        spin_lock_irqsave(shost->host_lock, flags);
+        while (rport->port_state == FC_PORTSTATE_BLOCKED) {
+                spin_unlock_irqrestore(shost->host_lock, flags);
+                msleep(1000);
+                spin_lock_irqsave(shost->host_lock, flags);
+        }
+        spin_unlock_irqrestore(shost->host_lock, flags);
+}
+EXPORT_SYMBOL(fc_block_scsi_eh);
 
 /**
  * fc_vport_setup - allocates and creates a FC virtual port.