From 965a0f7a75ef0011062413a6fa62ab6404e0b1ea Mon Sep 17 00:00:00 2001
From: Michael Brown
Date: Mon, 10 Aug 2009 02:20:21 +0100
Subject: [infiniband] Allow SRP reconnection attempts even after reporting
 failures

With iSCSI, connection attempts are expensive; it may take many
seconds to determine that a connection will fail.  SRP connection
attempts are much less expensive, so we may as well avoid the
"optimisation" of declaring a state of permanent failure after a
certain number of attempts.  This allows a gPXE SRP initiator to
resume operations after an arbitrary amount of SRP target downtime.
---
 src/drivers/block/srp.c | 17 +++++------------
 src/include/gpxe/srp.h  |  6 ------
 2 files changed, 5 insertions(+), 18 deletions(-)

diff --git a/src/drivers/block/srp.c b/src/drivers/block/srp.c
index f50f194b..1d0799ab 100644
--- a/src/drivers/block/srp.c
+++ b/src/drivers/block/srp.c
@@ -80,19 +80,16 @@ static void srp_fail ( struct srp_device *srp, int rc ) {
 	/* Clear session state */
 	srp->state = 0;
 
-	/* Increment retry count */
-	srp->retry_count++;
-
-	/* If we have reached the retry limit, permanently abort the
-	 * session.
-	 */
+	/* If we have reached the retry limit, report the failure */
 	if ( srp->retry_count >= SRP_MAX_RETRIES ) {
-		srp->instant_rc = rc;
 		srp_scsi_done ( srp, rc );
 		return;
 	}
 
-	/* Otherwise, try to reopen the connection */
+	/* Otherwise, increment the retry count and try to reopen the
+	 * connection
+	 */
+	srp->retry_count++;
 	srp_login ( srp );
 }
 
@@ -445,10 +442,6 @@ static int srp_command ( struct scsi_device *scsi,
 	struct srp_device *srp =
 		container_of ( scsi->backend, struct srp_device, refcnt );
 
-	/* Return instant failure, if we have already aborted the session */
-	if ( srp->instant_rc )
-		return srp->instant_rc;
-
 	/* Store SCSI command */
 	if ( srp->command ) {
 		DBGC ( srp, "SRP %p cannot handle concurrent SCSI commands\n",
diff --git a/src/include/gpxe/srp.h b/src/include/gpxe/srp.h
index 75ec7b83..85f39b93 100644
--- a/src/include/gpxe/srp.h
+++ b/src/include/gpxe/srp.h
@@ -828,12 +828,6 @@ struct srp_device {
 	unsigned int state;
 	/** Retry counter */
 	unsigned int retry_count;
-	/** Instant return status code
-	 *
-	 * Used to avoid retrying the connection on every new SCSI
-	 * command after the retry count has been exceeded.
-	 */
-	int instant_rc;
 	/** Current SCSI command */
 	struct scsi_command *command;
 
-- 
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