staging: lustre: ptlrpc: do not switch out-of-date context

When trying to replace a dead sec context with a new one, we must
ensure the new context is already up-to-date.
If it is not the case, just return from sptlrpc_req_replace_dead_ctx()
and come later when the new context has been updated.

Signed-off-by: Sebastien Buisson <sebastien.buisson@bull.net>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6536
Reviewed-on: http://review.whamcloud.com/15708
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ptlrpc/sec.c

@@ -515,6 +515,13 @@ static int sptlrpc_req_replace_dead_ctx(struct ptlrpc_request *req)
 
 		set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(msecs_to_jiffies(MSEC_PER_SEC));
+	} else if (unlikely(!test_bit(PTLRPC_CTX_UPTODATE_BIT, &newctx->cc_flags))) {
+		/*
+		 * new ctx not up to date yet
+		 */
+		CDEBUG(D_SEC,
+		       "ctx (%p, fl %lx) doesn't switch, not up to date yet\n",
+		       newctx, newctx->cc_flags);
 	} else {
 		/*
 		 * it's possible newctx == oldctx if we're switching