From b7fb222b8acb13672fe37ba1da79f75263781edf Mon Sep 17 00:00:00 2001
From: wang di <di.wang@intel.com>
Date: Sun, 1 Feb 2015 21:52:14 -0500
Subject: [PATCH] staging/lustre/fld: refer to MDT0 for fld lookup in some
 cases

It is possible that when fld client is trying to lookup seq
on one of MDT, but the connection between the client and the MDT
is not being initialized yet, especially during striped dir creation,
because client will only send create req to the master MDT, then
master MDT will distribute the operation to all of other MDT, instead
of client distributing these requests, which will usually trigger
the connection.

In this case, we will send the fld request to MDT0, since it has
all of location information.

Signed-off-by: wang di <di.wang@intel.com>
Reviewed-on: http://review.whamcloud.com/11780
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4855
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/lustre/lustre/fld/fld_request.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/staging/lustre/lustre/fld/fld_request.c b/drivers/staging/lustre/lustre/fld/fld_request.c
index 7801db0e79ce..b8d17e109a96 100644
--- a/drivers/staging/lustre/lustre/fld/fld_request.c
+++ b/drivers/staging/lustre/lustre/fld/fld_request.c
@@ -131,11 +131,20 @@ fld_rrb_scan(struct lu_client_fld *fld, u64 seq)
 	else
 		hash = 0;
 
+again:
 	list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 		if (target->ft_idx == hash)
 			return target;
 	}
 
+	if (hash != 0) {
+		/* It is possible the remote target(MDT) are not connected to
+		 * with client yet, so we will refer this to MDT0, which should
+		 * be connected during mount */
+		hash = 0;
+		goto again;
+	}
+
 	CERROR("%s: Can't find target by hash %d (seq %#llx). Targets (%d):\n",
 		fld->lcf_name, hash, seq, fld->lcf_count);
 
-- 
2.34.1