From: Robin Humble <plaguedbypenguins@gmail.com>
Date: Thu, 9 Aug 2018 05:33:04 +0000 (+1000)
Subject: LU-11227 lod: lod_sync: don't attempt sync to inactive targets
X-Git-Tag: 2.10.6-RC1~13
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=refs%2Fchanges%2F91%2F32991%2F4;p=fs%2Flustre-release.git

LU-11227 lod: lod_sync: don't attempt sync to inactive targets

chgrp on a client triggers lod_sync() which in turn loops over OST/MDT
targets with dt_sync(). dt_sync() fails with -ENOTCONN when targets
have been deactivated (ie. set to active=0). The client retries
infinitely causing the client process to hang and considerably MDS
network traffic, load, and disk i/o.

the fix is to not attempt dt_sync() to ost/mdt targets that have been
deactivated and also (because of possible races) to ignore connection
errors.

tested with Lustre 2.10.4.

Signed-off-by: Robin Humble <plaguedbypenguins@gmail.com>
Change-Id: I617509cf7944541489f4fd9762c233b771132165
Reviewed-on: https://review.whamcloud.com/32991
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
---

diff --git a/lustre/lod/lod_dev.c b/lustre/lod/lod_dev.c
index cf31d19..0a153bd 100644
--- a/lustre/lod/lod_dev.c
+++ b/lustre/lod/lod_dev.c
@@ -1394,11 +1394,16 @@ static int lod_sync(const struct lu_env *env, struct dt_device *dev)
 	lod_foreach_ost(lod, i) {
 		ost = OST_TGT(lod, i);
 		LASSERT(ost && ost->ltd_ost);
+		if (!ost->ltd_active)
+			continue;
 		rc = dt_sync(env, ost->ltd_ost);
 		if (rc) {
-			CERROR("%s: can't sync ost %u: %d\n",
-			       lod2obd(lod)->obd_name, i, rc);
-			break;
+			if (rc != -ENOTCONN) {
+				CERROR("%s: can't sync ost %u: %d\n",
+				       lod2obd(lod)->obd_name, i, rc);
+				break;
+			}
+			rc = 0;
 		}
 	}
 	lod_putref(lod, &lod->lod_ost_descs);
@@ -1410,11 +1415,16 @@ static int lod_sync(const struct lu_env *env, struct dt_device *dev)
 	lod_foreach_mdt(lod, i) {
 		mdt = MDT_TGT(lod, i);
 		LASSERT(mdt && mdt->ltd_mdt);
+		if (!mdt->ltd_active)
+			continue;
 		rc = dt_sync(env, mdt->ltd_mdt);
 		if (rc) {
-			CERROR("%s: can't sync mdt %u: %d\n",
-			       lod2obd(lod)->obd_name, i, rc);
-			break;
+			if (rc != -ENOTCONN) {
+				CERROR("%s: can't sync mdt %u: %d\n",
+				       lod2obd(lod)->obd_name, i, rc);
+				break;
+			}
+			rc = 0;
 		}
 	}
 	lod_putref(lod, &lod->lod_mdt_descs);