From: Mikhail Pershin <mpershin@whamcloud.com>
Date: Thu, 30 May 2019 09:30:43 +0000 (+0300)
Subject: LU-12120 grants: prevent negative ted_grant value
X-Git-Tag: 2.12.3-RC1~179
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F84%2F35084%2F2;p=fs%2Flustre-release.git

LU-12120 grants: prevent negative ted_grant value

Add check in tgt_grant_shrink() to protect ted_grant
against negative value.

Lustre-change: https://review.whamcloud.com/34996
Lustre-commit: 7e08317ef5cbed5cd587017cbe343eb4cc52822c

Signed-off-by: Mikhail Pershin <mpershin@whamcloud.com>
Change-Id: Iddea86f052124413ac60f5d0f26bcb68e376ede5
Reviewed-by: Quentin Bouget <quentin.bouget@cea.fr>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/35084
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
---

diff --git a/lustre/target/tgt_grant.c b/lustre/target/tgt_grant.c
index f6ee8d1..e832bc9 100644
--- a/lustre/target/tgt_grant.c
+++ b/lustre/target/tgt_grant.c
@@ -605,6 +605,14 @@ static void tgt_grant_shrink(struct obd_export *exp, struct obdo *oa,
 
 	grant_shrink = oa->o_grant;
 
+	if (ted->ted_grant < grant_shrink) {
+		CDEBUG(D_CACHE,
+		       "%s: cli %s/%p wants %lu shrinked > grant %lu\n",
+		       obd->obd_name, exp->exp_client_uuid.uuid, exp,
+		       grant_shrink, ted->ted_grant);
+		grant_shrink = ted->ted_grant;
+	}
+
 	ted->ted_grant -= grant_shrink;
 	tgd->tgd_tot_granted -= grant_shrink;