From: Hongchao Zhang <hongchao.zhang@intel.com>
Date: Sat, 13 Jan 2018 10:08:29 +0000 (+0800)
Subject: LU-8346 obdclass: protect key_set_version
X-Git-Tag: 2.10.4-RC1~112
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=823e1549f109412db4a8cb31e648819660c5f7b8;p=fs%2Flustre-release.git

LU-8346 obdclass: protect key_set_version

In lu_context_refill, the key_set_version should be protected
before comparing it to version stored in the lu_context.

This patch is a supplement of the previous patch
https://review.whamcloud.com/#/c/28405/, which adds protection
for key_set_version from modification in lu_context_refill
and lu_context_key_degister.

Lustre-change: https://review.whamcloud.com/27448
Lustre-commit: 4538de675cc1ee05408fa912e71c65d9109d7027

Change-Id: I201f56214382a717cfc31ba573e06fec9fbedae4
Signed-off-by: Hongchao Zhang <hongchao.zhang@intel.com>
Reviewed-by: Patrick Farrell <paf@cray.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Signed-off-by: Minh Diep <minh.diep@intel.com>
Reviewed-on: https://review.whamcloud.com/31017
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
---

diff --git a/lustre/obdclass/lu_object.c b/lustre/obdclass/lu_object.c
index 751e3d1..f6a043b 100644
--- a/lustre/obdclass/lu_object.c
+++ b/lustre/obdclass/lu_object.c
@@ -1407,8 +1407,8 @@ void lu_context_key_degister(struct lu_context_key *key)
 
 	lu_context_key_quiesce(key);
 
-	++key_set_version;
 	write_lock(&lu_keys_guard);
+	++key_set_version;
 	key_fini(&lu_shrink_env.le_ctx, key->lct_index);
 
 	/**
@@ -1778,7 +1778,14 @@ EXPORT_SYMBOL(lu_context_exit);
  */
 int lu_context_refill(struct lu_context *ctx)
 {
-        return likely(ctx->lc_version == key_set_version) ? 0 : keys_fill(ctx);
+	read_lock(&lu_keys_guard);
+	if (likely(ctx->lc_version == key_set_version)) {
+		read_unlock(&lu_keys_guard);
+		return 0;
+	}
+
+	read_unlock(&lu_keys_guard);
+	return keys_fill(ctx);
 }
 
 /**