!1146 [sync] PR-1136: gfs2: Don't deref jdesc in evict

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/1136 
 
PR sync from: ZhaoLong Wang <wangzhaolong1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/ID2Q7S2KSELYENBGS2BVZCEVGEP4WKO2/ 
 
 
Link:https://gitee.com/openeuler/kernel/pulls/1146 

Reviewed-by: zhangyi (F) <yi.zhang@huawei.com> 
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> 

fs/gfs2/super.c

@@ -1412,6 +1412,14 @@ static void gfs2_evict_inode(struct inode *inode)
 	if (inode->i_nlink || sb_rdonly(sb))
 		goto out;
 
+	/*
+	 * In case of an incomplete mount, gfs2_evict_inode() may be called for
+	 * system files without having an active journal to write to.  In that
+	 * case, skip the filesystem evict.
+	 */
+	if (!sdp->sd_jdesc)
+		goto out;
+
 	gfs2_holder_mark_uninitialized(&gh);
 	ret = evict_should_delete(inode, &gh);
 	if (ret == SHOULD_DEFER_EVICTION)