From: Benjamin Coddington <bcodding@redhat.com>
Date: Wed, 17 Feb 2016 15:41:41 +0000 (-0500)
Subject: NFSv4: Fix a dentry leak on alias use
X-Git-Tag: firefly_0821_release~176^2~475^2~120
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b8558ada696e26f51cbde1d24cdf291bbc7ec79b;p=firefly-linux-kernel-4.4.55.git

NFSv4: Fix a dentry leak on alias use

commit d9dfd8d741683347ee159d25f5b50c346a0df557 upstream.

In the case where d_add_unique() finds an appropriate alias to use it will
have already incremented the reference count.  An additional dget() to swap
the open context's dentry is unnecessary and will leak a reference.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Fixes: 275bb307865a3 ("NFSv4: Move dentry instantiation into the NFSv4-...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index f496ed721d27..98a44157353a 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2461,9 +2461,9 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata,
 		dentry = d_add_unique(dentry, igrab(state->inode));
 		if (dentry == NULL) {
 			dentry = opendata->dentry;
-		} else if (dentry != ctx->dentry) {
+		} else {
 			dput(ctx->dentry);
-			ctx->dentry = dget(dentry);
+			ctx->dentry = dentry;
 		}
 		nfs_set_verifier(dentry,
 				nfs_save_change_attribute(d_inode(opendata->dir)));