From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Ashish Sangwan <ashishsangwan2@gmail.com>,
        Anna Schumaker <Anna.Schumaker@Netapp.com>
Subject: [PATCH 4.9 050/117] NFS: fix nfs_path in case of a rename retry
Date:   Mon,  9 Nov 2020 13:54:36 +0100
Message-Id: <20201109125028.043674257@linuxfoundation.org>
In-Reply-To: <20201109125025.630721781@linuxfoundation.org>
References: <20201109125025.630721781@linuxfoundation.org>
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From: Ashish Sangwan <ashishsangwan2@gmail.com>

commit 247db73560bc3e5aef6db50c443c3c0db115bc93 upstream.

We are generating incorrect path in case of rename retry because
we are restarting from wrong dentry. We should restart from the
dentry which was received in the call to nfs_path.

CC: stable@vger.kernel.org
Signed-off-by: Ashish Sangwan <ashishsangwan2@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/namespace.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -30,9 +30,9 @@ int nfs_mountpoint_expiry_timeout = 500
 /*
  * nfs_path - reconstruct the path given an arbitrary dentry
  * @base - used to return pointer to the end of devname part of path
- * @dentry - pointer to dentry
+ * @dentry_in - pointer to dentry
  * @buffer - result buffer
- * @buflen - length of buffer
+ * @buflen_in - length of buffer
  * @flags - options (see below)
  *
  * Helper function for constructing the server pathname
@@ -47,15 +47,19 @@ int nfs_mountpoint_expiry_timeout = 500
  *		       the original device (export) name
  *		       (if unset, the original name is returned verbatim)
  */
-char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen,
-	       unsigned flags)
+char *nfs_path(char **p, struct dentry *dentry_in, char *buffer,
+	       ssize_t buflen_in, unsigned flags)
 {
 	char *end;
 	int namelen;
 	unsigned seq;
 	const char *base;
+	struct dentry *dentry;
+	ssize_t buflen;
 
 rename_retry:
+	buflen = buflen_in;
+	dentry = dentry_in;
 	end = buffer+buflen;
 	*--end = '\0';
 	buflen--;