From: Jeff Layton <jlayton@redhat.com>
Date: Sun, 5 Jul 2009 15:01:02 +0000 (-0400)
Subject: cifs: fix regression with O_EXCL creates and optimize away lookup
X-Git-Tag: v2.6.30.4~53
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9d33821d65cdad2af0461f3a6268125cc8a33052;p=thirdparty%2Fkernel%2Fstable.git

cifs: fix regression with O_EXCL creates and optimize away lookup

commit 5ddf1e0ff00fd808c048d0b920784828276cc516 upstream.

cifs: fix regression with O_EXCL creates and optimize away lookup

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Shirish Pargaonkar <shirishp@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 3758965d73d56..83440ca44c039 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -641,6 +641,15 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 			}
 	}
 
+	/*
+	 * O_EXCL: optimize away the lookup, but don't hash the dentry. Let
+	 * the VFS handle the create.
+	 */
+	if (nd->flags & LOOKUP_EXCL) {
+		d_instantiate(direntry, NULL);
+		return 0;
+	}
+
 	/* can not grab the rename sem here since it would
 	deadlock in the cases (beginning of sys_rename itself)
 	in which we already have the sb rename sem */