From patchwork Wed Jul  8 21:58:27 2009
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Subject: lookup create with O_EXCL patch merged
From: Steve French <smfrench@gmail.com>
X-Patchwork-Id: 29609
Message-Id: <524f69650907081458y6b6301e0mc2340f0f8a36b8bc@mail.gmail.com>
To: linux-cifs-client@lists.samba.org
Date: Wed, 8 Jul 2009 16:58:27 -0500

Now that it has been tested by Shirish, merged Jeff's patch into cifs-2.6.git

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>
CC: Stable Kernel <stable@kernel.org>

---
in which we already have the sb rename sem */

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index a40054f..ff55fc6 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -643,6 +643,15 @@ 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)