[CIFS] Add support for posix open during lookup

This patch by utilizing lookup intents, and thus removing a network
roundtrip in the open path, improves performance dramatically on
open (30% or more) to Samba and other servers which support the
cifs posix extensions

Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 7ae1986..df40ab6 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -350,7 +350,7 @@
 	bool invalidHandle:1;	/* file closed via session abend */
 	bool messageMode:1;	/* for pipes: message vs byte mode */
 	atomic_t wrtPending;   /* handle in use - defer close */
-	struct semaphore fh_sem; /* prevents reopen race after dead ses*/
+	struct mutex fh_mutex; /* prevents reopen race after dead ses*/
 	struct cifs_search_info srch_inf;
 };