[CIFS] Fix oops in experimental notify code (when CONFIG_CIFS_EXPERIMENTAL

was turned on).

Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/CHANGES

@@ -8,7 +8,8 @@ allowing an SMBs TCP length to be up to a few bytes longer than it should be.
 wsize and rsize can now be larger than negotiated buffer size if server
 supports large readx/writex, even when directio mount flag not specified.
 Write size will in many cases now be 16K instead of 4K which greatly helps
-file copy performance on lightly loaded networks.
+file copy performance on lightly loaded networks.  Fix oops in dnotify
+when experimental config flag enabled.
 
 Version 1.37
 ------------

fs/cifs/README

@@ -296,6 +296,8 @@ A partial list of the supported mount options follows:
 		unused.
   rsize		default read size (usually 16K)
   wsize		default write size (usually 16K, 32K is often better over GigE)
+		maximum wsize currently allowed by CIFS is 57344 (14 4096 byte
+		pages)
   rw		mount the network share read-write (note that the
 		server may still consider the share read-only)
   ro		mount network share read-only

fs/cifs/cifsfs.c

@@ -901,6 +901,10 @@ init_cifs(void)
 	INIT_LIST_HEAD(&GlobalSMBSessionList);
 	INIT_LIST_HEAD(&GlobalTreeConnectionList);
 	INIT_LIST_HEAD(&GlobalOplock_Q);
+#ifdef CONFIG_CIFS_EXPERIMENTAL
+	INIT_LIST_HEAD(&GlobalDnotifyReqList);
+	INIT_LIST_HEAD(&GlobalDnotifyRsp_Q);
+#endif	
 /*
  *  Initialize Global counters
  */

fs/cifs/fcntl.c

@@ -78,6 +78,10 @@ int cifs_dir_notify(struct file * file, unsigned long arg)
 	__u32 filter = FILE_NOTIFY_CHANGE_NAME | FILE_NOTIFY_CHANGE_ATTRIBUTES;
 	__u16 netfid;
 
+
+	if(experimEnabled == 0)
+		return 0;
+
 	xid = GetXid();
 	cifs_sb = CIFS_SB(file->f_dentry->d_sb);
 	pTcon = cifs_sb->tcon;