cifs: add tcon field to cifsFileInfo struct

Eventually, we'll have more than one tcon per superblock. At that point,
we'll need to know which one is associated with a particular fid. For
now, this is just set from the cifs_sb->tcon pointer, but eventually
the caller of cifs_new_fileinfo will pass a tcon pointer in.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifsglob.h

@@ -351,6 +351,7 @@ struct cifsFileInfo {
 	struct file *pfile; /* needed for writepage */
 	struct inode *pInode; /* needed for oplock break */
 	struct vfsmount *mnt;
+	struct cifsTconInfo *tcon;
 	struct mutex lock_mutex;
 	struct list_head llist; /* list of byte range locks we have. */
 	bool closePend:1;	/* file is marked to close */

fs/cifs/dir.c

@@ -150,6 +150,7 @@ cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle,
 	pCifsFile->pfile = file;
 	pCifsFile->invalidHandle = false;
 	pCifsFile->closePend = false;
+	pCifsFile->tcon = cifs_sb->tcon;
 	mutex_init(&pCifsFile->fh_mutex);
 	mutex_init(&pCifsFile->lock_mutex);
 	INIT_LIST_HEAD(&pCifsFile->llist);