fs: dcache documentation cleanup

	char *(*d_dname)(struct dentry *, char *, int);

};

/* the dentry parameter passed to d_hash and d_compare is the parent

/*

 * Locking rules for dentry_operations callbacks are to be found in

 * Documentation/filesystems/Locking. Keep it updated!

 *

 * the dentry parameter passed to d_hash and d_compare is the parent

 * directory of the entries to be compared. It is used in case these

 * functions need any directory specific information for determining

 * equivalency classes.  Using the dentry itself might not work, as it

 * might be a negative dentry which has no information associated with

 * it */

/*

locking rules:

		big lock	dcache_lock	d_lock   may block

d_revalidate:	no		no		no       yes

d_hash		no		no		no       yes

d_compare:	no		yes		yes      no

d_delete:	no		yes		no       no

d_release:	no		no		no       yes

d_iput:		no		no		no       yes

 * it.

 */

/* d_flags entries */