+ /* Now, move those elements to the tail of the list so we get something
+ * else next time. */
+ if (off) {
+ struct tdb_free_record oldhrec, newhrec, oldtrec, newtrec;
+ tdb_off_t oldhoff, oldtoff, newtoff;
+
+ /* The record we were up to is the new head. */
+ ecode = tdb_read_convert(tdb, off, &newhrec, sizeof(newhrec));
+ if (ecode != TDB_SUCCESS)
+ goto unlock_err;
+
+ /* Get the new tail. */
+ newtoff = frec_prev(&newhrec);
+ ecode = tdb_read_convert(tdb, newtoff, &newtrec,
+ sizeof(newtrec));
+ if (ecode != TDB_SUCCESS)
+ goto unlock_err;
+
+ /* Get the old head. */
+ oldhoff = tdb_read_off(tdb, b_off);
+ if (TDB_OFF_IS_ERR(oldhoff)) {
+ ecode = oldhoff;
+ goto unlock_err;
+ }
+
+ /* This could happen if they all coalesced away. */
+ if (oldhoff == off)
+ goto out;
+
+ ecode = tdb_read_convert(tdb, oldhoff, &oldhrec,
+ sizeof(oldhrec));
+ if (ecode != TDB_SUCCESS)
+ goto unlock_err;
+
+ /* Get the old tail. */
+ oldtoff = frec_prev(&oldhrec);
+ ecode = tdb_read_convert(tdb, oldtoff, &oldtrec,
+ sizeof(oldtrec));
+ if (ecode != TDB_SUCCESS)
+ goto unlock_err;
+
+ /* Old tail's next points to old head. */
+ oldtrec.next = oldhoff;
+
+ /* Old head's prev points to old tail. */
+ oldhrec.magic_and_prev
+ = (TDB_FREE_MAGIC << (64 - TDB_OFF_UPPER_STEAL))
+ | oldtoff;
+
+ /* New tail's next is 0. */
+ newtrec.next = 0;
+
+ /* Write out the modified versions. */
+ ecode = tdb_write_convert(tdb, oldtoff, &oldtrec,
+ sizeof(oldtrec));
+ if (ecode != TDB_SUCCESS)
+ goto unlock_err;
+
+ ecode = tdb_write_convert(tdb, oldhoff, &oldhrec,
+ sizeof(oldhrec));
+ if (ecode != TDB_SUCCESS)
+ goto unlock_err;
+
+ ecode = tdb_write_convert(tdb, newtoff, &newtrec,
+ sizeof(newtrec));
+ if (ecode != TDB_SUCCESS)
+ goto unlock_err;
+
+ /* And finally link in new head. */
+ ecode = tdb_write_off(tdb, b_off, off);
+ if (ecode != TDB_SUCCESS)
+ goto unlock_err;
+ }
+out: