// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) International Business Machines Corp., 2006
*
* Author: Artem Bityutskiy (Битюцкий Артём)
*/
/*
* The UBI Eraseblock Association (EBA) sub-system.
*
* This sub-system is responsible for I/O to/from logical eraseblock.
*
* Although in this implementation the EBA table is fully kept and managed in
* RAM, which assumes poor scalability, it might be (partially) maintained on
* flash in future implementations.
*
* The EBA sub-system implements per-logical eraseblock locking. Before
* accessing a logical eraseblock it is locked for reading or writing. The
* per-logical eraseblock locking is implemented by means of the lock tree. The
* lock tree is an RB-tree which refers all the currently locked logical
* eraseblocks. The lock tree elements are &struct ubi_ltree_entry objects.
* They are indexed by (@vol_id, @lnum) pairs.
*
* EBA also maintains the global sequence counter which is incremented each
* time a logical eraseblock is mapped to a physical eraseblock and it is
* stored in the volume identifier header. This means that each VID header has
* a unique sequence number. The sequence number is only increased an we assume
* 64 bits is enough to never overflow.
*/
#include <linux/sla
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