cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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xfs_rmap_item.h (2433B)

      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 * Copyright (C) 2016 Oracle.  All Rights Reserved.
      4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
      5 */
      6#ifndef	__XFS_RMAP_ITEM_H__
      7#define	__XFS_RMAP_ITEM_H__
      8
      9/*
     10 * There are (currently) three pairs of rmap btree redo item types: map, unmap,
     11 * and convert.  The common abbreviations for these are RUI (rmap update
     12 * intent) and RUD (rmap update done).  The redo item type is encoded in the
     13 * flags field of each xfs_map_extent.
     14 *
     15 * *I items should be recorded in the *first* of a series of rolled
     16 * transactions, and the *D items should be recorded in the same transaction
     17 * that records the associated rmapbt updates.  Typically, the first
     18 * transaction will record a bmbt update, followed by some number of
     19 * transactions containing rmapbt updates, and finally transactions with any
     20 * bnobt/cntbt updates.
     21 *
     22 * Should the system crash after the commit of the first transaction but
     23 * before the commit of the final transaction in a series, log recovery will
     24 * use the redo information recorded by the intent items to replay the
     25 * (rmapbt/bnobt/cntbt) metadata updates in the non-first transaction.
     26 */
     27
     28/* kernel only RUI/RUD definitions */
     29
     30struct xfs_mount;
     31struct kmem_cache;
     32
     33/*
     34 * Max number of extents in fast allocation path.
     35 */
     36#define	XFS_RUI_MAX_FAST_EXTENTS	16
     37
     38/*
     39 * This is the "rmap update intent" log item.  It is used to log the fact that
     40 * some reverse mappings need to change.  It is used in conjunction with the
     41 * "rmap update done" log item described below.
     42 *
     43 * These log items follow the same rules as struct xfs_efi_log_item; see the
     44 * comments about that structure (in xfs_extfree_item.h) for more details.
     45 */
     46struct xfs_rui_log_item {
     47	struct xfs_log_item		rui_item;
     48	atomic_t			rui_refcount;
     49	atomic_t			rui_next_extent;
     50	struct xfs_rui_log_format	rui_format;
     51};
     52
     53static inline size_t
     54xfs_rui_log_item_sizeof(
     55	unsigned int		nr)
     56{
     57	return offsetof(struct xfs_rui_log_item, rui_format) +
     58			xfs_rui_log_format_sizeof(nr);
     59}
     60
     61/*
     62 * This is the "rmap update done" log item.  It is used to log the fact that
     63 * some rmapbt updates mentioned in an earlier rui item have been performed.
     64 */
     65struct xfs_rud_log_item {
     66	struct xfs_log_item		rud_item;
     67	struct xfs_rui_log_item		*rud_ruip;
     68	struct xfs_rud_log_format	rud_format;
     69};
     70
     71extern struct kmem_cache	*xfs_rui_cache;
     72extern struct kmem_cache	*xfs_rud_cache;
     73
     74#endif	/* __XFS_RMAP_ITEM_H__ */