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_extfree_item.h (2622B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (c) 2000,2005 Silicon Graphics, Inc.
      4 * All Rights Reserved.
      5 */
      6#ifndef	__XFS_EXTFREE_ITEM_H__
      7#define	__XFS_EXTFREE_ITEM_H__
      8
      9/* kernel only EFI/EFD definitions */
     10
     11struct xfs_mount;
     12struct kmem_cache;
     13
     14/*
     15 * Max number of extents in fast allocation path.
     16 */
     17#define	XFS_EFI_MAX_FAST_EXTENTS	16
     18
     19/*
     20 * This is the "extent free intention" log item.  It is used to log the fact
     21 * that some extents need to be free.  It is used in conjunction with the
     22 * "extent free done" log item described below.
     23 *
     24 * The EFI is reference counted so that it is not freed prior to both the EFI
     25 * and EFD being committed and unpinned. This ensures the EFI is inserted into
     26 * the AIL even in the event of out of order EFI/EFD processing. In other words,
     27 * an EFI is born with two references:
     28 *
     29 * 	1.) an EFI held reference to track EFI AIL insertion
     30 * 	2.) an EFD held reference to track EFD commit
     31 *
     32 * On allocation, both references are the responsibility of the caller. Once the
     33 * EFI is added to and dirtied in a transaction, ownership of reference one
     34 * transfers to the transaction. The reference is dropped once the EFI is
     35 * inserted to the AIL or in the event of failure along the way (e.g., commit
     36 * failure, log I/O error, etc.). Note that the caller remains responsible for
     37 * the EFD reference under all circumstances to this point. The caller has no
     38 * means to detect failure once the transaction is committed, however.
     39 * Therefore, an EFD is required after this point, even in the event of
     40 * unrelated failure.
     41 *
     42 * Once an EFD is allocated and dirtied in a transaction, reference two
     43 * transfers to the transaction. The EFD reference is dropped once it reaches
     44 * the unpin handler. Similar to the EFI, the reference also drops in the event
     45 * of commit failure or log I/O errors. Note that the EFD is not inserted in the
     46 * AIL, so at this point both the EFI and EFD are freed.
     47 */
     48struct xfs_efi_log_item {
     49	struct xfs_log_item	efi_item;
     50	atomic_t		efi_refcount;
     51	atomic_t		efi_next_extent;
     52	xfs_efi_log_format_t	efi_format;
     53};
     54
     55/*
     56 * This is the "extent free done" log item.  It is used to log
     57 * the fact that some extents earlier mentioned in an efi item
     58 * have been freed.
     59 */
     60struct xfs_efd_log_item {
     61	struct xfs_log_item	efd_item;
     62	struct xfs_efi_log_item *efd_efip;
     63	uint			efd_next_extent;
     64	xfs_efd_log_format_t	efd_format;
     65};
     66
     67/*
     68 * Max number of extents in fast allocation path.
     69 */
     70#define	XFS_EFD_MAX_FAST_EXTENTS	16
     71
     72extern struct kmem_cache	*xfs_efi_cache;
     73extern struct kmem_cache	*xfs_efd_cache;
     74
     75#endif	/* __XFS_EXTFREE_ITEM_H__ */