fs/xfs/xfs_rmap_item.h

   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
  30 struct xfs_mount;
  31 struct kmem_zone;
  32
  33 /*
  34  * Max number of extents in fast allocation path.
  35  */
  36 #define XFS_RUI_MAX_FAST_EXTENTS        16
  37
  38 /*
  39  * Define RUI flag bits. Manipulated by set/clear/test_bit operators.
  40  */
  41 #define XFS_RUI_RECOVERED               1
  42
  43 /*
  44  * This is the "rmap update intent" log item.  It is used to log the fact that
  45  * some reverse mappings need to change.  It is used in conjunction with the
  46  * "rmap update done" log item described below.
  47  *
  48  * These log items follow the same rules as struct xfs_efi_log_item; see the
  49  * comments about that structure (in xfs_extfree_item.h) for more details.
  50  */
  51 struct xfs_rui_log_item {
  52         struct xfs_log_item             rui_item;
  53         atomic_t                        rui_refcount;
  54         atomic_t                        rui_next_extent;
  55         unsigned long                   rui_flags;      /* misc flags */
  56         struct xfs_rui_log_format       rui_format;
  57 };
  58
  59 static inline size_t
  60 xfs_rui_log_item_sizeof(
  61         unsigned int            nr)
  62 {
  63         return offsetof(struct xfs_rui_log_item, rui_format) +
  64                         xfs_rui_log_format_sizeof(nr);
  65 }
  66
  67 /*
  68  * This is the "rmap update done" log item.  It is used to log the fact that
  69  * some rmapbt updates mentioned in an earlier rui item have been performed.
  70  */
  71 struct xfs_rud_log_item {
  72         struct xfs_log_item             rud_item;
  73         struct xfs_rui_log_item         *rud_ruip;
  74         struct xfs_rud_log_format       rud_format;
  75 };
  76
  77 extern struct kmem_zone *xfs_rui_zone;
  78 extern struct kmem_zone *xfs_rud_zone;
  79
  80 struct xfs_rui_log_item *xfs_rui_init(struct xfs_mount *, uint);
  81 struct xfs_rud_log_item *xfs_rud_init(struct xfs_mount *,
  82                 struct xfs_rui_log_item *);
  83 int xfs_rui_copy_format(struct xfs_log_iovec *buf,
  84                 struct xfs_rui_log_format *dst_rui_fmt);
  85 void xfs_rui_item_free(struct xfs_rui_log_item *);
  86 void xfs_rui_release(struct xfs_rui_log_item *);
  87 int xfs_rui_recover(struct xfs_mount *mp, struct xfs_rui_log_item *ruip);
  88
  89 #endif  /* __XFS_RMAP_ITEM_H__ */