LXR linux/fs/xfs/libxfs/xfs

   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_REFCOUNT_H__
   7#define __XFS_REFCOUNT_H__
   8
   9struct xfs_trans;
  10struct xfs_mount;
  11struct xfs_perag;
  12struct xfs_btree_cur;
  13struct xfs_bmbt_irec;
  14struct xfs_refcount_irec;
  15
  16extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
  17                xfs_agblock_t bno, int *stat);
  18extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
  19                xfs_agblock_t bno, int *stat);
  20extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur,
  21                xfs_agblock_t bno, int *stat);
  22extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
  23                struct xfs_refcount_irec *irec, int *stat);
  24
  25enum xfs_refcount_intent_type {
  26        XFS_REFCOUNT_INCREASE = 1,
  27        XFS_REFCOUNT_DECREASE,
  28        XFS_REFCOUNT_ALLOC_COW,
  29        XFS_REFCOUNT_FREE_COW,
  30};
  31
  32struct xfs_refcount_intent {
  33        struct list_head                        ri_list;
  34        enum xfs_refcount_intent_type           ri_type;
  35        xfs_extlen_t                            ri_blockcount;
  36        xfs_fsblock_t                           ri_startblock;
  37};
  38
  39void xfs_refcount_increase_extent(struct xfs_trans *tp,
  40                struct xfs_bmbt_irec *irec);
  41void xfs_refcount_decrease_extent(struct xfs_trans *tp,
  42                struct xfs_bmbt_irec *irec);
  43
  44extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
  45                struct xfs_btree_cur *rcur, int error);
  46extern int xfs_refcount_finish_one(struct xfs_trans *tp,
  47                enum xfs_refcount_intent_type type, xfs_fsblock_t startblock,
  48                xfs_extlen_t blockcount, xfs_fsblock_t *new_fsb,
  49                xfs_extlen_t *new_len, struct xfs_btree_cur **pcur);
  50
  51extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
  52                xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
  53                xfs_extlen_t *flen, bool find_end_of_shared);
  54
  55void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
  56                xfs_extlen_t len);
  57void xfs_refcount_free_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
  58                xfs_extlen_t len);
  59extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
  60                struct xfs_perag *pag);
  61
  62/*
  63 * While we're adjusting the refcounts records of an extent, we have
  64 * to keep an eye on the number of extents we're dirtying -- run too
  65 * many in a single transaction and we'll exceed the transaction's
  66 * reservation and crash the fs.  Each record adds 12 bytes to the
  67 * log (plus any key updates) so we'll conservatively assume 32 bytes
  68 * per record.  We must also leave space for btree splits on both ends
  69 * of the range and space for the CUD and a new CUI.
  70 *
  71 * Each EFI that we attach to the transaction is assumed to consume ~32 bytes.
  72 * This is a low estimate for an EFI tracking a single extent (16 bytes for the
  73 * EFI header, 16 for the extent, and 12 for the xlog op header), but the
  74 * estimate is acceptable if there's more than one extent being freed.
  75 * In the worst case of freeing every other block during a refcount decrease
  76 * operation, we amortize the space used for one EFI log item across 16
  77 * extents.
  78 */
  79#define XFS_REFCOUNT_ITEM_OVERHEAD      32
  80
  81extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
  82                xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
  83union xfs_btree_rec;
  84extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
  85                struct xfs_refcount_irec *irec);
  86extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
  87                struct xfs_refcount_irec *irec, int *stat);
  88
  89extern struct kmem_cache        *xfs_refcount_intent_cache;
  90
  91int __init xfs_refcount_intent_init_cache(void);
  92void xfs_refcount_intent_destroy_cache(void);
  93
  94#endif  /* __XFS_REFCOUNT_H__ */
  95