root/fs/xfs/libxfs/xfs_refcount.h

INCLUDED FROM

DEFINITIONS

1. xfs_refcount_max_unmap

   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 
   9 extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
  10                 xfs_agblock_t bno, int *stat);
  11 extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
  12                 xfs_agblock_t bno, int *stat);
  13 extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur,
  14                 xfs_agblock_t bno, int *stat);
  15 extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
  16                 struct xfs_refcount_irec *irec, int *stat);
  17 
  18 enum xfs_refcount_intent_type {
  19         XFS_REFCOUNT_INCREASE = 1,
  20         XFS_REFCOUNT_DECREASE,
  21         XFS_REFCOUNT_ALLOC_COW,
  22         XFS_REFCOUNT_FREE_COW,
  23 };
  24 
  25 struct xfs_refcount_intent {
  26         struct list_head                        ri_list;
  27         enum xfs_refcount_intent_type           ri_type;
  28         xfs_fsblock_t                           ri_startblock;
  29         xfs_extlen_t                            ri_blockcount;
  30 };
  31 
  32 void xfs_refcount_increase_extent(struct xfs_trans *tp,
  33                 struct xfs_bmbt_irec *irec);
  34 void xfs_refcount_decrease_extent(struct xfs_trans *tp,
  35                 struct xfs_bmbt_irec *irec);
  36 
  37 extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
  38                 struct xfs_btree_cur *rcur, int error);
  39 extern int xfs_refcount_finish_one(struct xfs_trans *tp,
  40                 enum xfs_refcount_intent_type type, xfs_fsblock_t startblock,
  41                 xfs_extlen_t blockcount, xfs_fsblock_t *new_fsb,
  42                 xfs_extlen_t *new_len, struct xfs_btree_cur **pcur);
  43 
  44 extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
  45                 xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
  46                 xfs_extlen_t *flen, bool find_end_of_shared);
  47 
  48 void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
  49                 xfs_extlen_t len);
  50 void xfs_refcount_free_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
  51                 xfs_extlen_t len);
  52 extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
  53                 xfs_agnumber_t agno);
  54 
  55 /*
  56  * While we're adjusting the refcounts records of an extent, we have
  57  * to keep an eye on the number of extents we're dirtying -- run too
  58  * many in a single transaction and we'll exceed the transaction's
  59  * reservation and crash the fs.  Each record adds 12 bytes to the
  60  * log (plus any key updates) so we'll conservatively assume 32 bytes
  61  * per record.  We must also leave space for btree splits on both ends
  62  * of the range and space for the CUD and a new CUI.
  63  */
  64 #define XFS_REFCOUNT_ITEM_OVERHEAD      32
  65 
  66 static inline xfs_fileoff_t xfs_refcount_max_unmap(int log_res)
  67 {
  68         return (log_res * 3 / 4) / XFS_REFCOUNT_ITEM_OVERHEAD;
  69 }
  70 
  71 extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
  72                 xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
  73 union xfs_btree_rec;
  74 extern void xfs_refcount_btrec_to_irec(union xfs_btree_rec *rec,
  75                 struct xfs_refcount_irec *irec);
  76 extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
  77                 struct xfs_refcount_irec *irec, int *stat);
  78 
  79 #endif  /* __XFS_REFCOUNT_H__ */