fs/xfs/libxfs/xfs_refcount.h

   1 /*
   2  * Copyright (C) 2016 Oracle.  All Rights Reserved.
   3  *
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it would be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write the Free Software Foundation,
  18  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
  19  */
  20 #ifndef __XFS_REFCOUNT_H__
  21 #define __XFS_REFCOUNT_H__
  22
  23 extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
  24                 xfs_agblock_t bno, int *stat);
  25 extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
  26                 xfs_agblock_t bno, int *stat);
  27 extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
  28                 struct xfs_refcount_irec *irec, int *stat);
  29
  30 enum xfs_refcount_intent_type {
  31         XFS_REFCOUNT_INCREASE = 1,
  32         XFS_REFCOUNT_DECREASE,
  33         XFS_REFCOUNT_ALLOC_COW,
  34         XFS_REFCOUNT_FREE_COW,
  35 };
  36
  37 struct xfs_refcount_intent {
  38         struct list_head                        ri_list;
  39         enum xfs_refcount_intent_type           ri_type;
  40         xfs_fsblock_t                           ri_startblock;
  41         xfs_extlen_t                            ri_blockcount;
  42 };
  43
  44 extern int xfs_refcount_increase_extent(struct xfs_mount *mp,
  45                 struct xfs_defer_ops *dfops, struct xfs_bmbt_irec *irec);
  46 extern int xfs_refcount_decrease_extent(struct xfs_mount *mp,
  47                 struct xfs_defer_ops *dfops, struct xfs_bmbt_irec *irec);
  48
  49 extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
  50                 struct xfs_btree_cur *rcur, int error);
  51 extern int xfs_refcount_finish_one(struct xfs_trans *tp,
  52                 struct xfs_defer_ops *dfops, enum xfs_refcount_intent_type type,
  53                 xfs_fsblock_t startblock, xfs_extlen_t blockcount,
  54                 xfs_fsblock_t *new_fsb, xfs_extlen_t *new_len,
  55                 struct xfs_btree_cur **pcur);
  56
  57 extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
  58                 xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
  59                 xfs_extlen_t *flen, bool find_end_of_shared);
  60
  61 extern int xfs_refcount_alloc_cow_extent(struct xfs_mount *mp,
  62                 struct xfs_defer_ops *dfops, xfs_fsblock_t fsb,
  63                 xfs_extlen_t len);
  64 extern int xfs_refcount_free_cow_extent(struct xfs_mount *mp,
  65                 struct xfs_defer_ops *dfops, xfs_fsblock_t fsb,
  66                 xfs_extlen_t len);
  67 extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
  68                 xfs_agnumber_t agno);
  69
  70 /*
  71  * While we're adjusting the refcounts records of an extent, we have
  72  * to keep an eye on the number of extents we're dirtying -- run too
  73  * many in a single transaction and we'll exceed the transaction's
  74  * reservation and crash the fs.  Each record adds 12 bytes to the
  75  * log (plus any key updates) so we'll conservatively assume 32 bytes
  76  * per record.  We must also leave space for btree splits on both ends
  77  * of the range and space for the CUD and a new CUI.
  78  */
  79 #define XFS_REFCOUNT_ITEM_OVERHEAD      32
  80
  81 static inline xfs_fileoff_t xfs_refcount_max_unmap(int log_res)
  82 {
  83         return (log_res * 3 / 4) / XFS_REFCOUNT_ITEM_OVERHEAD;
  84 }
  85
  86 #endif  /* __XFS_REFCOUNT_H__ */