fs/xfs/xfs_extfree_item.h

   1 /*
   2  * Copyright (c) 2000,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_EXTFREE_ITEM_H__
  19 #define __XFS_EXTFREE_ITEM_H__
  20
  21 /* kernel only EFI/EFD definitions */
  22
  23 struct xfs_mount;
  24 struct kmem_zone;
  25
  26 /*
  27  * Max number of extents in fast allocation path.
  28  */
  29 #define XFS_EFI_MAX_FAST_EXTENTS        16
  30
  31 /*
  32  * Define EFI flag bits. Manipulated by set/clear/test_bit operators.
  33  */
  34 #define XFS_EFI_RECOVERED       1
  35
  36 /*
  37  * This is the "extent free intention" log item.  It is used to log the fact
  38  * that some extents need to be free.  It is used in conjunction with the
  39  * "extent free done" log item described below.
  40  *
  41  * The EFI is reference counted so that it is not freed prior to both the EFI
  42  * and EFD being committed and unpinned. This ensures that when the last
  43  * reference goes away the EFI will always be in the AIL as it has been
  44  * unpinned, regardless of whether the EFD is processed before or after the EFI.
  45  */
  46 typedef struct xfs_efi_log_item {
  47         xfs_log_item_t          efi_item;
  48         atomic_t                efi_refcount;
  49         atomic_t                efi_next_extent;
  50         unsigned long           efi_flags;      /* misc flags */
  51         xfs_efi_log_format_t    efi_format;
  52 } xfs_efi_log_item_t;
  53
  54 /*
  55  * This is the "extent free done" log item.  It is used to log
  56  * the fact that some extents earlier mentioned in an efi item
  57  * have been freed.
  58  */
  59 typedef struct xfs_efd_log_item {
  60         xfs_log_item_t          efd_item;
  61         xfs_efi_log_item_t      *efd_efip;
  62         uint                    efd_next_extent;
  63         xfs_efd_log_format_t    efd_format;
  64 } xfs_efd_log_item_t;
  65
  66 /*
  67  * Max number of extents in fast allocation path.
  68  */
  69 #define XFS_EFD_MAX_FAST_EXTENTS        16
  70
  71 extern struct kmem_zone *xfs_efi_zone;
  72 extern struct kmem_zone *xfs_efd_zone;
  73
  74 xfs_efi_log_item_t      *xfs_efi_init(struct xfs_mount *, uint);
  75 xfs_efd_log_item_t      *xfs_efd_init(struct xfs_mount *, xfs_efi_log_item_t *,
  76                                       uint);
  77 int                     xfs_efi_copy_format(xfs_log_iovec_t *buf,
  78                                             xfs_efi_log_format_t *dst_efi_fmt);
  79 void                    xfs_efi_item_free(xfs_efi_log_item_t *);
  80
  81 #endif  /* __XFS_EXTFREE_ITEM_H__ */