fs/ntfs/lcnalloc.h

   1 /*
   2  * lcnalloc.h - Exports for NTFS kernel cluster (de)allocation.  Part of the
   3  *              Linux-NTFS project.
   4  *
   5  * Copyright (c) 2004-2005 Anton Altaparmakov
   6  *
   7  * This program/include file is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program/include file is distributed in the hope that it will be
  13  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program (in the main directory of the Linux-NTFS
  19  * distribution in the file COPYING); if not, write to the Free Software
  20  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #ifndef _LINUX_NTFS_LCNALLOC_H
  24 #define _LINUX_NTFS_LCNALLOC_H
  25
  26 #ifdef NTFS_RW
  27
  28 #include <linux/fs.h>
  29
  30 #include "types.h"
  31 #include "inode.h"
  32 #include "runlist.h"
  33 #include "volume.h"
  34
  35 typedef enum {
  36         FIRST_ZONE      = 0,    /* For sanity checking. */
  37         MFT_ZONE        = 0,    /* Allocate from $MFT zone. */
  38         DATA_ZONE       = 1,    /* Allocate from $DATA zone. */
  39         LAST_ZONE       = 1,    /* For sanity checking. */
  40 } NTFS_CLUSTER_ALLOCATION_ZONES;
  41
  42 extern runlist_element *ntfs_cluster_alloc(ntfs_volume *vol,
  43                 const VCN start_vcn, const s64 count, const LCN start_lcn,
  44                 const NTFS_CLUSTER_ALLOCATION_ZONES zone);
  45
  46 extern s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn,
  47                 s64 count, const BOOL is_rollback);
  48
  49 /**
  50  * ntfs_cluster_free - free clusters on an ntfs volume
  51  * @ni:         ntfs inode whose runlist describes the clusters to free
  52  * @start_vcn:  vcn in the runlist of @ni at which to start freeing clusters
  53  * @count:      number of clusters to free or -1 for all clusters
  54  *
  55  * Free @count clusters starting at the cluster @start_vcn in the runlist
  56  * described by the ntfs inode @ni.
  57  *
  58  * If @count is -1, all clusters from @start_vcn to the end of the runlist are
  59  * deallocated.  Thus, to completely free all clusters in a runlist, use
  60  * @start_vcn = 0 and @count = -1.
  61  *
  62  * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
  63  * has to deal with it later.
  64  *
  65  * Return the number of deallocated clusters (not counting sparse ones) on
  66  * success and -errno on error.
  67  *
  68  * Locking: - The runlist described by @ni must be locked for writing on entry
  69  *            and is locked on return.  Note the runlist may be modified when
  70  *            needed runlist fragments need to be mapped.
  71  *          - The volume lcn bitmap must be unlocked on entry and is unlocked
  72  *            on return.
  73  *          - This function takes the volume lcn bitmap lock for writing and
  74  *            modifies the bitmap contents.
  75  */
  76 static inline s64 ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn,
  77                 s64 count)
  78 {
  79         return __ntfs_cluster_free(ni, start_vcn, count, FALSE);
  80 }
  81
  82 extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
  83                 const runlist_element *rl);
  84
  85 /**
  86  * ntfs_cluster_free_from_rl - free clusters from runlist
  87  * @vol:        mounted ntfs volume on which to free the clusters
  88  * @rl:         runlist describing the clusters to free
  89  *
  90  * Free all the clusters described by the runlist @rl on the volume @vol.  In
  91  * the case of an error being returned, at least some of the clusters were not
  92  * freed.
  93  *
  94  * Return 0 on success and -errno on error.
  95  *
  96  * Locking: - This function takes the volume lcn bitmap lock for writing and
  97  *            modifies the bitmap contents.
  98  *          - The caller must have locked the runlist @rl for reading or
  99  *            writing.
 100  */
 101 static inline int ntfs_cluster_free_from_rl(ntfs_volume *vol,
 102                 const runlist_element *rl)
 103 {
 104         int ret;
 105
 106         down_write(&vol->lcnbmp_lock);
 107         ret = ntfs_cluster_free_from_rl_nolock(vol, rl);
 108         up_write(&vol->lcnbmp_lock);
 109         return ret;
 110 }
 111
 112 #endif /* NTFS_RW */
 113
 114 #endif /* defined _LINUX_NTFS_LCNALLOC_H */