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 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 "runlist.h"
  32 #include "volume.h"
  33
  34 typedef enum {
  35         FIRST_ZONE      = 0,    /* For sanity checking. */
  36         MFT_ZONE        = 0,    /* Allocate from $MFT zone. */
  37         DATA_ZONE       = 1,    /* Allocate from $DATA zone. */
  38         LAST_ZONE       = 1,    /* For sanity checking. */
  39 } NTFS_CLUSTER_ALLOCATION_ZONES;
  40
  41 extern runlist_element *ntfs_cluster_alloc(ntfs_volume *vol,
  42                 const VCN start_vcn, const s64 count, const LCN start_lcn,
  43                 const NTFS_CLUSTER_ALLOCATION_ZONES zone);
  44
  45 extern s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn,
  46                 s64 count, const BOOL is_rollback);
  47
  48 /**
  49  * ntfs_cluster_free - free clusters on an ntfs volume
  50  * @vi:         vfs inode whose runlist describes the clusters to free
  51  * @start_vcn:  vcn in the runlist of @vi at which to start freeing clusters
  52  * @count:      number of clusters to free or -1 for all clusters
  53  *
  54  * Free @count clusters starting at the cluster @start_vcn in the runlist
  55  * described by the vfs inode @vi.
  56  *
  57  * If @count is -1, all clusters from @start_vcn to the end of the runlist are
  58  * deallocated.  Thus, to completely free all clusters in a runlist, use
  59  * @start_vcn = 0 and @count = -1.
  60  *
  61  * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
  62  * has to deal with it later.
  63  *
  64  * Return the number of deallocated clusters (not counting sparse ones) on
  65  * success and -errno on error.
  66  *
  67  * Locking: - The runlist described by @vi must be unlocked on entry and is
  68  *            unlocked on return.
  69  *          - This function takes the runlist lock of @vi for reading and
  70  *            sometimes for writing and sometimes modifies the runlist.
  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(struct inode *vi, const VCN start_vcn,
  77                 s64 count)
  78 {
  79         return __ntfs_cluster_free(vi, 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  */
  99 static inline int ntfs_cluster_free_from_rl(ntfs_volume *vol,
 100                 const runlist_element *rl)
 101 {
 102         int ret;
 103
 104         down_write(&vol->lcnbmp_lock);
 105         ret = ntfs_cluster_free_from_rl_nolock(vol, rl);
 106         up_write(&vol->lcnbmp_lock);
 107         return ret;
 108 }
 109
 110 #endif /* NTFS_RW */
 111
 112 #endif /* defined _LINUX_NTFS_LCNALLOC_H */