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 "attrib.h" 31 #include "types.h" 32 #include "inode.h" 33 #include "runlist.h" 34 #include "volume.h" 35 36 typedef enum { 37 FIRST_ZONE = 0, /* For sanity checking. */ 38 MFT_ZONE = 0, /* Allocate from $MFT zone. */ 39 DATA_ZONE = 1, /* Allocate from $DATA zone. */ 40 LAST_ZONE = 1, /* For sanity checking. */ 41 } NTFS_CLUSTER_ALLOCATION_ZONES; 42 43 extern runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, 44 const VCN start_vcn, const s64 count, const LCN start_lcn, 45 const NTFS_CLUSTER_ALLOCATION_ZONES zone, 46 const bool is_extension); 47 48 extern s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, 49 s64 count, ntfs_attr_search_ctx *ctx, const bool is_rollback); 50 51 /** 52 * ntfs_cluster_free - free clusters on an ntfs volume 53 * @ni: ntfs inode whose runlist describes the clusters to free 54 * @start_vcn: vcn in the runlist of @ni at which to start freeing clusters 55 * @count: number of clusters to free or -1 for all clusters 56 * @ctx: active attribute search context if present or NULL if not 57 * 58 * Free @count clusters starting at the cluster @start_vcn in the runlist 59 * described by the ntfs inode @ni. 60 * 61 * If @count is -1, all clusters from @start_vcn to the end of the runlist are 62 * deallocated. Thus, to completely free all clusters in a runlist, use 63 * @start_vcn = 0 and @count = -1. 64 * 65 * If @ctx is specified, it is an active search context of @ni and its base mft 66 * record. This is needed when ntfs_cluster_free() encounters unmapped runlist 67 * fragments and allows their mapping. If you do not have the mft record 68 * mapped, you can specify @ctx as NULL and ntfs_cluster_free() will perform 69 * the necessary mapping and unmapping. 70 * 71 * Note, ntfs_cluster_free() saves the state of @ctx on entry and restores it 72 * before returning. Thus, @ctx will be left pointing to the same attribute on 73 * return as on entry. However, the actual pointers in @ctx may point to 74 * different memory locations on return, so you must remember to reset any 75 * cached pointers from the @ctx, i.e. after the call to ntfs_cluster_free(), 76 * you will probably want to do: 77 * m = ctx->mrec; 78 * a = ctx->attr; 79 * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that 80 * you cache ctx->mrec in a variable @m of type MFT_RECORD *. 81 * 82 * Note, ntfs_cluster_free() does not modify the runlist, so you have to remove 83 * from the runlist or mark sparse the freed runs later. 84 * 85 * Return the number of deallocated clusters (not counting sparse ones) on 86 * success and -errno on error. 87 * 88 * WARNING: If @ctx is supplied, regardless of whether success or failure is 89 * returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx 90 * is no longer valid, i.e. you need to either call 91 * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it. 92 * In that case PTR_ERR(@ctx->mrec) will give you the error code for 93 * why the mapping of the old inode failed. 94 * 95 * Locking: - The runlist described by @ni must be locked for writing on entry 96 * and is locked on return. Note the runlist may be modified when 97 * needed runlist fragments need to be mapped. 98 * - The volume lcn bitmap must be unlocked on entry and is unlocked 99 * on return. 100 * - This function takes the volume lcn bitmap lock for writing and 101 * modifies the bitmap contents. 102 * - If @ctx is NULL, the base mft record of @ni must not be mapped on 103 * entry and it will be left unmapped on return. 104 * - If @ctx is not NULL, the base mft record must be mapped on entry 105 * and it will be left mapped on return. 106 */ 107 static inline s64 ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, 108 s64 count, ntfs_attr_search_ctx *ctx) 109 { 110 return __ntfs_cluster_free(ni, start_vcn, count, ctx, false); 111 } 112 113 extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol, 114 const runlist_element *rl); 115 116 /** 117 * ntfs_cluster_free_from_rl - free clusters from runlist 118 * @vol: mounted ntfs volume on which to free the clusters 119 * @rl: runlist describing the clusters to free 120 * 121 * Free all the clusters described by the runlist @rl on the volume @vol. In 122 * the case of an error being returned, at least some of the clusters were not 123 * freed. 124 * 125 * Return 0 on success and -errno on error. 126 * 127 * Locking: - This function takes the volume lcn bitmap lock for writing and 128 * modifies the bitmap contents. 129 * - The caller must have locked the runlist @rl for reading or 130 * writing. 131 */ 132 static inline int ntfs_cluster_free_from_rl(ntfs_volume *vol, 133 const runlist_element *rl) 134 { 135 int ret; 136 137 down_write(&vol->lcnbmp_lock); 138 ret = ntfs_cluster_free_from_rl_nolock(vol, rl); 139 up_write(&vol->lcnbmp_lock); 140 return ret; 141 } 142 143 #endif /* NTFS_RW */ 144 145 #endif /* defined _LINUX_NTFS_LCNALLOC_H */ 146