1 /* 2 * runlist.h - Defines for runlist handling in NTFS Linux kernel driver. 3 * Part of the Linux-NTFS project. 4 * 5 * Copyright (c) 2001-2004 Anton Altaparmakov 6 * Copyright (c) 2002 Richard Russon 7 * 8 * This program/include file is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as published 10 * by the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program/include file is distributed in the hope that it will be 14 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty 15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program (in the main directory of the Linux-NTFS 20 * distribution in the file COPYING); if not, write to the Free Software 21 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22 */ 23 24 #ifndef _LINUX_NTFS_RUNLIST_H 25 #define _LINUX_NTFS_RUNLIST_H 26 27 #include "types.h" 28 #include "layout.h" 29 #include "volume.h" 30 31 /** 32 * runlist_element - in memory vcn to lcn mapping array element 33 * @vcn: starting vcn of the current array element 34 * @lcn: starting lcn of the current array element 35 * @length: length in clusters of the current array element 36 * 37 * The last vcn (in fact the last vcn + 1) is reached when length == 0. 38 * 39 * When lcn == -1 this means that the count vcns starting at vcn are not 40 * physically allocated (i.e. this is a hole / data is sparse). 41 */ 42 typedef struct { /* In memory vcn to lcn mapping structure element. */ 43 VCN vcn; /* vcn = Starting virtual cluster number. */ 44 LCN lcn; /* lcn = Starting logical cluster number. */ 45 s64 length; /* Run length in clusters. */ 46 } runlist_element; 47 48 /** 49 * runlist - in memory vcn to lcn mapping array including a read/write lock 50 * @rl: pointer to an array of runlist elements 51 * @lock: read/write spinlock for serializing access to @rl 52 * 53 */ 54 typedef struct { 55 runlist_element *rl; 56 struct rw_semaphore lock; 57 } runlist; 58 59 static inline void ntfs_init_runlist(runlist *rl) 60 { 61 rl->rl = NULL; 62 init_rwsem(&rl->lock); 63 } 64 65 typedef enum { 66 LCN_HOLE = -1, /* Keep this as highest value or die! */ 67 LCN_RL_NOT_MAPPED = -2, 68 LCN_ENOENT = -3, 69 } LCN_SPECIAL_VALUES; 70 71 extern runlist_element *ntfs_runlists_merge(runlist_element *drl, 72 runlist_element *srl); 73 74 extern runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol, 75 const ATTR_RECORD *attr, runlist_element *old_rl); 76 77 extern LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn); 78 79 extern int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol, 80 const runlist_element *rl, const VCN start_vcn); 81 82 extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst, 83 const int dst_len, const runlist_element *rl, 84 const VCN start_vcn, VCN *const stop_vcn); 85 86 extern int ntfs_rl_truncate_nolock(const ntfs_volume *vol, 87 runlist *const runlist, const s64 new_length); 88 89 #endif /* _LINUX_NTFS_RUNLIST_H */ 90