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Diffstat (limited to 'fs/ntfs/runlist.h')
| -rw-r--r-- | fs/ntfs/runlist.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/fs/ntfs/runlist.h b/fs/ntfs/runlist.h new file mode 100644 index 000000000000..7107fde59df9 --- /dev/null +++ b/fs/ntfs/runlist.h @@ -0,0 +1,89 @@ +/* + * runlist.h - Defines for runlist handling in NTFS Linux kernel driver. + * Part of the Linux-NTFS project. + * + * Copyright (c) 2001-2004 Anton Altaparmakov + * Copyright (c) 2002 Richard Russon + * + * This program/include file is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program/include file is distributed in the hope that it will be + * useful, but WITHOUT ANY WARRANTY; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program (in the main directory of the Linux-NTFS + * distribution in the file COPYING); if not, write to the Free Software + * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef _LINUX_NTFS_RUNLIST_H +#define _LINUX_NTFS_RUNLIST_H + +#include "types.h" +#include "layout.h" +#include "volume.h" + +/** + * runlist_element - in memory vcn to lcn mapping array element + * @vcn: starting vcn of the current array element + * @lcn: starting lcn of the current array element + * @length: length in clusters of the current array element + * + * The last vcn (in fact the last vcn + 1) is reached when length == 0. + * + * When lcn == -1 this means that the count vcns starting at vcn are not + * physically allocated (i.e. this is a hole / data is sparse). + */ +typedef struct { /* In memory vcn to lcn mapping structure element. */ + VCN vcn; /* vcn = Starting virtual cluster number. */ + LCN lcn; /* lcn = Starting logical cluster number. */ + s64 length; /* Run length in clusters. */ +} runlist_element; + +/** + * runlist - in memory vcn to lcn mapping array including a read/write lock + * @rl: pointer to an array of runlist elements + * @lock: read/write spinlock for serializing access to @rl + * + */ +typedef struct { + runlist_element *rl; + struct rw_semaphore lock; +} runlist; + +static inline void ntfs_init_runlist(runlist *rl) +{ + rl->rl = NULL; + init_rwsem(&rl->lock); +} + +typedef enum { + LCN_HOLE = -1, /* Keep this as highest value or die! */ + LCN_RL_NOT_MAPPED = -2, + LCN_ENOENT = -3, +} LCN_SPECIAL_VALUES; + +extern runlist_element *ntfs_runlists_merge(runlist_element *drl, + runlist_element *srl); + +extern runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol, + const ATTR_RECORD *attr, runlist_element *old_rl); + +extern LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn); + +extern int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol, + const runlist_element *rl, const VCN start_vcn); + +extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst, + const int dst_len, const runlist_element *rl, + const VCN start_vcn, VCN *const stop_vcn); + +extern int ntfs_rl_truncate_nolock(const ntfs_volume *vol, + runlist *const runlist, const s64 new_length); + +#endif /* _LINUX_NTFS_RUNLIST_H */ |