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Diffstat (limited to 'fs/ntfs/lcnalloc.h')
| -rw-r--r-- | fs/ntfs/lcnalloc.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/fs/ntfs/lcnalloc.h b/fs/ntfs/lcnalloc.h new file mode 100644 index 000000000..2adb04316 --- /dev/null +++ b/fs/ntfs/lcnalloc.h @@ -0,0 +1,145 @@ +/* + * lcnalloc.h - Exports for NTFS kernel cluster (de)allocation. Part of the + * Linux-NTFS project. + * + * Copyright (c) 2004-2005 Anton Altaparmakov + * + * 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_LCNALLOC_H +#define _LINUX_NTFS_LCNALLOC_H + +#ifdef NTFS_RW + +#include <linux/fs.h> + +#include "attrib.h" +#include "types.h" +#include "inode.h" +#include "runlist.h" +#include "volume.h" + +typedef enum { + FIRST_ZONE = 0, /* For sanity checking. */ + MFT_ZONE = 0, /* Allocate from $MFT zone. */ + DATA_ZONE = 1, /* Allocate from $DATA zone. */ + LAST_ZONE = 1, /* For sanity checking. */ +} NTFS_CLUSTER_ALLOCATION_ZONES; + +extern runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, + const VCN start_vcn, const s64 count, const LCN start_lcn, + const NTFS_CLUSTER_ALLOCATION_ZONES zone, + const bool is_extension); + +extern s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, + s64 count, ntfs_attr_search_ctx *ctx, const bool is_rollback); + +/** + * ntfs_cluster_free - free clusters on an ntfs volume + * @ni: ntfs inode whose runlist describes the clusters to free + * @start_vcn: vcn in the runlist of @ni at which to start freeing clusters + * @count: number of clusters to free or -1 for all clusters + * @ctx: active attribute search context if present or NULL if not + * + * Free @count clusters starting at the cluster @start_vcn in the runlist + * described by the ntfs inode @ni. + * + * If @count is -1, all clusters from @start_vcn to the end of the runlist are + * deallocated. Thus, to completely free all clusters in a runlist, use + * @start_vcn = 0 and @count = -1. + * + * If @ctx is specified, it is an active search context of @ni and its base mft + * record. This is needed when ntfs_cluster_free() encounters unmapped runlist + * fragments and allows their mapping. If you do not have the mft record + * mapped, you can specify @ctx as NULL and ntfs_cluster_free() will perform + * the necessary mapping and unmapping. + * + * Note, ntfs_cluster_free() saves the state of @ctx on entry and restores it + * before returning. Thus, @ctx will be left pointing to the same attribute on + * return as on entry. However, the actual pointers in @ctx may point to + * different memory locations on return, so you must remember to reset any + * cached pointers from the @ctx, i.e. after the call to ntfs_cluster_free(), + * you will probably want to do: + * m = ctx->mrec; + * a = ctx->attr; + * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that + * you cache ctx->mrec in a variable @m of type MFT_RECORD *. + * + * Note, ntfs_cluster_free() does not modify the runlist, so you have to remove + * from the runlist or mark sparse the freed runs later. + * + * Return the number of deallocated clusters (not counting sparse ones) on + * success and -errno on error. + * + * WARNING: If @ctx is supplied, regardless of whether success or failure is + * returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx + * is no longer valid, i.e. you need to either call + * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it. + * In that case PTR_ERR(@ctx->mrec) will give you the error code for + * why the mapping of the old inode failed. + * + * Locking: - The runlist described by @ni must be locked for writing on entry + * and is locked on return. Note the runlist may be modified when + * needed runlist fragments need to be mapped. + * - The volume lcn bitmap must be unlocked on entry and is unlocked + * on return. + * - This function takes the volume lcn bitmap lock for writing and + * modifies the bitmap contents. + * - If @ctx is NULL, the base mft record of @ni must not be mapped on + * entry and it will be left unmapped on return. + * - If @ctx is not NULL, the base mft record must be mapped on entry + * and it will be left mapped on return. + */ +static inline s64 ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, + s64 count, ntfs_attr_search_ctx *ctx) +{ + return __ntfs_cluster_free(ni, start_vcn, count, ctx, false); +} + +extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol, + const runlist_element *rl); + +/** + * ntfs_cluster_free_from_rl - free clusters from runlist + * @vol: mounted ntfs volume on which to free the clusters + * @rl: runlist describing the clusters to free + * + * Free all the clusters described by the runlist @rl on the volume @vol. In + * the case of an error being returned, at least some of the clusters were not + * freed. + * + * Return 0 on success and -errno on error. + * + * Locking: - This function takes the volume lcn bitmap lock for writing and + * modifies the bitmap contents. + * - The caller must have locked the runlist @rl for reading or + * writing. + */ +static inline int ntfs_cluster_free_from_rl(ntfs_volume *vol, + const runlist_element *rl) +{ + int ret; + + down_write(&vol->lcnbmp_lock); + ret = ntfs_cluster_free_from_rl_nolock(vol, rl); + up_write(&vol->lcnbmp_lock); + return ret; +} + +#endif /* NTFS_RW */ + +#endif /* defined _LINUX_NTFS_LCNALLOC_H */ |