diff options
Diffstat (limited to 'fs/ntfs/lcnalloc.h')
| -rw-r--r-- | fs/ntfs/lcnalloc.h | 64 |
1 files changed, 47 insertions, 17 deletions
diff --git a/fs/ntfs/lcnalloc.h b/fs/ntfs/lcnalloc.h index e4d7fb98d68..72cbca7003b 100644 --- a/fs/ntfs/lcnalloc.h +++ b/fs/ntfs/lcnalloc.h @@ -2,7 +2,7 @@ * lcnalloc.h - Exports for NTFS kernel cluster (de)allocation. Part of the * Linux-NTFS project. * - * Copyright (c) 2004 Anton Altaparmakov + * 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 @@ -27,7 +27,9 @@ #include <linux/fs.h> +#include "attrib.h" #include "types.h" +#include "inode.h" #include "runlist.h" #include "volume.h" @@ -40,44 +42,72 @@ typedef enum { 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 NTFS_CLUSTER_ALLOCATION_ZONES zone, + const BOOL is_extension); -extern s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, - s64 count, const BOOL write_locked, const BOOL is_rollback); +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 - * @vi: vfs inode whose runlist describes the clusters to free - * @start_vcn: vcn in the runlist of @vi at which to start freeing clusters + * @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 - * @write_locked: true if the runlist is locked for writing + * @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 vfs inode @vi. + * 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. * - * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller - * has to deal with it later. + * 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. * - * Locking: - The runlist described by @vi must be locked on entry and is - * locked on return. Note if the runlist is locked for reading the - * lock may be dropped and reacquired. Note the runlist may be - * modified when needed runlist fragments need to be mapped. + * 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(struct inode *vi, const VCN start_vcn, - s64 count, const BOOL write_locked) +static inline s64 ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, + s64 count, ntfs_attr_search_ctx *ctx) { - return __ntfs_cluster_free(vi, start_vcn, count, write_locked, FALSE); + return __ntfs_cluster_free(ni, start_vcn, count, ctx, FALSE); } extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol, |