* 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
#include <linux/fs.h>
+#include "attrib.h"
#include "types.h"
+#include "inode.h"
#include "runlist.h"
#include "volume.h"
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 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
+ * @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 unlocked on entry and is
- * unlocked on return.
- * - This function takes the runlist lock of @vi for reading and
- * sometimes for writing and sometimes modifies the runlist.
+ * 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)
+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, FALSE);
+ return __ntfs_cluster_free(ni, start_vcn, count, ctx, FALSE);
}
extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
*
* Return 0 on success and -errno on error.
*
- * Locking: This function takes the volume lcn bitmap lock for writing and
- * modifies the bitmap contents.
+ * 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)
git://git.onelab.eu / linux-2.6.git / blobdiff