--- /dev/null
+/*
+ * 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 */
Code Review / kvmfornfv.git / blobdiff