* @count: number of clusters to allocate
* @start_lcn: starting lcn at which to allocate the clusters (or -1 if none)
* @zone: zone from which to allocate the clusters
+ * @is_extension: if 'true', this is an attribute extension
*
* Allocate @count clusters preferably starting at cluster @start_lcn or at the
* current allocator position if @start_lcn is -1, on the mounted ntfs volume
* @start_vcn specifies the vcn of the first allocated cluster. This makes
* merging the resulting runlist with the old runlist easier.
*
+ * If @is_extension is 'true', the caller is allocating clusters to extend an
+ * attribute and if it is 'false', the caller is allocating clusters to fill a
+ * hole in an attribute. Practically the difference is that if @is_extension
+ * is 'true' the returned runlist will be terminated with LCN_ENOENT and if
+ * @is_extension is 'false' the runlist will be terminated with
+ * LCN_RL_NOT_MAPPED.
+ *
* You need to check the return value with IS_ERR(). If this is false, the
* function was successful and the return value is a runlist describing the
* allocated cluster(s). If IS_ERR() is true, the function failed and
*/
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)
{
LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn;
LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size;
continue;
}
bit = 1 << (lcn & 7);
- ntfs_debug("bit %i.", bit);
+ ntfs_debug("bit 0x%x.", bit);
/* If the bit is already set, go onto the next one. */
if (*byte & bit) {
lcn++;
/* Add runlist terminator element. */
if (likely(rl)) {
rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length;
- rl[rlpos].lcn = LCN_RL_NOT_MAPPED;
+ rl[rlpos].lcn = is_extension ? LCN_ENOENT : LCN_RL_NOT_MAPPED;
rl[rlpos].length = 0;
}
if (likely(page && !IS_ERR(page))) {
* @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
* @is_rollback: true if this is a rollback operation
*
* Free @count clusters starting at the cluster @start_vcn in the runlist
* deallocated. Thus, to completely free all clusters in a runlist, use
* @start_vcn = 0 and @count = -1.
*
- * @is_rollback should always be FALSE, it is for internal use to rollback
+ * 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 *.
+ *
+ * @is_rollback should always be 'false', it is for internal use to rollback
* errors. You probably want to use ntfs_cluster_free() instead.
*
- * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
- * has to deal with it later.
+ * 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.
* 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.
*/
s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count,
- const BOOL is_rollback)
+ ntfs_attr_search_ctx *ctx, const bool is_rollback)
{
s64 delta, to_free, total_freed, real_freed;
ntfs_volume *vol;
total_freed = real_freed = 0;
- rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, TRUE);
+ rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, ctx);
if (IS_ERR(rl)) {
if (!is_rollback)
ntfs_error(vol->sb, "Failed to find first runlist "
/* Attempt to map runlist. */
vcn = rl->vcn;
- rl = ntfs_attr_find_vcn_nolock(ni, vcn, TRUE);
+ rl = ntfs_attr_find_vcn_nolock(ni, vcn, ctx);
if (IS_ERR(rl)) {
err = PTR_ERR(rl);
if (!is_rollback)
* If rollback fails, set the volume errors flag, emit an error
* message, and return the error code.
*/
- delta = __ntfs_cluster_free(ni, start_vcn, total_freed, TRUE);
+ delta = __ntfs_cluster_free(ni, start_vcn, total_freed, ctx, true);
if (delta < 0) {
ntfs_error(vol->sb, "Failed to rollback (error %i). Leaving "
"inconsistent metadata! Unmount and run "
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff