-/*
- * yaffs_bg_gc()
- * Garbage collects. Intended to be called from a background thread.
- * Returns non-zero if at least half the free chunks are erased.
- */
-int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
-{
- int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
-
- T(YAFFS_TRACE_BACKGROUND, (TSTR("Background gc %u" TENDSTR), urgency));
-
- yaffs_check_gc(dev, 1);
- return erased_chunks > dev->n_free_chunks / 2;
-}
-
-/*------------------------- TAGS --------------------------------*/
-
-static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
- int chunk_obj)
-{
- return (tags->chunk_id == chunk_obj &&
- tags->obj_id == obj_id && !tags->is_deleted) ? 1 : 0;
-
-}
-
-/*-------------------- Data file manipulation -----------------*/
-
-static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
- struct yaffs_ext_tags *tags)
-{
- /*Get the Tnode, then get the level 0 offset chunk offset */
- struct yaffs_tnode *tn;
- int the_chunk = -1;
- struct yaffs_ext_tags local_tags;
- int ret_val = -1;
-
- struct yaffs_dev *dev = in->my_dev;
-
- if (!tags) {
- /* Passed a NULL, so use our own tags space */
- tags = &local_tags;
- }
-
- tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
-
- if (tn) {
- the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
-
- ret_val =
- yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
- inode_chunk);
- }
- return ret_val;
-}
-
-static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
- struct yaffs_ext_tags *tags)
-{
- /* Get the Tnode, then get the level 0 offset chunk offset */
- struct yaffs_tnode *tn;
- int the_chunk = -1;
- struct yaffs_ext_tags local_tags;
-
- struct yaffs_dev *dev = in->my_dev;
- int ret_val = -1;
-
- if (!tags) {
- /* Passed a NULL, so use our own tags space */
- tags = &local_tags;
- }
-
- tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
-
- if (tn) {
-
- the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
-
- ret_val =
- yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
- inode_chunk);
-
- /* Delete the entry in the filestructure (if found) */
- if (ret_val != -1)
- yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
- }
-
- return ret_val;
-}
-
-int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
- int nand_chunk, int in_scan)
-{
- /* NB in_scan is zero unless scanning.
- * For forward scanning, in_scan is > 0;
- * for backward scanning in_scan is < 0
- *
- * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
- */
-
- struct yaffs_tnode *tn;
- struct yaffs_dev *dev = in->my_dev;
- int existing_cunk;
- struct yaffs_ext_tags existing_tags;
- struct yaffs_ext_tags new_tags;
- unsigned existing_serial, new_serial;
-
- if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
- /* Just ignore an attempt at putting a chunk into a non-file during scanning
- * If it is not during Scanning then something went wrong!
- */
- if (!in_scan) {
- T(YAFFS_TRACE_ERROR,
- (TSTR
- ("yaffs tragedy:attempt to put data chunk into a non-file"
- TENDSTR)));
- YBUG();
- }
-
- yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
- return YAFFS_OK;
- }
-
- tn = yaffs_add_find_tnode_0(dev,
- &in->variant.file_variant,
- inode_chunk, NULL);
- if (!tn)
- return YAFFS_FAIL;
-
- if (!nand_chunk)
- /* Dummy insert, bail now */
- return YAFFS_OK;
-
- existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
-
- if (in_scan != 0) {
- /* If we're scanning then we need to test for duplicates
- * NB This does not need to be efficient since it should only ever
- * happen when the power fails during a write, then only one
- * chunk should ever be affected.
- *
- * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
- * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
- */
-
- if (existing_cunk > 0) {
- /* NB Right now existing chunk will not be real chunk_id if the chunk group size > 1
- * thus we have to do a FindChunkInFile to get the real chunk id.
- *
- * We have a duplicate now we need to decide which one to use:
- *
- * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
- * Forward scanning YAFFS2: The new one is what we use, dump the old one.
- * YAFFS1: Get both sets of tags and compare serial numbers.
- */
-
- if (in_scan > 0) {
- /* Only do this for forward scanning */
- yaffs_rd_chunk_tags_nand(dev,
- nand_chunk,
- NULL, &new_tags);
-
- /* Do a proper find */
- existing_cunk =
- yaffs_find_chunk_in_file(in, inode_chunk,
- &existing_tags);
- }
-
- if (existing_cunk <= 0) {
- /*Hoosterman - how did this happen? */
-
- T(YAFFS_TRACE_ERROR,
- (TSTR
- ("yaffs tragedy: existing chunk < 0 in scan"
- TENDSTR)));
-
- }
-
- /* NB The deleted flags should be false, otherwise the chunks will
- * not be loaded during a scan
- */
-
- if (in_scan > 0) {
- new_serial = new_tags.serial_number;
- existing_serial = existing_tags.serial_number;
- }
-
- if ((in_scan > 0) &&
- (existing_cunk <= 0 ||
- ((existing_serial + 1) & 3) == new_serial)) {
- /* Forward scanning.
- * Use new
- * Delete the old one and drop through to update the tnode
- */
- yaffs_chunk_del(dev, existing_cunk, 1,
- __LINE__);
- } else {
- /* Backward scanning or we want to use the existing one
- * Use existing.
- * Delete the new one and return early so that the tnode isn't changed
- */
- yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
- return YAFFS_OK;
- }
- }
-
- }
-
- if (existing_cunk == 0)
- in->n_data_chunks++;