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-rw-r--r--fs/yaffs2/yaffs_yaffs2.c1532
1 files changed, 1532 insertions, 0 deletions
diff --git a/fs/yaffs2/yaffs_yaffs2.c b/fs/yaffs2/yaffs_yaffs2.c
new file mode 100644
index 0000000000..f1dc972276
--- /dev/null
+++ b/fs/yaffs2/yaffs_yaffs2.c
@@ -0,0 +1,1532 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2011 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+#include "yaffs_yaffs2.h"
+#include "yaffs_checkptrw.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_nand.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_verify.h"
+#include "yaffs_attribs.h"
+#include "yaffs_summary.h"
+
+/*
+ * Checkpoints are really no benefit on very small partitions.
+ *
+ * To save space on small partitions don't bother with checkpoints unless
+ * the partition is at least this big.
+ */
+#define YAFFS_CHECKPOINT_MIN_BLOCKS 60
+#define YAFFS_SMALL_HOLE_THRESHOLD 4
+
+/*
+ * Oldest Dirty Sequence Number handling.
+ */
+
+/* yaffs_calc_oldest_dirty_seq()
+ * yaffs2_find_oldest_dirty_seq()
+ * Calculate the oldest dirty sequence number if we don't know it.
+ */
+void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev)
+{
+ int i;
+ unsigned seq;
+ unsigned block_no = 0;
+ struct yaffs_block_info *b;
+
+ if (!dev->param.is_yaffs2)
+ return;
+
+ /* Find the oldest dirty sequence number. */
+ seq = dev->seq_number + 1;
+ b = dev->block_info;
+ for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+ if (b->block_state == YAFFS_BLOCK_STATE_FULL &&
+ (b->pages_in_use - b->soft_del_pages) <
+ dev->param.chunks_per_block &&
+ b->seq_number < seq) {
+ seq = b->seq_number;
+ block_no = i;
+ }
+ b++;
+ }
+
+ if (block_no) {
+ dev->oldest_dirty_seq = seq;
+ dev->oldest_dirty_block = block_no;
+ }
+}
+
+void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev)
+{
+ if (!dev->param.is_yaffs2)
+ return;
+
+ if (!dev->oldest_dirty_seq)
+ yaffs_calc_oldest_dirty_seq(dev);
+}
+
+/*
+ * yaffs_clear_oldest_dirty_seq()
+ * Called when a block is erased or marked bad. (ie. when its seq_number
+ * becomes invalid). If the value matches the oldest then we clear
+ * dev->oldest_dirty_seq to force its recomputation.
+ */
+void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
+ struct yaffs_block_info *bi)
+{
+
+ if (!dev->param.is_yaffs2)
+ return;
+
+ if (!bi || bi->seq_number == dev->oldest_dirty_seq) {
+ dev->oldest_dirty_seq = 0;
+ dev->oldest_dirty_block = 0;
+ }
+}
+
+/*
+ * yaffs2_update_oldest_dirty_seq()
+ * Update the oldest dirty sequence number whenever we dirty a block.
+ * Only do this if the oldest_dirty_seq is actually being tracked.
+ */
+void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
+ struct yaffs_block_info *bi)
+{
+ if (!dev->param.is_yaffs2)
+ return;
+
+ if (dev->oldest_dirty_seq) {
+ if (dev->oldest_dirty_seq > bi->seq_number) {
+ dev->oldest_dirty_seq = bi->seq_number;
+ dev->oldest_dirty_block = block_no;
+ }
+ }
+}
+
+int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi)
+{
+
+ if (!dev->param.is_yaffs2)
+ return 1; /* disqualification only applies to yaffs2. */
+
+ if (!bi->has_shrink_hdr)
+ return 1; /* can gc */
+
+ yaffs2_find_oldest_dirty_seq(dev);
+
+ /* Can't do gc of this block if there are any blocks older than this
+ * one that have discarded pages.
+ */
+ return (bi->seq_number <= dev->oldest_dirty_seq);
+}
+
+/*
+ * yaffs2_find_refresh_block()
+ * periodically finds the oldest full block by sequence number for refreshing.
+ * Only for yaffs2.
+ */
+u32 yaffs2_find_refresh_block(struct yaffs_dev *dev)
+{
+ u32 b;
+ u32 oldest = 0;
+ u32 oldest_seq = 0;
+ struct yaffs_block_info *bi;
+
+ if (!dev->param.is_yaffs2)
+ return oldest;
+
+ /*
+ * If refresh period < 10 then refreshing is disabled.
+ */
+ if (dev->param.refresh_period < 10)
+ return oldest;
+
+ /*
+ * Fix broken values.
+ */
+ if (dev->refresh_skip > dev->param.refresh_period)
+ dev->refresh_skip = dev->param.refresh_period;
+
+ if (dev->refresh_skip > 0)
+ return oldest;
+
+ /*
+ * Refresh skip is now zero.
+ * We'll do a refresh this time around....
+ * Update the refresh skip and find the oldest block.
+ */
+ dev->refresh_skip = dev->param.refresh_period;
+ dev->refresh_count++;
+ bi = dev->block_info;
+ for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
+
+ if (bi->block_state == YAFFS_BLOCK_STATE_FULL) {
+
+ if (oldest < 1 || bi->seq_number < oldest_seq) {
+ oldest = b;
+ oldest_seq = bi->seq_number;
+ }
+ }
+ bi++;
+ }
+
+ if (oldest > 0) {
+ yaffs_trace(YAFFS_TRACE_GC,
+ "GC refresh count %d selected block %d with seq_number %d",
+ dev->refresh_count, oldest, oldest_seq);
+ }
+
+ return oldest;
+}
+
+int yaffs2_checkpt_required(struct yaffs_dev *dev)
+{
+ int nblocks;
+
+ if (!dev->param.is_yaffs2)
+ return 0;
+
+ nblocks = dev->internal_end_block - dev->internal_start_block + 1;
+
+ return !dev->param.skip_checkpt_wr &&
+ !dev->read_only && (nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
+}
+
+int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev)
+{
+ int retval;
+ int n_bytes = 0;
+ int n_blocks;
+ int dev_blocks;
+
+ if (!dev->param.is_yaffs2)
+ return 0;
+
+ if (!dev->checkpoint_blocks_required && yaffs2_checkpt_required(dev)) {
+ /* Not a valid value so recalculate */
+ dev_blocks = dev->param.end_block - dev->param.start_block + 1;
+ n_bytes += sizeof(struct yaffs_checkpt_validity);
+ n_bytes += sizeof(struct yaffs_checkpt_dev);
+ n_bytes += dev_blocks * sizeof(struct yaffs_block_info);
+ n_bytes += dev_blocks * dev->chunk_bit_stride;
+ n_bytes +=
+ (sizeof(struct yaffs_checkpt_obj) + sizeof(u32)) *
+ dev->n_obj;
+ n_bytes += (dev->tnode_size + sizeof(u32)) * dev->n_tnodes;
+ n_bytes += sizeof(struct yaffs_checkpt_validity);
+ n_bytes += sizeof(u32); /* checksum */
+
+ /* Round up and add 2 blocks to allow for some bad blocks,
+ * so add 3 */
+
+ n_blocks =
+ (n_bytes /
+ (dev->data_bytes_per_chunk *
+ dev->param.chunks_per_block)) + 3;
+
+ dev->checkpoint_blocks_required = n_blocks;
+ }
+
+ retval = dev->checkpoint_blocks_required - dev->blocks_in_checkpt;
+ if (retval < 0)
+ retval = 0;
+ return retval;
+}
+
+/*--------------------- Checkpointing --------------------*/
+
+static int yaffs2_wr_checkpt_validity_marker(struct yaffs_dev *dev, int head)
+{
+ struct yaffs_checkpt_validity cp;
+
+ memset(&cp, 0, sizeof(cp));
+
+ cp.struct_type = sizeof(cp);
+ cp.magic = YAFFS_MAGIC;
+ cp.version = YAFFS_CHECKPOINT_VERSION;
+ cp.head = (head) ? 1 : 0;
+
+ return (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp)) ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_validity_marker(struct yaffs_dev *dev, int head)
+{
+ struct yaffs_checkpt_validity cp;
+ int ok;
+
+ ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+
+ if (ok)
+ ok = (cp.struct_type == sizeof(cp)) &&
+ (cp.magic == YAFFS_MAGIC) &&
+ (cp.version == YAFFS_CHECKPOINT_VERSION) &&
+ (cp.head == ((head) ? 1 : 0));
+ return ok ? 1 : 0;
+}
+
+static void yaffs2_dev_to_checkpt_dev(struct yaffs_checkpt_dev *cp,
+ struct yaffs_dev *dev)
+{
+ cp->n_erased_blocks = dev->n_erased_blocks;
+ cp->alloc_block = dev->alloc_block;
+ cp->alloc_page = dev->alloc_page;
+ cp->n_free_chunks = dev->n_free_chunks;
+
+ cp->n_deleted_files = dev->n_deleted_files;
+ cp->n_unlinked_files = dev->n_unlinked_files;
+ cp->n_bg_deletions = dev->n_bg_deletions;
+ cp->seq_number = dev->seq_number;
+
+}
+
+static void yaffs_checkpt_dev_to_dev(struct yaffs_dev *dev,
+ struct yaffs_checkpt_dev *cp)
+{
+ dev->n_erased_blocks = cp->n_erased_blocks;
+ dev->alloc_block = cp->alloc_block;
+ dev->alloc_page = cp->alloc_page;
+ dev->n_free_chunks = cp->n_free_chunks;
+
+ dev->n_deleted_files = cp->n_deleted_files;
+ dev->n_unlinked_files = cp->n_unlinked_files;
+ dev->n_bg_deletions = cp->n_bg_deletions;
+ dev->seq_number = cp->seq_number;
+}
+
+static int yaffs2_wr_checkpt_dev(struct yaffs_dev *dev)
+{
+ struct yaffs_checkpt_dev cp;
+ u32 n_bytes;
+ u32 n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
+ int ok;
+
+ /* Write device runtime values */
+ yaffs2_dev_to_checkpt_dev(&cp, dev);
+ cp.struct_type = sizeof(cp);
+
+ ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
+ if (!ok)
+ return 0;
+
+ /* Write block info */
+ n_bytes = n_blocks * sizeof(struct yaffs_block_info);
+ ok = (yaffs2_checkpt_wr(dev, dev->block_info, n_bytes) == n_bytes);
+ if (!ok)
+ return 0;
+
+ /* Write chunk bits */
+ n_bytes = n_blocks * dev->chunk_bit_stride;
+ ok = (yaffs2_checkpt_wr(dev, dev->chunk_bits, n_bytes) == n_bytes);
+
+ return ok ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_dev(struct yaffs_dev *dev)
+{
+ struct yaffs_checkpt_dev cp;
+ u32 n_bytes;
+ u32 n_blocks =
+ (dev->internal_end_block - dev->internal_start_block + 1);
+ int ok;
+
+ ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+ if (!ok)
+ return 0;
+
+ if (cp.struct_type != sizeof(cp))
+ return 0;
+
+ yaffs_checkpt_dev_to_dev(dev, &cp);
+
+ n_bytes = n_blocks * sizeof(struct yaffs_block_info);
+
+ ok = (yaffs2_checkpt_rd(dev, dev->block_info, n_bytes) == n_bytes);
+
+ if (!ok)
+ return 0;
+
+ n_bytes = n_blocks * dev->chunk_bit_stride;
+
+ ok = (yaffs2_checkpt_rd(dev, dev->chunk_bits, n_bytes) == n_bytes);
+
+ return ok ? 1 : 0;
+}
+
+static void yaffs2_obj_checkpt_obj(struct yaffs_checkpt_obj *cp,
+ struct yaffs_obj *obj)
+{
+ cp->obj_id = obj->obj_id;
+ cp->parent_id = (obj->parent) ? obj->parent->obj_id : 0;
+ cp->hdr_chunk = obj->hdr_chunk;
+ cp->variant_type = obj->variant_type;
+ cp->deleted = obj->deleted;
+ cp->soft_del = obj->soft_del;
+ cp->unlinked = obj->unlinked;
+ cp->fake = obj->fake;
+ cp->rename_allowed = obj->rename_allowed;
+ cp->unlink_allowed = obj->unlink_allowed;
+ cp->serial = obj->serial;
+ cp->n_data_chunks = obj->n_data_chunks;
+
+ if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+ cp->size_or_equiv_obj = obj->variant.file_variant.file_size;
+ else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
+ cp->size_or_equiv_obj = obj->variant.hardlink_variant.equiv_id;
+}
+
+static int yaffs2_checkpt_obj_to_obj(struct yaffs_obj *obj,
+ struct yaffs_checkpt_obj *cp)
+{
+ struct yaffs_obj *parent;
+
+ if (obj->variant_type != cp->variant_type) {
+ yaffs_trace(YAFFS_TRACE_ERROR,
+ "Checkpoint read object %d type %d chunk %d does not match existing object type %d",
+ cp->obj_id, cp->variant_type, cp->hdr_chunk,
+ obj->variant_type);
+ return 0;
+ }
+
+ obj->obj_id = cp->obj_id;
+
+ if (cp->parent_id)
+ parent = yaffs_find_or_create_by_number(obj->my_dev,
+ cp->parent_id,
+ YAFFS_OBJECT_TYPE_DIRECTORY);
+ else
+ parent = NULL;
+
+ if (parent) {
+ if (parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+ yaffs_trace(YAFFS_TRACE_ALWAYS,
+ "Checkpoint read object %d parent %d type %d chunk %d Parent type, %d, not directory",
+ cp->obj_id, cp->parent_id,
+ cp->variant_type, cp->hdr_chunk,
+ parent->variant_type);
+ return 0;
+ }
+ yaffs_add_obj_to_dir(parent, obj);
+ }
+
+ obj->hdr_chunk = cp->hdr_chunk;
+ obj->variant_type = cp->variant_type;
+ obj->deleted = cp->deleted;
+ obj->soft_del = cp->soft_del;
+ obj->unlinked = cp->unlinked;
+ obj->fake = cp->fake;
+ obj->rename_allowed = cp->rename_allowed;
+ obj->unlink_allowed = cp->unlink_allowed;
+ obj->serial = cp->serial;
+ obj->n_data_chunks = cp->n_data_chunks;
+
+ if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+ obj->variant.file_variant.file_size = cp->size_or_equiv_obj;
+ else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
+ obj->variant.hardlink_variant.equiv_id = cp->size_or_equiv_obj;
+
+ if (obj->hdr_chunk > 0)
+ obj->lazy_loaded = 1;
+ return 1;
+}
+
+static int yaffs2_checkpt_tnode_worker(struct yaffs_obj *in,
+ struct yaffs_tnode *tn, u32 level,
+ int chunk_offset)
+{
+ int i;
+ struct yaffs_dev *dev = in->my_dev;
+ int ok = 1;
+ u32 base_offset;
+
+ if (!tn)
+ return 1;
+
+ if (level > 0) {
+ for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
+ if (!tn->internal[i])
+ continue;
+ ok = yaffs2_checkpt_tnode_worker(in,
+ tn->internal[i],
+ level - 1,
+ (chunk_offset <<
+ YAFFS_TNODES_INTERNAL_BITS) + i);
+ }
+ return ok;
+ }
+
+ /* Level 0 tnode */
+ base_offset = chunk_offset << YAFFS_TNODES_LEVEL0_BITS;
+ ok = (yaffs2_checkpt_wr(dev, &base_offset, sizeof(base_offset)) ==
+ sizeof(base_offset));
+ if (ok)
+ ok = (yaffs2_checkpt_wr(dev, tn, dev->tnode_size) ==
+ dev->tnode_size);
+
+ return ok;
+}
+
+static int yaffs2_wr_checkpt_tnodes(struct yaffs_obj *obj)
+{
+ u32 end_marker = ~0;
+ int ok = 1;
+
+ if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
+ return ok;
+
+ ok = yaffs2_checkpt_tnode_worker(obj,
+ obj->variant.file_variant.top,
+ obj->variant.file_variant.
+ top_level, 0);
+ if (ok)
+ ok = (yaffs2_checkpt_wr(obj->my_dev, &end_marker,
+ sizeof(end_marker)) == sizeof(end_marker));
+
+ return ok ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_tnodes(struct yaffs_obj *obj)
+{
+ u32 base_chunk;
+ int ok = 1;
+ struct yaffs_dev *dev = obj->my_dev;
+ struct yaffs_file_var *file_stuct_ptr = &obj->variant.file_variant;
+ struct yaffs_tnode *tn;
+ int nread = 0;
+
+ ok = (yaffs2_checkpt_rd(dev, &base_chunk, sizeof(base_chunk)) ==
+ sizeof(base_chunk));
+
+ while (ok && (~base_chunk)) {
+ nread++;
+ /* Read level 0 tnode */
+
+ tn = yaffs_get_tnode(dev);
+ if (tn)
+ ok = (yaffs2_checkpt_rd(dev, tn, dev->tnode_size) ==
+ dev->tnode_size);
+ else
+ ok = 0;
+
+ if (tn && ok)
+ ok = yaffs_add_find_tnode_0(dev,
+ file_stuct_ptr,
+ base_chunk, tn) ? 1 : 0;
+
+ if (ok)
+ ok = (yaffs2_checkpt_rd
+ (dev, &base_chunk,
+ sizeof(base_chunk)) == sizeof(base_chunk));
+ }
+
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "Checkpoint read tnodes %d records, last %d. ok %d",
+ nread, base_chunk, ok);
+
+ return ok ? 1 : 0;
+}
+
+static int yaffs2_wr_checkpt_objs(struct yaffs_dev *dev)
+{
+ struct yaffs_obj *obj;
+ struct yaffs_checkpt_obj cp;
+ int i;
+ int ok = 1;
+ struct list_head *lh;
+
+ /* Iterate through the objects in each hash entry,
+ * dumping them to the checkpointing stream.
+ */
+
+ for (i = 0; ok && i < YAFFS_NOBJECT_BUCKETS; i++) {
+ list_for_each(lh, &dev->obj_bucket[i].list) {
+ obj = list_entry(lh, struct yaffs_obj, hash_link);
+ if (!obj->defered_free) {
+ yaffs2_obj_checkpt_obj(&cp, obj);
+ cp.struct_type = sizeof(cp);
+
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "Checkpoint write object %d parent %d type %d chunk %d obj addr %p",
+ cp.obj_id, cp.parent_id,
+ cp.variant_type, cp.hdr_chunk, obj);
+
+ ok = (yaffs2_checkpt_wr(dev, &cp,
+ sizeof(cp)) == sizeof(cp));
+
+ if (ok &&
+ obj->variant_type ==
+ YAFFS_OBJECT_TYPE_FILE)
+ ok = yaffs2_wr_checkpt_tnodes(obj);
+ }
+ }
+ }
+
+ /* Dump end of list */
+ memset(&cp, 0xff, sizeof(struct yaffs_checkpt_obj));
+ cp.struct_type = sizeof(cp);
+
+ if (ok)
+ ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
+
+ return ok ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_objs(struct yaffs_dev *dev)
+{
+ struct yaffs_obj *obj;
+ struct yaffs_checkpt_obj cp;
+ int ok = 1;
+ int done = 0;
+ LIST_HEAD(hard_list);
+
+
+ while (ok && !done) {
+ ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+ if (cp.struct_type != sizeof(cp)) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "struct size %d instead of %d ok %d",
+ cp.struct_type, (int)sizeof(cp), ok);
+ ok = 0;
+ }
+
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "Checkpoint read object %d parent %d type %d chunk %d ",
+ cp.obj_id, cp.parent_id, cp.variant_type,
+ cp.hdr_chunk);
+
+ if (ok && cp.obj_id == ~0) {
+ done = 1;
+ } else if (ok) {
+ obj =
+ yaffs_find_or_create_by_number(dev, cp.obj_id,
+ cp.variant_type);
+ if (obj) {
+ ok = yaffs2_checkpt_obj_to_obj(obj, &cp);
+ if (!ok)
+ break;
+ if (obj->variant_type ==
+ YAFFS_OBJECT_TYPE_FILE) {
+ ok = yaffs2_rd_checkpt_tnodes(obj);
+ } else if (obj->variant_type ==
+ YAFFS_OBJECT_TYPE_HARDLINK) {
+ list_add(&obj->hard_links, &hard_list);
+ }
+ } else {
+ ok = 0;
+ }
+ }
+ }
+
+ if (ok)
+ yaffs_link_fixup(dev, &hard_list);
+
+ return ok ? 1 : 0;
+}
+
+static int yaffs2_wr_checkpt_sum(struct yaffs_dev *dev)
+{
+ u32 checkpt_sum;
+ int ok;
+
+ yaffs2_get_checkpt_sum(dev, &checkpt_sum);
+
+ ok = (yaffs2_checkpt_wr(dev, &checkpt_sum, sizeof(checkpt_sum)) ==
+ sizeof(checkpt_sum));
+
+ if (!ok)
+ return 0;
+
+ return 1;
+}
+
+static int yaffs2_rd_checkpt_sum(struct yaffs_dev *dev)
+{
+ u32 checkpt_sum0;
+ u32 checkpt_sum1;
+ int ok;
+
+ yaffs2_get_checkpt_sum(dev, &checkpt_sum0);
+
+ ok = (yaffs2_checkpt_rd(dev, &checkpt_sum1, sizeof(checkpt_sum1)) ==
+ sizeof(checkpt_sum1));
+
+ if (!ok)
+ return 0;
+
+ if (checkpt_sum0 != checkpt_sum1)
+ return 0;
+
+ return 1;
+}
+
+static int yaffs2_wr_checkpt_data(struct yaffs_dev *dev)
+{
+ int ok = 1;
+
+ if (!yaffs2_checkpt_required(dev)) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "skipping checkpoint write");
+ ok = 0;
+ }
+
+ if (ok)
+ ok = yaffs2_checkpt_open(dev, 1);
+
+ if (ok) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "write checkpoint validity");
+ ok = yaffs2_wr_checkpt_validity_marker(dev, 1);
+ }
+ if (ok) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "write checkpoint device");
+ ok = yaffs2_wr_checkpt_dev(dev);
+ }
+ if (ok) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "write checkpoint objects");
+ ok = yaffs2_wr_checkpt_objs(dev);
+ }
+ if (ok) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "write checkpoint validity");
+ ok = yaffs2_wr_checkpt_validity_marker(dev, 0);
+ }
+
+ if (ok)
+ ok = yaffs2_wr_checkpt_sum(dev);
+
+ if (!yaffs_checkpt_close(dev))
+ ok = 0;
+
+ if (ok)
+ dev->is_checkpointed = 1;
+ else
+ dev->is_checkpointed = 0;
+
+ return dev->is_checkpointed;
+}
+
+static int yaffs2_rd_checkpt_data(struct yaffs_dev *dev)
+{
+ int ok = 1;
+
+ if (!dev->param.is_yaffs2)
+ ok = 0;
+
+ if (ok && dev->param.skip_checkpt_rd) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "skipping checkpoint read");
+ ok = 0;
+ }
+
+ if (ok)
+ ok = yaffs2_checkpt_open(dev, 0); /* open for read */
+
+ if (ok) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "read checkpoint validity");
+ ok = yaffs2_rd_checkpt_validity_marker(dev, 1);
+ }
+ if (ok) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "read checkpoint device");
+ ok = yaffs2_rd_checkpt_dev(dev);
+ }
+ if (ok) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "read checkpoint objects");
+ ok = yaffs2_rd_checkpt_objs(dev);
+ }
+ if (ok) {
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "read checkpoint validity");
+ ok = yaffs2_rd_checkpt_validity_marker(dev, 0);
+ }
+
+ if (ok) {
+ ok = yaffs2_rd_checkpt_sum(dev);
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "read checkpoint checksum %d", ok);
+ }
+
+ if (!yaffs_checkpt_close(dev))
+ ok = 0;
+
+ if (ok)
+ dev->is_checkpointed = 1;
+ else
+ dev->is_checkpointed = 0;
+
+ return ok ? 1 : 0;
+}
+
+void yaffs2_checkpt_invalidate(struct yaffs_dev *dev)
+{
+ if (dev->is_checkpointed || dev->blocks_in_checkpt > 0) {
+ dev->is_checkpointed = 0;
+ yaffs2_checkpt_invalidate_stream(dev);
+ }
+ if (dev->param.sb_dirty_fn)
+ dev->param.sb_dirty_fn(dev);
+}
+
+int yaffs_checkpoint_save(struct yaffs_dev *dev)
+{
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "save entry: is_checkpointed %d",
+ dev->is_checkpointed);
+
+ yaffs_verify_objects(dev);
+ yaffs_verify_blocks(dev);
+ yaffs_verify_free_chunks(dev);
+
+ if (!dev->is_checkpointed) {
+ yaffs2_checkpt_invalidate(dev);
+ yaffs2_wr_checkpt_data(dev);
+ }
+
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
+ "save exit: is_checkpointed %d",
+ dev->is_checkpointed);
+
+ return dev->is_checkpointed;
+}
+
+int yaffs2_checkpt_restore(struct yaffs_dev *dev)
+{
+ int retval;
+
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "restore entry: is_checkpointed %d",
+ dev->is_checkpointed);
+
+ retval = yaffs2_rd_checkpt_data(dev);
+
+ if (dev->is_checkpointed) {
+ yaffs_verify_objects(dev);
+ yaffs_verify_blocks(dev);
+ yaffs_verify_free_chunks(dev);
+ }
+
+ yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+ "restore exit: is_checkpointed %d",
+ dev->is_checkpointed);
+
+ return retval;
+}
+
+int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size)
+{
+ /* if new_size > old_file_size.
+ * We're going to be writing a hole.
+ * If the hole is small then write zeros otherwise write a start
+ * of hole marker.
+ */
+ loff_t old_file_size;
+ loff_t increase;
+ int small_hole;
+ int result = YAFFS_OK;
+ struct yaffs_dev *dev = NULL;
+ u8 *local_buffer = NULL;
+ int small_increase_ok = 0;
+
+ if (!obj)
+ return YAFFS_FAIL;
+
+ if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
+ return YAFFS_FAIL;
+
+ dev = obj->my_dev;
+
+ /* Bail out if not yaffs2 mode */
+ if (!dev->param.is_yaffs2)
+ return YAFFS_OK;
+
+ old_file_size = obj->variant.file_variant.file_size;
+
+ if (new_size <= old_file_size)
+ return YAFFS_OK;
+
+ increase = new_size - old_file_size;
+
+ if (increase < YAFFS_SMALL_HOLE_THRESHOLD * dev->data_bytes_per_chunk &&
+ yaffs_check_alloc_available(dev, YAFFS_SMALL_HOLE_THRESHOLD + 1))
+ small_hole = 1;
+ else
+ small_hole = 0;
+
+ if (small_hole)
+ local_buffer = yaffs_get_temp_buffer(dev);
+
+ if (local_buffer) {
+ /* fill hole with zero bytes */
+ loff_t pos = old_file_size;
+ int this_write;
+ int written;
+ memset(local_buffer, 0, dev->data_bytes_per_chunk);
+ small_increase_ok = 1;
+
+ while (increase > 0 && small_increase_ok) {
+ this_write = increase;
+ if (this_write > dev->data_bytes_per_chunk)
+ this_write = dev->data_bytes_per_chunk;
+ written =
+ yaffs_do_file_wr(obj, local_buffer, pos, this_write,
+ 0);
+ if (written == this_write) {
+ pos += this_write;
+ increase -= this_write;
+ } else {
+ small_increase_ok = 0;
+ }
+ }
+
+ yaffs_release_temp_buffer(dev, local_buffer);
+
+ /* If out of space then reverse any chunks we've added */
+ if (!small_increase_ok)
+ yaffs_resize_file_down(obj, old_file_size);
+ }
+
+ if (!small_increase_ok &&
+ obj->parent &&
+ obj->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
+ obj->parent->obj_id != YAFFS_OBJECTID_DELETED) {
+ /* Write a hole start header with the old file size */
+ yaffs_update_oh(obj, NULL, 0, 1, 0, NULL);
+ }
+
+ return result;
+}
+
+struct yaffs_block_index {
+ int seq;
+ int block;
+};
+
+static int yaffs2_ybicmp(const void *a, const void *b)
+{
+ int aseq = ((struct yaffs_block_index *)a)->seq;
+ int bseq = ((struct yaffs_block_index *)b)->seq;
+ int ablock = ((struct yaffs_block_index *)a)->block;
+ int bblock = ((struct yaffs_block_index *)b)->block;
+
+ if (aseq == bseq)
+ return ablock - bblock;
+
+ return aseq - bseq;
+}
+
+static inline int yaffs2_scan_chunk(struct yaffs_dev *dev,
+ struct yaffs_block_info *bi,
+ int blk, int chunk_in_block,
+ int *found_chunks,
+ u8 *chunk_data,
+ struct list_head *hard_list,
+ int summary_available)
+{
+ struct yaffs_obj_hdr *oh;
+ struct yaffs_obj *in;
+ struct yaffs_obj *parent;
+ int equiv_id;
+ loff_t file_size;
+ int is_shrink;
+ int is_unlinked;
+ struct yaffs_ext_tags tags;
+ int result;
+ int alloc_failed = 0;
+ int chunk = blk * dev->param.chunks_per_block + chunk_in_block;
+ struct yaffs_file_var *file_var;
+ struct yaffs_hardlink_var *hl_var;
+ struct yaffs_symlink_var *sl_var;
+
+ if (summary_available) {
+ result = yaffs_summary_fetch(dev, &tags, chunk_in_block);
+ tags.seq_number = bi->seq_number;
+ }
+
+ if (!summary_available || tags.obj_id == 0) {
+ result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL, &tags);
+ dev->tags_used++;
+ } else {
+ dev->summary_used++;
+ }
+
+ /* Let's have a good look at this chunk... */
+
+ if (!tags.chunk_used) {
+ /* An unassigned chunk in the block.
+ * If there are used chunks after this one, then
+ * it is a chunk that was skipped due to failing
+ * the erased check. Just skip it so that it can
+ * be deleted.
+ * But, more typically, We get here when this is
+ * an unallocated chunk and his means that
+ * either the block is empty or this is the one
+ * being allocated from
+ */
+
+ if (*found_chunks) {
+ /* This is a chunk that was skipped due
+ * to failing the erased check */
+ } else if (chunk_in_block == 0) {
+ /* We're looking at the first chunk in
+ * the block so the block is unused */
+ bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
+ dev->n_erased_blocks++;
+ } else {
+ if (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
+ bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
+ if (dev->seq_number == bi->seq_number) {
+ /* Allocating from this block*/
+ yaffs_trace(YAFFS_TRACE_SCAN,
+ " Allocating from %d %d",
+ blk, chunk_in_block);
+
+ bi->block_state =
+ YAFFS_BLOCK_STATE_ALLOCATING;
+ dev->alloc_block = blk;
+ dev->alloc_page = chunk_in_block;
+ dev->alloc_block_finder = blk;
+ } else {
+ /* This is a partially written block
+ * that is not the current
+ * allocation block.
+ */
+ yaffs_trace(YAFFS_TRACE_SCAN,
+ "Partially written block %d detected. gc will fix this.",
+ blk);
+ }
+ }
+ }
+
+ dev->n_free_chunks++;
+
+ } else if (tags.ecc_result ==
+ YAFFS_ECC_RESULT_UNFIXED) {
+ yaffs_trace(YAFFS_TRACE_SCAN,
+ " Unfixed ECC in chunk(%d:%d), chunk ignored",
+ blk, chunk_in_block);
+ dev->n_free_chunks++;
+ } else if (tags.obj_id > YAFFS_MAX_OBJECT_ID ||
+ tags.chunk_id > YAFFS_MAX_CHUNK_ID ||
+ tags.obj_id == YAFFS_OBJECTID_SUMMARY ||
+ (tags.chunk_id > 0 &&
+ tags.n_bytes > dev->data_bytes_per_chunk) ||
+ tags.seq_number != bi->seq_number) {
+ yaffs_trace(YAFFS_TRACE_SCAN,
+ "Chunk (%d:%d) with bad tags:obj = %d, chunk_id = %d, n_bytes = %d, ignored",
+ blk, chunk_in_block, tags.obj_id,
+ tags.chunk_id, tags.n_bytes);
+ dev->n_free_chunks++;
+ } else if (tags.chunk_id > 0) {
+ /* chunk_id > 0 so it is a data chunk... */
+ loff_t endpos;
+ loff_t chunk_base = (tags.chunk_id - 1) *
+ dev->data_bytes_per_chunk;
+
+ *found_chunks = 1;
+
+ yaffs_set_chunk_bit(dev, blk, chunk_in_block);
+ bi->pages_in_use++;
+
+ in = yaffs_find_or_create_by_number(dev,
+ tags.obj_id,
+ YAFFS_OBJECT_TYPE_FILE);
+ if (!in)
+ /* Out of memory */
+ alloc_failed = 1;
+
+ if (in &&
+ in->variant_type == YAFFS_OBJECT_TYPE_FILE &&
+ chunk_base < in->variant.file_variant.shrink_size) {
+ /* This has not been invalidated by
+ * a resize */
+ if (!yaffs_put_chunk_in_file(in, tags.chunk_id,
+ chunk, -1))
+ alloc_failed = 1;
+
+ /* File size is calculated by looking at
+ * the data chunks if we have not
+ * seen an object header yet.
+ * Stop this practice once we find an
+ * object header.
+ */
+ endpos = chunk_base + tags.n_bytes;
+
+ if (!in->valid &&
+ in->variant.file_variant.scanned_size < endpos) {
+ in->variant.file_variant.
+ scanned_size = endpos;
+ in->variant.file_variant.
+ file_size = endpos;
+ }
+ } else if (in) {
+ /* This chunk has been invalidated by a
+ * resize, or a past file deletion
+ * so delete the chunk*/
+ yaffs_chunk_del(dev, chunk, 1, __LINE__);
+ }
+ } else {
+ /* chunk_id == 0, so it is an ObjectHeader.
+ * Thus, we read in the object header and make
+ * the object
+ */
+ *found_chunks = 1;
+
+ yaffs_set_chunk_bit(dev, blk, chunk_in_block);
+ bi->pages_in_use++;
+
+ oh = NULL;
+ in = NULL;
+
+ if (tags.extra_available) {
+ in = yaffs_find_or_create_by_number(dev,
+ tags.obj_id,
+ tags.extra_obj_type);
+ if (!in)
+ alloc_failed = 1;
+ }
+
+ if (!in ||
+ (!in->valid && dev->param.disable_lazy_load) ||
+ tags.extra_shadows ||
+ (!in->valid && (tags.obj_id == YAFFS_OBJECTID_ROOT ||
+ tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND))) {
+
+ /* If we don't have valid info then we
+ * need to read the chunk
+ * TODO In future we can probably defer
+ * reading the chunk and living with
+ * invalid data until needed.
+ */
+
+ result = yaffs_rd_chunk_tags_nand(dev,
+ chunk,
+ chunk_data,
+ NULL);
+
+ oh = (struct yaffs_obj_hdr *)chunk_data;
+
+ if (dev->param.inband_tags) {
+ /* Fix up the header if they got
+ * corrupted by inband tags */
+ oh->shadows_obj =
+ oh->inband_shadowed_obj_id;
+ oh->is_shrink =
+ oh->inband_is_shrink;
+ }
+
+ if (!in) {
+ in = yaffs_find_or_create_by_number(dev,
+ tags.obj_id, oh->type);
+ if (!in)
+ alloc_failed = 1;
+ }
+ }
+
+ if (!in) {
+ /* TODO Hoosterman we have a problem! */
+ yaffs_trace(YAFFS_TRACE_ERROR,
+ "yaffs tragedy: Could not make object for object %d at chunk %d during scan",
+ tags.obj_id, chunk);
+ return YAFFS_FAIL;
+ }
+
+ if (in->valid) {
+ /* We have already filled this one.
+ * We have a duplicate that will be
+ * discarded, but we first have to suck
+ * out resize info if it is a file.
+ */
+ if ((in->variant_type == YAFFS_OBJECT_TYPE_FILE) &&
+ ((oh && oh->type == YAFFS_OBJECT_TYPE_FILE) ||
+ (tags.extra_available &&
+ tags.extra_obj_type == YAFFS_OBJECT_TYPE_FILE)
+ )) {
+ loff_t this_size = (oh) ?
+ yaffs_oh_to_size(oh) :
+ tags.extra_file_size;
+ u32 parent_obj_id = (oh) ?
+ oh->parent_obj_id :
+ tags.extra_parent_id;
+
+ is_shrink = (oh) ?
+ oh->is_shrink :
+ tags.extra_is_shrink;
+
+ /* If it is deleted (unlinked
+ * at start also means deleted)
+ * we treat the file size as
+ * being zeroed at this point.
+ */
+ if (parent_obj_id == YAFFS_OBJECTID_DELETED ||
+ parent_obj_id == YAFFS_OBJECTID_UNLINKED) {
+ this_size = 0;
+ is_shrink = 1;
+ }
+
+ if (is_shrink &&
+ in->variant.file_variant.shrink_size >
+ this_size)
+ in->variant.file_variant.shrink_size =
+ this_size;
+
+ if (is_shrink)
+ bi->has_shrink_hdr = 1;
+ }
+ /* Use existing - destroy this one. */
+ yaffs_chunk_del(dev, chunk, 1, __LINE__);
+ }
+
+ if (!in->valid && in->variant_type !=
+ (oh ? oh->type : tags.extra_obj_type))
+ yaffs_trace(YAFFS_TRACE_ERROR,
+ "yaffs tragedy: Bad object type, %d != %d, for object %d at chunk %d during scan",
+ oh ? oh->type : tags.extra_obj_type,
+ in->variant_type, tags.obj_id,
+ chunk);
+
+ if (!in->valid &&
+ (tags.obj_id == YAFFS_OBJECTID_ROOT ||
+ tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND)) {
+ /* We only load some info, don't fiddle
+ * with directory structure */
+ in->valid = 1;
+
+ if (oh) {
+ in->yst_mode = oh->yst_mode;
+ yaffs_load_attribs(in, oh);
+ in->lazy_loaded = 0;
+ } else {
+ in->lazy_loaded = 1;
+ }
+ in->hdr_chunk = chunk;
+
+ } else if (!in->valid) {
+ /* we need to load this info */
+ in->valid = 1;
+ in->hdr_chunk = chunk;
+ if (oh) {
+ in->variant_type = oh->type;
+ in->yst_mode = oh->yst_mode;
+ yaffs_load_attribs(in, oh);
+
+ if (oh->shadows_obj > 0)
+ yaffs_handle_shadowed_obj(dev,
+ oh->shadows_obj, 1);
+
+ yaffs_set_obj_name_from_oh(in, oh);
+ parent = yaffs_find_or_create_by_number(dev,
+ oh->parent_obj_id,
+ YAFFS_OBJECT_TYPE_DIRECTORY);
+ file_size = yaffs_oh_to_size(oh);
+ is_shrink = oh->is_shrink;
+ equiv_id = oh->equiv_id;
+ } else {
+ in->variant_type = tags.extra_obj_type;
+ parent = yaffs_find_or_create_by_number(dev,
+ tags.extra_parent_id,
+ YAFFS_OBJECT_TYPE_DIRECTORY);
+ file_size = tags.extra_file_size;
+ is_shrink = tags.extra_is_shrink;
+ equiv_id = tags.extra_equiv_id;
+ in->lazy_loaded = 1;
+ }
+ in->dirty = 0;
+
+ if (!parent)
+ alloc_failed = 1;
+
+ /* directory stuff...
+ * hook up to parent
+ */
+
+ if (parent &&
+ parent->variant_type == YAFFS_OBJECT_TYPE_UNKNOWN) {
+ /* Set up as a directory */
+ parent->variant_type =
+ YAFFS_OBJECT_TYPE_DIRECTORY;
+ INIT_LIST_HEAD(&parent->
+ variant.dir_variant.children);
+ } else if (!parent ||
+ parent->variant_type !=
+ YAFFS_OBJECT_TYPE_DIRECTORY) {
+ /* Hoosterman, another problem....
+ * Trying to use a non-directory as a directory
+ */
+
+ yaffs_trace(YAFFS_TRACE_ERROR,
+ "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
+ );
+ parent = dev->lost_n_found;
+ }
+ yaffs_add_obj_to_dir(parent, in);
+
+ is_unlinked = (parent == dev->del_dir) ||
+ (parent == dev->unlinked_dir);
+
+ if (is_shrink)
+ /* Mark the block */
+ bi->has_shrink_hdr = 1;
+
+ /* Note re hardlinks.
+ * Since we might scan a hardlink before its equivalent
+ * object is scanned we put them all in a list.
+ * After scanning is complete, we should have all the
+ * objects, so we run through this list and fix up all
+ * the chains.
+ */
+
+ switch (in->variant_type) {
+ case YAFFS_OBJECT_TYPE_UNKNOWN:
+ /* Todo got a problem */
+ break;
+ case YAFFS_OBJECT_TYPE_FILE:
+ file_var = &in->variant.file_variant;
+ if (file_var->scanned_size < file_size) {
+ /* This covers the case where the file
+ * size is greater than the data held.
+ * This will happen if the file is
+ * resized to be larger than its
+ * current data extents.
+ */
+ file_var->file_size = file_size;
+ file_var->scanned_size = file_size;
+ }
+
+ if (file_var->shrink_size > file_size)
+ file_var->shrink_size = file_size;
+
+ break;
+ case YAFFS_OBJECT_TYPE_HARDLINK:
+ hl_var = &in->variant.hardlink_variant;
+ if (!is_unlinked) {
+ hl_var->equiv_id = equiv_id;
+ list_add(&in->hard_links, hard_list);
+ }
+ break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY:
+ /* Do nothing */
+ break;
+ case YAFFS_OBJECT_TYPE_SPECIAL:
+ /* Do nothing */
+ break;
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ sl_var = &in->variant.symlink_variant;
+ if (oh) {
+ sl_var->alias =
+ yaffs_clone_str(oh->alias);
+ if (!sl_var->alias)
+ alloc_failed = 1;
+ }
+ break;
+ }
+ }
+ }
+ return alloc_failed ? YAFFS_FAIL : YAFFS_OK;
+}
+
+int yaffs2_scan_backwards(struct yaffs_dev *dev)
+{
+ int blk;
+ int block_iter;
+ int start_iter;
+ int end_iter;
+ int n_to_scan = 0;
+ enum yaffs_block_state state;
+ int c;
+ int deleted;
+ LIST_HEAD(hard_list);
+ struct yaffs_block_info *bi;
+ u32 seq_number;
+ int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
+ u8 *chunk_data;
+ int found_chunks;
+ int alloc_failed = 0;
+ struct yaffs_block_index *block_index = NULL;
+ int alt_block_index = 0;
+ int summary_available;
+
+ yaffs_trace(YAFFS_TRACE_SCAN,
+ "yaffs2_scan_backwards starts intstartblk %d intendblk %d...",
+ dev->internal_start_block, dev->internal_end_block);
+
+ dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
+
+ block_index =
+ kmalloc(n_blocks * sizeof(struct yaffs_block_index), GFP_NOFS);
+
+ if (!block_index) {
+ block_index =
+ vmalloc(n_blocks * sizeof(struct yaffs_block_index));
+ alt_block_index = 1;
+ }
+
+ if (!block_index) {
+ yaffs_trace(YAFFS_TRACE_SCAN,
+ "yaffs2_scan_backwards() could not allocate block index!"
+ );
+ return YAFFS_FAIL;
+ }
+
+ dev->blocks_in_checkpt = 0;
+
+ chunk_data = yaffs_get_temp_buffer(dev);
+
+ /* Scan all the blocks to determine their state */
+ bi = dev->block_info;
+ for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
+ blk++) {
+ yaffs_clear_chunk_bits(dev, blk);
+ bi->pages_in_use = 0;
+ bi->soft_del_pages = 0;
+
+ yaffs_query_init_block_state(dev, blk, &state, &seq_number);
+
+ bi->block_state = state;
+ bi->seq_number = seq_number;
+
+ if (bi->seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA)
+ bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
+ if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
+ bi->block_state = YAFFS_BLOCK_STATE_DEAD;
+
+ yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
+ "Block scanning block %d state %d seq %d",
+ blk, bi->block_state, seq_number);
+
+ if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
+ dev->blocks_in_checkpt++;
+
+ } else if (bi->block_state == YAFFS_BLOCK_STATE_DEAD) {
+ yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+ "block %d is bad", blk);
+ } else if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
+ yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
+ dev->n_erased_blocks++;
+ dev->n_free_chunks += dev->param.chunks_per_block;
+ } else if (bi->block_state ==
+ YAFFS_BLOCK_STATE_NEEDS_SCAN) {
+ /* Determine the highest sequence number */
+ if (seq_number >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
+ seq_number < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
+ block_index[n_to_scan].seq = seq_number;
+ block_index[n_to_scan].block = blk;
+ n_to_scan++;
+ if (seq_number >= dev->seq_number)
+ dev->seq_number = seq_number;
+ } else {
+ /* TODO: Nasty sequence number! */
+ yaffs_trace(YAFFS_TRACE_SCAN,
+ "Block scanning block %d has bad sequence number %d",
+ blk, seq_number);
+ }
+ }
+ bi++;
+ }
+
+ yaffs_trace(YAFFS_TRACE_SCAN, "%d blocks to be sorted...", n_to_scan);
+
+ cond_resched();
+
+ /* Sort the blocks by sequence number */
+ sort(block_index, n_to_scan, sizeof(struct yaffs_block_index),
+ yaffs2_ybicmp, NULL);
+
+ cond_resched();
+
+ yaffs_trace(YAFFS_TRACE_SCAN, "...done");
+
+ /* Now scan the blocks looking at the data. */
+ start_iter = 0;
+ end_iter = n_to_scan - 1;
+ yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "%d blocks to scan", n_to_scan);
+
+ /* For each block.... backwards */
+ for (block_iter = end_iter;
+ !alloc_failed && block_iter >= start_iter;
+ block_iter--) {
+ /* Cooperative multitasking! This loop can run for so
+ long that watchdog timers expire. */
+ cond_resched();
+
+ /* get the block to scan in the correct order */
+ blk = block_index[block_iter].block;
+ bi = yaffs_get_block_info(dev, blk);
+ deleted = 0;
+
+ summary_available = yaffs_summary_read(dev, dev->sum_tags, blk);
+
+ /* For each chunk in each block that needs scanning.... */
+ found_chunks = 0;
+ if (summary_available)
+ c = dev->chunks_per_summary - 1;
+ else
+ c = dev->param.chunks_per_block - 1;
+
+ for (/* c is already initialised */;
+ !alloc_failed && c >= 0 &&
+ (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
+ bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING);
+ c--) {
+ /* Scan backwards...
+ * Read the tags and decide what to do
+ */
+ if (yaffs2_scan_chunk(dev, bi, blk, c,
+ &found_chunks, chunk_data,
+ &hard_list, summary_available) ==
+ YAFFS_FAIL)
+ alloc_failed = 1;
+ }
+
+ if (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
+ /* If we got this far while scanning, then the block
+ * is fully allocated. */
+ bi->block_state = YAFFS_BLOCK_STATE_FULL;
+ }
+
+ /* Now let's see if it was dirty */
+ if (bi->pages_in_use == 0 &&
+ !bi->has_shrink_hdr &&
+ bi->block_state == YAFFS_BLOCK_STATE_FULL) {
+ yaffs_block_became_dirty(dev, blk);
+ }
+ }
+
+ yaffs_skip_rest_of_block(dev);
+
+ if (alt_block_index)
+ vfree(block_index);
+ else
+ kfree(block_index);
+
+ /* Ok, we've done all the scanning.
+ * Fix up the hard link chains.
+ * We have scanned all the objects, now it's time to add these
+ * hardlinks.
+ */
+ yaffs_link_fixup(dev, &hard_list);
+
+ yaffs_release_temp_buffer(dev, chunk_data);
+
+ if (alloc_failed)
+ return YAFFS_FAIL;
+
+ yaffs_trace(YAFFS_TRACE_SCAN, "yaffs2_scan_backwards ends");
+
+ return YAFFS_OK;
+}