2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
4 * Copyright (C) 2002-2011 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
7 * Created by Charles Manning <charles@aleph1.co.uk>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include "yaffs_yaffs1.h"
16 #include "yaffs_trace.h"
17 #include "yaffs_bitmap.h"
18 #include "yaffs_getblockinfo.h"
19 #include "yaffs_nand.h"
20 #include "yaffs_attribs.h"
22 int yaffs1_scan(struct yaffs_dev *dev)
24 struct yaffs_ext_tags tags;
29 enum yaffs_block_state state;
31 struct yaffs_block_info *bi;
33 struct yaffs_obj_hdr *oh;
35 struct yaffs_obj *parent;
37 struct yaffs_shadow_fixer *shadow_fixers = NULL;
40 yaffs_trace(YAFFS_TRACE_SCAN,
41 "yaffs1_scan starts intstartblk %d intendblk %d...",
42 dev->internal_start_block, dev->internal_end_block);
44 chunk_data = yaffs_get_temp_buffer(dev);
46 dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
48 /* Scan all the blocks to determine their state */
50 for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
52 yaffs_clear_chunk_bits(dev, blk);
54 bi->soft_del_pages = 0;
56 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
58 bi->block_state = state;
59 bi->seq_number = seq_number;
61 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
62 bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
64 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
65 "Block scanning block %d state %d seq %d",
66 blk, state, seq_number);
68 if (state == YAFFS_BLOCK_STATE_DEAD) {
69 yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
70 "block %d is bad", blk);
71 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
72 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
73 dev->n_erased_blocks++;
74 dev->n_free_chunks += dev->param.chunks_per_block;
79 /* For each block.... */
80 for (blk = dev->internal_start_block;
81 !alloc_failed && blk <= dev->internal_end_block; blk++) {
85 bi = yaffs_get_block_info(dev, blk);
86 state = bi->block_state;
90 /* For each chunk in each block that needs scanning.... */
92 !alloc_failed && c < dev->param.chunks_per_block &&
93 state == YAFFS_BLOCK_STATE_NEEDS_SCAN; c++) {
94 /* Read the tags and decide what to do */
95 chunk = blk * dev->param.chunks_per_block + c;
97 yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
100 /* Let's have a good look at this chunk... */
102 if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED ||
108 dev->n_free_chunks++;
109 } else if (!tags.chunk_used) {
110 /* An unassigned chunk in the block
111 * This means that either the block is empty or
112 * this is the one being allocated from
116 /* We're looking at the first chunk in
117 *the block so the block is unused */
118 state = YAFFS_BLOCK_STATE_EMPTY;
119 dev->n_erased_blocks++;
121 /* this is the block being allocated */
122 yaffs_trace(YAFFS_TRACE_SCAN,
123 " Allocating from %d %d",
125 state = YAFFS_BLOCK_STATE_ALLOCATING;
126 dev->alloc_block = blk;
128 dev->alloc_block_finder = blk;
132 dev->n_free_chunks +=
133 (dev->param.chunks_per_block - c);
134 } else if (tags.chunk_id > 0) {
135 /* chunk_id > 0 so it is a data chunk... */
138 yaffs_set_chunk_bit(dev, blk, c);
141 in = yaffs_find_or_create_by_number(dev,
143 YAFFS_OBJECT_TYPE_FILE);
144 /* PutChunkIntoFile checks for a clash
145 * (two data chunks with the same chunk_id).
152 if (!yaffs_put_chunk_in_file
153 (in, tags.chunk_id, chunk, 1))
158 (tags.chunk_id - 1) *
159 dev->data_bytes_per_chunk +
163 YAFFS_OBJECT_TYPE_FILE &&
164 in->variant.file_variant.scanned_size <
166 in->variant.file_variant.scanned_size =
168 if (!dev->param.use_header_file_size) {
170 file_variant.file_size =
172 file_variant.scanned_size;
177 /* chunk_id == 0, so it is an ObjectHeader.
180 yaffs_set_chunk_bit(dev, blk, c);
183 yaffs_rd_chunk_tags_nand(dev, chunk,
187 oh = (struct yaffs_obj_hdr *)chunk_data;
189 in = yaffs_find_by_number(dev, tags.obj_id);
190 if (in && in->variant_type != oh->type) {
191 /* This should not happen, but somehow
192 * Wev'e ended up with an obj_id that
193 * has been reused but not yet deleted,
194 * and worse still it has changed type.
195 * Delete the old object.
202 in = yaffs_find_or_create_by_number(dev,
209 if (in && oh->shadows_obj > 0) {
211 struct yaffs_shadow_fixer *fixer;
214 (struct yaffs_shadow_fixer),
217 fixer->next = shadow_fixers;
218 shadow_fixers = fixer;
219 fixer->obj_id = tags.obj_id;
222 yaffs_trace(YAFFS_TRACE_SCAN,
223 " Shadow fixer: %d shadows %d",
231 if (in && in->valid) {
232 /* We have already filled this one.
233 * We have a duplicate and need to
236 unsigned existing_serial = in->serial;
237 unsigned new_serial =
240 if (((existing_serial + 1) & 3) ==
242 /* Use new one - destroy the
249 /* Use existing - destroy
251 yaffs_chunk_del(dev, chunk, 1,
256 if (in && !in->valid &&
257 (tags.obj_id == YAFFS_OBJECTID_ROOT ||
259 YAFFS_OBJECTID_LOSTNFOUND)) {
260 /* We only load some info, don't fiddle
261 * with directory structure */
263 in->variant_type = oh->type;
265 in->yst_mode = oh->yst_mode;
266 yaffs_load_attribs(in, oh);
267 in->hdr_chunk = chunk;
268 in->serial = tags.serial_number;
270 } else if (in && !in->valid) {
271 /* we need to load this info */
274 in->variant_type = oh->type;
276 in->yst_mode = oh->yst_mode;
277 yaffs_load_attribs(in, oh);
278 in->hdr_chunk = chunk;
279 in->serial = tags.serial_number;
281 yaffs_set_obj_name_from_oh(in, oh);
284 /* directory stuff...
289 yaffs_find_or_create_by_number
290 (dev, oh->parent_obj_id,
291 YAFFS_OBJECT_TYPE_DIRECTORY);
294 if (parent && parent->variant_type ==
295 YAFFS_OBJECT_TYPE_UNKNOWN) {
296 /* Set up as a directory */
297 parent->variant_type =
298 YAFFS_OBJECT_TYPE_DIRECTORY;
299 INIT_LIST_HEAD(&parent->
302 } else if (!parent ||
303 parent->variant_type !=
304 YAFFS_OBJECT_TYPE_DIRECTORY) {
305 /* Hoosterman, a problem....
306 * We're trying to use a
307 * non-directory as a directory
310 yaffs_trace(YAFFS_TRACE_ERROR,
311 "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
313 parent = dev->lost_n_found;
316 yaffs_add_obj_to_dir(parent, in);
318 switch (in->variant_type) {
319 case YAFFS_OBJECT_TYPE_UNKNOWN:
320 /* Todo got a problem */
322 case YAFFS_OBJECT_TYPE_FILE:
324 use_header_file_size)
326 file_variant.file_size
327 = yaffs_oh_to_size(oh);
329 case YAFFS_OBJECT_TYPE_HARDLINK:
331 hardlink_variant.equiv_id =
333 list_add(&in->hard_links,
336 case YAFFS_OBJECT_TYPE_DIRECTORY:
339 case YAFFS_OBJECT_TYPE_SPECIAL:
342 case YAFFS_OBJECT_TYPE_SYMLINK:
343 in->variant.symlink_variant.
345 yaffs_clone_str(oh->alias);
347 symlink_variant.alias)
355 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
356 /* If we got this far while scanning,
357 * then the block is fully allocated. */
358 state = YAFFS_BLOCK_STATE_FULL;
361 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
362 /* If the block was partially allocated then
363 * treat it as fully allocated. */
364 state = YAFFS_BLOCK_STATE_FULL;
365 dev->alloc_block = -1;
368 bi->block_state = state;
370 /* Now let's see if it was dirty */
371 if (bi->pages_in_use == 0 &&
372 !bi->has_shrink_hdr &&
373 bi->block_state == YAFFS_BLOCK_STATE_FULL)
374 yaffs_block_became_dirty(dev, blk);
377 /* Ok, we've done all the scanning.
378 * Fix up the hard link chains.
379 * We should now have scanned all the objects, now it's time to add
383 yaffs_link_fixup(dev, &hard_list);
386 * Fix up any shadowed objects.
387 * There should not be more than one of these.
390 struct yaffs_shadow_fixer *fixer;
391 struct yaffs_obj *obj;
393 while (shadow_fixers) {
394 fixer = shadow_fixers;
395 shadow_fixers = fixer->next;
396 /* Complete the rename transaction by deleting the
397 * shadowed object then setting the object header
400 obj = yaffs_find_by_number(dev, fixer->shadowed_id);
404 obj = yaffs_find_by_number(dev, fixer->obj_id);
407 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
413 yaffs_release_temp_buffer(dev, chunk_data);
418 yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");