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;
30 enum yaffs_block_state state;
32 struct yaffs_block_info *bi;
34 struct yaffs_obj_hdr *oh;
36 struct yaffs_obj *parent;
38 struct yaffs_shadow_fixer *shadow_fixers = NULL;
41 yaffs_trace(YAFFS_TRACE_SCAN,
42 "yaffs1_scan starts intstartblk %d intendblk %d...",
43 dev->internal_start_block, dev->internal_end_block);
45 chunk_data = yaffs_get_temp_buffer(dev);
47 dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
49 /* Scan all the blocks to determine their state */
51 for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
53 yaffs_clear_chunk_bits(dev, blk);
55 bi->soft_del_pages = 0;
57 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
59 bi->block_state = state;
60 bi->seq_number = seq_number;
62 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
63 bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
65 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
66 "Block scanning block %d state %d seq %d",
67 blk, state, seq_number);
69 if (state == YAFFS_BLOCK_STATE_DEAD) {
70 yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
71 "block %d is bad", blk);
72 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
73 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
74 dev->n_erased_blocks++;
75 dev->n_free_chunks += dev->param.chunks_per_block;
80 /* For each block.... */
81 for (blk = dev->internal_start_block;
82 !alloc_failed && blk <= dev->internal_end_block; blk++) {
86 bi = yaffs_get_block_info(dev, blk);
87 state = bi->block_state;
91 /* For each chunk in each block that needs scanning.... */
93 !alloc_failed && c < dev->param.chunks_per_block &&
94 state == YAFFS_BLOCK_STATE_NEEDS_SCAN; c++) {
95 /* Read the tags and decide what to do */
96 chunk = blk * dev->param.chunks_per_block + c;
98 result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
101 if (result != YAFFS_OK)
103 /* Let's have a good look at this chunk... */
105 if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED ||
111 dev->n_free_chunks++;
112 } else if (!tags.chunk_used) {
113 /* An unassigned chunk in the block
114 * This means that either the block is empty or
115 * this is the one being allocated from
119 /* We're looking at the first chunk in
120 *the block so the block is unused */
121 state = YAFFS_BLOCK_STATE_EMPTY;
122 dev->n_erased_blocks++;
124 /* this is the block being allocated */
125 yaffs_trace(YAFFS_TRACE_SCAN,
126 " Allocating from %d %d",
128 state = YAFFS_BLOCK_STATE_ALLOCATING;
129 dev->alloc_block = blk;
131 dev->alloc_block_finder = blk;
135 dev->n_free_chunks +=
136 (dev->param.chunks_per_block - c);
137 } else if (tags.chunk_id > 0) {
138 /* chunk_id > 0 so it is a data chunk... */
141 yaffs_set_chunk_bit(dev, blk, c);
144 in = yaffs_find_or_create_by_number(dev,
146 YAFFS_OBJECT_TYPE_FILE);
147 /* PutChunkIntoFile checks for a clash
148 * (two data chunks with the same chunk_id).
155 if (!yaffs_put_chunk_in_file
156 (in, tags.chunk_id, chunk, 1))
161 (tags.chunk_id - 1) *
162 dev->data_bytes_per_chunk +
166 YAFFS_OBJECT_TYPE_FILE &&
167 in->variant.file_variant.stored_size <
169 in->variant.file_variant.stored_size =
171 if (!dev->param.use_header_file_size) {
173 file_variant.file_size =
175 file_variant.stored_size;
180 /* chunk_id == 0, so it is an ObjectHeader.
183 yaffs_set_chunk_bit(dev, blk, c);
186 result = yaffs_rd_chunk_tags_nand(dev, chunk,
190 oh = (struct yaffs_obj_hdr *)chunk_data;
192 in = yaffs_find_by_number(dev, tags.obj_id);
193 if (in && in->variant_type != oh->type) {
194 /* This should not happen, but somehow
195 * Wev'e ended up with an obj_id that
196 * has been reused but not yet deleted,
197 * and worse still it has changed type.
198 * Delete the old object.
205 in = yaffs_find_or_create_by_number(dev,
212 if (in && oh->shadows_obj > 0) {
214 struct yaffs_shadow_fixer *fixer;
217 (struct yaffs_shadow_fixer),
220 fixer->next = shadow_fixers;
221 shadow_fixers = fixer;
222 fixer->obj_id = tags.obj_id;
225 yaffs_trace(YAFFS_TRACE_SCAN,
226 " Shadow fixer: %d shadows %d",
234 if (in && in->valid) {
235 /* We have already filled this one.
236 * We have a duplicate and need to
239 unsigned existing_serial = in->serial;
240 unsigned new_serial =
243 if (((existing_serial + 1) & 3) ==
245 /* Use new one - destroy the
252 /* Use existing - destroy
254 yaffs_chunk_del(dev, chunk, 1,
259 if (in && !in->valid &&
260 (tags.obj_id == YAFFS_OBJECTID_ROOT ||
262 YAFFS_OBJECTID_LOSTNFOUND)) {
263 /* We only load some info, don't fiddle
264 * with directory structure */
266 in->variant_type = oh->type;
268 in->yst_mode = oh->yst_mode;
269 yaffs_load_attribs(in, oh);
270 in->hdr_chunk = chunk;
271 in->serial = tags.serial_number;
273 } else if (in && !in->valid) {
274 /* we need to load this info */
277 in->variant_type = oh->type;
279 in->yst_mode = oh->yst_mode;
280 yaffs_load_attribs(in, oh);
281 in->hdr_chunk = chunk;
282 in->serial = tags.serial_number;
284 yaffs_set_obj_name_from_oh(in, oh);
287 /* directory stuff...
292 yaffs_find_or_create_by_number
293 (dev, oh->parent_obj_id,
294 YAFFS_OBJECT_TYPE_DIRECTORY);
297 if (parent && parent->variant_type ==
298 YAFFS_OBJECT_TYPE_UNKNOWN) {
299 /* Set up as a directory */
300 parent->variant_type =
301 YAFFS_OBJECT_TYPE_DIRECTORY;
302 INIT_LIST_HEAD(&parent->
305 } else if (!parent ||
306 parent->variant_type !=
307 YAFFS_OBJECT_TYPE_DIRECTORY) {
308 /* Hoosterman, a problem....
309 * We're trying to use a
310 * non-directory as a directory
313 yaffs_trace(YAFFS_TRACE_ERROR,
314 "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
316 parent = dev->lost_n_found;
319 yaffs_add_obj_to_dir(parent, in);
321 switch (in->variant_type) {
322 case YAFFS_OBJECT_TYPE_UNKNOWN:
323 /* Todo got a problem */
325 case YAFFS_OBJECT_TYPE_FILE:
327 use_header_file_size)
329 file_variant.file_size
330 = yaffs_oh_to_size(dev, oh, 0);
332 case YAFFS_OBJECT_TYPE_HARDLINK:
334 hardlink_variant.equiv_id =
336 list_add(&in->hard_links,
339 case YAFFS_OBJECT_TYPE_DIRECTORY:
342 case YAFFS_OBJECT_TYPE_SPECIAL:
345 case YAFFS_OBJECT_TYPE_SYMLINK:
346 in->variant.symlink_variant.
348 yaffs_clone_str(oh->alias);
350 symlink_variant.alias)
358 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
359 /* If we got this far while scanning,
360 * then the block is fully allocated. */
361 state = YAFFS_BLOCK_STATE_FULL;
364 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
365 /* If the block was partially allocated then
366 * treat it as fully allocated. */
367 state = YAFFS_BLOCK_STATE_FULL;
368 dev->alloc_block = -1;
371 bi->block_state = state;
373 /* Now let's see if it was dirty */
374 if (bi->pages_in_use == 0 &&
375 !bi->has_shrink_hdr &&
376 bi->block_state == YAFFS_BLOCK_STATE_FULL)
377 yaffs_block_became_dirty(dev, blk);
380 /* Ok, we've done all the scanning.
381 * Fix up the hard link chains.
382 * We should now have scanned all the objects, now it's time to add
386 yaffs_link_fixup(dev, &hard_list);
389 * Fix up any shadowed objects.
390 * There should not be more than one of these.
393 struct yaffs_shadow_fixer *fixer;
394 struct yaffs_obj *obj;
396 while (shadow_fixers) {
397 fixer = shadow_fixers;
398 shadow_fixers = fixer->next;
399 /* Complete the rename transaction by deleting the
400 * shadowed object then setting the object header
403 obj = yaffs_find_by_number(dev, fixer->shadowed_id);
407 obj = yaffs_find_by_number(dev, fixer->obj_id);
410 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
416 yaffs_release_temp_buffer(dev, chunk_data);
421 yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");