1 /* 2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. 3 * 4 * Copyright (C) 2002-2011 Aleph One Ltd. 5 * for Toby Churchill Ltd and Brightstar Engineering 6 * 7 * Created by Charles Manning <charles@aleph1.co.uk> 8 * 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. 12 */ 13 14 #include "yaffs_yaffs1.h" 15 #include "yportenv.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" 21 22 int yaffs1_scan(struct yaffs_dev *dev) 23 { 24 struct yaffs_ext_tags tags; 25 int blk; 26 int chunk; 27 int c; 28 int deleted; 29 enum yaffs_block_state state; 30 LIST_HEAD(hard_list); 31 struct yaffs_block_info *bi; 32 u32 seq_number; 33 struct yaffs_obj_hdr *oh; 34 struct yaffs_obj *in; 35 struct yaffs_obj *parent; 36 int alloc_failed = 0; 37 struct yaffs_shadow_fixer *shadow_fixers = NULL; 38 u8 *chunk_data; 39 40 yaffs_trace(YAFFS_TRACE_SCAN, 41 "yaffs1_scan starts intstartblk %d intendblk %d...", 42 dev->internal_start_block, dev->internal_end_block); 43 44 chunk_data = yaffs_get_temp_buffer(dev); 45 46 dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER; 47 48 /* Scan all the blocks to determine their state */ 49 bi = dev->block_info; 50 for (blk = dev->internal_start_block; blk <= dev->internal_end_block; 51 blk++) { 52 yaffs_clear_chunk_bits(dev, blk); 53 bi->pages_in_use = 0; 54 bi->soft_del_pages = 0; 55 56 yaffs_query_init_block_state(dev, blk, &state, &seq_number); 57 58 bi->block_state = state; 59 bi->seq_number = seq_number; 60 61 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK) 62 bi->block_state = state = YAFFS_BLOCK_STATE_DEAD; 63 64 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, 65 "Block scanning block %d state %d seq %d", 66 blk, state, seq_number); 67 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; 75 } 76 bi++; 77 } 78 79 /* For each block.... */ 80 for (blk = dev->internal_start_block; 81 !alloc_failed && blk <= dev->internal_end_block; blk++) { 82 83 cond_resched(); 84 85 bi = yaffs_get_block_info(dev, blk); 86 state = bi->block_state; 87 88 deleted = 0; 89 90 /* For each chunk in each block that needs scanning.... */ 91 for (c = 0; 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; 96 97 yaffs_rd_chunk_tags_nand(dev, chunk, NULL, &tags); 98 99 /* Let's have a good look at this chunk... */ 100 101 if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED || 102 tags.is_deleted) { 103 /* YAFFS1 only... 104 * A deleted chunk 105 */ 106 deleted++; 107 dev->n_free_chunks++; 108 } else if (!tags.chunk_used) { 109 /* An unassigned chunk in the block 110 * This means that either the block is empty or 111 * this is the one being allocated from 112 */ 113 114 if (c == 0) { 115 /* We're looking at the first chunk in 116 *the block so the block is unused */ 117 state = YAFFS_BLOCK_STATE_EMPTY; 118 dev->n_erased_blocks++; 119 } else { 120 /* this is the block being allocated */ 121 yaffs_trace(YAFFS_TRACE_SCAN, 122 " Allocating from %d %d", 123 blk, c); 124 state = YAFFS_BLOCK_STATE_ALLOCATING; 125 dev->alloc_block = blk; 126 dev->alloc_page = c; 127 dev->alloc_block_finder = blk; 128 129 } 130 131 dev->n_free_chunks += 132 (dev->param.chunks_per_block - c); 133 } else if (tags.chunk_id > 0) { 134 /* chunk_id > 0 so it is a data chunk... */ 135 unsigned int endpos; 136 137 yaffs_set_chunk_bit(dev, blk, c); 138 bi->pages_in_use++; 139 140 in = yaffs_find_or_create_by_number(dev, 141 tags.obj_id, 142 YAFFS_OBJECT_TYPE_FILE); 143 /* PutChunkIntoFile checks for a clash 144 * (two data chunks with the same chunk_id). 145 */ 146 147 if (!in) 148 alloc_failed = 1; 149 150 if (in) { 151 if (!yaffs_put_chunk_in_file 152 (in, tags.chunk_id, chunk, 1)) 153 alloc_failed = 1; 154 } 155 156 endpos = 157 (tags.chunk_id - 1) * 158 dev->data_bytes_per_chunk + 159 tags.n_bytes; 160 if (in && 161 in->variant_type == 162 YAFFS_OBJECT_TYPE_FILE && 163 in->variant.file_variant.scanned_size < 164 endpos) { 165 in->variant.file_variant.scanned_size = 166 endpos; 167 if (!dev->param.use_header_file_size) { 168 in->variant. 169 file_variant.file_size = 170 in->variant. 171 file_variant.scanned_size; 172 } 173 174 } 175 } else { 176 /* chunk_id == 0, so it is an ObjectHeader. 177 * Make the object 178 */ 179 yaffs_set_chunk_bit(dev, blk, c); 180 bi->pages_in_use++; 181 182 yaffs_rd_chunk_tags_nand(dev, chunk, 183 chunk_data, NULL); 184 185 oh = (struct yaffs_obj_hdr *)chunk_data; 186 187 in = yaffs_find_by_number(dev, tags.obj_id); 188 if (in && in->variant_type != oh->type) { 189 /* This should not happen, but somehow 190 * Wev'e ended up with an obj_id that 191 * has been reused but not yet deleted, 192 * and worse still it has changed type. 193 * Delete the old object. 194 */ 195 196 yaffs_del_obj(in); 197 in = NULL; 198 } 199 200 in = yaffs_find_or_create_by_number(dev, 201 tags.obj_id, 202 oh->type); 203 204 if (!in) 205 alloc_failed = 1; 206 207 if (in && oh->shadows_obj > 0) { 208 209 struct yaffs_shadow_fixer *fixer; 210 fixer = 211 kmalloc(sizeof 212 (struct yaffs_shadow_fixer), 213 GFP_NOFS); 214 if (fixer) { 215 fixer->next = shadow_fixers; 216 shadow_fixers = fixer; 217 fixer->obj_id = tags.obj_id; 218 fixer->shadowed_id = 219 oh->shadows_obj; 220 yaffs_trace(YAFFS_TRACE_SCAN, 221 " Shadow fixer: %d shadows %d", 222 fixer->obj_id, 223 fixer->shadowed_id); 224 225 } 226 227 } 228 229 if (in && in->valid) { 230 /* We have already filled this one. 231 * We have a duplicate and need to 232 * resolve it. */ 233 234 unsigned existing_serial = in->serial; 235 unsigned new_serial = 236 tags.serial_number; 237 238 if (((existing_serial + 1) & 3) == 239 new_serial) { 240 /* Use new one - destroy the 241 * exisiting one */ 242 yaffs_chunk_del(dev, 243 in->hdr_chunk, 244 1, __LINE__); 245 in->valid = 0; 246 } else { 247 /* Use existing - destroy 248 * this one. */ 249 yaffs_chunk_del(dev, chunk, 1, 250 __LINE__); 251 } 252 } 253 254 if (in && !in->valid && 255 (tags.obj_id == YAFFS_OBJECTID_ROOT || 256 tags.obj_id == 257 YAFFS_OBJECTID_LOSTNFOUND)) { 258 /* We only load some info, don't fiddle 259 * with directory structure */ 260 in->valid = 1; 261 in->variant_type = oh->type; 262 263 in->yst_mode = oh->yst_mode; 264 yaffs_load_attribs(in, oh); 265 in->hdr_chunk = chunk; 266 in->serial = tags.serial_number; 267 268 } else if (in && !in->valid) { 269 /* we need to load this info */ 270 271 in->valid = 1; 272 in->variant_type = oh->type; 273 274 in->yst_mode = oh->yst_mode; 275 yaffs_load_attribs(in, oh); 276 in->hdr_chunk = chunk; 277 in->serial = tags.serial_number; 278 279 yaffs_set_obj_name_from_oh(in, oh); 280 in->dirty = 0; 281 282 /* directory stuff... 283 * hook up to parent 284 */ 285 286 parent = 287 yaffs_find_or_create_by_number 288 (dev, oh->parent_obj_id, 289 YAFFS_OBJECT_TYPE_DIRECTORY); 290 if (!parent) 291 alloc_failed = 1; 292 if (parent && parent->variant_type == 293 YAFFS_OBJECT_TYPE_UNKNOWN) { 294 /* Set up as a directory */ 295 parent->variant_type = 296 YAFFS_OBJECT_TYPE_DIRECTORY; 297 INIT_LIST_HEAD(&parent-> 298 variant.dir_variant. 299 children); 300 } else if (!parent || 301 parent->variant_type != 302 YAFFS_OBJECT_TYPE_DIRECTORY) { 303 /* Hoosterman, a problem.... 304 * We're trying to use a 305 * non-directory as a directory 306 */ 307 308 yaffs_trace(YAFFS_TRACE_ERROR, 309 "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found." 310 ); 311 parent = dev->lost_n_found; 312 } 313 314 yaffs_add_obj_to_dir(parent, in); 315 316 switch (in->variant_type) { 317 case YAFFS_OBJECT_TYPE_UNKNOWN: 318 /* Todo got a problem */ 319 break; 320 case YAFFS_OBJECT_TYPE_FILE: 321 if (dev->param. 322 use_header_file_size) 323 in->variant. 324 file_variant.file_size 325 = yaffs_oh_to_size(oh); 326 break; 327 case YAFFS_OBJECT_TYPE_HARDLINK: 328 in->variant. 329 hardlink_variant.equiv_id = 330 oh->equiv_id; 331 list_add(&in->hard_links, 332 &hard_list); 333 break; 334 case YAFFS_OBJECT_TYPE_DIRECTORY: 335 /* Do nothing */ 336 break; 337 case YAFFS_OBJECT_TYPE_SPECIAL: 338 /* Do nothing */ 339 break; 340 case YAFFS_OBJECT_TYPE_SYMLINK: 341 in->variant.symlink_variant. 342 alias = 343 yaffs_clone_str(oh->alias); 344 if (!in->variant. 345 symlink_variant.alias) 346 alloc_failed = 1; 347 break; 348 } 349 } 350 } 351 } 352 353 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) { 354 /* If we got this far while scanning, 355 * then the block is fully allocated. */ 356 state = YAFFS_BLOCK_STATE_FULL; 357 } 358 359 if (state == YAFFS_BLOCK_STATE_ALLOCATING) { 360 /* If the block was partially allocated then 361 * treat it as fully allocated. */ 362 state = YAFFS_BLOCK_STATE_FULL; 363 dev->alloc_block = -1; 364 } 365 366 bi->block_state = state; 367 368 /* Now let's see if it was dirty */ 369 if (bi->pages_in_use == 0 && 370 !bi->has_shrink_hdr && 371 bi->block_state == YAFFS_BLOCK_STATE_FULL) 372 yaffs_block_became_dirty(dev, blk); 373 } 374 375 /* Ok, we've done all the scanning. 376 * Fix up the hard link chains. 377 * We should now have scanned all the objects, now it's time to add 378 * these hardlinks. 379 */ 380 381 yaffs_link_fixup(dev, &hard_list); 382 383 /* 384 * Fix up any shadowed objects. 385 * There should not be more than one of these. 386 */ 387 { 388 struct yaffs_shadow_fixer *fixer; 389 struct yaffs_obj *obj; 390 391 while (shadow_fixers) { 392 fixer = shadow_fixers; 393 shadow_fixers = fixer->next; 394 /* Complete the rename transaction by deleting the 395 * shadowed object then setting the object header 396 to unshadowed. 397 */ 398 obj = yaffs_find_by_number(dev, fixer->shadowed_id); 399 if (obj) 400 yaffs_del_obj(obj); 401 402 obj = yaffs_find_by_number(dev, fixer->obj_id); 403 404 if (obj) 405 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL); 406 407 kfree(fixer); 408 } 409 } 410 411 yaffs_release_temp_buffer(dev, chunk_data); 412 413 if (alloc_failed) 414 return YAFFS_FAIL; 415 416 yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends"); 417 418 return YAFFS_OK; 419 } 420