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 result; 27 int chunk; 28 int c; 29 int deleted; 30 enum yaffs_block_state state; 31 LIST_HEAD(hard_list); 32 struct yaffs_block_info *bi; 33 u32 seq_number; 34 struct yaffs_obj_hdr *oh; 35 struct yaffs_obj *in; 36 struct yaffs_obj *parent; 37 int alloc_failed = 0; 38 struct yaffs_shadow_fixer *shadow_fixers = NULL; 39 u8 *chunk_data; 40 41 yaffs_trace(YAFFS_TRACE_SCAN, 42 "yaffs1_scan starts intstartblk %d intendblk %d...", 43 dev->internal_start_block, dev->internal_end_block); 44 45 chunk_data = yaffs_get_temp_buffer(dev); 46 47 dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER; 48 49 /* Scan all the blocks to determine their state */ 50 bi = dev->block_info; 51 for (blk = dev->internal_start_block; blk <= dev->internal_end_block; 52 blk++) { 53 yaffs_clear_chunk_bits(dev, blk); 54 bi->pages_in_use = 0; 55 bi->soft_del_pages = 0; 56 57 yaffs_query_init_block_state(dev, blk, &state, &seq_number); 58 59 bi->block_state = state; 60 bi->seq_number = seq_number; 61 62 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK) 63 bi->block_state = state = YAFFS_BLOCK_STATE_DEAD; 64 65 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, 66 "Block scanning block %d state %d seq %d", 67 blk, state, seq_number); 68 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; 76 } 77 bi++; 78 } 79 80 /* For each block.... */ 81 for (blk = dev->internal_start_block; 82 !alloc_failed && blk <= dev->internal_end_block; blk++) { 83 84 cond_resched(); 85 86 bi = yaffs_get_block_info(dev, blk); 87 state = bi->block_state; 88 89 deleted = 0; 90 91 /* For each chunk in each block that needs scanning.... */ 92 for (c = 0; 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; 97 98 result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL, 99 &tags); 100 101 /* Let's have a good look at this chunk... */ 102 103 if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED || 104 tags.is_deleted) { 105 /* YAFFS1 only... 106 * A deleted chunk 107 */ 108 deleted++; 109 dev->n_free_chunks++; 110 } else if (!tags.chunk_used) { 111 /* An unassigned chunk in the block 112 * This means that either the block is empty or 113 * this is the one being allocated from 114 */ 115 116 if (c == 0) { 117 /* We're looking at the first chunk in 118 *the block so the block is unused */ 119 state = YAFFS_BLOCK_STATE_EMPTY; 120 dev->n_erased_blocks++; 121 } else { 122 /* this is the block being allocated */ 123 yaffs_trace(YAFFS_TRACE_SCAN, 124 " Allocating from %d %d", 125 blk, c); 126 state = YAFFS_BLOCK_STATE_ALLOCATING; 127 dev->alloc_block = blk; 128 dev->alloc_page = c; 129 dev->alloc_block_finder = blk; 130 131 } 132 133 dev->n_free_chunks += 134 (dev->param.chunks_per_block - c); 135 } else if (tags.chunk_id > 0) { 136 /* chunk_id > 0 so it is a data chunk... */ 137 unsigned int endpos; 138 139 yaffs_set_chunk_bit(dev, blk, c); 140 bi->pages_in_use++; 141 142 in = yaffs_find_or_create_by_number(dev, 143 tags.obj_id, 144 YAFFS_OBJECT_TYPE_FILE); 145 /* PutChunkIntoFile checks for a clash 146 * (two data chunks with the same chunk_id). 147 */ 148 149 if (!in) 150 alloc_failed = 1; 151 152 if (in) { 153 if (!yaffs_put_chunk_in_file 154 (in, tags.chunk_id, chunk, 1)) 155 alloc_failed = 1; 156 } 157 158 endpos = 159 (tags.chunk_id - 1) * 160 dev->data_bytes_per_chunk + 161 tags.n_bytes; 162 if (in && 163 in->variant_type == 164 YAFFS_OBJECT_TYPE_FILE && 165 in->variant.file_variant.scanned_size < 166 endpos) { 167 in->variant.file_variant.scanned_size = 168 endpos; 169 if (!dev->param.use_header_file_size) { 170 in->variant. 171 file_variant.file_size = 172 in->variant. 173 file_variant.scanned_size; 174 } 175 176 } 177 } else { 178 /* chunk_id == 0, so it is an ObjectHeader. 179 * Make the object 180 */ 181 yaffs_set_chunk_bit(dev, blk, c); 182 bi->pages_in_use++; 183 184 result = yaffs_rd_chunk_tags_nand(dev, chunk, 185 chunk_data, 186 NULL); 187 188 oh = (struct yaffs_obj_hdr *)chunk_data; 189 190 in = yaffs_find_by_number(dev, tags.obj_id); 191 if (in && in->variant_type != oh->type) { 192 /* This should not happen, but somehow 193 * Wev'e ended up with an obj_id that 194 * has been reused but not yet deleted, 195 * and worse still it has changed type. 196 * Delete the old object. 197 */ 198 199 yaffs_del_obj(in); 200 in = NULL; 201 } 202 203 in = yaffs_find_or_create_by_number(dev, 204 tags.obj_id, 205 oh->type); 206 207 if (!in) 208 alloc_failed = 1; 209 210 if (in && oh->shadows_obj > 0) { 211 212 struct yaffs_shadow_fixer *fixer; 213 fixer = 214 kmalloc(sizeof 215 (struct yaffs_shadow_fixer), 216 GFP_NOFS); 217 if (fixer) { 218 fixer->next = shadow_fixers; 219 shadow_fixers = fixer; 220 fixer->obj_id = tags.obj_id; 221 fixer->shadowed_id = 222 oh->shadows_obj; 223 yaffs_trace(YAFFS_TRACE_SCAN, 224 " Shadow fixer: %d shadows %d", 225 fixer->obj_id, 226 fixer->shadowed_id); 227 228 } 229 230 } 231 232 if (in && in->valid) { 233 /* We have already filled this one. 234 * We have a duplicate and need to 235 * resolve it. */ 236 237 unsigned existing_serial = in->serial; 238 unsigned new_serial = 239 tags.serial_number; 240 241 if (((existing_serial + 1) & 3) == 242 new_serial) { 243 /* Use new one - destroy the 244 * exisiting one */ 245 yaffs_chunk_del(dev, 246 in->hdr_chunk, 247 1, __LINE__); 248 in->valid = 0; 249 } else { 250 /* Use existing - destroy 251 * this one. */ 252 yaffs_chunk_del(dev, chunk, 1, 253 __LINE__); 254 } 255 } 256 257 if (in && !in->valid && 258 (tags.obj_id == YAFFS_OBJECTID_ROOT || 259 tags.obj_id == 260 YAFFS_OBJECTID_LOSTNFOUND)) { 261 /* We only load some info, don't fiddle 262 * with directory structure */ 263 in->valid = 1; 264 in->variant_type = oh->type; 265 266 in->yst_mode = oh->yst_mode; 267 yaffs_load_attribs(in, oh); 268 in->hdr_chunk = chunk; 269 in->serial = tags.serial_number; 270 271 } else if (in && !in->valid) { 272 /* we need to load this info */ 273 274 in->valid = 1; 275 in->variant_type = oh->type; 276 277 in->yst_mode = oh->yst_mode; 278 yaffs_load_attribs(in, oh); 279 in->hdr_chunk = chunk; 280 in->serial = tags.serial_number; 281 282 yaffs_set_obj_name_from_oh(in, oh); 283 in->dirty = 0; 284 285 /* directory stuff... 286 * hook up to parent 287 */ 288 289 parent = 290 yaffs_find_or_create_by_number 291 (dev, oh->parent_obj_id, 292 YAFFS_OBJECT_TYPE_DIRECTORY); 293 if (!parent) 294 alloc_failed = 1; 295 if (parent && parent->variant_type == 296 YAFFS_OBJECT_TYPE_UNKNOWN) { 297 /* Set up as a directory */ 298 parent->variant_type = 299 YAFFS_OBJECT_TYPE_DIRECTORY; 300 INIT_LIST_HEAD(&parent-> 301 variant.dir_variant. 302 children); 303 } else if (!parent || 304 parent->variant_type != 305 YAFFS_OBJECT_TYPE_DIRECTORY) { 306 /* Hoosterman, a problem.... 307 * We're trying to use a 308 * non-directory as a directory 309 */ 310 311 yaffs_trace(YAFFS_TRACE_ERROR, 312 "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found." 313 ); 314 parent = dev->lost_n_found; 315 } 316 317 yaffs_add_obj_to_dir(parent, in); 318 319 switch (in->variant_type) { 320 case YAFFS_OBJECT_TYPE_UNKNOWN: 321 /* Todo got a problem */ 322 break; 323 case YAFFS_OBJECT_TYPE_FILE: 324 if (dev->param. 325 use_header_file_size) 326 in->variant. 327 file_variant.file_size 328 = yaffs_oh_to_size(oh); 329 break; 330 case YAFFS_OBJECT_TYPE_HARDLINK: 331 in->variant. 332 hardlink_variant.equiv_id = 333 oh->equiv_id; 334 list_add(&in->hard_links, 335 &hard_list); 336 break; 337 case YAFFS_OBJECT_TYPE_DIRECTORY: 338 /* Do nothing */ 339 break; 340 case YAFFS_OBJECT_TYPE_SPECIAL: 341 /* Do nothing */ 342 break; 343 case YAFFS_OBJECT_TYPE_SYMLINK: 344 in->variant.symlink_variant. 345 alias = 346 yaffs_clone_str(oh->alias); 347 if (!in->variant. 348 symlink_variant.alias) 349 alloc_failed = 1; 350 break; 351 } 352 } 353 } 354 } 355 356 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) { 357 /* If we got this far while scanning, 358 * then the block is fully allocated. */ 359 state = YAFFS_BLOCK_STATE_FULL; 360 } 361 362 if (state == YAFFS_BLOCK_STATE_ALLOCATING) { 363 /* If the block was partially allocated then 364 * treat it as fully allocated. */ 365 state = YAFFS_BLOCK_STATE_FULL; 366 dev->alloc_block = -1; 367 } 368 369 bi->block_state = state; 370 371 /* Now let's see if it was dirty */ 372 if (bi->pages_in_use == 0 && 373 !bi->has_shrink_hdr && 374 bi->block_state == YAFFS_BLOCK_STATE_FULL) 375 yaffs_block_became_dirty(dev, blk); 376 } 377 378 /* Ok, we've done all the scanning. 379 * Fix up the hard link chains. 380 * We should now have scanned all the objects, now it's time to add 381 * these hardlinks. 382 */ 383 384 yaffs_link_fixup(dev, &hard_list); 385 386 /* 387 * Fix up any shadowed objects. 388 * There should not be more than one of these. 389 */ 390 { 391 struct yaffs_shadow_fixer *fixer; 392 struct yaffs_obj *obj; 393 394 while (shadow_fixers) { 395 fixer = shadow_fixers; 396 shadow_fixers = fixer->next; 397 /* Complete the rename transaction by deleting the 398 * shadowed object then setting the object header 399 to unshadowed. 400 */ 401 obj = yaffs_find_by_number(dev, fixer->shadowed_id); 402 if (obj) 403 yaffs_del_obj(obj); 404 405 obj = yaffs_find_by_number(dev, fixer->obj_id); 406 407 if (obj) 408 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL); 409 410 kfree(fixer); 411 } 412 } 413 414 yaffs_release_temp_buffer(dev, chunk_data); 415 416 if (alloc_failed) 417 return YAFFS_FAIL; 418 419 yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends"); 420 421 return YAFFS_OK; 422 } 423