1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright © 2001-2007 Red Hat, Inc. 5 * 6 * Created by David Woodhouse <dwmw2@infradead.org> 7 * 8 * For licensing information, see the file 'LICENCE' in this directory. 9 * 10 */ 11 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/kernel.h> 15 #include <linux/mtd/mtd.h> 16 #include <linux/compiler.h> 17 #include <linux/sched.h> /* For cond_resched() */ 18 #include "nodelist.h" 19 #include "debug.h" 20 21 /* 22 * Check whether the user is allowed to write. 23 */ 24 static int jffs2_rp_can_write(struct jffs2_sb_info *c) 25 { 26 uint32_t avail; 27 struct jffs2_mount_opts *opts = &c->mount_opts; 28 29 avail = c->dirty_size + c->free_size + c->unchecked_size + 30 c->erasing_size - c->resv_blocks_write * c->sector_size 31 - c->nospc_dirty_size; 32 33 if (avail < 2 * opts->rp_size) 34 jffs2_dbg(1, "rpsize %u, dirty_size %u, free_size %u, " 35 "erasing_size %u, unchecked_size %u, " 36 "nr_erasing_blocks %u, avail %u, resrv %u\n", 37 opts->rp_size, c->dirty_size, c->free_size, 38 c->erasing_size, c->unchecked_size, 39 c->nr_erasing_blocks, avail, c->nospc_dirty_size); 40 41 if (avail > opts->rp_size) 42 return 1; 43 44 /* Always allow root */ 45 if (capable(CAP_SYS_RESOURCE)) 46 return 1; 47 48 jffs2_dbg(1, "forbid writing\n"); 49 return 0; 50 } 51 52 /** 53 * jffs2_reserve_space - request physical space to write nodes to flash 54 * @c: superblock info 55 * @minsize: Minimum acceptable size of allocation 56 * @len: Returned value of allocation length 57 * @prio: Allocation type - ALLOC_{NORMAL,DELETION} 58 * 59 * Requests a block of physical space on the flash. Returns zero for success 60 * and puts 'len' into the appropriate place, or returns -ENOSPC or other 61 * error if appropriate. Doesn't return len since that's 62 * 63 * If it returns zero, jffs2_reserve_space() also downs the per-filesystem 64 * allocation semaphore, to prevent more than one allocation from being 65 * active at any time. The semaphore is later released by jffs2_commit_allocation() 66 * 67 * jffs2_reserve_space() may trigger garbage collection in order to make room 68 * for the requested allocation. 69 */ 70 71 static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, 72 uint32_t *len, uint32_t sumsize); 73 74 int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, 75 uint32_t *len, int prio, uint32_t sumsize) 76 { 77 int ret = -EAGAIN; 78 int blocksneeded = c->resv_blocks_write; 79 /* align it */ 80 minsize = PAD(minsize); 81 82 jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize); 83 mutex_lock(&c->alloc_sem); 84 85 jffs2_dbg(1, "%s(): alloc sem got\n", __func__); 86 87 spin_lock(&c->erase_completion_lock); 88 89 /* 90 * Check if the free space is greater then size of the reserved pool. 91 * If not, only allow root to proceed with writing. 92 */ 93 if (prio != ALLOC_DELETION && !jffs2_rp_can_write(c)) { 94 ret = -ENOSPC; 95 goto out; 96 } 97 98 /* this needs a little more thought (true <tglx> :)) */ 99 while(ret == -EAGAIN) { 100 while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) { 101 uint32_t dirty, avail; 102 103 /* calculate real dirty size 104 * dirty_size contains blocks on erase_pending_list 105 * those blocks are counted in c->nr_erasing_blocks. 106 * If one block is actually erased, it is not longer counted as dirty_space 107 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it 108 * with c->nr_erasing_blocks * c->sector_size again. 109 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks 110 * This helps us to force gc and pick eventually a clean block to spread the load. 111 * We add unchecked_size here, as we hopefully will find some space to use. 112 * This will affect the sum only once, as gc first finishes checking 113 * of nodes. 114 */ 115 dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size; 116 if (dirty < c->nospc_dirty_size) { 117 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) { 118 jffs2_dbg(1, "%s(): Low on dirty space to GC, but it's a deletion. Allowing...\n", 119 __func__); 120 break; 121 } 122 jffs2_dbg(1, "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n", 123 dirty, c->unchecked_size, 124 c->sector_size); 125 126 spin_unlock(&c->erase_completion_lock); 127 mutex_unlock(&c->alloc_sem); 128 return -ENOSPC; 129 } 130 131 /* Calc possibly available space. Possibly available means that we 132 * don't know, if unchecked size contains obsoleted nodes, which could give us some 133 * more usable space. This will affect the sum only once, as gc first finishes checking 134 * of nodes. 135 + Return -ENOSPC, if the maximum possibly available space is less or equal than 136 * blocksneeded * sector_size. 137 * This blocks endless gc looping on a filesystem, which is nearly full, even if 138 * the check above passes. 139 */ 140 avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size; 141 if ( (avail / c->sector_size) <= blocksneeded) { 142 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) { 143 jffs2_dbg(1, "%s(): Low on possibly available space, but it's a deletion. Allowing...\n", 144 __func__); 145 break; 146 } 147 148 jffs2_dbg(1, "max. available size 0x%08x < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n", 149 avail, blocksneeded * c->sector_size); 150 spin_unlock(&c->erase_completion_lock); 151 mutex_unlock(&c->alloc_sem); 152 return -ENOSPC; 153 } 154 155 mutex_unlock(&c->alloc_sem); 156 157 jffs2_dbg(1, "Triggering GC pass. nr_free_blocks %d, nr_erasing_blocks %d, free_size 0x%08x, dirty_size 0x%08x, wasted_size 0x%08x, used_size 0x%08x, erasing_size 0x%08x, bad_size 0x%08x (total 0x%08x of 0x%08x)\n", 158 c->nr_free_blocks, c->nr_erasing_blocks, 159 c->free_size, c->dirty_size, c->wasted_size, 160 c->used_size, c->erasing_size, c->bad_size, 161 c->free_size + c->dirty_size + 162 c->wasted_size + c->used_size + 163 c->erasing_size + c->bad_size, 164 c->flash_size); 165 spin_unlock(&c->erase_completion_lock); 166 167 ret = jffs2_garbage_collect_pass(c); 168 169 if (ret == -EAGAIN) { 170 spin_lock(&c->erase_completion_lock); 171 if (c->nr_erasing_blocks && 172 list_empty(&c->erase_pending_list) && 173 list_empty(&c->erase_complete_list)) { 174 DECLARE_WAITQUEUE(wait, current); 175 set_current_state(TASK_UNINTERRUPTIBLE); 176 add_wait_queue(&c->erase_wait, &wait); 177 jffs2_dbg(1, "%s waiting for erase to complete\n", 178 __func__); 179 spin_unlock(&c->erase_completion_lock); 180 181 schedule(); 182 } else 183 spin_unlock(&c->erase_completion_lock); 184 } else if (ret) 185 return ret; 186 187 cond_resched(); 188 189 if (signal_pending(current)) 190 return -EINTR; 191 192 mutex_lock(&c->alloc_sem); 193 spin_lock(&c->erase_completion_lock); 194 } 195 196 ret = jffs2_do_reserve_space(c, minsize, len, sumsize); 197 if (ret) { 198 jffs2_dbg(1, "%s(): ret is %d\n", __func__, ret); 199 } 200 } 201 202 out: 203 spin_unlock(&c->erase_completion_lock); 204 if (!ret) 205 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 206 if (ret) 207 mutex_unlock(&c->alloc_sem); 208 return ret; 209 } 210 211 int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize, 212 uint32_t *len, uint32_t sumsize) 213 { 214 int ret = -EAGAIN; 215 minsize = PAD(minsize); 216 217 jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize); 218 219 spin_lock(&c->erase_completion_lock); 220 while(ret == -EAGAIN) { 221 ret = jffs2_do_reserve_space(c, minsize, len, sumsize); 222 if (ret) { 223 jffs2_dbg(1, "%s(): looping, ret is %d\n", 224 __func__, ret); 225 } 226 } 227 spin_unlock(&c->erase_completion_lock); 228 if (!ret) 229 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 230 231 return ret; 232 } 233 234 235 /* Classify nextblock (clean, dirty of verydirty) and force to select an other one */ 236 237 static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 238 { 239 240 if (c->nextblock == NULL) { 241 jffs2_dbg(1, "%s(): Erase block at 0x%08x has already been placed in a list\n", 242 __func__, jeb->offset); 243 return; 244 } 245 /* Check, if we have a dirty block now, or if it was dirty already */ 246 if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) { 247 c->dirty_size += jeb->wasted_size; 248 c->wasted_size -= jeb->wasted_size; 249 jeb->dirty_size += jeb->wasted_size; 250 jeb->wasted_size = 0; 251 if (VERYDIRTY(c, jeb->dirty_size)) { 252 jffs2_dbg(1, "Adding full erase block at 0x%08x to very_dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n", 253 jeb->offset, jeb->free_size, jeb->dirty_size, 254 jeb->used_size); 255 list_add_tail(&jeb->list, &c->very_dirty_list); 256 } else { 257 jffs2_dbg(1, "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n", 258 jeb->offset, jeb->free_size, jeb->dirty_size, 259 jeb->used_size); 260 list_add_tail(&jeb->list, &c->dirty_list); 261 } 262 } else { 263 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n", 264 jeb->offset, jeb->free_size, jeb->dirty_size, 265 jeb->used_size); 266 list_add_tail(&jeb->list, &c->clean_list); 267 } 268 c->nextblock = NULL; 269 270 } 271 272 /* Select a new jeb for nextblock */ 273 274 static int jffs2_find_nextblock(struct jffs2_sb_info *c) 275 { 276 struct list_head *next; 277 278 /* Take the next block off the 'free' list */ 279 280 if (list_empty(&c->free_list)) { 281 282 if (!c->nr_erasing_blocks && 283 !list_empty(&c->erasable_list)) { 284 struct jffs2_eraseblock *ejeb; 285 286 ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list); 287 list_move_tail(&ejeb->list, &c->erase_pending_list); 288 c->nr_erasing_blocks++; 289 jffs2_garbage_collect_trigger(c); 290 jffs2_dbg(1, "%s(): Triggering erase of erasable block at 0x%08x\n", 291 __func__, ejeb->offset); 292 } 293 294 if (!c->nr_erasing_blocks && 295 !list_empty(&c->erasable_pending_wbuf_list)) { 296 jffs2_dbg(1, "%s(): Flushing write buffer\n", 297 __func__); 298 /* c->nextblock is NULL, no update to c->nextblock allowed */ 299 spin_unlock(&c->erase_completion_lock); 300 jffs2_flush_wbuf_pad(c); 301 spin_lock(&c->erase_completion_lock); 302 /* Have another go. It'll be on the erasable_list now */ 303 return -EAGAIN; 304 } 305 306 if (!c->nr_erasing_blocks) { 307 /* Ouch. We're in GC, or we wouldn't have got here. 308 And there's no space left. At all. */ 309 pr_crit("Argh. No free space left for GC. nr_erasing_blocks is %d. nr_free_blocks is %d. (erasableempty: %s, erasingempty: %s, erasependingempty: %s)\n", 310 c->nr_erasing_blocks, c->nr_free_blocks, 311 list_empty(&c->erasable_list) ? "yes" : "no", 312 list_empty(&c->erasing_list) ? "yes" : "no", 313 list_empty(&c->erase_pending_list) ? "yes" : "no"); 314 return -ENOSPC; 315 } 316 317 spin_unlock(&c->erase_completion_lock); 318 /* Don't wait for it; just erase one right now */ 319 jffs2_erase_pending_blocks(c, 1); 320 spin_lock(&c->erase_completion_lock); 321 322 /* An erase may have failed, decreasing the 323 amount of free space available. So we must 324 restart from the beginning */ 325 return -EAGAIN; 326 } 327 328 next = c->free_list.next; 329 list_del(next); 330 c->nextblock = list_entry(next, struct jffs2_eraseblock, list); 331 c->nr_free_blocks--; 332 333 jffs2_sum_reset_collected(c->summary); /* reset collected summary */ 334 335 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 336 /* adjust write buffer offset, else we get a non contiguous write bug */ 337 if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len) 338 c->wbuf_ofs = 0xffffffff; 339 #endif 340 341 jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n", 342 __func__, c->nextblock->offset); 343 344 return 0; 345 } 346 347 /* Called with alloc sem _and_ erase_completion_lock */ 348 static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, 349 uint32_t *len, uint32_t sumsize) 350 { 351 struct jffs2_eraseblock *jeb = c->nextblock; 352 uint32_t reserved_size; /* for summary information at the end of the jeb */ 353 int ret; 354 355 restart: 356 reserved_size = 0; 357 358 if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) { 359 /* NOSUM_SIZE means not to generate summary */ 360 361 if (jeb) { 362 reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE); 363 dbg_summary("minsize=%d , jeb->free=%d ," 364 "summary->size=%d , sumsize=%d\n", 365 minsize, jeb->free_size, 366 c->summary->sum_size, sumsize); 367 } 368 369 /* Is there enough space for writing out the current node, or we have to 370 write out summary information now, close this jeb and select new nextblock? */ 371 if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize + 372 JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) { 373 374 /* Has summary been disabled for this jeb? */ 375 if (jffs2_sum_is_disabled(c->summary)) { 376 sumsize = JFFS2_SUMMARY_NOSUM_SIZE; 377 goto restart; 378 } 379 380 /* Writing out the collected summary information */ 381 dbg_summary("generating summary for 0x%08x.\n", jeb->offset); 382 ret = jffs2_sum_write_sumnode(c); 383 384 if (ret) 385 return ret; 386 387 if (jffs2_sum_is_disabled(c->summary)) { 388 /* jffs2_write_sumnode() couldn't write out the summary information 389 diabling summary for this jeb and free the collected information 390 */ 391 sumsize = JFFS2_SUMMARY_NOSUM_SIZE; 392 goto restart; 393 } 394 395 jffs2_close_nextblock(c, jeb); 396 jeb = NULL; 397 /* keep always valid value in reserved_size */ 398 reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE); 399 } 400 } else { 401 if (jeb && minsize > jeb->free_size) { 402 uint32_t waste; 403 404 /* Skip the end of this block and file it as having some dirty space */ 405 /* If there's a pending write to it, flush now */ 406 407 if (jffs2_wbuf_dirty(c)) { 408 spin_unlock(&c->erase_completion_lock); 409 jffs2_dbg(1, "%s(): Flushing write buffer\n", 410 __func__); 411 jffs2_flush_wbuf_pad(c); 412 spin_lock(&c->erase_completion_lock); 413 jeb = c->nextblock; 414 goto restart; 415 } 416 417 spin_unlock(&c->erase_completion_lock); 418 419 ret = jffs2_prealloc_raw_node_refs(c, jeb, 1); 420 421 /* Just lock it again and continue. Nothing much can change because 422 we hold c->alloc_sem anyway. In fact, it's not entirely clear why 423 we hold c->erase_completion_lock in the majority of this function... 424 but that's a question for another (more caffeine-rich) day. */ 425 spin_lock(&c->erase_completion_lock); 426 427 if (ret) 428 return ret; 429 430 waste = jeb->free_size; 431 jffs2_link_node_ref(c, jeb, 432 (jeb->offset + c->sector_size - waste) | REF_OBSOLETE, 433 waste, NULL); 434 /* FIXME: that made it count as dirty. Convert to wasted */ 435 jeb->dirty_size -= waste; 436 c->dirty_size -= waste; 437 jeb->wasted_size += waste; 438 c->wasted_size += waste; 439 440 jffs2_close_nextblock(c, jeb); 441 jeb = NULL; 442 } 443 } 444 445 if (!jeb) { 446 447 ret = jffs2_find_nextblock(c); 448 if (ret) 449 return ret; 450 451 jeb = c->nextblock; 452 453 if (jeb->free_size != c->sector_size - c->cleanmarker_size) { 454 pr_warn("Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", 455 jeb->offset, jeb->free_size); 456 goto restart; 457 } 458 } 459 /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has 460 enough space */ 461 *len = jeb->free_size - reserved_size; 462 463 if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size && 464 !jeb->first_node->next_in_ino) { 465 /* Only node in it beforehand was a CLEANMARKER node (we think). 466 So mark it obsolete now that there's going to be another node 467 in the block. This will reduce used_size to zero but We've 468 already set c->nextblock so that jffs2_mark_node_obsolete() 469 won't try to refile it to the dirty_list. 470 */ 471 spin_unlock(&c->erase_completion_lock); 472 jffs2_mark_node_obsolete(c, jeb->first_node); 473 spin_lock(&c->erase_completion_lock); 474 } 475 476 jffs2_dbg(1, "%s(): Giving 0x%x bytes at 0x%x\n", 477 __func__, 478 *len, jeb->offset + (c->sector_size - jeb->free_size)); 479 return 0; 480 } 481 482 /** 483 * jffs2_add_physical_node_ref - add a physical node reference to the list 484 * @c: superblock info 485 * @new: new node reference to add 486 * @len: length of this physical node 487 * 488 * Should only be used to report nodes for which space has been allocated 489 * by jffs2_reserve_space. 490 * 491 * Must be called with the alloc_sem held. 492 */ 493 494 struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c, 495 uint32_t ofs, uint32_t len, 496 struct jffs2_inode_cache *ic) 497 { 498 struct jffs2_eraseblock *jeb; 499 struct jffs2_raw_node_ref *new; 500 501 jeb = &c->blocks[ofs / c->sector_size]; 502 503 jffs2_dbg(1, "%s(): Node at 0x%x(%d), size 0x%x\n", 504 __func__, ofs & ~3, ofs & 3, len); 505 #if 1 506 /* Allow non-obsolete nodes only to be added at the end of c->nextblock, 507 if c->nextblock is set. Note that wbuf.c will file obsolete nodes 508 even after refiling c->nextblock */ 509 if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE)) 510 && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) { 511 pr_warn("argh. node added in wrong place at 0x%08x(%d)\n", 512 ofs & ~3, ofs & 3); 513 if (c->nextblock) 514 pr_warn("nextblock 0x%08x", c->nextblock->offset); 515 else 516 pr_warn("No nextblock"); 517 pr_cont(", expected at %08x\n", 518 jeb->offset + (c->sector_size - jeb->free_size)); 519 return ERR_PTR(-EINVAL); 520 } 521 #endif 522 spin_lock(&c->erase_completion_lock); 523 524 new = jffs2_link_node_ref(c, jeb, ofs, len, ic); 525 526 if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) { 527 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */ 528 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n", 529 jeb->offset, jeb->free_size, jeb->dirty_size, 530 jeb->used_size); 531 if (jffs2_wbuf_dirty(c)) { 532 /* Flush the last write in the block if it's outstanding */ 533 spin_unlock(&c->erase_completion_lock); 534 jffs2_flush_wbuf_pad(c); 535 spin_lock(&c->erase_completion_lock); 536 } 537 538 list_add_tail(&jeb->list, &c->clean_list); 539 c->nextblock = NULL; 540 } 541 jffs2_dbg_acct_sanity_check_nolock(c,jeb); 542 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 543 544 spin_unlock(&c->erase_completion_lock); 545 546 return new; 547 } 548 549 550 void jffs2_complete_reservation(struct jffs2_sb_info *c) 551 { 552 jffs2_dbg(1, "jffs2_complete_reservation()\n"); 553 spin_lock(&c->erase_completion_lock); 554 jffs2_garbage_collect_trigger(c); 555 spin_unlock(&c->erase_completion_lock); 556 mutex_unlock(&c->alloc_sem); 557 } 558 559 static inline int on_list(struct list_head *obj, struct list_head *head) 560 { 561 struct list_head *this; 562 563 list_for_each(this, head) { 564 if (this == obj) { 565 jffs2_dbg(1, "%p is on list at %p\n", obj, head); 566 return 1; 567 568 } 569 } 570 return 0; 571 } 572 573 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref) 574 { 575 struct jffs2_eraseblock *jeb; 576 int blocknr; 577 struct jffs2_unknown_node n; 578 int ret, addedsize; 579 size_t retlen; 580 uint32_t freed_len; 581 582 if(unlikely(!ref)) { 583 pr_notice("EEEEEK. jffs2_mark_node_obsolete called with NULL node\n"); 584 return; 585 } 586 if (ref_obsolete(ref)) { 587 jffs2_dbg(1, "%s(): called with already obsolete node at 0x%08x\n", 588 __func__, ref_offset(ref)); 589 return; 590 } 591 blocknr = ref->flash_offset / c->sector_size; 592 if (blocknr >= c->nr_blocks) { 593 pr_notice("raw node at 0x%08x is off the end of device!\n", 594 ref->flash_offset); 595 BUG(); 596 } 597 jeb = &c->blocks[blocknr]; 598 599 if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) && 600 !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) { 601 /* Hm. This may confuse static lock analysis. If any of the above 602 three conditions is false, we're going to return from this 603 function without actually obliterating any nodes or freeing 604 any jffs2_raw_node_refs. So we don't need to stop erases from 605 happening, or protect against people holding an obsolete 606 jffs2_raw_node_ref without the erase_completion_lock. */ 607 mutex_lock(&c->erase_free_sem); 608 } 609 610 spin_lock(&c->erase_completion_lock); 611 612 freed_len = ref_totlen(c, jeb, ref); 613 614 if (ref_flags(ref) == REF_UNCHECKED) { 615 D1(if (unlikely(jeb->unchecked_size < freed_len)) { 616 pr_notice("raw unchecked node of size 0x%08x freed from erase block %d at 0x%08x, but unchecked_size was already 0x%08x\n", 617 freed_len, blocknr, 618 ref->flash_offset, jeb->used_size); 619 BUG(); 620 }) 621 jffs2_dbg(1, "Obsoleting previously unchecked node at 0x%08x of len %x\n", 622 ref_offset(ref), freed_len); 623 jeb->unchecked_size -= freed_len; 624 c->unchecked_size -= freed_len; 625 } else { 626 D1(if (unlikely(jeb->used_size < freed_len)) { 627 pr_notice("raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n", 628 freed_len, blocknr, 629 ref->flash_offset, jeb->used_size); 630 BUG(); 631 }) 632 jffs2_dbg(1, "Obsoleting node at 0x%08x of len %#x: ", 633 ref_offset(ref), freed_len); 634 jeb->used_size -= freed_len; 635 c->used_size -= freed_len; 636 } 637 638 // Take care, that wasted size is taken into concern 639 if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) { 640 jffs2_dbg(1, "Dirtying\n"); 641 addedsize = freed_len; 642 jeb->dirty_size += freed_len; 643 c->dirty_size += freed_len; 644 645 /* Convert wasted space to dirty, if not a bad block */ 646 if (jeb->wasted_size) { 647 if (on_list(&jeb->list, &c->bad_used_list)) { 648 jffs2_dbg(1, "Leaving block at %08x on the bad_used_list\n", 649 jeb->offset); 650 addedsize = 0; /* To fool the refiling code later */ 651 } else { 652 jffs2_dbg(1, "Converting %d bytes of wasted space to dirty in block at %08x\n", 653 jeb->wasted_size, jeb->offset); 654 addedsize += jeb->wasted_size; 655 jeb->dirty_size += jeb->wasted_size; 656 c->dirty_size += jeb->wasted_size; 657 c->wasted_size -= jeb->wasted_size; 658 jeb->wasted_size = 0; 659 } 660 } 661 } else { 662 jffs2_dbg(1, "Wasting\n"); 663 addedsize = 0; 664 jeb->wasted_size += freed_len; 665 c->wasted_size += freed_len; 666 } 667 ref->flash_offset = ref_offset(ref) | REF_OBSOLETE; 668 669 jffs2_dbg_acct_sanity_check_nolock(c, jeb); 670 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 671 672 if (c->flags & JFFS2_SB_FLAG_SCANNING) { 673 /* Flash scanning is in progress. Don't muck about with the block 674 lists because they're not ready yet, and don't actually 675 obliterate nodes that look obsolete. If they weren't 676 marked obsolete on the flash at the time they _became_ 677 obsolete, there was probably a reason for that. */ 678 spin_unlock(&c->erase_completion_lock); 679 /* We didn't lock the erase_free_sem */ 680 return; 681 } 682 683 if (jeb == c->nextblock) { 684 jffs2_dbg(2, "Not moving nextblock 0x%08x to dirty/erase_pending list\n", 685 jeb->offset); 686 } else if (!jeb->used_size && !jeb->unchecked_size) { 687 if (jeb == c->gcblock) { 688 jffs2_dbg(1, "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", 689 jeb->offset); 690 c->gcblock = NULL; 691 } else { 692 jffs2_dbg(1, "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", 693 jeb->offset); 694 list_del(&jeb->list); 695 } 696 if (jffs2_wbuf_dirty(c)) { 697 jffs2_dbg(1, "...and adding to erasable_pending_wbuf_list\n"); 698 list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list); 699 } else { 700 if (jiffies & 127) { 701 /* Most of the time, we just erase it immediately. Otherwise we 702 spend ages scanning it on mount, etc. */ 703 jffs2_dbg(1, "...and adding to erase_pending_list\n"); 704 list_add_tail(&jeb->list, &c->erase_pending_list); 705 c->nr_erasing_blocks++; 706 jffs2_garbage_collect_trigger(c); 707 } else { 708 /* Sometimes, however, we leave it elsewhere so it doesn't get 709 immediately reused, and we spread the load a bit. */ 710 jffs2_dbg(1, "...and adding to erasable_list\n"); 711 list_add_tail(&jeb->list, &c->erasable_list); 712 } 713 } 714 jffs2_dbg(1, "Done OK\n"); 715 } else if (jeb == c->gcblock) { 716 jffs2_dbg(2, "Not moving gcblock 0x%08x to dirty_list\n", 717 jeb->offset); 718 } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) { 719 jffs2_dbg(1, "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", 720 jeb->offset); 721 list_del(&jeb->list); 722 jffs2_dbg(1, "...and adding to dirty_list\n"); 723 list_add_tail(&jeb->list, &c->dirty_list); 724 } else if (VERYDIRTY(c, jeb->dirty_size) && 725 !VERYDIRTY(c, jeb->dirty_size - addedsize)) { 726 jffs2_dbg(1, "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", 727 jeb->offset); 728 list_del(&jeb->list); 729 jffs2_dbg(1, "...and adding to very_dirty_list\n"); 730 list_add_tail(&jeb->list, &c->very_dirty_list); 731 } else { 732 jffs2_dbg(1, "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n", 733 jeb->offset, jeb->free_size, jeb->dirty_size, 734 jeb->used_size); 735 } 736 737 spin_unlock(&c->erase_completion_lock); 738 739 if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) || 740 (c->flags & JFFS2_SB_FLAG_BUILDING)) { 741 /* We didn't lock the erase_free_sem */ 742 return; 743 } 744 745 /* The erase_free_sem is locked, and has been since before we marked the node obsolete 746 and potentially put its eraseblock onto the erase_pending_list. Thus, we know that 747 the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet 748 by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */ 749 750 jffs2_dbg(1, "obliterating obsoleted node at 0x%08x\n", 751 ref_offset(ref)); 752 ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n); 753 if (ret) { 754 pr_warn("Read error reading from obsoleted node at 0x%08x: %d\n", 755 ref_offset(ref), ret); 756 goto out_erase_sem; 757 } 758 if (retlen != sizeof(n)) { 759 pr_warn("Short read from obsoleted node at 0x%08x: %zd\n", 760 ref_offset(ref), retlen); 761 goto out_erase_sem; 762 } 763 if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) { 764 pr_warn("Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", 765 je32_to_cpu(n.totlen), freed_len); 766 goto out_erase_sem; 767 } 768 if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) { 769 jffs2_dbg(1, "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", 770 ref_offset(ref), je16_to_cpu(n.nodetype)); 771 goto out_erase_sem; 772 } 773 /* XXX FIXME: This is ugly now */ 774 n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE); 775 ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n); 776 if (ret) { 777 pr_warn("Write error in obliterating obsoleted node at 0x%08x: %d\n", 778 ref_offset(ref), ret); 779 goto out_erase_sem; 780 } 781 if (retlen != sizeof(n)) { 782 pr_warn("Short write in obliterating obsoleted node at 0x%08x: %zd\n", 783 ref_offset(ref), retlen); 784 goto out_erase_sem; 785 } 786 787 /* Nodes which have been marked obsolete no longer need to be 788 associated with any inode. Remove them from the per-inode list. 789 790 Note we can't do this for NAND at the moment because we need 791 obsolete dirent nodes to stay on the lists, because of the 792 horridness in jffs2_garbage_collect_deletion_dirent(). Also 793 because we delete the inocache, and on NAND we need that to 794 stay around until all the nodes are actually erased, in order 795 to stop us from giving the same inode number to another newly 796 created inode. */ 797 if (ref->next_in_ino) { 798 struct jffs2_inode_cache *ic; 799 struct jffs2_raw_node_ref **p; 800 801 spin_lock(&c->erase_completion_lock); 802 803 ic = jffs2_raw_ref_to_ic(ref); 804 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino)) 805 ; 806 807 *p = ref->next_in_ino; 808 ref->next_in_ino = NULL; 809 810 switch (ic->class) { 811 #ifdef CONFIG_JFFS2_FS_XATTR 812 case RAWNODE_CLASS_XATTR_DATUM: 813 jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic); 814 break; 815 case RAWNODE_CLASS_XATTR_REF: 816 jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic); 817 break; 818 #endif 819 default: 820 if (ic->nodes == (void *)ic && ic->pino_nlink == 0) 821 jffs2_del_ino_cache(c, ic); 822 break; 823 } 824 spin_unlock(&c->erase_completion_lock); 825 } 826 827 out_erase_sem: 828 mutex_unlock(&c->erase_free_sem); 829 } 830 831 int jffs2_thread_should_wake(struct jffs2_sb_info *c) 832 { 833 int ret = 0; 834 uint32_t dirty; 835 int nr_very_dirty = 0; 836 struct jffs2_eraseblock *jeb; 837 838 if (!list_empty(&c->erase_complete_list) || 839 !list_empty(&c->erase_pending_list)) 840 return 1; 841 842 if (c->unchecked_size) { 843 jffs2_dbg(1, "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n", 844 c->unchecked_size, c->checked_ino); 845 return 1; 846 } 847 848 /* dirty_size contains blocks on erase_pending_list 849 * those blocks are counted in c->nr_erasing_blocks. 850 * If one block is actually erased, it is not longer counted as dirty_space 851 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it 852 * with c->nr_erasing_blocks * c->sector_size again. 853 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks 854 * This helps us to force gc and pick eventually a clean block to spread the load. 855 */ 856 dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size; 857 858 if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger && 859 (dirty > c->nospc_dirty_size)) 860 ret = 1; 861 862 list_for_each_entry(jeb, &c->very_dirty_list, list) { 863 nr_very_dirty++; 864 if (nr_very_dirty == c->vdirty_blocks_gctrigger) { 865 ret = 1; 866 /* In debug mode, actually go through and count them all */ 867 D1(continue); 868 break; 869 } 870 } 871 872 jffs2_dbg(1, "%s(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n", 873 __func__, c->nr_free_blocks, c->nr_erasing_blocks, 874 c->dirty_size, nr_very_dirty, ret ? "yes" : "no"); 875 876 return ret; 877 } 878