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 if (ret) 421 return ret; 422 /* Just lock it again and continue. Nothing much can change because 423 we hold c->alloc_sem anyway. In fact, it's not entirely clear why 424 we hold c->erase_completion_lock in the majority of this function... 425 but that's a question for another (more caffeine-rich) day. */ 426 spin_lock(&c->erase_completion_lock); 427 428 waste = jeb->free_size; 429 jffs2_link_node_ref(c, jeb, 430 (jeb->offset + c->sector_size - waste) | REF_OBSOLETE, 431 waste, NULL); 432 /* FIXME: that made it count as dirty. Convert to wasted */ 433 jeb->dirty_size -= waste; 434 c->dirty_size -= waste; 435 jeb->wasted_size += waste; 436 c->wasted_size += waste; 437 438 jffs2_close_nextblock(c, jeb); 439 jeb = NULL; 440 } 441 } 442 443 if (!jeb) { 444 445 ret = jffs2_find_nextblock(c); 446 if (ret) 447 return ret; 448 449 jeb = c->nextblock; 450 451 if (jeb->free_size != c->sector_size - c->cleanmarker_size) { 452 pr_warn("Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", 453 jeb->offset, jeb->free_size); 454 goto restart; 455 } 456 } 457 /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has 458 enough space */ 459 *len = jeb->free_size - reserved_size; 460 461 if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size && 462 !jeb->first_node->next_in_ino) { 463 /* Only node in it beforehand was a CLEANMARKER node (we think). 464 So mark it obsolete now that there's going to be another node 465 in the block. This will reduce used_size to zero but We've 466 already set c->nextblock so that jffs2_mark_node_obsolete() 467 won't try to refile it to the dirty_list. 468 */ 469 spin_unlock(&c->erase_completion_lock); 470 jffs2_mark_node_obsolete(c, jeb->first_node); 471 spin_lock(&c->erase_completion_lock); 472 } 473 474 jffs2_dbg(1, "%s(): Giving 0x%x bytes at 0x%x\n", 475 __func__, 476 *len, jeb->offset + (c->sector_size - jeb->free_size)); 477 return 0; 478 } 479 480 /** 481 * jffs2_add_physical_node_ref - add a physical node reference to the list 482 * @c: superblock info 483 * @new: new node reference to add 484 * @len: length of this physical node 485 * 486 * Should only be used to report nodes for which space has been allocated 487 * by jffs2_reserve_space. 488 * 489 * Must be called with the alloc_sem held. 490 */ 491 492 struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c, 493 uint32_t ofs, uint32_t len, 494 struct jffs2_inode_cache *ic) 495 { 496 struct jffs2_eraseblock *jeb; 497 struct jffs2_raw_node_ref *new; 498 499 jeb = &c->blocks[ofs / c->sector_size]; 500 501 jffs2_dbg(1, "%s(): Node at 0x%x(%d), size 0x%x\n", 502 __func__, ofs & ~3, ofs & 3, len); 503 #if 1 504 /* Allow non-obsolete nodes only to be added at the end of c->nextblock, 505 if c->nextblock is set. Note that wbuf.c will file obsolete nodes 506 even after refiling c->nextblock */ 507 if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE)) 508 && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) { 509 pr_warn("argh. node added in wrong place at 0x%08x(%d)\n", 510 ofs & ~3, ofs & 3); 511 if (c->nextblock) 512 pr_warn("nextblock 0x%08x", c->nextblock->offset); 513 else 514 pr_warn("No nextblock"); 515 pr_cont(", expected at %08x\n", 516 jeb->offset + (c->sector_size - jeb->free_size)); 517 return ERR_PTR(-EINVAL); 518 } 519 #endif 520 spin_lock(&c->erase_completion_lock); 521 522 new = jffs2_link_node_ref(c, jeb, ofs, len, ic); 523 524 if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) { 525 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */ 526 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n", 527 jeb->offset, jeb->free_size, jeb->dirty_size, 528 jeb->used_size); 529 if (jffs2_wbuf_dirty(c)) { 530 /* Flush the last write in the block if it's outstanding */ 531 spin_unlock(&c->erase_completion_lock); 532 jffs2_flush_wbuf_pad(c); 533 spin_lock(&c->erase_completion_lock); 534 } 535 536 list_add_tail(&jeb->list, &c->clean_list); 537 c->nextblock = NULL; 538 } 539 jffs2_dbg_acct_sanity_check_nolock(c,jeb); 540 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 541 542 spin_unlock(&c->erase_completion_lock); 543 544 return new; 545 } 546 547 548 void jffs2_complete_reservation(struct jffs2_sb_info *c) 549 { 550 jffs2_dbg(1, "jffs2_complete_reservation()\n"); 551 spin_lock(&c->erase_completion_lock); 552 jffs2_garbage_collect_trigger(c); 553 spin_unlock(&c->erase_completion_lock); 554 mutex_unlock(&c->alloc_sem); 555 } 556 557 static inline int on_list(struct list_head *obj, struct list_head *head) 558 { 559 struct list_head *this; 560 561 list_for_each(this, head) { 562 if (this == obj) { 563 jffs2_dbg(1, "%p is on list at %p\n", obj, head); 564 return 1; 565 566 } 567 } 568 return 0; 569 } 570 571 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref) 572 { 573 struct jffs2_eraseblock *jeb; 574 int blocknr; 575 struct jffs2_unknown_node n; 576 int ret, addedsize; 577 size_t retlen; 578 uint32_t freed_len; 579 580 if(unlikely(!ref)) { 581 pr_notice("EEEEEK. jffs2_mark_node_obsolete called with NULL node\n"); 582 return; 583 } 584 if (ref_obsolete(ref)) { 585 jffs2_dbg(1, "%s(): called with already obsolete node at 0x%08x\n", 586 __func__, ref_offset(ref)); 587 return; 588 } 589 blocknr = ref->flash_offset / c->sector_size; 590 if (blocknr >= c->nr_blocks) { 591 pr_notice("raw node at 0x%08x is off the end of device!\n", 592 ref->flash_offset); 593 BUG(); 594 } 595 jeb = &c->blocks[blocknr]; 596 597 if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) && 598 !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) { 599 /* Hm. This may confuse static lock analysis. If any of the above 600 three conditions is false, we're going to return from this 601 function without actually obliterating any nodes or freeing 602 any jffs2_raw_node_refs. So we don't need to stop erases from 603 happening, or protect against people holding an obsolete 604 jffs2_raw_node_ref without the erase_completion_lock. */ 605 mutex_lock(&c->erase_free_sem); 606 } 607 608 spin_lock(&c->erase_completion_lock); 609 610 freed_len = ref_totlen(c, jeb, ref); 611 612 if (ref_flags(ref) == REF_UNCHECKED) { 613 D1(if (unlikely(jeb->unchecked_size < freed_len)) { 614 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", 615 freed_len, blocknr, 616 ref->flash_offset, jeb->used_size); 617 BUG(); 618 }) 619 jffs2_dbg(1, "Obsoleting previously unchecked node at 0x%08x of len %x\n", 620 ref_offset(ref), freed_len); 621 jeb->unchecked_size -= freed_len; 622 c->unchecked_size -= freed_len; 623 } else { 624 D1(if (unlikely(jeb->used_size < freed_len)) { 625 pr_notice("raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n", 626 freed_len, blocknr, 627 ref->flash_offset, jeb->used_size); 628 BUG(); 629 }) 630 jffs2_dbg(1, "Obsoleting node at 0x%08x of len %#x: ", 631 ref_offset(ref), freed_len); 632 jeb->used_size -= freed_len; 633 c->used_size -= freed_len; 634 } 635 636 // Take care, that wasted size is taken into concern 637 if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) { 638 jffs2_dbg(1, "Dirtying\n"); 639 addedsize = freed_len; 640 jeb->dirty_size += freed_len; 641 c->dirty_size += freed_len; 642 643 /* Convert wasted space to dirty, if not a bad block */ 644 if (jeb->wasted_size) { 645 if (on_list(&jeb->list, &c->bad_used_list)) { 646 jffs2_dbg(1, "Leaving block at %08x on the bad_used_list\n", 647 jeb->offset); 648 addedsize = 0; /* To fool the refiling code later */ 649 } else { 650 jffs2_dbg(1, "Converting %d bytes of wasted space to dirty in block at %08x\n", 651 jeb->wasted_size, jeb->offset); 652 addedsize += jeb->wasted_size; 653 jeb->dirty_size += jeb->wasted_size; 654 c->dirty_size += jeb->wasted_size; 655 c->wasted_size -= jeb->wasted_size; 656 jeb->wasted_size = 0; 657 } 658 } 659 } else { 660 jffs2_dbg(1, "Wasting\n"); 661 addedsize = 0; 662 jeb->wasted_size += freed_len; 663 c->wasted_size += freed_len; 664 } 665 ref->flash_offset = ref_offset(ref) | REF_OBSOLETE; 666 667 jffs2_dbg_acct_sanity_check_nolock(c, jeb); 668 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 669 670 if (c->flags & JFFS2_SB_FLAG_SCANNING) { 671 /* Flash scanning is in progress. Don't muck about with the block 672 lists because they're not ready yet, and don't actually 673 obliterate nodes that look obsolete. If they weren't 674 marked obsolete on the flash at the time they _became_ 675 obsolete, there was probably a reason for that. */ 676 spin_unlock(&c->erase_completion_lock); 677 /* We didn't lock the erase_free_sem */ 678 return; 679 } 680 681 if (jeb == c->nextblock) { 682 jffs2_dbg(2, "Not moving nextblock 0x%08x to dirty/erase_pending list\n", 683 jeb->offset); 684 } else if (!jeb->used_size && !jeb->unchecked_size) { 685 if (jeb == c->gcblock) { 686 jffs2_dbg(1, "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", 687 jeb->offset); 688 c->gcblock = NULL; 689 } else { 690 jffs2_dbg(1, "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", 691 jeb->offset); 692 list_del(&jeb->list); 693 } 694 if (jffs2_wbuf_dirty(c)) { 695 jffs2_dbg(1, "...and adding to erasable_pending_wbuf_list\n"); 696 list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list); 697 } else { 698 if (jiffies & 127) { 699 /* Most of the time, we just erase it immediately. Otherwise we 700 spend ages scanning it on mount, etc. */ 701 jffs2_dbg(1, "...and adding to erase_pending_list\n"); 702 list_add_tail(&jeb->list, &c->erase_pending_list); 703 c->nr_erasing_blocks++; 704 jffs2_garbage_collect_trigger(c); 705 } else { 706 /* Sometimes, however, we leave it elsewhere so it doesn't get 707 immediately reused, and we spread the load a bit. */ 708 jffs2_dbg(1, "...and adding to erasable_list\n"); 709 list_add_tail(&jeb->list, &c->erasable_list); 710 } 711 } 712 jffs2_dbg(1, "Done OK\n"); 713 } else if (jeb == c->gcblock) { 714 jffs2_dbg(2, "Not moving gcblock 0x%08x to dirty_list\n", 715 jeb->offset); 716 } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) { 717 jffs2_dbg(1, "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", 718 jeb->offset); 719 list_del(&jeb->list); 720 jffs2_dbg(1, "...and adding to dirty_list\n"); 721 list_add_tail(&jeb->list, &c->dirty_list); 722 } else if (VERYDIRTY(c, jeb->dirty_size) && 723 !VERYDIRTY(c, jeb->dirty_size - addedsize)) { 724 jffs2_dbg(1, "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", 725 jeb->offset); 726 list_del(&jeb->list); 727 jffs2_dbg(1, "...and adding to very_dirty_list\n"); 728 list_add_tail(&jeb->list, &c->very_dirty_list); 729 } else { 730 jffs2_dbg(1, "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n", 731 jeb->offset, jeb->free_size, jeb->dirty_size, 732 jeb->used_size); 733 } 734 735 spin_unlock(&c->erase_completion_lock); 736 737 if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) || 738 (c->flags & JFFS2_SB_FLAG_BUILDING)) { 739 /* We didn't lock the erase_free_sem */ 740 return; 741 } 742 743 /* The erase_free_sem is locked, and has been since before we marked the node obsolete 744 and potentially put its eraseblock onto the erase_pending_list. Thus, we know that 745 the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet 746 by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */ 747 748 jffs2_dbg(1, "obliterating obsoleted node at 0x%08x\n", 749 ref_offset(ref)); 750 ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n); 751 if (ret) { 752 pr_warn("Read error reading from obsoleted node at 0x%08x: %d\n", 753 ref_offset(ref), ret); 754 goto out_erase_sem; 755 } 756 if (retlen != sizeof(n)) { 757 pr_warn("Short read from obsoleted node at 0x%08x: %zd\n", 758 ref_offset(ref), retlen); 759 goto out_erase_sem; 760 } 761 if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) { 762 pr_warn("Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", 763 je32_to_cpu(n.totlen), freed_len); 764 goto out_erase_sem; 765 } 766 if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) { 767 jffs2_dbg(1, "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", 768 ref_offset(ref), je16_to_cpu(n.nodetype)); 769 goto out_erase_sem; 770 } 771 /* XXX FIXME: This is ugly now */ 772 n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE); 773 ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n); 774 if (ret) { 775 pr_warn("Write error in obliterating obsoleted node at 0x%08x: %d\n", 776 ref_offset(ref), ret); 777 goto out_erase_sem; 778 } 779 if (retlen != sizeof(n)) { 780 pr_warn("Short write in obliterating obsoleted node at 0x%08x: %zd\n", 781 ref_offset(ref), retlen); 782 goto out_erase_sem; 783 } 784 785 /* Nodes which have been marked obsolete no longer need to be 786 associated with any inode. Remove them from the per-inode list. 787 788 Note we can't do this for NAND at the moment because we need 789 obsolete dirent nodes to stay on the lists, because of the 790 horridness in jffs2_garbage_collect_deletion_dirent(). Also 791 because we delete the inocache, and on NAND we need that to 792 stay around until all the nodes are actually erased, in order 793 to stop us from giving the same inode number to another newly 794 created inode. */ 795 if (ref->next_in_ino) { 796 struct jffs2_inode_cache *ic; 797 struct jffs2_raw_node_ref **p; 798 799 spin_lock(&c->erase_completion_lock); 800 801 ic = jffs2_raw_ref_to_ic(ref); 802 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino)) 803 ; 804 805 *p = ref->next_in_ino; 806 ref->next_in_ino = NULL; 807 808 switch (ic->class) { 809 #ifdef CONFIG_JFFS2_FS_XATTR 810 case RAWNODE_CLASS_XATTR_DATUM: 811 jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic); 812 break; 813 case RAWNODE_CLASS_XATTR_REF: 814 jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic); 815 break; 816 #endif 817 default: 818 if (ic->nodes == (void *)ic && ic->pino_nlink == 0) 819 jffs2_del_ino_cache(c, ic); 820 break; 821 } 822 spin_unlock(&c->erase_completion_lock); 823 } 824 825 out_erase_sem: 826 mutex_unlock(&c->erase_free_sem); 827 } 828 829 int jffs2_thread_should_wake(struct jffs2_sb_info *c) 830 { 831 int ret = 0; 832 uint32_t dirty; 833 int nr_very_dirty = 0; 834 struct jffs2_eraseblock *jeb; 835 836 if (!list_empty(&c->erase_complete_list) || 837 !list_empty(&c->erase_pending_list)) 838 return 1; 839 840 if (c->unchecked_size) { 841 jffs2_dbg(1, "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n", 842 c->unchecked_size, c->checked_ino); 843 return 1; 844 } 845 846 /* dirty_size contains blocks on erase_pending_list 847 * those blocks are counted in c->nr_erasing_blocks. 848 * If one block is actually erased, it is not longer counted as dirty_space 849 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it 850 * with c->nr_erasing_blocks * c->sector_size again. 851 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks 852 * This helps us to force gc and pick eventually a clean block to spread the load. 853 */ 854 dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size; 855 856 if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger && 857 (dirty > c->nospc_dirty_size)) 858 ret = 1; 859 860 list_for_each_entry(jeb, &c->very_dirty_list, list) { 861 nr_very_dirty++; 862 if (nr_very_dirty == c->vdirty_blocks_gctrigger) { 863 ret = 1; 864 /* In debug mode, actually go through and count them all */ 865 D1(continue); 866 break; 867 } 868 } 869 870 jffs2_dbg(1, "%s(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n", 871 __func__, c->nr_free_blocks, c->nr_erasing_blocks, 872 c->dirty_size, nr_very_dirty, ret ? "yes" : "no"); 873 874 return ret; 875 } 876