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/signal.h> 18#include "nodelist.h" 19#include "debug.h" 20 21/* 22 * Check whether the user is allowed to write. 23 */ 24static 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 71static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, 72 uint32_t *len, uint32_t sumsize); 73 74int 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 remove_wait_queue(&c->erase_wait, &wait); 183 } else 184 spin_unlock(&c->erase_completion_lock); 185 } else if (ret) 186 return ret; 187 188 cond_resched(); 189 190 if (signal_pending(current)) 191 return -EINTR; 192 193 mutex_lock(&c->alloc_sem); 194 spin_lock(&c->erase_completion_lock); 195 } 196 197 ret = jffs2_do_reserve_space(c, minsize, len, sumsize); 198 if (ret) { 199 jffs2_dbg(1, "%s(): ret is %d\n", __func__, ret); 200 } 201 } 202 203out: 204 spin_unlock(&c->erase_completion_lock); 205 if (!ret) 206 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 207 if (ret) 208 mutex_unlock(&c->alloc_sem); 209 return ret; 210} 211 212int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize, 213 uint32_t *len, uint32_t sumsize) 214{ 215 int ret; 216 minsize = PAD(minsize); 217 218 jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize); 219 220 while (true) { 221 spin_lock(&c->erase_completion_lock); 222 ret = jffs2_do_reserve_space(c, minsize, len, sumsize); 223 if (ret) { 224 jffs2_dbg(1, "%s(): looping, ret is %d\n", 225 __func__, ret); 226 } 227 spin_unlock(&c->erase_completion_lock); 228 229 if (ret == -EAGAIN) 230 cond_resched(); 231 else 232 break; 233 } 234 if (!ret) 235 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); 236 237 return ret; 238} 239 240 241/* Classify nextblock (clean, dirty of verydirty) and force to select an other one */ 242 243static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) 244{ 245 246 if (c->nextblock == NULL) { 247 jffs2_dbg(1, "%s(): Erase block at 0x%08x has already been placed in a list\n", 248 __func__, jeb->offset); 249 return; 250 } 251 /* Check, if we have a dirty block now, or if it was dirty already */ 252 if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) { 253 c->dirty_size += jeb->wasted_size; 254 c->wasted_size -= jeb->wasted_size; 255 jeb->dirty_size += jeb->wasted_size; 256 jeb->wasted_size = 0; 257 if (VERYDIRTY(c, jeb->dirty_size)) { 258 jffs2_dbg(1, "Adding full erase block at 0x%08x to very_dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n", 259 jeb->offset, jeb->free_size, jeb->dirty_size, 260 jeb->used_size); 261 list_add_tail(&jeb->list, &c->very_dirty_list); 262 } else { 263 jffs2_dbg(1, "Adding full erase block at 0x%08x to dirty_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->dirty_list); 267 } 268 } else { 269 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n", 270 jeb->offset, jeb->free_size, jeb->dirty_size, 271 jeb->used_size); 272 list_add_tail(&jeb->list, &c->clean_list); 273 } 274 c->nextblock = NULL; 275 276} 277 278/* Select a new jeb for nextblock */ 279 280static int jffs2_find_nextblock(struct jffs2_sb_info *c) 281{ 282 struct list_head *next; 283 284 /* Take the next block off the 'free' list */ 285 286 if (list_empty(&c->free_list)) { 287 288 if (!c->nr_erasing_blocks && 289 !list_empty(&c->erasable_list)) { 290 struct jffs2_eraseblock *ejeb; 291 292 ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list); 293 list_move_tail(&ejeb->list, &c->erase_pending_list); 294 c->nr_erasing_blocks++; 295 jffs2_garbage_collect_trigger(c); 296 jffs2_dbg(1, "%s(): Triggering erase of erasable block at 0x%08x\n", 297 __func__, ejeb->offset); 298 } 299 300 if (!c->nr_erasing_blocks && 301 !list_empty(&c->erasable_pending_wbuf_list)) { 302 jffs2_dbg(1, "%s(): Flushing write buffer\n", 303 __func__); 304 /* c->nextblock is NULL, no update to c->nextblock allowed */ 305 spin_unlock(&c->erase_completion_lock); 306 jffs2_flush_wbuf_pad(c); 307 spin_lock(&c->erase_completion_lock); 308 /* Have another go. It'll be on the erasable_list now */ 309 return -EAGAIN; 310 } 311 312 if (!c->nr_erasing_blocks) { 313 /* Ouch. We're in GC, or we wouldn't have got here. 314 And there's no space left. At all. */ 315 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", 316 c->nr_erasing_blocks, c->nr_free_blocks, 317 list_empty(&c->erasable_list) ? "yes" : "no", 318 list_empty(&c->erasing_list) ? "yes" : "no", 319 list_empty(&c->erase_pending_list) ? "yes" : "no"); 320 return -ENOSPC; 321 } 322 323 spin_unlock(&c->erase_completion_lock); 324 /* Don't wait for it; just erase one right now */ 325 jffs2_erase_pending_blocks(c, 1); 326 spin_lock(&c->erase_completion_lock); 327 328 /* An erase may have failed, decreasing the 329 amount of free space available. So we must 330 restart from the beginning */ 331 return -EAGAIN; 332 } 333 334 next = c->free_list.next; 335 list_del(next); 336 c->nextblock = list_entry(next, struct jffs2_eraseblock, list); 337 c->nr_free_blocks--; 338 339 jffs2_sum_reset_collected(c->summary); /* reset collected summary */ 340 341#ifdef CONFIG_JFFS2_FS_WRITEBUFFER 342 /* adjust write buffer offset, else we get a non contiguous write bug */ 343 if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len) 344 c->wbuf_ofs = 0xffffffff; 345#endif 346 347 jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n", 348 __func__, c->nextblock->offset); 349 350 return 0; 351} 352 353/* Called with alloc sem _and_ erase_completion_lock */ 354static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, 355 uint32_t *len, uint32_t sumsize) 356{ 357 struct jffs2_eraseblock *jeb = c->nextblock; 358 uint32_t reserved_size; /* for summary information at the end of the jeb */ 359 int ret; 360 361 restart: 362 reserved_size = 0; 363 364 if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) { 365 /* NOSUM_SIZE means not to generate summary */ 366 367 if (jeb) { 368 reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE); 369 dbg_summary("minsize=%d , jeb->free=%d ," 370 "summary->size=%d , sumsize=%d\n", 371 minsize, jeb->free_size, 372 c->summary->sum_size, sumsize); 373 } 374 375 /* Is there enough space for writing out the current node, or we have to 376 write out summary information now, close this jeb and select new nextblock? */ 377 if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize + 378 JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) { 379 380 /* Has summary been disabled for this jeb? */ 381 if (jffs2_sum_is_disabled(c->summary)) { 382 sumsize = JFFS2_SUMMARY_NOSUM_SIZE; 383 goto restart; 384 } 385 386 /* Writing out the collected summary information */ 387 dbg_summary("generating summary for 0x%08x.\n", jeb->offset); 388 ret = jffs2_sum_write_sumnode(c); 389 390 if (ret) 391 return ret; 392 393 if (jffs2_sum_is_disabled(c->summary)) { 394 /* jffs2_write_sumnode() couldn't write out the summary information 395 diabling summary for this jeb and free the collected information 396 */ 397 sumsize = JFFS2_SUMMARY_NOSUM_SIZE; 398 goto restart; 399 } 400 401 jffs2_close_nextblock(c, jeb); 402 jeb = NULL; 403 /* keep always valid value in reserved_size */ 404 reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE); 405 } 406 } else { 407 if (jeb && minsize > jeb->free_size) { 408 uint32_t waste; 409 410 /* Skip the end of this block and file it as having some dirty space */ 411 /* If there's a pending write to it, flush now */ 412 413 if (jffs2_wbuf_dirty(c)) { 414 spin_unlock(&c->erase_completion_lock); 415 jffs2_dbg(1, "%s(): Flushing write buffer\n", 416 __func__); 417 jffs2_flush_wbuf_pad(c); 418 spin_lock(&c->erase_completion_lock); 419 jeb = c->nextblock; 420 goto restart; 421 } 422 423 spin_unlock(&c->erase_completion_lock); 424 425 ret = jffs2_prealloc_raw_node_refs(c, jeb, 1); 426 427 /* Just lock it again and continue. Nothing much can change because 428 we hold c->alloc_sem anyway. In fact, it's not entirely clear why 429 we hold c->erase_completion_lock in the majority of this function... 430 but that's a question for another (more caffeine-rich) day. */ 431 spin_lock(&c->erase_completion_lock); 432 433 if (ret) 434 return ret; 435 436 waste = jeb->free_size; 437 jffs2_link_node_ref(c, jeb, 438 (jeb->offset + c->sector_size - waste) | REF_OBSOLETE, 439 waste, NULL); 440 /* FIXME: that made it count as dirty. Convert to wasted */ 441 jeb->dirty_size -= waste; 442 c->dirty_size -= waste; 443 jeb->wasted_size += waste; 444 c->wasted_size += waste; 445 446 jffs2_close_nextblock(c, jeb); 447 jeb = NULL; 448 } 449 } 450 451 if (!jeb) { 452 453 ret = jffs2_find_nextblock(c); 454 if (ret) 455 return ret; 456 457 jeb = c->nextblock; 458 459 if (jeb->free_size != c->sector_size - c->cleanmarker_size) { 460 pr_warn("Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", 461 jeb->offset, jeb->free_size); 462 goto restart; 463 } 464 } 465 /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has 466 enough space */ 467 *len = jeb->free_size - reserved_size; 468 469 if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size && 470 !jeb->first_node->next_in_ino) { 471 /* Only node in it beforehand was a CLEANMARKER node (we think). 472 So mark it obsolete now that there's going to be another node 473 in the block. This will reduce used_size to zero but We've 474 already set c->nextblock so that jffs2_mark_node_obsolete() 475 won't try to refile it to the dirty_list. 476 */ 477 spin_unlock(&c->erase_completion_lock); 478 jffs2_mark_node_obsolete(c, jeb->first_node); 479 spin_lock(&c->erase_completion_lock); 480 } 481 482 jffs2_dbg(1, "%s(): Giving 0x%x bytes at 0x%x\n", 483 __func__, 484 *len, jeb->offset + (c->sector_size - jeb->free_size)); 485 return 0; 486} 487 488/** 489 * jffs2_add_physical_node_ref - add a physical node reference to the list 490 * @c: superblock info 491 * @new: new node reference to add 492 * @len: length of this physical node 493 * 494 * Should only be used to report nodes for which space has been allocated 495 * by jffs2_reserve_space. 496 * 497 * Must be called with the alloc_sem held. 498 */ 499 500struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c, 501 uint32_t ofs, uint32_t len, 502 struct jffs2_inode_cache *ic) 503{ 504 struct jffs2_eraseblock *jeb; 505 struct jffs2_raw_node_ref *new; 506 507 jeb = &c->blocks[ofs / c->sector_size]; 508 509 jffs2_dbg(1, "%s(): Node at 0x%x(%d), size 0x%x\n", 510 __func__, ofs & ~3, ofs & 3, len); 511#if 1 512 /* Allow non-obsolete nodes only to be added at the end of c->nextblock, 513 if c->nextblock is set. Note that wbuf.c will file obsolete nodes 514 even after refiling c->nextblock */ 515 if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE)) 516 && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) { 517 pr_warn("argh. node added in wrong place at 0x%08x(%d)\n", 518 ofs & ~3, ofs & 3); 519 if (c->nextblock) 520 pr_warn("nextblock 0x%08x", c->nextblock->offset); 521 else 522 pr_warn("No nextblock"); 523 pr_cont(", expected at %08x\n", 524 jeb->offset + (c->sector_size - jeb->free_size)); 525 return ERR_PTR(-EINVAL); 526 } 527#endif 528 spin_lock(&c->erase_completion_lock); 529 530 new = jffs2_link_node_ref(c, jeb, ofs, len, ic); 531 532 if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) { 533 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */ 534 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n", 535 jeb->offset, jeb->free_size, jeb->dirty_size, 536 jeb->used_size); 537 if (jffs2_wbuf_dirty(c)) { 538 /* Flush the last write in the block if it's outstanding */ 539 spin_unlock(&c->erase_completion_lock); 540 jffs2_flush_wbuf_pad(c); 541 spin_lock(&c->erase_completion_lock); 542 } 543 544 list_add_tail(&jeb->list, &c->clean_list); 545 c->nextblock = NULL; 546 } 547 jffs2_dbg_acct_sanity_check_nolock(c,jeb); 548 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 549 550 spin_unlock(&c->erase_completion_lock); 551 552 return new; 553} 554 555 556void jffs2_complete_reservation(struct jffs2_sb_info *c) 557{ 558 jffs2_dbg(1, "jffs2_complete_reservation()\n"); 559 spin_lock(&c->erase_completion_lock); 560 jffs2_garbage_collect_trigger(c); 561 spin_unlock(&c->erase_completion_lock); 562 mutex_unlock(&c->alloc_sem); 563} 564 565static inline int on_list(struct list_head *obj, struct list_head *head) 566{ 567 struct list_head *this; 568 569 list_for_each(this, head) { 570 if (this == obj) { 571 jffs2_dbg(1, "%p is on list at %p\n", obj, head); 572 return 1; 573 574 } 575 } 576 return 0; 577} 578 579void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref) 580{ 581 struct jffs2_eraseblock *jeb; 582 int blocknr; 583 struct jffs2_unknown_node n; 584 int ret, addedsize; 585 size_t retlen; 586 uint32_t freed_len; 587 588 if(unlikely(!ref)) { 589 pr_notice("EEEEEK. jffs2_mark_node_obsolete called with NULL node\n"); 590 return; 591 } 592 if (ref_obsolete(ref)) { 593 jffs2_dbg(1, "%s(): called with already obsolete node at 0x%08x\n", 594 __func__, ref_offset(ref)); 595 return; 596 } 597 blocknr = ref->flash_offset / c->sector_size; 598 if (blocknr >= c->nr_blocks) { 599 pr_notice("raw node at 0x%08x is off the end of device!\n", 600 ref->flash_offset); 601 BUG(); 602 } 603 jeb = &c->blocks[blocknr]; 604 605 if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) && 606 !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) { 607 /* Hm. This may confuse static lock analysis. If any of the above 608 three conditions is false, we're going to return from this 609 function without actually obliterating any nodes or freeing 610 any jffs2_raw_node_refs. So we don't need to stop erases from 611 happening, or protect against people holding an obsolete 612 jffs2_raw_node_ref without the erase_completion_lock. */ 613 mutex_lock(&c->erase_free_sem); 614 } 615 616 spin_lock(&c->erase_completion_lock); 617 618 freed_len = ref_totlen(c, jeb, ref); 619 620 if (ref_flags(ref) == REF_UNCHECKED) { 621 D1(if (unlikely(jeb->unchecked_size < freed_len)) { 622 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", 623 freed_len, blocknr, 624 ref->flash_offset, jeb->used_size); 625 BUG(); 626 }) 627 jffs2_dbg(1, "Obsoleting previously unchecked node at 0x%08x of len %x\n", 628 ref_offset(ref), freed_len); 629 jeb->unchecked_size -= freed_len; 630 c->unchecked_size -= freed_len; 631 } else { 632 D1(if (unlikely(jeb->used_size < freed_len)) { 633 pr_notice("raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n", 634 freed_len, blocknr, 635 ref->flash_offset, jeb->used_size); 636 BUG(); 637 }) 638 jffs2_dbg(1, "Obsoleting node at 0x%08x of len %#x: ", 639 ref_offset(ref), freed_len); 640 jeb->used_size -= freed_len; 641 c->used_size -= freed_len; 642 } 643 644 // Take care, that wasted size is taken into concern 645 if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) { 646 jffs2_dbg(1, "Dirtying\n"); 647 addedsize = freed_len; 648 jeb->dirty_size += freed_len; 649 c->dirty_size += freed_len; 650 651 /* Convert wasted space to dirty, if not a bad block */ 652 if (jeb->wasted_size) { 653 if (on_list(&jeb->list, &c->bad_used_list)) { 654 jffs2_dbg(1, "Leaving block at %08x on the bad_used_list\n", 655 jeb->offset); 656 addedsize = 0; /* To fool the refiling code later */ 657 } else { 658 jffs2_dbg(1, "Converting %d bytes of wasted space to dirty in block at %08x\n", 659 jeb->wasted_size, jeb->offset); 660 addedsize += jeb->wasted_size; 661 jeb->dirty_size += jeb->wasted_size; 662 c->dirty_size += jeb->wasted_size; 663 c->wasted_size -= jeb->wasted_size; 664 jeb->wasted_size = 0; 665 } 666 } 667 } else { 668 jffs2_dbg(1, "Wasting\n"); 669 addedsize = 0; 670 jeb->wasted_size += freed_len; 671 c->wasted_size += freed_len; 672 } 673 ref->flash_offset = ref_offset(ref) | REF_OBSOLETE; 674 675 jffs2_dbg_acct_sanity_check_nolock(c, jeb); 676 jffs2_dbg_acct_paranoia_check_nolock(c, jeb); 677 678 if (c->flags & JFFS2_SB_FLAG_SCANNING) { 679 /* Flash scanning is in progress. Don't muck about with the block 680 lists because they're not ready yet, and don't actually 681 obliterate nodes that look obsolete. If they weren't 682 marked obsolete on the flash at the time they _became_ 683 obsolete, there was probably a reason for that. */ 684 spin_unlock(&c->erase_completion_lock); 685 /* We didn't lock the erase_free_sem */ 686 return; 687 } 688 689 if (jeb == c->nextblock) { 690 jffs2_dbg(2, "Not moving nextblock 0x%08x to dirty/erase_pending list\n", 691 jeb->offset); 692 } else if (!jeb->used_size && !jeb->unchecked_size) { 693 if (jeb == c->gcblock) { 694 jffs2_dbg(1, "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", 695 jeb->offset); 696 c->gcblock = NULL; 697 } else { 698 jffs2_dbg(1, "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", 699 jeb->offset); 700 list_del(&jeb->list); 701 } 702 if (jffs2_wbuf_dirty(c)) { 703 jffs2_dbg(1, "...and adding to erasable_pending_wbuf_list\n"); 704 list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list); 705 } else { 706 if (jiffies & 127) { 707 /* Most of the time, we just erase it immediately. Otherwise we 708 spend ages scanning it on mount, etc. */ 709 jffs2_dbg(1, "...and adding to erase_pending_list\n"); 710 list_add_tail(&jeb->list, &c->erase_pending_list); 711 c->nr_erasing_blocks++; 712 jffs2_garbage_collect_trigger(c); 713 } else { 714 /* Sometimes, however, we leave it elsewhere so it doesn't get 715 immediately reused, and we spread the load a bit. */ 716 jffs2_dbg(1, "...and adding to erasable_list\n"); 717 list_add_tail(&jeb->list, &c->erasable_list); 718 } 719 } 720 jffs2_dbg(1, "Done OK\n"); 721 } else if (jeb == c->gcblock) { 722 jffs2_dbg(2, "Not moving gcblock 0x%08x to dirty_list\n", 723 jeb->offset); 724 } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) { 725 jffs2_dbg(1, "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", 726 jeb->offset); 727 list_del(&jeb->list); 728 jffs2_dbg(1, "...and adding to dirty_list\n"); 729 list_add_tail(&jeb->list, &c->dirty_list); 730 } else if (VERYDIRTY(c, jeb->dirty_size) && 731 !VERYDIRTY(c, jeb->dirty_size - addedsize)) { 732 jffs2_dbg(1, "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", 733 jeb->offset); 734 list_del(&jeb->list); 735 jffs2_dbg(1, "...and adding to very_dirty_list\n"); 736 list_add_tail(&jeb->list, &c->very_dirty_list); 737 } else { 738 jffs2_dbg(1, "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n", 739 jeb->offset, jeb->free_size, jeb->dirty_size, 740 jeb->used_size); 741 } 742 743 spin_unlock(&c->erase_completion_lock); 744 745 if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) || 746 (c->flags & JFFS2_SB_FLAG_BUILDING)) { 747 /* We didn't lock the erase_free_sem */ 748 return; 749 } 750 751 /* The erase_free_sem is locked, and has been since before we marked the node obsolete 752 and potentially put its eraseblock onto the erase_pending_list. Thus, we know that 753 the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet 754 by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */ 755 756 jffs2_dbg(1, "obliterating obsoleted node at 0x%08x\n", 757 ref_offset(ref)); 758 ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n); 759 if (ret) { 760 pr_warn("Read error reading from obsoleted node at 0x%08x: %d\n", 761 ref_offset(ref), ret); 762 goto out_erase_sem; 763 } 764 if (retlen != sizeof(n)) { 765 pr_warn("Short read from obsoleted node at 0x%08x: %zd\n", 766 ref_offset(ref), retlen); 767 goto out_erase_sem; 768 } 769 if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) { 770 pr_warn("Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", 771 je32_to_cpu(n.totlen), freed_len); 772 goto out_erase_sem; 773 } 774 if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) { 775 jffs2_dbg(1, "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", 776 ref_offset(ref), je16_to_cpu(n.nodetype)); 777 goto out_erase_sem; 778 } 779 /* XXX FIXME: This is ugly now */ 780 n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE); 781 ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n); 782 if (ret) { 783 pr_warn("Write error in obliterating obsoleted node at 0x%08x: %d\n", 784 ref_offset(ref), ret); 785 goto out_erase_sem; 786 } 787 if (retlen != sizeof(n)) { 788 pr_warn("Short write in obliterating obsoleted node at 0x%08x: %zd\n", 789 ref_offset(ref), retlen); 790 goto out_erase_sem; 791 } 792 793 /* Nodes which have been marked obsolete no longer need to be 794 associated with any inode. Remove them from the per-inode list. 795 796 Note we can't do this for NAND at the moment because we need 797 obsolete dirent nodes to stay on the lists, because of the 798 horridness in jffs2_garbage_collect_deletion_dirent(). Also 799 because we delete the inocache, and on NAND we need that to 800 stay around until all the nodes are actually erased, in order 801 to stop us from giving the same inode number to another newly 802 created inode. */ 803 if (ref->next_in_ino) { 804 struct jffs2_inode_cache *ic; 805 struct jffs2_raw_node_ref **p; 806 807 spin_lock(&c->erase_completion_lock); 808 809 ic = jffs2_raw_ref_to_ic(ref); 810 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino)) 811 ; 812 813 *p = ref->next_in_ino; 814 ref->next_in_ino = NULL; 815 816 switch (ic->class) { 817#ifdef CONFIG_JFFS2_FS_XATTR 818 case RAWNODE_CLASS_XATTR_DATUM: 819 jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic); 820 break; 821 case RAWNODE_CLASS_XATTR_REF: 822 jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic); 823 break; 824#endif 825 default: 826 if (ic->nodes == (void *)ic && ic->pino_nlink == 0) 827 jffs2_del_ino_cache(c, ic); 828 break; 829 } 830 spin_unlock(&c->erase_completion_lock); 831 } 832 833 out_erase_sem: 834 mutex_unlock(&c->erase_free_sem); 835} 836 837int jffs2_thread_should_wake(struct jffs2_sb_info *c) 838{ 839 int ret = 0; 840 uint32_t dirty; 841 int nr_very_dirty = 0; 842 struct jffs2_eraseblock *jeb; 843 844 if (!list_empty(&c->erase_complete_list) || 845 !list_empty(&c->erase_pending_list)) 846 return 1; 847 848 if (c->unchecked_size) { 849 jffs2_dbg(1, "jffs2_thread_should_wake(): unchecked_size %d, check_ino #%d\n", 850 c->unchecked_size, c->check_ino); 851 return 1; 852 } 853 854 /* dirty_size contains blocks on erase_pending_list 855 * those blocks are counted in c->nr_erasing_blocks. 856 * If one block is actually erased, it is not longer counted as dirty_space 857 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it 858 * with c->nr_erasing_blocks * c->sector_size again. 859 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks 860 * This helps us to force gc and pick eventually a clean block to spread the load. 861 */ 862 dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size; 863 864 if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger && 865 (dirty > c->nospc_dirty_size)) 866 ret = 1; 867 868 list_for_each_entry(jeb, &c->very_dirty_list, list) { 869 nr_very_dirty++; 870 if (nr_very_dirty == c->vdirty_blocks_gctrigger) { 871 ret = 1; 872 /* In debug mode, actually go through and count them all */ 873 D1(continue); 874 break; 875 } 876 } 877 878 jffs2_dbg(1, "%s(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n", 879 __func__, c->nr_free_blocks, c->nr_erasing_blocks, 880 c->dirty_size, nr_very_dirty, ret ? "yes" : "no"); 881 882 return ret; 883} 884