1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright (C) 2001-2003 Red Hat, Inc. 5 * 6 * Created by David Woodhouse <[email protected]> 7 * 8 * For licensing information, see the file 'LICENCE' in this directory. 9 * 10 * $Id: nodelist.c,v 1.102 2005/07/28 12:45:10 dedekind Exp $ 11 * 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/sched.h> 16 #include <linux/fs.h> 17 #include <linux/mtd/mtd.h> 18 #include <linux/rbtree.h> 19 #include <linux/crc32.h> 20 #include <linux/slab.h> 21 #include <linux/pagemap.h> 22 #include "nodelist.h" 23 24 void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list) 25 { 26 struct jffs2_full_dirent **prev = list; 27 28 JFFS2_DBG_DENTLIST("add dirent \"%s\", ino #%u\n", new->name, new->ino); 29 30 while ((*prev) && (*prev)->nhash <= new->nhash) { 31 if ((*prev)->nhash == new->nhash && !strcmp((const char *)((*prev)->name), (const char *)new->name)) { 32 /* Duplicate. Free one */ 33 if (new->version < (*prev)->version) { 34 JFFS2_DBG_DENTLIST("Eep! Marking new dirent node is obsolete, old is \"%s\", ino #%u\n", 35 (*prev)->name, (*prev)->ino); 36 jffs2_mark_node_obsolete(c, new->raw); 37 jffs2_free_full_dirent(new); 38 } else { 39 JFFS2_DBG_DENTLIST("marking old dirent \"%s\", ino #%u bsolete\n", 40 (*prev)->name, (*prev)->ino); 41 new->next = (*prev)->next; 42 jffs2_mark_node_obsolete(c, ((*prev)->raw)); 43 jffs2_free_full_dirent(*prev); 44 *prev = new; 45 } 46 return; 47 } 48 prev = &((*prev)->next); 49 } 50 new->next = *prev; 51 *prev = new; 52 } 53 54 void jffs2_obsolete_node_frag(struct jffs2_sb_info *c, struct jffs2_node_frag *this) 55 { 56 if (this->node) { 57 this->node->frags--; 58 if (!this->node->frags) { 59 /* The node has no valid frags left. It's totally obsoleted */ 60 JFFS2_DBG_FRAGTREE2("marking old node @0x%08x (0x%04x-0x%04x) obsolete\n", 61 ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size); 62 jffs2_mark_node_obsolete(c, this->node->raw); 63 jffs2_free_full_dnode(this->node); 64 } else { 65 JFFS2_DBG_FRAGTREE2("marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n", 66 ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size, this->node->frags); 67 mark_ref_normal(this->node->raw); 68 } 69 70 } 71 jffs2_free_node_frag(this); 72 } 73 74 static void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base) 75 { 76 struct rb_node *parent = &base->rb; 77 struct rb_node **link = &parent; 78 79 JFFS2_DBG_FRAGTREE2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size); 80 81 while (*link) { 82 parent = *link; 83 base = rb_entry(parent, struct jffs2_node_frag, rb); 84 85 JFFS2_DBG_FRAGTREE2("considering frag at 0x%08x\n", base->ofs); 86 if (newfrag->ofs > base->ofs) 87 link = &base->rb.rb_right; 88 else if (newfrag->ofs < base->ofs) 89 link = &base->rb.rb_left; 90 else { 91 JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base); 92 BUG(); 93 } 94 } 95 96 rb_link_node(&newfrag->rb, &base->rb, link); 97 } 98 99 /* Doesn't set inode->i_size */ 100 static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *list, struct jffs2_node_frag *newfrag) 101 { 102 struct jffs2_node_frag *this; 103 uint32_t lastend; 104 105 /* Skip all the nodes which are completed before this one starts */ 106 this = jffs2_lookup_node_frag(list, newfrag->node->ofs); 107 108 if (this) { 109 JFFS2_DBG_FRAGTREE2("lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n", 110 this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this); 111 lastend = this->ofs + this->size; 112 } else { 113 JFFS2_DBG_FRAGTREE2("lookup gave no frag\n"); 114 lastend = 0; 115 } 116 117 /* See if we ran off the end of the list */ 118 if (lastend <= newfrag->ofs) { 119 /* We did */ 120 121 /* Check if 'this' node was on the same page as the new node. 122 If so, both 'this' and the new node get marked REF_NORMAL so 123 the GC can take a look. 124 */ 125 if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) { 126 if (this->node) 127 mark_ref_normal(this->node->raw); 128 mark_ref_normal(newfrag->node->raw); 129 } 130 131 if (lastend < newfrag->node->ofs) { 132 /* ... and we need to put a hole in before the new node */ 133 struct jffs2_node_frag *holefrag = jffs2_alloc_node_frag(); 134 if (!holefrag) { 135 jffs2_free_node_frag(newfrag); 136 return -ENOMEM; 137 } 138 holefrag->ofs = lastend; 139 holefrag->size = newfrag->node->ofs - lastend; 140 holefrag->node = NULL; 141 if (this) { 142 /* By definition, the 'this' node has no right-hand child, 143 because there are no frags with offset greater than it. 144 So that's where we want to put the hole */ 145 JFFS2_DBG_FRAGTREE2("adding hole frag (%p) on right of node at (%p)\n", holefrag, this); 146 rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right); 147 } else { 148 JFFS2_DBG_FRAGTREE2("adding hole frag (%p) at root of tree\n", holefrag); 149 rb_link_node(&holefrag->rb, NULL, &list->rb_node); 150 } 151 rb_insert_color(&holefrag->rb, list); 152 this = holefrag; 153 } 154 if (this) { 155 /* By definition, the 'this' node has no right-hand child, 156 because there are no frags with offset greater than it. 157 So that's where we want to put new fragment */ 158 JFFS2_DBG_FRAGTREE2("adding new frag (%p) on right of node at (%p)\n", newfrag, this); 159 rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right); 160 } else { 161 JFFS2_DBG_FRAGTREE2("adding new frag (%p) at root of tree\n", newfrag); 162 rb_link_node(&newfrag->rb, NULL, &list->rb_node); 163 } 164 rb_insert_color(&newfrag->rb, list); 165 return 0; 166 } 167 168 JFFS2_DBG_FRAGTREE2("dealing with frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n", 169 this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this); 170 171 /* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes, 172 * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs 173 */ 174 if (newfrag->ofs > this->ofs) { 175 /* This node isn't completely obsoleted. The start of it remains valid */ 176 177 /* Mark the new node and the partially covered node REF_NORMAL -- let 178 the GC take a look at them */ 179 mark_ref_normal(newfrag->node->raw); 180 if (this->node) 181 mark_ref_normal(this->node->raw); 182 183 if (this->ofs + this->size > newfrag->ofs + newfrag->size) { 184 /* The new node splits 'this' frag into two */ 185 struct jffs2_node_frag *newfrag2 = jffs2_alloc_node_frag(); 186 if (!newfrag2) { 187 jffs2_free_node_frag(newfrag); 188 return -ENOMEM; 189 } 190 if (this->node) 191 JFFS2_DBG_FRAGTREE2("split old frag 0x%04x-0x%04x, phys 0x%08x\n", 192 this->ofs, this->ofs+this->size, ref_offset(this->node->raw)); 193 else 194 JFFS2_DBG_FRAGTREE2("split old hole frag 0x%04x-0x%04x\n", 195 this->ofs, this->ofs+this->size, ref_offset(this->node->raw)); 196 197 /* New second frag pointing to this's node */ 198 newfrag2->ofs = newfrag->ofs + newfrag->size; 199 newfrag2->size = (this->ofs+this->size) - newfrag2->ofs; 200 newfrag2->node = this->node; 201 if (this->node) 202 this->node->frags++; 203 204 /* Adjust size of original 'this' */ 205 this->size = newfrag->ofs - this->ofs; 206 207 /* Now, we know there's no node with offset 208 greater than this->ofs but smaller than 209 newfrag2->ofs or newfrag->ofs, for obvious 210 reasons. So we can do a tree insert from 211 'this' to insert newfrag, and a tree insert 212 from newfrag to insert newfrag2. */ 213 jffs2_fragtree_insert(newfrag, this); 214 rb_insert_color(&newfrag->rb, list); 215 216 jffs2_fragtree_insert(newfrag2, newfrag); 217 rb_insert_color(&newfrag2->rb, list); 218 219 return 0; 220 } 221 /* New node just reduces 'this' frag in size, doesn't split it */ 222 this->size = newfrag->ofs - this->ofs; 223 224 /* Again, we know it lives down here in the tree */ 225 jffs2_fragtree_insert(newfrag, this); 226 rb_insert_color(&newfrag->rb, list); 227 } else { 228 /* New frag starts at the same point as 'this' used to. Replace 229 it in the tree without doing a delete and insertion */ 230 JFFS2_DBG_FRAGTREE2("inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n", 231 newfrag, newfrag->ofs, newfrag->ofs+newfrag->size, this, this->ofs, this->ofs+this->size); 232 233 rb_replace_node(&this->rb, &newfrag->rb, list); 234 235 if (newfrag->ofs + newfrag->size >= this->ofs+this->size) { 236 JFFS2_DBG_FRAGTREE2("obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size); 237 jffs2_obsolete_node_frag(c, this); 238 } else { 239 this->ofs += newfrag->size; 240 this->size -= newfrag->size; 241 242 jffs2_fragtree_insert(this, newfrag); 243 rb_insert_color(&this->rb, list); 244 return 0; 245 } 246 } 247 /* OK, now we have newfrag added in the correct place in the tree, but 248 frag_next(newfrag) may be a fragment which is overlapped by it 249 */ 250 while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) { 251 /* 'this' frag is obsoleted completely. */ 252 JFFS2_DBG_FRAGTREE2("obsoleting node frag %p (%x-%x) and removing from tree\n", 253 this, this->ofs, this->ofs+this->size); 254 rb_erase(&this->rb, list); 255 jffs2_obsolete_node_frag(c, this); 256 } 257 /* Now we're pointing at the first frag which isn't totally obsoleted by 258 the new frag */ 259 260 if (!this || newfrag->ofs + newfrag->size == this->ofs) { 261 return 0; 262 } 263 /* Still some overlap but we don't need to move it in the tree */ 264 this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size); 265 this->ofs = newfrag->ofs + newfrag->size; 266 267 /* And mark them REF_NORMAL so the GC takes a look at them */ 268 if (this->node) 269 mark_ref_normal(this->node->raw); 270 mark_ref_normal(newfrag->node->raw); 271 272 return 0; 273 } 274 275 /* Given an inode, probably with existing list of fragments, add the new node 276 * to the fragment list. 277 */ 278 int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn) 279 { 280 int ret; 281 struct jffs2_node_frag *newfrag; 282 283 if (unlikely(!fn->size)) 284 return 0; 285 286 newfrag = jffs2_alloc_node_frag(); 287 if (unlikely(!newfrag)) 288 return -ENOMEM; 289 290 JFFS2_DBG_FRAGTREE("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n", 291 fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag); 292 293 newfrag->ofs = fn->ofs; 294 newfrag->size = fn->size; 295 newfrag->node = fn; 296 newfrag->node->frags = 1; 297 298 ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag); 299 if (unlikely(ret)) 300 return ret; 301 302 /* If we now share a page with other nodes, mark either previous 303 or next node REF_NORMAL, as appropriate. */ 304 if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) { 305 struct jffs2_node_frag *prev = frag_prev(newfrag); 306 307 mark_ref_normal(fn->raw); 308 /* If we don't start at zero there's _always_ a previous */ 309 if (prev->node) 310 mark_ref_normal(prev->node->raw); 311 } 312 313 if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) { 314 struct jffs2_node_frag *next = frag_next(newfrag); 315 316 if (next) { 317 mark_ref_normal(fn->raw); 318 if (next->node) 319 mark_ref_normal(next->node->raw); 320 } 321 } 322 jffs2_dbg_fragtree_paranoia_check_nolock(f); 323 jffs2_dbg_dump_fragtree_nolock(f); 324 return 0; 325 } 326 327 328 void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state) 329 { 330 spin_lock(&c->inocache_lock); 331 ic->state = state; 332 wake_up(&c->inocache_wq); 333 spin_unlock(&c->inocache_lock); 334 } 335 336 /* During mount, this needs no locking. During normal operation, its 337 callers want to do other stuff while still holding the inocache_lock. 338 Rather than introducing special case get_ino_cache functions or 339 callbacks, we just let the caller do the locking itself. */ 340 341 struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino) 342 { 343 struct jffs2_inode_cache *ret; 344 345 ret = c->inocache_list[ino % INOCACHE_HASHSIZE]; 346 while (ret && ret->ino < ino) { 347 ret = ret->next; 348 } 349 350 if (ret && ret->ino != ino) 351 ret = NULL; 352 353 return ret; 354 } 355 356 void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new) 357 { 358 struct jffs2_inode_cache **prev; 359 360 spin_lock(&c->inocache_lock); 361 if (!new->ino) 362 new->ino = ++c->highest_ino; 363 364 JFFS2_DBG_INOCACHE("add %p (ino #%u)\n", new, new->ino); 365 366 prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE]; 367 368 while ((*prev) && (*prev)->ino < new->ino) { 369 prev = &(*prev)->next; 370 } 371 new->next = *prev; 372 *prev = new; 373 374 spin_unlock(&c->inocache_lock); 375 } 376 377 void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old) 378 { 379 struct jffs2_inode_cache **prev; 380 381 JFFS2_DBG_INOCACHE("del %p (ino #%u)\n", old, old->ino); 382 spin_lock(&c->inocache_lock); 383 384 prev = &c->inocache_list[old->ino % INOCACHE_HASHSIZE]; 385 386 while ((*prev) && (*prev)->ino < old->ino) { 387 prev = &(*prev)->next; 388 } 389 if ((*prev) == old) { 390 *prev = old->next; 391 } 392 393 /* Free it now unless it's in READING or CLEARING state, which 394 are the transitions upon read_inode() and clear_inode(). The 395 rest of the time we know nobody else is looking at it, and 396 if it's held by read_inode() or clear_inode() they'll free it 397 for themselves. */ 398 if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING) 399 jffs2_free_inode_cache(old); 400 401 spin_unlock(&c->inocache_lock); 402 } 403 404 void jffs2_free_ino_caches(struct jffs2_sb_info *c) 405 { 406 int i; 407 struct jffs2_inode_cache *this, *next; 408 409 for (i=0; i<INOCACHE_HASHSIZE; i++) { 410 this = c->inocache_list[i]; 411 while (this) { 412 next = this->next; 413 jffs2_free_inode_cache(this); 414 this = next; 415 } 416 c->inocache_list[i] = NULL; 417 } 418 } 419 420 void jffs2_free_raw_node_refs(struct jffs2_sb_info *c) 421 { 422 int i; 423 struct jffs2_raw_node_ref *this, *next; 424 425 for (i=0; i<c->nr_blocks; i++) { 426 this = c->blocks[i].first_node; 427 while(this) { 428 next = this->next_phys; 429 jffs2_free_raw_node_ref(this); 430 this = next; 431 } 432 c->blocks[i].first_node = c->blocks[i].last_node = NULL; 433 } 434 } 435 436 struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset) 437 { 438 /* The common case in lookup is that there will be a node 439 which precisely matches. So we go looking for that first */ 440 struct rb_node *next; 441 struct jffs2_node_frag *prev = NULL; 442 struct jffs2_node_frag *frag = NULL; 443 444 JFFS2_DBG_FRAGTREE2("root %p, offset %d\n", fragtree, offset); 445 446 next = fragtree->rb_node; 447 448 while(next) { 449 frag = rb_entry(next, struct jffs2_node_frag, rb); 450 451 JFFS2_DBG_FRAGTREE2("considering frag %#04x-%#04x (%p). left %p, right %p\n", 452 frag->ofs, frag->ofs+frag->size, frag, frag->rb.rb_left, frag->rb.rb_right); 453 if (frag->ofs + frag->size <= offset) { 454 JFFS2_DBG_FRAGTREE2("going right from frag %#04x-%#04x, before the region we care about\n", 455 frag->ofs, frag->ofs+frag->size); 456 /* Remember the closest smaller match on the way down */ 457 if (!prev || frag->ofs > prev->ofs) 458 prev = frag; 459 next = frag->rb.rb_right; 460 } else if (frag->ofs > offset) { 461 JFFS2_DBG_FRAGTREE2("going left from frag %#04x-%#04x, after the region we care about\n", 462 frag->ofs, frag->ofs+frag->size); 463 next = frag->rb.rb_left; 464 } else { 465 JFFS2_DBG_FRAGTREE2("returning frag %#04x-%#04x, matched\n", 466 frag->ofs, frag->ofs+frag->size); 467 return frag; 468 } 469 } 470 471 /* Exact match not found. Go back up looking at each parent, 472 and return the closest smaller one */ 473 474 if (prev) 475 JFFS2_DBG_FRAGTREE2("no match. Returning frag %#04x-%#04x, closest previous\n", 476 prev->ofs, prev->ofs+prev->size); 477 else 478 JFFS2_DBG_FRAGTREE2("returning NULL, empty fragtree\n"); 479 480 return prev; 481 } 482 483 /* Pass 'c' argument to indicate that nodes should be marked obsolete as 484 they're killed. */ 485 void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c) 486 { 487 struct jffs2_node_frag *frag; 488 struct jffs2_node_frag *parent; 489 490 if (!root->rb_node) 491 return; 492 493 JFFS2_DBG_FRAGTREE("killing\n"); 494 495 frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb)); 496 while(frag) { 497 if (frag->rb.rb_left) { 498 JFFS2_DBG_FRAGTREE2("going left from frag (%p) %#04x-%#04x\n", 499 frag, frag->ofs, frag->ofs+frag->size); 500 frag = frag_left(frag); 501 continue; 502 } 503 if (frag->rb.rb_right) { 504 JFFS2_DBG_FRAGTREE2("going right from frag (%p) %#04x-%#04x\n", 505 frag, frag->ofs, frag->ofs+frag->size); 506 frag = frag_right(frag); 507 continue; 508 } 509 510 JFFS2_DBG_FRAGTREE2("frag %#04x-%#04x: node %p, frags %d\n", 511 frag->ofs, frag->ofs+frag->size, frag->node, frag->node?frag->node->frags:0); 512 513 if (frag->node && !(--frag->node->frags)) { 514 /* Not a hole, and it's the final remaining frag 515 of this node. Free the node */ 516 if (c) 517 jffs2_mark_node_obsolete(c, frag->node->raw); 518 519 jffs2_free_full_dnode(frag->node); 520 } 521 parent = frag_parent(frag); 522 if (parent) { 523 if (frag_left(parent) == frag) 524 parent->rb.rb_left = NULL; 525 else 526 parent->rb.rb_right = NULL; 527 } 528 529 jffs2_free_node_frag(frag); 530 frag = parent; 531 532 cond_resched(); 533 } 534 } 535