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/sched.h>
  16#include <linux/slab.h>
  17#include <linux/fs.h>
  18#include <linux/crc32.h>
  19#include <linux/pagemap.h>
  20#include <linux/mtd/mtd.h>
  21#include <linux/compiler.h>
  22#include "nodelist.h"
  23
  24/*
  25 * Check the data CRC of the node.
  26 *
  27 * Returns: 0 if the data CRC is correct;
  28 * 	    1 - if incorrect;
  29 *	    error code if an error occurred.
  30 */
  31static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
  32{
  33	struct jffs2_raw_node_ref *ref = tn->fn->raw;
  34	int err = 0, pointed = 0;
  35	struct jffs2_eraseblock *jeb;
  36	unsigned char *buffer;
  37	uint32_t crc, ofs, len;
  38	size_t retlen;
  39
  40	BUG_ON(tn->csize == 0);
  41
  42	/* Calculate how many bytes were already checked */
  43	ofs = ref_offset(ref) + sizeof(struct jffs2_raw_inode);
  44	len = tn->csize;
  45
  46	if (jffs2_is_writebuffered(c)) {
  47		int adj = ofs % c->wbuf_pagesize;
  48		if (likely(adj))
  49			adj = c->wbuf_pagesize - adj;
  50
  51		if (adj >= tn->csize) {
  52			dbg_readinode("no need to check node at %#08x, data length %u, data starts at %#08x - it has already been checked.\n",
  53				      ref_offset(ref), tn->csize, ofs);
  54			goto adj_acc;
  55		}
  56
  57		ofs += adj;
  58		len -= adj;
  59	}
  60
  61	dbg_readinode("check node at %#08x, data length %u, partial CRC %#08x, correct CRC %#08x, data starts at %#08x, start checking from %#08x - %u bytes.\n",
  62		ref_offset(ref), tn->csize, tn->partial_crc, tn->data_crc, ofs - len, ofs, len);
  63
  64#ifndef __ECOS
  65	/* TODO: instead, incapsulate point() stuff to jffs2_flash_read(),
  66	 * adding and jffs2_flash_read_end() interface. */
  67	err = mtd_point(c->mtd, ofs, len, &retlen, (void **)&buffer, NULL);
  68	if (!err && retlen < len) {
  69		JFFS2_WARNING("MTD point returned len too short: %zu instead of %u.\n", retlen, tn->csize);
  70		mtd_unpoint(c->mtd, ofs, retlen);
  71	} else if (err) {
  72		if (err != -EOPNOTSUPP)
 
  73			JFFS2_WARNING("MTD point failed: error code %d.\n", err);
  74	} else
  75		pointed = 1; /* successfully pointed to device */
 
  76#endif
  77
  78	if (!pointed) {
  79		buffer = kmalloc(len, GFP_KERNEL);
  80		if (unlikely(!buffer))
  81			return -ENOMEM;
  82
  83		/* TODO: this is very frequent pattern, make it a separate
  84		 * routine */
  85		err = jffs2_flash_read(c, ofs, len, &retlen, buffer);
  86		if (err) {
  87			JFFS2_ERROR("can not read %d bytes from 0x%08x, error code: %d.\n", len, ofs, err);
  88			goto free_out;
  89		}
  90
  91		if (retlen != len) {
  92			JFFS2_ERROR("short read at %#08x: %zd instead of %d.\n", ofs, retlen, len);
  93			err = -EIO;
  94			goto free_out;
  95		}
  96	}
  97
  98	/* Continue calculating CRC */
  99	crc = crc32(tn->partial_crc, buffer, len);
 100	if(!pointed)
 101		kfree(buffer);
 102#ifndef __ECOS
 103	else
 104		mtd_unpoint(c->mtd, ofs, len);
 105#endif
 106
 107	if (crc != tn->data_crc) {
 108		JFFS2_NOTICE("wrong data CRC in data node at 0x%08x: read %#08x, calculated %#08x.\n",
 109			     ref_offset(ref), tn->data_crc, crc);
 110		return 1;
 111	}
 112
 113adj_acc:
 114	jeb = &c->blocks[ref->flash_offset / c->sector_size];
 115	len = ref_totlen(c, jeb, ref);
 116	/* If it should be REF_NORMAL, it'll get marked as such when
 117	   we build the fragtree, shortly. No need to worry about GC
 118	   moving it while it's marked REF_PRISTINE -- GC won't happen
 119	   till we've finished checking every inode anyway. */
 120	ref->flash_offset |= REF_PRISTINE;
 121	/*
 122	 * Mark the node as having been checked and fix the
 123	 * accounting accordingly.
 124	 */
 125	spin_lock(&c->erase_completion_lock);
 126	jeb->used_size += len;
 127	jeb->unchecked_size -= len;
 128	c->used_size += len;
 129	c->unchecked_size -= len;
 130	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 131	spin_unlock(&c->erase_completion_lock);
 132
 133	return 0;
 134
 135free_out:
 136	if(!pointed)
 137		kfree(buffer);
 138#ifndef __ECOS
 139	else
 140		mtd_unpoint(c->mtd, ofs, len);
 141#endif
 142	return err;
 143}
 144
 145/*
 146 * Helper function for jffs2_add_older_frag_to_fragtree().
 147 *
 148 * Checks the node if we are in the checking stage.
 149 */
 150static int check_tn_node(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
 151{
 152	int ret;
 153
 154	BUG_ON(ref_obsolete(tn->fn->raw));
 155
 156	/* We only check the data CRC of unchecked nodes */
 157	if (ref_flags(tn->fn->raw) != REF_UNCHECKED)
 158		return 0;
 159
 160	dbg_readinode("check node %#04x-%#04x, phys offs %#08x\n",
 161		      tn->fn->ofs, tn->fn->ofs + tn->fn->size, ref_offset(tn->fn->raw));
 162
 163	ret = check_node_data(c, tn);
 164	if (unlikely(ret < 0)) {
 165		JFFS2_ERROR("check_node_data() returned error: %d.\n",
 166			ret);
 167	} else if (unlikely(ret > 0)) {
 168		dbg_readinode("CRC error, mark it obsolete.\n");
 169		jffs2_mark_node_obsolete(c, tn->fn->raw);
 170	}
 171
 172	return ret;
 173}
 174
 175static struct jffs2_tmp_dnode_info *jffs2_lookup_tn(struct rb_root *tn_root, uint32_t offset)
 176{
 177	struct rb_node *next;
 178	struct jffs2_tmp_dnode_info *tn = NULL;
 179
 180	dbg_readinode("root %p, offset %d\n", tn_root, offset);
 181
 182	next = tn_root->rb_node;
 183
 184	while (next) {
 185		tn = rb_entry(next, struct jffs2_tmp_dnode_info, rb);
 186
 187		if (tn->fn->ofs < offset)
 188			next = tn->rb.rb_right;
 189		else if (tn->fn->ofs >= offset)
 190			next = tn->rb.rb_left;
 191		else
 192			break;
 193	}
 194
 195	return tn;
 196}
 197
 198
 199static void jffs2_kill_tn(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
 200{
 201	jffs2_mark_node_obsolete(c, tn->fn->raw);
 202	jffs2_free_full_dnode(tn->fn);
 203	jffs2_free_tmp_dnode_info(tn);
 204}
 205/*
 206 * This function is used when we read an inode. Data nodes arrive in
 207 * arbitrary order -- they may be older or newer than the nodes which
 208 * are already in the tree. Where overlaps occur, the older node can
 209 * be discarded as long as the newer passes the CRC check. We don't
 210 * bother to keep track of holes in this rbtree, and neither do we deal
 211 * with frags -- we can have multiple entries starting at the same
 212 * offset, and the one with the smallest length will come first in the
 213 * ordering.
 214 *
 215 * Returns 0 if the node was handled (including marking it obsolete)
 216 *	 < 0 an if error occurred
 217 */
 218static int jffs2_add_tn_to_tree(struct jffs2_sb_info *c,
 219				struct jffs2_readinode_info *rii,
 220				struct jffs2_tmp_dnode_info *tn)
 221{
 222	uint32_t fn_end = tn->fn->ofs + tn->fn->size;
 223	struct jffs2_tmp_dnode_info *this, *ptn;
 224
 225	dbg_readinode("insert fragment %#04x-%#04x, ver %u at %08x\n", tn->fn->ofs, fn_end, tn->version, ref_offset(tn->fn->raw));
 226
 227	/* If a node has zero dsize, we only have to keep it if it might be the
 228	   node with highest version -- i.e. the one which will end up as f->metadata.
 229	   Note that such nodes won't be REF_UNCHECKED since there are no data to
 230	   check anyway. */
 231	if (!tn->fn->size) {
 232		if (rii->mdata_tn) {
 233			if (rii->mdata_tn->version < tn->version) {
 234				/* We had a candidate mdata node already */
 235				dbg_readinode("kill old mdata with ver %d\n", rii->mdata_tn->version);
 236				jffs2_kill_tn(c, rii->mdata_tn);
 237			} else {
 238				dbg_readinode("kill new mdata with ver %d (older than existing %d\n",
 239					      tn->version, rii->mdata_tn->version);
 240				jffs2_kill_tn(c, tn);
 241				return 0;
 242			}
 243		}
 244		rii->mdata_tn = tn;
 245		dbg_readinode("keep new mdata with ver %d\n", tn->version);
 246		return 0;
 247	}
 248
 249	/* Find the earliest node which _may_ be relevant to this one */
 250	this = jffs2_lookup_tn(&rii->tn_root, tn->fn->ofs);
 251	if (this) {
 252		/* If the node is coincident with another at a lower address,
 253		   back up until the other node is found. It may be relevant */
 254		while (this->overlapped) {
 255			ptn = tn_prev(this);
 256			if (!ptn) {
 257				/*
 258				 * We killed a node which set the overlapped
 259				 * flags during the scan. Fix it up.
 260				 */
 261				this->overlapped = 0;
 262				break;
 263			}
 264			this = ptn;
 265		}
 266		dbg_readinode("'this' found %#04x-%#04x (%s)\n", this->fn->ofs, this->fn->ofs + this->fn->size, this->fn ? "data" : "hole");
 267	}
 268
 269	while (this) {
 270		if (this->fn->ofs > fn_end)
 271			break;
 272		dbg_readinode("Ponder this ver %d, 0x%x-0x%x\n",
 273			      this->version, this->fn->ofs, this->fn->size);
 274
 275		if (this->version == tn->version) {
 276			/* Version number collision means REF_PRISTINE GC. Accept either of them
 277			   as long as the CRC is correct. Check the one we have already...  */
 278			if (!check_tn_node(c, this)) {
 279				/* The one we already had was OK. Keep it and throw away the new one */
 280				dbg_readinode("Like old node. Throw away new\n");
 281				jffs2_kill_tn(c, tn);
 282				return 0;
 283			} else {
 284				/* Who cares if the new one is good; keep it for now anyway. */
 285				dbg_readinode("Like new node. Throw away old\n");
 286				rb_replace_node(&this->rb, &tn->rb, &rii->tn_root);
 287				jffs2_kill_tn(c, this);
 288				/* Same overlapping from in front and behind */
 289				return 0;
 290			}
 291		}
 292		if (this->version < tn->version &&
 293		    this->fn->ofs >= tn->fn->ofs &&
 294		    this->fn->ofs + this->fn->size <= fn_end) {
 295			/* New node entirely overlaps 'this' */
 296			if (check_tn_node(c, tn)) {
 297				dbg_readinode("new node bad CRC\n");
 298				jffs2_kill_tn(c, tn);
 299				return 0;
 300			}
 301			/* ... and is good. Kill 'this' and any subsequent nodes which are also overlapped */
 302			while (this && this->fn->ofs + this->fn->size <= fn_end) {
 303				struct jffs2_tmp_dnode_info *next = tn_next(this);
 304				if (this->version < tn->version) {
 305					tn_erase(this, &rii->tn_root);
 306					dbg_readinode("Kill overlapped ver %d, 0x%x-0x%x\n",
 307						      this->version, this->fn->ofs,
 308						      this->fn->ofs+this->fn->size);
 309					jffs2_kill_tn(c, this);
 310				}
 311				this = next;
 312			}
 313			dbg_readinode("Done killing overlapped nodes\n");
 314			continue;
 315		}
 316		if (this->version > tn->version &&
 317		    this->fn->ofs <= tn->fn->ofs &&
 318		    this->fn->ofs+this->fn->size >= fn_end) {
 319			/* New node entirely overlapped by 'this' */
 320			if (!check_tn_node(c, this)) {
 321				dbg_readinode("Good CRC on old node. Kill new\n");
 322				jffs2_kill_tn(c, tn);
 323				return 0;
 324			}
 325			/* ... but 'this' was bad. Replace it... */
 326			dbg_readinode("Bad CRC on old overlapping node. Kill it\n");
 327			tn_erase(this, &rii->tn_root);
 328			jffs2_kill_tn(c, this);
 329			break;
 330		}
 331
 332		this = tn_next(this);
 333	}
 334
 335	/* We neither completely obsoleted nor were completely
 336	   obsoleted by an earlier node. Insert into the tree */
 337	{
 338		struct rb_node *parent;
 339		struct rb_node **link = &rii->tn_root.rb_node;
 340		struct jffs2_tmp_dnode_info *insert_point = NULL;
 341
 342		while (*link) {
 343			parent = *link;
 344			insert_point = rb_entry(parent, struct jffs2_tmp_dnode_info, rb);
 345			if (tn->fn->ofs > insert_point->fn->ofs)
 346				link = &insert_point->rb.rb_right;
 347			else if (tn->fn->ofs < insert_point->fn->ofs ||
 348				 tn->fn->size < insert_point->fn->size)
 349				link = &insert_point->rb.rb_left;
 350			else
 351				link = &insert_point->rb.rb_right;
 352		}
 353		rb_link_node(&tn->rb, &insert_point->rb, link);
 354		rb_insert_color(&tn->rb, &rii->tn_root);
 355	}
 356
 357	/* If there's anything behind that overlaps us, note it */
 358	this = tn_prev(tn);
 359	if (this) {
 360		while (1) {
 361			if (this->fn->ofs + this->fn->size > tn->fn->ofs) {
 362				dbg_readinode("Node is overlapped by %p (v %d, 0x%x-0x%x)\n",
 363					      this, this->version, this->fn->ofs,
 364					      this->fn->ofs+this->fn->size);
 365				tn->overlapped = 1;
 366				break;
 367			}
 368			if (!this->overlapped)
 369				break;
 370
 371			ptn = tn_prev(this);
 372			if (!ptn) {
 373				/*
 374				 * We killed a node which set the overlapped
 375				 * flags during the scan. Fix it up.
 376				 */
 377				this->overlapped = 0;
 378				break;
 379			}
 380			this = ptn;
 381		}
 382	}
 383
 384	/* If the new node overlaps anything ahead, note it */
 385	this = tn_next(tn);
 386	while (this && this->fn->ofs < fn_end) {
 387		this->overlapped = 1;
 388		dbg_readinode("Node ver %d, 0x%x-0x%x is overlapped\n",
 389			      this->version, this->fn->ofs,
 390			      this->fn->ofs+this->fn->size);
 391		this = tn_next(this);
 392	}
 393	return 0;
 394}
 395
 396/* Trivial function to remove the last node in the tree. Which by definition
 397   has no right-hand child — so can be removed just by making its left-hand
 398   child (if any) take its place under its parent. Since this is only done
 399   when we're consuming the whole tree, there's no need to use rb_erase()
 400   and let it worry about adjusting colours and balancing the tree. That
 401   would just be a waste of time. */
 402static void eat_last(struct rb_root *root, struct rb_node *node)
 403{
 404	struct rb_node *parent = rb_parent(node);
 405	struct rb_node **link;
 406
 407	/* LAST! */
 408	BUG_ON(node->rb_right);
 409
 410	if (!parent)
 411		link = &root->rb_node;
 412	else if (node == parent->rb_left)
 413		link = &parent->rb_left;
 414	else
 415		link = &parent->rb_right;
 416
 417	*link = node->rb_left;
 
 418	if (node->rb_left)
 419		node->rb_left->__rb_parent_color = node->__rb_parent_color;
 420}
 421
 422/* We put the version tree in reverse order, so we can use the same eat_last()
 423   function that we use to consume the tmpnode tree (tn_root). */
 424static void ver_insert(struct rb_root *ver_root, struct jffs2_tmp_dnode_info *tn)
 425{
 426	struct rb_node **link = &ver_root->rb_node;
 427	struct rb_node *parent = NULL;
 428	struct jffs2_tmp_dnode_info *this_tn;
 429
 430	while (*link) {
 431		parent = *link;
 432		this_tn = rb_entry(parent, struct jffs2_tmp_dnode_info, rb);
 433
 434		if (tn->version > this_tn->version)
 435			link = &parent->rb_left;
 436		else
 437			link = &parent->rb_right;
 438	}
 439	dbg_readinode("Link new node at %p (root is %p)\n", link, ver_root);
 440	rb_link_node(&tn->rb, parent, link);
 441	rb_insert_color(&tn->rb, ver_root);
 442}
 443
 444/* Build final, normal fragtree from tn tree. It doesn't matter which order
 445   we add nodes to the real fragtree, as long as they don't overlap. And
 446   having thrown away the majority of overlapped nodes as we went, there
 447   really shouldn't be many sets of nodes which do overlap. If we start at
 448   the end, we can use the overlap markers -- we can just eat nodes which
 449   aren't overlapped, and when we encounter nodes which _do_ overlap we
 450   sort them all into a temporary tree in version order before replaying them. */
 451static int jffs2_build_inode_fragtree(struct jffs2_sb_info *c,
 452				      struct jffs2_inode_info *f,
 453				      struct jffs2_readinode_info *rii)
 454{
 455	struct jffs2_tmp_dnode_info *pen, *last, *this;
 456	struct rb_root ver_root = RB_ROOT;
 457	uint32_t high_ver = 0;
 458
 459	if (rii->mdata_tn) {
 460		dbg_readinode("potential mdata is ver %d at %p\n", rii->mdata_tn->version, rii->mdata_tn);
 461		high_ver = rii->mdata_tn->version;
 462		rii->latest_ref = rii->mdata_tn->fn->raw;
 463	}
 464#ifdef JFFS2_DBG_READINODE_MESSAGES
 465	this = tn_last(&rii->tn_root);
 466	while (this) {
 467		dbg_readinode("tn %p ver %d range 0x%x-0x%x ov %d\n", this, this->version, this->fn->ofs,
 468			      this->fn->ofs+this->fn->size, this->overlapped);
 469		this = tn_prev(this);
 470	}
 471#endif
 472	pen = tn_last(&rii->tn_root);
 473	while ((last = pen)) {
 474		pen = tn_prev(last);
 475
 476		eat_last(&rii->tn_root, &last->rb);
 477		ver_insert(&ver_root, last);
 478
 479		if (unlikely(last->overlapped)) {
 480			if (pen)
 481				continue;
 482			/*
 483			 * We killed a node which set the overlapped
 484			 * flags during the scan. Fix it up.
 485			 */
 486			last->overlapped = 0;
 487		}
 488
 489		/* Now we have a bunch of nodes in reverse version
 490		   order, in the tree at ver_root. Most of the time,
 491		   there'll actually be only one node in the 'tree',
 492		   in fact. */
 493		this = tn_last(&ver_root);
 494
 495		while (this) {
 496			struct jffs2_tmp_dnode_info *vers_next;
 497			int ret;
 498			vers_next = tn_prev(this);
 499			eat_last(&ver_root, &this->rb);
 500			if (check_tn_node(c, this)) {
 501				dbg_readinode("node ver %d, 0x%x-0x%x failed CRC\n",
 502					     this->version, this->fn->ofs,
 503					     this->fn->ofs+this->fn->size);
 504				jffs2_kill_tn(c, this);
 505			} else {
 506				if (this->version > high_ver) {
 507					/* Note that this is different from the other
 508					   highest_version, because this one is only
 509					   counting _valid_ nodes which could give the
 510					   latest inode metadata */
 511					high_ver = this->version;
 512					rii->latest_ref = this->fn->raw;
 513				}
 514				dbg_readinode("Add %p (v %d, 0x%x-0x%x, ov %d) to fragtree\n",
 515					     this, this->version, this->fn->ofs,
 516					     this->fn->ofs+this->fn->size, this->overlapped);
 517
 518				ret = jffs2_add_full_dnode_to_inode(c, f, this->fn);
 519				if (ret) {
 520					/* Free the nodes in vers_root; let the caller
 521					   deal with the rest */
 522					JFFS2_ERROR("Add node to tree failed %d\n", ret);
 523					while (1) {
 524						vers_next = tn_prev(this);
 525						if (check_tn_node(c, this))
 526							jffs2_mark_node_obsolete(c, this->fn->raw);
 527						jffs2_free_full_dnode(this->fn);
 528						jffs2_free_tmp_dnode_info(this);
 529						this = vers_next;
 530						if (!this)
 531							break;
 532						eat_last(&ver_root, &vers_next->rb);
 533					}
 534					return ret;
 535				}
 536				jffs2_free_tmp_dnode_info(this);
 537			}
 538			this = vers_next;
 539		}
 540	}
 541	return 0;
 542}
 543
 544static void jffs2_free_tmp_dnode_info_list(struct rb_root *list)
 545{
 546	struct jffs2_tmp_dnode_info *tn, *next;
 
 
 
 547
 548	rbtree_postorder_for_each_entry_safe(tn, next, list, rb) {
 
 
 
 
 
 
 
 549			jffs2_free_full_dnode(tn->fn);
 550			jffs2_free_tmp_dnode_info(tn);
 551	}
 552
 
 
 
 
 
 
 
 
 
 
 
 553	*list = RB_ROOT;
 554}
 555
 556static void jffs2_free_full_dirent_list(struct jffs2_full_dirent *fd)
 557{
 558	struct jffs2_full_dirent *next;
 559
 560	while (fd) {
 561		next = fd->next;
 562		jffs2_free_full_dirent(fd);
 563		fd = next;
 564	}
 565}
 566
 567/* Returns first valid node after 'ref'. May return 'ref' */
 568static struct jffs2_raw_node_ref *jffs2_first_valid_node(struct jffs2_raw_node_ref *ref)
 569{
 570	while (ref && ref->next_in_ino) {
 571		if (!ref_obsolete(ref))
 572			return ref;
 573		dbg_noderef("node at 0x%08x is obsoleted. Ignoring.\n", ref_offset(ref));
 574		ref = ref->next_in_ino;
 575	}
 576	return NULL;
 577}
 578
 579/*
 580 * Helper function for jffs2_get_inode_nodes().
 581 * It is called every time an directory entry node is found.
 582 *
 583 * Returns: 0 on success;
 584 * 	    negative error code on failure.
 585 */
 586static inline int read_direntry(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref,
 587				struct jffs2_raw_dirent *rd, size_t read,
 588				struct jffs2_readinode_info *rii)
 589{
 590	struct jffs2_full_dirent *fd;
 591	uint32_t crc;
 592
 593	/* Obsoleted. This cannot happen, surely? dwmw2 20020308 */
 594	BUG_ON(ref_obsolete(ref));
 595
 596	crc = crc32(0, rd, sizeof(*rd) - 8);
 597	if (unlikely(crc != je32_to_cpu(rd->node_crc))) {
 598		JFFS2_NOTICE("header CRC failed on dirent node at %#08x: read %#08x, calculated %#08x\n",
 599			     ref_offset(ref), je32_to_cpu(rd->node_crc), crc);
 600		jffs2_mark_node_obsolete(c, ref);
 601		return 0;
 602	}
 603
 604	/* If we've never checked the CRCs on this node, check them now */
 605	if (ref_flags(ref) == REF_UNCHECKED) {
 606		struct jffs2_eraseblock *jeb;
 607		int len;
 608
 609		/* Sanity check */
 610		if (unlikely(PAD((rd->nsize + sizeof(*rd))) != PAD(je32_to_cpu(rd->totlen)))) {
 611			JFFS2_ERROR("illegal nsize in node at %#08x: nsize %#02x, totlen %#04x\n",
 612				    ref_offset(ref), rd->nsize, je32_to_cpu(rd->totlen));
 613			jffs2_mark_node_obsolete(c, ref);
 614			return 0;
 615		}
 616
 617		jeb = &c->blocks[ref->flash_offset / c->sector_size];
 618		len = ref_totlen(c, jeb, ref);
 619
 620		spin_lock(&c->erase_completion_lock);
 621		jeb->used_size += len;
 622		jeb->unchecked_size -= len;
 623		c->used_size += len;
 624		c->unchecked_size -= len;
 625		ref->flash_offset = ref_offset(ref) | dirent_node_state(rd);
 626		spin_unlock(&c->erase_completion_lock);
 627	}
 628
 629	fd = jffs2_alloc_full_dirent(rd->nsize + 1);
 630	if (unlikely(!fd))
 631		return -ENOMEM;
 632
 633	fd->raw = ref;
 634	fd->version = je32_to_cpu(rd->version);
 635	fd->ino = je32_to_cpu(rd->ino);
 636	fd->type = rd->type;
 637
 638	if (fd->version > rii->highest_version)
 639		rii->highest_version = fd->version;
 640
 641	/* Pick out the mctime of the latest dirent */
 642	if(fd->version > rii->mctime_ver && je32_to_cpu(rd->mctime)) {
 643		rii->mctime_ver = fd->version;
 644		rii->latest_mctime = je32_to_cpu(rd->mctime);
 645	}
 646
 647	/*
 648	 * Copy as much of the name as possible from the raw
 649	 * dirent we've already read from the flash.
 650	 */
 651	if (read > sizeof(*rd))
 652		memcpy(&fd->name[0], &rd->name[0],
 653		       min_t(uint32_t, rd->nsize, (read - sizeof(*rd)) ));
 654
 655	/* Do we need to copy any more of the name directly from the flash? */
 656	if (rd->nsize + sizeof(*rd) > read) {
 657		/* FIXME: point() */
 658		int err;
 659		int already = read - sizeof(*rd);
 660
 661		err = jffs2_flash_read(c, (ref_offset(ref)) + read,
 662				rd->nsize - already, &read, &fd->name[already]);
 663		if (unlikely(read != rd->nsize - already) && likely(!err)) {
 664			jffs2_free_full_dirent(fd);
 665			JFFS2_ERROR("short read: wanted %d bytes, got %zd\n",
 666				    rd->nsize - already, read);
 667			return -EIO;
 668		}
 669
 670		if (unlikely(err)) {
 671			JFFS2_ERROR("read remainder of name: error %d\n", err);
 672			jffs2_free_full_dirent(fd);
 673			return -EIO;
 674		}
 675
 676#ifdef CONFIG_JFFS2_SUMMARY
 677		/*
 678		 * we use CONFIG_JFFS2_SUMMARY because without it, we
 679		 * have checked it while mounting
 680		 */
 681		crc = crc32(0, fd->name, rd->nsize);
 682		if (unlikely(crc != je32_to_cpu(rd->name_crc))) {
 683			JFFS2_NOTICE("name CRC failed on dirent node at"
 684			   "%#08x: read %#08x,calculated %#08x\n",
 685			   ref_offset(ref), je32_to_cpu(rd->node_crc), crc);
 686			jffs2_mark_node_obsolete(c, ref);
 687			jffs2_free_full_dirent(fd);
 688			return 0;
 689		}
 690#endif
 691	}
 692
 693	fd->nhash = full_name_hash(NULL, fd->name, rd->nsize);
 694	fd->next = NULL;
 695	fd->name[rd->nsize] = '\0';
 696
 697	/*
 698	 * Wheee. We now have a complete jffs2_full_dirent structure, with
 699	 * the name in it and everything. Link it into the list
 700	 */
 701	jffs2_add_fd_to_list(c, fd, &rii->fds);
 702
 703	return 0;
 704}
 705
 706/*
 707 * Helper function for jffs2_get_inode_nodes().
 708 * It is called every time an inode node is found.
 709 *
 710 * Returns: 0 on success (possibly after marking a bad node obsolete);
 711 * 	    negative error code on failure.
 712 */
 713static inline int read_dnode(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref,
 714			     struct jffs2_raw_inode *rd, int rdlen,
 715			     struct jffs2_readinode_info *rii)
 716{
 717	struct jffs2_tmp_dnode_info *tn;
 718	uint32_t len, csize;
 719	int ret = 0;
 720	uint32_t crc;
 721
 722	/* Obsoleted. This cannot happen, surely? dwmw2 20020308 */
 723	BUG_ON(ref_obsolete(ref));
 724
 725	crc = crc32(0, rd, sizeof(*rd) - 8);
 726	if (unlikely(crc != je32_to_cpu(rd->node_crc))) {
 727		JFFS2_NOTICE("node CRC failed on dnode at %#08x: read %#08x, calculated %#08x\n",
 728			     ref_offset(ref), je32_to_cpu(rd->node_crc), crc);
 729		jffs2_mark_node_obsolete(c, ref);
 730		return 0;
 731	}
 732
 733	tn = jffs2_alloc_tmp_dnode_info();
 734	if (!tn) {
 735		JFFS2_ERROR("failed to allocate tn (%zu bytes).\n", sizeof(*tn));
 736		return -ENOMEM;
 737	}
 738
 739	tn->partial_crc = 0;
 740	csize = je32_to_cpu(rd->csize);
 741
 742	/* If we've never checked the CRCs on this node, check them now */
 743	if (ref_flags(ref) == REF_UNCHECKED) {
 744
 745		/* Sanity checks */
 746		if (unlikely(je32_to_cpu(rd->offset) > je32_to_cpu(rd->isize)) ||
 747		    unlikely(PAD(je32_to_cpu(rd->csize) + sizeof(*rd)) != PAD(je32_to_cpu(rd->totlen)))) {
 748			JFFS2_WARNING("inode node header CRC is corrupted at %#08x\n", ref_offset(ref));
 749			jffs2_dbg_dump_node(c, ref_offset(ref));
 750			jffs2_mark_node_obsolete(c, ref);
 751			goto free_out;
 752		}
 753
 754		if (jffs2_is_writebuffered(c) && csize != 0) {
 755			/* At this point we are supposed to check the data CRC
 756			 * of our unchecked node. But thus far, we do not
 757			 * know whether the node is valid or obsolete. To
 758			 * figure this out, we need to walk all the nodes of
 759			 * the inode and build the inode fragtree. We don't
 760			 * want to spend time checking data of nodes which may
 761			 * later be found to be obsolete. So we put off the full
 762			 * data CRC checking until we have read all the inode
 763			 * nodes and have started building the fragtree.
 764			 *
 765			 * The fragtree is being built starting with nodes
 766			 * having the highest version number, so we'll be able
 767			 * to detect whether a node is valid (i.e., it is not
 768			 * overlapped by a node with higher version) or not.
 769			 * And we'll be able to check only those nodes, which
 770			 * are not obsolete.
 771			 *
 772			 * Of course, this optimization only makes sense in case
 773			 * of NAND flashes (or other flashes with
 774			 * !jffs2_can_mark_obsolete()), since on NOR flashes
 775			 * nodes are marked obsolete physically.
 776			 *
 777			 * Since NAND flashes (or other flashes with
 778			 * jffs2_is_writebuffered(c)) are anyway read by
 779			 * fractions of c->wbuf_pagesize, and we have just read
 780			 * the node header, it is likely that the starting part
 781			 * of the node data is also read when we read the
 782			 * header. So we don't mind to check the CRC of the
 783			 * starting part of the data of the node now, and check
 784			 * the second part later (in jffs2_check_node_data()).
 785			 * Of course, we will not need to re-read and re-check
 786			 * the NAND page which we have just read. This is why we
 787			 * read the whole NAND page at jffs2_get_inode_nodes(),
 788			 * while we needed only the node header.
 789			 */
 790			unsigned char *buf;
 791
 792			/* 'buf' will point to the start of data */
 793			buf = (unsigned char *)rd + sizeof(*rd);
 794			/* len will be the read data length */
 795			len = min_t(uint32_t, rdlen - sizeof(*rd), csize);
 796			tn->partial_crc = crc32(0, buf, len);
 797
 798			dbg_readinode("Calculates CRC (%#08x) for %d bytes, csize %d\n", tn->partial_crc, len, csize);
 799
 800			/* If we actually calculated the whole data CRC
 801			 * and it is wrong, drop the node. */
 802			if (len >= csize && unlikely(tn->partial_crc != je32_to_cpu(rd->data_crc))) {
 803				JFFS2_NOTICE("wrong data CRC in data node at 0x%08x: read %#08x, calculated %#08x.\n",
 804					ref_offset(ref), tn->partial_crc, je32_to_cpu(rd->data_crc));
 805				jffs2_mark_node_obsolete(c, ref);
 806				goto free_out;
 807			}
 808
 809		} else if (csize == 0) {
 810			/*
 811			 * We checked the header CRC. If the node has no data, adjust
 812			 * the space accounting now. For other nodes this will be done
 813			 * later either when the node is marked obsolete or when its
 814			 * data is checked.
 815			 */
 816			struct jffs2_eraseblock *jeb;
 817
 818			dbg_readinode("the node has no data.\n");
 819			jeb = &c->blocks[ref->flash_offset / c->sector_size];
 820			len = ref_totlen(c, jeb, ref);
 821
 822			spin_lock(&c->erase_completion_lock);
 823			jeb->used_size += len;
 824			jeb->unchecked_size -= len;
 825			c->used_size += len;
 826			c->unchecked_size -= len;
 827			ref->flash_offset = ref_offset(ref) | REF_NORMAL;
 828			spin_unlock(&c->erase_completion_lock);
 829		}
 830	}
 831
 832	tn->fn = jffs2_alloc_full_dnode();
 833	if (!tn->fn) {
 834		JFFS2_ERROR("alloc fn failed\n");
 835		ret = -ENOMEM;
 836		goto free_out;
 837	}
 838
 839	tn->version = je32_to_cpu(rd->version);
 840	tn->fn->ofs = je32_to_cpu(rd->offset);
 841	tn->data_crc = je32_to_cpu(rd->data_crc);
 842	tn->csize = csize;
 843	tn->fn->raw = ref;
 844	tn->overlapped = 0;
 845
 846	if (tn->version > rii->highest_version)
 847		rii->highest_version = tn->version;
 848
 849	/* There was a bug where we wrote hole nodes out with
 850	   csize/dsize swapped. Deal with it */
 851	if (rd->compr == JFFS2_COMPR_ZERO && !je32_to_cpu(rd->dsize) && csize)
 852		tn->fn->size = csize;
 853	else // normal case...
 854		tn->fn->size = je32_to_cpu(rd->dsize);
 855
 856	dbg_readinode2("dnode @%08x: ver %u, offset %#04x, dsize %#04x, csize %#04x\n",
 857		       ref_offset(ref), je32_to_cpu(rd->version),
 858		       je32_to_cpu(rd->offset), je32_to_cpu(rd->dsize), csize);
 859
 860	ret = jffs2_add_tn_to_tree(c, rii, tn);
 861
 862	if (ret) {
 863		jffs2_free_full_dnode(tn->fn);
 864	free_out:
 865		jffs2_free_tmp_dnode_info(tn);
 866		return ret;
 867	}
 868#ifdef JFFS2_DBG_READINODE2_MESSAGES
 869	dbg_readinode2("After adding ver %d:\n", je32_to_cpu(rd->version));
 870	tn = tn_first(&rii->tn_root);
 871	while (tn) {
 872		dbg_readinode2("%p: v %d r 0x%x-0x%x ov %d\n",
 873			       tn, tn->version, tn->fn->ofs,
 874			       tn->fn->ofs+tn->fn->size, tn->overlapped);
 875		tn = tn_next(tn);
 876	}
 877#endif
 878	return 0;
 879}
 880
 881/*
 882 * Helper function for jffs2_get_inode_nodes().
 883 * It is called every time an unknown node is found.
 884 *
 885 * Returns: 0 on success;
 886 * 	    negative error code on failure.
 887 */
 888static inline int read_unknown(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref, struct jffs2_unknown_node *un)
 889{
 890	/* We don't mark unknown nodes as REF_UNCHECKED */
 891	if (ref_flags(ref) == REF_UNCHECKED) {
 892		JFFS2_ERROR("REF_UNCHECKED but unknown node at %#08x\n",
 893			    ref_offset(ref));
 894		JFFS2_ERROR("Node is {%04x,%04x,%08x,%08x}. Please report this error.\n",
 895			    je16_to_cpu(un->magic), je16_to_cpu(un->nodetype),
 896			    je32_to_cpu(un->totlen), je32_to_cpu(un->hdr_crc));
 897		jffs2_mark_node_obsolete(c, ref);
 898		return 0;
 899	}
 900
 901	un->nodetype = cpu_to_je16(JFFS2_NODE_ACCURATE | je16_to_cpu(un->nodetype));
 902
 903	switch(je16_to_cpu(un->nodetype) & JFFS2_COMPAT_MASK) {
 904
 905	case JFFS2_FEATURE_INCOMPAT:
 906		JFFS2_ERROR("unknown INCOMPAT nodetype %#04X at %#08x\n",
 907			    je16_to_cpu(un->nodetype), ref_offset(ref));
 908		/* EEP */
 909		BUG();
 910		break;
 911
 912	case JFFS2_FEATURE_ROCOMPAT:
 913		JFFS2_ERROR("unknown ROCOMPAT nodetype %#04X at %#08x\n",
 914			    je16_to_cpu(un->nodetype), ref_offset(ref));
 915		BUG_ON(!(c->flags & JFFS2_SB_FLAG_RO));
 916		break;
 917
 918	case JFFS2_FEATURE_RWCOMPAT_COPY:
 919		JFFS2_NOTICE("unknown RWCOMPAT_COPY nodetype %#04X at %#08x\n",
 920			     je16_to_cpu(un->nodetype), ref_offset(ref));
 921		break;
 922
 923	case JFFS2_FEATURE_RWCOMPAT_DELETE:
 924		JFFS2_NOTICE("unknown RWCOMPAT_DELETE nodetype %#04X at %#08x\n",
 925			     je16_to_cpu(un->nodetype), ref_offset(ref));
 926		jffs2_mark_node_obsolete(c, ref);
 927		return 0;
 928	}
 929
 930	return 0;
 931}
 932
 933/*
 934 * Helper function for jffs2_get_inode_nodes().
 935 * The function detects whether more data should be read and reads it if yes.
 936 *
 937 * Returns: 0 on success;
 938 * 	    negative error code on failure.
 939 */
 940static int read_more(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref,
 941		     int needed_len, int *rdlen, unsigned char *buf)
 942{
 943	int err, to_read = needed_len - *rdlen;
 944	size_t retlen;
 945	uint32_t offs;
 946
 947	if (jffs2_is_writebuffered(c)) {
 948		int rem = to_read % c->wbuf_pagesize;
 949
 950		if (rem)
 951			to_read += c->wbuf_pagesize - rem;
 952	}
 953
 954	/* We need to read more data */
 955	offs = ref_offset(ref) + *rdlen;
 956
 957	dbg_readinode("read more %d bytes\n", to_read);
 958
 959	err = jffs2_flash_read(c, offs, to_read, &retlen, buf + *rdlen);
 960	if (err) {
 961		JFFS2_ERROR("can not read %d bytes from 0x%08x, "
 962			"error code: %d.\n", to_read, offs, err);
 963		return err;
 964	}
 965
 966	if (retlen < to_read) {
 967		JFFS2_ERROR("short read at %#08x: %zu instead of %d.\n",
 968				offs, retlen, to_read);
 969		return -EIO;
 970	}
 971
 972	*rdlen += to_read;
 973	return 0;
 974}
 975
 976/* Get tmp_dnode_info and full_dirent for all non-obsolete nodes associated
 977   with this ino. Perform a preliminary ordering on data nodes, throwing away
 978   those which are completely obsoleted by newer ones. The naïve approach we
 979   use to take of just returning them _all_ in version order will cause us to
 980   run out of memory in certain degenerate cases. */
 981static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 982				 struct jffs2_readinode_info *rii)
 983{
 984	struct jffs2_raw_node_ref *ref, *valid_ref;
 985	unsigned char *buf = NULL;
 986	union jffs2_node_union *node;
 987	size_t retlen;
 988	int len, err;
 989
 990	rii->mctime_ver = 0;
 991
 992	dbg_readinode("ino #%u\n", f->inocache->ino);
 993
 994	/* FIXME: in case of NOR and available ->point() this
 995	 * needs to be fixed. */
 996	len = sizeof(union jffs2_node_union) + c->wbuf_pagesize;
 997	buf = kmalloc(len, GFP_KERNEL);
 998	if (!buf)
 999		return -ENOMEM;
1000
1001	spin_lock(&c->erase_completion_lock);
1002	valid_ref = jffs2_first_valid_node(f->inocache->nodes);
1003	if (!valid_ref && f->inocache->ino != 1)
1004		JFFS2_WARNING("Eep. No valid nodes for ino #%u.\n", f->inocache->ino);
1005	while (valid_ref) {
1006		/* We can hold a pointer to a non-obsolete node without the spinlock,
1007		   but _obsolete_ nodes may disappear at any time, if the block
1008		   they're in gets erased. So if we mark 'ref' obsolete while we're
1009		   not holding the lock, it can go away immediately. For that reason,
1010		   we find the next valid node first, before processing 'ref'.
1011		*/
1012		ref = valid_ref;
1013		valid_ref = jffs2_first_valid_node(ref->next_in_ino);
1014		spin_unlock(&c->erase_completion_lock);
1015
1016		cond_resched();
1017
1018		/*
1019		 * At this point we don't know the type of the node we're going
1020		 * to read, so we do not know the size of its header. In order
1021		 * to minimize the amount of flash IO we assume the header is
1022		 * of size = JFFS2_MIN_NODE_HEADER.
1023		 */
1024		len = JFFS2_MIN_NODE_HEADER;
1025		if (jffs2_is_writebuffered(c)) {
1026			int end, rem;
1027
1028			/*
1029			 * We are about to read JFFS2_MIN_NODE_HEADER bytes,
1030			 * but this flash has some minimal I/O unit. It is
1031			 * possible that we'll need to read more soon, so read
1032			 * up to the next min. I/O unit, in order not to
1033			 * re-read the same min. I/O unit twice.
1034			 */
1035			end = ref_offset(ref) + len;
1036			rem = end % c->wbuf_pagesize;
1037			if (rem)
1038				end += c->wbuf_pagesize - rem;
1039			len = end - ref_offset(ref);
1040		}
1041
1042		dbg_readinode("read %d bytes at %#08x(%d).\n", len, ref_offset(ref), ref_flags(ref));
1043
1044		/* FIXME: point() */
1045		err = jffs2_flash_read(c, ref_offset(ref), len, &retlen, buf);
1046		if (err) {
1047			JFFS2_ERROR("can not read %d bytes from 0x%08x, error code: %d.\n", len, ref_offset(ref), err);
1048			goto free_out;
1049		}
1050
1051		if (retlen < len) {
1052			JFFS2_ERROR("short read at %#08x: %zu instead of %d.\n", ref_offset(ref), retlen, len);
1053			err = -EIO;
1054			goto free_out;
1055		}
1056
1057		node = (union jffs2_node_union *)buf;
1058
1059		/* No need to mask in the valid bit; it shouldn't be invalid */
1060		if (je32_to_cpu(node->u.hdr_crc) != crc32(0, node, sizeof(node->u)-4)) {
1061			JFFS2_NOTICE("Node header CRC failed at %#08x. {%04x,%04x,%08x,%08x}\n",
1062				     ref_offset(ref), je16_to_cpu(node->u.magic),
1063				     je16_to_cpu(node->u.nodetype),
1064				     je32_to_cpu(node->u.totlen),
1065				     je32_to_cpu(node->u.hdr_crc));
1066			jffs2_dbg_dump_node(c, ref_offset(ref));
1067			jffs2_mark_node_obsolete(c, ref);
1068			goto cont;
1069		}
1070		if (je16_to_cpu(node->u.magic) != JFFS2_MAGIC_BITMASK) {
1071			/* Not a JFFS2 node, whinge and move on */
1072			JFFS2_NOTICE("Wrong magic bitmask 0x%04x in node header at %#08x.\n",
1073				     je16_to_cpu(node->u.magic), ref_offset(ref));
1074			jffs2_mark_node_obsolete(c, ref);
1075			goto cont;
1076		}
1077
1078		switch (je16_to_cpu(node->u.nodetype)) {
1079
1080		case JFFS2_NODETYPE_DIRENT:
1081
1082			if (JFFS2_MIN_NODE_HEADER < sizeof(struct jffs2_raw_dirent) &&
1083			    len < sizeof(struct jffs2_raw_dirent)) {
1084				err = read_more(c, ref, sizeof(struct jffs2_raw_dirent), &len, buf);
1085				if (unlikely(err))
1086					goto free_out;
1087			}
1088
1089			err = read_direntry(c, ref, &node->d, retlen, rii);
1090			if (unlikely(err))
1091				goto free_out;
1092
1093			break;
1094
1095		case JFFS2_NODETYPE_INODE:
1096
1097			if (JFFS2_MIN_NODE_HEADER < sizeof(struct jffs2_raw_inode) &&
1098			    len < sizeof(struct jffs2_raw_inode)) {
1099				err = read_more(c, ref, sizeof(struct jffs2_raw_inode), &len, buf);
1100				if (unlikely(err))
1101					goto free_out;
1102			}
1103
1104			err = read_dnode(c, ref, &node->i, len, rii);
1105			if (unlikely(err))
1106				goto free_out;
1107
1108			break;
1109
1110		default:
1111			if (JFFS2_MIN_NODE_HEADER < sizeof(struct jffs2_unknown_node) &&
1112			    len < sizeof(struct jffs2_unknown_node)) {
1113				err = read_more(c, ref, sizeof(struct jffs2_unknown_node), &len, buf);
1114				if (unlikely(err))
1115					goto free_out;
1116			}
1117
1118			err = read_unknown(c, ref, &node->u);
1119			if (unlikely(err))
1120				goto free_out;
1121
1122		}
1123	cont:
1124		spin_lock(&c->erase_completion_lock);
1125	}
1126
1127	spin_unlock(&c->erase_completion_lock);
1128	kfree(buf);
1129
1130	f->highest_version = rii->highest_version;
1131
1132	dbg_readinode("nodes of inode #%u were read, the highest version is %u, latest_mctime %u, mctime_ver %u.\n",
1133		      f->inocache->ino, rii->highest_version, rii->latest_mctime,
1134		      rii->mctime_ver);
1135	return 0;
1136
1137 free_out:
1138	jffs2_free_tmp_dnode_info_list(&rii->tn_root);
1139	jffs2_free_full_dirent_list(rii->fds);
1140	rii->fds = NULL;
1141	kfree(buf);
1142	return err;
1143}
1144
1145static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
1146					struct jffs2_inode_info *f,
1147					struct jffs2_raw_inode *latest_node)
1148{
1149	struct jffs2_readinode_info rii;
1150	uint32_t crc, new_size;
1151	size_t retlen;
1152	int ret;
1153
1154	dbg_readinode("ino #%u pino/nlink is %d\n", f->inocache->ino,
1155		      f->inocache->pino_nlink);
1156
1157	memset(&rii, 0, sizeof(rii));
1158
1159	/* Grab all nodes relevant to this ino */
1160	ret = jffs2_get_inode_nodes(c, f, &rii);
1161
1162	if (ret) {
1163		JFFS2_ERROR("cannot read nodes for ino %u, returned error is %d\n", f->inocache->ino, ret);
1164		if (f->inocache->state == INO_STATE_READING)
1165			jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
1166		return ret;
1167	}
1168
1169	ret = jffs2_build_inode_fragtree(c, f, &rii);
1170	if (ret) {
1171		JFFS2_ERROR("Failed to build final fragtree for inode #%u: error %d\n",
1172			    f->inocache->ino, ret);
1173		if (f->inocache->state == INO_STATE_READING)
1174			jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
1175		jffs2_free_tmp_dnode_info_list(&rii.tn_root);
1176		/* FIXME: We could at least crc-check them all */
1177		if (rii.mdata_tn) {
1178			jffs2_free_full_dnode(rii.mdata_tn->fn);
1179			jffs2_free_tmp_dnode_info(rii.mdata_tn);
1180			rii.mdata_tn = NULL;
1181		}
1182		return ret;
1183	}
1184
1185	if (rii.mdata_tn) {
1186		if (rii.mdata_tn->fn->raw == rii.latest_ref) {
1187			f->metadata = rii.mdata_tn->fn;
1188			jffs2_free_tmp_dnode_info(rii.mdata_tn);
1189		} else {
1190			jffs2_kill_tn(c, rii.mdata_tn);
1191		}
1192		rii.mdata_tn = NULL;
1193	}
1194
1195	f->dents = rii.fds;
1196
1197	jffs2_dbg_fragtree_paranoia_check_nolock(f);
1198
1199	if (unlikely(!rii.latest_ref)) {
1200		/* No data nodes for this inode. */
1201		if (f->inocache->ino != 1) {
1202			JFFS2_WARNING("no data nodes found for ino #%u\n", f->inocache->ino);
1203			if (!rii.fds) {
1204				if (f->inocache->state == INO_STATE_READING)
1205					jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
1206				return -EIO;
1207			}
1208			JFFS2_NOTICE("but it has children so we fake some modes for it\n");
1209		}
1210		latest_node->mode = cpu_to_jemode(S_IFDIR|S_IRUGO|S_IWUSR|S_IXUGO);
1211		latest_node->version = cpu_to_je32(0);
1212		latest_node->atime = latest_node->ctime = latest_node->mtime = cpu_to_je32(0);
1213		latest_node->isize = cpu_to_je32(0);
1214		latest_node->gid = cpu_to_je16(0);
1215		latest_node->uid = cpu_to_je16(0);
1216		if (f->inocache->state == INO_STATE_READING)
1217			jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);
1218		return 0;
1219	}
1220
1221	ret = jffs2_flash_read(c, ref_offset(rii.latest_ref), sizeof(*latest_node), &retlen, (void *)latest_node);
1222	if (ret || retlen != sizeof(*latest_node)) {
1223		JFFS2_ERROR("failed to read from flash: error %d, %zd of %zd bytes read\n",
1224			ret, retlen, sizeof(*latest_node));
1225		/* FIXME: If this fails, there seems to be a memory leak. Find it. */
1226		return ret ? ret : -EIO;
 
 
1227	}
1228
1229	crc = crc32(0, latest_node, sizeof(*latest_node)-8);
1230	if (crc != je32_to_cpu(latest_node->node_crc)) {
1231		JFFS2_ERROR("CRC failed for read_inode of inode %u at physical location 0x%x\n",
1232			f->inocache->ino, ref_offset(rii.latest_ref));
 
 
1233		return -EIO;
1234	}
1235
1236	switch(jemode_to_cpu(latest_node->mode) & S_IFMT) {
1237	case S_IFDIR:
1238		if (rii.mctime_ver > je32_to_cpu(latest_node->version)) {
1239			/* The times in the latest_node are actually older than
1240			   mctime in the latest dirent. Cheat. */
1241			latest_node->ctime = latest_node->mtime = cpu_to_je32(rii.latest_mctime);
1242		}
1243		break;
1244
1245
1246	case S_IFREG:
1247		/* If it was a regular file, truncate it to the latest node's isize */
1248		new_size = jffs2_truncate_fragtree(c, &f->fragtree, je32_to_cpu(latest_node->isize));
1249		if (new_size != je32_to_cpu(latest_node->isize)) {
1250			JFFS2_WARNING("Truncating ino #%u to %d bytes failed because it only had %d bytes to start with!\n",
1251				      f->inocache->ino, je32_to_cpu(latest_node->isize), new_size);
1252			latest_node->isize = cpu_to_je32(new_size);
1253		}
1254		break;
1255
1256	case S_IFLNK:
1257		/* Hack to work around broken isize in old symlink code.
1258		   Remove this when dwmw2 comes to his senses and stops
1259		   symlinks from being an entirely gratuitous special
1260		   case. */
1261		if (!je32_to_cpu(latest_node->isize))
1262			latest_node->isize = latest_node->dsize;
1263
1264		if (f->inocache->state != INO_STATE_CHECKING) {
1265			/* Symlink's inode data is the target path. Read it and
1266			 * keep in RAM to facilitate quick follow symlink
1267			 * operation. */
1268			uint32_t csize = je32_to_cpu(latest_node->csize);
1269			if (csize > JFFS2_MAX_NAME_LEN)
1270				return -ENAMETOOLONG;
1271			f->target = kmalloc(csize + 1, GFP_KERNEL);
1272			if (!f->target) {
1273				JFFS2_ERROR("can't allocate %u bytes of memory for the symlink target path cache\n", csize);
 
 
1274				return -ENOMEM;
1275			}
1276
1277			ret = jffs2_flash_read(c, ref_offset(rii.latest_ref) + sizeof(*latest_node),
1278					       csize, &retlen, (char *)f->target);
1279
1280			if (ret || retlen != csize) {
1281				if (retlen != csize)
1282					ret = -EIO;
1283				kfree(f->target);
1284				f->target = NULL;
 
 
1285				return ret;
1286			}
1287
1288			f->target[csize] = '\0';
1289			dbg_readinode("symlink's target '%s' cached\n", f->target);
1290		}
1291
1292		fallthrough;
1293
1294	case S_IFBLK:
1295	case S_IFCHR:
1296		/* Certain inode types should have only one data node, and it's
1297		   kept as the metadata node */
1298		if (f->metadata) {
1299			JFFS2_ERROR("Argh. Special inode #%u with mode 0%o had metadata node\n",
1300			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
 
 
1301			return -EIO;
1302		}
1303		if (!frag_first(&f->fragtree)) {
1304			JFFS2_ERROR("Argh. Special inode #%u with mode 0%o has no fragments\n",
1305			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
 
 
1306			return -EIO;
1307		}
1308		/* ASSERT: f->fraglist != NULL */
1309		if (frag_next(frag_first(&f->fragtree))) {
1310			JFFS2_ERROR("Argh. Special inode #%u with mode 0x%x had more than one node\n",
1311			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
1312			/* FIXME: Deal with it - check crc32, check for duplicate node, check times and discard the older one */
 
 
1313			return -EIO;
1314		}
1315		/* OK. We're happy */
1316		f->metadata = frag_first(&f->fragtree)->node;
1317		jffs2_free_node_frag(frag_first(&f->fragtree));
1318		f->fragtree = RB_ROOT;
1319		break;
1320	}
1321	if (f->inocache->state == INO_STATE_READING)
1322		jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);
1323
1324	return 0;
1325}
1326
1327/* Scan the list of all nodes present for this ino, build map of versions, etc. */
1328int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
1329			uint32_t ino, struct jffs2_raw_inode *latest_node)
1330{
1331	dbg_readinode("read inode #%u\n", ino);
1332
1333 retry_inocache:
1334	spin_lock(&c->inocache_lock);
1335	f->inocache = jffs2_get_ino_cache(c, ino);
1336
1337	if (f->inocache) {
1338		/* Check its state. We may need to wait before we can use it */
1339		switch(f->inocache->state) {
1340		case INO_STATE_UNCHECKED:
1341		case INO_STATE_CHECKEDABSENT:
1342			f->inocache->state = INO_STATE_READING;
1343			break;
1344
1345		case INO_STATE_CHECKING:
1346		case INO_STATE_GC:
1347			/* If it's in either of these states, we need
1348			   to wait for whoever's got it to finish and
1349			   put it back. */
1350			dbg_readinode("waiting for ino #%u in state %d\n", ino, f->inocache->state);
1351			sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
1352			goto retry_inocache;
1353
1354		case INO_STATE_READING:
1355		case INO_STATE_PRESENT:
1356			/* Eep. This should never happen. It can
1357			happen if Linux calls read_inode() again
1358			before clear_inode() has finished though. */
1359			JFFS2_ERROR("Eep. Trying to read_inode #%u when it's already in state %d!\n", ino, f->inocache->state);
1360			/* Fail. That's probably better than allowing it to succeed */
1361			f->inocache = NULL;
1362			break;
1363
1364		default:
1365			BUG();
1366		}
1367	}
1368	spin_unlock(&c->inocache_lock);
1369
1370	if (!f->inocache && ino == 1) {
1371		/* Special case - no root inode on medium */
1372		f->inocache = jffs2_alloc_inode_cache();
1373		if (!f->inocache) {
1374			JFFS2_ERROR("cannot allocate inocache for root inode\n");
1375			return -ENOMEM;
1376		}
1377		dbg_readinode("creating inocache for root inode\n");
1378		memset(f->inocache, 0, sizeof(struct jffs2_inode_cache));
1379		f->inocache->ino = f->inocache->pino_nlink = 1;
1380		f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache;
1381		f->inocache->state = INO_STATE_READING;
1382		jffs2_add_ino_cache(c, f->inocache);
1383	}
1384	if (!f->inocache) {
1385		JFFS2_ERROR("requested to read a nonexistent ino %u\n", ino);
1386		return -ENOENT;
1387	}
1388
1389	return jffs2_do_read_inode_internal(c, f, latest_node);
1390}
1391
1392int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
1393{
1394	struct jffs2_raw_inode n;
1395	struct jffs2_inode_info *f = kzalloc(sizeof(*f), GFP_KERNEL);
1396	int ret;
1397
1398	if (!f)
1399		return -ENOMEM;
1400
1401	mutex_init(&f->sem);
1402	mutex_lock(&f->sem);
1403	f->inocache = ic;
1404
1405	ret = jffs2_do_read_inode_internal(c, f, &n);
1406	mutex_unlock(&f->sem);
1407	jffs2_do_clear_inode(c, f);
1408	jffs2_xattr_do_crccheck_inode(c, ic);
 
1409	kfree (f);
1410	return ret;
1411}
1412
1413void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f)
1414{
1415	struct jffs2_full_dirent *fd, *fds;
1416	int deleted;
1417
1418	jffs2_xattr_delete_inode(c, f->inocache);
1419	mutex_lock(&f->sem);
1420	deleted = f->inocache && !f->inocache->pino_nlink;
1421
1422	if (f->inocache && f->inocache->state != INO_STATE_CHECKING)
1423		jffs2_set_inocache_state(c, f->inocache, INO_STATE_CLEARING);
1424
1425	if (f->metadata) {
1426		if (deleted)
1427			jffs2_mark_node_obsolete(c, f->metadata->raw);
1428		jffs2_free_full_dnode(f->metadata);
1429	}
1430
1431	jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL);
 
 
 
 
 
1432
1433	fds = f->dents;
1434	while(fds) {
1435		fd = fds;
1436		fds = fd->next;
1437		jffs2_free_full_dirent(fd);
1438	}
1439
1440	if (f->inocache && f->inocache->state != INO_STATE_CHECKING) {
1441		jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
1442		if (f->inocache->nodes == (void *)f->inocache)
1443			jffs2_del_ino_cache(c, f->inocache);
1444	}
1445
1446	mutex_unlock(&f->sem);
1447}