fs/jffs2/readinode.c - LeafOS-Devices/android_kernel_realme_mt6785 - Gitiles

 /*
  * JFFS2 -- Journalling Flash File System, Version 2.
  *
  * Copyright (C) 2001-2003 Red Hat, Inc.
  *
  * Created by David Woodhouse <dwmw2@infradead.org>
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
  * $Id: readinode.c,v 1.126 2005/07/17 06:56:21 dedekind Exp $
  *
  */

 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/crc32.h>
 #include <linux/pagemap.h>
 #include <linux/mtd/mtd.h>
 #include <linux/compiler.h>
 #include "nodelist.h"

 static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *list, struct jffs2_node_frag *newfrag);

 static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c, struct jffs2_node_frag *this)
 {
 	if (this->node) {
 		this->node->frags--;
 		if (!this->node->frags) {
 			/* The node has no valid frags left. It's totally obsoleted */
 			D2(printk(KERN_DEBUG "Marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
 				  ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size));
 			jffs2_mark_node_obsolete(c, this->node->raw);
 			jffs2_free_full_dnode(this->node);
 		} else {
 			D2(printk(KERN_DEBUG "Marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
 				  ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size,
 				  this->node->frags));
 			mark_ref_normal(this->node->raw);
 		}

 	}
 	jffs2_free_node_frag(this);
 }

 /* Given an inode, probably with existing list of fragments, add the new node
  * to the fragment list.
  */
 int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
 {
 	int ret;
 	struct jffs2_node_frag *newfrag;

 	D1(printk(KERN_DEBUG "jffs2_add_full_dnode_to_inode(ino #%u, f %p, fn %p)\n", f->inocache->ino, f, fn));

 	if (unlikely(!fn->size))
 		return 0;

 	newfrag = jffs2_alloc_node_frag();
 	if (unlikely(!newfrag))
 		return -ENOMEM;

 	D2(printk(KERN_DEBUG "adding node %04x-%04x @0x%08x on flash, newfrag *%p\n",
 		  fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag));

 	newfrag->ofs = fn->ofs;
 	newfrag->size = fn->size;
 	newfrag->node = fn;
 	newfrag->node->frags = 1;

 	ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
 	if (ret)
 		return ret;

 	/* If we now share a page with other nodes, mark either previous
 	   or next node REF_NORMAL, as appropriate.  */
 	if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
 		struct jffs2_node_frag *prev = frag_prev(newfrag);

 		mark_ref_normal(fn->raw);
 		/* If we don't start at zero there's _always_ a previous */
 		if (prev->node)
 			mark_ref_normal(prev->node->raw);
 	}

 	if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
 		struct jffs2_node_frag *next = frag_next(newfrag);

 		if (next) {
 			mark_ref_normal(fn->raw);
 			if (next->node)
 				mark_ref_normal(next->node->raw);
 		}
 	}
 	D2(jffs2_dbg_fragtree_paranoia_check(f));
 	D2(jffs2_dbg_dump_fragtree(f));
 	return 0;
 }

 /* Doesn't set inode->i_size */
 static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *list, struct jffs2_node_frag *newfrag)
 {
 	struct jffs2_node_frag *this;
 	uint32_t lastend;

 	/* Skip all the nodes which are completed before this one starts */
 	this = jffs2_lookup_node_frag(list, newfrag->node->ofs);

 	if (this) {
 		D2(printk(KERN_DEBUG "j_a_f_d_t_f: Lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
 			  this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this));
 		lastend = this->ofs + this->size;
 	} else {
 		D2(printk(KERN_DEBUG "j_a_f_d_t_f: Lookup gave no frag\n"));
 		lastend = 0;
 	}

 	/* See if we ran off the end of the list */
 	if (lastend <= newfrag->ofs) {
 		/* We did */

 		/* Check if 'this' node was on the same page as the new node.
 		   If so, both 'this' and the new node get marked REF_NORMAL so
 		   the GC can take a look.
 		*/
 		if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
 			if (this->node)
 				mark_ref_normal(this->node->raw);
 			mark_ref_normal(newfrag->node->raw);
 		}

 		if (lastend < newfrag->node->ofs) {
 			/* ... and we need to put a hole in before the new node */
 			struct jffs2_node_frag *holefrag = jffs2_alloc_node_frag();
 			if (!holefrag) {
 				jffs2_free_node_frag(newfrag);
 				return -ENOMEM;
 			}
 			holefrag->ofs = lastend;
 			holefrag->size = newfrag->node->ofs - lastend;
 			holefrag->node = NULL;
 			if (this) {
 				/* By definition, the 'this' node has no right-hand child,
 				   because there are no frags with offset greater than it.
 				   So that's where we want to put the hole */
 				D2(printk(KERN_DEBUG "Adding hole frag (%p) on right of node at (%p)\n", holefrag, this));
 				rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
 			} else {
 				D2(printk(KERN_DEBUG "Adding hole frag (%p) at root of tree\n", holefrag));
 				rb_link_node(&holefrag->rb, NULL, &list->rb_node);
 			}
 			rb_insert_color(&holefrag->rb, list);
 			this = holefrag;
 		}
 		if (this) {
 			/* By definition, the 'this' node has no right-hand child,
 			   because there are no frags with offset greater than it.
 			   So that's where we want to put the hole */
 			D2(printk(KERN_DEBUG "Adding new frag (%p) on right of node at (%p)\n", newfrag, this));
 			rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
 		} else {
 			D2(printk(KERN_DEBUG "Adding new frag (%p) at root of tree\n", newfrag));
 			rb_link_node(&newfrag->rb, NULL, &list->rb_node);
 		}
 		rb_insert_color(&newfrag->rb, list);
 		return 0;
 	}

 	D2(printk(KERN_DEBUG "j_a_f_d_t_f: dealing with frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
 		  this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this));

 	/* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
 	 * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
 	 */
 	if (newfrag->ofs > this->ofs) {
 		/* This node isn't completely obsoleted. The start of it remains valid */

 		/* Mark the new node and the partially covered node REF_NORMAL -- let
 		   the GC take a look at them */
 		mark_ref_normal(newfrag->node->raw);
 		if (this->node)
 			mark_ref_normal(this->node->raw);

 		if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
 			/* The new node splits 'this' frag into two */
 			struct jffs2_node_frag *newfrag2 = jffs2_alloc_node_frag();
 			if (!newfrag2) {
 				jffs2_free_node_frag(newfrag);
 				return -ENOMEM;
 			}
 			D2(printk(KERN_DEBUG "split old frag 0x%04x-0x%04x -->", this->ofs, this->ofs+this->size);
 			if (this->node)
 				printk("phys 0x%08x\n", ref_offset(this->node->raw));
 			else
 				printk("hole\n");
 			   )

 			/* New second frag pointing to this's node */
 			newfrag2->ofs = newfrag->ofs + newfrag->size;
 			newfrag2->size = (this->ofs+this->size) - newfrag2->ofs;
 			newfrag2->node = this->node;
 			if (this->node)
 				this->node->frags++;

 			/* Adjust size of original 'this' */
 			this->size = newfrag->ofs - this->ofs;

 			/* Now, we know there's no node with offset
 			   greater than this->ofs but smaller than
 			   newfrag2->ofs or newfrag->ofs, for obvious
 			   reasons. So we can do a tree insert from
 			   'this' to insert newfrag, and a tree insert
 			   from newfrag to insert newfrag2. */
 			jffs2_fragtree_insert(newfrag, this);
 			rb_insert_color(&newfrag->rb, list);

 			jffs2_fragtree_insert(newfrag2, newfrag);
 			rb_insert_color(&newfrag2->rb, list);

 			return 0;
 		}
 		/* New node just reduces 'this' frag in size, doesn't split it */
 		this->size = newfrag->ofs - this->ofs;

 		/* Again, we know it lives down here in the tree */
 		jffs2_fragtree_insert(newfrag, this);
 		rb_insert_color(&newfrag->rb, list);
 	} else {
 		/* New frag starts at the same point as 'this' used to. Replace
 		   it in the tree without doing a delete and insertion */
 		D2(printk(KERN_DEBUG "Inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
 			  newfrag, newfrag->ofs, newfrag->ofs+newfrag->size,
 			  this, this->ofs, this->ofs+this->size));

 		rb_replace_node(&this->rb, &newfrag->rb, list);

 		if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
 			D2(printk(KERN_DEBUG "Obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size));
 			jffs2_obsolete_node_frag(c, this);
 		} else {
 			this->ofs += newfrag->size;
 			this->size -= newfrag->size;

 			jffs2_fragtree_insert(this, newfrag);
 			rb_insert_color(&this->rb, list);
 			return 0;
 		}
 	}
 	/* OK, now we have newfrag added in the correct place in the tree, but
 	   frag_next(newfrag) may be a fragment which is overlapped by it
 	*/
 	while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
 		/* 'this' frag is obsoleted completely. */
 		D2(printk(KERN_DEBUG "Obsoleting node frag %p (%x-%x) and removing from tree\n", this, this->ofs, this->ofs+this->size));
 		rb_erase(&this->rb, list);
 		jffs2_obsolete_node_frag(c, this);
 	}
 	/* Now we're pointing at the first frag which isn't totally obsoleted by
 	   the new frag */

 	if (!this || newfrag->ofs + newfrag->size == this->ofs) {
 		return 0;
 	}
 	/* Still some overlap but we don't need to move it in the tree */
 	this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
 	this->ofs = newfrag->ofs + newfrag->size;

 	/* And mark them REF_NORMAL so the GC takes a look at them */
 	if (this->node)
 		mark_ref_normal(this->node->raw);
 	mark_ref_normal(newfrag->node->raw);

 	return 0;
 }

 void jffs2_truncate_fraglist (struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
 {
 	struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);

 	D1(printk(KERN_DEBUG "Truncating fraglist to 0x%08x bytes\n", size));

 	/* We know frag->ofs <= size. That's what lookup does for us */
 	if (frag && frag->ofs != size) {
 		if (frag->ofs+frag->size >= size) {
 			D1(printk(KERN_DEBUG "Truncating frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
 			frag->size = size - frag->ofs;
 		}
 		frag = frag_next(frag);
 	}
 	while (frag && frag->ofs >= size) {
 		struct jffs2_node_frag *next = frag_next(frag);

 		D1(printk(KERN_DEBUG "Removing frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
 		frag_erase(frag, list);
 		jffs2_obsolete_node_frag(c, frag);
 		frag = next;
 	}
 }

 /* Scan the list of all nodes present for this ino, build map of versions, etc. */

 static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
 					struct jffs2_inode_info *f,
 					struct jffs2_raw_inode *latest_node);

 int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 			uint32_t ino, struct jffs2_raw_inode *latest_node)
 {
 	D2(printk(KERN_DEBUG "jffs2_do_read_inode(): getting inocache\n"));

  retry_inocache:
 	spin_lock(&c->inocache_lock);
 	f->inocache = jffs2_get_ino_cache(c, ino);

 	D2(printk(KERN_DEBUG "jffs2_do_read_inode(): Got inocache at %p\n", f->inocache));

 	if (f->inocache) {
 		/* Check its state. We may need to wait before we can use it */
 		switch(f->inocache->state) {
 		case INO_STATE_UNCHECKED:
 		case INO_STATE_CHECKEDABSENT:
 			f->inocache->state = INO_STATE_READING;
 			break;

 		case INO_STATE_CHECKING:
 		case INO_STATE_GC:
 			/* If it's in either of these states, we need
 			   to wait for whoever's got it to finish and
 			   put it back. */
 			D1(printk(KERN_DEBUG "jffs2_get_ino_cache_read waiting for ino #%u in state %d\n",
 				  ino, f->inocache->state));
 			sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
 			goto retry_inocache;

 		case INO_STATE_READING:
 		case INO_STATE_PRESENT:
 			/* Eep. This should never happen. It can
 			happen if Linux calls read_inode() again
 			before clear_inode() has finished though. */
 			printk(KERN_WARNING "Eep. Trying to read_inode #%u when it's already in state %d!\n", ino, f->inocache->state);
 			/* Fail. That's probably better than allowing it to succeed */
 			f->inocache = NULL;
 			break;

 		default:
 			BUG();
 		}
 	}
 	spin_unlock(&c->inocache_lock);

 	if (!f->inocache && ino == 1) {
 		/* Special case - no root inode on medium */
 		f->inocache = jffs2_alloc_inode_cache();
 		if (!f->inocache) {
 			printk(KERN_CRIT "jffs2_do_read_inode(): Cannot allocate inocache for root inode\n");
 			return -ENOMEM;
 		}
 		D1(printk(KERN_DEBUG "jffs2_do_read_inode(): Creating inocache for root inode\n"));
 		memset(f->inocache, 0, sizeof(struct jffs2_inode_cache));
 		f->inocache->ino = f->inocache->nlink = 1;
 		f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache;
 		f->inocache->state = INO_STATE_READING;
 		jffs2_add_ino_cache(c, f->inocache);
 	}
 	if (!f->inocache) {
 		printk(KERN_WARNING "jffs2_do_read_inode() on nonexistent ino %u\n", ino);
 		return -ENOENT;
 	}

 	return jffs2_do_read_inode_internal(c, f, latest_node);
 }

 int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 {
 	struct jffs2_raw_inode n;
 	struct jffs2_inode_info *f = kmalloc(sizeof(*f), GFP_KERNEL);
 	int ret;

 	if (!f)
 		return -ENOMEM;

 	memset(f, 0, sizeof(*f));
 	init_MUTEX_LOCKED(&f->sem);
 	f->inocache = ic;

 	ret = jffs2_do_read_inode_internal(c, f, &n);
 	if (!ret) {
 		up(&f->sem);
 		jffs2_do_clear_inode(c, f);
 	}
 	kfree (f);
 	return ret;
 }

 static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
 					struct jffs2_inode_info *f,
 					struct jffs2_raw_inode *latest_node)
 {
 	struct jffs2_tmp_dnode_info *tn = NULL;
 	struct rb_root tn_list;
 	struct rb_node *rb, *repl_rb;
 	struct jffs2_full_dirent *fd_list;
 	struct jffs2_full_dnode *fn = NULL;
 	uint32_t crc;
 	uint32_t latest_mctime, mctime_ver;
 	uint32_t mdata_ver = 0;
 	size_t retlen;
 	int ret;

 	D1(printk(KERN_DEBUG "jffs2_do_read_inode_internal(): ino #%u nlink is %d\n", f->inocache->ino, f->inocache->nlink));

 	/* Grab all nodes relevant to this ino */
 	ret = jffs2_get_inode_nodes(c, f, &tn_list, &fd_list, &f->highest_version, &latest_mctime, &mctime_ver);

 	if (ret) {
 		printk(KERN_CRIT "jffs2_get_inode_nodes() for ino %u returned %d\n", f->inocache->ino, ret);
 		if (f->inocache->state == INO_STATE_READING)
 			jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
 		return ret;
 	}
 	f->dents = fd_list;

 	rb = rb_first(&tn_list);

 	while (rb) {
 		tn = rb_entry(rb, struct jffs2_tmp_dnode_info, rb);
 		fn = tn->fn;

 		if (f->metadata) {
 			if (likely(tn->version >= mdata_ver)) {
 				D1(printk(KERN_DEBUG "Obsoleting old metadata at 0x%08x\n", ref_offset(f->metadata->raw)));
 				jffs2_mark_node_obsolete(c, f->metadata->raw);
 				jffs2_free_full_dnode(f->metadata);
 				f->metadata = NULL;

 				mdata_ver = 0;
 			} else {
 				/* This should never happen. */
 				printk(KERN_WARNING "Er. New metadata at 0x%08x with ver %d is actually older than previous ver %d at 0x%08x\n",
 					  ref_offset(fn->raw), tn->version, mdata_ver, ref_offset(f->metadata->raw));
 				jffs2_mark_node_obsolete(c, fn->raw);
 				jffs2_free_full_dnode(fn);
 				/* Fill in latest_node from the metadata, not this one we're about to free... */
 				fn = f->metadata;
 				goto next_tn;
 			}
 		}

 		if (fn->size) {
 			jffs2_add_full_dnode_to_inode(c, f, fn);
 		} else {
 			/* Zero-sized node at end of version list. Just a metadata update */
 			D1(printk(KERN_DEBUG "metadata @%08x: ver %d\n", ref_offset(fn->raw), tn->version));
 			f->metadata = fn;
 			mdata_ver = tn->version;
 		}
 	next_tn:
 		BUG_ON(rb->rb_left);
 		if (rb->rb_parent && rb->rb_parent->rb_left == rb) {
 			/* We were then left-hand child of our parent. We need
 			   to move our own right-hand child into our place. */
 			repl_rb = rb->rb_right;
 			if (repl_rb)
 				repl_rb->rb_parent = rb->rb_parent;
 		} else
 			repl_rb = NULL;

 		rb = rb_next(rb);

 		/* Remove the spent tn from the tree; don't bother rebalancing
 		   but put our right-hand child in our own place. */
 		if (tn->rb.rb_parent) {
 			if (tn->rb.rb_parent->rb_left == &tn->rb)
 				tn->rb.rb_parent->rb_left = repl_rb;
 			else if (tn->rb.rb_parent->rb_right == &tn->rb)
 				tn->rb.rb_parent->rb_right = repl_rb;
 			else BUG();
 		} else if (tn->rb.rb_right)
 			tn->rb.rb_right->rb_parent = NULL;

 		jffs2_free_tmp_dnode_info(tn);
 	}
 	jffs2_dbg_fragtree_paranoia_check(f);

 	if (!fn) {
 		/* No data nodes for this inode. */
 		if (f->inocache->ino != 1) {
 			printk(KERN_WARNING "jffs2_do_read_inode(): No data nodes found for ino #%u\n", f->inocache->ino);
 			if (!fd_list) {
 				if (f->inocache->state == INO_STATE_READING)
 					jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
 				return -EIO;
 			}
 			printk(KERN_WARNING "jffs2_do_read_inode(): But it has children so we fake some modes for it\n");
 		}
 		latest_node->mode = cpu_to_jemode(S_IFDIR|S_IRUGO|S_IWUSR|S_IXUGO);
 		latest_node->version = cpu_to_je32(0);
 		latest_node->atime = latest_node->ctime = latest_node->mtime = cpu_to_je32(0);
 		latest_node->isize = cpu_to_je32(0);
 		latest_node->gid = cpu_to_je16(0);
 		latest_node->uid = cpu_to_je16(0);
 		if (f->inocache->state == INO_STATE_READING)
 			jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);
 		return 0;
 	}

 	ret = jffs2_flash_read(c, ref_offset(fn->raw), sizeof(*latest_node), &retlen, (void *)latest_node);
 	if (ret || retlen != sizeof(*latest_node)) {
 		printk(KERN_NOTICE "MTD read in jffs2_do_read_inode() failed: Returned %d, %zd of %zd bytes read\n",
 		       ret, retlen, sizeof(*latest_node));
 		/* FIXME: If this fails, there seems to be a memory leak. Find it. */
 		up(&f->sem);
 		jffs2_do_clear_inode(c, f);
 		return ret?ret:-EIO;
 	}

 	crc = crc32(0, latest_node, sizeof(*latest_node)-8);
 	if (crc != je32_to_cpu(latest_node->node_crc)) {
 		printk(KERN_NOTICE "CRC failed for read_inode of inode %u at physical location 0x%x\n", f->inocache->ino, ref_offset(fn->raw));
 		up(&f->sem);
 		jffs2_do_clear_inode(c, f);
 		return -EIO;
 	}

 	switch(jemode_to_cpu(latest_node->mode) & S_IFMT) {
 	case S_IFDIR:
 		if (mctime_ver > je32_to_cpu(latest_node->version)) {
 			/* The times in the latest_node are actually older than
 			   mctime in the latest dirent. Cheat. */
 			latest_node->ctime = latest_node->mtime = cpu_to_je32(latest_mctime);
 		}
 		break;


 	case S_IFREG:
 		/* If it was a regular file, truncate it to the latest node's isize */
 		jffs2_truncate_fraglist(c, &f->fragtree, je32_to_cpu(latest_node->isize));
 		break;

 	case S_IFLNK:
 		/* Hack to work around broken isize in old symlink code.
 		   Remove this when dwmw2 comes to his senses and stops
 		   symlinks from being an entirely gratuitous special
 		   case. */
 		if (!je32_to_cpu(latest_node->isize))
 			latest_node->isize = latest_node->dsize;

 		if (f->inocache->state != INO_STATE_CHECKING) {
 			/* Symlink's inode data is the target path. Read it and
 			 * keep in RAM to facilitate quick follow symlink operation.
 			 * We use f->dents field to store the target path, which
 			 * is somewhat ugly. */
 			f->dents = kmalloc(je32_to_cpu(latest_node->csize) + 1, GFP_KERNEL);
 			if (!f->dents) {
 				printk(KERN_WARNING "Can't allocate %d bytes of memory "
 						"for the symlink target path cache\n",
 						je32_to_cpu(latest_node->csize));
 				up(&f->sem);
 				jffs2_do_clear_inode(c, f);
 				return -ENOMEM;
 			}

 			ret = jffs2_flash_read(c, ref_offset(fn->raw) + sizeof(*latest_node),
 						je32_to_cpu(latest_node->csize), &retlen, (char *)f->dents);

 			if (ret  || retlen != je32_to_cpu(latest_node->csize)) {
 				if (retlen != je32_to_cpu(latest_node->csize))
 					ret = -EIO;
 				kfree(f->dents);
 				f->dents = NULL;
 				up(&f->sem);
 				jffs2_do_clear_inode(c, f);
 				return -ret;
 			}

 			((char *)f->dents)[je32_to_cpu(latest_node->csize)] = '\0';
 			D1(printk(KERN_DEBUG "jffs2_do_read_inode(): symlink's target '%s' cached\n",
 						(char *)f->dents));
 		}

 		/* fall through... */

 	case S_IFBLK:
 	case S_IFCHR:
 		/* Certain inode types should have only one data node, and it's
 		   kept as the metadata node */
 		if (f->metadata) {
 			printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o had metadata node\n",
 			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
 			up(&f->sem);
 			jffs2_do_clear_inode(c, f);
 			return -EIO;
 		}
 		if (!frag_first(&f->fragtree)) {
 			printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o has no fragments\n",
 			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
 			up(&f->sem);
 			jffs2_do_clear_inode(c, f);
 			return -EIO;
 		}
 		/* ASSERT: f->fraglist != NULL */
 		if (frag_next(frag_first(&f->fragtree))) {
 			printk(KERN_WARNING "Argh. Special inode #%u with mode 0x%x had more than one node\n",
 			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
 			/* FIXME: Deal with it - check crc32, check for duplicate node, check times and discard the older one */
 			up(&f->sem);
 			jffs2_do_clear_inode(c, f);
 			return -EIO;
 		}
 		/* OK. We're happy */
 		f->metadata = frag_first(&f->fragtree)->node;
 		jffs2_free_node_frag(frag_first(&f->fragtree));
 		f->fragtree = RB_ROOT;
 		break;
 	}
 	if (f->inocache->state == INO_STATE_READING)
 		jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);

 	return 0;
 }

 void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f)
 {
 	struct jffs2_full_dirent *fd, *fds;
 	int deleted;

 	down(&f->sem);
 	deleted = f->inocache && !f->inocache->nlink;

 	if (f->inocache && f->inocache->state != INO_STATE_CHECKING)
 		jffs2_set_inocache_state(c, f->inocache, INO_STATE_CLEARING);

 	if (f->metadata) {
 		if (deleted)
 			jffs2_mark_node_obsolete(c, f->metadata->raw);
 		jffs2_free_full_dnode(f->metadata);
 	}

 	jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL);

 	/* For symlink inodes we us f->dents to store the target path name */
 	if (S_ISLNK(OFNI_EDONI_2SFFJ(f)->i_mode)) {
 		if (f->dents) {
 			kfree(f->dents);
 			f->dents = NULL;
 		}
 	} else {
 		fds = f->dents;

 		while(fds) {
 			fd = fds;
 			fds = fd->next;
 			jffs2_free_full_dirent(fd);
 		}
 	}

 	if (f->inocache && f->inocache->state != INO_STATE_CHECKING) {
 		jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
 		if (f->inocache->nodes == (void *)f->inocache)
 			jffs2_del_ino_cache(c, f->inocache);
 	}

 	up(&f->sem);
 }
	/*
	* JFFS2 -- Journalling Flash File System, Version 2.
	*
	* Copyright (C) 2001-2003 Red Hat, Inc.
	*
	* Created by David Woodhouse <dwmw2@infradead.org>
	*
	* For licensing information, see the file 'LICENCE' in this directory.
	*
	* $Id: readinode.c,v 1.126 2005/07/17 06:56:21 dedekind Exp $
	*
	*/

	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/fs.h>
	#include <linux/crc32.h>
	#include <linux/pagemap.h>
	#include <linux/mtd/mtd.h>
	#include <linux/compiler.h>
	#include "nodelist.h"

	static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info c, struct rb_root list, struct jffs2_node_frag *newfrag);

	static void jffs2_obsolete_node_frag(struct jffs2_sb_info c, struct jffs2_node_frag this)
	{
	if (this->node) {
	this->node->frags--;
	if (!this->node->frags) {
	/* The node has no valid frags left. It's totally obsoleted */
	D2(printk(KERN_DEBUG "Marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
	ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size));
	jffs2_mark_node_obsolete(c, this->node->raw);
	jffs2_free_full_dnode(this->node);
	} else {
	D2(printk(KERN_DEBUG "Marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
	ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size,
	this->node->frags));
	mark_ref_normal(this->node->raw);
	}

	}
	jffs2_free_node_frag(this);
	}

	/* Given an inode, probably with existing list of fragments, add the new node
	* to the fragment list.
	*/
	int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info c, struct jffs2_inode_info f, struct jffs2_full_dnode *fn)
	{
	int ret;
	struct jffs2_node_frag *newfrag;

	D1(printk(KERN_DEBUG "jffs2_add_full_dnode_to_inode(ino #%u, f %p, fn %p)\n", f->inocache->ino, f, fn));

	if (unlikely(!fn->size))
	return 0;

	newfrag = jffs2_alloc_node_frag();
	if (unlikely(!newfrag))
	return -ENOMEM;

	D2(printk(KERN_DEBUG "adding node %04x-%04x @0x%08x on flash, newfrag *%p\n",
	fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag));

	newfrag->ofs = fn->ofs;
	newfrag->size = fn->size;
	newfrag->node = fn;
	newfrag->node->frags = 1;

	ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
	if (ret)
	return ret;

	/* If we now share a page with other nodes, mark either previous
	or next node REF_NORMAL, as appropriate. */
	if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
	struct jffs2_node_frag *prev = frag_prev(newfrag);

	mark_ref_normal(fn->raw);
	/* If we don't start at zero there's _always_ a previous */
	if (prev->node)
	mark_ref_normal(prev->node->raw);
	}

	if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
	struct jffs2_node_frag *next = frag_next(newfrag);

	if (next) {
	mark_ref_normal(fn->raw);
	if (next->node)
	mark_ref_normal(next->node->raw);
	}
	}
	D2(jffs2_dbg_fragtree_paranoia_check(f));
	D2(jffs2_dbg_dump_fragtree(f));
	return 0;
	}

	/* Doesn't set inode->i_size */
	static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info c, struct rb_root list, struct jffs2_node_frag *newfrag)
	{
	struct jffs2_node_frag *this;
	uint32_t lastend;

	/* Skip all the nodes which are completed before this one starts */
	this = jffs2_lookup_node_frag(list, newfrag->node->ofs);

	if (this) {
	D2(printk(KERN_DEBUG "j_a_f_d_t_f: Lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
	this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this));
	lastend = this->ofs + this->size;
	} else {
	D2(printk(KERN_DEBUG "j_a_f_d_t_f: Lookup gave no frag\n"));
	lastend = 0;
	}

	/* See if we ran off the end of the list */
	if (lastend <= newfrag->ofs) {
	/* We did */

	/* Check if 'this' node was on the same page as the new node.
	If so, both 'this' and the new node get marked REF_NORMAL so
	the GC can take a look.
	*/
	if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
	if (this->node)
	mark_ref_normal(this->node->raw);
	mark_ref_normal(newfrag->node->raw);
	}

	if (lastend < newfrag->node->ofs) {
	/* ... and we need to put a hole in before the new node */
	struct jffs2_node_frag *holefrag = jffs2_alloc_node_frag();
	if (!holefrag) {
	jffs2_free_node_frag(newfrag);
	return -ENOMEM;
	}
	holefrag->ofs = lastend;
	holefrag->size = newfrag->node->ofs - lastend;
	holefrag->node = NULL;
	if (this) {
	/* By definition, the 'this' node has no right-hand child,
	because there are no frags with offset greater than it.
	So that's where we want to put the hole */
	D2(printk(KERN_DEBUG "Adding hole frag (%p) on right of node at (%p)\n", holefrag, this));
	rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
	} else {
	D2(printk(KERN_DEBUG "Adding hole frag (%p) at root of tree\n", holefrag));
	rb_link_node(&holefrag->rb, NULL, &list->rb_node);
	}
	rb_insert_color(&holefrag->rb, list);
	this = holefrag;
	}
	if (this) {
	/* By definition, the 'this' node has no right-hand child,
	because there are no frags with offset greater than it.
	So that's where we want to put the hole */
	D2(printk(KERN_DEBUG "Adding new frag (%p) on right of node at (%p)\n", newfrag, this));
	rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
	} else {
	D2(printk(KERN_DEBUG "Adding new frag (%p) at root of tree\n", newfrag));
	rb_link_node(&newfrag->rb, NULL, &list->rb_node);
	}
	rb_insert_color(&newfrag->rb, list);
	return 0;
	}

	D2(printk(KERN_DEBUG "j_a_f_d_t_f: dealing with frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
	this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this));

	/* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
	* - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
	*/
	if (newfrag->ofs > this->ofs) {
	/* This node isn't completely obsoleted. The start of it remains valid */

	/* Mark the new node and the partially covered node REF_NORMAL -- let
	the GC take a look at them */
	mark_ref_normal(newfrag->node->raw);
	if (this->node)
	mark_ref_normal(this->node->raw);

	if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
	/* The new node splits 'this' frag into two */
	struct jffs2_node_frag *newfrag2 = jffs2_alloc_node_frag();
	if (!newfrag2) {
	jffs2_free_node_frag(newfrag);
	return -ENOMEM;
	}
	D2(printk(KERN_DEBUG "split old frag 0x%04x-0x%04x -->", this->ofs, this->ofs+this->size);
	if (this->node)
	printk("phys 0x%08x\n", ref_offset(this->node->raw));
	else
	printk("hole\n");
	)

	/* New second frag pointing to this's node */
	newfrag2->ofs = newfrag->ofs + newfrag->size;
	newfrag2->size = (this->ofs+this->size) - newfrag2->ofs;
	newfrag2->node = this->node;
	if (this->node)
	this->node->frags++;

	/* Adjust size of original 'this' */
	this->size = newfrag->ofs - this->ofs;

	/* Now, we know there's no node with offset
	greater than this->ofs but smaller than
	newfrag2->ofs or newfrag->ofs, for obvious
	reasons. So we can do a tree insert from
	'this' to insert newfrag, and a tree insert
	from newfrag to insert newfrag2. */
	jffs2_fragtree_insert(newfrag, this);
	rb_insert_color(&newfrag->rb, list);

	jffs2_fragtree_insert(newfrag2, newfrag);
	rb_insert_color(&newfrag2->rb, list);

	return 0;
	}
	/* New node just reduces 'this' frag in size, doesn't split it */
	this->size = newfrag->ofs - this->ofs;

	/* Again, we know it lives down here in the tree */
	jffs2_fragtree_insert(newfrag, this);
	rb_insert_color(&newfrag->rb, list);
	} else {
	/* New frag starts at the same point as 'this' used to. Replace
	it in the tree without doing a delete and insertion */
	D2(printk(KERN_DEBUG "Inserting newfrag (%p),%d-%d in before 'this' (%p),%d-%d\n",
	newfrag, newfrag->ofs, newfrag->ofs+newfrag->size,
	this, this->ofs, this->ofs+this->size));

	rb_replace_node(&this->rb, &newfrag->rb, list);

	if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
	D2(printk(KERN_DEBUG "Obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size));
	jffs2_obsolete_node_frag(c, this);
	} else {
	this->ofs += newfrag->size;
	this->size -= newfrag->size;

	jffs2_fragtree_insert(this, newfrag);
	rb_insert_color(&this->rb, list);
	return 0;
	}
	}
	/* OK, now we have newfrag added in the correct place in the tree, but
	frag_next(newfrag) may be a fragment which is overlapped by it
	*/
	while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
	/* 'this' frag is obsoleted completely. */
	D2(printk(KERN_DEBUG "Obsoleting node frag %p (%x-%x) and removing from tree\n", this, this->ofs, this->ofs+this->size));
	rb_erase(&this->rb, list);
	jffs2_obsolete_node_frag(c, this);
	}
	/* Now we're pointing at the first frag which isn't totally obsoleted by
	the new frag */

	if (!this \|\| newfrag->ofs + newfrag->size == this->ofs) {
	return 0;
	}
	/* Still some overlap but we don't need to move it in the tree */
	this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
	this->ofs = newfrag->ofs + newfrag->size;

	/* And mark them REF_NORMAL so the GC takes a look at them */
	if (this->node)
	mark_ref_normal(this->node->raw);
	mark_ref_normal(newfrag->node->raw);

	return 0;
	}

	void jffs2_truncate_fraglist (struct jffs2_sb_info c, struct rb_root list, uint32_t size)
	{
	struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);

	D1(printk(KERN_DEBUG "Truncating fraglist to 0x%08x bytes\n", size));

	/* We know frag->ofs <= size. That's what lookup does for us */
	if (frag && frag->ofs != size) {
	if (frag->ofs+frag->size >= size) {
	D1(printk(KERN_DEBUG "Truncating frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
	frag->size = size - frag->ofs;
	}
	frag = frag_next(frag);
	}
	while (frag && frag->ofs >= size) {
	struct jffs2_node_frag *next = frag_next(frag);

	D1(printk(KERN_DEBUG "Removing frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
	frag_erase(frag, list);
	jffs2_obsolete_node_frag(c, frag);
	frag = next;
	}
	}

	/* Scan the list of all nodes present for this ino, build map of versions, etc. */

	static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
	struct jffs2_inode_info *f,
	struct jffs2_raw_inode *latest_node);

	int jffs2_do_read_inode(struct jffs2_sb_info c, struct jffs2_inode_info f,
	uint32_t ino, struct jffs2_raw_inode *latest_node)
	{
	D2(printk(KERN_DEBUG "jffs2_do_read_inode(): getting inocache\n"));

	retry_inocache:
	spin_lock(&c->inocache_lock);
	f->inocache = jffs2_get_ino_cache(c, ino);

	D2(printk(KERN_DEBUG "jffs2_do_read_inode(): Got inocache at %p\n", f->inocache));

	if (f->inocache) {
	/* Check its state. We may need to wait before we can use it */
	switch(f->inocache->state) {
	case INO_STATE_UNCHECKED:
	case INO_STATE_CHECKEDABSENT:
	f->inocache->state = INO_STATE_READING;
	break;

	case INO_STATE_CHECKING:
	case INO_STATE_GC:
	/* If it's in either of these states, we need
	to wait for whoever's got it to finish and
	put it back. */
	D1(printk(KERN_DEBUG "jffs2_get_ino_cache_read waiting for ino #%u in state %d\n",
	ino, f->inocache->state));
	sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
	goto retry_inocache;

	case INO_STATE_READING:
	case INO_STATE_PRESENT:
	/* Eep. This should never happen. It can
	happen if Linux calls read_inode() again
	before clear_inode() has finished though. */
	printk(KERN_WARNING "Eep. Trying to read_inode #%u when it's already in state %d!\n", ino, f->inocache->state);
	/* Fail. That's probably better than allowing it to succeed */
	f->inocache = NULL;
	break;

	default:
	BUG();
	}
	}
	spin_unlock(&c->inocache_lock);

	if (!f->inocache && ino == 1) {
	/* Special case - no root inode on medium */
	f->inocache = jffs2_alloc_inode_cache();
	if (!f->inocache) {
	printk(KERN_CRIT "jffs2_do_read_inode(): Cannot allocate inocache for root inode\n");
	return -ENOMEM;
	}
	D1(printk(KERN_DEBUG "jffs2_do_read_inode(): Creating inocache for root inode\n"));
	memset(f->inocache, 0, sizeof(struct jffs2_inode_cache));
	f->inocache->ino = f->inocache->nlink = 1;
	f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache;
	f->inocache->state = INO_STATE_READING;
	jffs2_add_ino_cache(c, f->inocache);
	}
	if (!f->inocache) {
	printk(KERN_WARNING "jffs2_do_read_inode() on nonexistent ino %u\n", ino);
	return -ENOENT;
	}

	return jffs2_do_read_inode_internal(c, f, latest_node);
	}

	int jffs2_do_crccheck_inode(struct jffs2_sb_info c, struct jffs2_inode_cache ic)
	{
	struct jffs2_raw_inode n;
	struct jffs2_inode_info f = kmalloc(sizeof(f), GFP_KERNEL);
	int ret;

	if (!f)
	return -ENOMEM;

	memset(f, 0, sizeof(*f));
	init_MUTEX_LOCKED(&f->sem);
	f->inocache = ic;

	ret = jffs2_do_read_inode_internal(c, f, &n);
	if (!ret) {
	up(&f->sem);
	jffs2_do_clear_inode(c, f);
	}
	kfree (f);
	return ret;
	}

	static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
	struct jffs2_inode_info *f,
	struct jffs2_raw_inode *latest_node)
	{
	struct jffs2_tmp_dnode_info *tn = NULL;
	struct rb_root tn_list;
	struct rb_node rb, repl_rb;
	struct jffs2_full_dirent *fd_list;
	struct jffs2_full_dnode *fn = NULL;
	uint32_t crc;
	uint32_t latest_mctime, mctime_ver;
	uint32_t mdata_ver = 0;
	size_t retlen;
	int ret;

	D1(printk(KERN_DEBUG "jffs2_do_read_inode_internal(): ino #%u nlink is %d\n", f->inocache->ino, f->inocache->nlink));

	/* Grab all nodes relevant to this ino */
	ret = jffs2_get_inode_nodes(c, f, &tn_list, &fd_list, &f->highest_version, &latest_mctime, &mctime_ver);

	if (ret) {
	printk(KERN_CRIT "jffs2_get_inode_nodes() for ino %u returned %d\n", f->inocache->ino, ret);
	if (f->inocache->state == INO_STATE_READING)
	jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
	return ret;
	}
	f->dents = fd_list;

	rb = rb_first(&tn_list);

	while (rb) {
	tn = rb_entry(rb, struct jffs2_tmp_dnode_info, rb);
	fn = tn->fn;

	if (f->metadata) {
	if (likely(tn->version >= mdata_ver)) {
	D1(printk(KERN_DEBUG "Obsoleting old metadata at 0x%08x\n", ref_offset(f->metadata->raw)));
	jffs2_mark_node_obsolete(c, f->metadata->raw);
	jffs2_free_full_dnode(f->metadata);
	f->metadata = NULL;

	mdata_ver = 0;
	} else {
	/* This should never happen. */
	printk(KERN_WARNING "Er. New metadata at 0x%08x with ver %d is actually older than previous ver %d at 0x%08x\n",
	ref_offset(fn->raw), tn->version, mdata_ver, ref_offset(f->metadata->raw));
	jffs2_mark_node_obsolete(c, fn->raw);
	jffs2_free_full_dnode(fn);
	/* Fill in latest_node from the metadata, not this one we're about to free... */
	fn = f->metadata;
	goto next_tn;
	}
	}

	if (fn->size) {
	jffs2_add_full_dnode_to_inode(c, f, fn);
	} else {
	/* Zero-sized node at end of version list. Just a metadata update */
	D1(printk(KERN_DEBUG "metadata @%08x: ver %d\n", ref_offset(fn->raw), tn->version));
	f->metadata = fn;
	mdata_ver = tn->version;
	}
	next_tn:
	BUG_ON(rb->rb_left);
	if (rb->rb_parent && rb->rb_parent->rb_left == rb) {
	/* We were then left-hand child of our parent. We need
	to move our own right-hand child into our place. */
	repl_rb = rb->rb_right;
	if (repl_rb)
	repl_rb->rb_parent = rb->rb_parent;
	} else
	repl_rb = NULL;

	rb = rb_next(rb);

	/* Remove the spent tn from the tree; don't bother rebalancing
	but put our right-hand child in our own place. */
	if (tn->rb.rb_parent) {
	if (tn->rb.rb_parent->rb_left == &tn->rb)
	tn->rb.rb_parent->rb_left = repl_rb;
	else if (tn->rb.rb_parent->rb_right == &tn->rb)
	tn->rb.rb_parent->rb_right = repl_rb;
	else BUG();
	} else if (tn->rb.rb_right)
	tn->rb.rb_right->rb_parent = NULL;

	jffs2_free_tmp_dnode_info(tn);
	}
	jffs2_dbg_fragtree_paranoia_check(f);

	if (!fn) {
	/* No data nodes for this inode. */
	if (f->inocache->ino != 1) {
	printk(KERN_WARNING "jffs2_do_read_inode(): No data nodes found for ino #%u\n", f->inocache->ino);
	if (!fd_list) {
	if (f->inocache->state == INO_STATE_READING)
	jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
	return -EIO;
	}
	printk(KERN_WARNING "jffs2_do_read_inode(): But it has children so we fake some modes for it\n");
	}
	latest_node->mode = cpu_to_jemode(S_IFDIR\|S_IRUGO\|S_IWUSR\|S_IXUGO);
	latest_node->version = cpu_to_je32(0);
	latest_node->atime = latest_node->ctime = latest_node->mtime = cpu_to_je32(0);
	latest_node->isize = cpu_to_je32(0);
	latest_node->gid = cpu_to_je16(0);
	latest_node->uid = cpu_to_je16(0);
	if (f->inocache->state == INO_STATE_READING)
	jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);
	return 0;
	}

	ret = jffs2_flash_read(c, ref_offset(fn->raw), sizeof(latest_node), &retlen, (void )latest_node);
	if (ret \|\| retlen != sizeof(*latest_node)) {
	printk(KERN_NOTICE "MTD read in jffs2_do_read_inode() failed: Returned %d, %zd of %zd bytes read\n",
	ret, retlen, sizeof(*latest_node));
	/* FIXME: If this fails, there seems to be a memory leak. Find it. */
	up(&f->sem);
	jffs2_do_clear_inode(c, f);
	return ret?ret:-EIO;
	}

	crc = crc32(0, latest_node, sizeof(*latest_node)-8);
	if (crc != je32_to_cpu(latest_node->node_crc)) {
	printk(KERN_NOTICE "CRC failed for read_inode of inode %u at physical location 0x%x\n", f->inocache->ino, ref_offset(fn->raw));
	up(&f->sem);
	jffs2_do_clear_inode(c, f);
	return -EIO;
	}

	switch(jemode_to_cpu(latest_node->mode) & S_IFMT) {
	case S_IFDIR:
	if (mctime_ver > je32_to_cpu(latest_node->version)) {
	/* The times in the latest_node are actually older than
	mctime in the latest dirent. Cheat. */
	latest_node->ctime = latest_node->mtime = cpu_to_je32(latest_mctime);
	}
	break;


	case S_IFREG:
	/* If it was a regular file, truncate it to the latest node's isize */
	jffs2_truncate_fraglist(c, &f->fragtree, je32_to_cpu(latest_node->isize));
	break;

	case S_IFLNK:
	/* Hack to work around broken isize in old symlink code.
	Remove this when dwmw2 comes to his senses and stops
	symlinks from being an entirely gratuitous special
	case. */
	if (!je32_to_cpu(latest_node->isize))
	latest_node->isize = latest_node->dsize;

	if (f->inocache->state != INO_STATE_CHECKING) {
	/* Symlink's inode data is the target path. Read it and
	* keep in RAM to facilitate quick follow symlink operation.
	* We use f->dents field to store the target path, which
	* is somewhat ugly. */
	f->dents = kmalloc(je32_to_cpu(latest_node->csize) + 1, GFP_KERNEL);
	if (!f->dents) {
	printk(KERN_WARNING "Can't allocate %d bytes of memory "
	"for the symlink target path cache\n",
	je32_to_cpu(latest_node->csize));
	up(&f->sem);
	jffs2_do_clear_inode(c, f);
	return -ENOMEM;
	}

	ret = jffs2_flash_read(c, ref_offset(fn->raw) + sizeof(*latest_node),
	je32_to_cpu(latest_node->csize), &retlen, (char *)f->dents);

	if (ret \|\| retlen != je32_to_cpu(latest_node->csize)) {
	if (retlen != je32_to_cpu(latest_node->csize))
	ret = -EIO;
	kfree(f->dents);
	f->dents = NULL;
	up(&f->sem);
	jffs2_do_clear_inode(c, f);
	return -ret;
	}

	((char *)f->dents)[je32_to_cpu(latest_node->csize)] = '\0';
	D1(printk(KERN_DEBUG "jffs2_do_read_inode(): symlink's target '%s' cached\n",
	(char *)f->dents));
	}

	/* fall through... */

	case S_IFBLK:
	case S_IFCHR:
	/* Certain inode types should have only one data node, and it's
	kept as the metadata node */
	if (f->metadata) {
	printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o had metadata node\n",
	f->inocache->ino, jemode_to_cpu(latest_node->mode));
	up(&f->sem);
	jffs2_do_clear_inode(c, f);
	return -EIO;
	}
	if (!frag_first(&f->fragtree)) {
	printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o has no fragments\n",
	f->inocache->ino, jemode_to_cpu(latest_node->mode));
	up(&f->sem);
	jffs2_do_clear_inode(c, f);
	return -EIO;
	}
	/* ASSERT: f->fraglist != NULL */
	if (frag_next(frag_first(&f->fragtree))) {
	printk(KERN_WARNING "Argh. Special inode #%u with mode 0x%x had more than one node\n",
	f->inocache->ino, jemode_to_cpu(latest_node->mode));
	/* FIXME: Deal with it - check crc32, check for duplicate node, check times and discard the older one */
	up(&f->sem);
	jffs2_do_clear_inode(c, f);
	return -EIO;
	}
	/* OK. We're happy */
	f->metadata = frag_first(&f->fragtree)->node;
	jffs2_free_node_frag(frag_first(&f->fragtree));
	f->fragtree = RB_ROOT;
	break;
	}
	if (f->inocache->state == INO_STATE_READING)
	jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);

	return 0;
	}

	void jffs2_do_clear_inode(struct jffs2_sb_info c, struct jffs2_inode_info f)
	{
	struct jffs2_full_dirent fd, fds;
	int deleted;

	down(&f->sem);
	deleted = f->inocache && !f->inocache->nlink;

	if (f->inocache && f->inocache->state != INO_STATE_CHECKING)
	jffs2_set_inocache_state(c, f->inocache, INO_STATE_CLEARING);

	if (f->metadata) {
	if (deleted)
	jffs2_mark_node_obsolete(c, f->metadata->raw);
	jffs2_free_full_dnode(f->metadata);
	}

	jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL);

	/* For symlink inodes we us f->dents to store the target path name */
	if (S_ISLNK(OFNI_EDONI_2SFFJ(f)->i_mode)) {
	if (f->dents) {
	kfree(f->dents);
	f->dents = NULL;
	}
	} else {
	fds = f->dents;

	while(fds) {
	fd = fds;
	fds = fd->next;
	jffs2_free_full_dirent(fd);
	}
	}

	if (f->inocache && f->inocache->state != INO_STATE_CHECKING) {
	jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
	if (f->inocache->nodes == (void *)f->inocache)
	jffs2_del_ino_cache(c, f->inocache);
	}

	up(&f->sem);
	}