[JFFS2] Split a large routine on several smaller.

Signed-off-by: Artem B. Bityutskiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 336 insertions, 261 deletions

diff --git a/fs/jffs2/nodelist.c b/fs/jffs2/nodelist.c
index 4991c348f6ec..a04111530f4d 100644
--- a/fs/jffs2/nodelist.c
+++ b/fs/jffs2/nodelist.c
@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: nodelist.c,v 1.98 2005/07/10 15:15:32 dedekind Exp $
+ * $Id: nodelist.c,v 1.99 2005/07/15 10:13:54 dedekind Exp $
  *
  */
 
@@ -137,6 +137,307 @@ static struct jffs2_raw_node_ref *jffs2_first_valid_node(struct jffs2_raw_node_r
 	return NULL;
 }
 
+/*
+ * Helper function for jffs2_get_inode_nodes().
+ * It is called every time an directory entry node is found.
+ *
+ * Returns: 0 on succes;
+ * 	    1 if the node should be marked obsolete;
+ * 	    negative error code on failure.
+ */
+static inline int
+read_direntry(struct jffs2_sb_info *c,
+	      struct jffs2_raw_node_ref *ref,
+	      struct jffs2_raw_dirent *rd,
+	      uint32_t read,
+	      struct jffs2_full_dirent **fdp,
+	      int32_t *latest_mctime,
+	      uint32_t *mctime_ver)
+{
+	struct jffs2_full_dirent *fd;
+	
+	/* The direntry nodes are checked during the flash scanning */
+	BUG_ON(ref_flags(ref) == REF_UNCHECKED);
+	/* Obsoleted. This cannot happen, surely? dwmw2 20020308 */
+	BUG_ON(ref_obsolete(ref));
+			
+	/* Sanity check */
+	if (unlikely(PAD((rd->nsize + sizeof(*rd))) != PAD(je32_to_cpu(rd->totlen)))) {
+		printk(KERN_ERR "Error! Illegal nsize in node at %#08x: nsize %#02x, totlen %#04x\n",
+		       ref_offset(ref), rd->nsize, je32_to_cpu(rd->totlen));
+		return 1;
+	}
+	
+	fd = jffs2_alloc_full_dirent(rd->nsize + 1);
+	if (unlikely(!fd))
+		return -ENOMEM;
+
+	fd->raw = ref;
+	fd->version = je32_to_cpu(rd->version);
+	fd->ino = je32_to_cpu(rd->ino);
+	fd->type = rd->type;
+
+	/* Pick out the mctime of the latest dirent */
+	if(fd->version > *mctime_ver) {
+		*mctime_ver = fd->version;
+		*latest_mctime = je32_to_cpu(rd->mctime);
+	}
+
+	/* 
+	 * Copy as much of the name as possible from the raw
+	 * dirent we've already read from the flash.
+	 */
+	if (read > sizeof(*rd))
+		memcpy(&fd->name[0], &rd->name[0],
+		       min_t(uint32_t, rd->nsize, (read - sizeof(*rd)) ));
+		
+	/* Do we need to copy any more of the name directly from the flash? */
+	if (rd->nsize + sizeof(*rd) > read) {
+		/* FIXME: point() */
+		int err;
+		int already = read - sizeof(*rd);
+			
+		err = jffs2_flash_read(c, (ref_offset(ref)) + read, 
+				rd->nsize - already, &read, &fd->name[already]);
+		if (unlikely(read != rd->nsize - already) && likely(!err))
+			return -EIO;
+			
+		if (unlikely(err)) {
+			printk(KERN_WARNING "Read remainder of name in jffs2_get_inode_nodes(): error %d\n", err);
+			jffs2_free_full_dirent(fd);
+			return -EIO;
+		}
+	}
+	
+	fd->nhash = full_name_hash(fd->name, rd->nsize);
+	fd->next = NULL;
+	fd->name[rd->nsize] = '\0';
+	
+	/*
+	 * Wheee. We now have a complete jffs2_full_dirent structure, with
+	 * the name in it and everything. Link it into the list 
+	 */
+	D1(printk(KERN_DEBUG "Adding fd \"%s\", ino #%u\n", fd->name, fd->ino));
+
+	jffs2_add_fd_to_list(c, fd, fdp);
+
+	return 0;
+}
+
+/*
+ * Helper function for jffs2_get_inode_nodes().
+ * It is called every time an inode node is found.
+ *
+ * Returns: 0 on succes;
+ * 	    1 if the node should be marked obsolete;
+ * 	    negative error code on failure.
+ */
+static inline int
+read_dnode(struct jffs2_sb_info *c,
+	   struct jffs2_raw_node_ref *ref,
+	   struct jffs2_raw_inode *rd,
+	   uint32_t read,
+	   struct rb_root *tnp,
+	   int32_t *latest_mctime,
+	   uint32_t *mctime_ver)
+{
+	struct jffs2_eraseblock *jeb;
+	struct jffs2_tmp_dnode_info *tn;
+	
+	/* Obsoleted. This cannot happen, surely? dwmw2 20020308 */
+	BUG_ON(ref_obsolete(ref));
+
+	/* If we've never checked the CRCs on this node, check them now */
+	if (ref_flags(ref) == REF_UNCHECKED) {
+		uint32_t crc, len;
+
+		crc = crc32(0, rd, sizeof(*rd) - 8);
+		if (unlikely(crc != je32_to_cpu(rd->node_crc))) {
+			printk(KERN_WARNING "Header CRC failed on node at %#08x: read %#08x, calculated %#08x\n",
+					ref_offset(ref), je32_to_cpu(rd->node_crc), crc);
+			return 1;
+		}
+		
+		/* Sanity checks */
+		if (unlikely(je32_to_cpu(rd->offset) > je32_to_cpu(rd->isize)) ||
+		    unlikely(PAD(je32_to_cpu(rd->csize) + sizeof(*rd)) != PAD(je32_to_cpu(rd->totlen)))) {
+			printk(KERN_WARNING "Inode corrupted at %#08x, totlen %d, #ino  %d, version %d, "
+				"isize %d, csize %d, dsize %d \n",
+				ref_offset(ref),  je32_to_cpu(rd->totlen),  je32_to_cpu(rd->ino),
+				je32_to_cpu(rd->version),  je32_to_cpu(rd->isize), 
+				je32_to_cpu(rd->csize), je32_to_cpu(rd->dsize));
+			return 1;
+		}
+
+		if (rd->compr != JFFS2_COMPR_ZERO && je32_to_cpu(rd->csize)) {
+			unsigned char *buf = NULL;
+			uint32_t pointed = 0;
+			int err;
+#ifndef __ECOS
+			if (c->mtd->point) {
+				err = c->mtd->point (c->mtd, ref_offset(ref) + sizeof(*rd), je32_to_cpu(rd->csize),
+						     &read, &buf);
+				if (unlikely(read < je32_to_cpu(rd->csize)) && likely(!err)) {
+					D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", read));
+					c->mtd->unpoint(c->mtd, buf, ref_offset(ref) + sizeof(*rd),
+							je32_to_cpu(rd->csize));
+				} else if (unlikely(err)){
+					D1(printk(KERN_DEBUG "MTD point failed %d\n", err));
+				} else
+					pointed = 1; /* succefully pointed to device */
+			}
+#endif					
+			if(!pointed){
+				buf = kmalloc(je32_to_cpu(rd->csize), GFP_KERNEL);
+				if (!buf)
+					return -ENOMEM;
+				
+				err = jffs2_flash_read(c, ref_offset(ref) + sizeof(*rd), je32_to_cpu(rd->csize),
+							&read, buf);
+				if (unlikely(read != je32_to_cpu(rd->csize)) && likely(!err))
+					err = -EIO;
+				if (err) {
+					kfree(buf);
+					return err;
+				}
+			}
+			crc = crc32(0, buf, je32_to_cpu(rd->csize));
+			if(!pointed)
+				kfree(buf);
+#ifndef __ECOS
+			else
+				c->mtd->unpoint(c->mtd, buf, ref_offset(ref) + sizeof(*rd), je32_to_cpu(rd->csize));
+#endif
+
+			if (crc != je32_to_cpu(rd->data_crc)) {
+				printk(KERN_NOTICE "Data CRC failed on node at %#08x: read %#08x, calculated %#08x\n",
+				       ref_offset(ref), je32_to_cpu(rd->data_crc), crc);
+				return 1;
+			}
+			
+		}
+
+		/* Mark the node as having been checked and fix the accounting accordingly */
+		jeb = &c->blocks[ref->flash_offset / c->sector_size];
+		len = ref_totlen(c, jeb, ref);
+
+		spin_lock(&c->erase_completion_lock);
+		jeb->used_size += len;
+		jeb->unchecked_size -= len;
+		c->used_size += len;
+		c->unchecked_size -= len;
+
+		/* If node covers at least a whole page, or if it starts at the 
+		   beginning of a page and runs to the end of the file, or if 
+		   it's a hole node, mark it REF_PRISTINE, else REF_NORMAL. 
+
+		   If it's actually overlapped, it'll get made NORMAL (or OBSOLETE) 
+		   when the overlapping node(s) get added to the tree anyway. 
+		*/
+		if ((je32_to_cpu(rd->dsize) >= PAGE_CACHE_SIZE) ||
+		    ( ((je32_to_cpu(rd->offset) & (PAGE_CACHE_SIZE-1))==0) &&
+		      (je32_to_cpu(rd->dsize) + je32_to_cpu(rd->offset) == je32_to_cpu(rd->isize)))) {
+			D1(printk(KERN_DEBUG "Marking node at %#08x REF_PRISTINE\n", ref_offset(ref)));
+			ref->flash_offset = ref_offset(ref) | REF_PRISTINE;
+		} else {
+			D1(printk(KERN_DEBUG "Marking node at %#08x REF_NORMAL\n", ref_offset(ref)));
+			ref->flash_offset = ref_offset(ref) | REF_NORMAL;
+		}
+		spin_unlock(&c->erase_completion_lock);
+	}
+
+	tn = jffs2_alloc_tmp_dnode_info();
+	if (!tn) {
+		D1(printk(KERN_DEBUG "alloc tn failed\n"));
+		return -ENOMEM;
+	}
+
+	tn->fn = jffs2_alloc_full_dnode();
+	if (!tn->fn) {
+		D1(printk(KERN_DEBUG "alloc fn failed\n"));
+		jffs2_free_tmp_dnode_info(tn);
+		return -ENOMEM;
+	}
+	
+	tn->version = je32_to_cpu(rd->version);
+	tn->fn->ofs = je32_to_cpu(rd->offset);
+	tn->fn->raw = ref;
+	
+	/* There was a bug where we wrote hole nodes out with
+	   csize/dsize swapped. Deal with it */
+	if (rd->compr == JFFS2_COMPR_ZERO && !je32_to_cpu(rd->dsize) && je32_to_cpu(rd->csize))
+		tn->fn->size = je32_to_cpu(rd->csize);
+	else // normal case...
+		tn->fn->size = je32_to_cpu(rd->dsize);
+
+	D1(printk(KERN_DEBUG "dnode @%08x: ver %u, offset %#04x, dsize %#04x\n",
+		  ref_offset(ref), je32_to_cpu(rd->version),
+		  je32_to_cpu(rd->offset), je32_to_cpu(rd->dsize)));
+	
+	jffs2_add_tn_to_tree(tn, tnp);
+
+	return 0;
+}
+
+/*
+ * Helper function for jffs2_get_inode_nodes().
+ * It is called every time an unknown node is found.
+ *
+ * Returns: 0 on succes;
+ * 	    1 if the node should be marked obsolete;
+ * 	    negative error code on failure.
+ */
+static inline int
+read_unknown(struct jffs2_sb_info *c,
+	     struct jffs2_raw_node_ref *ref,
+	     struct jffs2_unknown_node *un,
+	     uint32_t read)
+{
+	/* We don't mark unknown nodes as REF_UNCHECKED */
+	BUG_ON(ref_flags(ref) == REF_UNCHECKED);
+	
+	un->nodetype = cpu_to_je16(JFFS2_NODE_ACCURATE | je16_to_cpu(un->nodetype));
+
+	if (crc32(0, un, sizeof(struct jffs2_unknown_node) - 4) != je32_to_cpu(un->hdr_crc)) {
+
+		/* Hmmm. This should have been caught at scan time. */
+		printk(KERN_WARNING "Warning! Node header CRC failed at %#08x. "
+				"But it must have been OK earlier.\n", ref_offset(ref));
+		D1(printk(KERN_DEBUG "Node was: { %#04x, %#04x, %#08x, %#08x }\n", 
+			je16_to_cpu(un->magic), je16_to_cpu(un->nodetype),
+			je32_to_cpu(un->totlen), je32_to_cpu(un->hdr_crc)));
+		return 1;
+	} else {
+		switch(je16_to_cpu(un->nodetype) & JFFS2_COMPAT_MASK) {
+
+		case JFFS2_FEATURE_INCOMPAT:
+			printk(KERN_NOTICE "Unknown INCOMPAT nodetype %#04X at %#08x\n",
+					je16_to_cpu(un->nodetype), ref_offset(ref));
+			/* EEP */
+			BUG();
+			break;
+
+		case JFFS2_FEATURE_ROCOMPAT:
+			printk(KERN_NOTICE "Unknown ROCOMPAT nodetype %#04X at %#08x\n",
+					je16_to_cpu(un->nodetype), ref_offset(ref));
+			BUG_ON(!(c->flags & JFFS2_SB_FLAG_RO));
+			break;
+
+		case JFFS2_FEATURE_RWCOMPAT_COPY:
+			printk(KERN_NOTICE "Unknown RWCOMPAT_COPY nodetype %#04X at %#08x\n",
+					je16_to_cpu(un->nodetype), ref_offset(ref));
+			break;
+
+		case JFFS2_FEATURE_RWCOMPAT_DELETE:
+			printk(KERN_NOTICE "Unknown RWCOMPAT_DELETE nodetype %#04X at %#08x\n",
+					je16_to_cpu(un->nodetype), ref_offset(ref));
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 /* Get tmp_dnode_info and full_dirent for all non-obsolete nodes associated
    with this ino, returning the former in order of version */
 
@@ -146,9 +447,8 @@ int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 			  uint32_t *mctime_ver)
 {
 	struct jffs2_raw_node_ref *ref, *valid_ref;
-	struct jffs2_tmp_dnode_info *tn;
 	struct rb_root ret_tn = RB_ROOT;
-	struct jffs2_full_dirent *fd, *ret_fd = NULL;
+	struct jffs2_full_dirent *ret_fd = NULL;
 	union jffs2_node_union node;
 	size_t retlen;
 	int err;
@@ -186,292 +486,67 @@ int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 			goto free_out;
 		}
 			
-
-			/* Check we've managed to read at least the common node header */
-		if (retlen < min_t(uint32_t, ref_totlen(c, NULL, ref), sizeof(node.u))) {
-			printk(KERN_WARNING "short read in get_inode_nodes()\n");
-			err = -EIO;
-			goto free_out;
-		}
-			
 		switch (je16_to_cpu(node.u.nodetype)) {
+			
 		case JFFS2_NODETYPE_DIRENT:
 			D1(printk(KERN_DEBUG "Node at %08x (%d) is a dirent node\n", ref_offset(ref), ref_flags(ref)));
-			if (ref_flags(ref) == REF_UNCHECKED) {
-				printk(KERN_WARNING "BUG: Dirent node at 0x%08x never got checked? How?\n", ref_offset(ref));
-				BUG();
-			}
+			
 			if (retlen < sizeof(node.d)) {
-				printk(KERN_WARNING "short read in get_inode_nodes()\n");
+				printk(KERN_WARNING "Warning! Short read dirent at %#08x\n", ref_offset(ref));
 				err = -EIO;
 				goto free_out;
 			}
-			/* sanity check */
-			if (PAD((node.d.nsize + sizeof (node.d))) != PAD(je32_to_cpu (node.d.totlen))) {
-				printk(KERN_NOTICE "jffs2_get_inode_nodes(): Illegal nsize in node at 0x%08x: nsize 0x%02x, totlen %04x\n",
-				       ref_offset(ref), node.d.nsize, je32_to_cpu(node.d.totlen));
+
+			err = read_direntry(c, ref, &node.d, retlen, &ret_fd, latest_mctime, mctime_ver);
+			if (err == 1) {
 				jffs2_mark_node_obsolete(c, ref);
-				spin_lock(&c->erase_completion_lock);
-				continue;
-			}
+				break;
+			} else if (unlikely(err))
+				goto free_out;
+			
 			if (je32_to_cpu(node.d.version) > *highest_version)
 				*highest_version = je32_to_cpu(node.d.version);
-			if (ref_obsolete(ref)) {
-				/* Obsoleted. This cannot happen, surely? dwmw2 20020308 */
-				printk(KERN_ERR "Dirent node at 0x%08x became obsolete while we weren't looking\n",
-				       ref_offset(ref));
-				BUG();
-			}
-			
-			fd = jffs2_alloc_full_dirent(node.d.nsize+1);
-			if (!fd) {
-				err = -ENOMEM;
-				goto free_out;
-			}
-			fd->raw = ref;
-			fd->version = je32_to_cpu(node.d.version);
-			fd->ino = je32_to_cpu(node.d.ino);
-			fd->type = node.d.type;
-
-			/* Pick out the mctime of the latest dirent */
-			if(fd->version > *mctime_ver) {
-				*mctime_ver = fd->version;
-				*latest_mctime = je32_to_cpu(node.d.mctime);
-			}
 
-			/* memcpy as much of the name as possible from the raw
-			   dirent we've already read from the flash
-			*/
-			if (retlen > sizeof(struct jffs2_raw_dirent))
-				memcpy(&fd->name[0], &node.d.name[0], min_t(uint32_t, node.d.nsize, (retlen-sizeof(struct jffs2_raw_dirent))));
-				
-			/* Do we need to copy any more of the name directly
-			   from the flash?
-			*/
-			if (node.d.nsize + sizeof(struct jffs2_raw_dirent) > retlen) {
-				/* FIXME: point() */
-				int already = retlen - sizeof(struct jffs2_raw_dirent);
-					
-				err = jffs2_flash_read(c, (ref_offset(ref)) + retlen, 
-						   node.d.nsize - already, &retlen, &fd->name[already]);
-				if (!err && retlen != node.d.nsize - already)
-					err = -EIO;
-					
-				if (err) {
-					printk(KERN_WARNING "Read remainder of name in jffs2_get_inode_nodes(): error %d\n", err);
-					jffs2_free_full_dirent(fd);
-					goto free_out;
-				}
-			}
-			fd->nhash = full_name_hash(fd->name, node.d.nsize);
-			fd->next = NULL;
-			fd->name[node.d.nsize] = '\0';
-				/* Wheee. We now have a complete jffs2_full_dirent structure, with
-				   the name in it and everything. Link it into the list 
-				*/
-			D1(printk(KERN_DEBUG "Adding fd \"%s\", ino #%u\n", fd->name, fd->ino));
-			jffs2_add_fd_to_list(c, fd, &ret_fd);
 			break;
 
 		case JFFS2_NODETYPE_INODE:
 			D1(printk(KERN_DEBUG "Node at %08x (%d) is a data node\n", ref_offset(ref), ref_flags(ref)));
+			
 			if (retlen < sizeof(node.i)) {
-				printk(KERN_WARNING "read too short for dnode\n");
+				printk(KERN_WARNING "Warning! Short read dnode at %#08x\n", ref_offset(ref));
 				err = -EIO;
 				goto free_out;
 			}
-			if (je32_to_cpu(node.i.version) > *highest_version)
-				*highest_version = je32_to_cpu(node.i.version);
-			D1(printk(KERN_DEBUG "version %d, highest_version now %d\n", je32_to_cpu(node.i.version), *highest_version));
-
-			if (ref_obsolete(ref)) {
-				/* Obsoleted. This cannot happen, surely? dwmw2 20020308 */
-				printk(KERN_ERR "Inode node at 0x%08x became obsolete while we weren't looking\n",
-				       ref_offset(ref));
-				BUG();
-			}
-
-			/* If we've never checked the CRCs on this node, check them now. */
-			if (ref_flags(ref) == REF_UNCHECKED) {
-				uint32_t crc, len;
-				struct jffs2_eraseblock *jeb;
-
-				crc = crc32(0, &node, sizeof(node.i)-8);
-				if (crc != je32_to_cpu(node.i.node_crc)) {
-					printk(KERN_NOTICE "jffs2_get_inode_nodes(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
-					       ref_offset(ref), je32_to_cpu(node.i.node_crc), crc);
-					jffs2_mark_node_obsolete(c, ref);
-					spin_lock(&c->erase_completion_lock);
-					continue;
-				}
-				
-				/* sanity checks */
-				if ( je32_to_cpu(node.i.offset) > je32_to_cpu(node.i.isize) ||
-				     PAD(je32_to_cpu(node.i.csize) + sizeof (node.i)) != PAD(je32_to_cpu(node.i.totlen))) {
-					printk(KERN_NOTICE "jffs2_get_inode_nodes(): Inode corrupted at 0x%08x, totlen %d, #ino  %d, version %d, isize %d, csize %d, dsize %d \n",
-						ref_offset(ref),  je32_to_cpu(node.i.totlen),  je32_to_cpu(node.i.ino),
-						je32_to_cpu(node.i.version),  je32_to_cpu(node.i.isize), 
-						je32_to_cpu(node.i.csize), je32_to_cpu(node.i.dsize));
-					jffs2_mark_node_obsolete(c, ref);
-					spin_lock(&c->erase_completion_lock);
-					continue;
-				}
 
-				if (node.i.compr != JFFS2_COMPR_ZERO && je32_to_cpu(node.i.csize)) {
-					unsigned char *buf=NULL;
-					uint32_t pointed = 0;
-#ifndef __ECOS
-					if (c->mtd->point) {
-						err = c->mtd->point (c->mtd, ref_offset(ref) + sizeof(node.i), je32_to_cpu(node.i.csize),
-								     &retlen, &buf);
-						if (!err && retlen < je32_to_cpu(node.i.csize)) {
-							D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", retlen));
-							c->mtd->unpoint(c->mtd, buf, ref_offset(ref) + sizeof(node.i), je32_to_cpu(node.i.csize));
-						} else if (err){
-							D1(printk(KERN_DEBUG "MTD point failed %d\n", err));
-						} else
-							pointed = 1; /* succefully pointed to device */
-					}
-#endif					
-					if(!pointed){
-						buf = kmalloc(je32_to_cpu(node.i.csize), GFP_KERNEL);
-						if (!buf)
-							return -ENOMEM;
-						
-						err = jffs2_flash_read(c, ref_offset(ref) + sizeof(node.i), je32_to_cpu(node.i.csize),
-								       &retlen, buf);
-						if (!err && retlen != je32_to_cpu(node.i.csize))
-							err = -EIO;
-						if (err) {
-							kfree(buf);
-							return err;
-						}
-					}
-					crc = crc32(0, buf, je32_to_cpu(node.i.csize));
-					if(!pointed)
-						kfree(buf);
-#ifndef __ECOS
-					else
-						c->mtd->unpoint(c->mtd, buf, ref_offset(ref) + sizeof(node.i), je32_to_cpu(node.i.csize));
-#endif
-
-					if (crc != je32_to_cpu(node.i.data_crc)) {
-						printk(KERN_NOTICE "jffs2_get_inode_nodes(): Data CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
-						       ref_offset(ref), je32_to_cpu(node.i.data_crc), crc);
-						jffs2_mark_node_obsolete(c, ref);
-						spin_lock(&c->erase_completion_lock);
-						continue;
-					}
-					
-				}
-
-				/* Mark the node as having been checked and fix the accounting accordingly */
-				spin_lock(&c->erase_completion_lock);
-				jeb = &c->blocks[ref->flash_offset / c->sector_size];
-				len = ref_totlen(c, jeb, ref);
-
-				jeb->used_size += len;
-				jeb->unchecked_size -= len;
-				c->used_size += len;
-				c->unchecked_size -= len;
-
-				/* If node covers at least a whole page, or if it starts at the 
-				   beginning of a page and runs to the end of the file, or if 
-				   it's a hole node, mark it REF_PRISTINE, else REF_NORMAL. 
-
-				   If it's actually overlapped, it'll get made NORMAL (or OBSOLETE) 
-				   when the overlapping node(s) get added to the tree anyway. 
-				*/
-				if ((je32_to_cpu(node.i.dsize) >= PAGE_CACHE_SIZE) ||
-				    ( ((je32_to_cpu(node.i.offset)&(PAGE_CACHE_SIZE-1))==0) &&
-				      (je32_to_cpu(node.i.dsize)+je32_to_cpu(node.i.offset) ==  je32_to_cpu(node.i.isize)))) {
-					D1(printk(KERN_DEBUG "Marking node at 0x%08x REF_PRISTINE\n", ref_offset(ref)));
-					ref->flash_offset = ref_offset(ref) | REF_PRISTINE;
-				} else {
-					D1(printk(KERN_DEBUG "Marking node at 0x%08x REF_NORMAL\n", ref_offset(ref)));
-					ref->flash_offset = ref_offset(ref) | REF_NORMAL;
-				}
-				spin_unlock(&c->erase_completion_lock);
-			}
-
-			tn = jffs2_alloc_tmp_dnode_info();
-			if (!tn) {
-				D1(printk(KERN_DEBUG "alloc tn failed\n"));
-				err = -ENOMEM;
+			err = read_dnode(c, ref, &node.i, retlen, &ret_tn, latest_mctime, mctime_ver);
+			if (err == 1) {
+				jffs2_mark_node_obsolete(c, ref);
+				break;
+			} else if (unlikely(err))
 				goto free_out;
-			}
 
-			tn->fn = jffs2_alloc_full_dnode();
-			if (!tn->fn) {
-				D1(printk(KERN_DEBUG "alloc fn failed\n"));
-				err = -ENOMEM;
-				jffs2_free_tmp_dnode_info(tn);
-				goto free_out;
-			}
-			tn->version = je32_to_cpu(node.i.version);
-			tn->fn->ofs = je32_to_cpu(node.i.offset);
-			/* There was a bug where we wrote hole nodes out with
-			   csize/dsize swapped. Deal with it */
-			if (node.i.compr == JFFS2_COMPR_ZERO && !je32_to_cpu(node.i.dsize) && je32_to_cpu(node.i.csize))
-				tn->fn->size = je32_to_cpu(node.i.csize);
-			else // normal case...
-				tn->fn->size = je32_to_cpu(node.i.dsize);
-			tn->fn->raw = ref;
-			D1(printk(KERN_DEBUG "dnode @%08x: ver %u, offset %04x, dsize %04x\n",
-				  ref_offset(ref), je32_to_cpu(node.i.version),
-				  je32_to_cpu(node.i.offset), je32_to_cpu(node.i.dsize)));
-			jffs2_add_tn_to_tree(tn, &ret_tn);
+			if (je32_to_cpu(node.i.version) > *highest_version)
+				*highest_version = je32_to_cpu(node.i.version);
+			
+			D1(printk(KERN_DEBUG "version %d, highest_version now %d\n",
+					je32_to_cpu(node.i.version), *highest_version));
+
 			break;
 
 		default:
-			if (ref_flags(ref) == REF_UNCHECKED) {
-				struct jffs2_eraseblock *jeb;
-				uint32_t len;
-
-				printk(KERN_ERR "Eep. Unknown node type %04x at %08x was marked REF_UNCHECKED\n",
-				       je16_to_cpu(node.u.nodetype), ref_offset(ref));
-
-				/* Mark the node as having been checked and fix the accounting accordingly */
-				spin_lock(&c->erase_completion_lock);
-				jeb = &c->blocks[ref->flash_offset / c->sector_size];
-				len = ref_totlen(c, jeb, ref);
-
-				jeb->used_size += len;
-				jeb->unchecked_size -= len;
-				c->used_size += len;
-				c->unchecked_size -= len;
-
-				mark_ref_normal(ref);
-				spin_unlock(&c->erase_completion_lock);
+			/* Check we've managed to read at least the common node header */
+			if (retlen < sizeof(struct jffs2_unknown_node)) {
+				printk(KERN_WARNING "Warning! Short read unknown node at %#08x\n",
+						ref_offset(ref));
+				return -EIO;
 			}
-			node.u.nodetype = cpu_to_je16(JFFS2_NODE_ACCURATE | je16_to_cpu(node.u.nodetype));
-			if (crc32(0, &node, sizeof(struct jffs2_unknown_node)-4) != je32_to_cpu(node.u.hdr_crc)) {
-				/* Hmmm. This should have been caught at scan time. */
-				printk(KERN_ERR "Node header CRC failed at %08x. But it must have been OK earlier.\n",
-				       ref_offset(ref));
-				printk(KERN_ERR "Node was: { %04x, %04x, %08x, %08x }\n", 
-				       je16_to_cpu(node.u.magic), je16_to_cpu(node.u.nodetype), je32_to_cpu(node.u.totlen),
-				       je32_to_cpu(node.u.hdr_crc));
-				jffs2_mark_node_obsolete(c, ref);
-			} else switch(je16_to_cpu(node.u.nodetype) & JFFS2_COMPAT_MASK) {
-			case JFFS2_FEATURE_INCOMPAT:
-				printk(KERN_NOTICE "Unknown INCOMPAT nodetype %04X at %08x\n", je16_to_cpu(node.u.nodetype), ref_offset(ref));
-				/* EEP */
-				BUG();
-				break;
-			case JFFS2_FEATURE_ROCOMPAT:
-				printk(KERN_NOTICE "Unknown ROCOMPAT nodetype %04X at %08x\n", je16_to_cpu(node.u.nodetype), ref_offset(ref));
-				if (!(c->flags & JFFS2_SB_FLAG_RO))
-					BUG();
-				break;
-			case JFFS2_FEATURE_RWCOMPAT_COPY:
-				printk(KERN_NOTICE "Unknown RWCOMPAT_COPY nodetype %04X at %08x\n", je16_to_cpu(node.u.nodetype), ref_offset(ref));
-				break;
-			case JFFS2_FEATURE_RWCOMPAT_DELETE:
-				printk(KERN_NOTICE "Unknown RWCOMPAT_DELETE nodetype %04X at %08x\n", je16_to_cpu(node.u.nodetype), ref_offset(ref));
+
+			err = read_unknown(c, ref, &node.u, retlen);
+			if (err == 1) {
 				jffs2_mark_node_obsolete(c, ref);
 				break;
-			}
+			} else if (unlikely(err))
+				goto free_out;
 
 		}
 		spin_lock(&c->erase_completion_lock);