nodelist.c

jffs2源代码基于2。6内核

				   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;
				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_list(tn, &ret_tn);
			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);
			}
			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));
				jffs2_mark_node_obsolete(c, ref);
				break;
			}

		}
		spin_lock(&c->erase_completion_lock);

	}
	spin_unlock(&c->erase_completion_lock);
	*tnp = ret_tn;
	*fdp = ret_fd;

	return 0;

 free_out:
	jffs2_free_tmp_dnode_info_list(ret_tn);
	jffs2_free_full_dirent_list(ret_fd);
	return err;
}

void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state)
{
	spin_lock(&c->inocache_lock);
	ic->state = state;
	wake_up(&c->inocache_wq);
	spin_unlock(&c->inocache_lock);
}

/* During mount, this needs no locking. During normal operation, its
   callers want to do other stuff while still holding the inocache_lock.
   Rather than introducing special case get_ino_cache functions or 
   callbacks, we just let the caller do the locking itself. */
   
struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
{
	struct jffs2_inode_cache *ret;

	D2(printk(KERN_DEBUG "jffs2_get_ino_cache(): ino %u\n", ino));

	ret = c->inocache_list[ino % INOCACHE_HASHSIZE];
	while (ret && ret->ino < ino) {
		ret = ret->next;
	}
	
	if (ret && ret->ino != ino)
		ret = NULL;

	D2(printk(KERN_DEBUG "jffs2_get_ino_cache found %p for ino %u\n", ret, ino));
	return ret;
}

void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
{
	struct jffs2_inode_cache **prev;
	D2(printk(KERN_DEBUG "jffs2_add_ino_cache: Add %p (ino #%u)\n", new, new->ino));
	spin_lock(&c->inocache_lock);
	
	prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE];

	while ((*prev) && (*prev)->ino < new->ino) {
		prev = &(*prev)->next;
	}
	new->next = *prev;
	*prev = new;

	spin_unlock(&c->inocache_lock);
}

void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
{
	struct jffs2_inode_cache **prev;
	D2(printk(KERN_DEBUG "jffs2_del_ino_cache: Del %p (ino #%u)\n", old, old->ino));
	spin_lock(&c->inocache_lock);
	
	prev = &c->inocache_list[old->ino % INOCACHE_HASHSIZE];
	
	while ((*prev) && (*prev)->ino < old->ino) {
		prev = &(*prev)->next;
	}
	if ((*prev) == old) {
		*prev = old->next;
	}

	spin_unlock(&c->inocache_lock);
}

void jffs2_free_ino_caches(struct jffs2_sb_info *c)
{
	int i;
	struct jffs2_inode_cache *this, *next;
	
	for (i=0; i<INOCACHE_HASHSIZE; i++) {
		this = c->inocache_list[i];
		while (this) {
			next = this->next;
			D2(printk(KERN_DEBUG "jffs2_free_ino_caches: Freeing ino #%u at %p\n", this->ino, this));
			jffs2_free_inode_cache(this);
			this = next;
		}
		c->inocache_list[i] = NULL;
	}
}

void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
{
	int i;
	struct jffs2_raw_node_ref *this, *next;

	for (i=0; i<c->nr_blocks; i++) {
		this = c->blocks[i].first_node;
		while(this) {
			next = this->next_phys;
			jffs2_free_raw_node_ref(this);
			this = next;
		}
		c->blocks[i].first_node = c->blocks[i].last_node = NULL;
	}
}
	
struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
{
	/* The common case in lookup is that there will be a node 
	   which precisely matches. So we go looking for that first */
	struct rb_node *next;
	struct jffs2_node_frag *prev = NULL;
	struct jffs2_node_frag *frag = NULL;

	D2(printk(KERN_DEBUG "jffs2_lookup_node_frag(%p, %d)\n", fragtree, offset));

	next = fragtree->rb_node;

	while(next) {
		frag = rb_entry(next, struct jffs2_node_frag, rb);

		D2(printk(KERN_DEBUG "Considering frag %d-%d (%p). left %p, right %p\n",
			  frag->ofs, frag->ofs+frag->size, frag, frag->rb.rb_left, frag->rb.rb_right));
		if (frag->ofs + frag->size <= offset) {
			D2(printk(KERN_DEBUG "Going right from frag %d-%d, before the region we care about\n",
				  frag->ofs, frag->ofs+frag->size));
			/* Remember the closest smaller match on the way down */
			if (!prev || frag->ofs > prev->ofs)
				prev = frag;
			next = frag->rb.rb_right;
		} else if (frag->ofs > offset) {
			D2(printk(KERN_DEBUG "Going left from frag %d-%d, after the region we care about\n",
				  frag->ofs, frag->ofs+frag->size));
			next = frag->rb.rb_left;
		} else {
			D2(printk(KERN_DEBUG "Returning frag %d,%d, matched\n",
				  frag->ofs, frag->ofs+frag->size));
			return frag;
		}
	}

	/* Exact match not found. Go back up looking at each parent,
	   and return the closest smaller one */

	if (prev)
		D2(printk(KERN_DEBUG "No match. Returning frag %d,%d, closest previous\n",
			  prev->ofs, prev->ofs+prev->size));
	else 
		D2(printk(KERN_DEBUG "Returning NULL, empty fragtree\n"));
	
	return prev;
}

/* Pass 'c' argument to indicate that nodes should be marked obsolete as
   they're killed. */
void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
{
	struct jffs2_node_frag *frag;
	struct jffs2_node_frag *parent;

	if (!root->rb_node)
		return;

	frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));

	while(frag) {
		if (frag->rb.rb_left) {
			D2(printk(KERN_DEBUG "Going left from frag (%p) %d-%d\n", 
				  frag, frag->ofs, frag->ofs+frag->size));
			frag = frag_left(frag);
			continue;
		}
		if (frag->rb.rb_right) {
			D2(printk(KERN_DEBUG "Going right from frag (%p) %d-%d\n", 
				  frag, frag->ofs, frag->ofs+frag->size));
			frag = frag_right(frag);
			continue;
		}

		D2(printk(KERN_DEBUG "jffs2_kill_fragtree: frag at 0x%x-0x%x: node %p, frags %d--\n",
			  frag->ofs, frag->ofs+frag->size, frag->node,
			  frag->node?frag->node->frags:0));
			
		if (frag->node && !(--frag->node->frags)) {
			/* Not a hole, and it's the final remaining frag 
			   of this node. Free the node */
			if (c)
				jffs2_mark_node_obsolete(c, frag->node->raw);
			
			jffs2_free_full_dnode(frag->node);
		}
		parent = frag_parent(frag);
		if (parent) {
			if (frag_left(parent) == frag)
				parent->rb.rb_left = NULL;
			else 
				parent->rb.rb_right = NULL;
		}

		jffs2_free_node_frag(frag);
		frag = parent;

		cond_resched();
	}
}

void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base)
{
	struct rb_node *parent = &base->rb;
	struct rb_node **link = &parent;

	D2(printk(KERN_DEBUG "jffs2_fragtree_insert(%p; %d-%d, %p)\n", newfrag, 
		  newfrag->ofs, newfrag->ofs+newfrag->size, base));

	while (*link) {
		parent = *link;
		base = rb_entry(parent, struct jffs2_node_frag, rb);
	
		D2(printk(KERN_DEBUG "fragtree_insert considering frag at 0x%x\n", base->ofs));
		if (newfrag->ofs > base->ofs)
			link = &base->rb.rb_right;
		else if (newfrag->ofs < base->ofs)
			link = &base->rb.rb_left;
		else {
			printk(KERN_CRIT "Duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
			BUG();
		}
	}

	rb_link_node(&newfrag->rb, &base->rb, link);
}