nodelist.c

linux 内核源代码

		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);
		}
	}
	jffs2_dbg_fragtree_paranoia_check_nolock(f);

	return 0;
}

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;

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

	if (ret && ret->ino != ino)
		ret = NULL;

	return ret;
}

void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
{
	struct jffs2_inode_cache **prev;

	spin_lock(&c->inocache_lock);
	if (!new->ino)
		new->ino = ++c->highest_ino;

	dbg_inocache("add %p (ino #%u)\n", new, new->ino);

	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;

#ifdef CONFIG_JFFS2_FS_XATTR
	BUG_ON(old->xref);
#endif
	dbg_inocache("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;
	}

	/* Free it now unless it's in READING or CLEARING state, which
	   are the transitions upon read_inode() and clear_inode(). The
	   rest of the time we know nobody else is looking at it, and
	   if it's held by read_inode() or clear_inode() they'll free it
	   for themselves. */
	if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING)
		jffs2_free_inode_cache(old);

	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;
			jffs2_xattr_free_inode(c, 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) {
			if (this[REFS_PER_BLOCK].flash_offset == REF_LINK_NODE)
				next = this[REFS_PER_BLOCK].next_in_ino;
			else
				next = NULL;

			jffs2_free_refblock(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;

	dbg_fragtree2("root %p, offset %d\n", fragtree, offset);

	next = fragtree->rb_node;

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

		if (frag->ofs + frag->size <= offset) {
			/* 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) {
			next = frag->rb.rb_left;
		} else {
			return frag;
		}
	}

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

	if (prev)
		dbg_fragtree2("no match. Returning frag %#04x-%#04x, closest previous\n",
			  prev->ofs, prev->ofs+prev->size);
	else
		dbg_fragtree2("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;

	dbg_fragtree("killing\n");

	frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
	while(frag) {
		if (frag->rb.rb_left) {
			frag = frag_left(frag);
			continue;
		}
		if (frag->rb.rb_right) {
			frag = frag_right(frag);
			continue;
		}

		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();
	}
}

struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
					       struct jffs2_eraseblock *jeb,
					       uint32_t ofs, uint32_t len,
					       struct jffs2_inode_cache *ic)
{
	struct jffs2_raw_node_ref *ref;

	BUG_ON(!jeb->allocated_refs);
	jeb->allocated_refs--;

	ref = jeb->last_node;

	dbg_noderef("Last node at %p is (%08x,%p)\n", ref, ref->flash_offset,
		    ref->next_in_ino);

	while (ref->flash_offset != REF_EMPTY_NODE) {
		if (ref->flash_offset == REF_LINK_NODE)
			ref = ref->next_in_ino;
		else
			ref++;
	}

	dbg_noderef("New ref is %p (%08x becomes %08x,%p) len 0x%x\n", ref, 
		    ref->flash_offset, ofs, ref->next_in_ino, len);

	ref->flash_offset = ofs;

	if (!jeb->first_node) {
		jeb->first_node = ref;
		BUG_ON(ref_offset(ref) != jeb->offset);
	} else if (unlikely(ref_offset(ref) != jeb->offset + c->sector_size - jeb->free_size)) {
		uint32_t last_len = ref_totlen(c, jeb, jeb->last_node);

		JFFS2_ERROR("Adding new ref %p at (0x%08x-0x%08x) not immediately after previous (0x%08x-0x%08x)\n",
			    ref, ref_offset(ref), ref_offset(ref)+len,
			    ref_offset(jeb->last_node), 
			    ref_offset(jeb->last_node)+last_len);
		BUG();
	}
	jeb->last_node = ref;

	if (ic) {
		ref->next_in_ino = ic->nodes;
		ic->nodes = ref;
	} else {
		ref->next_in_ino = NULL;
	}

	switch(ref_flags(ref)) {
	case REF_UNCHECKED:
		c->unchecked_size += len;
		jeb->unchecked_size += len;
		break;

	case REF_NORMAL:
	case REF_PRISTINE:
		c->used_size += len;
		jeb->used_size += len;
		break;

	case REF_OBSOLETE:
		c->dirty_size += len;
		jeb->dirty_size += len;
		break;
	}
	c->free_size -= len;
	jeb->free_size -= len;

#ifdef TEST_TOTLEN
	/* Set (and test) __totlen field... for now */
	ref->__totlen = len;
	ref_totlen(c, jeb, ref);
#endif
	return ref;
}

/* No locking, no reservation of 'ref'. Do not use on a live file system */
int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
			   uint32_t size)
{
	if (!size)
		return 0;
	if (unlikely(size > jeb->free_size)) {
		printk(KERN_CRIT "Dirty space 0x%x larger then free_size 0x%x (wasted 0x%x)\n",
		       size, jeb->free_size, jeb->wasted_size);
		BUG();
	}
	/* REF_EMPTY_NODE is !obsolete, so that works OK */
	if (jeb->last_node && ref_obsolete(jeb->last_node)) {
#ifdef TEST_TOTLEN
		jeb->last_node->__totlen += size;
#endif
		c->dirty_size += size;
		c->free_size -= size;
		jeb->dirty_size += size;
		jeb->free_size -= size;
	} else {
		uint32_t ofs = jeb->offset + c->sector_size - jeb->free_size;
		ofs |= REF_OBSOLETE;

		jffs2_link_node_ref(c, jeb, ofs, size, NULL);
	}

	return 0;
}

/* Calculate totlen from surrounding nodes or eraseblock */
static inline uint32_t __ref_totlen(struct jffs2_sb_info *c,
				    struct jffs2_eraseblock *jeb,
				    struct jffs2_raw_node_ref *ref)
{
	uint32_t ref_end;
	struct jffs2_raw_node_ref *next_ref = ref_next(ref);

	if (next_ref)
		ref_end = ref_offset(next_ref);
	else {
		if (!jeb)
			jeb = &c->blocks[ref->flash_offset / c->sector_size];

		/* Last node in block. Use free_space */
		if (unlikely(ref != jeb->last_node)) {
			printk(KERN_CRIT "ref %p @0x%08x is not jeb->last_node (%p @0x%08x)\n",
			       ref, ref_offset(ref), jeb->last_node, jeb->last_node?ref_offset(jeb->last_node):0);
			BUG();
		}
		ref_end = jeb->offset + c->sector_size - jeb->free_size;
	}
	return ref_end - ref_offset(ref);
}

uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
			    struct jffs2_raw_node_ref *ref)
{
	uint32_t ret;

	ret = __ref_totlen(c, jeb, ref);

#ifdef TEST_TOTLEN
	if (unlikely(ret != ref->__totlen)) {
		if (!jeb)
			jeb = &c->blocks[ref->flash_offset / c->sector_size];

		printk(KERN_CRIT "Totlen for ref at %p (0x%08x-0x%08x) miscalculated as 0x%x instead of %x\n",
		       ref, ref_offset(ref), ref_offset(ref)+ref->__totlen,
		       ret, ref->__totlen);
		if (ref_next(ref)) {
			printk(KERN_CRIT "next %p (0x%08x-0x%08x)\n", ref_next(ref), ref_offset(ref_next(ref)),
			       ref_offset(ref_next(ref))+ref->__totlen);
		} else 
			printk(KERN_CRIT "No next ref. jeb->last_node is %p\n", jeb->last_node);

		printk(KERN_CRIT "jeb->wasted_size %x, dirty_size %x, used_size %x, free_size %x\n", jeb->wasted_size, jeb->dirty_size, jeb->used_size, jeb->free_size);

#if defined(JFFS2_DBG_DUMPS) || defined(JFFS2_DBG_PARANOIA_CHECKS)
		__jffs2_dbg_dump_node_refs_nolock(c, jeb);
#endif

		WARN_ON(1);

		ret = ref->__totlen;
	}
#endif /* TEST_TOTLEN */
	return ret;
}