1 files changed, 734 insertions, 93 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 22820f91d2b..e785f0a0632 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -42,6 +42,8 @@ struct pending_extent_op {
 	u64 generation;
 	u64 orig_generation;
 	int level;
+	struct list_head list;
+	int del;
 };
 
 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
@@ -52,6 +54,13 @@ static struct btrfs_block_group_cache *
 __btrfs_find_block_group(struct btrfs_root *root,
 			 struct btrfs_block_group_cache *hint,
 			 u64 search_start, int data, int owner);
+static int pin_down_bytes(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root,
+			  u64 bytenr, u64 num_bytes, int is_data);
+static int update_block_group(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root,
+			      u64 bytenr, u64 num_bytes, int alloc,
+			      int mark_free);
 
 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 {
@@ -559,6 +568,251 @@ out:
 	return ret;
 }
 
+/*
+ * updates all the backrefs that are pending on update_list for the
+ * extent_root
+ */
+static int noinline update_backrefs(struct btrfs_trans_handle *trans,
+				    struct btrfs_root *extent_root,
+				    struct btrfs_path *path,
+				    struct list_head *update_list)
+{
+	struct btrfs_key key;
+	struct btrfs_extent_ref *ref;
+	struct btrfs_fs_info *info = extent_root->fs_info;
+	struct pending_extent_op *op;
+	struct extent_buffer *leaf;
+	int ret = 0;
+	struct list_head *cur = update_list->next;
+	u64 ref_objectid;
+	u64 ref_root = extent_root->root_key.objectid;
+
+	op = list_entry(cur, struct pending_extent_op, list);
+
+search:
+	key.objectid = op->bytenr;
+	key.type = BTRFS_EXTENT_REF_KEY;
+	key.offset = op->orig_parent;
+
+	ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 1);
+	BUG_ON(ret);
+
+	leaf = path->nodes[0];
+
+loop:
+	ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
+
+	ref_objectid = btrfs_ref_objectid(leaf, ref);
+
+	if (btrfs_ref_root(leaf, ref) != ref_root ||
+	    btrfs_ref_generation(leaf, ref) != op->orig_generation ||
+	    (ref_objectid != op->level &&
+	     ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
+		printk(KERN_ERR "couldn't find %Lu, parent %Lu, root %Lu, "
+		       "owner %u\n", op->bytenr, op->orig_parent,
+		       ref_root, op->level);
+		btrfs_print_leaf(extent_root, leaf);
+		BUG();
+	}
+
+	key.objectid = op->bytenr;
+	key.offset = op->parent;
+	key.type = BTRFS_EXTENT_REF_KEY;
+	ret = btrfs_set_item_key_safe(trans, extent_root, path, &key);
+	BUG_ON(ret);
+	ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
+	btrfs_set_ref_generation(leaf, ref, op->generation);
+
+	cur = cur->next;
+
+	list_del_init(&op->list);
+	unlock_extent(&info->extent_ins, op->bytenr,
+		      op->bytenr + op->num_bytes - 1, GFP_NOFS);
+	kfree(op);
+
+	if (cur == update_list) {
+		btrfs_mark_buffer_dirty(path->nodes[0]);
+		btrfs_release_path(extent_root, path);
+		goto out;
+	}
+
+	op = list_entry(cur, struct pending_extent_op, list);
+
+	path->slots[0]++;
+	while (path->slots[0] < btrfs_header_nritems(leaf)) {
+		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+		if (key.objectid == op->bytenr &&
+		    key.type == BTRFS_EXTENT_REF_KEY)
+			goto loop;
+		path->slots[0]++;
+	}
+
+	btrfs_mark_buffer_dirty(path->nodes[0]);
+	btrfs_release_path(extent_root, path);
+	goto search;
+
+out:
+	return 0;
+}
+
+static int noinline insert_extents(struct btrfs_trans_handle *trans,
+				   struct btrfs_root *extent_root,
+				   struct btrfs_path *path,
+				   struct list_head *insert_list, int nr)
+{
+	struct btrfs_key *keys;
+	u32 *data_size;
+	struct pending_extent_op *op;
+	struct extent_buffer *leaf;
+	struct list_head *cur = insert_list->next;
+	struct btrfs_fs_info *info = extent_root->fs_info;
+	u64 ref_root = extent_root->root_key.objectid;
+	int i = 0, last = 0, ret;
+	int total = nr * 2;
+
+	if (!nr)
+		return 0;
+
+	keys = kzalloc(total * sizeof(struct btrfs_key), GFP_NOFS);
+	if (!keys)
+		return -ENOMEM;
+
+	data_size = kzalloc(total * sizeof(u32), GFP_NOFS);
+	if (!data_size) {
+		kfree(keys);
+		return -ENOMEM;
+	}
+
+	list_for_each_entry(op, insert_list, list) {
+		keys[i].objectid = op->bytenr;
+		keys[i].offset = op->num_bytes;
+		keys[i].type = BTRFS_EXTENT_ITEM_KEY;
+		data_size[i] = sizeof(struct btrfs_extent_item);
+		i++;
+
+		keys[i].objectid = op->bytenr;
+		keys[i].offset = op->parent;
+		keys[i].type = BTRFS_EXTENT_REF_KEY;
+		data_size[i] = sizeof(struct btrfs_extent_ref);
+		i++;
+	}
+
+	op = list_entry(cur, struct pending_extent_op, list);
+	i = 0;
+	while (i < total) {
+		int c;
+		ret = btrfs_insert_some_items(trans, extent_root, path,
+					      keys+i, data_size+i, total-i);
+		BUG_ON(ret < 0);
+
+		if (last && ret > 1)
+			BUG();
+
+		leaf = path->nodes[0];
+		for (c = 0; c < ret; c++) {
+			int ref_first = keys[i].type == BTRFS_EXTENT_REF_KEY;
+
+			/*
+			 * if the first item we inserted was a backref, then
+			 * the EXTENT_ITEM will be the odd c's, else it will
+			 * be the even c's
+			 */
+			if ((ref_first && (c % 2)) ||
+			    (!ref_first && !(c % 2))) {
+				struct btrfs_extent_item *itm;
+
+				itm = btrfs_item_ptr(leaf, path->slots[0] + c,
+						     struct btrfs_extent_item);
+				btrfs_set_extent_refs(path->nodes[0], itm, 1);
+				op->del++;
+			} else {
+				struct btrfs_extent_ref *ref;
+
+				ref = btrfs_item_ptr(leaf, path->slots[0] + c,
+						     struct btrfs_extent_ref);
+				btrfs_set_ref_root(leaf, ref, ref_root);
+				btrfs_set_ref_generation(leaf, ref,
+							 op->generation);
+				btrfs_set_ref_objectid(leaf, ref, op->level);
+				btrfs_set_ref_num_refs(leaf, ref, 1);
+				op->del++;
+			}
+
+			/*
+			 * using del to see when its ok to free up the
+			 * pending_extent_op.  In the case where we insert the
+			 * last item on the list in order to help do batching
+			 * we need to not free the extent op until we actually
+			 * insert the extent_item
+			 */
+			if (op->del == 2) {
+				unlock_extent(&info->extent_ins, op->bytenr,
+					      op->bytenr + op->num_bytes - 1,
+					      GFP_NOFS);
+				cur = cur->next;
+				list_del_init(&op->list);
+				kfree(op);
+				if (cur != insert_list)
+					op = list_entry(cur,
+						struct pending_extent_op,
+						list);
+			}
+		}
+		btrfs_mark_buffer_dirty(leaf);
+		btrfs_release_path(extent_root, path);
+
+		/*
+		 * Ok backref's and items usually go right next to eachother,
+		 * but if we could only insert 1 item that means that we
+		 * inserted on the end of a leaf, and we have no idea what may
+		 * be on the next leaf so we just play it safe.  In order to
+		 * try and help this case we insert the last thing on our
+		 * insert list so hopefully it will end up being the last
+		 * thing on the leaf and everything else will be before it,
+		 * which will let us insert a whole bunch of items at the same
+		 * time.
+		 */
+		if (ret == 1 && !last && (i + ret < total)) {
+			/*
+			 * last: where we will pick up the next time around
+			 * i: our current key to insert, will be total - 1
+			 * cur: the current op we are screwing with
+			 * op: duh
+			 */
+			last = i + ret;
+			i = total - 1;
+			cur = insert_list->prev;
+			op = list_entry(cur, struct pending_extent_op, list);
+		} else if (last) {
+			/*
+			 * ok we successfully inserted the last item on the
+			 * list, lets reset everything
+			 *
+			 * i: our current key to insert, so where we left off
+			 *    last time
+			 * last: done with this
+			 * cur: the op we are messing with
+			 * op: duh
+			 * total: since we inserted the last key, we need to
+			 *        decrement total so we dont overflow
+			 */
+			i = last;
+			last = 0;
+			cur = insert_list->next;
+			op = list_entry(cur, struct pending_extent_op, list);
+			total--;
+		} else {
+			i += ret;
+		}
+
+		cond_resched();
+	}
+	ret = 0;
+	kfree(keys);
+	kfree(data_size);
+	return ret;
+}
+
 static int noinline insert_extent_backref(struct btrfs_trans_handle *trans,
 					  struct btrfs_root *root,
 					  struct btrfs_path *path,
@@ -642,6 +896,267 @@ static int noinline remove_extent_backref(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
+static int noinline free_extents(struct btrfs_trans_handle *trans,
+				 struct btrfs_root *extent_root,
+				 struct list_head *del_list)
+{
+	struct btrfs_fs_info *info = extent_root->fs_info;
+	struct btrfs_path *path;
+	struct btrfs_key key, found_key;
+	struct extent_buffer *leaf;
+	struct list_head *cur;
+	struct pending_extent_op *op;
+	struct btrfs_extent_item *ei;
+	int ret, num_to_del, extent_slot = 0, found_extent = 0;
+	u32 refs;
+	u64 bytes_freed = 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+	path->reada = 1;
+
+search:
+	/* search for the backref for the current ref we want to delete */
+	cur = del_list->next;
+	op = list_entry(cur, struct pending_extent_op, list);
+	ret = lookup_extent_backref(trans, extent_root, path, op->bytenr,
+				    op->orig_parent,
+				    extent_root->root_key.objectid,
+				    op->orig_generation, op->level, 1);
+	if (ret) {
+		printk("Unable to find backref byte nr %Lu root %Lu gen %Lu "
+		       "owner %u\n", op->bytenr,
+		       extent_root->root_key.objectid, op->orig_generation,
+		       op->level);
+		btrfs_print_leaf(extent_root, path->nodes[0]);
+		WARN_ON(1);
+		goto out;
+	}
+
+	extent_slot = path->slots[0];
+	num_to_del = 1;
+	found_extent = 0;
+
+	/*
+	 * if we aren't the first item on the leaf we can move back one and see
+	 * if our ref is right next to our extent item
+	 */
+	if (likely(extent_slot)) {
+		extent_slot--;
+		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+				      extent_slot);
+		if (found_key.objectid == op->bytenr &&
+		    found_key.type == BTRFS_EXTENT_ITEM_KEY &&
+		    found_key.offset == op->num_bytes) {
+			num_to_del++;
+			found_extent = 1;
+		}
+	}
+
+	/*
+	 * if we didn't find the extent we need to delete the backref and then
+	 * search for the extent item key so we can update its ref count
+	 */
+	if (!found_extent) {
+		key.objectid = op->bytenr;
+		key.type = BTRFS_EXTENT_ITEM_KEY;
+		key.offset = op->num_bytes;
+
+		ret = remove_extent_backref(trans, extent_root, path);
+		BUG_ON(ret);
+		btrfs_release_path(extent_root, path);
+		ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
+		BUG_ON(ret);
+		extent_slot = path->slots[0];
+	}
+
+	/* this is where we update the ref count for the extent */
+	leaf = path->nodes[0];
+	ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item);
+	refs = btrfs_extent_refs(leaf, ei);
+	BUG_ON(refs == 0);
+	refs--;
+	btrfs_set_extent_refs(leaf, ei, refs);
+
+	btrfs_mark_buffer_dirty(leaf);
+
+	/*
+	 * This extent needs deleting.  The reason cur_slot is extent_slot +
+	 * num_to_del is because extent_slot points to the slot where the extent
+	 * is, and if the backref was not right next to the extent we will be
+	 * deleting at least 1 item, and will want to start searching at the
+	 * slot directly next to extent_slot.  However if we did find the
+	 * backref next to the extent item them we will be deleting at least 2
+	 * items and will want to start searching directly after the ref slot
+	 */
+	if (!refs) {
+		struct list_head *pos, *n, *end;
+		int cur_slot = extent_slot+num_to_del;
+		u64 super_used;
+		u64 root_used;
+
+		path->slots[0] = extent_slot;
+		bytes_freed = op->num_bytes;
+
+		/*
+		 * we need to see if we can delete multiple things at once, so
+		 * start looping through the list of extents we are wanting to
+		 * delete and see if their extent/backref's are right next to
+		 * eachother and the extents only have 1 ref
+		 */
+		for (pos = cur->next; pos != del_list; pos = pos->next) {
+			struct pending_extent_op *tmp;
+
+			tmp = list_entry(pos, struct pending_extent_op, list);
+
+			/* we only want to delete extent+ref at this stage */
+			if (cur_slot >= btrfs_header_nritems(leaf) - 1)
+				break;
+
+			btrfs_item_key_to_cpu(leaf, &found_key, cur_slot);
+			if (found_key.objectid != tmp->bytenr ||
+			    found_key.type != BTRFS_EXTENT_ITEM_KEY ||
+			    found_key.offset != tmp->num_bytes)
+				break;
+
+			/* check to make sure this extent only has one ref */
+			ei = btrfs_item_ptr(leaf, cur_slot,
+					    struct btrfs_extent_item);
+			if (btrfs_extent_refs(leaf, ei) != 1)
+				break;
+
+			btrfs_item_key_to_cpu(leaf, &found_key, cur_slot+1);
+			if (found_key.objectid != tmp->bytenr ||
+			    found_key.type != BTRFS_EXTENT_REF_KEY ||
+			    found_key.offset != tmp->orig_parent)
+				break;
+
+			/*
+			 * the ref is right next to the extent, we can set the
+			 * ref count to 0 since we will delete them both now
+			 */
+			btrfs_set_extent_refs(leaf, ei, 0);
+
+			/* pin down the bytes for this extent */
+			mutex_lock(&info->pinned_mutex);
+			ret = pin_down_bytes(trans, extent_root, tmp->bytenr,
+					     tmp->num_bytes, tmp->level >=
+					     BTRFS_FIRST_FREE_OBJECTID);
+			mutex_unlock(&info->pinned_mutex);
+			BUG_ON(ret < 0);
+
+			/*
+			 * use the del field to tell if we need to go ahead and
+			 * free up the extent when we delete the item or not.
+			 */
+			tmp->del = ret;
+			bytes_freed += tmp->num_bytes;
+
+			num_to_del += 2;
+			cur_slot += 2;
+		}
+		end = pos;
+
+		/* update the free space counters */
+		spin_lock_irq(&info->delalloc_lock);
+		super_used = btrfs_super_bytes_used(&info->super_copy);
+		btrfs_set_super_bytes_used(&info->super_copy,
+					   super_used - bytes_freed);
+		spin_unlock_irq(&info->delalloc_lock);
+
+		root_used = btrfs_root_used(&extent_root->root_item);
+		btrfs_set_root_used(&extent_root->root_item,
+				    root_used - bytes_freed);
+
+		/* delete the items */
+		ret = btrfs_del_items(trans, extent_root, path,
+				      path->slots[0], num_to_del);
+		BUG_ON(ret);
+
+		/*
+		 * loop through the extents we deleted and do the cleanup work
+		 * on them
+		 */
+		for (pos = cur, n = pos->next; pos != end;
+		     pos = n, n = pos->next) {
+			struct pending_extent_op *tmp;
+#ifdef BIO_RW_DISCARD
+			u64 map_length;
+			struct btrfs_multi_bio *multi = NULL;
+#endif
+			tmp = list_entry(pos, struct pending_extent_op, list);
+
+			/*
+			 * remember tmp->del tells us wether or not we pinned
+			 * down the extent
+			 */
+			ret = update_block_group(trans, extent_root,
+						 tmp->bytenr, tmp->num_bytes, 0,
+						 tmp->del);
+			BUG_ON(ret);
+
+#ifdef BIO_RW_DISCARD
+			ret = btrfs_map_block(&info->mapping_tree, READ,
+					      tmp->bytenr, &map_length, &multi,
+					      0);
+			if (!ret) {
+				struct btrfs_bio_stripe *stripe;
+				int i;
+
+				stripe = multi->stripe;
+
+				if (map_length > tmp->num_bytes)
+					map_length = tmp->num_bytes;
+
+				for (i = 0; i < multi->num_stripes;
+				     i++, stripe++)
+					blkdev_issue_discard(stripe->dev->bdev,
+							stripe->physical >> 9,
+							map_length >> 9);
+				kfree(multi);
+			}
+#endif
+			list_del_init(&tmp->list);
+			unlock_extent(&info->extent_ins, tmp->bytenr,
+				      tmp->bytenr + tmp->num_bytes - 1,
+				      GFP_NOFS);
+			kfree(tmp);
+		}
+	} else if (refs && found_extent) {
+		/*
+		 * the ref and extent were right next to eachother, but the
+		 * extent still has a ref, so just free the backref and keep
+		 * going
+		 */
+		ret = remove_extent_backref(trans, extent_root, path);
+		BUG_ON(ret);
+
+		list_del_init(&op->list);
+		unlock_extent(&info->extent_ins, op->bytenr,
+			      op->bytenr + op->num_bytes - 1, GFP_NOFS);
+		kfree(op);
+	} else {
+		/*
+		 * the extent has multiple refs and the backref we were looking
+		 * for was not right next to it, so just unlock and go next,
+		 * we're good to go
+		 */
+		list_del_init(&op->list);
+		unlock_extent(&info->extent_ins, op->bytenr,
+			      op->bytenr + op->num_bytes - 1, GFP_NOFS);
+		kfree(op);
+	}
+
+	btrfs_release_path(extent_root, path);
+	if (!list_empty(del_list))
+		goto search;
+
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root, u64 bytenr,
 				     u64 orig_parent, u64 parent,
@@ -685,6 +1200,8 @@ static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
 			extent_op->generation = ref_generation;
 			extent_op->orig_generation = orig_generation;
 			extent_op->level = (int)owner_objectid;
+			INIT_LIST_HEAD(&extent_op->list);
+			extent_op->del = 0;
 
 			set_extent_bits(&root->fs_info->extent_ins,
 					bytenr, bytenr + num_bytes - 1,
@@ -1426,9 +1943,8 @@ static int update_block_group(struct btrfs_trans_handle *trans,
 
 	while(total) {
 		cache = btrfs_lookup_block_group(info, bytenr);
-		if (!cache) {
+		if (!cache)
 			return -1;
-		}
 		byte_in_group = bytenr - cache->key.objectid;
 		WARN_ON(byte_in_group > cache->key.offset);
 
@@ -1605,102 +2121,176 @@ static int finish_current_insert(struct btrfs_trans_handle *trans,
 	u64 end;
 	u64 priv;
 	u64 search = 0;
+	u64 skipped = 0;
 	struct btrfs_fs_info *info = extent_root->fs_info;
 	struct btrfs_path *path;
-	struct btrfs_extent_ref *ref;
-	struct pending_extent_op *extent_op;
-	struct btrfs_key key;
-	struct btrfs_extent_item extent_item;
+	struct pending_extent_op *extent_op, *tmp;
+	struct list_head insert_list, update_list;
 	int ret;
-	int err = 0;
+	int num_inserts = 0, max_inserts;
 
-	btrfs_set_stack_extent_refs(&extent_item, 1);
 	path = btrfs_alloc_path();
+	INIT_LIST_HEAD(&insert_list);
+	INIT_LIST_HEAD(&update_list);
 
-	while(1) {
-		mutex_lock(&info->extent_ins_mutex);
+	max_inserts = extent_root->leafsize /
+		(2 * sizeof(struct btrfs_key) + 2 * sizeof(struct btrfs_item) +
+		 sizeof(struct btrfs_extent_ref) +
+		 sizeof(struct btrfs_extent_item));
+again:
+	mutex_lock(&info->extent_ins_mutex);
+	while (1) {
 		ret = find_first_extent_bit(&info->extent_ins, search, &start,
 					    &end, EXTENT_WRITEBACK);
 		if (ret) {
-			mutex_unlock(&info->extent_ins_mutex);
-			if (search && all) {
-				search = 0;
+			if (skipped && all && !num_inserts) {
+				skipped = 0;
 				continue;
 			}
+			mutex_unlock(&info->extent_ins_mutex);
 			break;
 		}
 
 		ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS);
 		if (!ret) {
+			skipped = 1;
 			search = end + 1;
-			mutex_unlock(&info->extent_ins_mutex);
-			cond_resched();
+			if (need_resched()) {
+				mutex_unlock(&info->extent_ins_mutex);
+				cond_resched();
+				mutex_lock(&info->extent_ins_mutex);
+			}
 			continue;
 		}
-		BUG_ON(ret < 0);
 
 		ret = get_state_private(&info->extent_ins, start, &priv);
 		BUG_ON(ret);
-		extent_op = (struct pending_extent_op *)(unsigned long)priv;
-
-		mutex_unlock(&info->extent_ins_mutex);
+		extent_op = (struct pending_extent_op *)(unsigned long) priv;
 
 		if (extent_op->type == PENDING_EXTENT_INSERT) {
-			key.objectid = start;
-			key.offset = end + 1 - start;
-			key.type = BTRFS_EXTENT_ITEM_KEY;
-			err = btrfs_insert_item(trans, extent_root, &key,
-					&extent_item, sizeof(extent_item));
-			BUG_ON(err);
+			num_inserts++;
+			list_add_tail(&extent_op->list, &insert_list);
+			search = end + 1;
+			if (num_inserts == max_inserts) {
+				mutex_unlock(&info->extent_ins_mutex);
+				break;
+			}
+		} else if (extent_op->type == PENDING_BACKREF_UPDATE) {
+			list_add_tail(&extent_op->list, &update_list);
+			search = end + 1;
+		} else {
+			BUG();
+		}
+	}
 
-			mutex_lock(&info->extent_ins_mutex);
-			clear_extent_bits(&info->extent_ins, start, end,
-					  EXTENT_WRITEBACK, GFP_NOFS);
-			mutex_unlock(&info->extent_ins_mutex);
+	/*
+	 * process teh update list, clear the writeback bit for it, and if
+	 * somebody marked this thing for deletion then just unlock it and be
+	 * done, the free_extents will handle it
+	 */
+	mutex_lock(&info->extent_ins_mutex);
+	list_for_each_entry_safe(extent_op, tmp, &update_list, list) {
+		clear_extent_bits(&info->extent_ins, extent_op->bytenr,
+				  extent_op->bytenr + extent_op->num_bytes - 1,
+				  EXTENT_WRITEBACK, GFP_NOFS);
+		if (extent_op->del) {
+			list_del_init(&extent_op->list);
+			unlock_extent(&info->extent_ins, extent_op->bytenr,
+				      extent_op->bytenr + extent_op->num_bytes
+				      - 1, GFP_NOFS);
+			kfree(extent_op);
+		}
+	}
+	mutex_unlock(&info->extent_ins_mutex);
 
-			err = insert_extent_backref(trans, extent_root, path,
-						start, extent_op->parent,
-						extent_root->root_key.objectid,
-						extent_op->generation,
-						extent_op->level);
-			BUG_ON(err);
-		} else if (extent_op->type == PENDING_BACKREF_UPDATE) {
-			err = lookup_extent_backref(trans, extent_root, path,
-						start, extent_op->orig_parent,
-						extent_root->root_key.objectid,
-						extent_op->orig_generation,
-						extent_op->level, 0);
-			BUG_ON(err);
+	/*
+	 * still have things left on the update list, go ahead an update
+	 * everything
+	 */
+	if (!list_empty(&update_list)) {
+		ret = update_backrefs(trans, extent_root, path, &update_list);
+		BUG_ON(ret);
+	}
 
-			mutex_lock(&info->extent_ins_mutex);
-			clear_extent_bits(&info->extent_ins, start, end,
-					  EXTENT_WRITEBACK, GFP_NOFS);
-			mutex_unlock(&info->extent_ins_mutex);
+	/*
+	 * if no inserts need to be done, but we skipped some extents and we
+	 * need to make sure everything is cleaned then reset everything and
+	 * go back to the beginning
+	 */
+	if (!num_inserts && all && skipped) {
+		search = 0;
+		skipped = 0;
+		INIT_LIST_HEAD(&update_list);
+		INIT_LIST_HEAD(&insert_list);
+		goto again;
+	} else if (!num_inserts) {
+		goto out;
+	}
 
-			key.objectid = start;
-			key.offset = extent_op->parent;
-			key.type = BTRFS_EXTENT_REF_KEY;
-			err = btrfs_set_item_key_safe(trans, extent_root, path,
-						      &key);
-			BUG_ON(err);
-			ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
-					     struct btrfs_extent_ref);
-			btrfs_set_ref_generation(path->nodes[0], ref,
-						 extent_op->generation);
-			btrfs_mark_buffer_dirty(path->nodes[0]);
-			btrfs_release_path(extent_root, path);
-		} else {
-			BUG_ON(1);
+	/*
+	 * process the insert extents list.  Again if we are deleting this
+	 * extent, then just unlock it, pin down the bytes if need be, and be
+	 * done with it.  Saves us from having to actually insert the extent
+	 * into the tree and then subsequently come along and delete it
+	 */
+	mutex_lock(&info->extent_ins_mutex);
+	list_for_each_entry_safe(extent_op, tmp, &insert_list, list) {
+		clear_extent_bits(&info->extent_ins, extent_op->bytenr,
+				  extent_op->bytenr + extent_op->num_bytes - 1,
+				  EXTENT_WRITEBACK, GFP_NOFS);
+		if (extent_op->del) {
+			list_del_init(&extent_op->list);
+			unlock_extent(&info->extent_ins, extent_op->bytenr,
+				      extent_op->bytenr + extent_op->num_bytes
+				      - 1, GFP_NOFS);
+
+			mutex_lock(&extent_root->fs_info->pinned_mutex);
+			ret = pin_down_bytes(trans, extent_root,
+					     extent_op->bytenr,
+					     extent_op->num_bytes, 0);
+			mutex_unlock(&extent_root->fs_info->pinned_mutex);
+
+			ret = update_block_group(trans, extent_root,
+						 extent_op->bytenr,
+						 extent_op->num_bytes,
+						 0, ret > 0);
+			BUG_ON(ret);
+			kfree(extent_op);
+			num_inserts--;
 		}
-		kfree(extent_op);
-		unlock_extent(&info->extent_ins, start, end, GFP_NOFS);
-		if (all)
-			search = 0;
-		else
-			search = end + 1;
+	}
+	mutex_unlock(&info->extent_ins_mutex);
 
-		cond_resched();
+	ret = insert_extents(trans, extent_root, path, &insert_list,
+			     num_inserts);
+	BUG_ON(ret);
+
+	/*
+	 * if we broke out of the loop in order to insert stuff because we hit
+	 * the maximum number of inserts at a time we can handle, then loop
+	 * back and pick up where we left off
+	 */
+	if (num_inserts == max_inserts) {
+		INIT_LIST_HEAD(&insert_list);
+		INIT_LIST_HEAD(&update_list);
+		num_inserts = 0;
+		goto again;
 	}
+
+	/*
+	 * again, if we need to make absolutely sure there are no more pending
+	 * extent operations left and we know that we skipped some, go back to
+	 * the beginning and do it all again
+	 */
+	if (all && skipped) {
+		INIT_LIST_HEAD(&insert_list);
+		INIT_LIST_HEAD(&update_list);
+		search = 0;
+		skipped = 0;
+		num_inserts = 0;
+		goto again;
+	}
+out:
 	btrfs_free_path(path);
 	return 0;
 }
@@ -1802,6 +2392,12 @@ static int __free_extent(struct btrfs_trans_handle *trans,
 			btrfs_release_path(extent_root, path);
 			ret = btrfs_search_slot(trans, extent_root,
 						&key, path, -1, 1);
+			if (ret) {
+				printk(KERN_ERR "umm, got %d back from search"
+				       ", was looking for %Lu\n", ret,
+				       bytenr);
+				btrfs_print_leaf(extent_root, path->nodes[0]);
+			}
 			BUG_ON(ret);
 			extent_slot = path->slots[0];
 		}
@@ -1921,32 +2517,42 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct
 	u64 end;
 	u64 priv;
 	u64 search = 0;
+	int nr = 0, skipped = 0;
 	struct extent_io_tree *pending_del;
 	struct extent_io_tree *extent_ins;
 	struct pending_extent_op *extent_op;
 	struct btrfs_fs_info *info = extent_root->fs_info;
+	struct list_head delete_list;
 
+	INIT_LIST_HEAD(&delete_list);
 	extent_ins = &extent_root->fs_info->extent_ins;
 	pending_del = &extent_root->fs_info->pending_del;
 
+again:
+	mutex_lock(&info->extent_ins_mutex);
 	while(1) {
-		mutex_lock(&info->extent_ins_mutex);
 		ret = find_first_extent_bit(pending_del, search, &start, &end,
 					    EXTENT_WRITEBACK);
 		if (ret) {
-			mutex_unlock(&info->extent_ins_mutex);
-			if (all && search) {
+			if (all && skipped && !nr) {
 				search = 0;
 				continue;
 			}
+			mutex_unlock(&info->extent_ins_mutex);
 			break;
 		}
 
 		ret = try_lock_extent(extent_ins, start, end, GFP_NOFS);
 		if (!ret) {
 			search = end+1;
-			mutex_unlock(&info->extent_ins_mutex);
-			cond_resched();
+			skipped = 1;
+
+			if (need_resched()) {
+				mutex_unlock(&info->extent_ins_mutex);
+				cond_resched();
+				mutex_lock(&info->extent_ins_mutex);
+			}
+
 			continue;
 		}
 		BUG_ON(ret < 0);
@@ -1959,15 +2565,8 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct
 				  GFP_NOFS);
 		if (!test_range_bit(extent_ins, start, end,
 				    EXTENT_WRITEBACK, 0)) {
-			mutex_unlock(&info->extent_ins_mutex);
-free_extent:
-			ret = __free_extent(trans, extent_root,
-					    start, end + 1 - start,
-					    extent_op->orig_parent,
-					    extent_root->root_key.objectid,
-					    extent_op->orig_generation,
-					    extent_op->level, 1, 0);
-			kfree(extent_op);
+			list_add_tail(&extent_op->list, &delete_list);
+			nr++;
 		} else {
 			kfree(extent_op);
 
@@ -1980,10 +2579,12 @@ free_extent:
 			clear_extent_bits(&info->extent_ins, start, end,
 					  EXTENT_WRITEBACK, GFP_NOFS);
 
-			mutex_unlock(&info->extent_ins_mutex);
-
-			if (extent_op->type == PENDING_BACKREF_UPDATE)
-				goto free_extent;
+			if (extent_op->type == PENDING_BACKREF_UPDATE) {
+				list_add_tail(&extent_op->list, &delete_list);
+				search = end + 1;
+				nr++;
+				continue;
+			}
 
 			mutex_lock(&extent_root->fs_info->pinned_mutex);
 			ret = pin_down_bytes(trans, extent_root, start,
@@ -1993,19 +2594,34 @@ free_extent:
 			ret = update_block_group(trans, extent_root, start,
 						end + 1 - start, 0, ret > 0);
 
+			unlock_extent(extent_ins, start, end, GFP_NOFS);
 			BUG_ON(ret);
 			kfree(extent_op);
 		}
 		if (ret)
 			err = ret;
-		unlock_extent(extent_ins, start, end, GFP_NOFS);
 
-		if (all)
-			search = 0;
-		else
-			search = end + 1;
-		cond_resched();
+		search = end + 1;
+
+		if (need_resched()) {
+			mutex_unlock(&info->extent_ins_mutex);
+			cond_resched();
+			mutex_lock(&info->extent_ins_mutex);
+		}
 	}
+
+	if (nr) {
+		ret = free_extents(trans, extent_root, &delete_list);
+		BUG_ON(ret);
+	}
+
+	if (all && skipped) {
+		INIT_LIST_HEAD(&delete_list);
+		search = 0;
+		nr = 0;
+		goto again;
+	}
+
 	return err;
 }
 
@@ -2024,7 +2640,29 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 
 	WARN_ON(num_bytes < root->sectorsize);
 	if (root == extent_root) {
-		struct pending_extent_op *extent_op;
+		struct pending_extent_op *extent_op = NULL;
+
+		mutex_lock(&root->fs_info->extent_ins_mutex);
+		if (test_range_bit(&root->fs_info->extent_ins, bytenr,
+				bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
+			u64 priv;
+			ret = get_state_private(&root->fs_info->extent_ins,
+						bytenr, &priv);
+			BUG_ON(ret);
+			extent_op = (struct pending_extent_op *)
+						(unsigned long)priv;
+
+			extent_op->del = 1;
+			if (extent_op->type == PENDING_EXTENT_INSERT) {
+				mutex_unlock(&root->fs_info->extent_ins_mutex);
+				return 0;
+			}
+		}
+
+		if (extent_op) {
+			ref_generation = extent_op->orig_generation;
+			parent = extent_op->orig_parent;
+		}
 
 		extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
 		BUG_ON(!extent_op);
@@ -2037,8 +2675,9 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 		extent_op->generation = ref_generation;
 		extent_op->orig_generation = ref_generation;
 		extent_op->level = (int)owner_objectid;
+		INIT_LIST_HEAD(&extent_op->list);
+		extent_op->del = 0;
 
-		mutex_lock(&root->fs_info->extent_ins_mutex);
 		set_extent_bits(&root->fs_info->pending_del,
 				bytenr, bytenr + num_bytes - 1,
 				EXTENT_WRITEBACK, GFP_NOFS);
@@ -2515,6 +3154,8 @@ static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
 		extent_op->generation = ref_generation;
 		extent_op->orig_generation = 0;
 		extent_op->level = (int)owner;
+		INIT_LIST_HEAD(&extent_op->list);
+		extent_op->del = 0;
 
 		mutex_lock(&root->fs_info->extent_ins_mutex);
 		set_extent_bits(&root->fs_info->extent_ins, ins->objectid,