1 files changed, 241 insertions, 206 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 6d183f60d63..eea5da7a2b9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -38,8 +38,7 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
 			      struct extent_buffer *dst_buf,
 			      struct extent_buffer *src_buf);
 static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		    struct btrfs_path *path, int level, int slot,
-		    int tree_mod_log);
+		    struct btrfs_path *path, int level, int slot);
 static void tree_mod_log_free_eb(struct btrfs_fs_info *fs_info,
 				 struct extent_buffer *eb);
 struct extent_buffer *read_old_tree_block(struct btrfs_root *root, u64 bytenr,
@@ -596,6 +595,11 @@ tree_mod_log_insert_move(struct btrfs_fs_info *fs_info,
 	if (tree_mod_dont_log(fs_info, eb))
 		return 0;
 
+	/*
+	 * When we override something during the move, we log these removals.
+	 * This can only happen when we move towards the beginning of the
+	 * buffer, i.e. dst_slot < src_slot.
+	 */
 	for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) {
 		ret = tree_mod_log_insert_key_locked(fs_info, eb, i + dst_slot,
 					      MOD_LOG_KEY_REMOVE_WHILE_MOVING);
@@ -647,8 +651,6 @@ tree_mod_log_insert_root(struct btrfs_fs_info *fs_info,
 	if (tree_mod_dont_log(fs_info, NULL))
 		return 0;
 
-	__tree_mod_log_free_eb(fs_info, old_root);
-
 	ret = tree_mod_alloc(fs_info, flags, &tm);
 	if (ret < 0)
 		goto out;
@@ -773,8 +775,7 @@ tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst,
 
 static noinline void
 tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info,
-			  struct extent_buffer *eb,
-			  struct btrfs_disk_key *disk_key, int slot, int atomic)
+			  struct extent_buffer *eb, int slot, int atomic)
 {
 	int ret;
 
@@ -926,12 +927,7 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
 			ret = btrfs_dec_ref(trans, root, buf, 1, 1);
 			BUG_ON(ret); /* -ENOMEM */
 		}
-		/*
-		 * don't log freeing in case we're freeing the root node, this
-		 * is done by tree_mod_log_set_root_pointer later
-		 */
-		if (buf != root->node && btrfs_header_level(buf) != 0)
-			tree_mod_log_free_eb(root->fs_info, buf);
+		tree_mod_log_free_eb(root->fs_info, buf);
 		clean_tree_block(trans, root, buf);
 		*last_ref = 1;
 	}
@@ -1225,6 +1221,8 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb,
 	free_extent_buffer(eb);
 
 	__tree_mod_log_rewind(eb_rewin, time_seq, tm);
+	WARN_ON(btrfs_header_nritems(eb_rewin) >
+		BTRFS_NODEPTRS_PER_BLOCK(fs_info->fs_root));
 
 	return eb_rewin;
 }
@@ -1241,9 +1239,11 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 {
 	struct tree_mod_elem *tm;
 	struct extent_buffer *eb;
+	struct extent_buffer *old;
 	struct tree_mod_root *old_root = NULL;
 	u64 old_generation = 0;
 	u64 logical;
+	u32 blocksize;
 
 	eb = btrfs_read_lock_root_node(root);
 	tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq);
@@ -1259,14 +1259,32 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 	}
 
 	tm = tree_mod_log_search(root->fs_info, logical, time_seq);
-	if (old_root)
+	if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
+		btrfs_tree_read_unlock(root->node);
+		free_extent_buffer(root->node);
+		blocksize = btrfs_level_size(root, old_root->level);
+		old = read_tree_block(root, logical, blocksize, 0);
+		if (!old) {
+			pr_warn("btrfs: failed to read tree block %llu from get_old_root\n",
+				logical);
+			WARN_ON(1);
+		} else {
+			eb = btrfs_clone_extent_buffer(old);
+			free_extent_buffer(old);
+		}
+	} else if (old_root) {
+		btrfs_tree_read_unlock(root->node);
+		free_extent_buffer(root->node);
 		eb = alloc_dummy_extent_buffer(logical, root->nodesize);
-	else
+	} else {
 		eb = btrfs_clone_extent_buffer(root->node);
-	btrfs_tree_read_unlock(root->node);
-	free_extent_buffer(root->node);
+		btrfs_tree_read_unlock(root->node);
+		free_extent_buffer(root->node);
+	}
+
 	if (!eb)
 		return NULL;
+	extent_buffer_get(eb);
 	btrfs_tree_read_lock(eb);
 	if (old_root) {
 		btrfs_set_header_bytenr(eb, eb->start);
@@ -1279,11 +1297,28 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 		__tree_mod_log_rewind(eb, time_seq, tm);
 	else
 		WARN_ON(btrfs_header_level(eb) != 0);
-	extent_buffer_get(eb);
+	WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root));
 
 	return eb;
 }
 
+int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq)
+{
+	struct tree_mod_elem *tm;
+	int level;
+
+	tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq);
+	if (tm && tm->op == MOD_LOG_ROOT_REPLACE) {
+		level = tm->old_root.level;
+	} else {
+		rcu_read_lock();
+		level = btrfs_header_level(root->node);
+		rcu_read_unlock();
+	}
+
+	return level;
+}
+
 static inline int should_cow_block(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root,
 				   struct extent_buffer *buf)
@@ -1324,19 +1359,16 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
 	u64 search_start;
 	int ret;
 
-	if (trans->transaction != root->fs_info->running_transaction) {
-		printk(KERN_CRIT "trans %llu running %llu\n",
+	if (trans->transaction != root->fs_info->running_transaction)
+		WARN(1, KERN_CRIT "trans %llu running %llu\n",
 		       (unsigned long long)trans->transid,
 		       (unsigned long long)
 		       root->fs_info->running_transaction->transid);
-		WARN_ON(1);
-	}
-	if (trans->transid != root->fs_info->generation) {
-		printk(KERN_CRIT "trans %llu running %llu\n",
+
+	if (trans->transid != root->fs_info->generation)
+		WARN(1, KERN_CRIT "trans %llu running %llu\n",
 		       (unsigned long long)trans->transid,
 		       (unsigned long long)root->fs_info->generation);
-		WARN_ON(1);
-	}
 
 	if (!should_cow_block(trans, root, buf)) {
 		*cow_ret = buf;
@@ -1432,10 +1464,8 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
 	if (cache_only && parent_level != 1)
 		return 0;
 
-	if (trans->transaction != root->fs_info->running_transaction)
-		WARN_ON(1);
-	if (trans->transid != root->fs_info->generation)
-		WARN_ON(1);
+	WARN_ON(trans->transaction != root->fs_info->running_transaction);
+	WARN_ON(trans->transid != root->fs_info->generation);
 
 	parent_nritems = btrfs_header_nritems(parent);
 	blocksize = btrfs_level_size(root, parent_level - 1);
@@ -1725,6 +1755,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 			goto enospc;
 		}
 
+		tree_mod_log_free_eb(root->fs_info, root->node);
 		tree_mod_log_set_root_pointer(root, child);
 		rcu_assign_pointer(root->node, child);
 
@@ -1789,7 +1820,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		if (btrfs_header_nritems(right) == 0) {
 			clean_tree_block(trans, root, right);
 			btrfs_tree_unlock(right);
-			del_ptr(trans, root, path, level + 1, pslot + 1, 1);
+			del_ptr(trans, root, path, level + 1, pslot + 1);
 			root_sub_used(root, right->len);
 			btrfs_free_tree_block(trans, root, right, 0, 1);
 			free_extent_buffer_stale(right);
@@ -1798,7 +1829,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 			struct btrfs_disk_key right_key;
 			btrfs_node_key(right, &right_key, 0);
 			tree_mod_log_set_node_key(root->fs_info, parent,
-						  &right_key, pslot + 1, 0);
+						  pslot + 1, 0);
 			btrfs_set_node_key(parent, &right_key, pslot + 1);
 			btrfs_mark_buffer_dirty(parent);
 		}
@@ -1833,7 +1864,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 	if (btrfs_header_nritems(mid) == 0) {
 		clean_tree_block(trans, root, mid);
 		btrfs_tree_unlock(mid);
-		del_ptr(trans, root, path, level + 1, pslot, 1);
+		del_ptr(trans, root, path, level + 1, pslot);
 		root_sub_used(root, mid->len);
 		btrfs_free_tree_block(trans, root, mid, 0, 1);
 		free_extent_buffer_stale(mid);
@@ -1842,7 +1873,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		/* update the parent key to reflect our changes */
 		struct btrfs_disk_key mid_key;
 		btrfs_node_key(mid, &mid_key, 0);
-		tree_mod_log_set_node_key(root->fs_info, parent, &mid_key,
+		tree_mod_log_set_node_key(root->fs_info, parent,
 					  pslot, 0);
 		btrfs_set_node_key(parent, &mid_key, pslot);
 		btrfs_mark_buffer_dirty(parent);
@@ -1942,7 +1973,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 			orig_slot += left_nr;
 			btrfs_node_key(mid, &disk_key, 0);
 			tree_mod_log_set_node_key(root->fs_info, parent,
-						  &disk_key, pslot, 0);
+						  pslot, 0);
 			btrfs_set_node_key(parent, &disk_key, pslot);
 			btrfs_mark_buffer_dirty(parent);
 			if (btrfs_header_nritems(left) > orig_slot) {
@@ -1995,7 +2026,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 
 			btrfs_node_key(right, &disk_key, 0);
 			tree_mod_log_set_node_key(root->fs_info, parent,
-						  &disk_key, pslot + 1, 0);
+						  pslot + 1, 0);
 			btrfs_set_node_key(parent, &disk_key, pslot + 1);
 			btrfs_mark_buffer_dirty(parent);
 
@@ -2181,6 +2212,9 @@ static noinline void unlock_up(struct btrfs_path *path, int level,
 	int no_skips = 0;
 	struct extent_buffer *t;
 
+	if (path->really_keep_locks)
+		return;
+
 	for (i = level; i < BTRFS_MAX_LEVEL; i++) {
 		if (!path->nodes[i])
 			break;
@@ -2228,7 +2262,7 @@ noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
 {
 	int i;
 
-	if (path->keep_locks)
+	if (path->keep_locks || path->really_keep_locks)
 		return;
 
 	for (i = level; i < BTRFS_MAX_LEVEL; i++) {
@@ -2461,7 +2495,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (!cow)
 		write_lock_level = -1;
 
-	if (cow && (p->keep_locks || p->lowest_level))
+	if (cow && (p->really_keep_locks || p->keep_locks || p->lowest_level))
 		write_lock_level = BTRFS_MAX_LEVEL;
 
 	min_write_lock_level = write_lock_level;
@@ -2530,7 +2564,10 @@ again:
 			 * must have write locks on this node and the
 			 * parent
 			 */
-			if (level + 1 > write_lock_level) {
+			if (level > write_lock_level ||
+			    (level + 1 > write_lock_level &&
+			    level + 1 < BTRFS_MAX_LEVEL &&
+			    p->nodes[level + 1])) {
 				write_lock_level = level + 1;
 				btrfs_release_path(p);
 				goto again;
@@ -2879,7 +2916,7 @@ static void fixup_low_keys(struct btrfs_trans_handle *trans,
 		if (!path->nodes[i])
 			break;
 		t = path->nodes[i];
-		tree_mod_log_set_node_key(root->fs_info, t, key, tslot, 1);
+		tree_mod_log_set_node_key(root->fs_info, t, tslot, 1);
 		btrfs_set_node_key(t, key, tslot);
 		btrfs_mark_buffer_dirty(path->nodes[i]);
 		if (tslot != 0)
@@ -2970,8 +3007,10 @@ static int push_node_left(struct btrfs_trans_handle *trans,
 			   push_items * sizeof(struct btrfs_key_ptr));
 
 	if (push_items < src_nritems) {
-		tree_mod_log_eb_move(root->fs_info, src, 0, push_items,
-				     src_nritems - push_items);
+		/*
+		 * don't call tree_mod_log_eb_move here, key removal was already
+		 * fully logged by tree_mod_log_eb_copy above.
+		 */
 		memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
 				      btrfs_node_key_ptr_offset(push_items),
 				      (src_nritems - push_items) *
@@ -3262,14 +3301,21 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
  */
 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
 {
+	struct btrfs_item *start_item;
+	struct btrfs_item *end_item;
+	struct btrfs_map_token token;
 	int data_len;
 	int nritems = btrfs_header_nritems(l);
 	int end = min(nritems, start + nr) - 1;
 
 	if (!nr)
 		return 0;
-	data_len = btrfs_item_end_nr(l, start);
-	data_len = data_len - btrfs_item_offset_nr(l, end);
+	btrfs_init_map_token(&token);
+	start_item = btrfs_item_nr(l, start);
+	end_item = btrfs_item_nr(l, end);
+	data_len = btrfs_token_item_offset(l, start_item, &token) +
+		btrfs_token_item_size(l, start_item, &token);
+	data_len = data_len - btrfs_token_item_offset(l, end_item, &token);
 	data_len += sizeof(struct btrfs_item) * nr;
 	WARN_ON(data_len < 0);
 	return data_len;
@@ -3363,8 +3409,7 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
 	if (push_items == 0)
 		goto out_unlock;
 
-	if (!empty && push_items == left_nritems)
-		WARN_ON(1);
+	WARN_ON(!empty && push_items == left_nritems);
 
 	/* push left to right */
 	right_nritems = btrfs_header_nritems(right);
@@ -3602,11 +3647,9 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
 	btrfs_set_header_nritems(left, old_left_nritems + push_items);
 
 	/* fixup right node */
-	if (push_items > right_nritems) {
-		printk(KERN_CRIT "push items %d nr %u\n", push_items,
+	if (push_items > right_nritems)
+		WARN(1, KERN_CRIT "push items %d nr %u\n", push_items,
 		       right_nritems);
-		WARN_ON(1);
-	}
 
 	if (push_items < right_nritems) {
 		push_space = btrfs_item_offset_nr(right, push_items - 1) -
@@ -4402,149 +4445,6 @@ void btrfs_extend_item(struct btrfs_trans_handle *trans,
 }
 
 /*
- * Given a key and some data, insert items into the tree.
- * This does all the path init required, making room in the tree if needed.
- * Returns the number of keys that were inserted.
- */
-int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root,
-			    struct btrfs_path *path,
-			    struct btrfs_key *cpu_key, u32 *data_size,
-			    int nr)
-{
-	struct extent_buffer *leaf;
-	struct btrfs_item *item;
-	int ret = 0;
-	int slot;
-	int i;
-	u32 nritems;
-	u32 total_data = 0;
-	u32 total_size = 0;
-	unsigned int data_end;
-	struct btrfs_disk_key disk_key;
-	struct btrfs_key found_key;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-
-	for (i = 0; i < nr; i++) {
-		if (total_size + data_size[i] + sizeof(struct btrfs_item) >
-		    BTRFS_LEAF_DATA_SIZE(root)) {
-			break;
-			nr = i;
-		}
-		total_data += data_size[i];
-		total_size += data_size[i] + sizeof(struct btrfs_item);
-	}
-	BUG_ON(nr == 0);
-
-	ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
-	if (ret == 0)
-		return -EEXIST;
-	if (ret < 0)
-		goto out;
-
-	leaf = path->nodes[0];
-
-	nritems = btrfs_header_nritems(leaf);
-	data_end = leaf_data_end(root, leaf);
-
-	if (btrfs_leaf_free_space(root, leaf) < total_size) {
-		for (i = nr; i >= 0; i--) {
-			total_data -= data_size[i];
-			total_size -= data_size[i] + sizeof(struct btrfs_item);
-			if (total_size < btrfs_leaf_free_space(root, leaf))
-				break;
-		}
-		nr = i;
-	}
-
-	slot = path->slots[0];
-	BUG_ON(slot < 0);
-
-	if (slot != nritems) {
-		unsigned int old_data = btrfs_item_end_nr(leaf, slot);
-
-		item = btrfs_item_nr(leaf, slot);
-		btrfs_item_key_to_cpu(leaf, &found_key, slot);
-
-		/* figure out how many keys we can insert in here */
-		total_data = data_size[0];
-		for (i = 1; i < nr; i++) {
-			if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0)
-				break;
-			total_data += data_size[i];
-		}
-		nr = i;
-
-		if (old_data < data_end) {
-			btrfs_print_leaf(root, leaf);
-			printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
-			       slot, old_data, data_end);
-			BUG_ON(1);
-		}
-		/*
-		 * item0..itemN ... dataN.offset..dataN.size .. data0.size
-		 */
-		/* first correct the data pointers */
-		for (i = slot; i < nritems; i++) {
-			u32 ioff;
-
-			item = btrfs_item_nr(leaf, i);
-			ioff = btrfs_token_item_offset(leaf, item, &token);
-			btrfs_set_token_item_offset(leaf, item,
-						    ioff - total_data, &token);
-		}
-		/* shift the items */
-		memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
-			      btrfs_item_nr_offset(slot),
-			      (nritems - slot) * sizeof(struct btrfs_item));
-
-		/* shift the data */
-		memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
-			      data_end - total_data, btrfs_leaf_data(leaf) +
-			      data_end, old_data - data_end);
-		data_end = old_data;
-	} else {
-		/*
-		 * this sucks but it has to be done, if we are inserting at
-		 * the end of the leaf only insert 1 of the items, since we
-		 * have no way of knowing whats on the next leaf and we'd have
-		 * to drop our current locks to figure it out
-		 */
-		nr = 1;
-	}
-
-	/* setup the item for the new data */
-	for (i = 0; i < nr; i++) {
-		btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
-		btrfs_set_item_key(leaf, &disk_key, slot + i);
-		item = btrfs_item_nr(leaf, slot + i);
-		btrfs_set_token_item_offset(leaf, item,
-					    data_end - data_size[i], &token);
-		data_end -= data_size[i];
-		btrfs_set_token_item_size(leaf, item, data_size[i], &token);
-	}
-	btrfs_set_header_nritems(leaf, nritems + nr);
-	btrfs_mark_buffer_dirty(leaf);
-
-	ret = 0;
-	if (slot == 0) {
-		btrfs_cpu_key_to_disk(&disk_key, cpu_key);
-		fixup_low_keys(trans, root, path, &disk_key, 1);
-	}
-
-	if (btrfs_leaf_free_space(root, leaf) < 0) {
-		btrfs_print_leaf(root, leaf);
-		BUG();
-	}
-out:
-	if (!ret)
-		ret = nr;
-	return ret;
-}
-
-/*
  * this is a helper for btrfs_insert_empty_items, the main goal here is
  * to save stack depth by doing the bulk of the work in a function
  * that doesn't call btrfs_search_slot
@@ -4705,8 +4605,7 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
  * empty a node.
  */
 static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		    struct btrfs_path *path, int level, int slot,
-		    int tree_mod_log)
+		    struct btrfs_path *path, int level, int slot)
 {
 	struct extent_buffer *parent = path->nodes[level];
 	u32 nritems;
@@ -4714,7 +4613,7 @@ static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 
 	nritems = btrfs_header_nritems(parent);
 	if (slot != nritems - 1) {
-		if (tree_mod_log && level)
+		if (level)
 			tree_mod_log_eb_move(root->fs_info, parent, slot,
 					     slot + 1, nritems - slot - 1);
 		memmove_extent_buffer(parent,
@@ -4722,7 +4621,7 @@ static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 			      btrfs_node_key_ptr_offset(slot + 1),
 			      sizeof(struct btrfs_key_ptr) *
 			      (nritems - slot - 1));
-	} else if (tree_mod_log && level) {
+	} else if (level) {
 		ret = tree_mod_log_insert_key(root->fs_info, parent, slot,
 					      MOD_LOG_KEY_REMOVE);
 		BUG_ON(ret < 0);
@@ -4759,7 +4658,7 @@ static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans,
 				    struct extent_buffer *leaf)
 {
 	WARN_ON(btrfs_header_generation(leaf) != trans->transid);
-	del_ptr(trans, root, path, 1, path->slots[1], 1);
+	del_ptr(trans, root, path, 1, path->slots[1]);
 
 	/*
 	 * btrfs_free_extent is expensive, we want to make sure we
@@ -5073,6 +4972,7 @@ static void tree_move_down(struct btrfs_root *root,
 			   struct btrfs_path *path,
 			   int *level, int root_level)
 {
+	BUG_ON(*level == 0);
 	path->nodes[*level - 1] = read_node_slot(root, path->nodes[*level],
 					path->slots[*level]);
 	path->slots[*level - 1] = 0;
@@ -5089,7 +4989,7 @@ static int tree_move_next_or_upnext(struct btrfs_root *root,
 
 	path->slots[*level]++;
 
-	while (path->slots[*level] == nritems) {
+	while (path->slots[*level] >= nritems) {
 		if (*level == root_level)
 			return -1;
 
@@ -5225,13 +5125,13 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
 	right_path->search_commit_root = 1;
 	right_path->skip_locking = 1;
 
-	spin_lock(&left_root->root_times_lock);
+	spin_lock(&left_root->root_item_lock);
 	left_start_ctransid = btrfs_root_ctransid(&left_root->root_item);
-	spin_unlock(&left_root->root_times_lock);
+	spin_unlock(&left_root->root_item_lock);
 
-	spin_lock(&right_root->root_times_lock);
+	spin_lock(&right_root->root_item_lock);
 	right_start_ctransid = btrfs_root_ctransid(&right_root->root_item);
-	spin_unlock(&right_root->root_times_lock);
+	spin_unlock(&right_root->root_item_lock);
 
 	trans = btrfs_join_transaction(left_root);
 	if (IS_ERR(trans)) {
@@ -5326,15 +5226,15 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
 				goto out;
 			}
 
-			spin_lock(&left_root->root_times_lock);
+			spin_lock(&left_root->root_item_lock);
 			ctransid = btrfs_root_ctransid(&left_root->root_item);
-			spin_unlock(&left_root->root_times_lock);
+			spin_unlock(&left_root->root_item_lock);
 			if (ctransid != left_start_ctransid)
 				left_start_ctransid = 0;
 
-			spin_lock(&right_root->root_times_lock);
+			spin_lock(&right_root->root_item_lock);
 			ctransid = btrfs_root_ctransid(&right_root->root_item);
-			spin_unlock(&right_root->root_times_lock);
+			spin_unlock(&right_root->root_item_lock);
 			if (ctransid != right_start_ctransid)
 				right_start_ctransid = 0;
 
@@ -5433,9 +5333,11 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
 					goto out;
 				advance_right = ADVANCE;
 			} else {
+				WARN_ON(!extent_buffer_uptodate(left_path->nodes[0]));
 				ret = tree_compare_item(left_root, left_path,
 						right_path, tmp_buf);
 				if (ret) {
+					WARN_ON(!extent_buffer_uptodate(left_path->nodes[0]));
 					ret = changed_cb(left_root, right_root,
 						left_path, right_path,
 						&left_key,
@@ -5596,6 +5498,139 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
 	return btrfs_next_old_leaf(root, path, 0);
 }
 
+/* Release the path up to but not including the given level */
+static void btrfs_release_level(struct btrfs_path *path, int level)
+{
+	int i;
+
+	for (i = 0; i < level; i++) {
+		path->slots[i] = 0;
+		if (!path->nodes[i])
+			continue;
+		if (path->locks[i]) {
+			btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]);
+			path->locks[i] = 0;
+		}
+		free_extent_buffer(path->nodes[i]);
+		path->nodes[i] = NULL;
+	}
+}
+
+/*
+ * This function assumes 2 things
+ *
+ * 1) You are using path->keep_locks
+ * 2) You are not inserting items.
+ *
+ * If either of these are not true do not use this function. If you need a next
+ * leaf with either of these not being true then this function can be easily
+ * adapted to do that, but at the moment these are the limitations.
+ */
+int btrfs_next_leaf_write(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root, struct btrfs_path *path,
+			  int del)
+{
+	struct extent_buffer *b;
+	struct btrfs_key key;
+	u32 nritems;
+	int level = 1;
+	int slot;
+	int ret = 1;
+	int write_lock_level = BTRFS_MAX_LEVEL;
+	int ins_len = del ? -1 : 0;
+
+	WARN_ON(!(path->keep_locks || path->really_keep_locks));
+
+	nritems = btrfs_header_nritems(path->nodes[0]);
+	btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
+
+	while (path->nodes[level]) {
+		nritems = btrfs_header_nritems(path->nodes[level]);
+		if (!(path->locks[level] & BTRFS_WRITE_LOCK)) {
+search:
+			btrfs_release_path(path);
+			ret = btrfs_search_slot(trans, root, &key, path,
+						ins_len, 1);
+			if (ret < 0)
+				goto out;
+			level = 1;
+			continue;
+		}
+
+		if (path->slots[level] >= nritems - 1) {
+			level++;
+			continue;
+		}
+
+		btrfs_release_level(path, level);
+		break;
+	}
+
+	if (!path->nodes[level]) {
+		ret = 1;
+		goto out;
+	}
+
+	path->slots[level]++;
+	b = path->nodes[level];
+
+	while (b) {
+		level = btrfs_header_level(b);
+
+		if (!should_cow_block(trans, root, b))
+			goto cow_done;
+
+		btrfs_set_path_blocking(path);
+		ret = btrfs_cow_block(trans, root, b,
+				      path->nodes[level + 1],
+				      path->slots[level + 1], &b);
+		if (ret)
+			goto out;
+cow_done:
+		path->nodes[level] = b;
+		btrfs_clear_path_blocking(path, NULL, 0);
+		if (level != 0) {
+			ret = setup_nodes_for_search(trans, root, path, b,
+						     level, ins_len,
+						     &write_lock_level);
+			if (ret == -EAGAIN)
+				goto search;
+			if (ret)
+				goto out;
+
+			b = path->nodes[level];
+			slot = path->slots[level];
+
+			ret = read_block_for_search(trans, root, path,
+						    &b, level, slot, &key, 0);
+			if (ret == -EAGAIN)
+				goto search;
+			if (ret)
+				goto out;
+			level = btrfs_header_level(b);
+			if (!btrfs_try_tree_write_lock(b)) {
+				btrfs_set_path_blocking(path);
+				btrfs_tree_lock(b);
+				btrfs_clear_path_blocking(path, b,
+							  BTRFS_WRITE_LOCK);
+			}
+			path->locks[level] = BTRFS_WRITE_LOCK;
+			path->nodes[level] = b;
+			path->slots[level] = 0;
+		} else {
+			path->slots[level] = 0;
+			ret = 0;
+			break;
+		}
+	}
+
+out:
+	if (ret)
+		btrfs_release_path(path);
+
+	return ret;
+}
+
 int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 			u64 time_seq)
 {