Btrfs: corruption hunt continues

Signed-off-by: Chris Mason <chris.mason@oracle.com>

11 files changed, 187 insertions, 105 deletions

diff --git a/fs/btrfs/bit-radix.c b/fs/btrfs/bit-radix.c
index 43807cc3cce..845422368f4 100644
--- a/fs/btrfs/bit-radix.c
+++ b/fs/btrfs/bit-radix.c
@@ -16,12 +16,14 @@ int set_radix_bit(struct radix_tree_root *radix, unsigned long bit)
 
 	bits = radix_tree_lookup(radix, slot);
 	if (!bits) {
-		bits = kmalloc(BIT_ARRAY_BYTES, GFP_NOIO);
+		bits = kmalloc(BIT_ARRAY_BYTES, GFP_NOFS);
 		if (!bits)
 			return -ENOMEM;
 		memset(bits + 1, 0, BIT_ARRAY_BYTES - sizeof(unsigned long));
 		bits[0] = slot;
+		radix_tree_preload(GFP_NOFS);
 		ret = radix_tree_insert(radix, slot, bits);
+		radix_tree_preload_end();
 		if (ret)
 			return ret;
 	}
@@ -59,7 +61,7 @@ int clear_radix_bit(struct radix_tree_root *radix, unsigned long bit)
 	if (!bits)
 		return 0;
 	clear_bit(bit_slot, bits + 1);
-
+#if 0
 	for (i = 1; i < BIT_ARRAY_BYTES / sizeof(unsigned long); i++) {
 		if (bits[i]) {
 			empty = 0;
@@ -69,8 +71,11 @@ int clear_radix_bit(struct radix_tree_root *radix, unsigned long bit)
 
 	if (empty) {
 		bits = radix_tree_delete(radix, slot);
+		synchronize_rcu();
 		BUG_ON(!bits);
+		kfree(bits);
 	}
+#endif
 	return 0;
 }
 
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b7f3fcb72c6..a0dfa2d6cb9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -51,7 +51,7 @@ static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
 	btrfs_set_header_blocknr(&cow_node->header, cow->b_blocknr);
 	btrfs_set_header_generation(&cow_node->header, trans->transid);
 	*cow_ret = cow;
-	mark_buffer_dirty(cow);
+	btrfs_mark_buffer_dirty(cow);
 	btrfs_inc_ref(trans, root, buf);
 	if (buf == root->node) {
 		root->node = cow;
@@ -62,7 +62,7 @@ static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
 	} else {
 		btrfs_set_node_blockptr(btrfs_buffer_node(parent), parent_slot,
 					cow->b_blocknr);
-		mark_buffer_dirty(parent);
+		btrfs_mark_buffer_dirty(parent);
 		btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1);
 	}
 	btrfs_block_release(root, buf);
@@ -312,11 +312,12 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
 		BUG_ON(!child);
 		root->node = child;
 		path->nodes[level] = NULL;
+		clean_tree_block(trans, root, mid_buf);
+		wait_on_buffer(mid_buf);
 		/* once for the path */
 		btrfs_block_release(root, mid_buf);
 		/* once for the root ptr */
 		btrfs_block_release(root, mid_buf);
-		clean_tree_block(trans, root, mid_buf);
 		return btrfs_free_extent(trans, root, blocknr, 1, 1);
 	}
 	parent = btrfs_buffer_node(parent_buf);
@@ -351,8 +352,9 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
 			ret = wret;
 		if (btrfs_header_nritems(&right->header) == 0) {
 			u64 blocknr = right_buf->b_blocknr;
-			btrfs_block_release(root, right_buf);
 			clean_tree_block(trans, root, right_buf);
+			wait_on_buffer(right_buf);
+			btrfs_block_release(root, right_buf);
 			right_buf = NULL;
 			right = NULL;
 			wret = del_ptr(trans, root, path, level + 1, pslot +
@@ -363,10 +365,11 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
 			if (wret)
 				ret = wret;
 		} else {
-			memcpy(&parent->ptrs[pslot + 1].key,
-				&right->ptrs[0].key,
-				sizeof(struct btrfs_disk_key));
-			mark_buffer_dirty(parent_buf);
+			btrfs_memcpy(root, parent,
+				     &parent->ptrs[pslot + 1].key,
+				     &right->ptrs[0].key,
+				     sizeof(struct btrfs_disk_key));
+			btrfs_mark_buffer_dirty(parent_buf);
 		}
 	}
 	if (btrfs_header_nritems(&mid->header) == 1) {
@@ -388,8 +391,9 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (btrfs_header_nritems(&mid->header) == 0) {
 		/* we've managed to empty the middle node, drop it */
 		u64 blocknr = mid_buf->b_blocknr;
-		btrfs_block_release(root, mid_buf);
 		clean_tree_block(trans, root, mid_buf);
+		wait_on_buffer(mid_buf);
+		btrfs_block_release(root, mid_buf);
 		mid_buf = NULL;
 		mid = NULL;
 		wret = del_ptr(trans, root, path, level + 1, pslot);
@@ -400,9 +404,10 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
 			ret = wret;
 	} else {
 		/* update the parent key to reflect our changes */
-		memcpy(&parent->ptrs[pslot].key, &mid->ptrs[0].key,
-		       sizeof(struct btrfs_disk_key));
-		mark_buffer_dirty(parent_buf);
+		btrfs_memcpy(root, parent,
+			     &parent->ptrs[pslot].key, &mid->ptrs[0].key,
+			     sizeof(struct btrfs_disk_key));
+		btrfs_mark_buffer_dirty(parent_buf);
 	}
 
 	/* update the path */
@@ -544,8 +549,8 @@ static int fixup_low_keys(struct btrfs_trans_handle *trans, struct btrfs_root
 		if (!path->nodes[i])
 			break;
 		t = btrfs_buffer_node(path->nodes[i]);
-		memcpy(&t->ptrs[tslot].key, key, sizeof(*key));
-		mark_buffer_dirty(path->nodes[i]);
+		btrfs_memcpy(root, t, &t->ptrs[tslot].key, key, sizeof(*key));
+		btrfs_mark_buffer_dirty(path->nodes[i]);
 		if (tslot != 0)
 			break;
 	}
@@ -580,17 +585,17 @@ static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (src_nritems < push_items)
 		push_items = src_nritems;
 
-	memcpy(dst->ptrs + dst_nritems, src->ptrs,
-		push_items * sizeof(struct btrfs_key_ptr));
+	btrfs_memcpy(root, dst, dst->ptrs + dst_nritems, src->ptrs,
+		     push_items * sizeof(struct btrfs_key_ptr));
 	if (push_items < src_nritems) {
-		memmove(src->ptrs, src->ptrs + push_items,
+		btrfs_memmove(root, src, src->ptrs, src->ptrs + push_items,
 			(src_nritems - push_items) *
 			sizeof(struct btrfs_key_ptr));
 	}
 	btrfs_set_header_nritems(&src->header, src_nritems - push_items);
 	btrfs_set_header_nritems(&dst->header, dst_nritems + push_items);
-	mark_buffer_dirty(src_buf);
-	mark_buffer_dirty(dst_buf);
+	btrfs_mark_buffer_dirty(src_buf);
+	btrfs_mark_buffer_dirty(dst_buf);
 	return ret;
 }
 
@@ -629,16 +634,18 @@ static int balance_node_right(struct btrfs_trans_handle *trans, struct
 	if (max_push < push_items)
 		push_items = max_push;
 
-	memmove(dst->ptrs + push_items, dst->ptrs,
-		dst_nritems * sizeof(struct btrfs_key_ptr));
-	memcpy(dst->ptrs, src->ptrs + src_nritems - push_items,
-		push_items * sizeof(struct btrfs_key_ptr));
+	btrfs_memmove(root, dst, dst->ptrs + push_items, dst->ptrs,
+		      dst_nritems * sizeof(struct btrfs_key_ptr));
+
+	btrfs_memcpy(root, dst, dst->ptrs,
+		     src->ptrs + src_nritems - push_items,
+		     push_items * sizeof(struct btrfs_key_ptr));
 
 	btrfs_set_header_nritems(&src->header, src_nritems - push_items);
 	btrfs_set_header_nritems(&dst->header, dst_nritems + push_items);
 
-	mark_buffer_dirty(src_buf);
-	mark_buffer_dirty(dst_buf);
+	btrfs_mark_buffer_dirty(src_buf);
+	btrfs_mark_buffer_dirty(dst_buf);
 	return ret;
 }
 
@@ -674,10 +681,11 @@ static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root
 		lower_key = &((struct btrfs_leaf *)lower)->items[0].key;
 	else
 		lower_key = &lower->ptrs[0].key;
-	memcpy(&c->ptrs[0].key, lower_key, sizeof(struct btrfs_disk_key));
+	btrfs_memcpy(root, c, &c->ptrs[0].key, lower_key,
+		     sizeof(struct btrfs_disk_key));
 	btrfs_set_node_blockptr(c, 0, path->nodes[level - 1]->b_blocknr);
 
-	mark_buffer_dirty(t);
+	btrfs_mark_buffer_dirty(t);
 
 	/* the super has an extra ref to root->node */
 	btrfs_block_release(root, root->node);
@@ -712,13 +720,15 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
 		BUG();
 	if (slot != nritems) {
-		memmove(lower->ptrs + slot + 1, lower->ptrs + slot,
-			(nritems - slot) * sizeof(struct btrfs_key_ptr));
+		btrfs_memmove(root, lower, lower->ptrs + slot + 1,
+			      lower->ptrs + slot,
+			      (nritems - slot) * sizeof(struct btrfs_key_ptr));
 	}
-	memcpy(&lower->ptrs[slot].key, key, sizeof(struct btrfs_disk_key));
+	btrfs_memcpy(root, lower, &lower->ptrs[slot].key,
+		     key, sizeof(struct btrfs_disk_key));
 	btrfs_set_node_blockptr(lower, slot, blocknr);
 	btrfs_set_header_nritems(&lower->header, nritems + 1);
-	mark_buffer_dirty(path->nodes[level]);
+	btrfs_mark_buffer_dirty(path->nodes[level]);
 	return 0;
 }
 
@@ -761,14 +771,14 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
 	btrfs_set_header_parentid(&split->header,
 	      btrfs_header_parentid(btrfs_buffer_header(root->node)));
 	mid = (c_nritems + 1) / 2;
-	memcpy(split->ptrs, c->ptrs + mid,
-		(c_nritems - mid) * sizeof(struct btrfs_key_ptr));
+	btrfs_memcpy(root, split, split->ptrs, c->ptrs + mid,
+		     (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
 	btrfs_set_header_nritems(&split->header, c_nritems - mid);
 	btrfs_set_header_nritems(&c->header, mid);
 	ret = 0;
 
-	mark_buffer_dirty(t);
-	mark_buffer_dirty(split_buffer);
+	btrfs_mark_buffer_dirty(t);
+	btrfs_mark_buffer_dirty(split_buffer);
 	wret = insert_ptr(trans, root, path, &split->ptrs[0].key,
 			  split_buffer->b_blocknr, path->slots[level + 1] + 1,
 			  level + 1);
@@ -875,17 +885,22 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 	push_space = btrfs_item_end(left->items + left_nritems - push_items);
 	push_space -= leaf_data_end(root, left);
 	/* make room in the right data area */
-	memmove(btrfs_leaf_data(right) + leaf_data_end(root, right) -
-		push_space, btrfs_leaf_data(right) + leaf_data_end(root, right),
-		BTRFS_LEAF_DATA_SIZE(root) - leaf_data_end(root, right));
+	btrfs_memmove(root, right, btrfs_leaf_data(right) +
+		      leaf_data_end(root, right) - push_space,
+		      btrfs_leaf_data(right) +
+		      leaf_data_end(root, right), BTRFS_LEAF_DATA_SIZE(root) -
+		      leaf_data_end(root, right));
 	/* copy from the left data area */
-	memcpy(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - push_space,
-		btrfs_leaf_data(left) + leaf_data_end(root, left), push_space);
-	memmove(right->items + push_items, right->items,
+	btrfs_memcpy(root, right, btrfs_leaf_data(right) +
+		     BTRFS_LEAF_DATA_SIZE(root) - push_space,
+		     btrfs_leaf_data(left) + leaf_data_end(root, left),
+		     push_space);
+	btrfs_memmove(root, right, right->items + push_items, right->items,
 		right_nritems * sizeof(struct btrfs_item));
 	/* copy the items from left to right */
-	memcpy(right->items, left->items + left_nritems - push_items,
-		push_items * sizeof(struct btrfs_item));
+	btrfs_memcpy(root, right, right->items, left->items +
+		     left_nritems - push_items,
+		     push_items * sizeof(struct btrfs_item));
 
 	/* update the item pointers */
 	right_nritems += push_items;
@@ -899,11 +914,11 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 	left_nritems -= push_items;
 	btrfs_set_header_nritems(&left->header, left_nritems);
 
-	mark_buffer_dirty(left_buf);
-	mark_buffer_dirty(right_buf);
-	memcpy(&upper_node->ptrs[slot + 1].key,
+	btrfs_mark_buffer_dirty(left_buf);
+	btrfs_mark_buffer_dirty(right_buf);
+	btrfs_memcpy(root, upper_node, &upper_node->ptrs[slot + 1].key,
 		&right->items[0].key, sizeof(struct btrfs_disk_key));
-	mark_buffer_dirty(upper);
+	btrfs_mark_buffer_dirty(upper);
 
 	/* then fixup the leaf pointer in the path */
 	if (path->slots[0] >= left_nritems) {
@@ -977,14 +992,16 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 		return 1;
 	}
 	/* push data from right to left */
-	memcpy(left->items + btrfs_header_nritems(&left->header),
-		right->items, push_items * sizeof(struct btrfs_item));
+	btrfs_memcpy(root, left, left->items +
+		     btrfs_header_nritems(&left->header),
+		     right->items, push_items * sizeof(struct btrfs_item));
 	push_space = BTRFS_LEAF_DATA_SIZE(root) -
 		     btrfs_item_offset(right->items + push_items -1);
-	memcpy(btrfs_leaf_data(left) + leaf_data_end(root, left) - push_space,
-		btrfs_leaf_data(right) +
-		btrfs_item_offset(right->items + push_items - 1),
-		push_space);
+	btrfs_memcpy(root, left, btrfs_leaf_data(left) +
+		     leaf_data_end(root, left) - push_space,
+		     btrfs_leaf_data(right) +
+		     btrfs_item_offset(right->items + push_items - 1),
+		     push_space);
 	old_left_nritems = btrfs_header_nritems(&left->header);
 	BUG_ON(old_left_nritems < 0);
 
@@ -1000,10 +1017,11 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 	/* fixup right node */
 	push_space = btrfs_item_offset(right->items + push_items - 1) -
 		     leaf_data_end(root, right);
-	memmove(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
-		push_space, btrfs_leaf_data(right) +
-		leaf_data_end(root, right), push_space);
-	memmove(right->items, right->items + push_items,
+	btrfs_memmove(root, right, btrfs_leaf_data(right) +
+		      BTRFS_LEAF_DATA_SIZE(root) - push_space,
+		      btrfs_leaf_data(right) +
+		      leaf_data_end(root, right), push_space);
+	btrfs_memmove(root, right, right->items, right->items + push_items,
 		(btrfs_header_nritems(&right->header) - push_items) *
 		sizeof(struct btrfs_item));
 	btrfs_set_header_nritems(&right->header,
@@ -1017,8 +1035,8 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 		push_space = btrfs_item_offset(right->items + i);
 	}
 
-	mark_buffer_dirty(t);
-	mark_buffer_dirty(right_buf);
+	btrfs_mark_buffer_dirty(t);
+	btrfs_mark_buffer_dirty(right_buf);
 
 	wret = fixup_low_keys(trans, root, path, &right->items[0].key, 1);
 	if (wret)
@@ -1110,11 +1128,12 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
 	      btrfs_header_parentid(btrfs_buffer_header(root->node)));
 	data_copy_size = btrfs_item_end(l->items + mid) -
 			 leaf_data_end(root, l);
-	memcpy(right->items, l->items + mid,
-	       (nritems - mid) * sizeof(struct btrfs_item));
-	memcpy(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
-		data_copy_size, btrfs_leaf_data(l) +
-		leaf_data_end(root, l), data_copy_size);
+	btrfs_memcpy(root, right, right->items, l->items + mid,
+		     (nritems - mid) * sizeof(struct btrfs_item));
+	btrfs_memcpy(root, right,
+		     btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
+		     data_copy_size, btrfs_leaf_data(l) +
+		     leaf_data_end(root, l), data_copy_size);
 	rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
 		      btrfs_item_end(l->items + mid);
 
@@ -1129,8 +1148,8 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
 			  right_buffer->b_blocknr, path->slots[1] + 1, 1);
 	if (wret)
 		ret = wret;
-	mark_buffer_dirty(right_buffer);
-	mark_buffer_dirty(l_buf);
+	btrfs_mark_buffer_dirty(right_buffer);
+	btrfs_mark_buffer_dirty(l_buf);
 	BUG_ON(path->slots[0] != slot);
 	if (mid <= slot) {
 		btrfs_block_release(root, path->nodes[0]);
@@ -1200,22 +1219,23 @@ int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root
 		}
 
 		/* shift the items */
-		memmove(leaf->items + slot + 1, leaf->items + slot,
-		        (nritems - slot) * sizeof(struct btrfs_item));
+		btrfs_memmove(root, leaf, leaf->items + slot + 1,
+			      leaf->items + slot,
+			      (nritems - slot) * sizeof(struct btrfs_item));
 
 		/* shift the data */
-		memmove(btrfs_leaf_data(leaf) + data_end - data_size,
-			btrfs_leaf_data(leaf) +
-		        data_end, old_data - data_end);
+		btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) +
+			      data_end - data_size, btrfs_leaf_data(leaf) +
+			      data_end, old_data - data_end);
 		data_end = old_data;
 	}
 	/* setup the item for the new data */
-	memcpy(&leaf->items[slot].key, &disk_key,
-		sizeof(struct btrfs_disk_key));
+	btrfs_memcpy(root, leaf, &leaf->items[slot].key, &disk_key,
+		     sizeof(struct btrfs_disk_key));
 	btrfs_set_item_offset(leaf->items + slot, data_end - data_size);
 	btrfs_set_item_size(leaf->items + slot, data_size);
 	btrfs_set_header_nritems(&leaf->header, nritems + 1);
-	mark_buffer_dirty(leaf_buf);
+	btrfs_mark_buffer_dirty(leaf_buf);
 
 	ret = 0;
 	if (slot == 0)
@@ -1245,8 +1265,9 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (!ret) {
 		ptr = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
 				     path.slots[0], u8);
-		memcpy(ptr, data, data_size);
-		mark_buffer_dirty(path.nodes[0]);
+		btrfs_memcpy(root, path.nodes[0]->b_data,
+			     ptr, data, data_size);
+		btrfs_mark_buffer_dirty(path.nodes[0]);
 	}
 	btrfs_release_path(root, &path);
 	return ret;
@@ -1271,8 +1292,10 @@ static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	node = btrfs_buffer_node(parent);
 	nritems = btrfs_header_nritems(&node->header);
 	if (slot != nritems -1) {
-		memmove(node->ptrs + slot, node->ptrs + slot + 1,
-			sizeof(struct btrfs_key_ptr) * (nritems - slot - 1));
+		btrfs_memmove(root, node, node->ptrs + slot,
+			      node->ptrs + slot + 1,
+			      sizeof(struct btrfs_key_ptr) *
+			      (nritems - slot - 1));
 	}
 	nritems--;
 	btrfs_set_header_nritems(&node->header, nritems);
@@ -1287,7 +1310,7 @@ static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		if (wret)
 			ret = wret;
 	}
-	mark_buffer_dirty(parent);
+	btrfs_mark_buffer_dirty(parent);
 	return ret;
 }
 
@@ -1317,16 +1340,18 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	if (slot != nritems - 1) {
 		int i;
 		int data_end = leaf_data_end(root, leaf);
-		memmove(btrfs_leaf_data(leaf) + data_end + dsize,
-			btrfs_leaf_data(leaf) + data_end,
-			doff - data_end);
+		btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) +
+			      data_end + dsize,
+			      btrfs_leaf_data(leaf) + data_end,
+			      doff - data_end);
 		for (i = slot + 1; i < nritems; i++) {
 			u32 ioff = btrfs_item_offset(leaf->items + i);
 			btrfs_set_item_offset(leaf->items + i, ioff + dsize);
 		}
-		memmove(leaf->items + slot, leaf->items + slot + 1,
-			sizeof(struct btrfs_item) *
-			(nritems - slot - 1));
+		btrfs_memmove(root, leaf, leaf->items + slot,
+			      leaf->items + slot + 1,
+			      sizeof(struct btrfs_item) *
+			      (nritems - slot - 1));
 	}
 	btrfs_set_header_nritems(&leaf->header, nritems - 1);
 	nritems--;
@@ -1336,6 +1361,7 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 			btrfs_set_header_level(&leaf->header, 0);
 		} else {
 			clean_tree_block(trans, root, leaf_buf);
+			wait_on_buffer(leaf_buf);
 			wret = del_ptr(trans, root, path, 1, path->slots[1]);
 			if (wret)
 				ret = wret;
@@ -1373,6 +1399,7 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 			if (btrfs_header_nritems(&leaf->header) == 0) {
 				u64 blocknr = leaf_buf->b_blocknr;
 				clean_tree_block(trans, root, leaf_buf);
+				wait_on_buffer(leaf_buf);
 				wret = del_ptr(trans, root, path, 1, slot);
 				if (wret)
 					ret = wret;
@@ -1382,11 +1409,11 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 				if (wret)
 					ret = wret;
 			} else {
-				mark_buffer_dirty(leaf_buf);
+				btrfs_mark_buffer_dirty(leaf_buf);
 				btrfs_block_release(root, leaf_buf);
 			}
 		} else {
-			mark_buffer_dirty(leaf_buf);
+			btrfs_mark_buffer_dirty(leaf_buf);
 		}
 	}
 	return ret;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index df1a025a771..9ec0d65ebe9 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2,6 +2,7 @@
 #define __BTRFS__
 
 #include <linux/fs.h>
+#include <linux/buffer_head.h>
 #include "bit-radix.h"
 
 struct btrfs_trans_handle;
@@ -834,6 +835,37 @@ static inline struct btrfs_root *btrfs_sb(struct super_block *sb)
 	return sb->s_fs_info;
 }
 
+static inline void btrfs_check_bounds(void *vptr, size_t len,
+				     void *vcontainer, size_t container_len)
+{
+	char *ptr = vptr;
+	char *container = vcontainer;
+	WARN_ON(ptr < container);
+	WARN_ON(ptr + len > container + container_len);
+}
+
+static inline void btrfs_memcpy(struct btrfs_root *root,
+				void *dst_block,
+				void *dst, const void *src, size_t nr)
+{
+	btrfs_check_bounds(dst, nr, dst_block, root->fs_info->sb->s_blocksize);
+	memcpy(dst, src, nr);
+}
+
+static inline void btrfs_memmove(struct btrfs_root *root,
+				void *dst_block,
+				void *dst, void *src, size_t nr)
+{
+	btrfs_check_bounds(dst, nr, dst_block, root->fs_info->sb->s_blocksize);
+	memmove(dst, src, nr);
+}
+
+static inline void btrfs_mark_buffer_dirty(struct buffer_head *bh)
+{
+	WARN_ON(!atomic_read(&bh->b_count));
+	mark_buffer_dirty(bh);
+}
+
 /* helper function to cast into the data area of the leaf. */
 #define btrfs_item_ptr(leaf, slot, type) \
 	((type *)(btrfs_leaf_data(leaf) + \
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 18d3e168ad0..f55c89472ac 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -34,10 +34,8 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	btrfs_set_dir_flags(dir_item, 0);
 	btrfs_set_dir_name_len(dir_item, name_len);
 	name_ptr = (char *)(dir_item + 1);
-	memcpy(name_ptr, name, name_len);
-	if (name_ptr + name_len > path.nodes[0]->b_data + 4096)
-		WARN_ON(1);
-	mark_buffer_dirty(path.nodes[0]);
+	btrfs_memcpy(root, path.nodes[0]->b_data, name_ptr, name, name_len);
+	btrfs_mark_buffer_dirty(path.nodes[0]);
 out:
 	btrfs_release_path(root, &path);
 	return ret;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 6c010463b9d..bb133104e2e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -8,6 +8,17 @@
 #include "disk-io.h"
 #include "transaction.h"
 
+#define PATTERN 0xDEADBEEFUL
+static inline void check_pattern(struct buffer_head *buf)
+{
+	if (buf->b_private != (void *)PATTERN)
+		WARN_ON(1);
+}
+
+static inline void set_pattern(struct buffer_head *buf)
+{
+	buf->b_private = (void *)PATTERN;
+}
 
 static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
 {
@@ -51,8 +62,10 @@ struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
 	} while (bh != head);
 out_unlock:
 	unlock_page(page);
-	if (ret)
+	if (ret) {
 		touch_buffer(ret);
+		check_pattern(ret);
+	}
 	page_cache_release(page);
 	return ret;
 }
@@ -82,6 +95,7 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
 			bh->b_bdev = root->fs_info->sb->s_bdev;
 			bh->b_blocknr = first_block;
 			set_buffer_mapped(bh);
+			set_pattern(bh);
 		}
 		if (bh->b_blocknr == blocknr) {
 			ret = bh;
@@ -225,6 +239,7 @@ struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
 		if (!buffer_uptodate(bh))
 			goto fail;
 		csum_tree_block(root, bh, 1);
+		set_pattern(bh);
 	} else {
 		unlock_buffer(bh);
 	}
@@ -240,6 +255,7 @@ fail:
 int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		     struct buffer_head *buf)
 {
+	WARN_ON(atomic_read(&buf->b_count) == 0);
 	mark_buffer_dirty(buf);
 	return 0;
 }
@@ -247,6 +263,7 @@ int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		     struct buffer_head *buf)
 {
+	WARN_ON(atomic_read(&buf->b_count) == 0);
 	clear_buffer_dirty(buf);
 	return 0;
 }
@@ -431,6 +448,7 @@ int close_ctree(struct btrfs_root *root)
 
 void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)
 {
+	check_pattern(buf);
 	brelse(buf);
 }
 
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b2ae8e768b6..c4194dab7a3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -39,7 +39,7 @@ static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
 	item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
 	refs = btrfs_extent_refs(item);
 	btrfs_set_extent_refs(item, refs + 1);
-	mark_buffer_dirty(path.nodes[0]);
+	btrfs_mark_buffer_dirty(path.nodes[0]);
 
 	btrfs_release_path(root->fs_info->extent_root, &path);
 	finish_current_insert(trans, root->fs_info->extent_root);
@@ -177,10 +177,10 @@ static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending)
 			header = btrfs_buffer_header(bh);
 			if (btrfs_header_generation(header) ==
 			    root->fs_info->running_transaction->transid) {
-				brelse(bh);
+				btrfs_block_release(root, bh);
 				return 0;
 			}
-			brelse(bh);
+			btrfs_block_release(root, bh);
 		}
 		err = set_radix_bit(&root->fs_info->pinned_radix, blocknr);
 	} else {
@@ -224,7 +224,7 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
 	BUG_ON(ei->refs == 0);
 	refs = btrfs_extent_refs(ei) - 1;
 	btrfs_set_extent_refs(ei, refs);
-	mark_buffer_dirty(path.nodes[0]);
+	btrfs_mark_buffer_dirty(path.nodes[0]);
 	if (refs == 0) {
 		u64 super_blocks_used;
 
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 2d2c23ca7cb..c3992b7b0c6 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -34,7 +34,7 @@ int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
 	btrfs_set_file_extent_offset(item, 0);
 	btrfs_set_file_extent_num_blocks(item, ins.offset);
 	btrfs_set_file_extent_generation(item, trans->transid);
-	mark_buffer_dirty(path.nodes[0]);
+	btrfs_mark_buffer_dirty(path.nodes[0]);
 	*result = ins.objectid;
 	btrfs_release_path(root, &path);
 	return 0;
@@ -81,7 +81,7 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
 			      struct btrfs_csum_item);
 	ret = 0;
 	ret = btrfs_csum_data(root, data, len, item->csum);
-	mark_buffer_dirty(path.nodes[0]);
+	btrfs_mark_buffer_dirty(path.nodes[0]);
 fail:
 	btrfs_release_path(root, &path);
 	return ret;
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index 1b2c5e04350..fa4adb81b14 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -109,7 +109,7 @@ int btrfs_insert_inode_map(struct btrfs_trans_handle *trans,
 	inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
 				    path.slots[0], struct btrfs_inode_map_item);
 	btrfs_cpu_key_to_disk(&inode_item->key, location);
-	mark_buffer_dirty(path.nodes[0]);
+	btrfs_mark_buffer_dirty(path.nodes[0]);
 out:
 	btrfs_release_path(inode_root, &path);
 	return ret;
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index a821b5d1e23..f37dab87de1 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -45,6 +45,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
 	struct btrfs_leaf *l;
 	int ret;
 	int slot;
+	struct btrfs_root_item *update_item;
 
 	btrfs_init_path(&path);
 	ret = btrfs_search_slot(trans, root, key, &path, 0, 1);
@@ -53,9 +54,9 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
 	BUG_ON(ret != 0);
 	l = btrfs_buffer_leaf(path.nodes[0]);
 	slot = path.slots[0];
-	memcpy(btrfs_item_ptr(l, slot, struct btrfs_root_item), item,
-		sizeof(*item));
-	mark_buffer_dirty(path.nodes[0]);
+	update_item = btrfs_item_ptr(l, slot, struct btrfs_root_item);
+	btrfs_memcpy(root, l, update_item, item, sizeof(*item));
+	btrfs_mark_buffer_dirty(path.nodes[0]);
 out:
 	btrfs_release_path(root, &path);
 	return ret;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index ab5419eea93..894a70bf26d 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -557,7 +557,7 @@ static int btrfs_update_inode(struct btrfs_trans_handle *trans,
 				  struct btrfs_inode_item);
 
 	fill_inode_item(inode_item, inode);
-	mark_buffer_dirty(path.nodes[0]);
+	btrfs_mark_buffer_dirty(path.nodes[0]);
 failed:
 	btrfs_release_path(root, &path);
 	return 0;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index a146463c504..84c4e278ce2 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -66,6 +66,7 @@ int btrfs_end_transaction(struct btrfs_trans_handle *trans,
 	cur_trans->num_writers--;
 	put_transaction(cur_trans);
 	mutex_unlock(&root->fs_info->trans_mutex);
+	memset(trans, 0, sizeof(*trans));
 	kfree(trans);
 	return 0;
 }