Commit 7c2fe32a authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Fix add_extent_mapping to check for duplicates across the whole range 



add_extent_mapping was allowing the insertion of overlapping extents.
This never used to happen because it only inserted the extents from disk
and those were never overlapping.

But, with the data=ordered code, the disk and memory representations of the
file are not the same.  add_extent_mapping needs to ensure a new extent
does not overlap before it inserts.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 902b22f3

fs/btrfs/extent_map.c

+7 −0
Original line number Diff line number Diff line
@@ -207,7 +207,14 @@ int add_extent_mapping(struct extent_map_tree *tree, 
	int ret = 0;

	struct extent_map *merge = NULL;

	struct rb_node *rb;

	struct extent_map *exist;



	exist = lookup_extent_mapping(tree, em->start, em->len);

	if (exist) {

		free_extent_map(exist);

		ret = -EEXIST;

		goto out;

	}

	assert_spin_locked(&tree->lock);

	rb = tree_insert(&tree->map, em->start, &em->rb_node);

	if (rb) {

fs/btrfs/inode.c

+17 −4
Original line number Diff line number Diff line
@@ -641,6 +641,7 @@ int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end) 
		if (ret == -ENOENT || ret == -EFBIG)

			ret = 0;

		csum = 0;

		if (printk_ratelimit())

			printk("no csum found for inode %lu start %Lu\n", inode->i_ino,

			       start);

		goto out;
@@ -1653,8 +1654,20 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) 
		btrfs_truncate_page(inode->i_mapping, inode->i_size);



		hole_size = block_end - hole_start;

		while(1) {

			struct btrfs_ordered_extent *ordered;

			btrfs_wait_ordered_range(inode, hole_start, hole_size);



			lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);

			ordered = btrfs_lookup_ordered_extent(inode, hole_start);

			if (ordered) {

				unlock_extent(io_tree, hole_start,

					      block_end - 1, GFP_NOFS);

				btrfs_put_ordered_extent(ordered);

			} else {

				break;

			}

		}



		trans = btrfs_start_transaction(root, 1);

		btrfs_set_trans_block_group(trans, inode);

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