Commit f345dbdf authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: tests: add a test for btrfs_add_extent_mapping 



This helper is different from the normal add_extent_mapping in that it
will stuff an em into a gap that exists between overlapping em's in the
tree.  It appeared there was a bug so I wrote a self test to validate it
did the correct thing when it worked with two side by side ems.
Thankfully it is correct, but more testing is better.

Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 89c37604

fs/btrfs/tests/extent-map-tests.c

+56 −0
Original line number Diff line number Diff line
@@ -655,6 +655,59 @@ static int test_case_5(void) 
	return ret;

}



/*

 * Test the btrfs_add_extent_mapping helper which will attempt to create an em

 * for areas between two existing ems.  Validate it doesn't do this when there

 * are two unmerged em's side by side.

 */

static int test_case_6(struct btrfs_fs_info *fs_info, struct extent_map_tree *em_tree)

{

	struct extent_map *em = NULL;

	int ret;



	ret = add_compressed_extent(em_tree, 0, SZ_4K, 0);

	if (ret)

		goto out;



	ret = add_compressed_extent(em_tree, SZ_4K, SZ_4K, 0);

	if (ret)

		goto out;



	em = alloc_extent_map();

	if (!em) {

		test_std_err(TEST_ALLOC_EXTENT_MAP);

		return -ENOMEM;

	}



	em->start = SZ_4K;

	em->len = SZ_4K;

	em->block_start = SZ_16K;

	em->block_len = SZ_16K;

	write_lock(&em_tree->lock);

	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, 0, SZ_8K);

	write_unlock(&em_tree->lock);



	if (ret != 0) {

		test_err("got an error when adding our em: %d", ret);

		goto out;

	}



	ret = -EINVAL;

	if (em->start != 0) {

		test_err("unexpected em->start at %llu, wanted 0", em->start);

		goto out;

	}

	if (em->len != SZ_4K) {

		test_err("unexpected em->len %llu, expected 4K", em->len);

		goto out;

	}

	ret = 0;

out:

	free_extent_map(em);

	free_extent_map_tree(em_tree);

	return ret;

}



struct rmap_test_vector {

	u64 raid_type;

	u64 physical_start;
@@ -835,6 +888,9 @@ int btrfs_test_extent_map(void) 
	if (ret)

		goto out;

	ret = test_case_5();

	if (ret)

		goto out;

	ret = test_case_6(fs_info, em_tree);

	if (ret)

		goto out;