Commit 92e1229b authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: tests: test invalid splitting when skipping pinned drop extent_map 



This reproduces the bug fixed by "btrfs: fix incorrect splitting in
btrfs_drop_extent_map_range", we were improperly calculating the range
for the split extent.  Add a test that exercises this scenario and
validates that we get the correct resulting extent_maps in our tree.

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 f345dbdf

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

+138 −0
Original line number Diff line number Diff line
@@ -708,6 +708,141 @@ static int test_case_6(struct btrfs_fs_info *fs_info, struct extent_map_tree *em 
	return ret;

}



/*

 * Regression test for btrfs_drop_extent_map_range.  Calling with skip_pinned ==

 * true would mess up the start/end calculations and subsequent splits would be

 * incorrect.

 */

static int test_case_7(void)

{

	struct extent_map_tree *em_tree;

	struct extent_map *em;

	struct inode *inode;

	int ret;



	test_msg("Running btrfs_drop_extent_cache with pinned");



	inode = btrfs_new_test_inode();

	if (!inode) {

		test_std_err(TEST_ALLOC_INODE);

		return -ENOMEM;

	}



	em_tree = &BTRFS_I(inode)->extent_tree;



	em = alloc_extent_map();

	if (!em) {

		test_std_err(TEST_ALLOC_EXTENT_MAP);

		ret = -ENOMEM;

		goto out;

	}



	/* [0, 16K), pinned */

	em->start = 0;

	em->len = SZ_16K;

	em->block_start = 0;

	em->block_len = SZ_4K;

	set_bit(EXTENT_FLAG_PINNED, &em->flags);

	write_lock(&em_tree->lock);

	ret = add_extent_mapping(em_tree, em, 0);

	write_unlock(&em_tree->lock);

	if (ret < 0) {

		test_err("couldn't add extent map");

		goto out;

	}

	free_extent_map(em);



	em = alloc_extent_map();

	if (!em) {

		test_std_err(TEST_ALLOC_EXTENT_MAP);

		ret = -ENOMEM;

		goto out;

	}



	/* [32K, 48K), not pinned */

	em->start = SZ_32K;

	em->len = SZ_16K;

	em->block_start = SZ_32K;

	em->block_len = SZ_16K;

	write_lock(&em_tree->lock);

	ret = add_extent_mapping(em_tree, em, 0);

	write_unlock(&em_tree->lock);

	if (ret < 0) {

		test_err("couldn't add extent map");

		goto out;

	}

	free_extent_map(em);



	/*

	 * Drop [0, 36K) This should skip the [0, 4K) extent and then split the

	 * [32K, 48K) extent.

	 */

	btrfs_drop_extent_map_range(BTRFS_I(inode), 0, (36 * SZ_1K) - 1, true);



	/* Make sure our extent maps look sane. */

	ret = -EINVAL;



	em = lookup_extent_mapping(em_tree, 0, SZ_16K);

	if (!em) {

		test_err("didn't find an em at 0 as expected");

		goto out;

	}



	if (em->start != 0) {

		test_err("em->start is %llu, expected 0", em->start);

		goto out;

	}



	if (em->len != SZ_16K) {

		test_err("em->len is %llu, expected 16K", em->len);

		goto out;

	}



	free_extent_map(em);



	read_lock(&em_tree->lock);

	em = lookup_extent_mapping(em_tree, SZ_16K, SZ_16K);

	read_unlock(&em_tree->lock);

	if (em) {

		test_err("found an em when we weren't expecting one");

		goto out;

	}



	read_lock(&em_tree->lock);

	em = lookup_extent_mapping(em_tree, SZ_32K, SZ_16K);

	read_unlock(&em_tree->lock);

	if (!em) {

		test_err("didn't find an em at 32K as expected");

		goto out;

	}



	if (em->start != (36 * SZ_1K)) {

		test_err("em->start is %llu, expected 36K", em->start);

		goto out;

	}



	if (em->len != (12 * SZ_1K)) {

		test_err("em->len is %llu, expected 12K", em->len);

		goto out;

	}



	free_extent_map(em);



	read_lock(&em_tree->lock);

	em = lookup_extent_mapping(em_tree, 48 * SZ_1K, (u64)-1);

	read_unlock(&em_tree->lock);

	if (em) {

		test_err("found an unexpected em above 48K");

		goto out;

	}



	ret = 0;

out:

	free_extent_map(em);

	iput(inode);

	return ret;

}



struct rmap_test_vector {

	u64 raid_type;

	u64 physical_start;
@@ -891,6 +1026,9 @@ int btrfs_test_extent_map(void) 
	if (ret)

		goto out;

	ret = test_case_6(fs_info, em_tree);

	if (ret)

		goto out;

	ret = test_case_7();

	if (ret)

		goto out;