fs/btrfs/tests/free-space-tree-tests.c

Source file repositories/reference/linux-study-clean/fs/btrfs/tests/free-space-tree-tests.c

File Facts

System
Linux kernel
Corpus path
fs/btrfs/tests/free-space-tree-tests.c
Extension
.c
Size
14975 bytes
Lines
587
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct free_space_extent {
	u64 start;
	u64 length;
};

static int __check_free_space_extents(struct btrfs_trans_handle *trans,
				      struct btrfs_fs_info *fs_info,
				      struct btrfs_block_group *cache,
				      struct btrfs_path *path,
				      const struct free_space_extent * const extents,
				      unsigned int num_extents)
{
	struct btrfs_free_space_info *info;
	struct btrfs_key key;
	int prev_bit = 0, bit;
	u64 extent_start = 0, offset, end;
	u32 flags, extent_count;
	unsigned int i;
	int ret;

	info = btrfs_search_free_space_info(trans, cache, path, 0);
	if (IS_ERR(info)) {
		test_err("could not find free space info");
		ret = PTR_ERR(info);
		goto out;
	}
	flags = btrfs_free_space_flags(path->nodes[0], info);
	extent_count = btrfs_free_space_extent_count(path->nodes[0], info);

	if (extent_count != num_extents) {
		test_err("extent count is wrong");
		ret = -EINVAL;
		goto out;
	}
	if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) {
		if (path->slots[0] != 0)
			goto invalid;
		end = btrfs_block_group_end(cache);
		i = 0;
		while (++path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
			btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
			if (key.type != BTRFS_FREE_SPACE_BITMAP_KEY)
				goto invalid;
			offset = key.objectid;
			while (offset < key.objectid + key.offset) {
				bit = btrfs_free_space_test_bit(cache, path, offset);
				if (prev_bit == 0 && bit == 1) {
					extent_start = offset;
				} else if (prev_bit == 1 && bit == 0) {
					if (i >= num_extents ||
					    extent_start != extents[i].start ||
					    offset - extent_start != extents[i].length)
						goto invalid;
					i++;
				}
				prev_bit = bit;
				offset += fs_info->sectorsize;
			}
		}
		if (prev_bit == 1) {
			if (i >= num_extents ||
			    extent_start != extents[i].start ||
			    end - extent_start != extents[i].length)
				goto invalid;
			i++;
		}
		if (i != num_extents)
			goto invalid;
	} else {
		if (btrfs_header_nritems(path->nodes[0]) != num_extents + 1 ||
		    path->slots[0] != 0)
			goto invalid;
		for (i = 0; i < num_extents; i++) {
			path->slots[0]++;
			btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
			if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY ||
			    key.objectid != extents[i].start ||
			    key.offset != extents[i].length)
				goto invalid;
		}
	}

	ret = 0;
out:
	btrfs_release_path(path);
	return ret;
invalid:
	test_err("free space tree is invalid");
	ret = -EINVAL;
	goto out;

Annotation

Implementation Notes