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btrfs-progs: check: lowmem: introduce mark/clear_block_groups_full

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Excluding or pining all metadata blocks is time-inefficient for large
filesystems.  Here is another way to mark all metadata block groups full
and allocate new chunks for COW. Then new reserved extents never
overwrite extents.

Introduce modify_block_groups_cache() to modify all blocks groups
cache state and set all extents in block groups unfree in free space
cache.
mark/clear_block_groups_full() are wrappers of above function.

Suggested-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Su Yue 2018-05-08 16:29:59 +08:00 committed by David Sterba
parent d8020d5f69
commit 8586c84e8e
1 changed files with 93 additions and 0 deletions
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93
check/mode-lowmem.c
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@ -233,6 +233,99 @@ static int update_nodes_refs(struct btrfs_root *root, u64 bytenr,
return 0;
}
/*
* Mark all extents unfree in the block group. And set @block_group->cached
* according to @cache.
*/
static int modify_block_group_cache(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group, int cache)
{
struct extent_io_tree *free_space_cache = &fs_info->free_space_cache;
u64 start = block_group->key.objectid;
u64 end = start + block_group->key.offset;
if (cache && !block_group->cached) {
block_group->cached = 1;
clear_extent_dirty(free_space_cache, start, end - 1);
}
if (!cache && block_group->cached) {
block_group->cached = 0;
clear_extent_dirty(free_space_cache, start, end - 1);
}
return 0;
}
/*
* Modify block groups which have @flags unfree in free space cache.
*
* @cache: if 0, clear block groups cache state;
* not 0, mark blocks groups cached.
*/
static int modify_block_groups_cache(struct btrfs_fs_info *fs_info, u64 flags,
int cache)
{
struct btrfs_root *root = fs_info->extent_root;
struct btrfs_key key;
struct btrfs_path path;
struct btrfs_block_group_cache *bg_cache;
struct btrfs_block_group_item *bi;
struct btrfs_block_group_item bg_item;
struct extent_buffer *eb;
int slot;
int ret;
key.objectid = 0;
key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
key.offset = 0;
btrfs_init_path(&path);
ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
if (ret < 0) {
error("fail to search block groups due to %s", strerror(-ret));
goto out;
}
while (1) {
eb = path.nodes[0];
slot = path.slots[0];
btrfs_item_key_to_cpu(eb, &key, slot);
bg_cache = btrfs_lookup_block_group(fs_info, key.objectid);
if (!bg_cache) {
ret = -ENOENT;
goto out;
}
bi = btrfs_item_ptr(eb, slot, struct btrfs_block_group_item);
read_extent_buffer(eb, &bg_item, (unsigned long)bi,
sizeof(bg_item));
if (btrfs_block_group_flags(&bg_item) & flags)
modify_block_group_cache(fs_info, bg_cache, cache);
ret = btrfs_next_item(root, &path);
if (ret > 0) {
ret = 0;
goto out;
}
if (ret < 0)
goto out;
}
out:
btrfs_release_path(&path);
return ret;
}
static int mark_block_groups_full(struct btrfs_fs_info *fs_info, u64 flags)
{
return modify_block_groups_cache(fs_info, flags, 1);
}
static int clear_block_groups_full(struct btrfs_fs_info *fs_info, u64 flags)
{
return modify_block_groups_cache(fs_info, flags, 0);
}
/*
* This function only handles BACKREF_MISSING,
* If corresponding extent item exists, increase the ref, else insert an extent