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btrfs-progs: Create uuid tree with proper contents 

Commit 2a496a5b8b ("btrfs-progs: mkfs: precreate the uuid tree")
creates uuid tree at mkfs time.  However it doesn't populate uuid tree
correctly nor creates an empty root.

It uses create_tree(), which just
copies the content of fs root, containing a meaningless INODE_ITEM:

v4.15 mkfs (no uuid tree creation) + kernel mount:
  uuid tree key (UUID_TREE ROOT_ITEM 0)
  leaf 30572544 items 1 free space 16250 generation 7 owner UUID_TREE
  leaf 30572544 flags 0x1(WRITTEN) backref revision 1
  fs uuid 33ecddef-fc86-481a-93ce-846b01c11376
  chunk uuid 9e58f646-b0da-43ca-9c7d-8bbe3e120246
	item 0 key (0x92457c59d31491be UUID_KEY_SUBVOL 0xef908b5e79aa76a1) itemoff 16275 itemsize 8
		subvol_id 5

v4.19.1 mkfs (incorrect one), no kernel mount:
  uuid tree key (UUID_TREE ROOT_ITEM 0)
  leaf 30507008 items 2 free space 16061 generation 4 owner UUID_TREE
  leaf 30507008 flags 0x1(WRITTEN) backref revision 1
  fs uuid 162f5333-9b5d-4217-877c-ddaeaa79398e
  chunk uuid 7bc2c5c6-a6d2-4eec-a513-142b549c6541
	item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160
		generation 3 transid 0 size 0 nbytes 16384
		block group 0 mode 40755 links 1 uid 0 gid 0 rdev 0
		sequence 0 flags 0x0(none)
	item 1 key (256 INODE_REF 256) itemoff 16111 itemsize 12
		index 0 namelen 2 name: ..

This patchset will fix it by populuating uuid tree properly:
(NOTE: due to tree-checker, kernel doesn't accept empty uuid tree, so we
can only fix it by populating uuid tree correctly)

With this patchset, no kernel mount:
  uuid tree key (UUID_TREE ROOT_ITEM 0)
  leaf 30507008 items 1 free space 16250 generation 4 owner UUID_TREE
  leaf 30507008 flags 0x1(WRITTEN) backref revision 1
  fs uuid ae53079e-dbbc-409b-a565-5326c7b27731
  chunk uuid b5fb1bea-f20d-4af1-80f8-6ca3f0038d67
	item 0 key (0x334ba6b032d89c07 UUID_KEY_SUBVOL 0x86cde09cb78bcca0) itemoff 16275 itemsize 8
		subvol_id 5

For kernel, except tree-checker needs an non-empty uuid tree, both of
the above behavior won't cause problem, but it's always better to keep a
good standardized behavior.

Fixes: 2a496a5b8b ("btrfs-progs: mkfs: precreate the uuid tree")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2019-01-03 15:32:21 +08:00 committed by David Sterba
parent 75b5eabb61
commit 8addcab0d0
1 changed files with 26 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
mkfs/main.c
View File

@ -310,38 +310,6 @@ static int create_raid_groups(struct btrfs_trans_handle *trans,
return ret;
}
static int create_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid)
{
struct btrfs_key location;
struct btrfs_root_item root_item;
struct extent_buffer *tmp;
u8 uuid[BTRFS_UUID_SIZE] = {0};
int ret;
ret = btrfs_copy_root(trans, root, root->node, &tmp, objectid);
if (ret)
return ret;
memcpy(&root_item, &root->root_item, sizeof(root_item));
btrfs_set_root_bytenr(&root_item, tmp->start);
btrfs_set_root_level(&root_item, btrfs_header_level(tmp));
btrfs_set_root_generation(&root_item, trans->transid);
/* clear uuid and o/ctime of source tree */
memcpy(root_item.uuid, uuid, BTRFS_UUID_SIZE);
btrfs_set_stack_timespec_sec(&root_item.otime, 0);
btrfs_set_stack_timespec_sec(&root_item.ctime, 0);
free_extent_buffer(tmp);
location.objectid = objectid;
location.type = BTRFS_ROOT_ITEM_KEY;
location.offset = 0;
ret = btrfs_insert_root(trans, root->fs_info->tree_root,
&location, &root_item);
return ret;
}
static void print_usage(int ret)
{
printf("Usage: mkfs.btrfs [options] dev [ dev ... ]\n");
@ -777,6 +745,31 @@ out:
return ret;
}
static int create_uuid_tree(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *root;
int ret = 0;
ASSERT(fs_info->uuid_root == NULL);
root = btrfs_create_tree(trans, fs_info, BTRFS_UUID_TREE_OBJECTID);
if (IS_ERR(root)) {
ret = PTR_ERR(root);
goto out;
}
add_root_to_dirty_list(root);
fs_info->uuid_root = root;
ret = btrfs_uuid_tree_add(trans, fs_info->fs_root->root_item.uuid,
BTRFS_UUID_KEY_SUBVOL,
fs_info->fs_root->root_key.objectid);
if (ret < 0)
btrfs_abort_transaction(trans, ret);
out:
return ret;
}
int main(int argc, char **argv)
{
char *file;
@ -1277,7 +1270,7 @@ raid_groups:
goto out;
}
ret = create_tree(trans, root, BTRFS_UUID_TREE_OBJECTID);
ret = create_uuid_tree(trans);
if (ret)
warning(
"unable to create uuid tree, will be created after mount: %d", ret);