3c555beabf
There are two different subvolume/data reloc tree creation routines:
- create_subvol() from convert/main.c
* calls btrfs_copy_root() to create an empty root
This is not safe, as it relies on the source root to be empty.
* calls btrfs_read_fs_root() to add it to the cache and trace it
properly
* calls btrfs_make_root_dir() to initialize the empty new root
- create_data_reloc_tree() from mkfs/main.c
* calls btrfs_create_tree() to create an empty root
* Manually add the root to fs_root cache
This is only safe for data reloc tree as it's never updated
inside btrfs-progs.
But not safe for other subvolume trees.
* manually setup the root dir
Both have their good and bad aspects, so here we introduce a new helper,
btrfs_make_subvolume():
- Calls btrfs_create_tree() to create an empty root
- Calls btrfs_read_fs_root() to setup the cache and tracking properly
- Calls btrfs_make_root_dir() to initialize the root dir
- Calls btrfs_update_root() to reflect the rootdir change
So this new helper can replace both create_subvol() and
create_data_reloc_tree().
Signed-off-by: Qu Wenruo <wqu@suse.com>
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| .. | ||
| Makefile | ||
| common.c | ||
| common.h | ||
| main.c | ||
| rootdir.c | ||
| rootdir.h | ||