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btrfs-progs/common/root-tree-utils.h

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btrfs-progs: introduce btrfs_make_subvolume() 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>
2024-07-02 07:36:25 +00:00
/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef __ROOT_TREE_UTILS_H__
#define __ROOT_TREE_UTILS_H__
#include "kernel-shared/transaction.h"
int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid);
int btrfs_make_subvolume(struct btrfs_trans_handle *trans, u64 objectid);
btrfs-progs: use btrfs_link_subvolume() to replace btrfs_mksubvol() The function btrfs_mksubvol() is very different between btrfs-progs and kernel, the former version is really just linking a subvolume to another directory inode, but the kernel version is really to make a completely new subvolume. Instead of same-named function, introduce btrfs_link_subvolume() and use it to replace the old btrfs_mksubvol(). This is done by: - Introduce btrfs_link_subvolume() Which does extra checks before doing any modification: * Make sure the target inode is a directory * Make sure no filename conflict Then do the linkage: * Add the dir_item/dir_index into the parent inode * Add the forward and backward root refs into tree root - Introduce link_image_subvolume() helper Currently btrfs_mksubvol() has a dedicated convert filename retry behavior, which is unnecessary and should be done by the convert code. Now move the filename retry behavior into the helper. - Remove btrfs_mksubvol() Since there is only one caller utilizing btrfs_mksubvol(), and it's now gone, we can remove the old btrfs_mksubvol(). Signed-off-by: Qu Wenruo <wqu@suse.com>
2024-07-15 04:01:30 +00:00
int btrfs_link_subvolume(struct btrfs_trans_handle *trans,
struct btrfs_root *parent_root,
u64 parent_dir, const char *name,
int namelen, struct btrfs_root *subvol);
btrfs-progs: introduce btrfs_rebuild_uuid_tree() for mkfs and btrfs-convert Currently mkfs uses its own create_uuid_tree(), but that function is only handling FS_TREE. This means for btrfs-convert we do not generate the uuid tree, nor add the UUID of the image subvolume. This can be a problem if we're going to support multiple subvolumes during mkfs time. To address this, introduce a new helper, btrfs_rebuild_uuid_tree(): - Create a new uuid tree if there is not one - Remove all the existing items from uuid tree - Iterate through all subvolumes * If the subvolume has no valid UUID, regenerate one * Add the uuid entry for the subvolume UUID * If the subvolume has received UUID, also add it to UUID tree By this, this new helper can handle all the uuid tree generation needs for: - Current mkfs Only one uuid entry for FS_TREE - Current btrfs-convert Only FS_TREE and the image subvolume - Future multi-subvolume mkfs As we do the scan for all subvolumes. - Future "btrfs rescue rebuild-uuid-tree" Signed-off-by: Qu Wenruo <wqu@suse.com>
2024-07-26 07:29:10 +00:00
int btrfs_rebuild_uuid_tree(struct btrfs_fs_info *fs_info);
btrfs-progs: introduce btrfs_make_subvolume() 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>
2024-07-02 07:36:25 +00:00
#endif