linux-stable/fs/btrfs/tree-mod-log.h
Filipe Manana 4bae788075 btrfs: add and use helper to get lowest sequence number for the tree mod log
There are two places outside the tree mod log module that extract the
lowest sequence number of the tree mod log. These places end up
duplicating code and open coding the logic and internal implementation
details of the tree mod log. So add a helper to the tree mod log module
and header that returns the lowest sequence number or 0 if there aren't
any tree mod log users at the moment.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19 17:25:17 +02:00

53 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef BTRFS_TREE_MOD_LOG_H
#define BTRFS_TREE_MOD_LOG_H
#include "ctree.h"
/* Represents a tree mod log user. */
struct btrfs_seq_list {
struct list_head list;
u64 seq;
};
#define BTRFS_SEQ_LIST_INIT(name) { .list = LIST_HEAD_INIT((name).list), .seq = 0 }
#define BTRFS_SEQ_LAST ((u64)-1)
enum btrfs_mod_log_op {
BTRFS_MOD_LOG_KEY_REPLACE,
BTRFS_MOD_LOG_KEY_ADD,
BTRFS_MOD_LOG_KEY_REMOVE,
BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING,
BTRFS_MOD_LOG_KEY_REMOVE_WHILE_MOVING,
BTRFS_MOD_LOG_MOVE_KEYS,
BTRFS_MOD_LOG_ROOT_REPLACE,
};
u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info,
struct btrfs_seq_list *elem);
void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info,
struct btrfs_seq_list *elem);
int btrfs_tree_mod_log_insert_root(struct extent_buffer *old_root,
struct extent_buffer *new_root,
bool log_removal);
int btrfs_tree_mod_log_insert_key(struct extent_buffer *eb, int slot,
enum btrfs_mod_log_op op, gfp_t flags);
int btrfs_tree_mod_log_free_eb(struct extent_buffer *eb);
struct extent_buffer *btrfs_tree_mod_log_rewind(struct btrfs_fs_info *fs_info,
struct btrfs_path *path,
struct extent_buffer *eb,
u64 time_seq);
struct extent_buffer *btrfs_get_old_root(struct btrfs_root *root, u64 time_seq);
int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq);
int btrfs_tree_mod_log_eb_copy(struct extent_buffer *dst,
struct extent_buffer *src,
unsigned long dst_offset,
unsigned long src_offset,
int nr_items);
int btrfs_tree_mod_log_insert_move(struct extent_buffer *eb,
int dst_slot, int src_slot,
int nr_items);
u64 btrfs_tree_mod_log_lowest_seq(struct btrfs_fs_info *fs_info);
#endif