linux/fs/btrfs/discard.h
Dennis Zhou 7fe6d45e40 btrfs: have multiple discard lists
Non-block group destruction discarding currently only had a single list
with no minimum discard length. This can lead to caravaning more
meaningful discards behind a heavily fragmented block group.

This adds support for multiple lists with minimum discard lengths to
prevent the caravan effect. We promote block groups back up when we
exceed the BTRFS_ASYNC_DISCARD_MAX_FILTER size, currently we support
only 2 lists with filters of 1MB and 32KB respectively.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:00 +01:00

42 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef BTRFS_DISCARD_H
#define BTRFS_DISCARD_H
#include <linux/sizes.h>
struct btrfs_fs_info;
struct btrfs_discard_ctl;
struct btrfs_block_group;
/* Discard size limits */
#define BTRFS_ASYNC_DISCARD_DEFAULT_MAX_SIZE (SZ_64M)
#define BTRFS_ASYNC_DISCARD_MAX_FILTER (SZ_1M)
#define BTRFS_ASYNC_DISCARD_MIN_FILTER (SZ_32K)
/* List operations */
void btrfs_discard_check_filter(struct btrfs_block_group *block_group, u64 bytes);
/* Work operations */
void btrfs_discard_cancel_work(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group);
void btrfs_discard_queue_work(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group);
void btrfs_discard_schedule_work(struct btrfs_discard_ctl *discard_ctl,
bool override);
bool btrfs_run_discard_work(struct btrfs_discard_ctl *discard_ctl);
/* Update operations */
void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl);
void btrfs_discard_update_discardable(struct btrfs_block_group *block_group,
struct btrfs_free_space_ctl *ctl);
/* Setup/cleanup operations */
void btrfs_discard_punt_unused_bgs_list(struct btrfs_fs_info *fs_info);
void btrfs_discard_resume(struct btrfs_fs_info *fs_info);
void btrfs_discard_stop(struct btrfs_fs_info *fs_info);
void btrfs_discard_init(struct btrfs_fs_info *fs_info);
void btrfs_discard_cleanup(struct btrfs_fs_info *fs_info);
#endif