linux/fs/bcachefs/rebalance.h

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_REBALANCE_H
#define _BCACHEFS_REBALANCE_H
#include "rebalance_types.h"
bcachefs: rebalance_work This adds a new btree, rebalance_work, to eliminate scanning required for finding extents that need work done on them in the background - i.e. for the background_target and background_compression options. rebalance_work is a bitset btree, where a KEY_TYPE_set corresponds to an extent in the extents or reflink btree at the same pos. A new extent field is added, bch_extent_rebalance, which indicates that this extent has work that needs to be done in the background - and which options to use. This allows per-inode options to be propagated to indirect extents - at least in some circumstances. In this patch, changing IO options on a file will not propagate the new options to indirect extents pointed to by that file. Updating (setting/clearing) the rebalance_work btree is done by the extent trigger, which looks at the bch_extent_rebalance field. Scanning is still requrired after changing IO path options - either just for a given inode, or for the whole filesystem. We indicate that scanning is required by adding a KEY_TYPE_cookie key to the rebalance_work btree: the cookie counter is so that we can detect that scanning is still required when an option has been flipped mid-way through an existing scan. Future possible work: - Propagate options to indirect extents when being changed - Add other IO path options - nr_replicas, ec, to rebalance_work so they can be applied in the background when they change - Add a counter, for bcachefs fs usage output, showing the pending amount of rebalance work: we'll probably want to do this after the disk space accounting rewrite (moving it to a new btree) Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-20 17:33:14 +00:00
int bch2_set_rebalance_needs_scan(struct bch_fs *, u64 inum);
int bch2_set_fs_needs_rebalance(struct bch_fs *);
static inline void rebalance_wakeup(struct bch_fs *c)
{
struct task_struct *p;
rcu_read_lock();
p = rcu_dereference(c->rebalance.thread);
if (p)
wake_up_process(p);
rcu_read_unlock();
}
bcachefs: rebalance_work This adds a new btree, rebalance_work, to eliminate scanning required for finding extents that need work done on them in the background - i.e. for the background_target and background_compression options. rebalance_work is a bitset btree, where a KEY_TYPE_set corresponds to an extent in the extents or reflink btree at the same pos. A new extent field is added, bch_extent_rebalance, which indicates that this extent has work that needs to be done in the background - and which options to use. This allows per-inode options to be propagated to indirect extents - at least in some circumstances. In this patch, changing IO options on a file will not propagate the new options to indirect extents pointed to by that file. Updating (setting/clearing) the rebalance_work btree is done by the extent trigger, which looks at the bch_extent_rebalance field. Scanning is still requrired after changing IO path options - either just for a given inode, or for the whole filesystem. We indicate that scanning is required by adding a KEY_TYPE_cookie key to the rebalance_work btree: the cookie counter is so that we can detect that scanning is still required when an option has been flipped mid-way through an existing scan. Future possible work: - Propagate options to indirect extents when being changed - Add other IO path options - nr_replicas, ec, to rebalance_work so they can be applied in the background when they change - Add a counter, for bcachefs fs usage output, showing the pending amount of rebalance work: we'll probably want to do this after the disk space accounting rewrite (moving it to a new btree) Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-20 17:33:14 +00:00
void bch2_rebalance_status_to_text(struct printbuf *, struct bch_fs *);
void bch2_rebalance_stop(struct bch_fs *);
int bch2_rebalance_start(struct bch_fs *);
void bch2_fs_rebalance_init(struct bch_fs *);
#endif /* _BCACHEFS_REBALANCE_H */