bcachefs: Disk space accounting rewrite

Main part of the disk accounting rewrite.

This is a wholesale rewrite of the existing disk space accounting, which
relies on percepu counters that are sharded by journal buffer, and
rolled up and added to each journal write.

With the new scheme, every set of counters is a distinct key in the
accounting btree; this fixes scaling limitations of the old scheme,
where counters took up space in each journal entry and required multiple
percpu counters.

Now, in memory accounting requires a single set of percpu counters - not
multiple for each in flight journal buffer - and in the future we'll
probably also have counters that don't use in memory percpu counters,
they're not strictly required.

An accounting update is now a normal btree update, using the btree write
buffer path. At transaction commit time, we apply accounting updates to
the in memory counters, which are percpu counters indexed in an
eytzinger tree by the accounting key.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index b1a74d3ebc12..03e4f15f34f5 100644
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -205,6 +205,7 @@
 #include <linux/zstd.h>
 
 #include "bcachefs_format.h"
+#include "disk_accounting_types.h"
 #include "errcode.h"
 #include "fifo.h"
 #include "nocow_locking_types.h"
@@ -672,8 +673,6 @@ struct btree_trans_buf {
 	struct btree_trans	*trans;
 };
 
-#define REPLICAS_DELTA_LIST_MAX	(1U << 16)
-
 #define BCACHEFS_ROOT_SUBVOL_INUM					\
 	((subvol_inum) { BCACHEFS_ROOT_SUBVOL,	BCACHEFS_ROOT_INO })
 
@@ -743,10 +742,11 @@ struct bch_fs {
 
 	struct bch_dev __rcu	*devs[BCH_SB_MEMBERS_MAX];
 
+	struct bch_accounting_mem accounting;
+
 	struct bch_replicas_cpu replicas;
 	struct bch_replicas_cpu replicas_gc;
 	struct mutex		replicas_gc_lock;
-	mempool_t		replicas_delta_pool;
 
 	struct journal_entry_res btree_root_journal_res;
 	struct journal_entry_res replicas_journal_res;