bcachefs: KEY_TYPE_accounting

New key type for the disk space accounting rewrite.

 - Holds a variable sized array of u64s (may be more than one for
   accounting e.g. compressed and uncompressed size, or buckets and
   sectors for a given data type)

 - Updates are deltas, not new versions of the key: this means updates
   to accounting can happen via the btree write buffer, which we'll be
   teaching to accumulate deltas.

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

1 files changed, 70 insertions, 0 deletions

diff --git a/fs/bcachefs/disk_accounting.c b/fs/bcachefs/disk_accounting.c
new file mode 100644
index 000000000000..db501c6cf3ee
--- /dev/null
+++ b/fs/bcachefs/disk_accounting.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "btree_update.h"
+#include "buckets.h"
+#include "disk_accounting.h"
+#include "replicas.h"
+
+static const char * const disk_accounting_type_strs[] = {
+#define x(t, n, ...) [n] = #t,
+	BCH_DISK_ACCOUNTING_TYPES()
+#undef x
+	NULL
+};
+
+int bch2_accounting_invalid(struct bch_fs *c, struct bkey_s_c k,
+			    enum bch_validate_flags flags,
+			    struct printbuf *err)
+{
+	return 0;
+}
+
+void bch2_accounting_key_to_text(struct printbuf *out, struct disk_accounting_pos *k)
+{
+	if (k->type >= BCH_DISK_ACCOUNTING_TYPE_NR) {
+		prt_printf(out, "unknown type %u", k->type);
+		return;
+	}
+
+	prt_str(out, disk_accounting_type_strs[k->type]);
+	prt_str(out, " ");
+
+	switch (k->type) {
+	case BCH_DISK_ACCOUNTING_nr_inodes:
+		break;
+	case BCH_DISK_ACCOUNTING_persistent_reserved:
+		prt_printf(out, "replicas=%u", k->persistent_reserved.nr_replicas);
+		break;
+	case BCH_DISK_ACCOUNTING_replicas:
+		bch2_replicas_entry_to_text(out, &k->replicas);
+		break;
+	case BCH_DISK_ACCOUNTING_dev_data_type:
+		prt_printf(out, "dev=%u data_type=", k->dev_data_type.dev);
+		bch2_prt_data_type(out, k->dev_data_type.data_type);
+		break;
+	case BCH_DISK_ACCOUNTING_dev_stripe_buckets:
+		prt_printf(out, "dev=%u", k->dev_stripe_buckets.dev);
+		break;
+	}
+}
+
+void bch2_accounting_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
+{
+	struct bkey_s_c_accounting acc = bkey_s_c_to_accounting(k);
+	struct disk_accounting_pos acc_k;
+	bpos_to_disk_accounting_pos(&acc_k, k.k->p);
+
+	bch2_accounting_key_to_text(out, &acc_k);
+
+	for (unsigned i = 0; i < bch2_accounting_counters(k.k); i++)
+		prt_printf(out, " %lli", acc.v->d[i]);
+}
+
+void bch2_accounting_swab(struct bkey_s k)
+{
+	for (u64 *p = (u64 *) k.v;
+	     p < (u64 *) bkey_val_end(k);
+	     p++)
+		*p = swab64(*p);
+}