[PATCH 16/21] bcachefs: bch2_verify_accounting_clean()

[Kent Overstreet <kent.overstreet@linux.dev>]

Verify that the in-memory accounting verifies the on-disk accounting
after a clean shutdown.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
 fs/bcachefs/disk_accounting.c | 27 +++++++++++++++++++++++++++
 fs/bcachefs/disk_accounting.h |  4 +++-
 fs/bcachefs/super.c           |  1 +
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/fs/bcachefs/disk_accounting.c b/fs/bcachefs/disk_accounting.c
index 2884615adc1e..8d7b6ab66e71 100644
--- a/fs/bcachefs/disk_accounting.c
+++ b/fs/bcachefs/disk_accounting.c
@@ -513,6 +513,33 @@ int bch2_dev_usage_init(struct bch_dev *ca, bool gc)
 	return ret;
 }
 
+void bch2_verify_accounting_clean(struct bch_fs *c)
+{
+	bch2_trans_run(c,
+		for_each_btree_key(trans, iter,
+				   BTREE_ID_accounting, POS_MIN,
+				   BTREE_ITER_ALL_SNAPSHOTS, k, ({
+			u64 v[BCH_ACCOUNTING_MAX_COUNTERS];
+			struct bkey_s_c_accounting a = bkey_s_c_to_accounting(k);
+			unsigned nr = bch2_accounting_counters(k.k);
+
+			bch2_accounting_mem_read(c, k.k->p, v, nr);
+
+			if (memcmp(a.v->d, v, nr * sizeof(u64))) {
+				struct printbuf buf = PRINTBUF;
+
+				bch2_bkey_val_to_text(&buf, c, k);
+				prt_str(&buf, " in mem");
+				for (unsigned j = 0; j < nr; j++)
+					prt_printf(&buf, " %llu", v[j]);
+
+				WARN(1, "accounting mismatch: %s", buf.buf);
+				printbuf_exit(&buf);
+			}
+			0;
+		})));
+}
+
 void bch2_accounting_free(struct bch_accounting_mem *acc)
 {
 	darray_exit(&acc->k);
diff --git a/fs/bcachefs/disk_accounting.h b/fs/bcachefs/disk_accounting.h
index 70ac67f4a3cb..a0cf7a0b84a7 100644
--- a/fs/bcachefs/disk_accounting.h
+++ b/fs/bcachefs/disk_accounting.h
@@ -164,7 +164,7 @@ static inline void bch2_accounting_mem_read_counters(struct bch_fs *c, unsigned
 {
 	memset(v, 0, sizeof(*v) * nr);
 
-	struct bch_accounting_mem *acc = &c->accounting[0];
+	struct bch_accounting_mem *acc = &c->accounting[gc];
 	if (unlikely(idx >= acc->k.nr))
 		return;
 
@@ -194,6 +194,8 @@ int bch2_accounting_read(struct bch_fs *);
 int bch2_dev_usage_remove(struct bch_fs *, unsigned);
 int bch2_dev_usage_init(struct bch_dev *, bool);
 
+void bch2_verify_accounting_clean(struct bch_fs *c);
+
 void bch2_accounting_free(struct bch_accounting_mem *);
 void bch2_fs_accounting_exit(struct bch_fs *);
 
diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c
index 6617c8912e51..201d7767e478 100644
--- a/fs/bcachefs/super.c
+++ b/fs/bcachefs/super.c
@@ -355,6 +355,7 @@ void bch2_fs_read_only(struct bch_fs *c)
 		BUG_ON(atomic_long_read(&c->btree_key_cache.nr_dirty));
 		BUG_ON(c->btree_write_buffer.inc.keys.nr);
 		BUG_ON(c->btree_write_buffer.flushing.keys.nr);
+		bch2_verify_accounting_clean(c);
 
 		bch_verbose(c, "marking filesystem clean");
 		bch2_fs_mark_clean(c);
-- 
2.43.0