bcachefs: Persist 64 bit io clocks

Originally, bcachefs - going back to bcache - stored, for each bucket, a
16 bit counter corresponding to how long it had been since the bucket
was read from. But, this required periodically rescaling counters on
every bucket to avoid wraparound. That wasn't an issue in bcache, where
we'd perodically rewrite the per bucket metadata all at once, but in
bcachefs we're trying to avoid having to walk every single bucket.

This patch switches to persisting 64 bit io clocks, corresponding to the
64 bit bucket timestaps introduced in the previous patch with
KEY_TYPE_alloc_v2.

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

1 files changed, 28 insertions, 5 deletions

diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c
index 7e726db77881..a82548983dbd 100644
--- a/fs/bcachefs/journal_io.c
+++ b/fs/bcachefs/journal_io.c
@@ -426,6 +426,32 @@ fsck_err:
 	return ret;
 }
 
+static int journal_entry_validate_clock(struct bch_fs *c,
+					struct jset *jset,
+					struct jset_entry *entry,
+					int write)
+{
+	struct jset_entry_clock *clock =
+		container_of(entry, struct jset_entry_clock, entry);
+	unsigned bytes = jset_u64s(le16_to_cpu(entry->u64s)) * sizeof(u64);
+	int ret = 0;
+
+	if (journal_entry_err_on(bytes != sizeof(*clock),
+				 c, "invalid journal entry clock: bad size")) {
+		journal_entry_null_range(entry, vstruct_next(entry));
+		return ret;
+	}
+
+	if (journal_entry_err_on(clock->rw > 1,
+				 c, "invalid journal entry clock: bad rw")) {
+		journal_entry_null_range(entry, vstruct_next(entry));
+		return ret;
+	}
+
+fsck_err:
+	return ret;
+}
+
 struct jset_entry_ops {
 	int (*validate)(struct bch_fs *, struct jset *,
 			struct jset_entry *, int);
@@ -1361,8 +1387,8 @@ void bch2_journal_write(struct closure *cl)
 
 	end	= bch2_btree_roots_to_journal_entries(c, jset->start, end);
 
-	end	= bch2_journal_super_entries_add_common(c, end,
-						le64_to_cpu(jset->seq));
+	bch2_journal_super_entries_add_common(c, &end,
+				le64_to_cpu(jset->seq));
 	u64s	= (u64 *) end - (u64 *) start;
 	BUG_ON(u64s > j->entry_u64s_reserved);
 
@@ -1371,10 +1397,7 @@ void bch2_journal_write(struct closure *cl)
 
 	journal_write_compact(jset);
 
-	jset->read_clock	= cpu_to_le16(c->bucket_clock[READ].hand);
-	jset->write_clock	= cpu_to_le16(c->bucket_clock[WRITE].hand);
 	jset->magic		= cpu_to_le64(jset_magic(c));
-
 	jset->version		= c->sb.version < bcachefs_metadata_version_new_versioning
 		? cpu_to_le32(BCH_JSET_VERSION_OLD)
 		: cpu_to_le32(c->sb.version);