bcachefs: Refactor journal entry adding

This takes copying the payload out of bch2_journal_add_entry(), which
means we can use it for journal_transaction_name() - also prep work for
journalling overwrites.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/btree_update_leaf.c

@@ -309,25 +309,15 @@ static inline int bch2_trans_journal_res_get(struct btree_trans *trans,
 static noinline void journal_transaction_name(struct btree_trans *trans)
 {
 	struct bch_fs *c = trans->c;
-	struct jset_entry *entry = journal_res_entry(&c->journal, &trans->journal_res);
-	struct jset_entry_log *l = container_of(entry, struct jset_entry_log, entry);
-	unsigned u64s = JSET_ENTRY_LOG_U64s - 1;
-	unsigned b, buflen = u64s * sizeof(u64);
-
-	l->entry.u64s		= cpu_to_le16(u64s);
-	l->entry.btree_id	= 0;
-	l->entry.level		= 0;
-	l->entry.type		= BCH_JSET_ENTRY_log;
-	l->entry.pad[0]		= 0;
-	l->entry.pad[1]		= 0;
-	l->entry.pad[2]		= 0;
-	b = min_t(unsigned, strlen(trans->fn), buflen);
-	memcpy(l->d, trans->fn, b);
-	while (b < buflen)
-		l->d[b++] = '\0';
-
-	trans->journal_res.offset	+= JSET_ENTRY_LOG_U64s;
-	trans->journal_res.u64s		-= JSET_ENTRY_LOG_U64s;
+	struct journal *j = &c->journal;
+	struct jset_entry *entry =
+		bch2_journal_add_entry(j, &trans->journal_res,
+				       BCH_JSET_ENTRY_log, 0, 0,
+				       JSET_ENTRY_LOG_U64s);
+	struct jset_entry_log *l =
+		container_of(entry, struct jset_entry_log, entry);
+
+	strncpy(l->d, trans->fn, JSET_ENTRY_LOG_U64s * sizeof(u64));
 }
 
 static inline enum btree_insert_ret
@@ -416,10 +406,13 @@ static inline void do_btree_insert_one(struct btree_trans *trans,
 
 	if (likely(!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY)) &&
 	    !(i->flags & BTREE_UPDATE_NOJOURNAL)) {
-		bch2_journal_add_keys(j, &trans->journal_res,
-				      i->btree_id,
-				      i->level,
-				      i->k);
+		struct jset_entry *entry;
+
+		entry = bch2_journal_add_entry(j, &trans->journal_res,
+				       BCH_JSET_ENTRY_btree_keys,
+				       i->btree_id, i->level,
+				       i->k->k.u64s);
+		bkey_copy(&entry->start[0], i->k);
 
 		if (trans->journal_seq)
 			*trans->journal_seq = trans->journal_res.seq;
@@ -1127,7 +1120,7 @@ int __bch2_trans_commit(struct btree_trans *trans)
 	trans->journal_transaction_names = READ_ONCE(c->opts.journal_transaction_names);
 
 	if (trans->journal_transaction_names)
-		trans->journal_u64s += JSET_ENTRY_LOG_U64s;
+		trans->journal_u64s += jset_u64s(JSET_ENTRY_LOG_U64s);
 
 	trans_for_each_update(trans, i) {
 		BUG_ON(!i->path->should_be_locked);

fs/bcachefs/journal.h

@@ -199,9 +199,9 @@ journal_res_entry(struct journal *j, struct journal_res *res)
 	return vstruct_idx(j->buf[res->idx].data, res->offset);
 }
 
-static inline unsigned journal_entry_set(struct jset_entry *entry, unsigned type,
+static inline unsigned journal_entry_init(struct jset_entry *entry, unsigned type,
 					  enum btree_id id, unsigned level,
-					  const void *data, unsigned u64s)
+					  unsigned u64s)
 {
 	entry->u64s	= cpu_to_le16(u64s);
 	entry->btree_id = id;
@@ -210,32 +210,33 @@ static inline unsigned journal_entry_set(struct jset_entry *entry, unsigned type
 	entry->pad[0]	= 0;
 	entry->pad[1]	= 0;
 	entry->pad[2]	= 0;
-	memcpy_u64s_small(entry->_data, data, u64s);
-
 	return jset_u64s(u64s);
 }
 
-static inline void bch2_journal_add_entry(struct journal *j, struct journal_res *res,
-					  unsigned type, enum btree_id id,
-					  unsigned level,
+static inline unsigned journal_entry_set(struct jset_entry *entry, unsigned type,
+					  enum btree_id id, unsigned level,
 					  const void *data, unsigned u64s)
 {
-	unsigned actual = journal_entry_set(journal_res_entry(j, res),
-			       type, id, level, data, u64s);
+	unsigned ret = journal_entry_init(entry, type, id, level, u64s);
+
+	memcpy_u64s_small(entry->_data, data, u64s);
+	return ret;
+}
+
+static inline struct jset_entry *
+bch2_journal_add_entry(struct journal *j, struct journal_res *res,
+			 unsigned type, enum btree_id id,
+			 unsigned level, unsigned u64s)
+{
+	struct jset_entry *entry = journal_res_entry(j, res);
+	unsigned actual = journal_entry_init(entry, type, id, level, u64s);
 
 	EBUG_ON(!res->ref);
 	EBUG_ON(actual > res->u64s);
 
 	res->offset	+= actual;
 	res->u64s	-= actual;
-}
-
-static inline void bch2_journal_add_keys(struct journal *j, struct journal_res *res,
-					enum btree_id id, unsigned level,
-					const struct bkey_i *k)
-{
-	bch2_journal_add_entry(j, res, BCH_JSET_ENTRY_btree_keys,
-			       id, level, k, k->k.u64s);
+	return entry;
 }
 
 static inline bool journal_entry_empty(struct jset *j)
@@ -283,7 +284,7 @@ static inline void bch2_journal_res_put(struct journal *j,
 	while (res->u64s)
 		bch2_journal_add_entry(j, res,
 				       BCH_JSET_ENTRY_btree_keys,
-				       0, 0, NULL, 0);
+				       0, 0, 0);
 
 	bch2_journal_buf_put(j, res->idx);