bcachefs: btree_iter_live()

New helper to clean things up a bit - also, improve iter->flags
handling.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_iter.c

@@ -1701,7 +1701,8 @@ struct bkey_s_c bch2_btree_iter_peek_with_updates(struct btree_iter *iter)
 		k = __bch2_btree_iter_peek_with_updates(iter);
 
 		if (k.k && bkey_deleted(k.k)) {
-			bch2_btree_iter_advance_pos(iter);
+			if (!bch2_btree_iter_advance_pos(iter))
+				return bkey_s_c_null;
 			continue;
 		}
 
@@ -2008,7 +2009,7 @@ static void btree_trans_iter_alloc_fail(struct btree_trans *trans)
 		       bch2_btree_ids[iter->btree_id],
 		       iter->pos.inode,
 		       iter->pos.offset,
-		       (trans->iters_live & (1ULL << iter->idx)) ? " live" : "",
+		       btree_iter_live(trans, iter) ? " live" : "",
 		       (trans->iters_touched & (1ULL << iter->idx)) ? " touched" : "",
 		       iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT ? " keep" : "",
 		       (void *) iter->ip_allocated);
@@ -2089,31 +2090,20 @@ static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans,
 	if (!best) {
 		iter = btree_trans_iter_alloc(trans);
 		bch2_btree_iter_init(trans, iter, btree_id, pos, flags);
-	} else if ((trans->iters_live & (1ULL << best->idx)) ||
-		   (best->flags & BTREE_ITER_KEEP_UNTIL_COMMIT)) {
+	} else if (btree_iter_keep(trans, best)) {
 		iter = btree_trans_iter_alloc(trans);
 		btree_iter_copy(iter, best);
 	} else {
 		iter = best;
 	}
 
-	iter->flags &= ~BTREE_ITER_KEEP_UNTIL_COMMIT;
-	iter->flags &= ~BTREE_ITER_USER_FLAGS;
-	iter->flags |= flags & BTREE_ITER_USER_FLAGS;
+	flags |= iter->flags & BTREE_ITER_ERROR;
+	iter->flags = flags;
 
-	if (iter->flags & BTREE_ITER_INTENT) {
-		if (!iter->locks_want) {
-			__bch2_btree_iter_unlock(iter);
-			iter->locks_want = 1;
-		}
-	} else
+	if (!(iter->flags & BTREE_ITER_INTENT))
 		bch2_btree_iter_downgrade(iter);
-
-	BUG_ON(iter->btree_id != btree_id);
-	BUG_ON((iter->flags ^ flags) & BTREE_ITER_TYPE);
-	BUG_ON(iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT);
-	BUG_ON(iter->flags & BTREE_ITER_SET_POS_AFTER_COMMIT);
-	BUG_ON(trans->iters_live & (1ULL << iter->idx));
+	else if (!iter->locks_want)
+		__bch2_btree_iter_upgrade_nounlock(iter, 1);
 
 	trans->iters_live	|= 1ULL << iter->idx;
 	trans->iters_touched	|= 1ULL << iter->idx;

fs/bcachefs/btree_iter.h

@@ -289,6 +289,17 @@ struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 				enum btree_id, struct bpos,
 				unsigned, unsigned, unsigned);
 
+static inline bool btree_iter_live(struct btree_trans *trans, struct btree_iter *iter)
+{
+	return (trans->iters_live & (1ULL << iter->idx)) != 0;
+}
+
+static inline bool btree_iter_keep(struct btree_trans *trans, struct btree_iter *iter)
+{
+	return btree_iter_live(trans, iter) ||
+		(iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT);
+}
+
 #define TRANS_RESET_NOTRAVERSE		(1 << 0)
 
 void bch2_trans_reset(struct btree_trans *, unsigned);

fs/bcachefs/btree_types.h

@@ -216,13 +216,6 @@ enum btree_iter_type {
 #define BTREE_ITER_CACHED_NOFILL	(1 << 9)
 #define BTREE_ITER_CACHED_NOCREATE	(1 << 10)
 
-#define BTREE_ITER_USER_FLAGS				\
-	(BTREE_ITER_SLOTS				\
-	|BTREE_ITER_INTENT				\
-	|BTREE_ITER_PREFETCH				\
-	|BTREE_ITER_CACHED_NOFILL			\
-	|BTREE_ITER_CACHED_NOCREATE)
-
 enum btree_iter_uptodate {
 	BTREE_ITER_UPTODATE		= 0,
 	BTREE_ITER_NEED_PEEK		= 1,

fs/bcachefs/btree_update_leaf.c

@@ -512,8 +512,7 @@ static inline int do_bch2_trans_commit(struct btree_trans *trans,
 	 */
 	trans_for_each_iter(trans, iter) {
 		if (iter->nodes_locked != iter->nodes_intent_locked) {
-			if ((iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT) ||
-			    (trans->iters_live & (1ULL << iter->idx))) {
+			if (btree_iter_keep(trans, iter)) {
 				if (!bch2_btree_iter_upgrade(iter, 1)) {
 					trace_trans_restart_upgrade(trans->ip);
 					return -EINTR;
@@ -945,7 +944,7 @@ int __bch2_trans_commit(struct btree_trans *trans)
 		goto err;
 
 	trans_for_each_iter(trans, iter)
-		if ((trans->iters_live & (1ULL << iter->idx)) &&
+		if (btree_iter_live(trans, iter) &&
 		    (iter->flags & BTREE_ITER_SET_POS_AFTER_COMMIT))
 			bch2_btree_iter_set_pos(iter, iter->pos_after_commit);
 out:
@@ -1049,7 +1048,7 @@ int bch2_trans_update(struct btree_trans *trans, struct btree_iter *iter,
 			 * the iterator pos if some other code is using it, so we may
 			 * need to clone it:
 			 */
-			if (trans->iters_live & (1ULL << i->iter->idx)) {
+			if (btree_iter_live(trans, i->iter)) {
 				i->iter = bch2_trans_copy_iter(trans, i->iter);
 
 				i->iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;