1 files changed, 175 insertions, 97 deletions

diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h
index 0097a2a20a18..9483ec8913e3 100644
--- a/fs/bcachefs/btree_iter.h
+++ b/fs/bcachefs/btree_iter.h
@@ -1,8 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHEFS_BTREE_ITER_H
 #define _BCACHEFS_BTREE_ITER_H
 
-#include <linux/dynamic_fault.h>
-
+#include "bset.h"
 #include "btree_types.h"
 
 static inline void btree_iter_set_dirty(struct btree_iter *iter,
@@ -17,101 +17,132 @@ static inline struct btree *btree_iter_node(struct btree_iter *iter,
 	return level < BTREE_MAX_DEPTH ? iter->l[level].b : NULL;
 }
 
+static inline bool btree_node_lock_seq_matches(const struct btree_iter *iter,
+					const struct btree *b, unsigned level)
+{
+	/*
+	 * We don't compare the low bits of the lock sequence numbers because
+	 * @iter might have taken a write lock on @b, and we don't want to skip
+	 * the linked iterator if the sequence numbers were equal before taking
+	 * that write lock. The lock sequence number is incremented by taking
+	 * and releasing write locks and is even when unlocked:
+	 */
+	return iter->l[level].lock_seq >> 1 == b->lock.state.seq >> 1;
+}
+
 static inline struct btree *btree_node_parent(struct btree_iter *iter,
 					      struct btree *b)
 {
 	return btree_iter_node(iter, b->level + 1);
 }
 
-static inline bool btree_iter_linked(const struct btree_iter *iter)
+static inline bool btree_trans_has_multiple_iters(const struct btree_trans *trans)
 {
-	return iter->next != iter;
+	return hweight64(trans->iters_linked) > 1;
 }
 
-/**
- * for_each_linked_btree_iter - iterate over all iterators linked with @_iter
- */
-#define for_each_linked_btree_iter(_iter, _linked)			\
-	for ((_linked) = (_iter)->next;					\
-	     (_linked) != (_iter);					\
-	     (_linked) = (_linked)->next)
+static inline int btree_iter_err(const struct btree_iter *iter)
+{
+	return iter->flags & BTREE_ITER_ERROR ? -EIO : 0;
+}
+
+/* Iterate over iters within a transaction: */
 
 static inline struct btree_iter *
-__next_linked_btree_node(struct btree_iter *iter, struct btree *b,
-			 struct btree_iter *linked)
-{
-	do {
-		linked = linked->next;
-
-		if (linked == iter)
-			return NULL;
-
-		/*
-		 * We don't compare the low bits of the lock sequence numbers
-		 * because @iter might have taken a write lock on @b, and we
-		 * don't want to skip the linked iterator if the sequence
-		 * numbers were equal before taking that write lock. The lock
-		 * sequence number is incremented by taking and releasing write
-		 * locks and is even when unlocked:
-		 */
-	} while (linked->l[b->level].b != b ||
-		 linked->lock_seq[b->level] >> 1 != b->lock.state.seq >> 1);
-
-	return linked;
-}
-
-/**
- * for_each_linked_btree_node - iterate over all iterators linked with @_iter
- * that also point to @_b
- *
- * @_b is assumed to be locked by @_iter
- *
- * Filters out iterators that don't have a valid btree_node iterator for @_b -
- * i.e. iterators for which bch2_btree_node_relock() would not succeed.
- */
-#define for_each_linked_btree_node(_iter, _b, _linked)			\
-	for ((_linked) = (_iter);					\
-	     ((_linked) = __next_linked_btree_node(_iter, _b, _linked));)
+__trans_next_iter(struct btree_trans *trans, unsigned idx)
+{
+	EBUG_ON(idx < trans->nr_iters && trans->iters[idx].idx != idx);
+
+	for (; idx < trans->nr_iters; idx++)
+		if (trans->iters_linked & (1ULL << idx))
+			return &trans->iters[idx];
+
+	return NULL;
+}
+
+#define trans_for_each_iter(_trans, _iter)				\
+	for (_iter = __trans_next_iter((_trans), 0);			\
+	     (_iter);							\
+	     _iter = __trans_next_iter((_trans), (_iter)->idx + 1))
+
+static inline bool __iter_has_node(const struct btree_iter *iter,
+				   const struct btree *b)
+{
+	return iter->l[b->level].b == b &&
+		btree_node_lock_seq_matches(iter, b, b->level);
+}
+
+static inline struct btree_iter *
+__trans_next_iter_with_node(struct btree_trans *trans, struct btree *b,
+			    unsigned idx)
+{
+	struct btree_iter *iter = __trans_next_iter(trans, idx);
+
+	while (iter && !__iter_has_node(iter, b))
+		iter = __trans_next_iter(trans, iter->idx + 1);
+
+	return iter;
+}
+
+#define trans_for_each_iter_with_node(_trans, _b, _iter)		\
+	for (_iter = __trans_next_iter_with_node((_trans), (_b), 0);	\
+	     (_iter);							\
+	     _iter = __trans_next_iter_with_node((_trans), (_b),	\
+						 (_iter)->idx + 1))
 
 #ifdef CONFIG_BCACHEFS_DEBUG
 void bch2_btree_iter_verify(struct btree_iter *, struct btree *);
+void bch2_btree_trans_verify_locks(struct btree_trans *);
 #else
 static inline void bch2_btree_iter_verify(struct btree_iter *iter,
-					 struct btree *b) {}
+					  struct btree *b) {}
+static inline void bch2_btree_trans_verify_locks(struct btree_trans *iter) {}
 #endif
 
 void bch2_btree_node_iter_fix(struct btree_iter *, struct btree *,
-			     struct btree_node_iter *, struct bset_tree *,
-			     struct bkey_packed *, unsigned, unsigned);
+			      struct btree_node_iter *, struct bkey_packed *,
+			      unsigned, unsigned);
 
-int bch2_btree_iter_unlock(struct btree_iter *);
-bool __bch2_btree_iter_set_locks_want(struct btree_iter *, unsigned);
+bool bch2_trans_relock(struct btree_trans *);
+void bch2_trans_unlock(struct btree_trans *);
 
-static inline bool bch2_btree_iter_set_locks_want(struct btree_iter *iter,
-						 unsigned new_locks_want)
+bool __bch2_btree_iter_upgrade(struct btree_iter *, unsigned);
+bool __bch2_btree_iter_upgrade_nounlock(struct btree_iter *, unsigned);
+
+static inline bool bch2_btree_iter_upgrade(struct btree_iter *iter,
+					   unsigned new_locks_want)
 {
 	new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 
-	if (iter->locks_want == new_locks_want &&
-	    iter->nodes_intent_locked == (1 << new_locks_want) - 1)
-		return true;
+	return iter->locks_want < new_locks_want
+		? (!iter->trans->nounlock
+		   ? __bch2_btree_iter_upgrade(iter, new_locks_want)
+		   : __bch2_btree_iter_upgrade_nounlock(iter, new_locks_want))
+		: iter->uptodate <= BTREE_ITER_NEED_PEEK;
+}
+
+void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 
-	return __bch2_btree_iter_set_locks_want(iter, new_locks_want);
+static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
+{
+	if (iter->locks_want > (iter->flags & BTREE_ITER_INTENT) ? 1 : 0)
+		__bch2_btree_iter_downgrade(iter, 0);
 }
 
-bool bch2_btree_iter_node_replace(struct btree_iter *, struct btree *);
-void bch2_btree_iter_node_drop_linked(struct btree_iter *, struct btree *);
+void bch2_btree_iter_node_replace(struct btree_iter *, struct btree *);
 void bch2_btree_iter_node_drop(struct btree_iter *, struct btree *);
 
 void bch2_btree_iter_reinit_node(struct btree_iter *, struct btree *);
 
 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
+int bch2_btree_iter_traverse_all(struct btree_trans *);
 
 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 struct btree *bch2_btree_iter_next_node(struct btree_iter *, unsigned);
 
 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
+struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 
 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
@@ -119,37 +150,32 @@ struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 void bch2_btree_iter_set_pos_same_leaf(struct btree_iter *, struct bpos);
 void bch2_btree_iter_set_pos(struct btree_iter *, struct bpos);
 
-void __bch2_btree_iter_init(struct btree_iter *, struct bch_fs *,
-			   enum btree_id, struct bpos,
-			   unsigned , unsigned, unsigned);
-
-static inline void bch2_btree_iter_init(struct btree_iter *iter,
-			struct bch_fs *c, enum btree_id btree_id,
-			struct bpos pos, unsigned flags)
-{
-	__bch2_btree_iter_init(iter, c, btree_id, pos,
-			       flags & BTREE_ITER_INTENT ? 1 : 0, 0,
-			       (btree_id == BTREE_ID_EXTENTS
-				?  BTREE_ITER_IS_EXTENTS : 0)|flags);
-}
-
-void bch2_btree_iter_link(struct btree_iter *, struct btree_iter *);
-void bch2_btree_iter_unlink(struct btree_iter *);
-void bch2_btree_iter_copy(struct btree_iter *, struct btree_iter *);
-
 static inline struct bpos btree_type_successor(enum btree_id id,
 					       struct bpos pos)
 {
 	if (id == BTREE_ID_INODES) {
 		pos.inode++;
 		pos.offset = 0;
-	} else if (id != BTREE_ID_EXTENTS) {
+	} else if (!btree_node_type_is_extents(id)) {
 		pos = bkey_successor(pos);
 	}
 
 	return pos;
 }
 
+static inline struct bpos btree_type_predecessor(enum btree_id id,
+					       struct bpos pos)
+{
+	if (id == BTREE_ID_INODES) {
+		--pos.inode;
+		pos.offset = 0;
+	} else {
+		pos = bkey_predecessor(pos);
+	}
+
+	return pos;
+}
+
 static inline int __btree_iter_cmp(enum btree_id id,
 				   struct bpos pos,
 				   const struct btree_iter *r)
@@ -169,26 +195,29 @@ static inline int btree_iter_cmp(const struct btree_iter *l,
  * Unlocks before scheduling
  * Note: does not revalidate iterator
  */
-static inline void bch2_btree_iter_cond_resched(struct btree_iter *iter)
+static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 {
-	if (need_resched()) {
-		bch2_btree_iter_unlock(iter);
+	if (need_resched() || race_fault()) {
+		bch2_trans_unlock(trans);
 		schedule();
-	} else if (race_fault()) {
-		bch2_btree_iter_unlock(iter);
+		return bch2_trans_relock(trans) ? 0 : -EINTR;
+	} else {
+		return 0;
 	}
 }
 
-#define __for_each_btree_node(_iter, _c, _btree_id, _start,		\
+#define __for_each_btree_node(_trans, _iter, _btree_id, _start,	\
 			      _locks_want, _depth, _flags, _b)		\
-	for (__bch2_btree_iter_init((_iter), (_c), (_btree_id), _start,	\
-				    _locks_want, _depth, _flags),	\
+	for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),	\
+				_start, _locks_want, _depth, _flags),	\
 	     _b = bch2_btree_iter_peek_node(_iter);			\
 	     (_b);							\
 	     (_b) = bch2_btree_iter_next_node(_iter, _depth))
 
-#define for_each_btree_node(_iter, _c, _btree_id, _start, _flags, _b)	\
-	__for_each_btree_node(_iter, _c, _btree_id, _start, 0, 0, _flags, _b)
+#define for_each_btree_node(_trans, _iter, _btree_id, _start,		\
+			    _flags, _b)					\
+	__for_each_btree_node(_trans, _iter, _btree_id, _start,		\
+			      0, 0, _flags, _b)
 
 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 						     unsigned flags)
@@ -201,28 +230,77 @@ static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 						     unsigned flags)
 {
-	bch2_btree_iter_cond_resched(iter);
-
 	return flags & BTREE_ITER_SLOTS
 		? bch2_btree_iter_next_slot(iter)
 		: bch2_btree_iter_next(iter);
 }
 
-#define for_each_btree_key(_iter, _c, _btree_id,  _start, _flags, _k)	\
-	for (bch2_btree_iter_init((_iter), (_c), (_btree_id),		\
-				  (_start), (_flags)),			\
-	     (_k) = __bch2_btree_iter_peek(_iter, _flags);		\
-	     !IS_ERR_OR_NULL((_k).k);					\
-	     (_k) = __bch2_btree_iter_next(_iter, _flags))
+#define for_each_btree_key(_trans, _iter, _btree_id,			\
+			   _start, _flags, _k, _ret)			\
+	for ((_ret) = PTR_ERR_OR_ZERO((_iter) =				\
+			bch2_trans_get_iter((_trans), (_btree_id),	\
+					    (_start), (_flags))) ?:	\
+		      PTR_ERR_OR_ZERO(((_k) =				\
+			__bch2_btree_iter_peek(_iter, _flags)).k);	\
+	     !ret && (_k).k;						\
+	     (_ret) = PTR_ERR_OR_ZERO(((_k) =				\
+			__bch2_btree_iter_next(_iter, _flags)).k))
 
 #define for_each_btree_key_continue(_iter, _flags, _k)			\
 	for ((_k) = __bch2_btree_iter_peek(_iter, _flags);		\
 	     !IS_ERR_OR_NULL((_k).k);					\
 	     (_k) = __bch2_btree_iter_next(_iter, _flags))
 
-static inline int btree_iter_err(struct bkey_s_c k)
+static inline int bkey_err(struct bkey_s_c k)
 {
 	return PTR_ERR_OR_ZERO(k.k);
 }
 
+/* new multiple iterator interface: */
+
+int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);
+int bch2_trans_iter_free(struct btree_trans *, struct btree_iter *);
+int bch2_trans_iter_free_on_commit(struct btree_trans *, struct btree_iter *);
+
+void bch2_trans_unlink_iters(struct btree_trans *, u64);
+
+struct btree_iter *__bch2_trans_get_iter(struct btree_trans *, enum btree_id,
+					 struct bpos, unsigned, u64);
+struct btree_iter *bch2_trans_copy_iter(struct btree_trans *,
+					struct btree_iter *);
+
+static __always_inline u64 __btree_iter_id(void)
+{
+	u64 ret = 0;
+
+	ret <<= 32;
+	ret |= _RET_IP_ & U32_MAX;
+	ret <<= 32;
+	ret |= _THIS_IP_ & U32_MAX;
+	return ret;
+}
+
+static __always_inline struct btree_iter *
+bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id,
+		    struct bpos pos, unsigned flags)
+{
+	return __bch2_trans_get_iter(trans, btree_id, pos, flags,
+				     __btree_iter_id());
+}
+
+struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
+				enum btree_id, struct bpos,
+				unsigned, unsigned, unsigned);
+
+void bch2_trans_begin(struct btree_trans *);
+
+static inline void bch2_trans_begin_updates(struct btree_trans *trans)
+{
+	trans->nr_updates = 0;
+}
+
+void *bch2_trans_kmalloc(struct btree_trans *, size_t);
+void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
+int bch2_trans_exit(struct btree_trans *);
+
 #endif /* _BCACHEFS_BTREE_ITER_H */