bcachefs: Interior btree updates are now fully transactional

We now update the alloc info (bucket sector counts) atomically with
journalling the update to the interior btree nodes, and we also set new
btree roots atomically with the journalled part of the btree update.

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

1 files changed, 28 insertions, 36 deletions

diff --git a/fs/bcachefs/btree_update_interior.h b/fs/bcachefs/btree_update_interior.h
index 5cec87951dc7..17bd1ca1fb78 100644
--- a/fs/bcachefs/btree_update_interior.h
+++ b/fs/bcachefs/btree_update_interior.h
@@ -6,34 +6,13 @@
 #include "btree_locking.h"
 #include "btree_update.h"
 
-struct btree_reserve {
-	struct disk_reservation	disk_res;
-	unsigned		nr;
-	struct btree		*b[BTREE_RESERVE_MAX];
-};
-
 void __bch2_btree_calc_format(struct bkey_format_state *, struct btree *);
 bool bch2_btree_node_format_fits(struct bch_fs *c, struct btree *,
 				struct bkey_format *);
 
-/* Btree node freeing/allocation: */
-
-/*
- * Tracks a btree node that has been (or is about to be) freed in memory, but
- * has _not_ yet been freed on disk (because the write that makes the new
- * node(s) visible and frees the old hasn't completed yet)
- */
-struct pending_btree_node_free {
-	bool			index_update_done;
-
-	__le64			seq;
-	enum btree_id		btree_id;
-	unsigned		level;
-	__BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
-};
+#define BTREE_UPDATE_NODES_MAX		((BTREE_MAX_DEPTH - 2) * 2 + GC_MERGE_NODES)
 
-#define BTREE_UPDATE_JOURNAL_RES		\
-	((BKEY_BTREE_PTR_U64s_MAX + 1) * (BTREE_MAX_DEPTH - 1) * 2)
+#define BTREE_UPDATE_JOURNAL_RES	(BTREE_UPDATE_NODES_MAX * (BKEY_BTREE_PTR_U64s_MAX + 1))
 
 /*
  * Tracks an in progress split/rewrite of a btree node and the update to the
@@ -72,9 +51,8 @@ struct btree_update {
 	unsigned			nodes_written:1;
 
 	enum btree_id			btree_id;
-	u8				level;
 
-	struct btree_reserve		*reserve;
+	struct disk_reservation		disk_res;
 	struct journal_preres		journal_preres;
 
 	/*
@@ -96,17 +74,28 @@ struct btree_update {
 	 */
 	struct journal_entry_pin	journal;
 
-	/*
-	 * Nodes being freed:
-	 * Protected by c->btree_node_pending_free_lock
-	 */
-	struct pending_btree_node_free	pending[BTREE_MAX_DEPTH + GC_MERGE_NODES];
-	unsigned			nr_pending;
+	/* Preallocated nodes we reserve when we start the update: */
+	struct btree			*prealloc_nodes[BTREE_UPDATE_NODES_MAX];
+	unsigned			nr_prealloc_nodes;
+
+	/* Nodes being freed: */
+	struct keylist			old_keys;
+	u64				_old_keys[BTREE_UPDATE_NODES_MAX *
+						  BKEY_BTREE_PTR_VAL_U64s_MAX];
+
+	/* Nodes being added: */
+	struct keylist			new_keys;
+	u64				_new_keys[BTREE_UPDATE_NODES_MAX *
+						  BKEY_BTREE_PTR_VAL_U64s_MAX];
 
 	/* New nodes, that will be made reachable by this update: */
-	struct btree			*new_nodes[BTREE_MAX_DEPTH * 2 + GC_MERGE_NODES];
+	struct btree			*new_nodes[BTREE_UPDATE_NODES_MAX];
 	unsigned			nr_new_nodes;
 
+	u8				open_buckets[BTREE_UPDATE_NODES_MAX *
+						     BCH_REPLICAS_MAX];
+	u8				nr_open_buckets;
+
 	unsigned			journal_u64s;
 	u64				journal_entries[BTREE_UPDATE_JOURNAL_RES];
 
@@ -120,14 +109,12 @@ struct btree_update {
 	u64				inline_keys[BKEY_BTREE_PTR_U64s_MAX * 3];
 };
 
-#define for_each_pending_btree_node_free(c, as, p)			\
-	list_for_each_entry(as, &c->btree_interior_update_list, list)	\
-		for (p = as->pending; p < as->pending + as->nr_pending; p++)
-
 void bch2_btree_node_free_inmem(struct bch_fs *, struct btree *,
 				struct btree_iter *);
 void bch2_btree_node_free_never_inserted(struct bch_fs *, struct btree *);
 
+void bch2_btree_update_get_open_buckets(struct btree_update *, struct btree *);
+
 struct btree *__bch2_btree_node_alloc_replacement(struct btree_update *,
 						  struct btree *,
 						  struct bkey_format);
@@ -139,6 +126,7 @@ bch2_btree_update_start(struct btree_trans *, enum btree_id, unsigned,
 
 void bch2_btree_interior_update_will_free_node(struct btree_update *,
 					       struct btree *);
+void bch2_btree_update_add_new_node(struct btree_update *, struct btree *);
 
 void bch2_btree_insert_node(struct btree_update *, struct btree *,
 			    struct btree_iter *, struct keylist *,
@@ -333,6 +321,10 @@ ssize_t bch2_btree_updates_print(struct bch_fs *, char *);
 
 size_t bch2_btree_interior_updates_nr_pending(struct bch_fs *);
 
+void bch2_journal_entries_to_btree_roots(struct bch_fs *, struct jset *);
+struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *,
+					struct jset_entry *, struct jset_entry *);
+
 void bch2_fs_btree_interior_update_exit(struct bch_fs *);
 int bch2_fs_btree_interior_update_init(struct bch_fs *);