bcachefs: btree_id_cached()

Add a new helper that returns true if the given btree ID uses the btree
key cache. This enables some new cleanups, since the helper can check
the options for whether caching is enabled on a given btree.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/bcachefs.h

@@ -716,6 +716,7 @@ struct bch_fs {
 	bool			btree_trans_barrier_initialized;
 
 	struct btree_key_cache	btree_key_cache;
+	unsigned		btree_key_cache_btrees;
 
 	struct workqueue_struct	*btree_update_wq;
 	struct workqueue_struct	*btree_io_complete_wq;
@@ -952,6 +953,11 @@ static inline size_t btree_sectors(const struct bch_fs *c)
 	return c->opts.btree_node_size >> 9;
 }
 
+static inline bool btree_id_cached(const struct bch_fs *c, enum btree_id btree)
+{
+	return c->btree_key_cache_btrees & (1U << btree);
+}
+
 static inline struct timespec64 bch2_time_to_timespec(const struct bch_fs *c, s64 time)
 {
 	struct timespec64 t;

fs/bcachefs/btree_iter.c

@@ -2860,6 +2860,9 @@ static void __bch2_trans_iter_init(struct btree_trans *trans,
 	if (trans->journal_replay_not_finished)
 		flags |= BTREE_ITER_WITH_JOURNAL;
 
+	if (!btree_id_cached(trans->c, btree_id))
+		flags &= ~BTREE_ITER_CACHED;
+
 	iter->trans	= trans;
 	iter->path	= NULL;
 	iter->update_path = NULL;

fs/bcachefs/fs.c

@@ -105,7 +105,7 @@ void bch2_inode_update_after_write(struct btree_trans *trans,
 
 	bch2_assert_pos_locked(trans, BTREE_ID_inodes,
 			       POS(0, bi->bi_inum),
-			       0 && c->opts.inodes_use_key_cache);
+			       c->opts.inodes_use_key_cache);
 
 	set_nlink(&inode->v, bch2_inode_nlink_get(bi));
 	i_uid_write(&inode->v, bi->bi_uid);
@@ -1473,7 +1473,7 @@ static void bch2_evict_inode(struct inode *vinode)
 				KEY_TYPE_QUOTA_WARN);
 		bch2_quota_acct(c, inode->ei_qid, Q_INO, -1,
 				KEY_TYPE_QUOTA_WARN);
-		bch2_inode_rm(c, inode_inum(inode), true);
+		bch2_inode_rm(c, inode_inum(inode));
 	}
 }
 

fs/bcachefs/inode.c

@@ -252,15 +252,13 @@ int bch2_inode_peek(struct btree_trans *trans,
 	u32 snapshot;
 	int ret;
 
-	if (trans->c->opts.inodes_use_key_cache)
-		flags |= BTREE_ITER_CACHED;
-
 	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
 	if (ret)
 		return ret;
 
 	bch2_trans_iter_init(trans, iter, BTREE_ID_inodes,
-			     SPOS(0, inum.inum, snapshot), flags);
+			     SPOS(0, inum.inum, snapshot),
+			     flags|BTREE_ITER_CACHED);
 	k = bch2_btree_iter_peek_slot(iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -631,20 +629,16 @@ static int bch2_inode_delete_keys(struct btree_trans *trans,
 	return ret;
 }
 
-int bch2_inode_rm(struct bch_fs *c, subvol_inum inum, bool cached)
+int bch2_inode_rm(struct bch_fs *c, subvol_inum inum)
 {
 	struct btree_trans trans;
 	struct btree_iter iter = { NULL };
 	struct bkey_i_inode_generation delete;
 	struct bch_inode_unpacked inode_u;
 	struct bkey_s_c k;
-	unsigned iter_flags = BTREE_ITER_INTENT;
 	u32 snapshot;
 	int ret;
 
-	if (cached && c->opts.inodes_use_key_cache)
-		iter_flags |= BTREE_ITER_CACHED;
-
 	bch2_trans_init(&trans, c, 0, 1024);
 
 	/*
@@ -668,7 +662,8 @@ int bch2_inode_rm(struct bch_fs *c, subvol_inum inum, bool cached)
 		goto err;
 
 	bch2_trans_iter_init(&trans, &iter, BTREE_ID_inodes,
-			     SPOS(0, inum.inum, snapshot), iter_flags);
+			     SPOS(0, inum.inum, snapshot),
+			     BTREE_ITER_INTENT|BTREE_ITER_CACHED);
 	k = bch2_btree_iter_peek_slot(&iter);
 
 	ret = bkey_err(k);

fs/bcachefs/inode.h

@@ -87,7 +87,7 @@ void bch2_inode_init(struct bch_fs *, struct bch_inode_unpacked *,
 int bch2_inode_create(struct btree_trans *, struct btree_iter *,
 		      struct bch_inode_unpacked *, u32, u64);
 
-int bch2_inode_rm(struct bch_fs *, subvol_inum, bool);
+int bch2_inode_rm(struct bch_fs *, subvol_inum);
 
 int bch2_inode_find_by_inum_trans(struct btree_trans *, subvol_inum,
 				  struct bch_inode_unpacked *);

fs/bcachefs/super.c

@@ -770,6 +770,10 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 
 	bch2_opts_apply(&c->opts, opts);
 
+	c->btree_key_cache_btrees |= 1U << BTREE_ID_alloc;
+	if (c->opts.inodes_use_key_cache)
+		c->btree_key_cache_btrees |= 1U << BTREE_ID_inodes;
+
 	c->block_bits		= ilog2(block_sectors(c));
 	c->btree_foreground_merge_threshold = BTREE_FOREGROUND_MERGE_THRESHOLD(c);