bcachefs: BCH_WATERMARK_reclaim

Add another watermark for journal reclaim - this is needed for the next
patches, that unify BCH_WATERMARK with JOURNAL_WATERMARK.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/alloc_foreground.c

@@ -191,11 +191,13 @@ long bch2_bucket_alloc_new_fs(struct bch_dev *ca)
 static inline unsigned open_buckets_reserved(enum bch_watermark watermark)
 {
 	switch (watermark) {
+	case BCH_WATERMARK_reclaim:
+		return 0;
 	case BCH_WATERMARK_btree:
 	case BCH_WATERMARK_btree_copygc:
-		return 0;
-	case BCH_WATERMARK_copygc:
 		return OPEN_BUCKETS_COUNT / 4;
+	case BCH_WATERMARK_copygc:
+		return OPEN_BUCKETS_COUNT / 3;
 	default:
 		return OPEN_BUCKETS_COUNT / 2;
 	}

fs/bcachefs/alloc_types.h

@@ -17,6 +17,7 @@ struct bucket_alloc_state {
 };
 
 #define BCH_WATERMARKS()		\
+	x(reclaim)			\
 	x(btree_copygc)			\
 	x(btree)			\
 	x(copygc)			\

fs/bcachefs/buckets.h

@@ -170,6 +170,7 @@ static inline u64 bch2_dev_buckets_reserved(struct bch_dev *ca, enum bch_waterma
 		reserved += ca->nr_btree_reserve;
 		fallthrough;
 	case BCH_WATERMARK_btree_copygc:
+	case BCH_WATERMARK_reclaim:
 		break;
 	}