bcachefs: btree_gc can now handle unknown btrees

Compatibility fix - we no longer have a separate table for which order
gc walks btrees in, and special case the stripes btree directly.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/bcachefs.h

@@ -457,6 +457,7 @@ enum bch_time_stats {
 };
 
 #include "alloc_types.h"
+#include "btree_gc_types.h"
 #include "btree_types.h"
 #include "btree_node_scan_types.h"
 #include "btree_write_buffer_types.h"
@@ -488,49 +489,6 @@ enum bch_time_stats {
 
 struct btree;
 
-enum gc_phase {
-	GC_PHASE_NOT_RUNNING,
-	GC_PHASE_START,
-	GC_PHASE_SB,
-
-	GC_PHASE_BTREE_stripes,
-	GC_PHASE_BTREE_extents,
-	GC_PHASE_BTREE_inodes,
-	GC_PHASE_BTREE_dirents,
-	GC_PHASE_BTREE_xattrs,
-	GC_PHASE_BTREE_alloc,
-	GC_PHASE_BTREE_quotas,
-	GC_PHASE_BTREE_reflink,
-	GC_PHASE_BTREE_subvolumes,
-	GC_PHASE_BTREE_snapshots,
-	GC_PHASE_BTREE_lru,
-	GC_PHASE_BTREE_freespace,
-	GC_PHASE_BTREE_need_discard,
-	GC_PHASE_BTREE_backpointers,
-	GC_PHASE_BTREE_bucket_gens,
-	GC_PHASE_BTREE_snapshot_trees,
-	GC_PHASE_BTREE_deleted_inodes,
-	GC_PHASE_BTREE_logged_ops,
-	GC_PHASE_BTREE_rebalance_work,
-	GC_PHASE_BTREE_subvolume_children,
-
-	GC_PHASE_PENDING_DELETE,
-};
-
-struct gc_pos {
-	enum gc_phase		phase;
-	u16			level;
-	struct bpos		pos;
-};
-
-struct reflink_gc {
-	u64		offset;
-	u32		size;
-	u32		refcount;
-};
-
-typedef GENRADIX(struct reflink_gc) reflink_gc_table;
-
 struct io_count {
 	u64			sectors[2][BCH_DATA_NR];
 };

fs/bcachefs/btree_gc.c

@@ -673,8 +673,7 @@ static int bch2_gc_btree(struct btree_trans *trans, enum btree_id btree, bool in
 
 static inline int btree_id_gc_phase_cmp(enum btree_id l, enum btree_id r)
 {
-	return  (int) btree_id_to_gc_phase(l) -
-		(int) btree_id_to_gc_phase(r);
+	return cmp_int(gc_btree_order(l), gc_btree_order(r));
 }
 
 static int bch2_gc_btrees(struct bch_fs *c)
@@ -711,7 +710,7 @@ static int bch2_gc_btrees(struct bch_fs *c)
 static int bch2_mark_superblocks(struct bch_fs *c)
 {
 	mutex_lock(&c->sb_lock);
-	gc_pos_set(c, gc_phase(GC_PHASE_SB));
+	gc_pos_set(c, gc_phase(GC_PHASE_sb));
 
 	int ret = bch2_trans_mark_dev_sbs_flags(c, BTREE_TRIGGER_gc);
 	mutex_unlock(&c->sb_lock);
@@ -1209,7 +1208,7 @@ int bch2_check_allocations(struct bch_fs *c)
 	if (ret)
 		goto out;
 
-	gc_pos_set(c, gc_phase(GC_PHASE_START));
+	gc_pos_set(c, gc_phase(GC_PHASE_start));
 
 	ret = bch2_mark_superblocks(c);
 	BUG_ON(ret);
@@ -1231,7 +1230,7 @@ int bch2_check_allocations(struct bch_fs *c)
 
 	percpu_down_write(&c->mark_lock);
 	/* Indicates that gc is no longer in progress: */
-	__gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING));
+	__gc_pos_set(c, gc_phase(GC_PHASE_not_running));
 
 	bch2_gc_free(c);
 	percpu_up_write(&c->mark_lock);

fs/bcachefs/btree_gc.h

@@ -3,6 +3,7 @@
 #define _BCACHEFS_BTREE_GC_H
 
 #include "bkey.h"
+#include "btree_gc_types.h"
 #include "btree_types.h"
 
 int bch2_check_topology(struct bch_fs *);
@@ -32,36 +33,15 @@ int bch2_check_allocations(struct bch_fs *);
 /* Position of (the start of) a gc phase: */
 static inline struct gc_pos gc_phase(enum gc_phase phase)
 {
-	return (struct gc_pos) {
-		.phase	= phase,
-		.level	= 0,
-		.pos	= POS_MIN,
-	};
-}
-
-static inline int gc_pos_cmp(struct gc_pos l, struct gc_pos r)
-{
-	return   cmp_int(l.phase, r.phase) ?:
-		-cmp_int(l.level, r.level) ?:
-		 bpos_cmp(l.pos, r.pos);
-}
-
-static inline enum gc_phase btree_id_to_gc_phase(enum btree_id id)
-{
-	switch (id) {
-#define x(name, v, ...) case BTREE_ID_##name: return GC_PHASE_BTREE_##name;
-	BCH_BTREE_IDS()
-#undef x
-	default:
-		BUG();
-	}
+	return (struct gc_pos) { .phase	= phase, };
 }
 
 static inline struct gc_pos gc_pos_btree(enum btree_id btree, unsigned level,
 					 struct bpos pos)
 {
 	return (struct gc_pos) {
-		.phase	= btree_id_to_gc_phase(btree),
+		.phase	= GC_PHASE_btree,
+		.btree	= btree,
 		.level	= level,
 		.pos	= pos,
 	};
@@ -76,6 +56,22 @@ static inline struct gc_pos gc_pos_btree_node(struct btree *b)
 	return gc_pos_btree(b->c.btree_id, b->c.level, b->key.k.p);
 }
 
+static inline int gc_btree_order(enum btree_id btree)
+{
+	if (btree == BTREE_ID_stripes)
+		return -1;
+	return btree;
+}
+
+static inline int gc_pos_cmp(struct gc_pos l, struct gc_pos r)
+{
+	return   cmp_int(l.phase, r.phase) ?:
+		 cmp_int(gc_btree_order(l.btree),
+			 gc_btree_order(r.btree)) ?:
+		-cmp_int(l.level, r.level) ?:
+		 bpos_cmp(l.pos, r.pos);
+}
+
 static inline bool gc_visited(struct bch_fs *c, struct gc_pos pos)
 {
 	unsigned seq;

fs/bcachefs/btree_gc_types.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_BTREE_GC_TYPES_H
+#define _BCACHEFS_BTREE_GC_TYPES_H
+
+#include <linux/generic-radix-tree.h>
+
+enum gc_phase {
+	GC_PHASE_not_running,
+	GC_PHASE_start,
+	GC_PHASE_sb,
+	GC_PHASE_btree,
+};
+
+struct gc_pos {
+	enum gc_phase		phase:8;
+	enum btree_id		btree:8;
+	u16			level;
+	struct bpos		pos;
+};
+
+struct reflink_gc {
+	u64		offset;
+	u32		size;
+	u32		refcount;
+};
+
+typedef GENRADIX(struct reflink_gc) reflink_gc_table;
+
+#endif /* _BCACHEFS_BTREE_GC_TYPES_H */

fs/bcachefs/ec.c

@@ -908,7 +908,7 @@ static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp)
 	if (!genradix_ptr_alloc(&c->stripes, idx, gfp))
 		return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
 
-	if (c->gc_pos.phase != GC_PHASE_NOT_RUNNING &&
+	if (c->gc_pos.phase != GC_PHASE_not_running &&
 	    !genradix_ptr_alloc(&c->gc_stripes, idx, gfp))
 		return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;