bcachefs: don't do initial gc if have alloc info feature

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

fs/bcachefs/bcachefs.h

@@ -568,6 +568,7 @@ struct bch_fs {
 		u32		time_base_hi;
 		u32		time_precision;
 		u64		features;
+		u64		compat;
 	}			sb;
 
 	struct bch_sb_handle	disk_sb;

fs/bcachefs/bcachefs_format.h

@@ -1279,6 +1279,10 @@ enum bch_sb_features {
 	BCH_FEATURE_NR,
 };
 
+enum bch_sb_compat {
+	BCH_COMPAT_FEAT_ALLOC_INFO	= 0,
+};
+
 /* options: */
 
 #define BCH_REPLICAS_MAX		4U

fs/bcachefs/btree_gc.c

@@ -577,7 +577,8 @@ static void bch2_gc_done(struct bch_fs *c, bool initial)
 
 	percpu_down_write(&c->mark_lock);
 
-	if (initial) {
+	if (initial &&
+	    !(c->sb.compat & (1ULL << BCH_COMPAT_FEAT_ALLOC_INFO))) {
 		bch2_gc_done_nocheck(c);
 		goto out;
 	}
@@ -819,9 +820,6 @@ int bch2_gc(struct bch_fs *c, struct list_head *journal, bool initial)
 	bch2_gc_free(c);
 	up_write(&c->gc_lock);
 
-	if (!ret && initial)
-		set_bit(BCH_FS_INITIAL_GC_DONE, &c->flags);
-
 	trace_gc_end(c);
 	bch2_time_stats_update(&c->times[BCH_TIME_btree_gc], start_time);
 

fs/bcachefs/recovery.c

@@ -300,14 +300,18 @@ int bch2_fs_recovery(struct bch_fs *c)
 
 	set_bit(BCH_FS_ALLOC_READ_DONE, &c->flags);
 
-	bch_verbose(c, "starting mark and sweep:");
-	err = "error in recovery";
-	ret = bch2_gc(c, &journal, true);
-	if (ret)
-		goto err;
-	bch_verbose(c, "mark and sweep done");
+	if (!(c->sb.compat & (1ULL << BCH_COMPAT_FEAT_ALLOC_INFO)) ||
+	    c->opts.fsck) {
+		bch_verbose(c, "starting mark and sweep:");
+		err = "error in recovery";
+		ret = bch2_gc(c, &journal, true);
+		if (ret)
+			goto err;
+		bch_verbose(c, "mark and sweep done");
+	}
 
 	clear_bit(BCH_FS_REBUILD_REPLICAS, &c->flags);
+	set_bit(BCH_FS_INITIAL_GC_DONE, &c->flags);
 
 	/*
 	 * Skip past versions that might have possibly been used (as nonces),
@@ -411,6 +415,8 @@ int bch2_fs_initialize(struct bch_fs *c)
 	if (ret)
 		goto err;
 
+	set_bit(BCH_FS_INITIAL_GC_DONE, &c->flags);
+
 	err = "unable to allocate journal buckets";
 	for_each_online_member(ca, c, i)
 		if (bch2_dev_journal_alloc(ca)) {

fs/bcachefs/super-io.c

@@ -371,6 +371,7 @@ static void bch2_sb_update(struct bch_fs *c)
 	c->sb.time_base_hi	= le32_to_cpu(src->time_base_hi);
 	c->sb.time_precision	= le32_to_cpu(src->time_precision);
 	c->sb.features		= le64_to_cpu(src->features[0]);
+	c->sb.compat		= le64_to_cpu(src->compat[0]);
 
 	for_each_member_device(ca, c, i)
 		ca->mi = bch2_mi_to_cpu(mi->members + i);
@@ -888,8 +889,10 @@ void bch2_sb_clean_renumber(struct bch_sb_field_clean *clean, int write)
 static void bch2_fs_mark_dirty(struct bch_fs *c)
 {
 	mutex_lock(&c->sb_lock);
-	if (BCH_SB_CLEAN(c->disk_sb.sb)) {
+	if (BCH_SB_CLEAN(c->disk_sb.sb) ||
+	    (c->disk_sb.sb->compat[0] & (1ULL << BCH_COMPAT_FEAT_ALLOC_INFO))) {
 		SET_BCH_SB_CLEAN(c->disk_sb.sb, false);
+		c->disk_sb.sb->compat[0] &= ~(1ULL << BCH_COMPAT_FEAT_ALLOC_INFO);
 		bch2_write_super(c);
 	}
 	mutex_unlock(&c->sb_lock);
@@ -1011,6 +1014,8 @@ void bch2_fs_mark_clean(struct bch_fs *c, bool clean)
 
 	SET_BCH_SB_CLEAN(c->disk_sb.sb, true);
 
+	c->disk_sb.sb->compat[0] |= 1ULL << BCH_COMPAT_FEAT_ALLOC_INFO;
+
 	u64s = sizeof(*sb_clean) / sizeof(u64) + c->journal.entry_u64s_reserved;
 
 	sb_clean = bch2_sb_resize_clean(&c->disk_sb, u64s);