bcachefs: Split out struct gc_stripe from struct stripe

We have two radix trees of stripes - one that mirrors some information
from the stripes btree in normal operation, and another that GC uses to
recalculate block usage counts.

The normal one is now only used for finding partially empty stripes in
order to reuse them - the normal stripes radix tree and the GC stripes
radix tree are used significantly differently, so this patch splits them
into separate types.

In an upcoming patch we'll be replacing c->stripes with a btree that
indexes stripes by the order we want to reuse them.

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

1 files changed, 76 insertions, 34 deletions

diff --git a/fs/bcachefs/btree_gc.c b/fs/bcachefs/btree_gc.c
index 6cde4234f5e9..dc4562a1e122 100644
--- a/fs/bcachefs/btree_gc.c
+++ b/fs/bcachefs/btree_gc.c
@@ -597,7 +597,7 @@ static int bch2_check_fix_ptrs(struct bch_fs *c, enum btree_id btree_id,
 		}
 
 		if (p.has_ec) {
-			struct stripe *m = genradix_ptr(&c->stripes[true], p.ec.idx);
+			struct gc_stripe *m = genradix_ptr(&c->gc_stripes, p.ec.idx);
 
 			if (fsck_err_on(!m || !m->alive, c,
 					"pointer to nonexistent stripe %llu\n"
@@ -665,7 +665,7 @@ again:
 			ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
 			bkey_extent_entry_for_each(ptrs, entry) {
 				if (extent_entry_type(entry) == BCH_EXTENT_ENTRY_stripe_ptr) {
-					struct stripe *m = genradix_ptr(&c->stripes[true],
+					struct gc_stripe *m = genradix_ptr(&c->gc_stripes,
 									entry->stripe_ptr.idx);
 					union bch_extent_entry *next_ptr;
 
@@ -1132,7 +1132,8 @@ static void bch2_gc_free(struct bch_fs *c)
 	struct bch_dev *ca;
 	unsigned i;
 
-	genradix_free(&c->stripes[1]);
+	genradix_free(&c->reflink_gc_table);
+	genradix_free(&c->gc_stripes);
 
 	for_each_member_device(ca, c, i) {
 		kvpfree(rcu_dereference_protected(ca->buckets[1], 1),
@@ -1191,35 +1192,6 @@ static int bch2_gc_done(struct bch_fs *c,
 #define copy_fs_field(_f, _msg, ...)					\
 	copy_field(_f, "fs has wrong " _msg, ##__VA_ARGS__)
 
-	if (!metadata_only) {
-		struct genradix_iter iter = genradix_iter_init(&c->stripes[1], 0);
-		struct stripe *dst, *src;
-
-		while ((src = genradix_iter_peek(&iter, &c->stripes[1]))) {
-			dst = genradix_ptr_alloc(&c->stripes[0], iter.pos, GFP_KERNEL);
-
-			if (dst->alive		!= src->alive ||
-			    dst->sectors	!= src->sectors ||
-			    dst->algorithm	!= src->algorithm ||
-			    dst->nr_blocks	!= src->nr_blocks ||
-			    dst->nr_redundant	!= src->nr_redundant) {
-				bch_err(c, "unexpected stripe inconsistency at bch2_gc_done, confused");
-				ret = -EINVAL;
-				goto fsck_err;
-			}
-
-			for (i = 0; i < ARRAY_SIZE(dst->block_sectors); i++)
-				copy_stripe_field(block_sectors[i],
-						  "block_sectors[%u]", i);
-
-			dst->blocks_nonempty = 0;
-			for (i = 0; i < dst->nr_blocks; i++)
-				dst->blocks_nonempty += dst->block_sectors[i] != 0;
-
-			genradix_iter_advance(&iter, &c->stripes[1]);
-		}
-	}
-
 	for (i = 0; i < ARRAY_SIZE(c->usage); i++)
 		bch2_fs_usage_acc_to_base(c, i);
 
@@ -1510,12 +1482,82 @@ static int bch2_gc_reflink_done(struct bch_fs *c, bool initial,
 fsck_err:
 	bch2_trans_iter_exit(&trans, &iter);
 out:
-	genradix_free(&c->reflink_gc_table);
 	c->reflink_gc_nr = 0;
 	bch2_trans_exit(&trans);
 	return ret;
 }
 
+static int bch2_gc_stripes_done_initial_fn(struct btree_trans *trans,
+					   struct bkey_s_c k)
+{
+	struct bch_fs *c = trans->c;
+	struct gc_stripe *m;
+	const struct bch_stripe *s;
+	char buf[200];
+	unsigned i;
+	int ret = 0;
+
+	if (k.k->type != KEY_TYPE_stripe)
+		return 0;
+
+	s = bkey_s_c_to_stripe(k).v;
+
+	m = genradix_ptr(&c->gc_stripes, k.k->p.offset);
+
+	for (i = 0; i < s->nr_blocks; i++)
+		if (stripe_blockcount_get(s, i) != (m ? m->block_sectors[i] : 0))
+			goto inconsistent;
+	return 0;
+inconsistent:
+	if (fsck_err_on(true, c,
+			"stripe has wrong block sector count %u:\n"
+			"  %s\n"
+			"  should be %u", i,
+			(bch2_bkey_val_to_text(&PBUF(buf), c, k), buf),
+			m ? m->block_sectors[i] : 0)) {
+		struct bkey_i_stripe *new;
+
+		new = kmalloc(bkey_bytes(k.k), GFP_KERNEL);
+		if (!new) {
+			ret = -ENOMEM;
+			goto fsck_err;
+		}
+
+		bkey_reassemble(&new->k_i, k);
+
+		for (i = 0; i < new->v.nr_blocks; i++)
+			stripe_blockcount_set(&new->v, i, m ? m->block_sectors[i] : 0);
+
+		ret = bch2_journal_key_insert(c, BTREE_ID_stripes, 0, &new->k_i);
+		if (ret)
+			kfree(new);
+	}
+fsck_err:
+	return ret;
+}
+
+static int bch2_gc_stripes_done(struct bch_fs *c, bool initial,
+				bool metadata_only)
+{
+	struct btree_trans trans;
+	int ret = 0;
+
+	if (metadata_only)
+		return 0;
+
+	bch2_trans_init(&trans, c, 0, 0);
+
+	if (initial) {
+		ret = bch2_btree_and_journal_walk(&trans, BTREE_ID_stripes,
+				bch2_gc_stripes_done_initial_fn);
+	} else {
+		BUG();
+	}
+
+	bch2_trans_exit(&trans);
+	return ret;
+}
+
 static int bch2_gc_reflink_start_initial_fn(struct btree_trans *trans,
 					    struct bkey_s_c k)
 {
@@ -1551,7 +1593,6 @@ static int bch2_gc_reflink_start(struct bch_fs *c, bool initial,
 		return 0;
 
 	bch2_trans_init(&trans, c, 0, 0);
-	genradix_free(&c->reflink_gc_table);
 	c->reflink_gc_nr = 0;
 
 	if (initial) {
@@ -1685,6 +1726,7 @@ out:
 
 		percpu_down_write(&c->mark_lock);
 		ret   = bch2_gc_reflink_done(c, initial, metadata_only) ?:
+			bch2_gc_stripes_done(c, initial, metadata_only) ?:
 			bch2_gc_done(c, initial, metadata_only);
 
 		bch2_journal_unblock(&c->journal);