Update bcachefs sources to cdf89ca564 bcachefs: Fix fsck path for refink pointers

12 files changed, 159 insertions, 154 deletions

diff --git a/libbcachefs/alloc_background.c b/libbcachefs/alloc_background.c
index d35bd849..93fa9bf9 100644
--- a/libbcachefs/alloc_background.c
+++ b/libbcachefs/alloc_background.c
@@ -367,8 +367,6 @@ int bch2_alloc_write(struct bch_fs *c, unsigned flags)
 			POS(ca->dev_idx, ca->mi.first_bucket));
 
 		while (iter.pos.offset < ca->mi.nbuckets) {
-			bch2_trans_cond_resched(&trans);
-
 			ret = bch2_alloc_write_key(&trans, &iter, flags);
 			if (ret) {
 				percpu_ref_put(&ca->ref);
diff --git a/libbcachefs/btree_gc.c b/libbcachefs/btree_gc.c
index dcbde49f..54b3d0d9 100644
--- a/libbcachefs/btree_gc.c
+++ b/libbcachefs/btree_gc.c
@@ -817,19 +817,15 @@ static int bch2_gc_btree(struct bch_fs *c, enum btree_id btree_id,
 
 		if (!initial) {
 			if (max_stale > 64)
-				bch2_btree_node_rewrite(&trans, &iter,
-						b->data->keys.seq,
+				bch2_btree_node_rewrite(&trans, &iter, b,
 						BTREE_INSERT_NOWAIT|
 						BTREE_INSERT_GC_LOCK_HELD);
 			else if (!bch2_btree_gc_rewrite_disabled &&
 				 (bch2_btree_gc_always_rewrite || max_stale > 16))
 				bch2_btree_node_rewrite(&trans, &iter,
-						b->data->keys.seq,
-						BTREE_INSERT_NOWAIT|
+						b, BTREE_INSERT_NOWAIT|
 						BTREE_INSERT_GC_LOCK_HELD);
 		}
-
-		bch2_trans_cond_resched(&trans);
 	}
 	bch2_trans_iter_exit(&trans, &iter);
 
diff --git a/libbcachefs/btree_iter.c b/libbcachefs/btree_iter.c
index 47c10886..6ee3366e 100644
--- a/libbcachefs/btree_iter.c
+++ b/libbcachefs/btree_iter.c
@@ -27,6 +27,21 @@ static inline void btree_path_list_add(struct btree_trans *, struct btree_path *
 
 static struct btree_path *btree_path_alloc(struct btree_trans *, struct btree_path *);
 
+/*
+ * Unlocks before scheduling
+ * Note: does not revalidate iterator
+ */
+static inline int bch2_trans_cond_resched(struct btree_trans *trans)
+{
+	if (need_resched() || race_fault()) {
+		bch2_trans_unlock(trans);
+		schedule();
+		return bch2_trans_relock(trans) ? 0 : -EINTR;
+	} else {
+		return 0;
+	}
+}
+
 static inline int __btree_path_cmp(const struct btree_path *l,
 				   enum btree_id	r_btree_id,
 				   bool			r_cached,
@@ -1444,6 +1459,11 @@ static int btree_path_traverse_one(struct btree_trans *trans,
 	unsigned depth_want = path->level;
 	int ret = 0;
 
+	if (unlikely(trans->restarted)) {
+		ret = -EINTR;
+		goto out;
+	}
+
 	/*
 	 * Ensure we obey path->should_be_locked: if it's set, we can't unlock
 	 * and re-traverse the path without a transaction restart:
@@ -1911,30 +1931,41 @@ struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
 	struct btree_trans *trans = iter->trans;
 	struct btree_path *path = iter->path;
 	struct btree *b = NULL;
+	unsigned l;
 	int ret;
 
+	BUG_ON(trans->restarted);
 	EBUG_ON(iter->path->cached);
 	bch2_btree_iter_verify(iter);
 
-	/* already got to end? */
+	/* already at end? */
 	if (!btree_path_node(path, path->level))
-		goto out;
+		return NULL;
 
-	btree_node_unlock(path, path->level);
-	path->l[path->level].b = BTREE_ITER_NO_NODE_UP;
-	path->level++;
+	/* got to end? */
+	if (!btree_path_node(path, path->level + 1)) {
+		btree_node_unlock(path, path->level);
+		path->l[path->level].b = BTREE_ITER_NO_NODE_UP;
+		path->level++;
+		return NULL;
+	}
 
-	btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
-	ret = bch2_btree_path_traverse(trans, path, iter->flags);
-	if (ret)
+	if (!bch2_btree_node_relock(trans, path, path->level + 1)) {
+		__bch2_btree_path_unlock(path);
+		path->l[path->level].b = BTREE_ITER_NO_NODE_GET_LOCKS;
+		path->l[path->level + 1].b = BTREE_ITER_NO_NODE_GET_LOCKS;
+		btree_trans_restart(trans);
+		ret = -EINTR;
 		goto err;
+	}
 
-	/* got to end? */
-	b = btree_path_node(path, path->level);
-	if (!b)
-		goto out;
+	b = btree_path_node(path, path->level + 1);
 
-	if (bpos_cmp(iter->pos, b->key.k.p) < 0) {
+	if (!bpos_cmp(iter->pos, b->key.k.p)) {
+		btree_node_unlock(path, path->level);
+		path->l[path->level].b = BTREE_ITER_NO_NODE_UP;
+		path->level++;
+	} else {
 		/*
 		 * Haven't gotten to the end of the parent node: go back down to
 		 * the next child node
@@ -1943,10 +1974,12 @@ struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
 			btree_path_set_pos(trans, path, bpos_successor(iter->pos),
 					   iter->flags & BTREE_ITER_INTENT);
 
-		/* Unlock to avoid screwing up our lock invariants: */
-		btree_node_unlock(path, path->level);
-
 		path->level = iter->min_depth;
+
+		for (l = path->level + 1; l < BTREE_MAX_DEPTH; l++)
+			if (btree_lock_want(path, l) == BTREE_NODE_UNLOCKED)
+				btree_node_unlock(path, l);
+
 		btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
 		bch2_btree_iter_verify(iter);
 
diff --git a/libbcachefs/btree_iter.h b/libbcachefs/btree_iter.h
index eaf432aa..876bf42c 100644
--- a/libbcachefs/btree_iter.h
+++ b/libbcachefs/btree_iter.h
@@ -243,21 +243,6 @@ static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 sna
 	bch2_btree_iter_set_pos(iter, pos);
 }
 
-/*
- * Unlocks before scheduling
- * Note: does not revalidate iterator
- */
-static inline int bch2_trans_cond_resched(struct btree_trans *trans)
-{
-	if (need_resched() || race_fault()) {
-		bch2_trans_unlock(trans);
-		schedule();
-		return bch2_trans_relock(trans) ? 0 : -EINTR;
-	} else {
-		return 0;
-	}
-}
-
 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 void bch2_trans_iter_init(struct btree_trans *, struct btree_iter *,
 			  unsigned, struct bpos, unsigned);
diff --git a/libbcachefs/btree_update.h b/libbcachefs/btree_update.h
index 155643da..0268dd74 100644
--- a/libbcachefs/btree_update.h
+++ b/libbcachefs/btree_update.h
@@ -66,7 +66,7 @@ int bch2_btree_delete_range(struct bch_fs *, enum btree_id,
 			    struct bpos, struct bpos, u64 *);
 
 int bch2_btree_node_rewrite(struct btree_trans *, struct btree_iter *,
-			    __le64, unsigned);
+			    struct btree *, unsigned);
 void bch2_btree_node_rewrite_async(struct bch_fs *, struct btree *);
 int bch2_btree_node_update_key(struct btree_trans *, struct btree_iter *,
 			       struct btree *, struct bkey_i *, bool);
diff --git a/libbcachefs/btree_update_interior.c b/libbcachefs/btree_update_interior.c
index 591a2fed..61c7757b 100644
--- a/libbcachefs/btree_update_interior.c
+++ b/libbcachefs/btree_update_interior.c
@@ -1722,26 +1722,15 @@ err:
  */
 int bch2_btree_node_rewrite(struct btree_trans *trans,
 			    struct btree_iter *iter,
-			    __le64 seq, unsigned flags)
+			    struct btree *b,
+			    unsigned flags)
 {
 	struct bch_fs *c = trans->c;
-	struct btree *b, *n, *parent;
+	struct btree *n, *parent;
 	struct btree_update *as;
 	int ret;
 
 	flags |= BTREE_INSERT_NOFAIL;
-retry:
-	ret = bch2_btree_iter_traverse(iter);
-	if (ret)
-		goto out;
-
-	b = bch2_btree_iter_peek_node(iter);
-	ret = PTR_ERR_OR_ZERO(b);
-	if (ret)
-		goto out;
-
-	if (!b || b->data->keys.seq != seq)
-		goto out;
 
 	parent = btree_node_parent(iter->path, b);
 	as = bch2_btree_update_start(trans, iter->path, b->c.level,
@@ -1750,8 +1739,6 @@ retry:
 		 : 0) + 1,
 		flags);
 	ret = PTR_ERR_OR_ZERO(as);
-	if (ret == -EINTR)
-		goto retry;
 	if (ret) {
 		trace_btree_gc_rewrite_node_fail(c, b);
 		goto out;
@@ -1799,20 +1786,38 @@ struct async_btree_rewrite {
 	__le64			seq;
 };
 
+static int async_btree_node_rewrite_trans(struct btree_trans *trans,
+					  struct async_btree_rewrite *a)
+{
+	struct btree_iter iter;
+	struct btree *b;
+	int ret;
+
+	bch2_trans_node_iter_init(trans, &iter, a->btree_id, a->pos,
+				  BTREE_MAX_DEPTH, a->level, 0);
+	b = bch2_btree_iter_peek_node(&iter);
+	ret = PTR_ERR_OR_ZERO(b);
+	if (ret)
+		goto out;
+
+	if (!b || b->data->keys.seq != a->seq)
+		goto out;
+
+	ret = bch2_btree_node_rewrite(trans, &iter, b, 0);
+out :
+	bch2_trans_iter_exit(trans, &iter);
+
+	return ret;
+}
+
 void async_btree_node_rewrite_work(struct work_struct *work)
 {
 	struct async_btree_rewrite *a =
 		container_of(work, struct async_btree_rewrite, work);
 	struct bch_fs *c = a->c;
-	struct btree_trans trans;
-	struct btree_iter iter;
 
-	bch2_trans_init(&trans, c, 0, 0);
-	bch2_trans_node_iter_init(&trans, &iter, a->btree_id, a->pos,
-					BTREE_MAX_DEPTH, a->level, 0);
-	bch2_btree_node_rewrite(&trans, &iter, a->seq, 0);
-	bch2_trans_iter_exit(&trans, &iter);
-	bch2_trans_exit(&trans);
+	bch2_trans_do(c, NULL, NULL, 0,
+		      async_btree_node_rewrite_trans(&trans, a));
 	percpu_ref_put(&c->writes);
 	kfree(a);
 }
diff --git a/libbcachefs/btree_update_leaf.c b/libbcachefs/btree_update_leaf.c
index 762a9773..c4054667 100644
--- a/libbcachefs/btree_update_leaf.c
+++ b/libbcachefs/btree_update_leaf.c
@@ -1160,13 +1160,13 @@ next:
 	if (bch2_bkey_maybe_mergable(&insert->k, k.k)) {
 		ret = check_pos_snapshot_overwritten(trans, btree_id, insert->k.p);
 		if (ret < 0)
-			goto out;
+			goto err;
 		if (ret)
 			goto nomerge2;
 
 		ret = check_pos_snapshot_overwritten(trans, btree_id, k.k->p);
 		if (ret < 0)
-			goto out;
+			goto err;
 		if (ret)
 			goto nomerge2;
 
@@ -1405,8 +1405,6 @@ retry:
 					BTREE_INSERT_NOFAIL);
 		if (ret)
 			break;
-
-		bch2_trans_cond_resched(trans);
 	}
 
 	if (ret == -EINTR) {
diff --git a/libbcachefs/buckets.c b/libbcachefs/buckets.c
index 97151ec8..45215d0a 100644
--- a/libbcachefs/buckets.c
+++ b/libbcachefs/buckets.c
@@ -1108,61 +1108,47 @@ static int bch2_mark_reservation(struct bch_fs *c,
 }
 
 static s64 __bch2_mark_reflink_p(struct bch_fs *c, struct bkey_s_c_reflink_p p,
-				 u64 idx, unsigned flags, size_t *r_idx)
+				 u64 *idx, unsigned flags, size_t r_idx)
 {
 	struct reflink_gc *r;
 	int add = !(flags & BTREE_TRIGGER_OVERWRITE) ? 1 : -1;
 	s64 ret = 0;
 
-	while (*r_idx < c->reflink_gc_nr) {
-		r = genradix_ptr(&c->reflink_gc_table, *r_idx);
-		BUG_ON(!r);
-
-		if (idx < r->offset)
-			break;
-		(*r_idx)++;
-	}
+	if (r_idx >= c->reflink_gc_nr)
+		goto not_found;
 
-	if (*r_idx >= c->reflink_gc_nr ||
-	    idx < r->offset - r->size) {
-		ret = p.k->size;
+	r = genradix_ptr(&c->reflink_gc_table, r_idx);
+	if (*idx < r->offset - r->size)
 		goto not_found;
-	}
 
 	BUG_ON((s64) r->refcount + add < 0);
 
 	r->refcount += add;
-	return r->offset - idx;
+	*idx = r->offset;
+	return 0;
 not_found:
-	if ((flags & BTREE_TRIGGER_GC) &&
-	    (flags & BTREE_TRIGGER_NOATOMIC)) {
-		/*
-		 * XXX: we're replacing the entire reflink pointer with an error
-		 * key, we should just be replacing the part that was missing:
-		 */
-		if (fsck_err(c, "%llu:%llu len %u points to nonexistent indirect extent %llu",
-			     p.k->p.inode, p.k->p.offset, p.k->size, idx)) {
-			struct bkey_i_error *new;
-
-			new = kmalloc(sizeof(*new), GFP_KERNEL);
-			if (!new) {
-				bch_err(c, "%s: error allocating new key", __func__);
-				return -ENOMEM;
-			}
+	*idx = U64_MAX;
+	ret = -EIO;
 
-			bkey_init(&new->k);
-			new->k.type	= KEY_TYPE_error;
-			new->k.p	= p.k->p;
-			new->k.size	= p.k->size;
-			ret = bch2_journal_key_insert(c, BTREE_ID_extents, 0, &new->k_i);
+	/*
+	 * XXX: we're replacing the entire reflink pointer with an error
+	 * key, we should just be replacing the part that was missing:
+	 */
+	if (fsck_err(c, "%llu:%llu len %u points to nonexistent indirect extent %llu",
+		     p.k->p.inode, p.k->p.offset, p.k->size, *idx)) {
+		struct bkey_i_error *new;
 
+		new = kmalloc(sizeof(*new), GFP_KERNEL);
+		if (!new) {
+			bch_err(c, "%s: error allocating new key", __func__);
+			return -ENOMEM;
 		}
-	} else {
-		bch2_fs_inconsistent(c,
-				     "%llu:%llu len %u points to nonexistent indirect extent %llu",
-				     p.k->p.inode, p.k->p.offset, p.k->size, idx);
-		bch2_inconsistent_error(c);
-		ret = -EIO;
+
+		bkey_init(&new->k);
+		new->k.type	= KEY_TYPE_error;
+		new->k.p	= p.k->p;
+		new->k.size	= p.k->size;
+		ret = bch2_journal_key_insert(c, BTREE_ID_extents, 0, &new->k_i);
 	}
 fsck_err:
 	return ret;
@@ -1177,10 +1163,9 @@ static int bch2_mark_reflink_p(struct bch_fs *c,
 	struct reflink_gc *ref;
 	size_t l, r, m;
 	u64 idx = le64_to_cpu(p.v->idx) - le32_to_cpu(p.v->front_pad);
-	u64 sectors = (u64) le32_to_cpu(p.v->front_pad) +
-			    le32_to_cpu(p.v->back_pad) +
-			    p.k->size;
-	s64 ret = 0;
+	u64 end_idx = le64_to_cpu(p.v->idx) + p.k->size +
+		le32_to_cpu(p.v->back_pad);
+	int ret = 0;
 
 	BUG_ON((flags & (BTREE_TRIGGER_INSERT|BTREE_TRIGGER_OVERWRITE)) ==
 	       (BTREE_TRIGGER_INSERT|BTREE_TRIGGER_OVERWRITE));
@@ -1197,17 +1182,10 @@ static int bch2_mark_reflink_p(struct bch_fs *c,
 			r = m;
 	}
 
-	while (sectors) {
-		ret = __bch2_mark_reflink_p(c, p, idx, flags, &l);
-		if (ret <= 0)
-			return ret;
+	while (idx < end_idx && !ret)
+		ret = __bch2_mark_reflink_p(c, p, &idx, flags, l++);
 
-		ret = min_t(s64, ret, sectors);
-		idx	+= ret;
-		sectors	-= ret;
-	}
-
-	return 0;
+	return ret;
 }
 
 static int bch2_mark_key_locked(struct bch_fs *c,
@@ -1725,7 +1703,7 @@ static int bch2_trans_mark_reservation(struct btree_trans *trans,
 
 static int __bch2_trans_mark_reflink_p(struct btree_trans *trans,
 			struct bkey_s_c_reflink_p p,
-			u64 idx, unsigned flags)
+			u64 *idx, unsigned flags)
 {
 	struct bch_fs *c = trans->c;
 	struct btree_iter iter;
@@ -1733,9 +1711,9 @@ static int __bch2_trans_mark_reflink_p(struct btree_trans *trans,
 	struct bkey_i *n;
 	__le64 *refcount;
 	int add = !(flags & BTREE_TRIGGER_OVERWRITE) ? 1 : -1;
-	s64 ret;
+	int ret;
 
-	bch2_trans_iter_init(trans, &iter, BTREE_ID_reflink, POS(0, idx),
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_reflink, POS(0, *idx),
 			     BTREE_ITER_INTENT|
 			     BTREE_ITER_WITH_UPDATES);
 	k = bch2_btree_iter_peek_slot(&iter);
@@ -1754,7 +1732,7 @@ static int __bch2_trans_mark_reflink_p(struct btree_trans *trans,
 	if (!refcount) {
 		bch2_fs_inconsistent(c,
 			"%llu:%llu len %u points to nonexistent indirect extent %llu",
-			p.k->p.inode, p.k->p.offset, p.k->size, idx);
+			p.k->p.inode, p.k->p.offset, p.k->size, *idx);
 		ret = -EIO;
 		goto err;
 	}
@@ -1762,7 +1740,7 @@ static int __bch2_trans_mark_reflink_p(struct btree_trans *trans,
 	if (!*refcount && (flags & BTREE_TRIGGER_OVERWRITE)) {
 		bch2_fs_inconsistent(c,
 			"%llu:%llu len %u idx %llu indirect extent refcount underflow",
-			p.k->p.inode, p.k->p.offset, p.k->size, idx);
+			p.k->p.inode, p.k->p.offset, p.k->size, *idx);
 		ret = -EIO;
 		goto err;
 	}
@@ -1794,7 +1772,7 @@ static int __bch2_trans_mark_reflink_p(struct btree_trans *trans,
 	if (ret)
 		goto err;
 
-	ret = k.k->p.offset - idx;
+	*idx = k.k->p.offset;
 err:
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
@@ -1804,8 +1782,8 @@ static int bch2_trans_mark_reflink_p(struct btree_trans *trans,
 				     struct bkey_s_c k, unsigned flags)
 {
 	struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
-	u64 idx, sectors;
-	s64 ret = 0;
+	u64 idx, end_idx;
+	int ret = 0;
 
 	if (flags & BTREE_TRIGGER_INSERT) {
 		struct bch_reflink_p *v = (struct bch_reflink_p *) p.v;
@@ -1813,22 +1791,14 @@ static int bch2_trans_mark_reflink_p(struct btree_trans *trans,
 		v->front_pad = v->back_pad = 0;
 	}
 
-	idx = le64_to_cpu(p.v->idx) - le32_to_cpu(p.v->front_pad);
-	sectors = (u64) le32_to_cpu(p.v->front_pad) +
-			le32_to_cpu(p.v->back_pad) +
-			p.k->size;
-
-	while (sectors) {
-		ret = __bch2_trans_mark_reflink_p(trans, p, idx, flags);
-		if (ret < 0)
-			return ret;
+	idx	= le64_to_cpu(p.v->idx) - le32_to_cpu(p.v->front_pad);
+	end_idx = le64_to_cpu(p.v->idx) + p.k->size +
+		le32_to_cpu(p.v->back_pad);
 
-		ret = min_t(s64, ret, sectors);
-		idx	+= ret;
-		sectors	-= ret;
-	}
+	while (idx < end_idx && !ret)
+		ret = __bch2_trans_mark_reflink_p(trans, p, &idx, flags);
 
-	return 0;
+	return ret;
 }
 
 int bch2_trans_mark_key(struct btree_trans *trans, struct bkey_s_c old,
diff --git a/libbcachefs/dirent.c b/libbcachefs/dirent.c
index 2ab9cbaf..6be3ec4e 100644
--- a/libbcachefs/dirent.c
+++ b/libbcachefs/dirent.c
@@ -529,6 +529,15 @@ retry:
 			      vfs_d_type(dirent.v->d_type)))
 			break;
 		ctx->pos = dirent.k->p.offset + 1;
+
+		/*
+		 * read_target looks up subvolumes, we can overflow paths if the
+		 * directory has many subvolumes in it
+		 */
+		if (hweight64(trans.paths_allocated) > BTREE_ITER_MAX / 2) {
+			ret = -EINTR;
+			break;
+		}
 	}
 	bch2_trans_iter_exit(&trans, &iter);
 err:
diff --git a/libbcachefs/fsck.c b/libbcachefs/fsck.c
index 58d42734..197b9079 100644
--- a/libbcachefs/fsck.c
+++ b/libbcachefs/fsck.c
@@ -2116,8 +2116,6 @@ static int check_nlinks_walk_dirents(struct bch_fs *c, struct nlink_table *links
 					 d.k->p.snapshot);
 			break;
 		}
-
-		bch2_trans_cond_resched(&trans);
 	}
 	bch2_trans_iter_exit(&trans, &iter);
 
diff --git a/libbcachefs/move.c b/libbcachefs/move.c
index 20396820..fae26009 100644
--- a/libbcachefs/move.c
+++ b/libbcachefs/move.c
@@ -768,7 +768,6 @@ next:
 			     &stats->sectors_seen);
 next_nondata:
 		bch2_btree_iter_advance(&iter);
-		bch2_trans_cond_resched(&trans);
 	}
 out:
 
@@ -911,10 +910,12 @@ retry:
 				BUG();
 			}
 
-			ret = bch2_btree_node_rewrite(&trans, &iter,
-					b->data->keys.seq, 0) ?: ret;
+			ret = bch2_btree_node_rewrite(&trans, &iter, b, 0) ?: ret;
+			if (ret == -EINTR)
+				continue;
+			if (ret)
+				break;
 next:
-			bch2_trans_cond_resched(&trans);
 			bch2_btree_iter_next_node(&iter);
 		}
 		if (ret == -EINTR)
@@ -931,6 +932,10 @@ next:
 	if (ret)
 		bch_err(c, "error %i in bch2_move_btree", ret);
 
+	/* flush relevant btree updates */
+	closure_wait_event(&c->btree_interior_update_wait,
+			   !bch2_btree_interior_updates_nr_pending(c));
+
 	progress_list_del(c, stats);
 	return ret;
 }
@@ -1074,10 +1079,6 @@ int bch2_data_job(struct bch_fs *c,
 				      op.start_btree,	op.start_pos,
 				      op.end_btree,	op.end_pos,
 				      rereplicate_btree_pred, c, stats) ?: ret;
-
-		closure_wait_event(&c->btree_interior_update_wait,
-				   !bch2_btree_interior_updates_nr_pending(c));
-
 		ret = bch2_replicas_gc2(c) ?: ret;
 
 		ret = bch2_move_data(c,
diff --git a/libbcachefs/super.c b/libbcachefs/super.c
index bb633e3d..486a0199 100644
--- a/libbcachefs/super.c
+++ b/libbcachefs/super.c
@@ -1585,6 +1585,8 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
 	struct bch_dev *ca = NULL;
 	struct bch_sb_field_members *mi;
 	struct bch_member dev_mi;
+	struct bucket_array *buckets;
+	struct bucket *g;
 	unsigned dev_idx, nr_devices, u64s;
 	int ret;
 
@@ -1688,6 +1690,16 @@ have_slot:
 
 	bch2_dev_usage_journal_reserve(c);
 
+	/*
+	 * Clear marks before marking transactionally in the btree, so that
+	 * per-device accounting gets done correctly:
+	 */
+	down_read(&ca->bucket_lock);
+	buckets = bucket_array(ca);
+	for_each_bucket(g, buckets)
+		atomic64_set(&g->_mark.v, 0);
+	up_read(&ca->bucket_lock);
+
 	err = "error marking superblock";
 	ret = bch2_trans_mark_dev_sb(c, ca);
 	if (ret)