bcachefs: Make sure we're releasing btree iterators

This wasn't originally required, but this is the model we're moving
towards.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_iter.c

@@ -1729,7 +1729,12 @@ static inline void __bch2_trans_iter_free(struct btree_trans *trans,
 int bch2_trans_iter_put(struct btree_trans *trans,
 			struct btree_iter *iter)
 {
-	int ret = btree_iter_err(iter);
+	int ret;
+
+	if (IS_ERR_OR_NULL(iter))
+		return 0;
+
+	ret = btree_iter_err(iter);
 
 	if (!(trans->iters_touched & (1ULL << iter->idx)) &&
 	    !(iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT))
@@ -1742,6 +1747,9 @@ int bch2_trans_iter_put(struct btree_trans *trans,
 int bch2_trans_iter_free(struct btree_trans *trans,
 			 struct btree_iter *iter)
 {
+	if (IS_ERR_OR_NULL(iter))
+		return 0;
+
 	trans->iters_touched &= ~(1ULL << iter->idx);
 
 	return bch2_trans_iter_put(trans, iter);
@@ -1981,8 +1989,8 @@ struct btree_iter *bch2_trans_copy_iter(struct btree_trans *trans,
 
 	trans->iters_live |= 1ULL << iter->idx;
 	/*
-	 * Don't mark it as touched, we don't need to preserve this iter since
-	 * it's cheap to copy it again:
+	 * We don't need to preserve this iter since it's cheap to copy it
+	 * again - this will cause trans_iter_put() to free it right away:
 	 */
 	trans->iters_touched &= ~(1ULL << iter->idx);
 

fs/bcachefs/fs-common.c

@@ -19,14 +19,15 @@ int bch2_create_trans(struct btree_trans *trans, u64 dir_inum,
 		      struct posix_acl *acl)
 {
 	struct bch_fs *c = trans->c;
-	struct btree_iter *dir_iter;
+	struct btree_iter *dir_iter = NULL;
 	struct bch_hash_info hash = bch2_hash_info_init(c, new_inode);
 	u64 now = bch2_current_time(trans->c);
 	int ret;
 
 	dir_iter = bch2_inode_peek(trans, dir_u, dir_inum, BTREE_ITER_INTENT);
-	if (IS_ERR(dir_iter))
-		return PTR_ERR(dir_iter);
+	ret = PTR_ERR_OR_ZERO(dir_iter);
+	if (ret)
+		goto err;
 
 	bch2_inode_init_late(new_inode, now, uid, gid, mode, rdev, dir_u);
 
@@ -37,20 +38,20 @@ int bch2_create_trans(struct btree_trans *trans, u64 dir_inum,
 				BLOCKDEV_INODE_MAX, 0,
 				&c->unused_inode_hint);
 	if (ret)
-		return ret;
+		goto err;
 
 	if (default_acl) {
 		ret = bch2_set_acl_trans(trans, new_inode, &hash,
 					 default_acl, ACL_TYPE_DEFAULT);
 		if (ret)
-			return ret;
+			goto err;
 	}
 
 	if (acl) {
 		ret = bch2_set_acl_trans(trans, new_inode, &hash,
 					 acl, ACL_TYPE_ACCESS);
 		if (ret)
-			return ret;
+			goto err;
 	}
 
 	if (name) {
@@ -62,48 +63,55 @@ int bch2_create_trans(struct btree_trans *trans, u64 dir_inum,
 
 		ret = bch2_inode_write(trans, dir_iter, dir_u);
 		if (ret)
-			return ret;
+			goto err;
 
 		ret = bch2_dirent_create(trans, dir_inum, &dir_hash,
 					 mode_to_type(new_inode->bi_mode),
 					 name, new_inode->bi_inum,
 					 BCH_HASH_SET_MUST_CREATE);
 		if (ret)
-			return ret;
+			goto err;
 	}
-
-	return 0;
+err:
+	bch2_trans_iter_put(trans, dir_iter);
+	return ret;
 }
 
 int bch2_link_trans(struct btree_trans *trans, u64 dir_inum,
 		    u64 inum, struct bch_inode_unpacked *dir_u,
 		    struct bch_inode_unpacked *inode_u, const struct qstr *name)
 {
-	struct btree_iter *dir_iter, *inode_iter;
+	struct btree_iter *dir_iter = NULL, *inode_iter = NULL;
 	struct bch_hash_info dir_hash;
 	u64 now = bch2_current_time(trans->c);
+	int ret;
 
 	inode_iter = bch2_inode_peek(trans, inode_u, inum, BTREE_ITER_INTENT);
-	if (IS_ERR(inode_iter))
-		return PTR_ERR(inode_iter);
+	ret = PTR_ERR_OR_ZERO(inode_iter);
+	if (ret)
+		goto err;
 
 	inode_u->bi_ctime = now;
 	bch2_inode_nlink_inc(inode_u);
 
 	dir_iter = bch2_inode_peek(trans, dir_u, dir_inum, 0);
-	if (IS_ERR(dir_iter))
-		return PTR_ERR(dir_iter);
+	ret = PTR_ERR_OR_ZERO(dir_iter);
+	if (ret)
+		goto err;
 
 	dir_u->bi_mtime = dir_u->bi_ctime = now;
 
 	dir_hash = bch2_hash_info_init(trans->c, dir_u);
-	bch2_trans_iter_put(trans, dir_iter);
 
-	return bch2_dirent_create(trans, dir_inum, &dir_hash,
+	ret =   bch2_dirent_create(trans, dir_inum, &dir_hash,
 				  mode_to_type(inode_u->bi_mode),
 				  name, inum, BCH_HASH_SET_MUST_CREATE) ?:
 		bch2_inode_write(trans, dir_iter, dir_u) ?:
 		bch2_inode_write(trans, inode_iter, inode_u);
+err:
+	bch2_trans_iter_put(trans, dir_iter);
+	bch2_trans_iter_put(trans, inode_iter);
+	return ret;
 }
 
 int bch2_unlink_trans(struct btree_trans *trans,
@@ -111,39 +119,49 @@ int bch2_unlink_trans(struct btree_trans *trans,
 		      struct bch_inode_unpacked *inode_u,
 		      const struct qstr *name)
 {
-	struct btree_iter *dir_iter, *dirent_iter, *inode_iter;
+	struct btree_iter *dir_iter = NULL, *dirent_iter = NULL,
+			  *inode_iter = NULL;
 	struct bch_hash_info dir_hash;
 	u64 inum, now = bch2_current_time(trans->c);
 	struct bkey_s_c k;
+	int ret;
 
 	dir_iter = bch2_inode_peek(trans, dir_u, dir_inum, BTREE_ITER_INTENT);
-	if (IS_ERR(dir_iter))
-		return PTR_ERR(dir_iter);
+	ret = PTR_ERR_OR_ZERO(dir_iter);
+	if (ret)
+		goto err;
 
 	dir_hash = bch2_hash_info_init(trans->c, dir_u);
 
 	dirent_iter = __bch2_dirent_lookup_trans(trans, dir_inum, &dir_hash,
 						 name, BTREE_ITER_INTENT);
-	if (IS_ERR(dirent_iter))
-		return PTR_ERR(dirent_iter);
+	ret = PTR_ERR_OR_ZERO(dirent_iter);
+	if (ret)
+		goto err;
 
 	k = bch2_btree_iter_peek_slot(dirent_iter);
 	inum = le64_to_cpu(bkey_s_c_to_dirent(k).v->d_inum);
 
 	inode_iter = bch2_inode_peek(trans, inode_u, inum, BTREE_ITER_INTENT);
-	if (IS_ERR(inode_iter))
-		return PTR_ERR(inode_iter);
+	ret = PTR_ERR_OR_ZERO(inode_iter);
+	if (ret)
+		goto err;
 
 	dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
 	dir_u->bi_nlink -= S_ISDIR(inode_u->bi_mode);
 	bch2_inode_nlink_dec(inode_u);
 
-	return  (S_ISDIR(inode_u->bi_mode)
+	ret =   (S_ISDIR(inode_u->bi_mode)
 		 ? bch2_empty_dir_trans(trans, inum)
 		 : 0) ?:
 		bch2_dirent_delete_at(trans, &dir_hash, dirent_iter) ?:
 		bch2_inode_write(trans, dir_iter, dir_u) ?:
 		bch2_inode_write(trans, inode_iter, inode_u);
+err:
+	bch2_trans_iter_put(trans, inode_iter);
+	bch2_trans_iter_put(trans, dirent_iter);
+	bch2_trans_iter_put(trans, dir_iter);
+	return ret;
 }
 
 bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
@@ -179,24 +197,26 @@ int bch2_rename_trans(struct btree_trans *trans,
 		      const struct qstr *dst_name,
 		      enum bch_rename_mode mode)
 {
-	struct btree_iter *src_dir_iter, *dst_dir_iter = NULL;
-	struct btree_iter *src_inode_iter, *dst_inode_iter = NULL;
+	struct btree_iter *src_dir_iter = NULL, *dst_dir_iter = NULL;
+	struct btree_iter *src_inode_iter = NULL, *dst_inode_iter = NULL;
 	struct bch_hash_info src_hash, dst_hash;
 	u64 src_inode, dst_inode, now = bch2_current_time(trans->c);
 	int ret;
 
 	src_dir_iter = bch2_inode_peek(trans, src_dir_u, src_dir,
 				       BTREE_ITER_INTENT);
-	if (IS_ERR(src_dir_iter))
-		return PTR_ERR(src_dir_iter);
+	ret = PTR_ERR_OR_ZERO(src_dir_iter);
+	if (ret)
+		goto err;
 
 	src_hash = bch2_hash_info_init(trans->c, src_dir_u);
 
 	if (dst_dir != src_dir) {
 		dst_dir_iter = bch2_inode_peek(trans, dst_dir_u, dst_dir,
 					       BTREE_ITER_INTENT);
-		if (IS_ERR(dst_dir_iter))
-			return PTR_ERR(dst_dir_iter);
+		ret = PTR_ERR_OR_ZERO(dst_dir_iter);
+		if (ret)
+			goto err;
 
 		dst_hash = bch2_hash_info_init(trans->c, dst_dir_u);
 	} else {
@@ -211,38 +231,48 @@ int bch2_rename_trans(struct btree_trans *trans,
 				 dst_name, &dst_inode,
 				 mode);
 	if (ret)
-		return ret;
+		goto err;
 
 	src_inode_iter = bch2_inode_peek(trans, src_inode_u, src_inode,
 					 BTREE_ITER_INTENT);
-	if (IS_ERR(src_inode_iter))
-		return PTR_ERR(src_inode_iter);
+	ret = PTR_ERR_OR_ZERO(src_inode_iter);
+	if (ret)
+		goto err;
 
 	if (dst_inode) {
 		dst_inode_iter = bch2_inode_peek(trans, dst_inode_u, dst_inode,
 						 BTREE_ITER_INTENT);
-		if (IS_ERR(dst_inode_iter))
-			return PTR_ERR(dst_inode_iter);
+		ret = PTR_ERR_OR_ZERO(dst_inode_iter);
+		if (ret)
+			goto err;
 	}
 
 	if (mode == BCH_RENAME_OVERWRITE) {
 		if (S_ISDIR(src_inode_u->bi_mode) !=
-		    S_ISDIR(dst_inode_u->bi_mode))
-			return -ENOTDIR;
+		    S_ISDIR(dst_inode_u->bi_mode)) {
+			ret = -ENOTDIR;
+			goto err;
+		}
 
 		if (S_ISDIR(dst_inode_u->bi_mode) &&
-		    bch2_empty_dir_trans(trans, dst_inode))
-			return -ENOTEMPTY;
+		    bch2_empty_dir_trans(trans, dst_inode)) {
+			ret = -ENOTEMPTY;
+			goto err;
+		}
 	}
 
 	if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) &&
-	    S_ISDIR(src_inode_u->bi_mode))
-		return -EXDEV;
+	    S_ISDIR(src_inode_u->bi_mode)) {
+		ret = -EXDEV;
+		goto err;
+	}
 
 	if (mode == BCH_RENAME_EXCHANGE &&
 	    bch2_reinherit_attrs(dst_inode_u, src_dir_u) &&
-	    S_ISDIR(dst_inode_u->bi_mode))
-		return -EXDEV;
+	    S_ISDIR(dst_inode_u->bi_mode)) {
+		ret = -EXDEV;
+		goto err;
+	}
 
 	if (S_ISDIR(src_inode_u->bi_mode)) {
 		src_dir_u->bi_nlink--;
@@ -270,7 +300,7 @@ int bch2_rename_trans(struct btree_trans *trans,
 	if (dst_inode)
 		dst_inode_u->bi_ctime	= now;
 
-	return  bch2_inode_write(trans, src_dir_iter, src_dir_u) ?:
+	ret =   bch2_inode_write(trans, src_dir_iter, src_dir_u) ?:
 		(src_dir != dst_dir
 		 ? bch2_inode_write(trans, dst_dir_iter, dst_dir_u)
 		 : 0 ) ?:
@@ -278,4 +308,10 @@ int bch2_rename_trans(struct btree_trans *trans,
 		(dst_inode
 		 ? bch2_inode_write(trans, dst_inode_iter, dst_inode_u)
 		 : 0 );
+err:
+	bch2_trans_iter_put(trans, dst_inode_iter);
+	bch2_trans_iter_put(trans, src_inode_iter);
+	bch2_trans_iter_put(trans, dst_dir_iter);
+	bch2_trans_iter_put(trans, src_dir_iter);
+	return ret;
 }

fs/bcachefs/inode.c

@@ -362,16 +362,16 @@ int bch2_inode_create(struct btree_trans *trans,
 		      struct bch_inode_unpacked *inode_u,
 		      u64 min, u64 max, u64 *hint)
 {
-	struct bch_fs *c = trans->c;
 	struct bkey_inode_buf *inode_p;
-	struct btree_iter *iter;
+	struct btree_iter *iter = NULL;
+	struct bkey_s_c k;
 	u64 start;
 	int ret;
 
 	if (!max)
 		max = ULLONG_MAX;
 
-	if (c->opts.inodes_32bit)
+	if (trans->c->opts.inodes_32bit)
 		max = min_t(u64, max, U32_MAX);
 
 	start = READ_ONCE(*hint);
@@ -382,48 +382,37 @@ int bch2_inode_create(struct btree_trans *trans,
 	inode_p = bch2_trans_kmalloc(trans, sizeof(*inode_p));
 	if (IS_ERR(inode_p))
 		return PTR_ERR(inode_p);
-
-	iter = bch2_trans_get_iter(trans,
-			BTREE_ID_INODES, POS(start, 0),
-			BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
-	if (IS_ERR(iter))
-		return PTR_ERR(iter);
 again:
-	while (1) {
-		struct bkey_s_c k = bch2_btree_iter_peek_slot(iter);
-
-		ret = bkey_err(k);
-		if (ret)
-			return ret;
+	for_each_btree_key(trans, iter, BTREE_ID_INODES, POS(start, 0),
+			   BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
+		if (iter->pos.inode > max)
+			break;
 
-		switch (k.k->type) {
-		case KEY_TYPE_inode:
-			/* slot used */
-			if (iter->pos.inode >= max)
-				goto out;
+		if (k.k->type != KEY_TYPE_inode)
+			goto found_slot;
+	}
 
-			bch2_btree_iter_next_slot(iter);
-			break;
+	bch2_trans_iter_put(trans, iter);
 
-		default:
-			*hint			= k.k->p.inode;
-			inode_u->bi_inum	= k.k->p.inode;
-			inode_u->bi_generation	= bkey_generation(k);
+	if (ret)
+		return ret;
 
-			bch2_inode_pack(inode_p, inode_u);
-			bch2_trans_update(trans, iter, &inode_p->inode.k_i, 0);
-			return 0;
-		}
-	}
-out:
 	if (start != min) {
 		/* Retry from start */
 		start = min;
-		bch2_btree_iter_set_pos(iter, POS(start, 0));
 		goto again;
 	}
 
 	return -ENOSPC;
+found_slot:
+	*hint			= k.k->p.inode;
+	inode_u->bi_inum	= k.k->p.inode;
+	inode_u->bi_generation	= bkey_generation(k);
+
+	bch2_inode_pack(inode_p, inode_u);
+	bch2_trans_update(trans, iter, &inode_p->inode.k_i, 0);
+	bch2_trans_iter_put(trans, iter);
+	return 0;
 }
 
 int bch2_inode_rm(struct bch_fs *c, u64 inode_nr)
@@ -518,14 +507,13 @@ int bch2_inode_find_by_inum_trans(struct btree_trans *trans, u64 inode_nr,
 	k = bch2_btree_iter_peek_slot(iter);
 	ret = bkey_err(k);
 	if (ret)
-		return ret;
+		goto err;
 
 	ret = k.k->type == KEY_TYPE_inode
 		? bch2_inode_unpack(bkey_s_c_to_inode(k), inode)
 		: -ENOENT;
-
+err:
 	bch2_trans_iter_put(trans, iter);
-
 	return ret;
 }
 

fs/bcachefs/reflink.c

@@ -128,10 +128,9 @@ static int bch2_make_extent_indirect(struct btree_trans *trans,
 
 	bch2_trans_update(trans, extent_iter, &r_p->k_i, 0);
 err:
-	if (!IS_ERR(reflink_iter)) {
+	if (!IS_ERR(reflink_iter))
 		c->reflink_hint = reflink_iter->pos.offset;
-		bch2_trans_iter_put(trans, reflink_iter);
-	}
+	bch2_trans_iter_put(trans, reflink_iter);
 
 	return ret;
 }

fs/bcachefs/str_hash.h

@@ -262,10 +262,8 @@ int bch2_hash_set(struct btree_trans *trans,
 	if (!ret)
 		ret = -ENOSPC;
 out:
-	if (!IS_ERR_OR_NULL(slot))
-		bch2_trans_iter_put(trans, slot);
-	if (!IS_ERR_OR_NULL(iter))
-		bch2_trans_iter_put(trans, iter);
+	bch2_trans_iter_put(trans, slot);
+	bch2_trans_iter_put(trans, iter);
 
 	return ret;
 found: