Commit 4bd06f07 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Fixes for snapshot_tree.master_subvol 



Ensure that snapshot_tree.master_subvol is cleared when we delete the
master subvolume in a tree of snapshots, and allow for snapshot trees
that don't have a master subvolume in fsck.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent b5e4cd08

fs/bcachefs/snapshot.c

+7 −5
Original line number Diff line number Diff line
@@ -495,6 +495,9 @@ static int check_snapshot_tree(struct btree_trans *trans, 
		goto err;

	}



	if (!st.v->master_subvol)

		goto out;



	ret = bch2_subvolume_get(trans, le32_to_cpu(st.v->master_subvol), false, &subvol);

	if (ret && !bch2_err_matches(ret, ENOENT))

		goto err;
@@ -538,6 +541,7 @@ static int check_snapshot_tree(struct btree_trans *trans, 
		u->v.master_subvol = cpu_to_le32(subvol_id);

		st = snapshot_tree_i_to_s_c(u);

	}

out:

err:

fsck_err:

	bch2_trans_iter_exit(trans, &snapshot_iter);
@@ -1037,13 +1041,11 @@ int bch2_check_key_has_snapshot(struct btree_trans *trans, 
int bch2_snapshot_node_set_deleted(struct btree_trans *trans, u32 id)

{

	struct btree_iter iter;

	struct bkey_i_snapshot *s;

	int ret = 0;



	s = bch2_bkey_get_mut_typed(trans, &iter,

	struct bkey_i_snapshot *s =

		bch2_bkey_get_mut_typed(trans, &iter,

				    BTREE_ID_snapshots, POS(0, id),

				    0, snapshot);

	ret = PTR_ERR_OR_ZERO(s);

	int ret = PTR_ERR_OR_ZERO(s);

	if (unlikely(ret)) {

		bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT),

					trans->c, "missing snapshot %u", id);

fs/bcachefs/subvolume.c

+40 −10
Original line number Diff line number Diff line
@@ -409,26 +409,56 @@ static int bch2_subvolumes_reparent(struct btree_trans *trans, u32 subvolid_to_d 
 */

static int __bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)

{

	struct btree_iter iter;

	struct bkey_s_c_subvolume subvol;

	u32 snapid;

	int ret = 0;

	struct btree_iter subvol_iter = {}, snapshot_iter = {}, snapshot_tree_iter = {};



	subvol = bch2_bkey_get_iter_typed(trans, &iter,

	struct bkey_s_c_subvolume subvol =

		bch2_bkey_get_iter_typed(trans, &subvol_iter,

				BTREE_ID_subvolumes, POS(0, subvolid),

				BTREE_ITER_cached|BTREE_ITER_intent,

				subvolume);

	ret = bkey_err(subvol);

	int ret = bkey_err(subvol);

	bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,

				"missing subvolume %u", subvolid);

	if (ret)

		return ret;

		goto err;



	snapid = le32_to_cpu(subvol.v->snapshot);

	u32 snapid = le32_to_cpu(subvol.v->snapshot);



	struct bkey_s_c_snapshot snapshot =

		bch2_bkey_get_iter_typed(trans, &snapshot_iter,

				BTREE_ID_snapshots, POS(0, snapid),

				0, snapshot);

	ret = bkey_err(subvol);

	bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,

				"missing snapshot %u", snapid);

	if (ret)

		goto err;



	u32 treeid = le32_to_cpu(snapshot.v->tree);



	ret =   bch2_btree_delete_at(trans, &iter, 0) ?:

	struct bkey_s_c_snapshot_tree snapshot_tree =

		bch2_bkey_get_iter_typed(trans, &snapshot_tree_iter,

				BTREE_ID_snapshot_trees, POS(0, treeid),

				0, snapshot_tree);



	if (le32_to_cpu(snapshot_tree.v->master_subvol) == subvolid) {

		struct bkey_i_snapshot_tree *snapshot_tree_mut =

			bch2_bkey_make_mut_typed(trans, &snapshot_tree_iter,

						 &snapshot_tree.s_c,

						 0, snapshot_tree);

		ret = PTR_ERR_OR_ZERO(snapshot_tree_mut);

		if (ret)

			goto err;



		snapshot_tree_mut->v.master_subvol = 0;

	}



	ret =   bch2_btree_delete_at(trans, &subvol_iter, 0) ?:

		bch2_snapshot_node_set_deleted(trans, snapid);

	bch2_trans_iter_exit(trans, &iter);

err:

	bch2_trans_iter_exit(trans, &snapshot_tree_iter);

	bch2_trans_iter_exit(trans, &snapshot_iter);

	bch2_trans_iter_exit(trans, &subvol_iter);

	return ret;

}