Commit 889bfa39 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: drop log root for dropped roots 



If we fsync on a subvolume and create a log root for that volume, and
then later delete that subvolume we'll never clean up its log root.  Fix
this by making switch_commit_roots free the log for any dropped roots we
encounter.  The extra churn is because we need a btrfs_trans_handle, not
the btrfs_transaction.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 668e48af

fs/btrfs/transaction.c

+12 −10
Original line number Diff line number Diff line
@@ -147,13 +147,14 @@ void btrfs_put_transaction(struct btrfs_transaction *transaction) 
	}

}



static noinline void switch_commit_roots(struct btrfs_transaction *trans)

static noinline void switch_commit_roots(struct btrfs_trans_handle *trans)

{

	struct btrfs_transaction *cur_trans = trans->transaction;

	struct btrfs_fs_info *fs_info = trans->fs_info;

	struct btrfs_root *root, *tmp;



	down_write(&fs_info->commit_root_sem);

	list_for_each_entry_safe(root, tmp, &trans->switch_commits,

	list_for_each_entry_safe(root, tmp, &cur_trans->switch_commits,

				 dirty_list) {

		list_del_init(&root->dirty_list);

		free_extent_buffer(root->commit_root);
@@ -165,16 +166,17 @@ static noinline void switch_commit_roots(struct btrfs_transaction *trans) 
	}



	/* We can free old roots now. */

	spin_lock(&trans->dropped_roots_lock);

	while (!list_empty(&trans->dropped_roots)) {

		root = list_first_entry(&trans->dropped_roots,

	spin_lock(&cur_trans->dropped_roots_lock);

	while (!list_empty(&cur_trans->dropped_roots)) {

		root = list_first_entry(&cur_trans->dropped_roots,

					struct btrfs_root, root_list);

		list_del_init(&root->root_list);

		spin_unlock(&trans->dropped_roots_lock);

		spin_unlock(&cur_trans->dropped_roots_lock);

		btrfs_free_log(trans, root);

		btrfs_drop_and_free_fs_root(fs_info, root);

		spin_lock(&trans->dropped_roots_lock);

		spin_lock(&cur_trans->dropped_roots_lock);

	}

	spin_unlock(&trans->dropped_roots_lock);

	spin_unlock(&cur_trans->dropped_roots_lock);

	up_write(&fs_info->commit_root_sem);

}
@@ -1421,7 +1423,7 @@ static int qgroup_account_snapshot(struct btrfs_trans_handle *trans, 
	ret = commit_cowonly_roots(trans);

	if (ret)

		goto out;

	switch_commit_roots(trans->transaction);

	switch_commit_roots(trans);

	ret = btrfs_write_and_wait_transaction(trans);

	if (ret)

		btrfs_handle_fs_error(fs_info, ret,
@@ -2301,7 +2303,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) 
	list_add_tail(&fs_info->chunk_root->dirty_list,

		      &cur_trans->switch_commits);



	switch_commit_roots(cur_trans);

	switch_commit_roots(trans);



	ASSERT(list_empty(&cur_trans->dirty_bgs));

	ASSERT(list_empty(&cur_trans->io_bgs));

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