Btrfs: protect the pending_snapshots list with trans_lock

Currently there is nothing protecting the pending_snapshots list on the
transaction.  We only hold the directory mutex that we are snapshotting and a
read lock on the subvol_sem, so we could race with somebody else creating a
snapshot in a different directory and end up with list corruption.  So protect
this list with the trans_lock.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
This commit is contained in:
Josef Bacik 2011-06-14 15:16:14 -04:00
parent 71d7aed014
commit 8351583e3f

View File

@ -482,8 +482,10 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
BUG_ON(ret);
spin_lock(&root->fs_info->trans_lock);
list_add(&pending_snapshot->list,
&trans->transaction->pending_snapshots);
spin_unlock(&root->fs_info->trans_lock);
if (async_transid) {
*async_transid = trans->transid;
ret = btrfs_commit_transaction_async(trans,