Btrfs: set trans to null in reserve_metadata_bytes if we commit the transaction

btrfs_commit_transaction will free our trans, but because we pass trans to
shrink_delalloc we could possibly have a use after free situation.  So instead
if we commit the transaction, set trans to null and set committed to true so we
don't keep trying to commit a transaction.  This fixes a panic I could reproduce
at will.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
This commit is contained in:
Josef Bacik 2010-10-26 12:52:53 -04:00
parent 0e78340f3c
commit 382279336f

View file

@ -3157,6 +3157,7 @@ static int reserve_metadata_bytes(struct btrfs_trans_handle *trans,
int retries = 0;
int ret = 0;
bool reserved = false;
bool committed = false;
again:
ret = -ENOSPC;
@ -3249,17 +3250,19 @@ static int reserve_metadata_bytes(struct btrfs_trans_handle *trans,
goto out;
ret = -EAGAIN;
if (trans)
if (trans || committed)
goto out;
ret = -ENOSPC;
trans = btrfs_join_transaction(root, 1);
if (IS_ERR(trans))
goto out;
ret = btrfs_commit_transaction(trans, root);
if (!ret)
if (!ret) {
trans = NULL;
committed = true;
goto again;
}
out:
if (reserved) {