Re: [PATCH] Btrfs: assert send doesn't attempt to start transactions

[Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>]

(2014/06/25 1:48), Filipe David Borba Manana wrote:
> When starting a transaction just assert that current->journal_info
> doesn't contain a send transaction stub, since send isn't supposed
> to start transactions and when it finishes (either successfully or
> not) it's supposed to set current->journal_info to NULL.
> 
> This is motivated by the change titled:
> 
>      Btrfs: fix crash when starting transaction
> 
> Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>

Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>

Thanks,
Satoru

> ---
>   fs/btrfs/transaction.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
> index 614eac3..47870ca 100644
> --- a/fs/btrfs/transaction.c
> +++ b/fs/btrfs/transaction.c
> @@ -386,11 +386,13 @@ start_transaction(struct btrfs_root *root, u64 num_items, unsigned int type,
>   	bool reloc_reserved = false;
>   	int ret;
>   
> +	/* Send isn't supposed to start transactions. */
> +	ASSERT(current->journal_info != (void *)BTRFS_SEND_TRANS_STUB);
> +
>   	if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
>   		return ERR_PTR(-EROFS);
>   
> -	if (current->journal_info &&
> -	    current->journal_info != (void *)BTRFS_SEND_TRANS_STUB) {
> +	if (current->journal_info) {
>   		WARN_ON(type & TRANS_EXTWRITERS);
>   		h = current->journal_info;
>   		h->use_count++;
>