Re: [PATCH 2/4] ext4: fix incorrect tid assumption in __jbd2_log_wait_for_space()

[Jan Kara]

On Tue 23-07-24 16:44:00, Luis Henriques (SUSE) wrote:
> Function __jbd2_log_wait_for_space() assumes that '0' is not a valid value
> for transaction IDs, which is incorrect.  Don't assume that and invoke
> jbd2_log_wait_commit() if the journal had a committing transaction instead.
> 
> Signed-off-by: Luis Henriques (SUSE) <luis.henriques@xxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  fs/jbd2/checkpoint.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
> index 951f78634adf..77bc522e6821 100644
> --- a/fs/jbd2/checkpoint.c
> +++ b/fs/jbd2/checkpoint.c
> @@ -79,9 +79,12 @@ __releases(&journal->j_state_lock)
>  		if (space_left < nblocks) {
>  			int chkpt = journal->j_checkpoint_transactions != NULL;
>  			tid_t tid = 0;
> +			bool has_transaction = false;
>  
> -			if (journal->j_committing_transaction)
> +			if (journal->j_committing_transaction) {
>  				tid = journal->j_committing_transaction->t_tid;
> +				has_transaction = true;
> +			}
>  			spin_unlock(&journal->j_list_lock);
>  			write_unlock(&journal->j_state_lock);
>  			if (chkpt) {
> @@ -89,7 +92,7 @@ __releases(&journal->j_state_lock)
>  			} else if (jbd2_cleanup_journal_tail(journal) == 0) {
>  				/* We were able to recover space; yay! */
>  				;
> -			} else if (tid) {
> +			} else if (has_transaction) {
>  				/*
>  				 * jbd2_journal_commit_transaction() may want
>  				 * to take the checkpoint_mutex if JBD2_FLUSHED
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR