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

Jan Kara
2024-07-24T09:20:07Z

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@linux.dev>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

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@suse.com>
SUSE Labs, CR