Re: [PATCH v3] jbd2: preserve original nofs flag during journal restart

From: Theodore Ts'o
Date: Sat May 20 2017 - 00:09:57 EST


On Thu, May 18, 2017 at 09:28:50AM -0700, Tahsin Erdogan wrote:
> When a transaction starts, start_this_handle() saves current
> PF_MEMALLOC_NOFS value so that it can be restored at journal stop time.
> Journal restart is a special case that calls start_this_handle() without
> stopping the transaction. start_this_handle() isn't aware that the
> original value is already stored so it overwrites it with current value.
>
> For instance, a call sequence like below leaves PF_MEMALLOC_NOFS flag set
> at the end:
>
> jbd2_journal_start()
> jbd2__journal_restart()
> jbd2_journal_stop()
>
> Make jbd2__journal_restart() restore the original value before calling
> start_this_handle().
>
> Fixes: 81378da64de6 ("jbd2: mark the transaction context with the scope GFP_NOFS context")
> Signed-off-by: Tahsin Erdogan <tahsin@xxxxxxxxxx>
> Reviewed-by: Jan Kara <jack@xxxxxxx>

Thanks, applied.

- Ted