On Tue, Mar 24, 2020 at 06:44:53PM +0100, Christoph Hellwig wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> Commit and unmount records records do not need start records to be
> written, so rearrange the logic in xlog_write() to remove the need
> to check for XLOG_TIC_INITED to determine if we should account for
> the space used by a start record.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Looks pretty straightforward,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/xfs/xfs_log.c | 38 ++++++++++++--------------------------
> 1 file changed, 12 insertions(+), 26 deletions(-)
>
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index bf071552094a..116f59b16b04 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -2349,39 +2349,27 @@ xlog_write(
> uint flags)
> {
> struct xlog_in_core *iclog = NULL;
> - struct xfs_log_iovec *vecp;
> - struct xfs_log_vec *lv;
> + struct xfs_log_vec *lv = log_vector;
> + struct xfs_log_iovec *vecp = lv->lv_iovecp;
> + int index = 0;
> int len;
> - int index;
> int partial_copy = 0;
> int partial_copy_len = 0;
> int contwr = 0;
> int record_cnt = 0;
> int data_cnt = 0;
> int error = 0;
> - bool need_start_rec = true;
> -
> - *start_lsn = 0;
> -
> + bool need_start_rec;
>
> /*
> - * Region headers and bytes are already accounted for.
> - * We only need to take into account start records and
> - * split regions in this function.
> + * If this is a commit or unmount transaction, we don't need a start
> + * record to be written. We do, however, have to account for the
> + * commit or unmount header that gets written. Hence we always have
> + * to account for an extra xlog_op_header here.
> */
> - if (ticket->t_flags & XLOG_TIC_INITED) {
> - ticket->t_curr_res -= sizeof(struct xlog_op_header);
> + ticket->t_curr_res -= sizeof(struct xlog_op_header);
> + if (ticket->t_flags & XLOG_TIC_INITED)
> ticket->t_flags &= ~XLOG_TIC_INITED;
> - }
> -
> - /*
> - * Commit record headers need to be accounted for. These
> - * come in as separate writes so are easy to detect.
> - */
> - if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS)) {
> - ticket->t_curr_res -= sizeof(struct xlog_op_header);
> - need_start_rec = false;
> - }
>
> if (ticket->t_curr_res < 0) {
> xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
> @@ -2390,11 +2378,9 @@ xlog_write(
> xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
> }
>
> + need_start_rec = !(flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS));
> len = xlog_write_calc_vec_length(ticket, log_vector, need_start_rec);
> -
> - index = 0;
> - lv = log_vector;
> - vecp = lv->lv_iovecp;
> + *start_lsn = 0;
> while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
> void *ptr;
> int log_offset;
> --
> 2.25.1
>
