On Mon, May 23, 2016 at 05:25:06PM -0700, Song Liu wrote:
> In current handle_stripe_dirtying, the code prefers rmw with
> PARITY_ENABLE_RMW; while prefers rcw with PARITY_PREFER_RMW.
>
> This patch reverses this behavior.
>
> Signed-off-by: Song Liu <songliubraving@xxxxxx>
> Signed-off-by: Shaohua Li <shli@xxxxxx>
> ---
> drivers/md/raid5.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index 8959e6d..ad9e15a 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -3600,7 +3600,7 @@ static void handle_stripe_dirtying(struct r5conf *conf,
> pr_debug("for sector %llu, rmw=%d rcw=%d\n",
> (unsigned long long)sh->sector, rmw, rcw);
> set_bit(STRIPE_HANDLE, &sh->state);
> - if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_ENABLE_RMW)) && rmw > 0) {
> + if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_PREFER_RMW)) && rmw > 0) {
> /* prefer read-modify-write, but need to get some data */
> if (conf->mddev->queue)
> blk_add_trace_msg(conf->mddev->queue,
> @@ -3627,7 +3627,7 @@ static void handle_stripe_dirtying(struct r5conf *conf,
> }
> }
> }
> - if ((rcw < rmw || (rcw == rmw && conf->rmw_level != PARITY_ENABLE_RMW)) && rcw > 0) {
> + if ((rcw < rmw || (rcw == rmw && conf->rmw_level != PARITY_PREFER_RMW)) && rcw > 0) {
> /* want reconstruct write, but need to get some data */
> int qread =0;
> rcw = 0;
The patch looks correct, I'll apply.
I'm wondering why original code is in current way. It dosn't work like what the
patch log (d06f191f8ecae) describes. Neil/Markus, is any patch missed?
Thanks,
Shaohua
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