Commit 41257580 authored by Song Liu's avatar Song Liu Committed by Shaohua Li
Browse files

right meaning of PARITY_ENABLE_RMW and PARITY_PREFER_RMW 



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: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 2f7c3a18

drivers/md/raid5.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

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