From c0b32972fb1e1110101702f096c0877afcab9f1d Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 24 Apr 2013 11:42:42 +1000 Subject: [PATCH] md/raid5: avoid an extra write when writing to a known-bad-block. If we write to a known-bad-block it will be flags as having a ReadError by analyse_stripe, but the write will proceed anyway (as it should). Then the read-error handling will kick in an write again, then re-read. We don't need that 'write-again', so set R5_ReWrite so it looks like it has already been done. Then we will just get the re-read, which we want. Reported-by: majianpeng Signed-off-by: NeilBrown --- drivers/md/raid5.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index f31882c..4a7be45 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1887,8 +1887,15 @@ static void raid5_end_write_request(struct bio *bi, int error) &rdev->mddev->recovery); } else if (is_badblock(rdev, sh->sector, STRIPE_SECTORS, - &first_bad, &bad_sectors)) + &first_bad, &bad_sectors)) { set_bit(R5_MadeGood, &sh->dev[i].flags); + if (test_bit(R5_ReadError, &sh->dev[i].flags)) + /* That was a successful write so make + * sure it looks like we already did + * a re-write. + */ + set_bit(R5_ReWrite, &sh->dev[i].flags); + } } rdev_dec_pending(rdev, conf->mddev); -- 2.7.4