From 10d82c5f0d167ef75a2d8d7d4eed9ee43d3369c9 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 8 May 2015 18:19:33 +1000 Subject: [PATCH] md/raid5: avoid reading parity blocks for full-stripe write to degraded array When performing a reconstruct write, we need to read all blocks that are not being over-written .. except the parity (P and Q) blocks. The code currently reads these (as they are not being over-written!) unnecessarily. Signed-off-by: NeilBrown Fixes: ea664c8245f3 ("md/raid5: need_this_block: tidy/fix last condition.") --- drivers/md/raid5.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 415cac6d89bd..85dc0e67fb88 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3282,7 +3282,9 @@ static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s, /* reconstruct-write isn't being forced */ return 0; for (i = 0; i < s->failed; i++) { - if (!test_bit(R5_UPTODATE, &fdev[i]->flags) && + if (s->failed_num[i] != sh->pd_idx && + s->failed_num[i] != sh->qd_idx && + !test_bit(R5_UPTODATE, &fdev[i]->flags) && !test_bit(R5_OVERWRITE, &fdev[i]->flags)) return 1; } -- 2.20.1