From da41ba65972532a04f73927c903029a7ec3bc2ed Mon Sep 17 00:00:00 2001 From: "shli@kernel.org" Date: Mon, 15 Dec 2014 12:57:03 +1100 Subject: [PATCH] raid5: add a new flag to track if a stripe can be batched A freshly new stripe with write request can be batched. Any time the stripe is handled or new read is queued, the flag will be cleared. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown --- drivers/md/raid5.c | 12 +++++++++--- drivers/md/raid5.h | 1 + 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 7fb510e54548..49b0f23dbad2 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -555,6 +555,7 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) goto retry; insert_hash(conf, sh); sh->cpu = smp_processor_id(); + set_bit(STRIPE_BATCH_READY, &sh->state); } static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector, @@ -2645,7 +2646,8 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, * toread/towrite point to the first in a chain. * The bi_next chain must be in order. */ -static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) +static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, + int forwrite, int previous) { struct bio **bip; struct r5conf *conf = sh->raid_conf; @@ -2678,6 +2680,9 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi)) goto overlap; + if (!forwrite || previous) + clear_bit(STRIPE_BATCH_READY, &sh->state); + BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next); if (*bip) bi->bi_next = *bip; @@ -3824,6 +3829,7 @@ static void handle_stripe(struct stripe_head *sh) return; } + clear_bit(STRIPE_BATCH_READY, &sh->state); if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { spin_lock(&sh->stripe_lock); /* Cannot process 'sync' concurrently with 'discard' */ @@ -4793,7 +4799,7 @@ static void make_request(struct mddev *mddev, struct bio * bi) } if (test_bit(STRIPE_EXPANDING, &sh->state) || - !add_stripe_bio(sh, bi, dd_idx, rw)) { + !add_stripe_bio(sh, bi, dd_idx, rw, previous)) { /* Stripe is busy expanding or * add failed due to overlap. Flush everything * and wait a while @@ -5206,7 +5212,7 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) return handled; } - if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { + if (!add_stripe_bio(sh, raid_bio, dd_idx, 0, 0)) { release_stripe(sh); raid5_set_bi_processed_stripes(raid_bio, scnt); conf->retry_read_aligned = raid_bio; diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 1d0f241d7d3b..37644e3d5293 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -327,6 +327,7 @@ enum { STRIPE_ON_UNPLUG_LIST, STRIPE_DISCARD, STRIPE_ON_RELEASE_LIST, + STRIPE_BATCH_READY, }; /*