[patch v2 2/6] raid5: add a new flag to track if a stripe can be batched
From: shli@kernel.org
Date: 2014-09-10 12:40:11
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 <redacted> --- drivers/md/raid5.c | 12 +++++++++--- drivers/md/raid5.h | 1 + 2 files changed, 10 insertions(+), 3 deletions(-) Index: linux/drivers/md/raid5.c ===================================================================
--- linux.orig/drivers/md/raid5.c 2014-09-10 19:21:08.183378868 +0800
+++ linux/drivers/md/raid5.c 2014-09-10 19:21:08.179378919 +0800@@ -558,6 +558,7 @@ retry: 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,
@@ -2653,7 +2654,8 @@ schedule_reconstruction(struct stripe_he * 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;
@@ -2686,6 +2688,9 @@ static int add_stripe_bio(struct stripe_ 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;
@@ -3754,6 +3759,7 @@ static void handle_stripe(struct stripe_ 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' */
@@ -4739,7 +4745,7 @@ static void make_request(struct mddev *m } 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
@@ -5148,7 +5154,7 @@ static int retry_aligned_read(struct r5 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;
Index: linux/drivers/md/raid5.h ===================================================================
--- linux.orig/drivers/md/raid5.h 2014-09-10 19:21:08.183378868 +0800
+++ linux/drivers/md/raid5.h 2014-09-10 19:21:08.179378919 +0800@@ -327,6 +327,7 @@ enum { STRIPE_ON_UNPLUG_LIST, STRIPE_DISCARD, STRIPE_ON_RELEASE_LIST, + STRIPE_BATCH_READY, }; /*