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 <shli@xxxxxxxxxxxx>
---
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,
};
/*
--
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