From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: [md PATCH 08/15] md/raid1, raid10: move rXbio accounting closer to allocation. Date: Wed, 15 Mar 2017 14:05:13 +1100 Message-ID: <148954711347.18641.13034185168501168622.stgit@noble> References: <148954692173.18641.1294690639716682540.stgit@noble> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <148954692173.18641.1294690639716682540.stgit@noble> Sender: linux-raid-owner@vger.kernel.org To: Shaohua Li Cc: linux-raid@vger.kernel.org, hch@lst.de List-Id: linux-raid.ids When raid1 or raid10 find they will need to allocate a new r1bio/r10bio, in order to work around a known bad block, they account for the allocation well before the allocation is made. This separation makes the correctness less obvious and requires comments. The accounting needs to be a little before: before the first rXbio is submitted, but that is all. So move the accounting down to where it makes more sense. Signed-off-by: NeilBrown --- drivers/md/raid1.c | 24 +++++++++++------------- drivers/md/raid10.c | 22 +++++++++------------- 2 files changed, 20 insertions(+), 26 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index d3da6b36e670..7e509a894f15 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1436,18 +1436,9 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio) goto retry_write; } - if (max_sectors < r1_bio->sectors) { - /* We are splitting this write into multiple parts, so - * we need to prepare for allocating another r1_bio. - */ + if (max_sectors < r1_bio->sectors) r1_bio->sectors = max_sectors; - spin_lock_irq(&conf->device_lock); - if (bio->bi_phys_segments == 0) - bio->bi_phys_segments = 2; - else - bio->bi_phys_segments++; - spin_unlock_irq(&conf->device_lock); - } + sectors_handled = r1_bio->sector + max_sectors - bio->bi_iter.bi_sector; atomic_set(&r1_bio->remaining, 1); @@ -1553,10 +1544,17 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio) * as it could result in the bio being freed. */ if (sectors_handled < bio_sectors(bio)) { - r1_bio_write_done(r1_bio); - /* We need another r1_bio. It has already been counted + /* We need another r1_bio, which must be accounted * in bio->bi_phys_segments */ + spin_lock_irq(&conf->device_lock); + if (bio->bi_phys_segments == 0) + bio->bi_phys_segments = 2; + else + bio->bi_phys_segments++; + spin_unlock_irq(&conf->device_lock); + + r1_bio_write_done(r1_bio); r1_bio = alloc_r1bio(mddev, bio, sectors_handled); goto retry_write; } diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index b1b1f982a722..20029345f8b6 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1383,18 +1383,8 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, goto retry_write; } - if (max_sectors < r10_bio->sectors) { - /* We are splitting this into multiple parts, so - * we need to prepare for allocating another r10_bio. - */ + if (max_sectors < r10_bio->sectors) r10_bio->sectors = max_sectors; - spin_lock_irq(&conf->device_lock); - if (bio->bi_phys_segments == 0) - bio->bi_phys_segments = 2; - else - bio->bi_phys_segments++; - spin_unlock_irq(&conf->device_lock); - } sectors_handled = r10_bio->sector + max_sectors - bio->bi_iter.bi_sector; @@ -1504,10 +1494,16 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, */ if (sectors_handled < bio_sectors(bio)) { - one_write_done(r10_bio); - /* We need another r10_bio. It has already been counted + /* We need another r10_bio and it needs to be counted * in bio->bi_phys_segments. */ + spin_lock_irq(&conf->device_lock); + if (bio->bi_phys_segments == 0) + bio->bi_phys_segments = 2; + else + bio->bi_phys_segments++; + spin_unlock_irq(&conf->device_lock); + one_write_done(r10_bio); r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO); r10_bio->master_bio = bio;