[md PATCH 08/14] md/raid1, raid10: move rXbio accounting closer to allocation.
From: NeilBrown <hidden>
Date: 2017-02-16 04:39:02
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
When raid1 or raid10 need find they will need to allocate a new r1bio/r10bio, in order to work around a known bad block, the 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 <redacted> --- drivers/md/raid1.c | 23 ++++++++++------------- drivers/md/raid10.c | 22 +++++++++------------- 2 files changed, 19 insertions(+), 26 deletions(-)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 7b0f647bcccb..c1d0675880fb 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c@@ -1326,18 +1326,9 @@ 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);
@@ -1426,10 +1417,16 @@ 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 = mempool_alloc(conf->r1bio_pool, GFP_NOIO); r1_bio->master_bio = bio; r1_bio->sectors = bio_sectors(bio) - sectors_handled;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 1920756828df..9258cbe233bb 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;
@@ -1491,10 +1481,16 @@ 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;