From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: linux-block@vger.kernel.org
Cc: axboe@kernel.dk, shli@kernel.org, Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: [PATCH 4/9] md: raid10 nowait support
Date: Wed, 4 Oct 2017 08:55:06 -0500 [thread overview]
Message-ID: <20171004135511.26110-5-rgoldwyn@suse.de> (raw)
In-Reply-To: <20171004135511.26110-1-rgoldwyn@suse.de>
From: Goldwyn Rodrigues <rgoldwyn@suse.com>
Bail and status to EAGAIN if raid10 is going to wait for:
+ barriers
+ reshape operation
+ Too many queued requests
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
drivers/md/raid10.c | 67 ++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 51 insertions(+), 16 deletions(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 374df5796649..b0701f5751fe 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -969,8 +969,9 @@ static void lower_barrier(struct r10conf *conf)
wake_up(&conf->wait_barrier);
}
-static void wait_barrier(struct r10conf *conf)
+static bool wait_barrier(struct r10conf *conf, bool nowait)
{
+ bool ret = true;
spin_lock_irq(&conf->resync_lock);
if (conf->barrier) {
conf->nr_waiting++;
@@ -984,19 +985,25 @@ static void wait_barrier(struct r10conf *conf)
* count down.
*/
raid10_log(conf->mddev, "wait barrier");
- wait_event_lock_irq(conf->wait_barrier,
- !conf->barrier ||
- (atomic_read(&conf->nr_pending) &&
- current->bio_list &&
- (!bio_list_empty(¤t->bio_list[0]) ||
- !bio_list_empty(¤t->bio_list[1]))),
- conf->resync_lock);
+ if (!nowait)
+ wait_event_lock_irq(conf->wait_barrier,
+ !conf->barrier ||
+ (atomic_read(&conf->nr_pending) &&
+ current->bio_list &&
+ (!bio_list_empty(¤t->bio_list[0]) ||
+ !bio_list_empty(¤t->bio_list[1]))),
+ conf->resync_lock);
+ else
+ ret = false;
conf->nr_waiting--;
if (!conf->nr_waiting)
wake_up(&conf->wait_barrier);
}
- atomic_inc(&conf->nr_pending);
+ /* Do not increment nr_pending if we din't wait */
+ if (ret)
+ atomic_inc(&conf->nr_pending);
spin_unlock_irq(&conf->resync_lock);
+ return ret;
}
static void allow_barrier(struct r10conf *conf)
@@ -1148,7 +1155,10 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
* thread has put up a bar for new requests.
* Continue immediately if no resync is active currently.
*/
- wait_barrier(conf);
+ if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) {
+ bio_wouldblock_error(bio);
+ return;
+ }
sectors = r10_bio->sectors;
while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
@@ -1159,12 +1169,16 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
* pass
*/
raid10_log(conf->mddev, "wait reshape");
+ if (bio->bi_opf & REQ_NOWAIT) {
+ bio_wouldblock_error(bio);
+ return;
+ }
allow_barrier(conf);
wait_event(conf->wait_barrier,
conf->reshape_progress <= bio->bi_iter.bi_sector ||
conf->reshape_progress >= bio->bi_iter.bi_sector +
sectors);
- wait_barrier(conf);
+ wait_barrier(conf, false);
}
rdev = read_balance(conf, r10_bio, &max_sectors);
@@ -1298,12 +1312,19 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
* thread has put up a bar for new requests.
* Continue immediately if no resync is active currently.
*/
- wait_barrier(conf);
+ if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) {
+ bio_wouldblock_error(bio);
+ return;
+ }
sectors = r10_bio->sectors;
while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
bio->bi_iter.bi_sector < conf->reshape_progress &&
bio->bi_iter.bi_sector + sectors > conf->reshape_progress) {
+ if (bio->bi_opf & REQ_NOWAIT) {
+ bio_wouldblock_error(bio);
+ return;
+ }
/*
* IO spans the reshape position. Need to wait for reshape to
* pass
@@ -1314,7 +1335,7 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
conf->reshape_progress <= bio->bi_iter.bi_sector ||
conf->reshape_progress >= bio->bi_iter.bi_sector +
sectors);
- wait_barrier(conf);
+ wait_barrier(conf, false);
}
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
@@ -1328,6 +1349,10 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
md_wakeup_thread(mddev->thread);
+ if (bio->bi_opf & REQ_NOWAIT) {
+ bio_wouldblock_error(bio);
+ return;
+ }
raid10_log(conf->mddev, "wait reshape metadata");
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
@@ -1337,6 +1362,10 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
if (conf->pending_count >= max_queued_requests) {
md_wakeup_thread(mddev->thread);
+ if (bio->bi_opf & REQ_NOWAIT) {
+ bio_wouldblock_error(bio);
+ return;
+ }
raid10_log(mddev, "wait queued");
wait_event(conf->wait_barrier,
conf->pending_count < max_queued_requests);
@@ -1462,9 +1491,15 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
}
}
allow_barrier(conf);
+
+ /* Don't wait for REQ_NOWAIT */
+ if (bio->bi_opf & REQ_NOWAIT) {
+ bio_wouldblock_error(bio);
+ return;
+ }
raid10_log(conf->mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
- wait_barrier(conf);
+ wait_barrier(conf, false);
goto retry_write;
}
@@ -1693,7 +1728,7 @@ static void print_conf(struct r10conf *conf)
static void close_sync(struct r10conf *conf)
{
- wait_barrier(conf);
+ wait_barrier(conf, false);
allow_barrier(conf);
mempool_destroy(conf->r10buf_pool);
@@ -4365,7 +4400,7 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
if (need_flush ||
time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
/* Need to update reshape_position in metadata */
- wait_barrier(conf);
+ wait_barrier(conf, false);
mddev->reshape_position = conf->reshape_progress;
if (mddev->reshape_backwards)
mddev->curr_resync_completed = raid10_size(mddev, 0, 0)
--
2.14.2
next prev parent reply other threads:[~2017-10-04 13:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-04 13:55 [PATCH v2 0/9] Nowait support for stacked block devices Goldwyn Rodrigues
2017-10-04 13:55 ` [PATCH 1/9] QUEUE_FLAG_NOWAIT to indicate device supports nowait Goldwyn Rodrigues
2017-10-04 13:55 ` [PATCH 2/9] md: Add nowait support to md Goldwyn Rodrigues
2017-10-04 13:55 ` [PATCH 3/9] md: raid1 nowait support Goldwyn Rodrigues
2017-10-04 13:55 ` Goldwyn Rodrigues [this message]
2017-10-04 13:55 ` [PATCH 5/9] md: raid5 " Goldwyn Rodrigues
2017-10-04 13:55 ` [PATCH 6/9] dm: add " Goldwyn Rodrigues
2017-10-04 13:55 ` [PATCH 7/9] dm: Add nowait support to raid1 Goldwyn Rodrigues
2017-10-04 13:55 ` [PATCH 8/9] dm: Add nowait support to dm-delay Goldwyn Rodrigues
2017-10-04 13:55 ` [PATCH 9/9] dm-mpath: Add nowait support Goldwyn Rodrigues
2017-10-05 17:19 ` [PATCH v2 0/9] Nowait support for stacked block devices Shaohua Li
2017-10-06 12:01 ` Goldwyn Rodrigues
2017-10-10 22:36 ` Shaohua Li
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