From: Vishal Verma <vverma@digitalocean.com>
To: Song Liu <song@kernel.org>
Cc: linux-raid <linux-raid@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>,
rgoldwyn@suse.de
Subject: Re: [PATCH v5 3/4] md: raid10 add nowait support
Date: Wed, 15 Dec 2021 15:20:51 -0700 [thread overview]
Message-ID: <9a85af03-a551-6650-3807-c177659cd17b@digitalocean.com> (raw)
In-Reply-To: <CAPhsuW5=GLRW9g2QxgBfcx_OKq08x5GqGO4iC86x6YzDHRz8fA@mail.gmail.com>
On 12/15/21 1:42 PM, Song Liu wrote:
> On Tue, Dec 14, 2021 at 10:09 PM Vishal Verma <vverma@digitalocean.com> wrote:
>> This adds nowait support to the RAID10 driver. Very similar to
>> raid1 driver changes. It makes RAID10 driver return with EAGAIN
>> for situations where it could wait for eg:
>>
>> - Waiting for the barrier,
>> - Too many pending I/Os to be queued,
>> - Reshape operation,
>> - Discard operation.
>>
>> wait_barrier() fn is modified to return bool to support error for
>> wait barriers. It returns true in case of wait or if wait is not
>> required and returns false if wait was required but not performed
>> to support nowait.
>>
>> Signed-off-by: Vishal Verma <vverma@digitalocean.com>
>> ---
>> drivers/md/raid10.c | 57 +++++++++++++++++++++++++++++++++++----------
>> 1 file changed, 45 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
>> index dde98f65bd04..f6c73987e9ac 100644
>> --- a/drivers/md/raid10.c
>> +++ b/drivers/md/raid10.c
>> @@ -952,11 +952,18 @@ 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)
>> {
>> spin_lock_irq(&conf->resync_lock);
>> if (conf->barrier) {
>> struct bio_list *bio_list = current->bio_list;
>> +
>> + /* Return false when nowait flag is set */
>> + if (nowait) {
>> + spin_unlock_irq(&conf->resync_lock);
>> + return false;
>> + }
>> +
>> conf->nr_waiting++;
>> /* Wait for the barrier to drop.
>> * However if there are already pending
>> @@ -988,6 +995,7 @@ static void wait_barrier(struct r10conf *conf)
>> }
>> atomic_inc(&conf->nr_pending);
>> spin_unlock_irq(&conf->resync_lock);
>> + return true;
>> }
>>
>> static void allow_barrier(struct r10conf *conf)
>> @@ -1101,17 +1109,25 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
>> static void regular_request_wait(struct mddev *mddev, struct r10conf *conf,
>> struct bio *bio, sector_t sectors)
>> {
>> - wait_barrier(conf);
>> + /* Bail out if REQ_NOWAIT is set for the bio */
>> + if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) {
>> + bio_wouldblock_error(bio);
>> + return;
>> + }
> I think we also need regular_request_wait to return bool and handle it properly.
>
> Thanks,
> Song
>
Ack, will fix it. Thanks!
>> 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) {
>> 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);
>> }
>> }
>>
>> @@ -1179,7 +1195,7 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
>> bio_chain(split, bio);
>> allow_barrier(conf);
>> submit_bio_noacct(bio);
>> - wait_barrier(conf);
>> + wait_barrier(conf, false);
>> bio = split;
>> r10_bio->master_bio = bio;
>> r10_bio->sectors = max_sectors;
>> @@ -1338,7 +1354,7 @@ static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
>> raid10_log(conf->mddev, "%s wait rdev %d blocked",
>> __func__, blocked_rdev->raid_disk);
>> md_wait_for_blocked_rdev(blocked_rdev, mddev);
>> - wait_barrier(conf);
>> + wait_barrier(conf, false);
>> goto retry_wait;
>> }
>> }
>> @@ -1357,6 +1373,11 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
>> bio_end_sector(bio)))) {
>> DEFINE_WAIT(w);
>> for (;;) {
>> + /* Bail out if REQ_NOWAIT is set for the bio */
>> + if (bio->bi_opf & REQ_NOWAIT) {
>> + bio_wouldblock_error(bio);
>> + return;
>> + }
>> prepare_to_wait(&conf->wait_barrier,
>> &w, TASK_IDLE);
>> if (!md_cluster_ops->area_resyncing(mddev, WRITE,
>> @@ -1381,6 +1402,10 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
>> BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
>> md_wakeup_thread(mddev->thread);
>> raid10_log(conf->mddev, "wait reshape metadata");
>> + if (bio->bi_opf & REQ_NOWAIT) {
>> + bio_wouldblock_error(bio);
>> + return;
>> + }
>> wait_event(mddev->sb_wait,
>> !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
>>
>> @@ -1390,6 +1415,10 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
>> if (conf->pending_count >= max_queued_requests) {
>> md_wakeup_thread(mddev->thread);
>> raid10_log(mddev, "wait queued");
>> + if (bio->bi_opf & REQ_NOWAIT) {
>> + bio_wouldblock_error(bio);
>> + return;
>> + }
>> wait_event(conf->wait_barrier,
>> conf->pending_count < max_queued_requests);
>> }
>> @@ -1482,7 +1511,7 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
>> bio_chain(split, bio);
>> allow_barrier(conf);
>> submit_bio_noacct(bio);
>> - wait_barrier(conf);
>> + wait_barrier(conf, false);
>> bio = split;
>> r10_bio->master_bio = bio;
>> }
>> @@ -1607,7 +1636,11 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
>> if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
>> return -EAGAIN;
>>
>> - wait_barrier(conf);
>> + if (bio->bi_opf & REQ_NOWAIT) {
>> + bio_wouldblock_error(bio);
>> + return 0;
>> + }
>> + wait_barrier(conf, false);
>>
>> /*
>> * Check reshape again to avoid reshape happens after checking
>> @@ -1649,7 +1682,7 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
>> allow_barrier(conf);
>> /* Resend the fist split part */
>> submit_bio_noacct(split);
>> - wait_barrier(conf);
>> + wait_barrier(conf, false);
>> }
>> div_u64_rem(bio_end, stripe_size, &remainder);
>> if (remainder) {
>> @@ -1660,7 +1693,7 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
>> /* Resend the second split part */
>> submit_bio_noacct(bio);
>> bio = split;
>> - wait_barrier(conf);
>> + wait_barrier(conf, false);
>> }
>>
>> bio_start = bio->bi_iter.bi_sector;
>> @@ -1816,7 +1849,7 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
>> end_disk_offset += geo->stride;
>> atomic_inc(&first_r10bio->remaining);
>> raid_end_discard_bio(r10_bio);
>> - wait_barrier(conf);
>> + wait_barrier(conf, false);
>> goto retry_discard;
>> }
>>
>> @@ -2011,7 +2044,7 @@ 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_exit(&conf->r10buf_pool);
>> @@ -4819,7 +4852,7 @@ 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)
>> --
>> 2.17.1
>>
next prev parent reply other threads:[~2021-12-15 22:20 UTC|newest]
Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-01 21:51 [PATCH] md: add support for REQ_NOWAIT Vishal Verma
2021-11-02 3:41 ` Li Feng
2021-11-02 5:01 ` Song Liu
2021-11-02 14:40 ` [PATCH v2] " Vishal Verma
2021-11-02 15:31 ` Jens Axboe
2021-11-02 18:35 ` Song Liu
2021-11-04 4:51 ` [PATCH v3 2/2] md: raid1 add nowait support Vishal Verma
2021-11-04 4:51 ` [PATCH v3 1/2] md: add support for REQ_NOWAIT Vishal Verma
2021-11-06 15:38 ` Guoqing Jiang
2021-11-07 0:16 ` Vishal Verma
2021-11-08 22:17 ` Song Liu
2021-11-08 22:36 ` Vishal Verma
2021-11-06 15:24 ` [PATCH v3 2/2] md: raid1 add nowait support Guoqing Jiang
2021-11-07 0:18 ` Vishal Verma
2021-11-08 22:32 ` Song Liu
2021-11-08 22:39 ` Vishal Verma
2021-11-09 20:59 ` Vishal Verma
2021-11-10 17:02 ` Song Liu
2021-11-10 17:04 ` Vishal Verma
2021-11-10 18:14 ` [RFC PATCH v4 1/4] md: add support for REQ_NOWAIT Vishal Verma
2021-11-10 18:14 ` [RFC PATCH v4 2/4] md: raid1 add nowait support Vishal Verma
2021-11-10 18:14 ` [RFC PATCH v4 3/4] md: raid10 " Vishal Verma
2021-12-14 0:32 ` Song Liu
2021-12-14 15:27 ` Vishal Verma
2021-11-10 18:14 ` [RFC PATCH v4 4/4] md: raid456 " Vishal Verma
2021-11-11 21:42 ` Song Liu
[not found] ` <f8c2a2bc-a885-8254-2b39-fc0c969ac70d@digitalocean.com>
2021-11-19 4:07 ` Song Liu
2021-11-19 4:20 ` Vishal Verma
2021-12-09 16:53 ` Vishal Verma
2021-12-09 16:59 ` Song Liu
2021-12-09 17:01 ` Vishal Verma
2021-12-10 2:16 ` Song Liu
2021-12-10 7:18 ` Song Liu
2021-12-10 18:26 ` Vishal Verma
2021-12-13 5:56 ` Song Liu
2021-12-13 22:43 ` Vishal Verma
2021-12-13 23:35 ` Jens Axboe
[not found] ` <78d5f029-791e-6d3f-4871-263ec6b5c09b@digitalocean.com>
2021-12-14 1:11 ` Song Liu
2021-12-14 1:12 ` Vishal Verma
2021-12-14 15:30 ` Vishal Verma
2021-12-14 17:08 ` Song Liu
2021-12-14 18:09 ` Vishal Verma
2021-12-15 6:09 ` [PATCH v5 1/4] md: add support for REQ_NOWAIT Vishal Verma
2021-12-15 6:09 ` [PATCH v5 2/4] md: raid1 add nowait support Vishal Verma
2021-12-15 20:33 ` Song Liu
2021-12-15 22:20 ` Vishal Verma
2021-12-21 20:06 ` [PATCH v6 1/4] md: add support for REQ_NOWAIT Vishal Verma
2021-12-21 20:06 ` [PATCH v6 2/4] md: raid1 add nowait support Vishal Verma
2021-12-21 20:06 ` [PATCH v6 3/4] md: raid10 " Vishal Verma
2021-12-22 23:58 ` Song Liu
2021-12-23 1:47 ` Song Liu
2021-12-21 20:06 ` [PATCH v6 4/4] md: raid456 " Vishal Verma
2021-12-21 22:02 ` John Stoffel
2021-12-25 2:14 ` Song Liu
[not found] ` <aadc6d52-bc6e-527a-3b9c-0be225f9b727@digitalocean.com>
2021-12-25 22:13 ` Vishal Verma
2021-12-26 0:07 ` Song Liu
2021-12-26 4:02 ` Vishal Verma
2021-12-26 21:20 ` Vishal Verma
2021-12-22 16:06 ` [PATCH v6 1/4] md: add support for REQ_NOWAIT Jens Axboe
2021-12-23 1:22 ` Song Liu
2021-12-23 2:57 ` Song Liu
2021-12-23 3:08 ` Vishal Verma
2022-01-02 0:11 ` Song Liu
2022-01-02 2:08 ` Vishal Verma
2021-12-23 8:36 ` Christoph Hellwig
2021-12-15 6:09 ` [PATCH v5 3/4] md: raid10 add nowait support Vishal Verma
2021-12-15 20:42 ` Song Liu
2021-12-15 22:20 ` Vishal Verma [this message]
2021-12-16 0:30 ` Vishal Verma
2021-12-16 16:40 ` Vishal Verma
2021-12-16 16:42 ` Jens Axboe
2021-12-16 16:45 ` Vishal Verma
2021-12-16 18:49 ` Jens Axboe
2021-12-16 19:40 ` Vishal Verma
2021-12-16 20:18 ` Song Liu
2021-12-16 20:37 ` Vishal Verma
2021-12-16 23:50 ` Song Liu
[not found] ` <bd90d6e6-adb4-2696-3110-fad0b1ee00dc@digitalocean.com>
2021-12-21 8:13 ` Song Liu
2021-12-21 15:29 ` Vishal Verma
2021-12-21 15:59 ` Jens Axboe
2021-12-21 16:26 ` Vishal Verma
2021-12-16 18:14 ` Vishal Verma
2021-12-15 6:09 ` [PATCH v5 4/4] md: raid456 " Vishal Verma
2021-12-15 20:02 ` [PATCH v5 1/4] md: add support for REQ_NOWAIT Song Liu
2021-12-14 0:36 ` [RFC PATCH v4 4/4] md: raid456 add nowait support Song Liu
2021-12-13 23:50 ` [RFC PATCH v4 1/4] md: add support for REQ_NOWAIT Song Liu
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