On Wed, Jul 26, 2017 at 06:58:02PM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgold...@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 <rgold...@suse.com>
> ---
> drivers/md/raid10.c | 62
> ++++++++++++++++++++++++++++++++++++++++-------------
> 1 file changed, 47 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index 5026e7ad51d3..6d80438c5040 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -978,8 +978,9 @@ 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++;
> @@ -993,19 +994,23 @@ 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;
same here, nr_pending shouldn't be increased
> conf->nr_waiting--;
> if (!conf->nr_waiting)
> wake_up(&conf->wait_barrier);
> }
> atomic_inc(&conf->nr_pending);
> spin_unlock_irq(&conf->resync_lock);
> + return ret;
> }
>
> static void allow_barrier(struct r10conf *conf)
> @@ -1158,7 +1163,10 @@ 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) &&
> @@ -1169,12 +1177,16 @@ 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);
> @@ -1308,7 +1320,10 @@ 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) &&
> @@ -1319,12 +1334,16 @@ static void raid10_write_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);
> }
>
> if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
> @@ -1339,6 +1358,10 @@ 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));
>
> @@ -1348,6 +1371,10 @@ 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);
> }
> @@ -1454,6 +1481,11 @@ static void raid10_write_request(struct mddev *mddev,
> struct bio *bio,
> int j;
> int d;
>
> + if (bio->bi_opf & REQ_NOWAIT) {
> + bio_wouldblock_error(bio);
> + return;
> + }
> +
> for (j = 0; j < i; j++) {
> if (r10_bio->devs[j].bio) {
> d = r10_bio->devs[j].devnum;
> @@ -1474,7 +1506,7 @@ static void raid10_write_request(struct mddev *mddev,
> struct bio *bio,
> allow_barrier(conf);
> 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;
> }
>
> @@ -1703,7 +1735,7 @@ 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);
> @@ -4347,7 +4379,7 @@ 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)
> --
> 2.12.3
>
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