Commit b6d56144 authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Song Liu
Browse files

md/raid5: Refactor raid5_get_active_stripe() 



Refactor raid5_get_active_stripe() without the gotos with an
explicit infinite loop and some additional nesting.

Suggested-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarSong Liu <song@kernel.org>
parent 1727fd50

drivers/md/raid5.c

+41 −41
Original line number Diff line number Diff line
@@ -811,44 +811,45 @@ static struct stripe_head *__raid5_get_active_stripe(struct r5conf *conf, 


	spin_lock_irq(conf->hash_locks + hash);



retry:

	for (;;) {

		if (!noquiesce && conf->quiesce) {

			/*

		 * Must release the reference to batch_last before waiting,

		 * on quiesce, otherwise the batch_last will hold a reference

		 * to a stripe and raid5_quiesce() will deadlock waiting for

		 * active_stripes to go to zero.

			 * Must release the reference to batch_last before

			 * waiting, on quiesce, otherwise the batch_last will

			 * hold a reference to a stripe and raid5_quiesce()

			 * will deadlock waiting for active_stripes to go to

			 * zero.

			 */

			if (ctx && ctx->batch_last) {

				raid5_release_stripe(ctx->batch_last);

				ctx->batch_last = NULL;

			}



		wait_event_lock_irq(conf->wait_for_quiescent, !conf->quiesce,

			wait_event_lock_irq(conf->wait_for_quiescent,

					    !conf->quiesce,

					    *(conf->hash_locks + hash));

		}



	sh = find_get_stripe(conf, sector, conf->generation - previous, hash);

		sh = find_get_stripe(conf, sector, conf->generation - previous,

				     hash);

		if (sh)

		goto out;



	if (test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))

		goto wait_for_stripe;

			break;



		if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) {

			sh = get_free_stripe(conf, hash);

			if (sh) {

				r5c_check_stripe_cache_usage(conf);

				init_stripe(sh, sector, previous);

				atomic_inc(&sh->count);

		goto out;

				break;

			}



			if (!test_bit(R5_DID_ALLOC, &conf->cache_state))

				set_bit(R5_ALLOC_MORE, &conf->cache_state);

		}



wait_for_stripe:

		if (noblock)

		goto out;

			break;



		set_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);

		r5l_wake_reclaim(conf->log, 0);
@@ -856,9 +857,8 @@ static struct stripe_head *__raid5_get_active_stripe(struct r5conf *conf, 
				    is_inactive_blocked(conf, hash),

				    *(conf->hash_locks + hash));

		clear_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);

	goto retry;

	}



out:

	spin_unlock_irq(conf->hash_locks + hash);

	return sh;

}