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md/raid5: Refactor raid5_get_active_stripe()

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

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
This commit is contained in:
Logan Gunthorpe 2022-08-11 11:14:14 -06:00 committed by Song Liu
parent 1727fd5015
commit b6d56144fe
1 changed files with 43 additions and 43 deletions
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86
drivers/md/raid5.c
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@ -811,54 +811,54 @@ static struct stripe_head *__raid5_get_active_stripe(struct r5conf *conf,
spin_lock_irq(conf->hash_locks + hash);
retry:
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.
*/
if (ctx && ctx->batch_last) {
raid5_release_stripe(ctx->batch_last);
ctx->batch_last = NULL;
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.
*/
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,
*(conf->hash_locks + hash));
}
wait_event_lock_irq(conf->wait_for_quiescent, !conf->quiesce,
sh = find_get_stripe(conf, sector, conf->generation - previous,
hash);
if (sh)
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);
break;
}
if (!test_bit(R5_DID_ALLOC, &conf->cache_state))
set_bit(R5_ALLOC_MORE, &conf->cache_state);
}
if (noblock)
break;
set_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
r5l_wake_reclaim(conf->log, 0);
wait_event_lock_irq(conf->wait_for_stripe,
is_inactive_blocked(conf, hash),
*(conf->hash_locks + hash));
clear_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
}
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;
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;
}
if (!test_bit(R5_DID_ALLOC, &conf->cache_state))
set_bit(R5_ALLOC_MORE, &conf->cache_state);
wait_for_stripe:
if (noblock)
goto out;
set_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
r5l_wake_reclaim(conf->log, 0);
wait_event_lock_irq(conf->wait_for_stripe,
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;
}