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From: Juan Quintela <quintela@redhat.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Cc: qemu-devel@nongnu.org,  pbonzini@redhat.com,  leobras@redhat.com,
	peterx@redhat.com,  yc-core@yandex-team.ru
Subject: Re: [PATCH 2/5] migration: never fail in global_state_store()
Date: Thu, 18 May 2023 13:18:25 +0200	[thread overview]
Message-ID: <87ilcpevlq.fsf@secure.mitica> (raw)
In-Reply-To: <20230517123752.21615-3-vsementsov@yandex-team.ru> (Vladimir Sementsov-Ogievskiy's message of "Wed, 17 May 2023 15:37:49 +0300")

Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> wrote:
> Actually global_state_store() can never fail. Let's get rid of extra
> error paths.
>
> To make things clear, use new runstate_get() and use same approach for
> global_state_store() and global_state_store_running().
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

I don't know.

On one hand, you have removed a lot of code that "can't" happen.

On the other:

> +static void global_state_do_store(RunState state)
>  {
> -    if (!runstate_store((char *)global_state.runstate,
> -                        sizeof(global_state.runstate))) {
> -        error_report("runstate name too big: %s", global_state.runstate);
> -        trace_migrate_state_too_big();
> -        return -EINVAL;
> -    }
> -    return 0;
> +    const char *state_str = RunState_str(state);
> +    assert(strlen(state_str) < sizeof(global_state.runstate));

First: g_assert() please.

Second: We try really hard not to fail during migration and get the
whole qemu back.  One assert is bad.  Specially in a place like this
one, where we know that nothing is broken, simpli that we can't migrate.

Later, Juan.



  reply	other threads:[~2023-05-18 11:18 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-17 12:37 [PATCH 0/5] Restore vmstate on cancelled/failed migration Vladimir Sementsov-Ogievskiy
2023-05-17 12:37 ` [PATCH 1/5] runstate: add runstate_get() Vladimir Sementsov-Ogievskiy
2023-05-18 11:13   ` Juan Quintela
2023-05-17 12:37 ` [PATCH 2/5] migration: never fail in global_state_store() Vladimir Sementsov-Ogievskiy
2023-05-18 11:18   ` Juan Quintela [this message]
2023-05-18 14:43     ` Vladimir Sementsov-Ogievskiy
2023-05-26  8:28   ` Juan Quintela
2023-05-17 12:37 ` [PATCH 3/5] runstate: drop unused runstate_store() Vladimir Sementsov-Ogievskiy
2023-05-18 11:19   ` Juan Quintela
2023-05-17 12:37 ` [PATCH 4/5] migration: switch from .vm_was_running to .vm_old_state Vladimir Sementsov-Ogievskiy
2023-05-18 11:20   ` Juan Quintela
2023-05-17 12:37 ` [PATCH 5/5] migration: restore vmstate on migration failure Vladimir Sementsov-Ogievskiy
2023-05-18 11:22   ` Juan Quintela
2023-05-18 11:23 ` [PATCH 0/5] Restore vmstate on cancelled/failed migration Juan Quintela
2023-05-18 14:49   ` Vladimir Sementsov-Ogievskiy
2023-05-26  7:59     ` Juan Quintela

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