From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58846) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fGNDY-00052E-VT for qemu-devel@nongnu.org; Wed, 09 May 2018 07:25:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fGNDX-0001s6-9r for qemu-devel@nongnu.org; Wed, 09 May 2018 07:25:08 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60862 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fGNDX-0001qp-44 for qemu-devel@nongnu.org; Wed, 09 May 2018 07:25:07 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C065D406C758 for ; Wed, 9 May 2018 11:25:06 +0000 (UTC) From: Juan Quintela Date: Wed, 9 May 2018 13:24:00 +0200 Message-Id: <20180509112406.6183-36-quintela@redhat.com> In-Reply-To: <20180509112406.6183-1-quintela@redhat.com> References: <20180509112406.6183-1-quintela@redhat.com> Subject: [Qemu-devel] [PULL 35/41] migration: introduce lock for to_dst_file List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: dgilbert@redhat.com, lvivier@redhat.com, peterx@redhat.com From: Peter Xu Let's introduce a lock for that QEMUFile since we are going to operate on it in multiple threads. Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Peter Xu Message-Id: <20180502104740.12123-23-peterx@redhat.com> Signed-off-by: Juan Quintela --- migration/channel.c | 3 ++- migration/migration.c | 22 +++++++++++++++++++--- migration/migration.h | 6 ++++++ 3 files changed, 27 insertions(+), 4 deletions(-) diff --git a/migration/channel.c b/migration/channel.c index c5eaf0fa0e..716192bf75 100644 --- a/migration/channel.c +++ b/migration/channel.c @@ -74,8 +74,9 @@ void migration_channel_connect(MigrationState *s, } else { QEMUFile *f = qemu_fopen_channel_output(ioc); + qemu_mutex_lock(&s->qemu_file_lock); s->to_dst_file = f; - + qemu_mutex_unlock(&s->qemu_file_lock); } } migrate_fd_connect(s, error); diff --git a/migration/migration.c b/migration/migration.c index 1beb5e07fb..3deded90e5 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1234,6 +1234,7 @@ static void migrate_fd_cleanup(void *opaque) if (s->to_dst_file) { Error *local_err = NULL; + QEMUFile *tmp; trace_migrate_fd_cleanup(); qemu_mutex_unlock_iothread(); @@ -1246,8 +1247,15 @@ static void migrate_fd_cleanup(void *opaque) if (multifd_save_cleanup(&local_err) != 0) { error_report_err(local_err); } - qemu_fclose(s->to_dst_file); + qemu_mutex_lock(&s->qemu_file_lock); + tmp = s->to_dst_file; s->to_dst_file = NULL; + qemu_mutex_unlock(&s->qemu_file_lock); + /* + * Close the file handle without the lock to make sure the + * critical section won't block for long. + */ + qemu_fclose(tmp); } assert((s->state != MIGRATION_STATUS_ACTIVE) && @@ -2531,14 +2539,20 @@ static MigThrError postcopy_pause(MigrationState *s) assert(s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); while (true) { + QEMUFile *file; + migrate_set_state(&s->state, s->state, MIGRATION_STATUS_POSTCOPY_PAUSED); /* Current channel is possibly broken. Release it. */ assert(s->to_dst_file); - qemu_file_shutdown(s->to_dst_file); - qemu_fclose(s->to_dst_file); + qemu_mutex_lock(&s->qemu_file_lock); + file = s->to_dst_file; s->to_dst_file = NULL; + qemu_mutex_unlock(&s->qemu_file_lock); + + qemu_file_shutdown(file); + qemu_fclose(file); error_report("Detected IO failure for postcopy. " "Migration paused."); @@ -3007,6 +3021,7 @@ static void migration_instance_finalize(Object *obj) MigrationParameters *params = &ms->parameters; qemu_mutex_destroy(&ms->error_mutex); + qemu_mutex_destroy(&ms->qemu_file_lock); g_free(params->tls_hostname); g_free(params->tls_creds); qemu_sem_destroy(&ms->pause_sem); @@ -3046,6 +3061,7 @@ static void migration_instance_init(Object *obj) qemu_sem_init(&ms->postcopy_pause_sem, 0); qemu_sem_init(&ms->postcopy_pause_rp_sem, 0); qemu_sem_init(&ms->rp_state.rp_sem, 0); + qemu_mutex_init(&ms->qemu_file_lock); } /* diff --git a/migration/migration.h b/migration/migration.h index f83f1064b5..8f0c82159b 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -114,6 +114,12 @@ struct MigrationState QemuThread thread; QEMUBH *cleanup_bh; QEMUFile *to_dst_file; + /* + * Protects to_dst_file pointer. We need to make sure we won't + * yield or hang during the critical section, since this lock will + * be used in OOB command handler. + */ + QemuMutex qemu_file_lock; /* bytes already send at the beggining of current interation */ uint64_t iteration_initial_bytes; -- 2.17.0