From patchwork Mon Feb 14 13:58:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 12745737 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6CB17C433EF for ; Mon, 14 Feb 2022 15:37:22 +0000 (UTC) Received: from localhost ([::1]:58152 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nJdPl-0001zo-Bm for qemu-devel@archiver.kernel.org; Mon, 14 Feb 2022 10:37:21 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40624) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nJbu4-0006mD-3D for qemu-devel@nongnu.org; Mon, 14 Feb 2022 09:00:32 -0500 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:32826) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nJbu2-0002QD-6f for qemu-devel@nongnu.org; Mon, 14 Feb 2022 09:00:31 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-108-iYdiRZBtNpmmfswym7P7iA-1; Mon, 14 Feb 2022 09:00:25 -0500 X-MC-Unique: iYdiRZBtNpmmfswym7P7iA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9E261189DF42; Mon, 14 Feb 2022 14:00:24 +0000 (UTC) Received: from bahia.redhat.com (unknown [10.39.192.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id E83266ABB9; Mon, 14 Feb 2022 13:59:51 +0000 (UTC) From: Greg Kurz To: qemu-devel@nongnu.org Subject: [PATCH v5 3/3] virtiofsd: Add support for FUSE_SYNCFS request without announce_submounts Date: Mon, 14 Feb 2022 14:58:20 +0100 Message-Id: <20220214135820.43897-4-groug@kaod.org> In-Reply-To: <20220214135820.43897-1-groug@kaod.org> References: <20220214135820.43897-1-groug@kaod.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=groug@kaod.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kaod.org Received-SPF: softfail client-ip=205.139.111.44; envelope-from=groug@kaod.org; helo=us-smtp-delivery-44.mimecast.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sebastian Hasler , "Dr. David Alan Gilbert" , Greg Kurz , virtio-fs@redhat.com, Stefan Hajnoczi , Vivek Goyal Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This adds the missing bits to support FUSE_SYNCFS in the case submounts aren't announced to the client. Iterate over all inodes and call syncfs() on the ones marked as submounts. Since syncfs() can block for an indefinite time, we cannot call it with lo->mutex held as it would prevent the server to process other requests. This is thus broken down in two steps. First build a list of submounts with lo->mutex held, drop the mutex and finally process the list. A reference is taken on the inodes to ensure they don't go away when lo->mutex is dropped. Signed-off-by: Greg Kurz --- tools/virtiofsd/passthrough_ll.c | 38 ++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index e94c4e6f8635..7ce944bfe2a0 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -3400,8 +3400,42 @@ static void lo_syncfs(fuse_req_t req, fuse_ino_t ino) err = lo_do_syncfs(lo, inode); lo_inode_put(lo, &inode); } else { - /* Requires the sever to track submounts. Not implemented yet */ - err = ENOSYS; + g_autoptr(GSList) submount_list = NULL; + GSList *elem; + GHashTableIter iter; + gpointer key, value; + + pthread_mutex_lock(&lo->mutex); + + g_hash_table_iter_init(&iter, lo->inodes); + while (g_hash_table_iter_next(&iter, &key, &value)) { + struct lo_inode *inode = value; + + if (inode->is_submount) { + g_atomic_int_inc(&inode->refcount); + submount_list = g_slist_prepend(submount_list, inode); + } + } + + pthread_mutex_unlock(&lo->mutex); + + /* The root inode is always present and not tracked in the hash table */ + err = lo_do_syncfs(lo, &lo->root); + + for (elem = submount_list; elem; elem = g_slist_next(elem)) { + struct lo_inode *inode = elem->data; + int r; + + r = lo_do_syncfs(lo, inode); + if (r) { + /* + * Try to sync as much as possible. Only one error can be + * reported to the client though, arbitrarily the last one. + */ + err = r; + } + lo_inode_put(lo, &inode); + } } fuse_reply_err(req, err);