From patchwork Tue Apr 25 17:27:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13223567 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.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 E0F2AC77B61 for ; Tue, 25 Apr 2023 17:28:10 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.526197.817831 (Exim 4.92) (envelope-from ) id 1prMSQ-0003TS-27; Tue, 25 Apr 2023 17:28:02 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 526197.817831; Tue, 25 Apr 2023 17:28:02 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1prMSP-0003QU-O7; Tue, 25 Apr 2023 17:28:01 +0000 Received: by outflank-mailman (input) for mailman id 526197; Tue, 25 Apr 2023 17:28:00 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1prMSO-0007l5-O5 for xen-devel@lists.xenproject.org; Tue, 25 Apr 2023 17:28:00 +0000 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 855969ce-e38e-11ed-8611-37d641c3527e; Tue, 25 Apr 2023 19:27:59 +0200 (CEST) Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-166-4yW8uuHRMwqs5zACvwosHQ-1; Tue, 25 Apr 2023 13:27:54 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 444E887A9E8; Tue, 25 Apr 2023 17:27:53 +0000 (UTC) Received: from localhost (unknown [10.39.193.242]) by smtp.corp.redhat.com (Postfix) with ESMTP id B7927C15BA0; Tue, 25 Apr 2023 17:27:52 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 855969ce-e38e-11ed-8611-37d641c3527e DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1682443677; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AI5kqkdzipCjtseeQPE5/aVyAJxrbcrgigA/+qZzi/8=; b=idZ+gkjmvrwYeE6c6KQnRkXUNMjTDeTpBaZZPJgqnsu9vZmQOvSnD+eemSKQjmdE1NBcme 1Ewy3ltVhx+d25ab+zfTV75mHM51VC6/j0cLXdaeocC/NZZ/+XnNGk/Yp9elP/UMUnoQNG +TGFajP/qC0wLb/1Z57F523FHGsb64g= X-MC-Unique: 4yW8uuHRMwqs5zACvwosHQ-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Juan Quintela , Julia Suvorova , Kevin Wolf , xen-devel@lists.xenproject.org, eesposit@redhat.com, Richard Henderson , Fam Zheng , "Michael S. Tsirkin" , Coiby Xu , David Woodhouse , Marcel Apfelbaum , Peter Lieven , Paul Durrant , Stefan Hajnoczi , "Richard W.M. Jones" , qemu-block@nongnu.org, Stefano Garzarella , Anthony Perard , Stefan Weil , Xie Yongji , Paolo Bonzini , Aarushi Mehta , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= , Eduardo Habkost , Stefano Stabellini , Hanna Reitz , Ronnie Sahlberg Subject: [PATCH v4 15/20] block/fuse: do not set is_external=true on FUSE fd Date: Tue, 25 Apr 2023 13:27:11 -0400 Message-Id: <20230425172716.1033562-16-stefanha@redhat.com> In-Reply-To: <20230425172716.1033562-1-stefanha@redhat.com> References: <20230425172716.1033562-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 This is part of ongoing work to remove the aio_disable_external() API. Use BlockDevOps .drained_begin/end/poll() instead of aio_set_fd_handler(is_external=true). As a side-effect the FUSE export now follows AioContext changes like the other export types. Signed-off-by: Stefan Hajnoczi --- block/export/fuse.c | 58 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 56 insertions(+), 2 deletions(-) diff --git a/block/export/fuse.c b/block/export/fuse.c index 06fa41079e..65a7f4d723 100644 --- a/block/export/fuse.c +++ b/block/export/fuse.c @@ -50,6 +50,7 @@ typedef struct FuseExport { struct fuse_session *fuse_session; struct fuse_buf fuse_buf; + unsigned int in_flight; /* atomic */ bool mounted, fd_handler_set_up; char *mountpoint; @@ -78,6 +79,42 @@ static void read_from_fuse_export(void *opaque); static bool is_regular_file(const char *path, Error **errp); +static void fuse_export_drained_begin(void *opaque) +{ + FuseExport *exp = opaque; + + aio_set_fd_handler(exp->common.ctx, + fuse_session_fd(exp->fuse_session), false, + NULL, NULL, NULL, NULL, NULL); + exp->fd_handler_set_up = false; +} + +static void fuse_export_drained_end(void *opaque) +{ + FuseExport *exp = opaque; + + /* Refresh AioContext in case it changed */ + exp->common.ctx = blk_get_aio_context(exp->common.blk); + + aio_set_fd_handler(exp->common.ctx, + fuse_session_fd(exp->fuse_session), false, + read_from_fuse_export, NULL, NULL, NULL, exp); + exp->fd_handler_set_up = true; +} + +static bool fuse_export_drained_poll(void *opaque) +{ + FuseExport *exp = opaque; + + return qatomic_read(&exp->in_flight) > 0; +} + +static const BlockDevOps fuse_export_blk_dev_ops = { + .drained_begin = fuse_export_drained_begin, + .drained_end = fuse_export_drained_end, + .drained_poll = fuse_export_drained_poll, +}; + static int fuse_export_create(BlockExport *blk_exp, BlockExportOptions *blk_exp_args, Error **errp) @@ -101,6 +138,15 @@ static int fuse_export_create(BlockExport *blk_exp, } } + blk_set_dev_ops(exp->common.blk, &fuse_export_blk_dev_ops, exp); + + /* + * We handle draining ourselves using an in-flight counter and by disabling + * the FUSE fd handler. Do not queue BlockBackend requests, they need to + * complete so the in-flight counter reaches zero. + */ + blk_set_disable_request_queuing(exp->common.blk, true); + init_exports_table(); /* @@ -224,7 +270,7 @@ static int setup_fuse_export(FuseExport *exp, const char *mountpoint, g_hash_table_insert(exports, g_strdup(mountpoint), NULL); aio_set_fd_handler(exp->common.ctx, - fuse_session_fd(exp->fuse_session), true, + fuse_session_fd(exp->fuse_session), false, read_from_fuse_export, NULL, NULL, NULL, exp); exp->fd_handler_set_up = true; @@ -246,6 +292,8 @@ static void read_from_fuse_export(void *opaque) blk_exp_ref(&exp->common); + qatomic_inc(&exp->in_flight); + do { ret = fuse_session_receive_buf(exp->fuse_session, &exp->fuse_buf); } while (ret == -EINTR); @@ -256,6 +304,10 @@ static void read_from_fuse_export(void *opaque) fuse_session_process_buf(exp->fuse_session, &exp->fuse_buf); out: + if (qatomic_fetch_dec(&exp->in_flight) == 1) { + aio_wait_kick(); /* wake AIO_WAIT_WHILE() */ + } + blk_exp_unref(&exp->common); } @@ -268,7 +320,7 @@ static void fuse_export_shutdown(BlockExport *blk_exp) if (exp->fd_handler_set_up) { aio_set_fd_handler(exp->common.ctx, - fuse_session_fd(exp->fuse_session), true, + fuse_session_fd(exp->fuse_session), false, NULL, NULL, NULL, NULL, NULL); exp->fd_handler_set_up = false; } @@ -287,6 +339,8 @@ static void fuse_export_delete(BlockExport *blk_exp) { FuseExport *exp = container_of(blk_exp, FuseExport, common); + blk_set_dev_ops(exp->common.blk, NULL, NULL); + if (exp->fuse_session) { if (exp->mounted) { fuse_session_unmount(exp->fuse_session);