From mboxrd@z Thu Jan 1 00:00:00 1970 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 7DC69C48BF6 for ; Thu, 29 Feb 2024 14:34:55 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rfhUV-0004vh-RH; Thu, 29 Feb 2024 09:34:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rfhUO-0004tq-IG for qemu-devel@nongnu.org; Thu, 29 Feb 2024 09:34:28 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rfhUM-0008Cw-Ke for qemu-devel@nongnu.org; Thu, 29 Feb 2024 09:34:24 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709217259; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=MVYHrVeU9oNfbyTSVSnir8b6q4TVAjW+f/IOg5tGrRs=; b=KP4aOs5kpiRRTcjtbeMuZiDwrp7FzGtSIsKAaa0tAmZnOgaxo0XB3nwAmffl1MVB7w5t3W grkeRjM1rnJ9NQq/YzteUhGVIFGZT/RoIfzR6EeYSAYKGDolpWgTmK3iBIJgrcXOAuo9pb 1kR/1X2Etd+gRsimL5LBqgseFNkqlQY= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-340-7RiELA5FOTaqDONbnE9eDA-1; Thu, 29 Feb 2024 09:34:16 -0500 X-MC-Unique: 7RiELA5FOTaqDONbnE9eDA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7ADBA1C05138; Thu, 29 Feb 2024 14:34:16 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.45]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 70B43C185C0; Thu, 29 Feb 2024 14:34:15 +0000 (UTC) Date: Thu, 29 Feb 2024 14:34:13 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Fabiano Rosas Cc: Peter Xu , qemu-devel@nongnu.org, armbru@redhat.com, Claudio Fontana Subject: Re: [PATCH v5 17/23] migration/multifd: Add outgoing QIOChannelFile support Message-ID: References: <20240228152127.18769-1-farosas@suse.de> <20240228152127.18769-18-farosas@suse.de> <87msrjz6ov.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87msrjz6ov.fsf@suse.de> User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.096, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Feb 29, 2024 at 11:27:44AM -0300, Fabiano Rosas wrote: > Peter Xu writes: > > > On Thu, Feb 29, 2024 at 10:44:21AM +0800, Peter Xu wrote: > >> On Wed, Feb 28, 2024 at 12:21:21PM -0300, Fabiano Rosas wrote: > >> > Allow multifd to open file-backed channels. This will be used when > >> > enabling the mapped-ram migration stream format which expects a > >> > seekable transport. > >> > > >> > The QIOChannel read and write methods will use the preadv/pwritev > >> > versions which don't update the file offset at each call so we can > >> > reuse the fd without re-opening for every channel. > >> > > >> > Contrary to the socket migration, the file migration doesn't need an > >> > asynchronous channel creation process, so expose > >> > multifd_channel_connect() and call it directly. > >> > > >> > Note that this is just setup code and multifd cannot yet make use of > >> > the file channels. > >> > > >> > Signed-off-by: Fabiano Rosas > >> > --- > >> > - moved flags change to another patch > >> > - removed channels_created assert > >> > --- > >> > migration/file.c | 41 +++++++++++++++++++++++++++++++++++++++-- > >> > migration/file.h | 4 ++++ > >> > migration/multifd.c | 18 +++++++++++++++--- > >> > migration/multifd.h | 1 + > >> > 4 files changed, 59 insertions(+), 5 deletions(-) > >> > > >> > diff --git a/migration/file.c b/migration/file.c > >> > index 22d052a71f..83328a7a1b 100644 > >> > --- a/migration/file.c > >> > +++ b/migration/file.c > >> > @@ -12,12 +12,17 @@ > >> > #include "channel.h" > >> > #include "file.h" > >> > #include "migration.h" > >> > +#include "multifd.h" > >> > #include "io/channel-file.h" > >> > #include "io/channel-util.h" > >> > #include "trace.h" > >> > > >> > #define OFFSET_OPTION ",offset=" > >> > > >> > +static struct FileOutgoingArgs { > >> > + char *fname; > >> > +} outgoing_args; > >> > + > >> > /* Remove the offset option from @filespec and return it in @offsetp. */ > >> > > >> > int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp) > >> > @@ -37,6 +42,36 @@ int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp) > >> > return 0; > >> > } > >> > > >> > +void file_cleanup_outgoing_migration(void) > >> > +{ > >> > + g_free(outgoing_args.fname); > >> > + outgoing_args.fname = NULL; > >> > +} > >> > + > >> > +bool file_send_channel_create(gpointer opaque, Error **errp) > >> > +{ > >> > + QIOChannelFile *ioc; > >> > + int flags = O_WRONLY; > >> > + bool ret = true; > >> > + > >> > + ioc = qio_channel_file_new_path(outgoing_args.fname, flags, 0, errp); > >> > + if (!ioc) { > >> > + ret = false; > >> > + goto out; > >> > + } > >> > + > >> > + multifd_channel_connect(opaque, QIO_CHANNEL(ioc)); > >> > + > >> > +out: > >> > + /* > >> > + * File channel creation is synchronous. However posting this > >> > + * semaphore here is simpler than adding a special case. > >> > + */ > >> > + multifd_send_channel_created(); > >> > + > >> > + return ret; > >> > +} > >> > + > >> > void file_start_outgoing_migration(MigrationState *s, > >> > FileMigrationArgs *file_args, Error **errp) > >> > { > >> > @@ -47,12 +82,14 @@ void file_start_outgoing_migration(MigrationState *s, > >> > > >> > trace_migration_file_outgoing(filename); > >> > > >> > - fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC, > >> > - 0600, errp); > >> > + fioc = qio_channel_file_new_path(filename, O_CREAT | O_TRUNC | O_WRONLY, > >> > + 0660, errp); > >> > >> It seems this is still leftover? > >> > >> > if (!fioc) { > >> > return; > >> > } > >> > > >> > + outgoing_args.fname = g_strdup(filename); > >> > + > >> > ioc = QIO_CHANNEL(fioc); > >> > if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) { > >> > return; > >> > diff --git a/migration/file.h b/migration/file.h > >> > index 37d6a08bfc..4577f9efdd 100644 > >> > --- a/migration/file.h > >> > +++ b/migration/file.h > >> > @@ -9,10 +9,14 @@ > >> > #define QEMU_MIGRATION_FILE_H > >> > > >> > #include "qapi/qapi-types-migration.h" > >> > +#include "io/task.h" > >> > +#include "channel.h" > >> > > >> > void file_start_incoming_migration(FileMigrationArgs *file_args, Error **errp); > >> > > >> > void file_start_outgoing_migration(MigrationState *s, > >> > FileMigrationArgs *file_args, Error **errp); > >> > int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp); > >> > +void file_cleanup_outgoing_migration(void); > >> > +bool file_send_channel_create(gpointer opaque, Error **errp); > >> > #endif > >> > diff --git a/migration/multifd.c b/migration/multifd.c > >> > index 3574fd3953..f155223303 100644 > >> > --- a/migration/multifd.c > >> > +++ b/migration/multifd.c > >> > @@ -17,6 +17,7 @@ > >> > #include "exec/ramblock.h" > >> > #include "qemu/error-report.h" > >> > #include "qapi/error.h" > >> > +#include "file.h" > >> > #include "ram.h" > >> > #include "migration.h" > >> > #include "migration-stats.h" > >> > @@ -28,6 +29,7 @@ > >> > #include "threadinfo.h" > >> > #include "options.h" > >> > #include "qemu/yank.h" > >> > +#include "io/channel-file.h" > >> > #include "io/channel-socket.h" > >> > #include "yank_functions.h" > >> > > >> > @@ -694,6 +696,7 @@ static bool multifd_send_cleanup_channel(MultiFDSendParams *p, Error **errp) > >> > { > >> > if (p->c) { > >> > migration_ioc_unregister_yank(p->c); > >> > + qio_channel_close(p->c, NULL); > >> > >> s/NULL/&error_abort/? > > > > Or we can drop this line? IIUC iochannel finalize() will always close it, > > or it could be a separate bug. > > > > We need it so the fsync happens. The finalize() will be a noop because > the qio_channel_file_close() will clear the fd. Not the cleanest, but it > works. It is always wise to explicitly call 'close'. If something still has a GSource watch registered against the QIOChannel, that GSource will be holding a reference on the QIOChannel and will thus prevent finalize() ever running. By calling close() you guarantee the channel is closed, even if you've mistakenly leaked a GSource somewhere. Finalize still won't run in that case, but at least the FD is gone, and the HUP might cause the GSource callback to trigger correct cleanup; With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|