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bh=dqnDTZrNodWjgcuLyV9KwUrxGrsW6aL6wUkxskQX4JU=; b=Yzl/5ZyFU2lDasnjJ9PpFEKriLDD4nftF8zZyYO5D8csF7iCsGuObjjcoUD8luG0P42LrX t8lNdgA6ddolykapSVH1a1dvfECr7D1lIThunqyzvwtZx2A2twRrAVcraPDI8eyEfwFHNA GBgXihKwhEB+QEHG4VYXpB6RGU+EpNM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-551--icnRImIPkyIBNa3Me5iWw-1; Mon, 04 Jan 2021 10:17:26 -0500 X-MC-Unique: -icnRImIPkyIBNa3Me5iWw-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 F2829107ACE6; Mon, 4 Jan 2021 15:17:23 +0000 (UTC) Received: from redhat.com (ovpn-114-43.ams2.redhat.com [10.36.114.43]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0E27E5C8AA; Mon, 4 Jan 2021 15:16:56 +0000 (UTC) Date: Mon, 4 Jan 2021 15:16:53 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: elena.ufimtseva@oracle.com Subject: Re: [PATCH v15 08/20] multi-process: add qio channel read function Message-ID: <20210104151653.GM640208@redhat.com> References: <42569c768066e334186ea8567847d96c8ebb0ad9.1608702853.git.elena.ufimtseva@oracle.com> MIME-Version: 1.0 In-Reply-To: <42569c768066e334186ea8567847d96c8ebb0ad9.1608702853.git.elena.ufimtseva@oracle.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.243, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: fam@euphon.net, john.g.johnson@oracle.com, swapnil.ingle@nutanix.com, mst@redhat.com, qemu-devel@nongnu.org, kraxel@redhat.com, jag.raman@oracle.com, quintela@redhat.com, armbru@redhat.com, kanth.ghatraju@oracle.com, felipe@nutanix.com, thuth@redhat.com, ehabkost@redhat.com, konrad.wilk@oracle.com, dgilbert@redhat.com, alex.williamson@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, kwolf@redhat.com, mreitz@redhat.com, ross.lagerwall@citrix.com, marcandre.lureau@gmail.com, thanos.makatos@nutanix.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Dec 22, 2020 at 10:14:43PM -0800, elena.ufimtseva@oracle.com wrote: > From: Elena Ufimtseva > > Adds qio_channel_readv_full_all() to read both data and FDs. > Refactors existing code to use this function. > > Signed-off-by: Elena Ufimtseva > Signed-off-by: John G Johnson > Signed-off-by: Jagannathan Raman > --- > include/io/channel.h | 25 +++++++++++++ > io/channel.c | 85 +++++++++++++++++++++++++++++++------------- > 2 files changed, 85 insertions(+), 25 deletions(-) > > diff --git a/include/io/channel.h b/include/io/channel.h > index 2378567d4b..429ece9a05 100644 > --- a/include/io/channel.h > +++ b/include/io/channel.h > @@ -774,6 +774,31 @@ void qio_channel_set_aio_fd_handler(QIOChannel *ioc, > IOHandler *io_write, > void *opaque); > > +/** > + * qio_channel_readv_full_all: > + * @ioc: the channel object > + * @iov: the array of memory regions to read data to > + * @niov: the length of the @iov array > + * @fds: an array of file handles to read > + * @nfds: number of file handles in @fds > + * @errp: pointer to a NULL-initialized error object > + * > + * > + * Behaves like qio_channel_readv_full but will attempt > + * to read all data specified (file handles and memory regions). > + * The function will wait for all requested data > + * to be read, yielding from the current coroutine > + * if required. > + * > + * Returns: 0 if all bytes were read, or -1 on error > + */ > + > +int qio_channel_readv_full_all(QIOChannel *ioc, > + const struct iovec *iov, > + size_t niov, > + int **fds, size_t *nfds, > + Error **errp); There parameters are one character mis-aligned here. > diff --git a/io/channel.c b/io/channel.c > index bde1f6d0f4..5edaea1fac 100644 > --- a/io/channel.c > +++ b/io/channel.c > @@ -91,11 +91,49 @@ int qio_channel_readv_all_eof(QIOChannel *ioc, > const struct iovec *iov, > size_t niov, > Error **errp) > +{ > + int ret = qio_channel_readv_full_all(ioc, iov, niov, NULL, NULL, errp); > + > + if (ret == -ECANCELED) { > + error_prepend(errp, > + "Unexpected end-of-file before all bytes were read: "); > + ret = -1; > + } > + > + return ret; > +} > + > +int qio_channel_readv_all(QIOChannel *ioc, > + const struct iovec *iov, > + size_t niov, > + Error **errp) > +{ > + int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp); > + > + if (ret == 0) { > + error_setg(errp, > + "Unexpected end-of-file before all bytes were read"); > + return -1; > + } > + if (ret == 1) { > + return 0; > + } > + > + return ret; > +} > + > +int qio_channel_readv_full_all(QIOChannel *ioc, > + const struct iovec *iov, > + size_t niov, > + int **fds, size_t *nfds, > + Error **errp) > { > int ret = -1; > struct iovec *local_iov = g_new(struct iovec, niov); > struct iovec *local_iov_head = local_iov; > unsigned int nlocal_iov = niov; > + int **local_fds = fds; > + size_t *local_nfds = nfds; It doesn't look like we actually need these as local variables, as opposed to just replacing the parameters. > bool partial = false; > > nlocal_iov = iov_copy(local_iov, nlocal_iov, > @@ -104,7 +142,8 @@ int qio_channel_readv_all_eof(QIOChannel *ioc, > > while (nlocal_iov > 0) { > ssize_t len; > - len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp); > + len = qio_channel_readv_full(ioc, local_iov, nlocal_iov, local_fds, > + local_nfds, errp); > if (len == QIO_CHANNEL_ERR_BLOCK) { > if (qemu_in_coroutine()) { > qio_channel_yield(ioc, G_IO_IN); > @@ -112,20 +151,33 @@ int qio_channel_readv_all_eof(QIOChannel *ioc, > qio_channel_wait(ioc, G_IO_IN); > } > continue; > - } else if (len < 0) { > - goto cleanup; > - } else if (len == 0) { > - if (partial) { > - error_setg(errp, > - "Unexpected end-of-file before all bytes were read"); > + } > + > + if (len <= 0) { > + size_t fd_idx = nfds ? *nfds : 0; > + if (partial && (len == 0)) { > + ret = -ECANCELED; As Marc-Andre mentioned, we intentionally avoid returning 'errno' from any of the QIO functions, so I definitely don't want to see this added. If I look at the current set of APIs: qio_channel_readv_full qio_channel_readv qio_channel_readv_all qio_channel_readv_all_eof qio_channel_read qio_channel_read_all qio_channel_read_all_eof I think the problem is that you're introducing just 1 new function, when we really should have two in order to complete the code pattern we have. ie qio_channel_readv_full_all qio_channel_readv_full_all_eof the former should call the latter. > } else { > - ret = 0; > + ret = len; > + } > + > + while (fds && fd_idx) { > + close(*fds[fd_idx - 1]); > + fd_idx--; > + } > + > + if (fds) { > + g_free(*fds); > } > + > goto cleanup; > } > > partial = true; > iov_discard_front(&local_iov, &nlocal_iov, len); > + > + local_fds = NULL; > + local_nfds = 0; > } > > ret = 1; > @@ -135,23 +187,6 @@ int qio_channel_readv_all_eof(QIOChannel *ioc, > return ret; > } > > -int qio_channel_readv_all(QIOChannel *ioc, > - const struct iovec *iov, > - size_t niov, > - Error **errp) > -{ > - int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp); > - > - if (ret == 0) { > - ret = -1; > - error_setg(errp, > - "Unexpected end-of-file before all bytes were read"); > - } else if (ret == 1) { > - ret = 0; > - } > - return ret; > -} > - Try not to mix in code movement with functional changes, as it obscures the diffs. IOW, if you want to re-arrange funtions in the file, do this as a separate patch first. 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 :|