From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60625) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dGm73-0003JY-2j for qemu-devel@nongnu.org; Fri, 02 Jun 2017 08:55:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dGm6y-00061x-6X for qemu-devel@nongnu.org; Fri, 02 Jun 2017 08:55:33 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:6982 helo=relay.sw.ru) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dGm6x-0005yh-Qm for qemu-devel@nongnu.org; Fri, 02 Jun 2017 08:55:28 -0400 References: <20170530143052.165002-1-vsementsov@virtuozzo.com> <20170530143052.165002-15-vsementsov@virtuozzo.com> <05dd8425-2773-0396-1532-e25c737c3753@redhat.com> From: Vladimir Sementsov-Ogievskiy Message-ID: <7c60e29b-6e78-7bc7-c19e-294dbf11756e@virtuozzo.com> Date: Fri, 2 Jun 2017 15:55:23 +0300 MIME-Version: 1.0 In-Reply-To: <05dd8425-2773-0396-1532-e25c737c3753@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Subject: Re: [Qemu-devel] [PATCH 14/19] nbd/server: nbd_negotiate: return 1 on NBD_OPT_ABORT List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , qemu-devel@nongnu.org Cc: pbonzini@redhat.com, den@openvz.org 02.06.2017 01:33, Eric Blake wrote: > On 05/30/2017 09:30 AM, Vladimir Sementsov-Ogievskiy wrote: >> Separate case when client sent NBD_OPT_ABORT from other errors. >> It will be needed for the following patch, where errors will be >> reported. >> Considered case is not actually the error - it honestly follows NBD >> protocol. Therefore it should not be reported like an error. >> -EPIPE case means client not read server reply on NBD_OPT_ABORT, >> which is also OK. >> >> Signed-off-by: Vladimir Sementsov-Ogievskiy >> --- >> nbd/server.c | 20 +++++++++++++++----- >> 1 file changed, 15 insertions(+), 5 deletions(-) >> >> diff --git a/nbd/server.c b/nbd/server.c >> index 30dfb81a5c..0e53d3dd91 100644 >> --- a/nbd/server.c >> +++ b/nbd/server.c >> @@ -369,9 +369,13 @@ static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client, >> return QIO_CHANNEL(tioc); >> } >> >> - >> -/* Process all NBD_OPT_* client option commands. >> - * Return -errno on error, 0 on success. */ >> +/* nbd_negotiate_options >> + * Process all NBD_OPT_* client option commands. >> + * Return: >> + * < 0 on error > Do you want to be specific that this is a negative errno value, or is it > just any negative value with no correlation to errno? nothing here (except blk_write and friends, but their errors are not returned by any function) correlates with errno, because core function - nbd_wr_syncv returns EIO on any error. Underlying io_channel returns -1 or QIO_CHANNEL_ERR_BLOCK... > >> + * 0 on successful negotiation >> + * 1 if client sent NBD_OPT_ABORT, i.e. on legal disconnect >> + */ >> static int nbd_negotiate_options(NBDClient *client) >> { >> int ret; >> @@ -483,7 +487,7 @@ static int nbd_negotiate_options(NBDClient *client) >> } >> /* Let the client keep trying, unless they asked to quit */ >> if (clientflags == NBD_OPT_ABORT) { >> - return -EINVAL; >> + return 1; >> } >> break; >> } >> @@ -502,7 +506,7 @@ static int nbd_negotiate_options(NBDClient *client) >> * guests that don't wait for our reply. */ >> ret = nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, >> clientflags); >> - return ret < 0 ? ret : -EINVAL; >> + return ret < 0 && ret != -EPIPE ? ret : 1; > This should just be 'return 1;', which means you don't need to capture > and check 'ret'. > >> >> case NBD_OPT_EXPORT_NAME: >> return nbd_negotiate_handle_export_name(client, length); >> @@ -560,6 +564,12 @@ static int nbd_negotiate_options(NBDClient *client) >> } >> } >> >> +/* nbd_negotiate >> + * Return: >> + * < 0 on error > Again, if this is reliably a negative errno, specifically document that. > >> + * 0 on successful negotiation >> + * 1 if client sent NBD_OPT_ABORT, i.e. on legal disconnect >> + */ >> static coroutine_fn int nbd_negotiate(NBDClient *client) >> { >> char buf[8 + 8 + 8 + 128]; >> -- Best regards, Vladimir