From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O9f44-0000Hf-Db for qemu-devel@nongnu.org; Wed, 05 May 2010 09:55:04 -0400 Received: from [140.186.70.92] (port=54998 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O9f42-0000FW-QZ for qemu-devel@nongnu.org; Wed, 05 May 2010 09:55:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O9f41-0008QS-DG for qemu-devel@nongnu.org; Wed, 05 May 2010 09:55:02 -0400 Received: from mail-yw0-f198.google.com ([209.85.211.198]:62858) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O9f41-0008QN-9e for qemu-devel@nongnu.org; Wed, 05 May 2010 09:55:01 -0400 Received: by ywh36 with SMTP id 36so2209907ywh.4 for ; Wed, 05 May 2010 06:55:00 -0700 (PDT) Message-ID: <4BE178A8.8000600@codemonkey.ws> Date: Wed, 05 May 2010 08:54:48 -0500 From: Anthony Liguori MIME-Version: 1.0 References: <1273009170-17530-1-git-send-email-amit.shah@redhat.com> <1273009170-17530-2-git-send-email-amit.shah@redhat.com> <1273009170-17530-3-git-send-email-amit.shah@redhat.com> <1273009170-17530-4-git-send-email-amit.shah@redhat.com> <4BE16F67.6070901@codemonkey.ws> <20100505132347.GB27194@amit-x200.redhat.com> In-Reply-To: <20100505132347.GB27194@amit-x200.redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH v7 3/6] char: Let writers know how much data was written in case of errors List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Amit Shah Cc: Paul Brook , Juan Quintela , qemu list , Gerd Hoffmann On 05/05/2010 08:23 AM, Amit Shah wrote: > On (Wed) May 05 2010 [08:15:19], Anthony Liguori wrote: > >> On 05/04/2010 04:39 PM, Amit Shah wrote: >> >>> On writing errors, we just returned -1 even if some bytes were already >>> written out. Ensure we return the number of bytes written before we >>> return the error (on a subsequent call to qemu_chr_write()). >>> >>> Signed-off-by: Amit Shah >>> --- >>> qemu-char.c | 12 +++++++++++- >>> 1 files changed, 11 insertions(+), 1 deletions(-) >>> >>> diff --git a/qemu-char.c b/qemu-char.c >>> index 76ad12c..decf687 100644 >>> --- a/qemu-char.c >>> +++ b/qemu-char.c >>> @@ -507,6 +507,9 @@ int send_all(int fd, const void *buf, int len1) >>> while (len> 0) { >>> ret = send(fd, buf, len, 0); >>> if (ret< 0) { >>> + if (len1 - len) { >>> + return len1 - len; >>> + } >>> errno = WSAGetLastError(); >>> if (errno != WSAEWOULDBLOCK) { >>> return -1; >>> @@ -531,8 +534,15 @@ static int unix_write(int fd, const uint8_t *buf, int len1) >>> while (len> 0) { >>> ret = write(fd, buf, len); >>> if (ret< 0) { >>> - if (errno != EINTR&& errno != EAGAIN) >>> + if (errno == EINTR) { >>> + continue; >>> + } >>> + if (len1 - len) { >>> + return len1 - len; >>> + } >>> + if (errno != EAGAIN) { >>> return -1; >>> + } >>> } else if (ret == 0) { >>> break; >>> } else { >>> >>> >> This will break lots of things. The contract for send_all and >> unix_write is that the transmit all data. >> > The current behaviour remains unchanged for all the users. Only callers > of qemu_chr_write_nb() will get an -EAGAIN return. > No, send_all used to send all data. After your change, it only sends what it can the first time. The same with unix_write. Regards, Anthony Liguori > Amit >