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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 11 Jul 2019 20:42:03 +0100 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp08027.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6BJg26911796980 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Jul 2019 19:42:02 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5448978064; Thu, 11 Jul 2019 19:42:02 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E17FE7805F; Thu, 11 Jul 2019 19:42:01 +0000 (GMT) Received: from sbct-3.pok.ibm.com (unknown [9.47.158.153]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 11 Jul 2019 19:42:01 +0000 (GMT) From: Stefan Berger To: libvir-list@redhat.com Date: Thu, 11 Jul 2019 15:41:43 -0400 In-Reply-To: <20190711194151.3728114-1-stefanb@linux.vnet.ibm.com> References: <20190711194151.3728114-1-stefanb@linux.vnet.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19071119-0016-0000-0000-000009CCE870 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011410; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000286; SDB=6.01230764; UDB=6.00648295; IPR=6.01012039; MB=3.00027682; MTD=3.00000008; XFM=3.00000015; UTC=2019-07-11 19:42:04 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19071119-0017-0000-0000-000043FA2435 Message-Id: <20190711194151.3728114-16-stefanb@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-07-11_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=969 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907110216 X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Thu, 11 Jul 2019 19:42:06 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Thu, 11 Jul 2019 19:42:06 +0000 (UTC) for IP:'148.163.156.1' DOMAIN:'mx0a-001b2d01.pphosted.com' HELO:'mx0a-001b2d01.pphosted.com' FROM:'stefanb@linux.vnet.ibm.com' RCPT:'' X-RedHat-Spam-Score: -0.698 (RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_NONE) 148.163.156.1 mx0a-001b2d01.pphosted.com 148.163.156.1 mx0a-001b2d01.pphosted.com X-Scanned-By: MIMEDefang 2.84 on 10.5.110.46 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-loop: libvir-list@redhat.com Cc: marcandre.lureau@redhat.com, Stefan Berger Subject: [libvirt] [PATCH v4 15/23] utils: Write a maximum of MAX_PIPE_WRITE_BYTES into a pipe X-BeenThere: libvir-list@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Development discussions about the libvirt library & tools List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: quoted-printable Sender: libvir-list-bounces@redhat.com Errors-To: libvir-list-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 11 Jul 2019 19:42:11 +0000 (UTC) Content-Type: text/plain; charset="utf-8" To avoid blocking on a write on a pipe that the receiving process does not read from, write only MAX_PIPE_WRITE_BYTES into the pipe so that we can serve other pipes as well. Signed-off-by: Stefan Berger --- src/util/vircommand.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/util/vircommand.c b/src/util/vircommand.c index 49347a9800..3ac51c77a8 100644 --- a/src/util/vircommand.c +++ b/src/util/vircommand.c @@ -86,6 +86,8 @@ struct _virCommandSendBuffer { size_t buflen; off_t offset; }; +/* max. number of bytes we write to pipe to avoid blocking on it */ +#define MAX_PIPE_WRITE_BYTES 1024 =20 struct _virCommand { int has_error; /* ENOMEM on allocation failure, -1 for anything else. = */ @@ -2251,7 +2253,7 @@ virCommandProcessIO(virCommandPtr cmd) int done; =20 done =3D write(cmd->inpipe, cmd->inbuf + inoff, - inlen - inoff); + MIN(inlen - inoff, MAX_PIPE_WRITE_BYTES)); if (done < 0) { if (errno =3D=3D EPIPE) { VIR_DEBUG("child closed stdin early, ignoring EPIP= E " --=20 2.20.1 -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list