From nobody Fri Dec 19 20:13:39 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1554153657544192.9605509393739; Mon, 1 Apr 2019 14:20:57 -0700 (PDT) Received: from localhost ([127.0.0.1]:42411 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hB4MQ-0002YF-7W for importer@patchew.org; Mon, 01 Apr 2019 17:20:54 -0400 Received: from eggs.gnu.org ([209.51.188.92]:40805) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hB44X-0001Jx-2j for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hB44V-0003NJ-5P for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:24 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:50602 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hB44U-0003Ha-Rq for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:23 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x31L1raU095864 for ; Mon, 1 Apr 2019 17:02:13 -0400 Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rkswegwck-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 01 Apr 2019 17:02:13 -0400 Received: from localhost by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 1 Apr 2019 22:02:09 +0100 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x31L28kN22151382 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 1 Apr 2019 21:02:08 GMT Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 096F1BE054; Mon, 1 Apr 2019 21:02:08 +0000 (GMT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C8D97BE059; Mon, 1 Apr 2019 21:02:07 +0000 (GMT) Received: from localhost (unknown [9.80.94.43]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Mon, 1 Apr 2019 21:02:07 +0000 (GMT) From: Michael Roth To: qemu-devel@nongnu.org Date: Mon, 1 Apr 2019 15:59:10 -0500 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190401210011.16009-1-mdroth@linux.vnet.ibm.com> References: <20190401210011.16009-1-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19040121-0004-0000-0000-000014F71F14 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010857; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000283; SDB=6.01182941; UDB=6.00619269; IPR=6.00963684; MB=3.00026249; MTD=3.00000008; XFM=3.00000015; UTC=2019-04-01 21:02:10 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19040121-0005-0000-0000-00008B1BBECF Message-Id: <20190401210011.16009-37-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-04-01_06:, , 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904010136 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.158.5 Subject: [Qemu-devel] [PATCH 36/97] job: Fix nested aio_poll() hanging in job_txn_apply X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Fam Zheng All callers have acquired ctx already. Doing that again results in aio_poll() hang. This fixes the problem that a BDRV_POLL_WHILE() in the callback cannot make progress because ctx is recursively locked, for example, when drive-backup finishes. There are two callers of job_finalize(): fam@lemon:~/work/qemu [master]$ git grep -w -A1 '^\s*job_finalize' blockdev.c: job_finalize(&job->job, errp); blockdev.c- aio_context_release(aio_context); -- job-qmp.c: job_finalize(job, errp); job-qmp.c- aio_context_release(aio_context); -- tests/test-blockjob.c: job_finalize(&job->job, &error_abort); tests/test-blockjob.c- assert(job->job.status =3D=3D JOB_STATUS_CONC= LUDED); Ignoring the test, it's easy to see both callers to job_finalize (and job_do_finalize) have acquired the context. Cc: qemu-stable@nongnu.org Reported-by: Gu Nini Reviewed-by: Eric Blake Signed-off-by: Fam Zheng Signed-off-by: Kevin Wolf (cherry picked from commit 49880165a44f26dc84651858750facdee31f2513) Signed-off-by: Michael Roth --- job.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) diff --git a/job.c b/job.c index e36ebaafd8..a3bec7fb22 100644 --- a/job.c +++ b/job.c @@ -136,21 +136,13 @@ static void job_txn_del_job(Job *job) } } =20 -static int job_txn_apply(JobTxn *txn, int fn(Job *), bool lock) +static int job_txn_apply(JobTxn *txn, int fn(Job *)) { - AioContext *ctx; Job *job, *next; int rc =3D 0; =20 QLIST_FOREACH_SAFE(job, &txn->jobs, txn_list, next) { - if (lock) { - ctx =3D job->aio_context; - aio_context_acquire(ctx); - } rc =3D fn(job); - if (lock) { - aio_context_release(ctx); - } if (rc) { break; } @@ -807,11 +799,11 @@ static void job_do_finalize(Job *job) assert(job && job->txn); =20 /* prepare the transaction to complete */ - rc =3D job_txn_apply(job->txn, job_prepare, true); + rc =3D job_txn_apply(job->txn, job_prepare); if (rc) { job_completed_txn_abort(job); } else { - job_txn_apply(job->txn, job_finalize_single, true); + job_txn_apply(job->txn, job_finalize_single); } } =20 @@ -857,10 +849,10 @@ static void job_completed_txn_success(Job *job) assert(other_job->ret =3D=3D 0); } =20 - job_txn_apply(txn, job_transition_to_pending, false); + job_txn_apply(txn, job_transition_to_pending); =20 /* If no jobs need manual finalization, automatically do so */ - if (job_txn_apply(txn, job_needs_finalize, false) =3D=3D 0) { + if (job_txn_apply(txn, job_needs_finalize) =3D=3D 0) { job_do_finalize(job); } } --=20 2.17.1