From nobody Mon Feb 9 17:59:19 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.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 (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1585238284; cv=none; d=zohomail.com; s=zohoarc; b=a+icEd2mcFbV/moqJ64/pJl8nmGLGTTmCcgDP3IqFd4y9jsZJX3einCVhQPWmgoS8DtVpx8AFrdWymYfO1wP83J6HhA4R4vFdjs7He/INxO50oVop13Un1IUyrRdBPmPaVWq4DlCuGcRon0hYnowc76fYDX2rn+2Llk3xNkmGHg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1585238284; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=YKoLaMzWGQQdicG7qINUiedher//2NaGm9/3rr4zILo=; b=HpccGaCVnq/hHy04BSP2UXOYUjvBhV6hnCoNabsQqpl86S5LLOoOawNGvDpY6URsnQkVl9+81t4S+vMiCSMl1r6E+0k4VXm4PTRDkqKPnPBCL9Btq8c9aWbSrwkn7NgnIZBLLBxLLxoXD8E6y7p9LA8PF/oafJxdvmokF9Qsh0U= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.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 1585238284047477.3407207674152; Thu, 26 Mar 2020 08:58:04 -0700 (PDT) Received: from localhost ([::1]:55888 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jHUtO-0002ra-Q1 for importer@patchew.org; Thu, 26 Mar 2020 11:58:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57223) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jHUs5-0000qz-WF for qemu-devel@nongnu.org; Thu, 26 Mar 2020 11:56:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jHUs4-0002eM-S0 for qemu-devel@nongnu.org; Thu, 26 Mar 2020 11:56:41 -0400 Received: from proxmox-new.maurer-it.com ([212.186.127.180]:36170) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jHUs2-0002Yu-F2; Thu, 26 Mar 2020 11:56:38 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 201EA42EB1; Thu, 26 Mar 2020 16:56:35 +0100 (CET) From: Stefan Reiter To: qemu-devel@nongnu.org, qemu-block@nongnu.org Subject: [PATCH v2 2/3] job: take each job's lock individually in job_txn_apply Date: Thu, 26 Mar 2020 16:56:27 +0100 Message-Id: <20200326155628.859862-3-s.reiter@proxmox.com> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200326155628.859862-1-s.reiter@proxmox.com> References: <20200326155628.859862-1-s.reiter@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 212.186.127.180 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: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, slp@redhat.com, mreitz@redhat.com, stefanha@redhat.com, jsnow@redhat.com, dietmar@proxmox.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" All callers of job_txn_apply hold a single job's lock, but different jobs within a transaction can have different contexts, thus we need to lock each one individually before applying the callback function. Similar to job_completed_txn_abort this also requires releasing the caller's context before and reacquiring it after to avoid recursive locks which might break AIO_WAIT_WHILE in the callback. Signed-off-by: Stefan Reiter --- job.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/job.c b/job.c index 134a07b92e..e0966162fa 100644 --- a/job.c +++ b/job.c @@ -136,17 +136,33 @@ static void job_txn_del_job(Job *job) } } =20 -static int job_txn_apply(JobTxn *txn, int fn(Job *)) +static int job_txn_apply(Job *job, int fn(Job *)) { - Job *job, *next; + AioContext *outer_ctx =3D job->aio_context; + AioContext *inner_ctx; + Job *other_job, *next; + JobTxn *txn =3D job->txn; int rc =3D 0; =20 - QLIST_FOREACH_SAFE(job, &txn->jobs, txn_list, next) { - rc =3D fn(job); + /* + * Similar to job_completed_txn_abort, we take each job's lock before + * applying fn, but since we assume that outer_ctx is held by the call= er, + * we need to release it here to avoid holding the lock twice - which = would + * break AIO_WAIT_WHILE from within fn. + */ + aio_context_release(outer_ctx); + + QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) { + inner_ctx =3D other_job->aio_context; + aio_context_acquire(inner_ctx); + rc =3D fn(other_job); + aio_context_release(inner_ctx); if (rc) { break; } } + + aio_context_acquire(outer_ctx); return rc; } =20 @@ -774,11 +790,11 @@ 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); + rc =3D job_txn_apply(job, job_prepare); if (rc) { job_completed_txn_abort(job); } else { - job_txn_apply(job->txn, job_finalize_single); + job_txn_apply(job, job_finalize_single); } } =20 @@ -824,10 +840,10 @@ static void job_completed_txn_success(Job *job) assert(other_job->ret =3D=3D 0); } =20 - job_txn_apply(txn, job_transition_to_pending); + job_txn_apply(job, job_transition_to_pending); =20 /* If no jobs need manual finalization, automatically do so */ - if (job_txn_apply(txn, job_needs_finalize) =3D=3D 0) { + if (job_txn_apply(job, job_needs_finalize) =3D=3D 0) { job_do_finalize(job); } } --=20 2.26.0