From nobody Tue Feb 10 04:16:37 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1493178335907929.5208957506425; Tue, 25 Apr 2017 20:45:35 -0700 (PDT) Received: from localhost ([::1]:52465 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d3DtV-0003NG-OV for importer@patchew.org; Tue, 25 Apr 2017 23:45:33 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43728) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d3Djc-0003CF-WA for qemu-devel@nongnu.org; Tue, 25 Apr 2017 23:35:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d3Djc-0001s6-4A for qemu-devel@nongnu.org; Tue, 25 Apr 2017 23:35:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34394) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d3DjY-0001r1-RW; Tue, 25 Apr 2017 23:35:16 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C658F65CFE; Wed, 26 Apr 2017 03:35:15 +0000 (UTC) Received: from lemon.redhat.com (ovpn-8-31.pek2.redhat.com [10.72.8.31]) by smtp.corp.redhat.com (Postfix) with ESMTP id CD8B41759E; Wed, 26 Apr 2017 03:35:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C658F65CFE Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=famz@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com C658F65CFE From: Fam Zheng To: qemu-devel@nongnu.org Date: Wed, 26 Apr 2017 11:34:11 +0800 Message-Id: <20170426033413.17192-20-famz@redhat.com> In-Reply-To: <20170426033413.17192-1-famz@redhat.com> References: <20170426033413.17192-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 26 Apr 2017 03:35:15 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v15 19/21] osdep: Add qemu_lock_fd and qemu_unlock_fd 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 , qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" They are wrappers of POSIX fcntl "file private locking", with a convenient "try lock" wrapper implemented with F_OFD_GETLK. Signed-off-by: Fam Zheng Reviewed-by: Max Reitz --- include/qemu/osdep.h | 3 +++ util/osdep.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 122ff06..1c9f5e2 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -341,6 +341,9 @@ int qemu_close(int fd); #ifndef _WIN32 int qemu_dup(int fd); #endif +int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive); +int qemu_unlock_fd(int fd, int64_t start, int64_t len); +int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive); =20 #if defined(__HAIKU__) && defined(__i386__) #define FMT_pid "%ld" diff --git a/util/osdep.c b/util/osdep.c index 06fb1cf..3de4a18 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -140,6 +140,54 @@ static int qemu_parse_fdset(const char *param) { return qemu_parse_fd(param); } + +static int qemu_lock_fcntl(int fd, int64_t start, int64_t len, int fl_type) +{ +#ifdef F_OFD_SETLK + int ret; + struct flock fl =3D { + .l_whence =3D SEEK_SET, + .l_start =3D start, + .l_len =3D len, + .l_type =3D fl_type, + }; + ret =3D fcntl(fd, F_OFD_SETLK, &fl); + return ret =3D=3D -1 ? -errno : 0; +#else + return -ENOTSUP; +#endif +} + +int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive) +{ + return qemu_lock_fcntl(fd, start, len, exclusive ? F_WRLCK : F_RDLCK); +} + +int qemu_unlock_fd(int fd, int64_t start, int64_t len) +{ + return qemu_lock_fcntl(fd, start, len, F_UNLCK); +} + +int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive) +{ +#ifdef F_OFD_SETLK + int ret; + struct flock fl =3D { + .l_whence =3D SEEK_SET, + .l_start =3D start, + .l_len =3D len, + .l_type =3D exclusive ? F_WRLCK : F_RDLCK, + }; + ret =3D fcntl(fd, F_OFD_GETLK, &fl); + if (ret =3D=3D -1) { + return -errno; + } else { + return fl.l_type =3D=3D F_UNLCK ? 0 : -EAGAIN; + } +#else + return -ENOTSUP; +#endif +} #endif =20 /* --=20 2.9.3