From nobody Tue Dec 16 13:08:54 2025 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 1494514263556109.56729510842911; Thu, 11 May 2017 07:51:03 -0700 (PDT) Received: from localhost ([::1]:48609 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d8pQg-0000i5-2k for importer@patchew.org; Thu, 11 May 2017 10:50:58 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36434) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d8pA7-0001ne-94 for qemu-devel@nongnu.org; Thu, 11 May 2017 10:33:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d8pA6-00072L-EH for qemu-devel@nongnu.org; Thu, 11 May 2017 10:33:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29016) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d8pA1-0006wm-Hq; Thu, 11 May 2017 10:33:45 -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 8892A7F4C0; Thu, 11 May 2017 14:33:44 +0000 (UTC) Received: from noname.str.redhat.com (dhcp-192-175.str.redhat.com [10.33.192.175]) by smtp.corp.redhat.com (Postfix) with ESMTP id B96A67A407; Thu, 11 May 2017 14:33:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 8892A7F4C0 Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=kwolf@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 8892A7F4C0 From: Kevin Wolf To: qemu-block@nongnu.org Date: Thu, 11 May 2017 16:32:22 +0200 Message-Id: <1494513181-7900-20-git-send-email-kwolf@redhat.com> In-Reply-To: <1494513181-7900-1-git-send-email-kwolf@redhat.com> References: <1494513181-7900-1-git-send-email-kwolf@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 [10.5.110.26]); Thu, 11 May 2017 14:33:44 +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] [PULL 19/58] 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: kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com 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" From: Fam Zheng 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 Signed-off-by: Kevin Wolf --- 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 1.8.3.1