From patchwork Fri Jun 3 08:48:59 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 629729 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rLdY44r54z9t8J for ; Fri, 3 Jun 2016 19:08:08 +1000 (AEST) Received: from localhost ([::1]:53509 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8l5K-0007el-Kq for incoming@patchwork.ozlabs.org; Fri, 03 Jun 2016 05:08:06 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54965) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8knj-0006q5-RF for qemu-devel@nongnu.org; Fri, 03 Jun 2016 04:49:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b8kni-0001rz-SB for qemu-devel@nongnu.org; Fri, 03 Jun 2016 04:49:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43996) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8kna-0001qN-Ev; Fri, 03 Jun 2016 04:49:46 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E8CF862668; Fri, 3 Jun 2016 08:49:45 +0000 (UTC) Received: from ad.usersys.redhat.com (dhcp-15-133.nay.redhat.com [10.66.15.133]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u538nKXp023508; Fri, 3 Jun 2016 04:49:42 -0400 From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 3 Jun 2016 16:48:59 +0800 Message-Id: <1464943756-14143-6-git-send-email-famz@redhat.com> In-Reply-To: <1464943756-14143-1-git-send-email-famz@redhat.com> References: <1464943756-14143-1-git-send-email-famz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 03 Jun 2016 08:49:45 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v6 05/22] 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, rjones@redhat.com, John Snow , Jeff Cody , Markus Armbruster , Max Reitz , stefanha@redhat.com, den@openvz.org, pbonzini@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" They are wrappers of POSIX fcntl "file private locking". Signed-off-by: Fam Zheng --- include/qemu/osdep.h | 2 ++ util/osdep.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 6937694..749214a 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -280,6 +280,8 @@ int qemu_madvise(void *addr, size_t len, int advice); int qemu_open(const char *name, int flags, ...); int qemu_close(int fd); +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); #if defined(__HAIKU__) && defined(__i386__) #define FMT_pid "%ld" diff --git a/util/osdep.c b/util/osdep.c index 9a7a439..085ed52 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -137,6 +137,35 @@ 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 = { + .l_whence = SEEK_SET, + .l_start = start, + .l_len = len, + .l_type = fl_type, + }; + do { + ret = fcntl(fd, F_OFD_SETLK, &fl); + } while (ret == -1 && errno == EINTR); + return ret == -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); +} #endif /*