From patchwork Mon Nov 2 09:13:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiao Guangrong X-Patchwork-Id: 538933 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 2EE21140D7A for ; Mon, 2 Nov 2015 20:38:49 +1100 (AEDT) Received: from localhost ([::1]:41016 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtBZe-0005uY-Fh for incoming@patchwork.ozlabs.org; Mon, 02 Nov 2015 04:38:46 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57057) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtBHJ-00074J-3q for qemu-devel@nongnu.org; Mon, 02 Nov 2015 04:19:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZtBHE-0003mF-Mb for qemu-devel@nongnu.org; Mon, 02 Nov 2015 04:19:49 -0500 Received: from mga02.intel.com ([134.134.136.20]:17515) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtBHE-0003lY-71 for qemu-devel@nongnu.org; Mon, 02 Nov 2015 04:19:44 -0500 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP; 02 Nov 2015 01:19:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,234,1444719600"; d="scan'208";a="840963119" Received: from xiaoreal1.sh.intel.com (HELO xiaoreal1.sh.intel.com.sh.intel.com) ([10.239.48.79]) by fmsmga002.fm.intel.com with ESMTP; 02 Nov 2015 01:19:30 -0800 From: Xiao Guangrong To: pbonzini@redhat.com, imammedo@redhat.com Date: Mon, 2 Nov 2015 17:13:14 +0800 Message-Id: <1446455617-129562-13-git-send-email-guangrong.xiao@linux.intel.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1446455617-129562-1-git-send-email-guangrong.xiao@linux.intel.com> References: <1446455617-129562-1-git-send-email-guangrong.xiao@linux.intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.20 Cc: vsementsov@virtuozzo.com, Xiao Guangrong , ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, dan.j.williams@intel.com, rth@twiddle.net Subject: [Qemu-devel] [PATCH v7 12/35] util: let qemu_fd_getlength support block device X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org lseek can not work for all block devices as the man page says: | Some devices are incapable of seeking and POSIX does not specify | which devices must support lseek(). This patch tries to add the support on Linux by using BLKGETSIZE64 ioctl Signed-off-by: Xiao Guangrong Reviewed-by: Vladimir Sementsov-Ogievskiy --- util/osdep.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/util/osdep.c b/util/osdep.c index 5a61e19..b20c793 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -45,6 +45,11 @@ extern int madvise(caddr_t, size_t, int); #endif +#ifdef CONFIG_LINUX +#include +#include +#endif + #include "qemu-common.h" #include "qemu/sockets.h" #include "qemu/error-report.h" @@ -433,6 +438,21 @@ int64_t qemu_fd_getlength(int fd) { int64_t size; +#ifdef CONFIG_LINUX + struct stat stat_buf; + if (fstat(fd, &stat_buf) < 0) { + return -errno; + } + + if ((S_ISBLK(stat_buf.st_mode)) && !ioctl(fd, BLKGETSIZE64, &size)) { + /* The size of block device is larger than max int64_t? */ + if (size < 0) { + return -EOVERFLOW; + } + return size; + } +#endif + size = lseek(fd, 0, SEEK_END); if (size < 0) { return -errno;