From patchwork Fri Dec 26 12:35:08 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Denis V. Lunev" X-Patchwork-Id: 424115 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 8984F140081 for ; Fri, 26 Dec 2014 23:38:45 +1100 (AEDT) Received: from localhost ([::1]:53189 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y4UAF-00076s-I6 for incoming@patchwork.ozlabs.org; Fri, 26 Dec 2014 07:38:43 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43887) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y4U6t-0001Hl-9E for qemu-devel@nongnu.org; Fri, 26 Dec 2014 07:35:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y4U6r-0001rV-CW for qemu-devel@nongnu.org; Fri, 26 Dec 2014 07:35:15 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:45714 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y4U6p-0001p3-6a for qemu-devel@nongnu.org; Fri, 26 Dec 2014 07:35:13 -0500 Received: from hades.sw.ru ([10.30.8.132]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id sBQCZ0YY026257; Fri, 26 Dec 2014 15:35:05 +0300 (MSK) From: "Denis V. Lunev" To: Date: Fri, 26 Dec 2014 15:35:08 +0300 Message-Id: <1419597313-20514-3-git-send-email-den@openvz.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1419597313-20514-1-git-send-email-den@openvz.org> References: <1419597313-20514-1-git-send-email-den@openvz.org> X-detected-operating-system: by eggs.gnu.org: OpenBSD 3.x X-Received-From: 195.214.232.25 Cc: Kevin Wolf , "Denis V. Lunev" , qemu-devel@nongnu.org, Stefan Hajnoczi Subject: [Qemu-devel] [PATCH 2/7] block: use fallocate(FALLOC_FL_ZERO_RANGE) in handle_aiocb_write_zeroes 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 This efficiently writes zeroes on Linux if the kernel is capable enough. FALLOC_FL_ZERO_RANGE correctly handles all cases, including and not including file expansion. Signed-off-by: Denis V. Lunev CC: Kevin Wolf CC: Stefan Hajnoczi --- block/raw-posix.c | 13 ++++++++++++- configure | 19 +++++++++++++++++++ 2 files changed, 31 insertions(+), 1 deletion(-) diff --git a/block/raw-posix.c b/block/raw-posix.c index e51293a..66ebaab 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -60,7 +60,7 @@ #define FS_NOCOW_FL 0x00800000 /* Do not cow file */ #endif #endif -#ifdef CONFIG_FALLOCATE_PUNCH_HOLE +#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) || defined(CONFIG_FALLOCATE_ZERO_RANGE) #include #endif #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) @@ -919,6 +919,17 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb) return xfs_write_zeroes(s, aiocb->aio_offset, aiocb->aio_nbytes); } #endif + +#ifdef CONFIG_FALLOCATE_ZERO_RANGE + do { + if (fallocate(s->fd, FALLOC_FL_ZERO_RANGE, + aiocb->aio_offset, aiocb->aio_nbytes) == 0) { + return 0; + } + } while (errno == EINTR); + + ret = -errno; +#endif } if (ret == -ENODEV || ret == -ENOSYS || ret == -EOPNOTSUPP || diff --git a/configure b/configure index cae588c..dfcf7b3 100755 --- a/configure +++ b/configure @@ -3309,6 +3309,22 @@ if compile_prog "" "" ; then fallocate_punch_hole=yes fi +# check that fallocate supports range zeroing inside the file +fallocate_zero_range=no +cat > $TMPC << EOF +#include +#include + +int main(void) +{ + fallocate(0, FALLOC_FL_ZERO_RANGE, 0, 0); + return 0; +} +EOF +if compile_prog "" "" ; then + fallocate_zero_range=yes +fi + # check for posix_fallocate posix_fallocate=no cat > $TMPC << EOF @@ -4538,6 +4554,9 @@ fi if test "$fallocate_punch_hole" = "yes" ; then echo "CONFIG_FALLOCATE_PUNCH_HOLE=y" >> $config_host_mak fi +if test "$fallocate_zero_range" = "yes" ; then + echo "CONFIG_FALLOCATE_ZERO_RANGE=y" >> $config_host_mak +fi if test "$posix_fallocate" = "yes" ; then echo "CONFIG_POSIX_FALLOCATE=y" >> $config_host_mak fi