From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44518) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YJlxq-00043a-EA for qemu-devel@nongnu.org; Fri, 06 Feb 2015 11:41:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YJlxm-0000cx-7K for qemu-devel@nongnu.org; Fri, 06 Feb 2015 11:41:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39273) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YJlxl-0000cr-Rd for qemu-devel@nongnu.org; Fri, 06 Feb 2015 11:41:02 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t16Gf1M6012462 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Fri, 6 Feb 2015 11:41:01 -0500 From: Kevin Wolf Date: Fri, 6 Feb 2015 17:40:13 +0100 Message-Id: <1423240849-15499-7-git-send-email-kwolf@redhat.com> In-Reply-To: <1423240849-15499-1-git-send-email-kwolf@redhat.com> References: <1423240849-15499-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 06/42] block: use fallocate(FALLOC_FL_ZERO_RANGE) in handle_aiocb_write_zeroes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com From: "Denis V. Lunev" 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. CC: Kevin Wolf CC: Stefan Hajnoczi CC: Peter Lieven CC: Fam Zheng Signed-off-by: Denis V. Lunev Reviewed-by: Max Reitz Signed-off-by: Kevin Wolf --- block/raw-posix.c | 15 +++++++++++++-- configure | 19 +++++++++++++++++++ 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/block/raw-posix.c b/block/raw-posix.c index d3910fd..5a777e7 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__) @@ -902,7 +902,7 @@ static int translate_err(int err) return err; } -#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) +#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) || defined(CONFIG_FALLOCATE_ZERO_RANGE) static int do_fallocate(int fd, int mode, off_t offset, off_t len) { do { @@ -954,6 +954,17 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb) } #endif +#ifdef CONFIG_FALLOCATE_ZERO_RANGE + if (s->has_write_zeroes) { + int ret = do_fallocate(s->fd, FALLOC_FL_ZERO_RANGE, + aiocb->aio_offset, aiocb->aio_nbytes); + if (ret == 0 || ret != -ENOTSUP) { + return ret; + } + s->has_write_zeroes = false; + } +#endif + return -ENOTSUP; } diff --git a/configure b/configure index f185dd0..e00e03a 100755 --- a/configure +++ b/configure @@ -3335,6 +3335,22 @@ 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 > $TMPC << EOF @@ -4567,6 +4583,9 @@ fi if test "$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 -- 1.8.3.1