From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33925) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d0I25-00058E-3t for qemu-devel@nongnu.org; Mon, 17 Apr 2017 21:34:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d0I23-0003cv-R1 for qemu-devel@nongnu.org; Mon, 17 Apr 2017 21:34:17 -0400 From: Eric Blake Date: Mon, 17 Apr 2017 20:33:29 -0500 Message-Id: <20170418013356.3578-5-eblake@redhat.com> In-Reply-To: <20170418013356.3578-1-eblake@redhat.com> References: <20170418013356.3578-1-eblake@redhat.com> Subject: [Qemu-devel] [PATCH 04/31] block: Switch bdrv_make_zero() to byte-based List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, kwolf@nongnu.org, jsnow@redhat.com, Stefan Hajnoczi , Fam Zheng , Kevin Wolf , Max Reitz We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Change the internal loop iteration of zeroing a device to track by bytes instead of sectors (although we are still guaranteed that we iterate by steps that are sector-aligned). Signed-off-by: Eric Blake --- block/io.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/block/io.c b/block/io.c index 07165dc..1f8ae81 100644 --- a/block/io.c +++ b/block/io.c @@ -666,39 +666,39 @@ int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, */ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags) { - int64_t target_sectors, ret, nb_sectors, sector_num = 0; + int64_t target_size, ret, bytes, offset = 0; BlockDriverState *bs = child->bs; BlockDriverState *file; - int n; + int n; /* sectors */ - target_sectors = bdrv_nb_sectors(bs); - if (target_sectors < 0) { - return target_sectors; + target_size = bdrv_getlength(bs); + if (target_size < 0) { + return target_size; } for (;;) { - nb_sectors = MIN(target_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS); - if (nb_sectors <= 0) { + bytes = MIN(target_size - offset, BDRV_REQUEST_MAX_BYTES); + if (bytes <= 0) { return 0; } - ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n, &file); + ret = bdrv_get_block_status(bs, offset >> BDRV_SECTOR_BITS, + bytes >> BDRV_SECTOR_BITS, &n, &file); if (ret < 0) { - error_report("error getting block status at sector %" PRId64 ": %s", - sector_num, strerror(-ret)); + error_report("error getting block status at offset %" PRId64 ": %s", + offset, strerror(-ret)); return ret; } if (ret & BDRV_BLOCK_ZERO) { - sector_num += n; + offset += n * BDRV_SECTOR_BITS; continue; } - ret = bdrv_pwrite_zeroes(child, sector_num << BDRV_SECTOR_BITS, - n << BDRV_SECTOR_BITS, flags); + ret = bdrv_pwrite_zeroes(child, offset, n * BDRV_SECTOR_SIZE, flags); if (ret < 0) { - error_report("error writing zeroes at sector %" PRId64 ": %s", - sector_num, strerror(-ret)); + error_report("error writing zeroes at offset %" PRId64 ": %s", + offset, strerror(-ret)); return ret; } - sector_num += n; + offset += n * BDRV_SECTOR_SIZE; } } -- 2.9.3