From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58870) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YLa4K-0005zz-JE for qemu-devel@nongnu.org; Wed, 11 Feb 2015 11:23:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YLa4F-0002r5-Iw for qemu-devel@nongnu.org; Wed, 11 Feb 2015 11:23:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46871) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YLa4F-0002qz-Af for qemu-devel@nongnu.org; Wed, 11 Feb 2015 11:23:11 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t1BGNAjG025254 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Wed, 11 Feb 2015 11:23:10 -0500 From: Kevin Wolf Date: Wed, 11 Feb 2015 17:23:08 +0100 Message-Id: <1423671788-31716-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH] vpc: Implement bdrv_co_get_status() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com This implements bdrv_co_get_status() for VHD images. This can significantly speed up qemu-img convert operation because only with this function implemented sparseness can be considered. (Before, converting a 1 TB empty image took several minutes for me, now it's instantaneous.) Signed-off-by: Kevin Wolf --- block/vpc.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 52 insertions(+), 2 deletions(-) diff --git a/block/vpc.c b/block/vpc.c index 46803b1..379ff4a 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -597,6 +597,55 @@ static coroutine_fn int vpc_co_write(BlockDriverState *bs, int64_t sector_num, return ret; } +static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, int *pnum) +{ + BDRVVPCState *s = bs->opaque; + VHDFooter *footer = (VHDFooter *) s->footer_buf; + int64_t start, offset; + bool allocated; + int n; + + if (be32_to_cpu(footer->type) == VHD_FIXED) { + *pnum = nb_sectors; + return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA | + (sector_num << BDRV_SECTOR_BITS); + } + + offset = get_sector_offset(bs, sector_num, 0); + + *pnum = 1; + start = offset; + allocated = (offset != -1); + nb_sectors--; + + while (nb_sectors > 0) { + offset = get_sector_offset(bs, sector_num, 0); + + if ((offset != -1) != allocated) { + break; + } + + if (allocated && offset != start + (*pnum * 512)) { + break; + } + + /* All sectors in a block are contiguous (without using the bitmap) */ + n = ROUND_UP(sector_num + 1, s->block_size / 512) - sector_num; + n = MIN(n, nb_sectors); + + *pnum += n; + sector_num += n; + nb_sectors -= n; + } + + if (allocated) { + return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start; + } else { + return 0; + } +} + /* * Calculates the number of cylinders, heads and sectors per cylinder * based on a given number of sectors. This is the algorithm described @@ -907,8 +956,9 @@ static BlockDriver bdrv_vpc = { .bdrv_reopen_prepare = vpc_reopen_prepare, .bdrv_create = vpc_create, - .bdrv_read = vpc_co_read, - .bdrv_write = vpc_co_write, + .bdrv_read = vpc_co_read, + .bdrv_write = vpc_co_write, + .bdrv_co_get_block_status = vpc_co_get_block_status, .bdrv_get_info = vpc_get_info, -- 1.8.3.1