From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40597) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YRPVY-0004Tm-7W for qemu-devel@nongnu.org; Fri, 27 Feb 2015 13:19:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YRPVS-0001AS-3I for qemu-devel@nongnu.org; Fri, 27 Feb 2015 13:19:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42915) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YRPVR-0001AG-NS for qemu-devel@nongnu.org; Fri, 27 Feb 2015 13:19:22 -0500 From: Stefan Hajnoczi Date: Fri, 27 Feb 2015 18:18:03 +0000 Message-Id: <1425061147-1411-6-git-send-email-stefanha@redhat.com> In-Reply-To: <1425061147-1411-1-git-send-email-stefanha@redhat.com> References: <1425061147-1411-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PULL 05/69] vpc: Implement bdrv_co_get_block_status() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Peter Maydell From: Kevin Wolf This implements bdrv_co_get_block_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 Reviewed-by: Max Reitz --- block/vpc.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 2 deletions(-) diff --git a/block/vpc.c b/block/vpc.c index 7fddbf0..1533b6a 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -597,6 +597,51 @@ 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, next; + 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); + start = offset; + allocated = (offset != -1); + *pnum = 0; + + do { + /* All sectors in a block are contiguous (without using the bitmap) */ + n = ROUND_UP(sector_num + 1, s->block_size / BDRV_SECTOR_SIZE) + - sector_num; + n = MIN(n, nb_sectors); + + *pnum += n; + sector_num += n; + nb_sectors -= n; + next = start + (*pnum * BDRV_SECTOR_SIZE); + + if (nb_sectors == 0) { + break; + } + + offset = get_sector_offset(bs, sector_num, 0); + } while ((allocated && offset == next) || (!allocated && offset == -1)); + + 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 @@ -903,8 +948,9 @@ 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, -- 2.1.0