From 16f0587e0a5da5b1ad76cb7c3739491bc042201c Mon Sep 17 00:00:00 2001 From: Hu Tao Date: Sun, 26 Jan 2014 11:12:37 +0800 Subject: qcow2: remove n_start and n_end of qcow2_alloc_cluster_offset() n_start can be actually calculated from offset. The number of sectors to be allocated(n_end - n_start) can be passed in in num. By removing n_start and n_end, we can save two parameters. The side effect is there is a bug in qcow2.c:preallocate() that passes incorrect n_start to qcow2_alloc_cluster_offset() is fixed. The bug can be triggerred by a larger cluster size than the default value(65536), for example: ./qemu-img create -f qcow2 \ -o 'cluster_size=131072,preallocation=metadata' file.img 4G Signed-off-by: Hu Tao Reviewed-by: Max Reitz Reviewed-by: Benoit Canet Signed-off-by: Kevin Wolf --- block/qcow2.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'block/qcow2.c') diff --git a/block/qcow2.c b/block/qcow2.c index 99a1ad13e6..a274d5f9f9 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1000,7 +1000,6 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, { BDRVQcowState *s = bs->opaque; int index_in_cluster; - int n_end; int ret; int cur_nr_sectors; /* number of sectors in current iteration */ uint64_t cluster_offset; @@ -1024,14 +1023,16 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, trace_qcow2_writev_start_part(qemu_coroutine_self()); index_in_cluster = sector_num & (s->cluster_sectors - 1); - n_end = index_in_cluster + remaining_sectors; + cur_nr_sectors = remaining_sectors; if (s->crypt_method && - n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) { - n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; + cur_nr_sectors > + QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster) { + cur_nr_sectors = + QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster; } ret = qcow2_alloc_cluster_offset(bs, sector_num << 9, - index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, &l2meta); + &cur_nr_sectors, &cluster_offset, &l2meta); if (ret < 0) { goto fail; } @@ -1408,7 +1409,7 @@ static int preallocate(BlockDriverState *bs) while (nb_sectors) { num = MIN(nb_sectors, INT_MAX >> 9); - ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, + ret = qcow2_alloc_cluster_offset(bs, offset, &num, &host_offset, &meta); if (ret < 0) { return ret; -- cgit v1.2.3