Le Thursday 23 Jan 2014 à 11:04:07 (+0800), Hu Tao a écrit :
> In case of do preallocating metadata with a large cluster size,
In the case of a metadata preallocation with
> qcow2_alloc_cluster_offset() can allocate nothing and returns
> a NULL l2meta. This patch checks for it and link2 l2 with only
> valid l2meta.
>
> Replace 9 and 512 with BDRV_SECTOR_BITS, BDRV_SECTOR_SIZE
> respectively while at the function.
>
> Reviewed-by: Max Reitz <mre...@redhat.com>
> Signed-off-by: Hu Tao <hu...@cn.fujitsu.com>
> ---
> block/qcow2.c | 25 ++++++++++++++-----------
> 1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 0a310cc..f989247 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -1390,22 +1390,24 @@ static int preallocate(BlockDriverState *bs)
> int ret;
> QCowL2Meta *meta;
>
> - nb_sectors = bdrv_getlength(bs) >> 9;
> + nb_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
> offset = 0;
>
> while (nb_sectors) {
> - num = MIN(nb_sectors, INT_MAX >> 9);
> + num = MIN(nb_sectors, INT_MAX >> BDRV_SECTOR_BITS);
> ret = qcow2_alloc_cluster_offset(bs, offset, &num,
> &host_offset, &meta);
> if (ret < 0) {
> return ret;
> }
>
> - ret = qcow2_alloc_cluster_link_l2(bs, meta);
> - if (ret < 0) {
> - qcow2_free_any_clusters(bs, meta->alloc_offset,
> meta->nb_clusters,
> - QCOW2_DISCARD_NEVER);
> - return ret;
> + if (meta) {
> + ret = qcow2_alloc_cluster_link_l2(bs, meta);
> + if (ret < 0) {
> + qcow2_free_any_clusters(bs, meta->alloc_offset,
> + meta->nb_clusters,
> QCOW2_DISCARD_NEVER);
> + return ret;
> + }
> }
Maybe if (meta) could include the following line to remove another extra test.
QLIST_REMOVE(meta, next_in_flight);
>
> /* There are no dependent requests, but we need to remove our request
> @@ -1417,7 +1419,7 @@ static int preallocate(BlockDriverState *bs)
> /* TODO Preallocate data if requested */
>
> nb_sectors -= num;
> - offset += num << 9;
> + offset += num << BDRV_SECTOR_BITS;
> }
>
> /*
> @@ -1426,9 +1428,10 @@ static int preallocate(BlockDriverState *bs)
> * EOF). Extend the image to the last allocated sector.
> */
> if (host_offset != 0) {
> - uint8_t buf[512];
> - memset(buf, 0, 512);
> - ret = bdrv_write(bs->file, (host_offset >> 9) + num - 1, buf, 1);
> + uint8_t buf[BDRV_SECTOR_SIZE];
> + memset(buf, 0, BDRV_SECTOR_SIZE);
> + ret = bdrv_write(bs->file, (host_offset >> BDRV_SECTOR_BITS) + num -
> 1,
> + buf, 1);
> if (ret < 0) {
> return ret;
> }
> --
> 1.8.5.2.229.g4448466
>
>
