Am 02.02.2015 um 21:09 schrieb Denis V. Lunev:
> qemu_gluster_co_discard calculates size to discard as follows
> size_t size = nb_sectors * BDRV_SECTOR_SIZE;
> ret = glfs_discard_async(s->fd, offset, size, &gluster_finish_aiocb, acb);
>
> glfs_discard_async is declared as follows:
> int glfs_discard_async (glfs_fd_t *fd, off_t length, size_t lent,
> glfs_io_cbk fn, void *data) __THROW
> This is problematic on i686 as sizeof(size_t) == 4.
>
> Set bl_max_discard to SIZE_MAX >> BDRV_SECTOR_BITS to avoid overflow
> on i386.
>
> Signed-off-by: Denis V. Lunev <d...@openvz.org>
> CC: Kevin Wolf <kw...@redhat.com>
> CC: Peter Lieven <p...@kamp.de>
> ---
> block/gluster.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/block/gluster.c b/block/gluster.c
> index 1eb3a8c..8a8c153 100644
> --- a/block/gluster.c
> +++ b/block/gluster.c
> @@ -622,6 +622,11 @@ out:
> return ret;
> }
>
> +static void qemu_gluster_refresh_limits(BlockDriverState *bs, Error **errp)
> +{
> + bs->bl.max_discard = MIN(SIZE_MAX >> BDRV_SECTOR_BITS, INT_MAX);
> +}
> +
Looking at the gluster code bl.max_transfer_length should have the same limit,
but thats a different patch.
> #ifdef CONFIG_GLUSTERFS_DISCARD
> static coroutine_fn int qemu_gluster_co_discard(BlockDriverState *bs,
> int64_t sector_num, int nb_sectors)
> @@ -735,6 +740,7 @@ static BlockDriver bdrv_gluster = {
> #ifdef CONFIG_GLUSTERFS_DISCARD
> .bdrv_co_discard = qemu_gluster_co_discard,
> #endif
> + .bdrv_refresh_limits = qemu_gluster_refresh_limits,
> #ifdef CONFIG_GLUSTERFS_ZEROFILL
> .bdrv_co_write_zeroes = qemu_gluster_co_write_zeroes,
> #endif
> @@ -762,6 +768,7 @@ static BlockDriver bdrv_gluster_tcp = {
> #ifdef CONFIG_GLUSTERFS_DISCARD
> .bdrv_co_discard = qemu_gluster_co_discard,
> #endif
> + .bdrv_refresh_limits = qemu_gluster_refresh_limits,
> #ifdef CONFIG_GLUSTERFS_ZEROFILL
> .bdrv_co_write_zeroes = qemu_gluster_co_write_zeroes,
> #endif
> @@ -789,6 +796,7 @@ static BlockDriver bdrv_gluster_unix = {
> #ifdef CONFIG_GLUSTERFS_DISCARD
> .bdrv_co_discard = qemu_gluster_co_discard,
> #endif
> + .bdrv_refresh_limits = qemu_gluster_refresh_limits,
> #ifdef CONFIG_GLUSTERFS_ZEROFILL
> .bdrv_co_write_zeroes = qemu_gluster_co_write_zeroes,
> #endif
> @@ -816,6 +824,7 @@ static BlockDriver bdrv_gluster_rdma = {
> #ifdef CONFIG_GLUSTERFS_DISCARD
> .bdrv_co_discard = qemu_gluster_co_discard,
> #endif
> + .bdrv_refresh_limits = qemu_gluster_refresh_limits,
> #ifdef CONFIG_GLUSTERFS_ZEROFILL
> .bdrv_co_write_zeroes = qemu_gluster_co_write_zeroes,
> #endif
Reviewed-by: Peter Lieven <p...@kamp.de>
