@@ -301,6 +301,11 @@ static int nbd_co_flush(BlockDriverState *bs)
return nbd_client_session_co_flush(&s->client);
}
+static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+ bs->bl.max_discard = INT_MAX >> BDRV_SECTOR_BITS;
+}
+
static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
int nb_sectors)
{
@@ -396,6 +401,7 @@ static BlockDriver bdrv_nbd = {
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
+ .bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
@@ -413,6 +419,7 @@ static BlockDriver bdrv_nbd_tcp = {
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
+ .bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
@@ -430,6 +437,7 @@ static BlockDriver bdrv_nbd_unix = {
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
+ .bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
nbd_co_discard calls nbd_client_session_co_discard which uses uint32_t as the length in bytes of the data to discard due to the following definition: struct nbd_request { uint32_t magic; uint32_t type; uint64_t handle; uint64_t from; uint32_t len; <-- the length of data to be discarded, in bytes } QEMU_PACKED; Thus we should limit bl_max_discard to INT_MAX >> BDRV_SECTOR_BITS to avoid overflow. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Kevin Wolf <kwolf@redhat.com> CC: Peter Lieven <pl@kamp.de> --- block/nbd.c | 8 ++++++++ 1 file changed, 8 insertions(+)