On 28.02.24 19:37, Zhao Liu wrote:
From: Zhao Liu<zhao1....@intel.com>As the comment in qapi/error, passing @errp to error_prepend() requires ERRP_GUARD(): * = Why, when and how to use ERRP_GUARD() = * * Without ERRP_GUARD(), use of the @errp parameter is restricted: ... * - It should not be passed to error_prepend(), error_vprepend() or * error_append_hint(), because that doesn't work with &error_fatal. * ERRP_GUARD() lifts these restrictions. * * To use ERRP_GUARD(), add it right at the beginning of the function. * @errp can then be used without worrying about the argument being * NULL or &error_fatal. ERRP_GUARD() could avoid the case when @errp is the pointer of error_fatal, the user can't see this additional information, because exit() happens in error_setg earlier than information is added [1]. The qcow2_co_can_store_new_dirty_bitmap() passes @errp to error_prepend(). As a BlockDriver.bdrv_co_can_store_new_dirty_bitmap method, it's called by bdrv_co_can_store_new_dirty_bitmap(). Its caller is not being called anywhere, but as the API in include/block/block-io.h, we can't ensure what kind of @errp future users will pass in. To avoid potential issues as [1] said, add missing ERRP_GUARD() at the beginning of qcow2_co_can_store_new_dirty_bitmap(). [1]: Issue description in the commit message of commit ae7c80a7bd73 ("error: New macro ERRP_GUARD()"). Cc: Eric Blake<ebl...@redhat.com> Cc: Vladimir Sementsov-Ogievskiy<vsement...@yandex-team.ru> Cc: John Snow<js...@redhat.com> Cc: Kevin Wolf<kw...@redhat.com> Cc: Hanna Reitz<hre...@redhat.com> Signed-off-by: Zhao Liu<zhao1....@intel.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru> -- Best regards, Vladimir
