On Thu, May 26, 2022 at 10:35:59AM -0600, Logan Gunthorpe wrote: > Move struct r5l_log definition to raid5-log.h. While this reduces > encapsulation, it is necessary for the definition of r5l_log to be > public so that rcu_access_pointer() can be used on conf-log in the > next patch. > > rcu_access_pointer(p) doesn't technically dereference the log pointer > however, it does use typeof(*p) and some older GCC versions (anything > earlier than gcc-10) will wrongly try to dereference the structure: > > include/linux/rcupdate.h:384:9: error: dereferencing pointer to > incomplete type ‘struct r5l_log’ > > typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \ > ^ > > include/linux/rcupdate.h:495:31: note: in expansion of > macro ‘__rcu_access_pointer’ > > #define rcu_access_pointer(p) __rcu_access_pointer((p), > __UNIQUE_ID(rcu), __rcu) > > To prevent this, simply provide the definition where > rcu_access_pointer() may be used. What about just moving any code that does the rcu_access_pointer on conf->log to raid5-cache.c and doing an out of line call for it instead?
