On Mon, Apr 24, 2017 at 1:39 AM, Al Viro <v...@zeniv.linux.org.uk> wrote: > On Mon, Apr 24, 2017 at 04:11:30PM +1000, Stephen Rothwell wrote: >> Hi Dan, >> >> After merging the nvdimm tree, today's linux-next build (x86_64 >> allmodconfig) failed like this: >> >> drivers/nvdimm/x86.c: In function 'pmem_from_user': >> drivers/nvdimm/x86.c:115:11: error: implicit declaration of function >> '__copy_from_user_nocache' [-Werror=implicit-function-declaration] >> int rc = __copy_from_user_nocache(dst, src, size); >> ^ >> >> Caused by commit >> >> 6e704ff67315 ("uio, libnvdimm, pmem: implement cache bypass for all >> copy_from_iter() operations") >> >> interacting with commit >> >> 3f763453e6f2 ("kill __copy_from_user_nocache()") >> >> from the vfs tree. >> >> I have no idea why Al removed that function, > > Because the entire nocache pile is messy and misguided and the fewer of > those we have, the easier it will be to untangle the damn thing. This > particular turdlet had no users in mainline. Unfortunately, it has > grown one in nvdimm, so we'll probably have to drop that removal for now > and hope that it won't be too painful to untangle come next cycle. > > Oh, well... Guess we'll need to resurrect memcpy_nocache() threads from > December and deal witht that mess for good.
Al, I've kicked this new usage of __copy_from_user_nocache out of -next and I'll rebase my pmem vs uaccess work on vfs.git/for-next.