On Tue, May 29 2018 at 1:52pm -0400, Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> wrote: > As reported by Arnd (https://lkml.org/lkml/2018/5/28/1697), dm-writecache > will fail with link errors in configs where DAX isn't present: > > drivers/md/dm-writecache.o: In function `writecache_ctr': > dm-writecache.c:(.text+0x1fdc): undefined reference to `dax_read_lock' > dm-writecache.c:(.text+0x2004): undefined reference to `dax_direct_access' > dm-writecache.c:(.text+0x21cc): undefined reference to `dax_read_unlock' > > Fix this by following the lead of the other DM modules and wrapping calls > to the generic DAX code in #if IS_ENABLED(CONFIG_DAX_DRIVER) blocks. > > We also expand the failure case for the 'p' (persistent memory) flag so > that fails on both architectures that don't support persistent memory and > on kernels that don't have DAX support configured. This prevents us from > ever hitting the BUG() in the persistent_memory_claim() stub. > > Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> > Reported-by: Arnd Bergmann <arnd@xxxxxxxx> Thanks, I've picked this up. Mike
