The new dm-writecache driver inconditionally uses the dax subsystem, leading to link errors in some configurations: 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' It seems wrong to require DAX in order to build the writecache driver, but that at least avoids randconfig build errors. Fixes: bb15b431d650 ("dm: add writecache target") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/md/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 852c7ebe2902..f8ecf2da1edf 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -338,6 +338,7 @@ config DM_CACHE_SMQ config DM_WRITECACHE tristate "Writecache target" depends on BLK_DEV_DM + depends on DAX ---help--- The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely -- 2.9.0