Stephen reported: With just Linus' tree, today's linux-next build (powerpc ppc64_defconfig) produced this warning: fs/dax.c: In function 'dax_iomap_fault': fs/dax.c:1462:35: warning: passing argument 2 of 'dax_iomap_pmd_fault' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] return dax_iomap_pmd_fault(vmf, ops); ^ fs/dax.c:1439:12: note: expected 'struct iomap_ops *' but argument is of type 'const struct iomap_ops *' static int dax_iomap_pmd_fault(struct vm_fault *vmf, struct iomap_ops *ops) ^ Introduced by commit a2d581675d48 ("mm,fs,dax: change ->pmd_fault to ->huge_fault") which missed fixing up the !CONFIG_FS_DAX_PMD case. Reported-by: Stephen Rothwell <sfr(a)canb.auug.org.au&gt; Signed-off-by: Dave Jiang <dave.jiang(a)intel.com&gt; --- fs/dax.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/dax.c b/fs/dax.c index 5ae8b71..7436c98 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1436,7 +1436,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, return result; } #else -static int dax_iomap_pmd_fault(struct vm_fault *vmf, struct iomap_ops *ops) +static int dax_iomap_pmd_fault(struct vm_fault *vmf, + const struct iomap_ops *ops) { return VM_FAULT_FALLBACK; }