filesystem-dax: Fix use of zero page

commit b90ca5cc32f59bb214847c6855959702f00c6801 upstream.

Use my_zero_pfn instead of ZERO_PAGE(), and pass the vaddr to it instead
of zero so it works on MIPS and s390 who reference the vaddr to select a
zero page.

Cc: <stable@vger.kernel.org>
Fixes: 91d25ba8a6b0 ("dax: use common 4k zero page for dax mmap reads")
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/dax.c b/fs/dax.c
index 641192808bb69054a634b6f5b229c2ca25f308bf..94f9fe002b126616e8f0724bfd1f54294f93629c 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1007,21 +1007,12 @@ static vm_fault_t dax_load_hole(struct address_space *mapping, void *entry,
 {
        struct inode *inode = mapping->host;
        unsigned long vaddr = vmf->address;
-       vm_fault_t ret = VM_FAULT_NOPAGE;
-       struct page *zero_page;
-       pfn_t pfn;
-
-       zero_page = ZERO_PAGE(0);
-       if (unlikely(!zero_page)) {
-               ret = VM_FAULT_OOM;
-               goto out;
-       }
+       pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr));
+       vm_fault_t ret;
 
-       pfn = page_to_pfn_t(zero_page);
        dax_insert_mapping_entry(mapping, vmf, entry, pfn, RADIX_DAX_ZERO_PAGE,
                        false);
        ret = vmf_insert_mixed(vmf->vma, vaddr, pfn);
-out:
        trace_dax_load_hole(inode, vmf, ret);
        return ret;
 }