The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b90ca5cc32f59bb214847c6855959702f00c6801 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Date: Tue, 11 Sep 2018 21:27:44 -0700
Subject: [PATCH] filesystem-dax: Fix use of zero page
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@xxxxxxxxxxxxxxx>
Fixes: 91d25ba8a6b0 ("dax: use common 4k zero page for dax mmap reads")
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
diff --git a/fs/dax.c b/fs/dax.c
index f32d7125ad0f..b68ce484e1be 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1120,21 +1120,12 @@ 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;
}
