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FAILED: patch "[PATCH] filesystem-dax: Fix use of zero page" failed to apply to 4.14-stable tree

PATCH [email protected] 1 participant 1 message Sep 30, 2018

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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 <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From b90ca5cc32f59bb214847c6855959702f00c6801 Mon Sep 17 00:00:00 2001

From: Matthew Wilcox <[email protected]>
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 <[email protected]>
Fixes 91d25ba8a6b0 ("dax: use common 4k zero page for dax mmap reads")
Signed-off-by Matthew Wilcox <[email protected]>
Reviewed-by Ross Zwisler <[email protected]>
Signed-off-by Dan Williams <[email protected]>
fs/dax.c +2 -11
index f32d7125ad0f..b68ce484e1be 100644
@@ -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;
 }