Re: [PATCH v2] mm: Fix modifying of page protection by insert_pfn_pmd()

On Wed, Apr 24, 2019 at 10:38 AM Matthew Wilcox <willy(a)infradead.org&gt; wrote: > > On Wed, Apr 24, 2019 at 10:13:15AM -0700, Dan Williams wrote: > > I think unaligned addresses have always been passed to > > vmf_insert_pfn_pmd(), but nothing cared until this patch. I *think* > > the only change needed is the following, thoughts? > > > > diff --git a/fs/dax.c b/fs/dax.c > > index ca0671d55aa6..82aee9a87efa 100644 > > --- a/fs/dax.c > > +++ b/fs/dax.c > > @@ -1560,7 +1560,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct > > vm_fault *vmf, pfn_t *pfnp, > > } > > > > trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry); > > - result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn, > > + result = vmf_insert_pfn_pmd(vma, pmd_addr, vmf->pmd, pfn, > > write); > > We also call vmf_insert_pfn_pmd() in dax_insert_pfn_mkwrite() -- does > that need to change too? It wasn't clear to me that it was a problem. I think that one already happens to be pmd-aligned.