From: Joao Martins <joao.m.martins@xxxxxxxxxx> Subject: device-dax: factor out page mapping initialization Move initialization of page->mapping into a separate helper. This is in preparation to move the mapping set to be prior to inserting the page table entry and also for tidying up compound page handling into one helper. Link: https://lkml.kernel.org/r/20211202204422.26777-9-joao.m.martins@xxxxxxxxxx Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Dave Jiang <dave.jiang@xxxxxxxxx> Cc: Jane Chu <jane.chu@xxxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx> Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/dax/device.c | 45 ++++++++++++++++++++--------------------- 1 file changed, 23 insertions(+), 22 deletions(-) --- a/drivers/dax/device.c~device-dax-factor-out-page-mapping-initialization +++ a/drivers/dax/device.c @@ -73,6 +73,27 @@ __weak phys_addr_t dax_pgoff_to_phys(str return -1; } +static void dax_set_mapping(struct vm_fault *vmf, pfn_t pfn, + unsigned long fault_size) +{ + unsigned long i, nr_pages = fault_size / PAGE_SIZE; + struct file *filp = vmf->vma->vm_file; + pgoff_t pgoff; + + pgoff = linear_page_index(vmf->vma, + ALIGN(vmf->address, fault_size)); + + for (i = 0; i < nr_pages; i++) { + struct page *page = pfn_to_page(pfn_t_to_pfn(pfn) + i); + + if (page->mapping) + continue; + + page->mapping = filp->f_mapping; + page->index = pgoff + i; + } +} + static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf, pfn_t *pfn) { @@ -224,28 +245,8 @@ static vm_fault_t dev_dax_huge_fault(str rc = VM_FAULT_SIGBUS; } - if (rc == VM_FAULT_NOPAGE) { - unsigned long i; - pgoff_t pgoff; - - /* - * In the device-dax case the only possibility for a - * VM_FAULT_NOPAGE result is when device-dax capacity is - * mapped. No need to consider the zero page, or racing - * conflicting mappings. - */ - pgoff = linear_page_index(vmf->vma, - ALIGN(vmf->address, fault_size)); - for (i = 0; i < fault_size / PAGE_SIZE; i++) { - struct page *page; - - page = pfn_to_page(pfn_t_to_pfn(pfn) + i); - if (page->mapping) - continue; - page->mapping = filp->f_mapping; - page->index = pgoff + i; - } - } + if (rc == VM_FAULT_NOPAGE) + dax_set_mapping(vmf, pfn, fault_size); dax_read_unlock(id); return rc; _
