fs/dax.c: use new return type vm_fault_t
Use new return type vm_fault_t for fault handler. For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno. Once all instances are converted, vm_fault_t will become a
distinct type.
commit 1c8f422059ae ("mm: change return type to vm_fault_t")
There was an existing bug inside dax_load_hole() if vm_insert_mixed had
failed to allocate a page table, we'd return VM_FAULT_NOPAGE instead of
VM_FAULT_OOM. With new vmf_insert_mixed() this issue is addressed.
vm_insert_mixed_mkwrite has inefficiency when it returns an error value,
driver has to convert it to vm_fault_t type. With new
vmf_insert_mixed_mkwrite() this limitation will be addressed.
Link: http://lkml.kernel.org/r/20180510181121.GA15239@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0495e6f..b7012bb 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2431,8 +2431,8 @@
unsigned long pfn, pgprot_t pgprot);
int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn);
-int vm_insert_mixed_mkwrite(struct vm_area_struct *vma, unsigned long addr,
- pfn_t pfn);
+vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
+ unsigned long addr, pfn_t pfn);
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,