dax: re-enable dax pmd mappings

Now that the get_user_pages() path knows how to handle dax-pmd mappings,
remove the protections that disabled dax-pmd support.

Tests available from github.com/pmem/ndctl:

    make TESTS="lib/test-dax.sh lib/test-mmap.sh" check

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dan Williams 2016-01-15 16:57:01 -08:00 committed by Linus Torvalds
parent cbb38e41a9
commit c046c321cb
2 changed files with 4 additions and 7 deletions

View File

@ -50,7 +50,8 @@ config FS_DAX_PMD
bool
default FS_DAX
depends on FS_DAX
depends on BROKEN
depends on ZONE_DEVICE
depends on TRANSPARENT_HUGEPAGE
endif # BLOCK

View File

@ -592,7 +592,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
sector_t block;
int result = 0;
/* dax pmd mappings are broken wrt gup and fork */
/* dax pmd mappings require pfn_t_devmap() */
if (!IS_ENABLED(CONFIG_FS_DAX_PMD))
return VM_FAULT_FALLBACK;
@ -717,11 +717,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
goto fallback;
}
/*
* TODO: teach vmf_insert_pfn_pmd() to support
* 'pte_special' for pmds
*/
if (pfn_t_has_page(dax.pfn)) {
if (!pfn_t_devmap(dax.pfn)) {
dax_unmap_atomic(bdev, &dax);
dax_pmd_dbg(&bh, address, "pfn not in memmap");
goto fallback;