dax: fallback from pmd to pte on error

In preparation for consulting a badblocks list in pmem_direct_access(),
teach dax_pmd_fault() to fallback rather than fail immediately upon
encountering an error.  The thought being that reducing the span of the
dax request may avoid the error region.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
This commit is contained in:
Dan Williams 2016-02-24 14:02:06 -08:00 committed by Vishal Verma
parent a8078b1fc6
commit 8b3db9798c

View file

@ -855,8 +855,8 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
long length = dax_map_atomic(bdev, &dax);
if (length < 0) {
result = VM_FAULT_SIGBUS;
goto out;
dax_pmd_dbg(&bh, address, "dax-error fallback");
goto fallback;
}
if (length < PMD_SIZE) {
dax_pmd_dbg(&bh, address, "dax-length too small");