Commit 8b3db979 authored Feb 24, 2016 by Dan Williams Committed by Vishal Verma May 17, 2016

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>

parent a8078b1f

fs/dax.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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");