Commit 9c5a05bc authored Feb 05, 2016 by Ross Zwisler Committed by Linus Torvalds Feb 05, 2016

block: fix pfn_mkwrite() DAX fault handler



Previously the pfn_mkwrite() fault handler for raw block devices called
bldev_dax_fault() -> __dax_fault() to do a full DAX page fault.

Really what the pfn_mkwrite() fault handler needs to do is call
dax_pfn_mkwrite() to make sure that the radix tree entry for the given
PTE is marked as dirty so that a follow-up fsync or msync call will
flush it durably to media.

Fixes: 5a023cdb ("block: enable dax for raw block devices")
Signed-off-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: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 823dd322

fs/block_dev.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -1730,6 +1730,12 @@ static int blkdev_dax_fault(struct vm_area_struct vma, struct vm_fault vmf)
		return __dax_fault(vma, vmf, blkdev_get_block, NULL);
		}

		static int blkdev_dax_pfn_mkwrite(struct vm_area_struct *vma,
		struct vm_fault *vmf)
		{
		return dax_pfn_mkwrite(vma, vmf);
		}

		static int blkdev_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
		pmd_t *pmd, unsigned int flags)
		{
		@@ -1739,7 +1745,7 @@ static int blkdev_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
		static const struct vm_operations_struct blkdev_dax_vm_ops = {
		.fault = blkdev_dax_fault,
		.pmd_fault = blkdev_dax_pmd_fault,
		.pfn_mkwrite = blkdev_dax_fault,
		.pfn_mkwrite = blkdev_dax_pfn_mkwrite,
		};

		static const struct vm_operations_struct blkdev_default_vm_ops = {