ext4: add ext4_dax_pfn_mkwrite()

Add ext4_dax_pfn_mkwrite() that properly protects against freeze, sets
the file update time and calls into dax_pfn_mkwrite() to add the newly
dirtied page to the radix tree which tracks dirty DAX pages.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
1 file changed