On Mon, Mar 23, 2015 at 02:54:40PM +0200, Boaz Harrosh wrote: > From: Boaz Harrosh <boaz@xxxxxxxxxxxxx> > > When freezing an FS, we must write protect all IS_DAX() > inodes that have an mmap mapping on an inode. Otherwise > application will be able to modify previously faulted-in > file pages. All you need to do is lock out page faults once the page is clean; that's what the sb_start_pagefault() calls are for in the page fault path - they catch write faults and block them until the filesystem is unfrozen. Hence I'm not sure why this would be necessary if you are catching write faults in .pfn_mkwrite.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>