> The above patch fixes an issue with ext4 where executables cannot be run on > read-only filesystems mounted with the DAX option. > > This issue does not appear to be present in ext2 or XFS, as they both pass > the test. I've also confirmed outside of the test that they are both > indeed able to execute binaries on read-only DAX mounts. It works for me on XFS. But I don't really understand why, as the fault handler doesn't look very different. Maybe the problem is that in ext4_journal_start_sb will fail on a read-only fs? Even for xfs/ext2 it would seem odd that things like sb_start_pagefault just work. > +LS=$(which ls --skip-alias --skip-functions) 2>/dev/null > +if [ $? -ne 0 ]; then > + status=$? > + echo "Couldn't find 'ls'!?" > + exit > +fi These checks all fail for me..