Re: [PATCH v4 5/5] xfs: disable map_sync for async flush

> All this ad hoc IS_DAX conditional logic is getting pretty nasty. > > xfs_file_mmap( > .... > { > struct inode *inode = file_inode(filp); > > if (vma->vm_flags & VM_SYNC) { > if (!IS_DAX(inode)) > return -EOPNOTSUPP; > if (!dax_synchronous(xfs_find_daxdev_for_inode(inode)) > return -EOPNOTSUPP; > } > > file_accessed(filp); > vma->vm_ops = &xfs_file_vm_ops; > if (IS_DAX(inode)) > vma->vm_flags |= VM_HUGEPAGE; > return 0; > } Sure, this is better.

> Even better, factor out all the "MAP_SYNC supported" checks into a > helper so that the filesystem code just doesn't have to care about > the details of checking for DAX+MAP_SYNC support.... o.k. Will add one common helper function for both ext4 & xfs filesystems.