Re: [RFC] nvfs: a filesystem for persistent memory

[Matthew Wilcox]

On Tue, Sep 15, 2020 at 08:34:41AM -0400, Mikulas Patocka wrote:
> - when the fsck.nvfs tool mmaps the device /dev/pmem0, the kernel uses 
> buffer cache for the mapping. The buffer cache slows does fsck by a factor 
> of 5 to 10. Could it be possible to change the kernel so that it maps DAX 
> based block devices directly?

Oh, because fs/block_dev.c has:
        .mmap           = generic_file_mmap,

I don't see why we shouldn't have a blkdev_mmap modelled after
ext2_file_mmap() with the corresponding blkdev_dax_vm_ops.