From: Dan Williams [mailto:dan.j.williams@xxxxxxxxx] > A couple weeks back, in the course of reviewing the memcpy_nocache() > proposal from Brian, Linus subtly suggested that the pmem specific > memcpy_to_pmem() routine be moved to be implemented at the driver > level [1]: Of course, there may not be a backing device either! That will depend on the filesystem. I see two possible routes here: 1. Add a new address_space_operation: const struct dax_operations *(*get_dax_ops)(struct address_space *); 2. Add two of the dax_operations to address_space_operations: size_t (*copy_from_iter)(struct address_space *, void *, size_t, struct iov_iter *); void (*flush)(struct address_space *, void *, size_t); (we won't need ->direct_access as an address_space op because that'll be handled a different way in the brave new world that supports non-bdev-based filesystems) Obviously in either case we'd have generic bdev versions for ext4, xfs and other block based filesystems, but filesystems with a character device or a network protocol behind them would do whatever it is they need to do. I kind of prefer the second option, but does anyone else have a preference? -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
