> unsigned (*mmap_capabilities)(struct file *);
> #endif
> ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, size_t, unsigned int);
> - int (*clone_file_range)(struct file *, loff_t, struct file *, loff_t, u64);
> - int (*dedupe_file_range)(struct file *, loff_t, struct file *, loff_t, u64);
> + int (*remap_file_range)(struct file *file_in, loff_t pos_in,
> + struct file *file_out, loff_t pos_out,
> + u64 len, unsigned int remap_flags);
None of the other methods in this file name their parameters. While
I generally don't like people leaving them out, in the end consistency
is even more important.
> +int btrfs_remap_file_range(struct file *src_file, loff_t off,
> + struct file *dst_file, loff_t destoff, u64 len,
> + unsigned int remap_flags)
> {
> + if (!remap_check_flags(remap_flags, RFR_SAME_DATA))
> + return -EINVAL;
> +
> + if (remap_flags & RFR_SAME_DATA) {
So at least for btrfs there seems to be no shared code at all below
the function calls. This kinda speaks against the argument that
they fundamentally are the same..
> +/*
> + * These flags control the behavior of the remap_file_range function pointer.
> + *
> + * RFR_SAME_DATA: only remap if contents identical (i.e. deduplicate)
> + */
> +#define RFR_SAME_DATA (1 << 0)
> +
> +#define RFR_VALID_FLAGS (RFR_SAME_DATA)
RFR? Why not REMAP_FILE_* Also why not the well understood
REMAP_FILE_DEDUP instead of the odd SAME_DATA?
> +
> +/*
> + * Filesystem remapping implementations should call this helper on their
> + * remap flags to filter out flags that the implementation doesn't support.
> + *
> + * Returns true if the flags are ok, false otherwise.
> + */
> +static inline bool remap_check_flags(unsigned int remap_flags,
> + unsigned int supported_flags)
> +{
> + return (remap_flags & ~(supported_flags & RFR_VALID_FLAGS)) == 0;
> +}
Any reason to even bother with a helper for this? ->fallocate
seems to be doing fine without the helper, and the resulting code
seems a lot easier to understand to me.
> @@ -1759,10 +1779,9 @@ struct file_operations {
> #endif
> ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
> loff_t, size_t, unsigned int);
> - int (*clone_file_range)(struct file *, loff_t, struct file *, loff_t,
> - u64);
> - int (*dedupe_file_range)(struct file *, loff_t, struct file *, loff_t,
> - u64);
> + int (*remap_file_range)(struct file *file_in, loff_t pos_in,
> + struct file *file_out, loff_t pos_out,
> + u64 len, unsigned int remap_flags);
Same comment here. Didn't we have some nice doc tools to avoid this
duplication? :)
