Re: [PATCH 3/3] f2fs: support clone_file_range

On Mon, Jul 18, 2016 at 08:47:36PM -0700, Christoph Hellwig wrote:

On Sat, Jul 16, 2016 at 11:24:27PM -0700, Jaegeuk Kim wrote:

quoted

This patch implements clone_file_range in f2fs.

[...]

quoted

+int f2fs_clone_file_range(struct file *file_in, loff_t pos_in,
+		struct file *file_out, loff_t pos_out, u64 len)
+{
+	return f2fs_clone_files(file_in, pos_in, file_out, pos_out, len);
+}
+

Falling back from copy to clone should be done in the VFS.  I look into
implementing the fallback, and the code is trivial, but we don't seem
to have any useful coverage for copy_file_range yet, so I didn't dare
to add it yet.  How did you test copy and clone in f2fs?  And how did
you handle the difference in corner cases (e.g. the lacking 0 special
case in copy)?

Frankly speaking, I confused the behaviors without being aware of corner cases.
And thus, I dropped the patches already. Instead, I realized that what I did
was moving a range of blocks from one file to another file. So, I've been
testing a new ioctl, F2FS_IOC_MOVE_RANGE.
In terms of coverage, I just did some unit tests only.

Thanks,

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