Re: [RFC][PATCH v2 0/5] Experiments with overlayfs filemap

Vivek Goyal
2019-02-01T16:29:27Z

On Fri, Feb 01, 2019 at 03:22:34PM +0200, Amir Goldstein wrote:

[..]
> New lazy copy up semantics:
> overlay/060

Right now we open file with O_APPEND to make sure data is copied up. We
could probably change that to write some data to file and then make sure
file is copied up? Anyway, we are not promising that file will definitely
get copied up after opening with O_RDWR or O_APPEND.

And could add some tests for lazy copy up to make sure opening file
with O_RDWR alone does not do data copy up. (If lazy copy up is
enabled).

Vivek