Re: [PATCH 2/2] zram: do not count duplicated pages as compressed

On Sun, May 21, 2017 at 12:04:27AM -0700, Christoph Hellwig wrote:

On Wed, May 17, 2017 at 05:32:12PM +0900, Minchan Kim wrote:

quoted

Is block device(esp, zram which is compressed ram block device) okay to
return garbage when ongoing overwrite IO fails?

O_DIRECT write 4 block "aaa.." -> success
read  4 block "aaa.." -> success
O_DIRECT write 4 block "bbb.." -> fail
read  4 block "000..' -> it is okay?

Hope to get an answer form experts. :)

It's "okay" as it's what existing real block devices do (at least on a
sector boundary).  It's not "nice" though, so if you can avoid it,
please do.

That was my understanding so I wanted to avoid it for just simple
code refactoring. Your comment helps to confirm the thhought.

Thanks, Christoph!