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