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: > > 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!
