On Wed, Jun 19, 2019 at 7:55 PM Guoqing Jiang <gqjiang@xxxxxxxx> wrote: > > > > On 6/20/19 1:28 AM, Song Liu wrote: > > On Wed, Jun 19, 2019 at 2:10 AM Guoqing Jiang <gqjiang@xxxxxxxx> wrote: > >> > >> For write-behind mode, we think write IO is complete once it has > >> reached all the non-writemostly devices. It works fine for single > >> queue devices. > >> > >> But for multiqueue device, if there are lots of IOs come from upper > >> layer, then the write-behind device could issue those IOs to different > >> queues, depends on the each queue's delay, so there is no guarantee > >> that those IOs can arrive in order. > >> > >> To address the issue, we need to check the collision among write > >> behind IOs, we can only continue without collision, otherwise wait > >> for the completion of previous collisioned IO. > >> > >> And WBCollision is introduced for multiqueue device which is worked > >> under write-behind mode. > >> > >> But this patch doesn't handle below cases which could have the data > >> inconsistency issue as well, these cases will be handled in later > >> patches. > >> > >> 1. modify max_write_behind by write backlog node. > >> 2. add or remove array's bitmap dynamically. > >> 3. the change of member disk. > >> > >> Reviewed-by: NeilBrown <neilb@xxxxxxxx> > >> Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx> > > > > Applied to https://github.com/liu-song-6/linux/tree/md-next > > > > Thanks Guoqing! > > > > Thanks Song! BTW, maybe you need to update the git tree information in > MAINTAINER file, then people can track md tree well. I am asking for a kernel.org repo. I will update it once that is done. > > And could you take a look at other 4 patches as well? Thanks. Will do. Thanks, Song
