Tang Junhui-- Thanks for noticing this issue. On Wed, Nov 1, 2017 at 4:55 AM, Coly Li <i@xxxxxxx> wrote: > On 2017/10/31 下午4:14, tang.junhui@xxxxxxxxxx wrote: >> From: Tang Junhui <tang.junhui@xxxxxxxxxx> >> >> Currently, when a cached device detaching from cache, writeback thread is not stopped, >> and writeback_rate_update work is not canceled. For example, after bellow command: >> echo 1 >/sys/block/sdb/bcache/detach >> you can still see the writeback thread. Then you attach the device to the cache again, >> bcache will create another writeback thread, for example, after bellow command: >> echo ba0fb5cd-658a-4533-9806-6ce166d883b9 > /sys/block/sdb/bcache/attach >> then you will see 2 writeback threads. >> This patch stops writeback thread and cancels writeback_rate_update work when cached >> device detaching from cache. >> >> Signed-off-by: Tang Junhui <tang.junhui@xxxxxxxxxx> > > If the change can be inside bch_register_lock, it would (just) be more > comfortable. The code is correct, because attach/detach sysfs is created > after writeback_thread created and writeback_rate_update worker > initialized, even these resources are initialized within > bch_register_lock and released out of bch)register_lock in your patch, > there won't be any race. It's OK to me. > I think I agree with Coly that I'd prefer it to be moved down into the register lock, as I think that will be safer with any future changes. Are you willing to adjust it this way? Thanks, Mike
