On Wed, Jun 28, 2023 at 2:29 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote: > > Hi, > > 在 2023/06/28 9:29, Yu Kuai 写道: > > From: Yu Kuai <yukuai3@xxxxxxxxxx> > > > > Some levels doesn't implement "pers->quiesce", for example > > raid0_quiesce() is empty, and now that all levels will drop 'active_io' > > until io is done, wait for 'active_io' to be 0 is enough to make sure all > > normal io is done, and percpu_ref_kill() for 'active_io' will make sure > > no new normal io can be dispatched. There is no need to call > > "pers->quiesce" anymore from mddev_suspend(). > > Just found that this patch actually prevent null_ptr_deref in some cases > that "pers->quiesce" is NULl for some personalities, and caller of > mddev_suspend() doesn't check this. For example, suspend_lo_store() > checks "pers->quiesce" is not NULL before calling mddev_suspend(), while > suspend_hi_store() doesn't. Let's refactor the code so that suspend_lo_store() and suspend_hi_store() share code for this logic. Thanks, Song
