On Wed, Nov 25, 2020 at 01:29:53PM +0100, Jan Kara wrote: > > mutex_unlock(&bdev->bd_fsfreeze_mutex); > > - return sb; /* thaw_bdev releases s->s_umount */ > > + return error; /* thaw_bdev releases s->s_umount */ > > The comment about thaw_bdev() seems to be stale? At least I don't see what > it's speaking about... Yes, this comment seems long stale. I think in the very early days we held s_umount on frozen file system, which caused all kinds of problems. > > mutex_unlock(&bdev->bd_fsfreeze_mutex); > > - return error; > > + return 0; > > But we now won't return -EINVAL if this gets called e.g. with > bd_fsfreeze_count == 0, right? Yes. I had tried to drop the return value as all the freeze_bdev calls ignored it. But I had missed the unpaired emergency thaw and put it back and messed this up..