On Thu 13-08-15 15:36:16, Oleg Nesterov wrote: > On 08/13, Jan Kara wrote: > > > > On Tue 11-08-15 19:04:16, Oleg Nesterov wrote: > > > > > > So this is just the temporary kludge which helps us to avoid the > > > conflicts with the changes which will be (hopefully) routed via > > > rcu tree. > > > > > > Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> > > > > Looking into this again, it would seem somewhat cleaner to me to move the > > destruction to deactivate_locked_super() instead. > > Heh ;) You know, I was looking at deactivate_locked_super(). However, I > simply do not understand this code enough, I failed to verify it would > be safe to destroy s_writers there. Yes, it will be safe. After ->kill_sb() callback the filesystem is dead. There can be someone still holding reference to superblock but these are just users inspecting the structure definitely not caring about freeze protection. > And. Please note destroy_super() in alloc_super() error path, so this > needs a bit more changes in any case. Yes. But you can sleep in alloc_super() so that would be easy enough. > Can't we live with this hack for now? To remind, it will be reverted > (at least partially) in any case. Yes, yes, it is very ugly and the > changelog documents this fact. But it looks simple and safe. To me > it would be better to make the conversion first, then cleanup this > horror after another discussion. All I care about is that long-term, all handling from destroy_super() that needs to sleep ends up in one place. So if you promise you'll make this happen I can live with the workqueue solution for now (but you have to convince also Al as a maintainer ;). Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
