On Sat, Jun 04, 2011 at 03:19:40PM +0100, Al Viro wrote: > > The iprune_sem removal is fine as soon as you have a per-sb shrinker > > for the inodes which keeps an active reference on the superblock until > > all the inodes are evicted. > > I really don't like that. Stuff keeping active refs, worse yet doing that > asynchronously... Shrinkers should *not* do that. Just grab a passive > ref (i.e. bump s_count), try grab s_umount (shared) and if that thing still > has ->s_root while we hold s_umount, go ahead. Unregister either at the > end of generic_shutdown_super() or from deactivate_locked_super(), between > the calls of ->kill_sb() and put_filesystem(). PS: shrinkers should not acquire active refs; more specifically, they should not _drop_ active refs, lest they end up dropping the last active one and trigger unregistering a shrinker for superblock in question. From inside of ->shrink(), with shrinker_rwsem held by caller. Deadlock... -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>