From c0a5b560938a0f2fd2fbf66ddc446c7c2b41383a Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Thu, 12 Feb 2015 14:59:07 -0800 Subject: list_lru: organize all list_lrus to list To make list_lru memcg aware, we need all list_lrus to be kept on a list protected by a mutex, so that we could sleep while walking over the list. Therefore after this change list_lru_destroy may sleep. Fortunately, there is only one user that calls it from an atomic context - it's put_super - and we can easily fix it by calling list_lru_destroy before put_super in destroy_locked_super - anyway we don't longer need lrus by that time. Another point that should be noted is that list_lru_destroy is allowed to be called on an uninitialized zeroed-out object, in which case it is a no-op. Before this patch this was guaranteed by kfree, but now we need an explicit check there. Signed-off-by: Vladimir Davydov Cc: Dave Chinner Cc: Johannes Weiner Cc: Michal Hocko Cc: Greg Thelen Cc: Glauber Costa Cc: Alexander Viro Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/super.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'fs/super.c') diff --git a/fs/super.c b/fs/super.c index a2b735a42e74..b027849d92d2 100644 --- a/fs/super.c +++ b/fs/super.c @@ -282,6 +282,14 @@ void deactivate_locked_super(struct super_block *s) unregister_shrinker(&s->s_shrink); fs->kill_sb(s); + /* + * Since list_lru_destroy() may sleep, we cannot call it from + * put_super(), where we hold the sb_lock. Therefore we destroy + * the lru lists right now. + */ + list_lru_destroy(&s->s_dentry_lru); + list_lru_destroy(&s->s_inode_lru); + put_filesystem(fs); put_super(s); } else { -- cgit