[PATCH 3/3 v3] kernel: set_groups doesn't call groups_sort anymore.

From: Thiago Rafael Becker
Date: Tue Dec 05 2017 - 09:05:54 EST


When the group_info is cached (e.g. sunrpc) there's the possibility
that threads calling set_groups will attempt to do so simultaneously.

Moving the responsibility of sorting to the caller of set_groups, or
in the case of nfsd, to the point where it is received from rpc.mountd
avoids this issue.

Moving it to the caller has the added benifit of a slight improvement on
the nfsd performance.

Signed-off-by: Thiago Rafael Becker <thiago.becker@xxxxxxxxx>
---
kernel/groups.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/kernel/groups.c b/kernel/groups.c
index 17073a9..8620ad3 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -124,7 +124,6 @@ int groups_search(const struct group_info *group_info, kgid_t grp)
void set_groups(struct cred *new, struct group_info *group_info)
{
put_group_info(new->group_info);
- groups_sort(group_info);
get_group_info(group_info);
new->group_info = group_info;
}
--
2.9.5