make sure that mntns_install() doesn't end up with referral for root
authorAl Viro <viro@zeniv.linux.org.uk>
Sat, 15 Apr 2017 21:31:22 +0000 (17:31 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Fri, 21 Apr 2017 18:05:36 +0000 (14:05 -0400)
commit4f757f3cbf54edef7b75c68d6d6d2f1a0ca08d2e
treeea39abd6e1941de602264b24ee18c82f12c01c04
parent93893862fb7ba704ec5a6872a294c9cc2b0d4ca3
make sure that mntns_install() doesn't end up with referral for root

new flag: LOOKUP_DOWN.  If the starting point is overmounted, cross
into whatever's mounted on top, triggering referrals et.al.

Use that instead of follow_down_one() loop in mntns_install(), handle
errors properly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/namei.c
fs/namespace.c
include/linux/namei.h