mainline inclusion
from mainline-5.1-rc4
commit 93b919da64c1
category: bugfix
bugzilla: 13537
CVE: NA

-------------------------------------------------

symlink body shouldn't be freed without an RCU delay.  Switch debugfs to
->destroy_inode() and use of call_rcu(); free both the inode and symlink
body in the callback.  Similar to solution for bpf, only here it's even
more obvious that ->evict_inode() can be dropped.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Nzhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>