From 826d7bc9f013d01e92997883d2fd0c25f4af1f1c Mon Sep 17 00:00:00 2001 From: Konstantin Khorenko Date: Fri, 8 Jun 2018 17:27:11 +0300 Subject: fs/lock: skip lock owner pid translation in case we are in init_pid_ns If the flock owner process is dead and its pid has been already freed, pid translation won't work, but we still want to show flock owner pid number when expecting /proc/$PID/fdinfo/$FD in init pidns. Reproducer: process A process A1 process A2 fork()---------> exit() open() flock() fork()---------> exit() sleep() Before the patch: ================ (root@vz7)/: cat /proc/${PID_A2}/fdinfo/3 pos: 4 flags: 02100002 mnt_id: 257 lock: (root@vz7)/: After the patch: =============== (root@vz7)/:cat /proc/${PID_A2}/fdinfo/3 pos: 4 flags: 02100002 mnt_id: 295 lock: 1: FLOCK ADVISORY WRITE ${PID_A1} b6:f8a61:529946 0 EOF Fixes: 9d5b86ac13c5 ("fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks") Signed-off-by: Konstantin Khorenko Acked-by: Andrey Vagin Reviewed-by: Benjamin Coddington Signed-off-by: Jeff Layton --- fs/locks.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'fs/locks.c') diff --git a/fs/locks.c b/fs/locks.c index 05e211be8684..bfee5b7f2862 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2072,6 +2072,13 @@ static pid_t locks_translate_pid(struct file_lock *fl, struct pid_namespace *ns) return -1; if (IS_REMOTELCK(fl)) return fl->fl_pid; + /* + * If the flock owner process is dead and its pid has been already + * freed, the translation below won't work, but we still want to show + * flock owner pid number in init pidns. + */ + if (ns == &init_pid_ns) + return (pid_t)fl->fl_pid; rcu_read_lock(); pid = find_pid_ns(fl->fl_pid, &init_pid_ns); -- cgit v1.2.3-59-g8ed1b