Currently if we face a lock taken by a process invisible in the current
pidns we skip the lock completely, but this
1) makes the output not that nice
(root@vz7)/: cat /proc/${PID_A2}/fdinfo/3
pos: 4
flags: 02100002
mnt_id: 257
lock: (root@vz7)/:
2) makes it more difficult to debug issues with leaked flocks
if you get error on lock, but don't see any locks in /proc/$id/fdinfo/$file
Let's show information about such locks again as previously, but
show zero in the owner pid field.
After the patch:
===============
(root@vz7)/:cat /proc/${PID_A2}/fdinfo/3
pos: 4
flags: 02100002
mnt_id: 295
lock: 1: FLOCK ADVISORY WRITE 0 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 <khorenko@xxxxxxxxxxxxx>
---
fs/locks.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index bfee5b7f2862..e533623e2e99 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2633,12 +2633,10 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
fl_pid = locks_translate_pid(fl, proc_pidns);
/*
- * If there isn't a fl_pid don't display who is waiting on
- * the lock if we are called from locks_show, or if we are
- * called from __show_fd_info - skip lock entirely
+ * If lock owner is dead (and pid is freed) or not visible in current
+ * pidns, zero is shown as a pid value. Check lock info from
+ * init_pid_ns to get saved lock pid value.
*/
- if (fl_pid == 0)
- return;
if (fl->fl_file != NULL)
inode = locks_inode(fl->fl_file);
--
2.15.1
