Merge tag 'modules-for-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu...

[linux.git] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index db7b6917d9c52d52d981efca3eb36f17149a0712..bc047a7edc476e96d6e6a729de2884c292f4dc72 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -202,10 +202,6 @@ static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS);
  * we often hold the flc_lock as well. In certain cases, when reading the fields
  * protected by this lock, we can skip acquiring it iff we already hold the
  * flc_lock.
- *
- * In particular, adding an entry to the fl_block list requires that you hold
- * both the flc_lock and the blocked_lock_lock (acquired in that order).
- * Deleting an entry from the list however only requires the file_lock_lock.
  */
 static DEFINE_SPINLOCK(blocked_lock_lock);
 
@@ -990,6 +986,7 @@ out:
        if (new_fl)
                locks_free_lock(new_fl);
        locks_dispose_list(&dispose);
+       trace_flock_lock_inode(inode, request, error);
        return error;
 }
 
@@ -2072,6 +2069,13 @@ 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);
@@ -2626,12 +2630,10 @@ 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);