[PATCH v2 06/14] locks: don't walk inode->i_flock list in locks_show

[Jeff Layton <jlayton@redhat.com>]

When we convert over to using the i_lock to protect the i_flock list,
that will introduce a potential lock inversion problem in locks_show.
When we want to walk the i_flock list, we'll need to take the i_lock.

Rather than do that, just walk the global blocked_locks list and print
out any that are blocked on the given lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/locks.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index e451d18..3fd27f0 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2249,8 +2249,10 @@ static int locks_show(struct seq_file *f, void *v)
 
 	lock_get_status(f, fl, *((loff_t *)f->private), "");
 
-	list_for_each_entry(bfl, &fl->fl_block, fl_block)
-		lock_get_status(f, bfl, *((loff_t *)f->private), " ->");
+	list_for_each_entry(bfl, &blocked_list, fl_link) {
+		if (bfl->fl_next == fl)
+			lock_get_status(f, bfl, *((loff_t *)f->private), " ->");
+	}
 
 	return 0;
 }
-- 
1.7.1