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

From: Jeff Layton
Date: Tue Jun 11 2013 - 07:14:37 EST


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@xxxxxxxxxx>
---
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

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