fs/locks: rename some lists and pointers.

struct file lock contains an 'fl_next' pointer which
is used to point to the lock that this request is blocked
waiting for.  So rename it to fl_blocker.

The fl_blocked list_head in an active lock is the head of a list of
blocked requests.  In a request it is a node in that list.
These are two distinct uses, so replace with two list_heads
with different names.
fl_blocked_requests is the head of a list of blocked requests
fl_blocked_member is a node in a member of that list.

The two different list_heads are never used at the same time, but that
will change in a future patch.

Note that a tracepoint is changed to report fl_blocker instead
of fl_next.

Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

1 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index c95c0807471f..16df3a7df378 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1044,10 +1044,15 @@ bool opens_in_grace(struct net *);
  * Obviously, the last two criteria only matter for POSIX locks.
  */
 struct file_lock {
-        struct file_lock *fl_next;      /* singly linked list for this inode  */
+        struct file_lock *fl_blocker;   /* The lock, that is blocking us */
         struct list_head fl_list;       /* link into file_lock_context */
         struct hlist_node fl_link;      /* node in global lists */
-        struct list_head fl_block;      /* circular list of blocked processes */
+        struct list_head fl_blocked_requests;   /* list of requests with
+                                                 * ->fl_blocker pointing here
+                                                 */
+        struct list_head fl_blocked_member;     /* node in
+                                                 * ->fl_blocker->fl_blocked_requests
+                                                 */
         fl_owner_t fl_owner;
         unsigned int fl_flags;
         unsigned char fl_type;