[PATCH 3/5] xfs: remove confusing ail cursor wrapper

[Dave Chinner]

From: Dave Chinner <dchinner at redhat.com>

xfs_trans_ail_cursor_set() doesn't set the cursor to the current log
item, it sets it to the next item. There is already a function for
doing this - xfs_trans_ail_cursor_next() - and the _set function is
simply a two line wrapper.  Remove it and open code the setting of
the cursor in the two locations that call it to remove the
confusion.

Signed-off-by: Dave Chinner <dchinner at redhat.com>
---
 fs/xfs/xfs_trans_ail.c |   38 ++++++++++++--------------------------
 1 files changed, 12 insertions(+), 26 deletions(-)

diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index 272e7fa..de7a52a 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -189,20 +189,6 @@ xfs_trans_ail_cursor_init(
 }
 
 /*
- * Set the cursor to the next item, because when we look
- * up the cursor the current item may have been freed.
- */
-STATIC void
-xfs_trans_ail_cursor_set(
-	struct xfs_ail		*ailp,
-	struct xfs_ail_cursor	*cur,
-	struct xfs_log_item	*lip)
-{
-	if (lip)
-		cur->item = xfs_ail_next(ailp, lip);
-}
-
-/*
  * Get the next item in the traversal and advance the cursor.
  * If the cursor was invalidated (inidicated by a lip of 1),
  * restart the traversal.
@@ -216,7 +202,8 @@ xfs_trans_ail_cursor_next(
 
 	if ((__psint_t)lip & 1)
 		lip = xfs_ail_min(ailp);
-	xfs_trans_ail_cursor_set(ailp, cur, lip);
+	if (lip)
+		cur->item = xfs_ail_next(ailp, lip);
 	return lip;
 }
 
@@ -272,9 +259,10 @@ xfs_trans_ail_cursor_clear(
 }
 
 /*
- * Initialise the cursor to the first item in the AIL with the given @lsn.
- * This searches the list from lowest LSN to highest. Pass a @lsn of zero
- * to initialise the cursor to the first item in the AIL.
+ * Find the first item in the AIL with the given @lsn by searching in ascending
+ * LSN order and initialise the cursor to point to the next item for a
+ * ascending traversal.  Pass a @lsn of zero to initialise the cursor to the
+ * first item in the AIL. Returns NULL if the list is empty.
  */
 xfs_log_item_t *
 xfs_trans_ail_cursor_first(
@@ -295,14 +283,11 @@ xfs_trans_ail_cursor_first(
 	}
 	lip = NULL;
 out:
-	xfs_trans_ail_cursor_set(ailp, cur, lip);
+	if (lip)
+		cur->item = xfs_ail_next(ailp, lip);
 	return lip;
 }
 
-/*
- * Initialise the cursor to the last item in the AIL with the given @lsn.
- * This searches the list from highest LSN to lowest.
- */
 static struct xfs_log_item *
 __xfs_trans_ail_cursor_last(
 	struct xfs_ail		*ailp,
@@ -329,8 +314,9 @@ out:
 }
 
 /*
- * Initialise the cursor to the last item in the AIL with the given @lsn.
- * This searches the list from highest LSN to lowest.
+ * Find the last item in the AIL with the given @lsn by searching in descending
+ * LSN order and initialise the cursor to point to that item.  Returns NULL is
+ * the list is empty.
  */
 struct xfs_log_item *
 xfs_trans_ail_cursor_last(
@@ -342,7 +328,7 @@ xfs_trans_ail_cursor_last(
 }
 
 /*
- * splice the log item list into the AIL at the given LSN. We splice to the
+ * Splice the log item list into the AIL at the given LSN. We splice to the
  * tail of the given LSN to maintain insert order for push traversals. The
  * cursor is optional, allowing repeated updates to the same LSN to avoid
  * repeated traversals.
-- 
1.7.5.1