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

Dave Chinner
2011-07-04T05:27:48Z

From: Dave Chinner <dchinner@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@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