xfs: clean up code layout in xfs_trans_ail.c

This patch rearranges the location of functions in xfs_trans_ail.c
to remove the need for forward declarations of those functions in
preparation for adding new functions without the need for forward
declarations.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>

1 files changed, 118 insertions, 136 deletions

diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index cb3aeac929bc..8012bfbc6dc0 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -30,41 +30,100 @@
 
 struct workqueue_struct *xfs_ail_wq;    /* AIL workqueue */
 
-STATIC void xfs_ail_splice(struct xfs_ail *, struct list_head *, xfs_lsn_t);
-STATIC void xfs_ail_delete(struct xfs_ail *, xfs_log_item_t *);
-STATIC xfs_log_item_t * xfs_ail_min(struct xfs_ail *);
-STATIC xfs_log_item_t * xfs_ail_next(struct xfs_ail *, xfs_log_item_t *);
-
 #ifdef DEBUG
-STATIC void xfs_ail_check(struct xfs_ail *, xfs_log_item_t *);
-#else
+/*
+ * Check that the list is sorted as it should be.
+ */
+STATIC void
+xfs_ail_check(
+        struct xfs_ail  *ailp,
+        xfs_log_item_t  *lip)
+{
+        xfs_log_item_t  *prev_lip;
+
+        if (list_empty(&ailp->xa_ail))
+                return;
+
+        /*
+         * Check the next and previous entries are valid.
+         */
+        ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
+        prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail);
+        if (&prev_lip->li_ail != &ailp->xa_ail)
+                ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
+
+        prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail);
+        if (&prev_lip->li_ail != &ailp->xa_ail)
+                ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0);
+
+
+#ifdef XFS_TRANS_DEBUG
+        /*
+         * Walk the list checking lsn ordering, and that every entry has the
+         * XFS_LI_IN_AIL flag set. This is really expensive, so only do it
+         * when specifically debugging the transaction subsystem.
+         */
+        prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
+        list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
+                if (&prev_lip->li_ail != &ailp->xa_ail)
+                        ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
+                ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
+                prev_lip = lip;
+        }
+#endif /* XFS_TRANS_DEBUG */
+}
+#else /* !DEBUG */
 #define xfs_ail_check(a,l)
 #endif /* DEBUG */
 
+/*
+ * Return a pointer to the first item in the AIL.  If the AIL is empty, then
+ * return NULL.
+ */
+static xfs_log_item_t *
+xfs_ail_min(
+        struct xfs_ail  *ailp)
+{
+        if (list_empty(&ailp->xa_ail))
+                return NULL;
+
+        return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
+}
+
+/*
+ * Return a pointer to the item which follows the given item in the AIL.  If
+ * the given item is the last item in the list, then return NULL.
+ */
+static xfs_log_item_t *
+xfs_ail_next(
+        struct xfs_ail  *ailp,
+        xfs_log_item_t  *lip)
+{
+        if (lip->li_ail.next == &ailp->xa_ail)
+                return NULL;
+
+        return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail);
+}
 
 /*
- * This is called by the log manager code to determine the LSN
- * of the tail of the log.  This is exactly the LSN of the first
- * item in the AIL.  If the AIL is empty, then this function
- * returns 0.
+ * This is called by the log manager code to determine the LSN of the tail of
+ * the log.  This is exactly the LSN of the first item in the AIL.  If the AIL
+ * is empty, then this function returns 0.
  *
- * We need the AIL lock in order to get a coherent read of the
- * lsn of the last item in the AIL.
+ * We need the AIL lock in order to get a coherent read of the lsn of the last
+ * item in the AIL.
  */
 xfs_lsn_t
 xfs_trans_ail_tail(
         struct xfs_ail  *ailp)
 {
-        xfs_lsn_t       lsn;
+        xfs_lsn_t       lsn = 0;
         xfs_log_item_t  *lip;
 
         spin_lock(&ailp->xa_lock);
         lip = xfs_ail_min(ailp);
-        if (lip == NULL) {
-                lsn = (xfs_lsn_t)0;
-        } else {
+        if (lip)
                 lsn = lip->li_lsn;
-        }
         spin_unlock(&ailp->xa_lock);
 
         return lsn;
@@ -208,6 +267,47 @@ out:
 }
 
 /*
+ * splice the log item list into the AIL at the given LSN.
+ */
+static void
+xfs_ail_splice(
+        struct xfs_ail  *ailp,
+        struct list_head *list,
+        xfs_lsn_t       lsn)
+{
+        xfs_log_item_t  *next_lip;
+
+        /* If the list is empty, just insert the item.  */
+        if (list_empty(&ailp->xa_ail)) {
+                list_splice(list, &ailp->xa_ail);
+                return;
+        }
+
+        list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) {
+                if (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0)
+                        break;
+        }
+
+        ASSERT(&next_lip->li_ail == &ailp->xa_ail ||
+               XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0);
+
+        list_splice_init(list, &next_lip->li_ail);
+}
+
+/*
+ * Delete the given item from the AIL.  Return a pointer to the item.
+ */
+static void
+xfs_ail_delete(
+        struct xfs_ail  *ailp,
+        xfs_log_item_t  *lip)
+{
+        xfs_ail_check(ailp, lip);
+        list_del(&lip->li_ail);
+        xfs_trans_ail_cursor_clear(ailp, lip);
+}
+
+/*
  * xfs_ail_worker does the work of pushing on the AIL. It will requeue itself
  * to run at a later time if there is more work to do to complete the push.
  */
@@ -657,121 +757,3 @@ xfs_trans_ail_destroy(
         cancel_delayed_work_sync(&ailp->xa_work);
         kmem_free(ailp);
 }
-
-/*
- * splice the log item list into the AIL at the given LSN.
- */
-STATIC void
-xfs_ail_splice(
-        struct xfs_ail  *ailp,
-        struct list_head *list,
-        xfs_lsn_t       lsn)
-{
-        xfs_log_item_t  *next_lip;
-
-        /*
-         * If the list is empty, just insert the item.
-         */
-        if (list_empty(&ailp->xa_ail)) {
-                list_splice(list, &ailp->xa_ail);
-                return;
-        }
-