[PATCH 8/8] xfs: use AIL bulk delete function to implement single delete

[Dave Chinner]

From: Dave Chinner <dchinner at redhat.com>

We now have two copies of AIL delete operations that are mostly
duplicate functionality. The single log item deletes can be
implemented via the bulk updates by turning xfs_trans_ail_delete()
into a simple wrapper. This removes all the duplicate delete
functionality and associated helpers.

Signed-off-by: Dave Chinner <dchinner at redhat.com>
---
 fs/xfs/xfs_trans_ail.c  |   70 +++-------------------------------------------
 fs/xfs/xfs_trans_priv.h |   20 +++++++++-----
 2 files changed, 18 insertions(+), 72 deletions(-)

diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index 2f44f92..91aaf7b 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -520,80 +520,21 @@ xfs_trans_ail_update_bulk(
 }
 
 /*
- * Delete the given item from the AIL.  It must already be in
- * the AIL.
- *
- * Wakeup anyone with an lsn less than item's lsn.    If the item
- * we delete in the AIL is the minimum one, update the tail lsn in the
- * log manager.
- *
- * Clear the IN_AIL flag from the item, reset its lsn to 0, and
- * bump the AIL's generation count to indicate that the tree
- * has changed.
- *
- * This function must be called with the AIL lock held.  The lock
- * is dropped before returning.
- */
-void
-xfs_trans_ail_delete(
-	struct xfs_ail	*ailp,
-	xfs_log_item_t	*lip) __releases(ailp->xa_lock)
-{
-	xfs_log_item_t		*mlip;
-	xfs_lsn_t		tail_lsn;
-
-	if (lip->li_flags & XFS_LI_IN_AIL) {
-		mlip = xfs_ail_min(ailp);
-		xfs_ail_delete(ailp, lip);
-
-
-		lip->li_flags &= ~XFS_LI_IN_AIL;
-		lip->li_lsn = 0;
-
-		if (mlip == lip) {
-			mlip = xfs_ail_min(ailp);
-			/*
-			 * It is not safe to access mlip after the AIL lock
-			 * is dropped, so we must get a copy of li_lsn
-			 * before we do so.  This is especially important
-			 * on 32-bit platforms where accessing and updating
-			 * 64-bit values like li_lsn is not atomic.
-			 */
-			tail_lsn = mlip ? mlip->li_lsn : 0;
-			spin_unlock(&ailp->xa_lock);
-			xfs_log_move_tail(ailp->xa_mount, tail_lsn);
-		} else {
-			spin_unlock(&ailp->xa_lock);
-		}
-	}
-	else {
-		/*
-		 * If the file system is not being shutdown, we are in
-		 * serious trouble if we get to this stage.
-		 */
-		struct xfs_mount	*mp = ailp->xa_mount;
-
-		spin_unlock(&ailp->xa_lock);
-		if (!XFS_FORCED_SHUTDOWN(mp)) {
-			xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp,
-		"%s: attempting to delete a log item that is not in the AIL",
-					__func__);
-			xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
-		}
-	}
-}
-
-/*
  * Bulk update version of xfs_trans_ail_delete
  *
  * This version takes an array of log items that all need to removed from the
  * AIL. The caller is already holding the AIL lock, and done all the checks
  * necessary to ensure the items passed in via @lgia are ready for deletion.
+ * If an item we delete in the AIL is the minimum one, update the tail lsn in
+ * the log manager.
  *
  * This function will not drop the AIL lock until all items are removed from
  * the AIL to minimise the amount of lock traffic on the AIL. This does not
  * greatly increase the AIL hold time, but does significantly reduce the amount
  * of traffic on the lock, especially during IO completion.
+ *
+ * This function must be called with the AIL lock held.  The lock is dropped
+ * before returning.
  */
 void
 xfs_trans_ail_delete_bulk(
@@ -648,7 +589,6 @@ xfs_trans_ail_delete_bulk(
 	xfs_log_move_tail(ailp->xa_mount, tail_lsn);
 }
 
-
 /*
  * The active item list (AIL) is a doubly linked list of log
  * items sorted by ascending lsn.  The base of the list is
diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
index 1cf42e7..2bd3c19 100644
--- a/fs/xfs/xfs_trans_priv.h
+++ b/fs/xfs/xfs_trans_priv.h
@@ -89,13 +89,19 @@ xfs_trans_ail_update(
 	xfs_trans_ail_update_bulk(ailp, lgia, 1, lsn);
 }
 
-void			xfs_trans_ail_delete(struct xfs_ail *ailp,
-					struct xfs_log_item *lip)
-					__releases(ailp->xa_lock);
-void			xfs_trans_ail_delete_bulk(struct xfs_ail *ailp,
-					struct xfs_log_item **lgia,
-					int nr_items)
-					__releases(ailp->xa_lock);
+void	xfs_trans_ail_delete_bulk(struct xfs_ail *ailp,
+				struct xfs_log_item **lgia, int nr_items)
+				__releases(ailp->xa_lock);
+static inline void
+xfs_trans_ail_delete(
+	struct xfs_ail	*ailp,
+	xfs_log_item_t	*lip) __releases(ailp->xa_lock)
+{
+	struct xfs_log_item	*lgia[1] = { lip, };
+
+	xfs_trans_ail_delete_bulk(ailp, lgia, 1);
+}
+
 void			xfs_trans_ail_push(struct xfs_ail *, xfs_lsn_t);
 void			xfs_trans_unlocked_item(struct xfs_ail *,
 					xfs_log_item_t *);
-- 
1.7.2.3