4 files changed, 195 insertions, 12 deletions

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index 23d6ceb..f36f1a2 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -361,15 +361,10 @@ xlog_cil_committed(
 	int	abort)
 {
 	struct xfs_cil_ctx	*ctx = args;
-	struct xfs_log_vec	*lv;
-	int			abortflag = abort ? XFS_LI_ABORTED : 0;
 	struct xfs_busy_extent	*busyp, *n;
 
-	/* unpin all the log items */
-	for (lv = ctx->lv_chain; lv; lv = lv->lv_next ) {
-		xfs_trans_item_committed(lv->lv_item, ctx->start_lsn,
-							abortflag);
-	}
+	xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain,
+					ctx->start_lsn, abort);
 
 	list_for_each_entry_safe(busyp, n, &ctx->busy_extents, list)
 		xfs_alloc_busy_clear(ctx->cil->xc_log->l_mp, busyp);
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index f6d956b..f80a067 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -1350,7 +1350,7 @@ xfs_trans_fill_vecs(
  * they could be immediately flushed and we'd have to race with the flusher
  * trying to pull the item from the AIL as we add it.
  */
-void
+static void
 xfs_trans_item_committed(
 	struct xfs_log_item	*lip,
 	xfs_lsn_t		commit_lsn,
@@ -1425,6 +1425,83 @@ xfs_trans_committed(
 	xfs_trans_free(tp);
 }
 
+static inline void
+xfs_log_item_batch_insert(
+	struct xfs_ail		*ailp,
+	struct xfs_log_item	**log_items,
+	int			nr_items,
+	xfs_lsn_t		commit_lsn)
+{
+	int	i;
+
+	spin_lock(&ailp->xa_lock);
+	/* xfs_trans_ail_update_bulk drops ailp->xa_lock */
+	xfs_trans_ail_update_bulk(ailp, log_items, nr_items, commit_lsn);
+
+	for (i = 0; i < nr_items; i++)
+		IOP_UNPIN(log_items[i], 0);
+}
+
+/*
+ * Bulk operation version of xfs_trans_committed that takes a log vector of
+ * items to insert into the AIL. This uses bulk AIL insertion techniques to
+ * minimise lock traffic.
+ */
+void
+xfs_trans_committed_bulk(
+	struct xfs_ail		*ailp,
+	struct xfs_log_vec	*log_vector,
+	xfs_lsn_t		commit_lsn,
+	int			aborted)
+{
+#define LOG_ITEM_BATCH_SIZE	32
+	struct xfs_log_item	*log_items[LOG_ITEM_BATCH_SIZE];
+	struct xfs_log_vec	*lv;
+	int			i = 0;
+
+	/* unpin all the log items */
+	for (lv = log_vector; lv; lv = lv->lv_next ) {
+		struct xfs_log_item	*lip = lv->lv_item;
+		xfs_lsn_t		item_lsn;
+
+		if (aborted)
+			lip->li_flags |= XFS_LI_ABORTED;
+		item_lsn = IOP_COMMITTED(lip, commit_lsn);
+
+		/* item_lsn of -1 means the item was freed */
+		if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0)
+			continue;
+
+		if (item_lsn != commit_lsn) {
+
+			/*
+			 * Not a bulk update option due to unusual item_lsn.
+			 * Push into AIL immediately, rechecking the lsn once
+			 * we have the ail lock. Then unpin the item.
+			 */
+			spin_lock(&ailp->xa_lock);
+			if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0)
+				xfs_trans_ail_update(ailp, lip, item_lsn);
+			else
+				spin_unlock(&ailp->xa_lock);
+			IOP_UNPIN(lip, 0);
+			continue;
+		}
+
+		/* Item is a candidate for bulk AIL insert.  */
+		log_items[i++] = lv->lv_item;
+		if (i >= LOG_ITEM_BATCH_SIZE) {
+			xfs_log_item_batch_insert(ailp, log_items,
+					LOG_ITEM_BATCH_SIZE, commit_lsn);
+			i = 0;
+		}
+	}
+
+	/* make sure we insert the remainder! */
+	if (i)
+		xfs_log_item_batch_insert(ailp, log_items, i, commit_lsn);
+}
+
 /*
  * Called from the trans_commit code when we notice that
  * the filesystem is in the middle of a forced shutdown.
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index 645928c..fe991a7 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -29,6 +29,7 @@
 #include "xfs_error.h"
 
 STATIC void xfs_ail_insert(struct xfs_ail *, xfs_log_item_t *);
+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 *);
@@ -502,6 +503,79 @@ xfs_trans_ail_update(
 }	/* xfs_trans_update_ail */
 
 /*
+ * xfs_trans_ail_update - bulk AIL insertion operation.
+ *
+ * @xfs_trans_ail_update takes an array of log items that all need to be
+ * positioned at the same LSN in the AIL. If an item is not in the AIL, it will
+ * be added.  Otherwise, it will be repositioned  by removing it and re-adding
+ * it to the AIL. If we move the first item in the AIL, update the log tail to
+ * match the new minimum LSN in the AIL.
+ *
+ * This function takes the AIL lock once to execute the update operations on
+ * all the items in the array, and as such should not be called with the AIL
+ * lock held. As a result, once we have the AIL lock, we need to check each log
+ * item LSN to confirm it needs to be moved forward in the AIL.
+ *
+ * To optimise the insert operation, we delete all the items from the AIL in
+ * the first pass, moving them into a temporary list, then splice the temporary
+ * list into the correct position in the AIL. This avoids needing to do an
+ * insert operation on every item.
+ *
+ * This function must be called with the AIL lock held.  The lock is dropped
+ * before returning.
+ */
+void
+xfs_trans_ail_update_bulk(
+	struct xfs_ail		*ailp,
+	struct xfs_log_item	**log_items,
+	int			nr_items,
+	xfs_lsn_t		lsn) __releases(ailp->xa_lock)
+{
+	xfs_log_item_t		*mlip;
+	xfs_lsn_t		tail_lsn;
+	int			mlip_changed = 0;
+	int			i;
+	LIST_HEAD(tmp);
+
+	mlip = xfs_ail_min(ailp);
+
+	for (i = 0; i < nr_items; i++) {
+		struct xfs_log_item *lip = log_items[i];
+		if (lip->li_flags & XFS_LI_IN_AIL) {
+			/* check if we really need to move the item */
+			if (XFS_LSN_CMP(lsn, lip->li_lsn) <= 0)
+				continue;
+
+			xfs_ail_delete(ailp, lip);
+			if (mlip == lip)
+				mlip_changed = 1;
+		} else {
+			lip->li_flags |= XFS_LI_IN_AIL;
+		}
+		lip->li_lsn = lsn;
+		list_add(&lip->li_ail, &tmp);
+	}
+
+	xfs_ail_splice(ailp, &tmp, lsn);
+
+	if (!mlip_changed) {
+		spin_unlock(&ailp->xa_lock);
+		return;
+	}
+
+	/*
+	 * 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.
+	 */
+	mlip = xfs_ail_min(ailp);
+	tail_lsn = mlip->li_lsn;
+	spin_unlock(&ailp->xa_lock);
+	xfs_log_move_tail(ailp->xa_mount, tail_lsn);
+}
+
+/*
  * Delete the given item from the AIL.  It must already be in
  * the AIL.
  *
@@ -642,8 +716,8 @@ xfs_ail_insert(
 			break;
 	}
 
-	ASSERT((&next_lip->li_ail == &ailp->xa_ail) ||
-	       (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0));
+	ASSERT(&next_lip->li_ail == &ailp->xa_ail ||
+	       XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0);
 
 	list_add(&lip->li_ail, &next_lip->li_ail);
 
@@ -652,6 +726,37 @@ xfs_ail_insert(
 }
 
 /*
+ * 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);
+	return;
+}
+
+/*
  * Delete the given item from the AIL.  Return a pointer to the item.
  */
 STATIC void
diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
index 62da86c..e039729 100644
--- a/fs/xfs/xfs_trans_priv.h
+++ b/fs/xfs/xfs_trans_priv.h
@@ -22,15 +22,17 @@ struct xfs_log_item;
 struct xfs_log_item_desc;
 struct xfs_mount;
 struct xfs_trans;
+struct xfs_ail;
+struct xfs_log_vec;
 
 void	xfs_trans_add_item(struct xfs_trans *, struct xfs_log_item *);
 void	xfs_trans_del_item(struct xfs_log_item *);
 void	xfs_trans_free_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn,
 				int flags);
-void	xfs_trans_item_committed(struct xfs_log_item *lip,
-				xfs_lsn_t commit_lsn, int aborted);
 void	xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp);
 
+void	xfs_trans_committed_bulk(struct xfs_ail *ailp, struct xfs_log_vec *lv,
+				xfs_lsn_t commit_lsn, int aborted);
 /*
  * AIL traversal cursor.
  *
@@ -76,6 +78,10 @@ struct xfs_ail {
 void			xfs_trans_ail_update(struct xfs_ail *ailp,
 					struct xfs_log_item *lip, xfs_lsn_t lsn)
 					__releases(ailp->xa_lock);
+void			 xfs_trans_ail_update_bulk(struct xfs_ail *ailp,
+					struct xfs_log_item **log_items,
+					int nr_items, xfs_lsn_t lsn)
+					__releases(ailp->xa_lock);
 void			xfs_trans_ail_delete(struct xfs_ail *ailp,
 					struct xfs_log_item *lip)
 					__releases(ailp->xa_lock);