1 files changed, 43 insertions, 39 deletions

diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index 9c514483e59..cb0f3a84cc6 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -18,15 +18,16 @@
  */
 #include "xfs.h"
 #include "xfs_fs.h"
-#include "xfs_types.h"
-#include "xfs_log.h"
-#include "xfs_trans.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
 #include "xfs_sb.h"
 #include "xfs_ag.h"
 #include "xfs_mount.h"
+#include "xfs_trans.h"
 #include "xfs_trans_priv.h"
 #include "xfs_trace.h"
 #include "xfs_error.h"
+#include "xfs_log.h"
 
 #ifdef DEBUG
 /*
@@ -55,40 +56,12 @@ xfs_ail_check(
 		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.
- */
-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 last item in the AIL.  If the AIL is empty, then
  * return NULL.
  */
@@ -200,7 +173,6 @@ xfs_trans_ail_cursor_next(
  */
 void
 xfs_trans_ail_cursor_done(
-	struct xfs_ail		*ailp,
 	struct xfs_ail_cursor	*cur)
 {
 	cur->item = NULL;
@@ -383,13 +355,19 @@ xfsaild_push(
 	}
 
 	spin_lock(&ailp->xa_lock);
+
+	/* barrier matches the xa_target update in xfs_ail_push() */
+	smp_rmb();
+	target = ailp->xa_target;
+	ailp->xa_target_prev = target;
+
 	lip = xfs_trans_ail_cursor_first(ailp, &cur, ailp->xa_last_pushed_lsn);
 	if (!lip) {
 		/*
 		 * If the AIL is empty or our push has reached the end we are
 		 * done now.
 		 */
-		xfs_trans_ail_cursor_done(ailp, &cur);
+		xfs_trans_ail_cursor_done(&cur);
 		spin_unlock(&ailp->xa_lock);
 		goto out_done;
 	}
@@ -397,16 +375,15 @@ xfsaild_push(
 	XFS_STATS_INC(xs_push_ail);
 
 	lsn = lip->li_lsn;
-	target = ailp->xa_target;
 	while ((XFS_LSN_CMP(lip->li_lsn, target) <= 0)) {
 		int	lock_result;
 
 		/*
-		 * Note that IOP_PUSH may unlock and reacquire the AIL lock.  We
+		 * Note that iop_push may unlock and reacquire the AIL lock.  We
 		 * rely on the AIL cursor implementation to be able to deal with
 		 * the dropped lock.
 		 */
-		lock_result = IOP_PUSH(lip, &ailp->xa_buf_list);
+		lock_result = lip->li_ops->iop_push(lip, &ailp->xa_buf_list);
 		switch (lock_result) {
 		case XFS_ITEM_SUCCESS:
 			XFS_STATS_INC(xs_push_ail_success);
@@ -475,7 +452,7 @@ xfsaild_push(
 			break;
 		lsn = lip->li_lsn;
 	}
-	xfs_trans_ail_cursor_done(ailp, &cur);
+	xfs_trans_ail_cursor_done(&cur);
 	spin_unlock(&ailp->xa_lock);
 
 	if (xfs_buf_delwri_submit_nowait(&ailp->xa_buf_list))
@@ -527,8 +504,32 @@ xfsaild(
 			__set_current_state(TASK_KILLABLE);
 		else
 			__set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(tout ?
-				 msecs_to_jiffies(tout) : MAX_SCHEDULE_TIMEOUT);
+
+		spin_lock(&ailp->xa_lock);
+
+		/*
+		 * Idle if the AIL is empty and we are not racing with a target
+		 * update. We check the AIL after we set the task to a sleep
+		 * state to guarantee that we either catch an xa_target update
+		 * or that a wake_up resets the state to TASK_RUNNING.
+		 * Otherwise, we run the risk of sleeping indefinitely.
+		 *
+		 * The barrier matches the xa_target update in xfs_ail_push().
+		 */
+		smp_rmb();
+		if (!xfs_ail_min(ailp) &&
+		    ailp->xa_target == ailp->xa_target_prev) {
+			spin_unlock(&ailp->xa_lock);
+			schedule();
+			tout = 0;
+			continue;
+		}
+		spin_unlock(&ailp->xa_lock);
+
+		if (tout)
+			schedule_timeout(msecs_to_jiffies(tout));
+
+		__set_current_state(TASK_RUNNING);
 
 		try_to_freeze();
 
@@ -657,11 +658,13 @@ xfs_trans_ail_update_bulk(
 			if (XFS_LSN_CMP(lsn, lip->li_lsn) <= 0)
 				continue;
 
+			trace_xfs_ail_move(lip, lip->li_lsn, lsn);
 			xfs_ail_delete(ailp, lip);
 			if (mlip == lip)
 				mlip_changed = 1;
 		} else {
 			lip->li_flags |= XFS_LI_IN_AIL;
+			trace_xfs_ail_insert(lip, 0, lsn);
 		}
 		lip->li_lsn = lsn;
 		list_add(&lip->li_ail, &tmp);
@@ -730,6 +733,7 @@ xfs_trans_ail_delete_bulk(
 			return;
 		}
 
+		trace_xfs_ail_delete(lip, mlip->li_lsn, lip->li_lsn);
 		xfs_ail_delete(ailp, lip);
 		lip->li_flags &= ~XFS_LI_IN_AIL;
 		lip->li_lsn = 0;