xfs: AIL should be log centric

The AIL operates purely on log items, so it is a log centric
subsystem. Divorce it from the xfs_mount and instead have it pass
around xlog pointers.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/xfs_trans.c

@@ -775,7 +775,7 @@ xfs_trans_committed_bulk(
 		 * object into the AIL as we are in a shutdown situation.
 		 */
 		if (aborted) {
-			ASSERT(xfs_is_shutdown(ailp->ail_mount));
+			ASSERT(xlog_is_shutdown(ailp->ail_log));
 			if (lip->li_ops->iop_unpin)
 				lip->li_ops->iop_unpin(lip, 1);
 			continue;

fs/xfs/xfs_trans_ail.c

@@ -398,7 +398,7 @@ xfsaild_push_item(
 	 * If log item pinning is enabled, skip the push and track the item as
 	 * pinned. This can help induce head-behind-tail conditions.
 	 */
-	if (XFS_TEST_ERROR(false, ailp->ail_mount, XFS_ERRTAG_LOG_ITEM_PIN))
+	if (XFS_TEST_ERROR(false, ailp->ail_log->l_mp, XFS_ERRTAG_LOG_ITEM_PIN))
 		return XFS_ITEM_PINNED;
 
 	/*
@@ -418,7 +418,7 @@ static long
 xfsaild_push(
 	struct xfs_ail		*ailp)
 {
-	xfs_mount_t		*mp = ailp->ail_mount;
+	struct xfs_mount	*mp = ailp->ail_log->l_mp;
 	struct xfs_ail_cursor	cur;
 	struct xfs_log_item	*lip;
 	xfs_lsn_t		lsn;
@@ -443,7 +443,7 @@ xfsaild_push(
 		ailp->ail_log_flush = 0;
 
 		XFS_STATS_INC(mp, xs_push_ail_flush);
-		xlog_cil_flush(mp->m_log);
+		xlog_cil_flush(ailp->ail_log);
 	}
 
 	spin_lock(&ailp->ail_lock);
@@ -632,7 +632,7 @@ xfsaild(
 			 * opportunity to release such buffers from the queue.
 			 */
 			ASSERT(list_empty(&ailp->ail_buf_list) ||
-			       xfs_is_shutdown(ailp->ail_mount));
+			       xlog_is_shutdown(ailp->ail_log));
 			xfs_buf_delwri_cancel(&ailp->ail_buf_list);
 			break;
 		}
@@ -695,7 +695,7 @@ xfs_ail_push(
 	struct xfs_log_item	*lip;
 
 	lip = xfs_ail_min(ailp);
-	if (!lip || xfs_is_shutdown(ailp->ail_mount) ||
+	if (!lip || xlog_is_shutdown(ailp->ail_log) ||
 	    XFS_LSN_CMP(threshold_lsn, ailp->ail_target) <= 0)
 		return;
 
@@ -751,21 +751,21 @@ xfs_ail_update_finish(
 	struct xfs_ail		*ailp,
 	xfs_lsn_t		old_lsn) __releases(ailp->ail_lock)
 {
-	struct xfs_mount	*mp = ailp->ail_mount;
+	struct xlog		*log = ailp->ail_log;
 
 	/* if the tail lsn hasn't changed, don't do updates or wakeups. */
 	if (!old_lsn || old_lsn == __xfs_ail_min_lsn(ailp)) {
 		spin_unlock(&ailp->ail_lock);
 		return;
 	}
 
-	if (!xfs_is_shutdown(mp))
-		xlog_assign_tail_lsn_locked(mp);
+	if (!xlog_is_shutdown(log))
+		xlog_assign_tail_lsn_locked(log->l_mp);
 
 	if (list_empty(&ailp->ail_head))
 		wake_up_all(&ailp->ail_empty);
 	spin_unlock(&ailp->ail_lock);
-	xfs_log_space_wake(mp);
+	xfs_log_space_wake(log->l_mp);
 }
 
 /*
@@ -873,13 +873,13 @@ xfs_trans_ail_delete(
 	int			shutdown_type)
 {
 	struct xfs_ail		*ailp = lip->li_ailp;
-	struct xfs_mount	*mp = ailp->ail_mount;
+	struct xfs_mount	*mp = ailp->ail_log->l_mp;
 	xfs_lsn_t		tail_lsn;
 
 	spin_lock(&ailp->ail_lock);
 	if (!test_bit(XFS_LI_IN_AIL, &lip->li_flags)) {
 		spin_unlock(&ailp->ail_lock);
-		if (shutdown_type && !xfs_is_shutdown(mp)) {
+		if (shutdown_type && !xlog_is_shutdown(ailp->ail_log)) {
 			xfs_alert_tag(mp, XFS_PTAG_AILDELETE,
 	"%s: attempting to delete a log item that is not in the AIL",
 					__func__);
@@ -904,15 +904,15 @@ xfs_trans_ail_init(
 	if (!ailp)
 		return -ENOMEM;
 
-	ailp->ail_mount = mp;
+	ailp->ail_log = mp->m_log;
 	INIT_LIST_HEAD(&ailp->ail_head);
 	INIT_LIST_HEAD(&ailp->ail_cursors);
 	spin_lock_init(&ailp->ail_lock);
 	INIT_LIST_HEAD(&ailp->ail_buf_list);
 	init_waitqueue_head(&ailp->ail_empty);
 
 	ailp->ail_task = kthread_run(xfsaild, ailp, "xfsaild/%s",
-			ailp->ail_mount->m_super->s_id);
+				mp->m_super->s_id);
 	if (IS_ERR(ailp->ail_task))
 		goto out_free_ailp;
 

fs/xfs/xfs_trans_priv.h

@@ -6,6 +6,7 @@
 #ifndef __XFS_TRANS_PRIV_H__
 #define	__XFS_TRANS_PRIV_H__
 
+struct xlog;
 struct xfs_log_item;
 struct xfs_mount;
 struct xfs_trans;
@@ -50,7 +51,7 @@ struct xfs_ail_cursor {
  * Eventually we need to drive the locking in here as well.
  */
 struct xfs_ail {
-	struct xfs_mount	*ail_mount;
+	struct xlog		*ail_log;
 	struct task_struct	*ail_task;
 	struct list_head	ail_head;
 	xfs_lsn_t		ail_target;