Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: revert to using a kthread for AIL pushing
  xfs: force the log if we encounter pinned buffers in .iop_pushbuf
  xfs: do not update xa_last_pushed_lsn for locked items

fs/xfs/xfs_buf_item.c

@@ -629,7 +629,7 @@ xfs_buf_item_push(
  * the xfsbufd to get this buffer written. We have to unlock the buffer
  * to allow the xfsbufd to write it, too.
  */
-STATIC void
+STATIC bool
 xfs_buf_item_pushbuf(
 	struct xfs_log_item	*lip)
 {
@@ -643,6 +643,7 @@ xfs_buf_item_pushbuf(
 
 	xfs_buf_delwri_promote(bp);
 	xfs_buf_relse(bp);
+	return true;
 }
 
 STATIC void

fs/xfs/xfs_dquot_item.c

@@ -183,13 +183,14 @@ xfs_qm_dqunpin_wait(
  * search the buffer cache can be a time consuming thing, and AIL lock is a
  * spinlock.
  */
-STATIC void
+STATIC bool
 xfs_qm_dquot_logitem_pushbuf(
 	struct xfs_log_item	*lip)
 {
 	struct xfs_dq_logitem	*qlip = DQUOT_ITEM(lip);
 	struct xfs_dquot	*dqp = qlip->qli_dquot;
 	struct xfs_buf		*bp;
+	bool			ret = true;
 
 	ASSERT(XFS_DQ_IS_LOCKED(dqp));
 
@@ -201,17 +202,20 @@ xfs_qm_dquot_logitem_pushbuf(
 	if (completion_done(&dqp->q_flush) ||
 	    !(lip->li_flags & XFS_LI_IN_AIL)) {
 		xfs_dqunlock(dqp);
-		return;
+		return true;
 	}
 
 	bp = xfs_incore(dqp->q_mount->m_ddev_targp, qlip->qli_format.qlf_blkno,
 			dqp->q_mount->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);
 	xfs_dqunlock(dqp);
 	if (!bp)
-		return;
+		return true;
 	if (XFS_BUF_ISDELAYWRITE(bp))
 		xfs_buf_delwri_promote(bp);
+	if (xfs_buf_ispinned(bp))
+		ret = false;
 	xfs_buf_relse(bp);
+	return ret;
 }
 
 /*

fs/xfs/xfs_inode_item.c

@@ -708,13 +708,14 @@ xfs_inode_item_committed(
  * marked delayed write. If that's the case, we'll promote it and that will
  * allow the caller to write the buffer by triggering the xfsbufd to run.
  */
-STATIC void
+STATIC bool
 xfs_inode_item_pushbuf(
 	struct xfs_log_item	*lip)
 {
 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
 	struct xfs_inode	*ip = iip->ili_inode;
 	struct xfs_buf		*bp;
+	bool			ret = true;
 
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));
 
@@ -725,18 +726,21 @@ xfs_inode_item_pushbuf(
 	if (completion_done(&ip->i_flush) ||
 	    !(lip->li_flags & XFS_LI_IN_AIL)) {
 		xfs_iunlock(ip, XFS_ILOCK_SHARED);
-		return;
+		return true;
 	}
 
 	bp = xfs_incore(ip->i_mount->m_ddev_targp, iip->ili_format.ilf_blkno,
 			iip->ili_format.ilf_len, XBF_TRYLOCK);
 
 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
 	if (!bp)
-		return;
+		return true;
 	if (XFS_BUF_ISDELAYWRITE(bp))
 		xfs_buf_delwri_promote(bp);
+	if (xfs_buf_ispinned(bp))
+		ret = false;
 	xfs_buf_relse(bp);
+	return ret;
 }
 
 /*

fs/xfs/xfs_linux.h

@@ -68,6 +68,8 @@
 #include <linux/ctype.h>
 #include <linux/writeback.h>
 #include <linux/capability.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
 #include <linux/list_sort.h>
 
 #include <asm/page.h>

fs/xfs/xfs_super.c

@@ -1652,24 +1652,13 @@ xfs_init_workqueues(void)
 	 */
 	xfs_syncd_wq = alloc_workqueue("xfssyncd", WQ_CPU_INTENSIVE, 8);
 	if (!xfs_syncd_wq)
-		goto out;
-
-	xfs_ail_wq = alloc_workqueue("xfsail", WQ_CPU_INTENSIVE, 8);
-	if (!xfs_ail_wq)
-		goto out_destroy_syncd;
-
+		return -ENOMEM;
 	return 0;
-
-out_destroy_syncd:
-	destroy_workqueue(xfs_syncd_wq);
-out:
-	return -ENOMEM;
 }
 
 STATIC void
 xfs_destroy_workqueues(void)
 {
-	destroy_workqueue(xfs_ail_wq);
 	destroy_workqueue(xfs_syncd_wq);
 }
 

fs/xfs/xfs_trans.h

@@ -350,7 +350,7 @@ typedef struct xfs_item_ops {
 	void (*iop_unlock)(xfs_log_item_t *);
 	xfs_lsn_t (*iop_committed)(xfs_log_item_t *, xfs_lsn_t);
 	void (*iop_push)(xfs_log_item_t *);
-	void (*iop_pushbuf)(xfs_log_item_t *);
+	bool (*iop_pushbuf)(xfs_log_item_t *);
 	void (*iop_committing)(xfs_log_item_t *, xfs_lsn_t);
 } xfs_item_ops_t;
 

fs/xfs/xfs_trans_ail.c

@@ -28,8 +28,6 @@
 #include "xfs_trans_priv.h"
 #include "xfs_error.h"
 
-struct workqueue_struct	*xfs_ail_wq;	/* AIL workqueue */
-
 #ifdef DEBUG
 /*
  * Check that the list is sorted as it should be.
@@ -356,16 +354,10 @@ xfs_ail_delete(
 	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.
- */
-STATIC void
-xfs_ail_worker(
-	struct work_struct	*work)
+static long
+xfsaild_push(
+	struct xfs_ail		*ailp)
 {
-	struct xfs_ail		*ailp = container_of(to_delayed_work(work),
-					struct xfs_ail, xa_work);
 	xfs_mount_t		*mp = ailp->xa_mount;
 	struct xfs_ail_cursor	cur;
 	xfs_log_item_t		*lip;
@@ -427,8 +419,13 @@ xfs_ail_worker(
 
 		case XFS_ITEM_PUSHBUF:
 			XFS_STATS_INC(xs_push_ail_pushbuf);
-			IOP_PUSHBUF(lip);
-			ailp->xa_last_pushed_lsn = lsn;
+
+			if (!IOP_PUSHBUF(lip)) {
+				stuck++;
+				flush_log = 1;
+			} else {
+				ailp->xa_last_pushed_lsn = lsn;
+			}
 			push_xfsbufd = 1;
 			break;
 
@@ -440,7 +437,6 @@ xfs_ail_worker(
 
 		case XFS_ITEM_LOCKED:
 			XFS_STATS_INC(xs_push_ail_locked);
-			ailp->xa_last_pushed_lsn = lsn;
 			stuck++;
 			break;
 
@@ -501,20 +497,6 @@ xfs_ail_worker(
 		/* We're past our target or empty, so idle */
 		ailp->xa_last_pushed_lsn = 0;
 
-		/*
-		 * We clear the XFS_AIL_PUSHING_BIT first before checking
-		 * whether the target has changed. If the target has changed,
-		 * this pushes the requeue race directly onto the result of the
-		 * atomic test/set bit, so we are guaranteed that either the
-		 * the pusher that changed the target or ourselves will requeue
-		 * the work (but not both).
-		 */
-		clear_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags);
-		smp_rmb();
-		if (XFS_LSN_CMP(ailp->xa_target, target) == 0 ||
-		    test_and_set_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags))
-			return;
-
 		tout = 50;
 	} else if (XFS_LSN_CMP(lsn, target) >= 0) {
 		/*
@@ -537,9 +519,30 @@ xfs_ail_worker(
 		tout = 20;
 	}
 
-	/* There is more to do, requeue us.  */
-	queue_delayed_work(xfs_syncd_wq, &ailp->xa_work,
-					msecs_to_jiffies(tout));
+	return tout;
+}
+
+static int
+xfsaild(
+	void		*data)
+{
+	struct xfs_ail	*ailp = data;
+	long		tout = 0;	/* milliseconds */
+
+	while (!kthread_should_stop()) {
+		if (tout && tout <= 20)
+			__set_current_state(TASK_KILLABLE);
+		else
+			__set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(tout ?
+				 msecs_to_jiffies(tout) : MAX_SCHEDULE_TIMEOUT);
+
+		try_to_freeze();
+
+		tout = xfsaild_push(ailp);
+	}
+
+	return 0;
 }
 
 /*
@@ -574,8 +577,9 @@ xfs_ail_push(
 	 */
 	smp_wmb();
 	xfs_trans_ail_copy_lsn(ailp, &ailp->xa_target, &threshold_lsn);
-	if (!test_and_set_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags))
-		queue_delayed_work(xfs_syncd_wq, &ailp->xa_work, 0);
+	smp_wmb();
+
+	wake_up_process(ailp->xa_task);
 }
 
 /*
@@ -813,9 +817,18 @@ xfs_trans_ail_init(
 	INIT_LIST_HEAD(&ailp->xa_ail);
 	INIT_LIST_HEAD(&ailp->xa_cursors);
 	spin_lock_init(&ailp->xa_lock);
-	INIT_DELAYED_WORK(&ailp->xa_work, xfs_ail_worker);
+
+	ailp->xa_task = kthread_run(xfsaild, ailp, "xfsaild/%s",
+			ailp->xa_mount->m_fsname);
+	if (IS_ERR(ailp->xa_task))
+		goto out_free_ailp;
+
 	mp->m_ail = ailp;
 	return 0;
+
+out_free_ailp:
+	kmem_free(ailp);
+	return ENOMEM;
 }
 
 void
@@ -824,6 +837,6 @@ xfs_trans_ail_destroy(
 {
 	struct xfs_ail	*ailp = mp->m_ail;
 
-	cancel_delayed_work_sync(&ailp->xa_work);
+	kthread_stop(ailp->xa_task);
 	kmem_free(ailp);
 }

fs/xfs/xfs_trans_priv.h

@@ -64,23 +64,17 @@ struct xfs_ail_cursor {
  */
 struct xfs_ail {
 	struct xfs_mount	*xa_mount;
+	struct task_struct	*xa_task;
 	struct list_head	xa_ail;
 	xfs_lsn_t		xa_target;
 	struct list_head	xa_cursors;
 	spinlock_t		xa_lock;
-	struct delayed_work	xa_work;
 	xfs_lsn_t		xa_last_pushed_lsn;
-	unsigned long		xa_flags;
 };
 
-#define XFS_AIL_PUSHING_BIT	0
-
 /*
  * From xfs_trans_ail.c
  */
-
-extern struct workqueue_struct	*xfs_ail_wq;	/* AIL workqueue */
-
 void	xfs_trans_ail_update_bulk(struct xfs_ail *ailp,
 				struct xfs_ail_cursor *cur,
 				struct xfs_log_item **log_items, int nr_items,