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

8 files changed, 69 insertions, 62 deletions

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index cac2ecfa6746..ef43fce519a1 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/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
diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c
index 9e0e2fa3f2c8..bb3f71d236d2 100644
--- a/fs/xfs/xfs_dquot_item.c
+++ b/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;
 }
 
 /*
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 588406dc6a35..836ad80d4f2b 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/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));
 
@@ -725,7 +726,7 @@ 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,
@@ -733,10 +734,13 @@ xfs_inode_item_pushbuf(
 
         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;
 }
 
 /*
diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index 1e8a45e74c3e..828662f70d64 100644
--- a/fs/xfs/xfs_linux.h
+++ b/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>
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 2366c54cc4fa..5cf06b85fd9d 100644
--- a/fs/xfs/xfs_super.c
+++ b/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);
 }
 
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index 06a9759b6352..53597f4db9b5 100644
--- a/fs/xfs/xfs_trans.h
+++ b/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;
 
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index c15aa29fa169..3a1e7ca54c2d 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/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 @@ out_done:
                 /* 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 @@ out_done:
                 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);
 }
diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
index 212946b97239..22750b5e4a8f 100644
--- a/fs/xfs/xfs_trans_priv.h
+++ b/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,