2 files changed, 27 insertions, 66 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 4c5deb6e9e31..0a00d7a2fc23 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -44,12 +44,7 @@
 
 static kmem_zone_t *xfs_buf_zone;
 STATIC int xfsbufd(void *);
-STATIC int xfsbufd_wakeup(struct shrinker *, int, gfp_t);
 STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int);
-static struct shrinker xfs_buf_shake = {
-        .shrink = xfsbufd_wakeup,
-        .seeks = DEFAULT_SEEKS,
-};
 
 static struct workqueue_struct *xfslogd_workqueue;
 struct workqueue_struct *xfsdatad_workqueue;
@@ -337,7 +332,6 @@ _xfs_buf_lookup_pages(
                                         __func__, gfp_mask);
 
                         XFS_STATS_INC(xb_page_retries);
-                        xfsbufd_wakeup(NULL, 0, gfp_mask);
                         congestion_wait(BLK_RW_ASYNC, HZ/50);
                         goto retry;
                 }
@@ -1461,28 +1455,23 @@ xfs_wait_buftarg(
         }
 }
 
-/*
- *      buftarg list for delwrite queue processing
- */
-static LIST_HEAD(xfs_buftarg_list);
-static DEFINE_SPINLOCK(xfs_buftarg_lock);
-
-STATIC void
-xfs_register_buftarg(
-        xfs_buftarg_t           *btp)
-{
-        spin_lock(&xfs_buftarg_lock);
-        list_add(&btp->bt_list, &xfs_buftarg_list);
-        spin_unlock(&xfs_buftarg_lock);
-}
-
-STATIC void
-xfs_unregister_buftarg(
-        xfs_buftarg_t           *btp)
+int
+xfs_buftarg_shrink(
+        struct shrinker         *shrink,
+        int                     nr_to_scan,
+        gfp_t                   mask)
 {
-        spin_lock(&xfs_buftarg_lock);
-        list_del(&btp->bt_list);
-        spin_unlock(&xfs_buftarg_lock);
+        struct xfs_buftarg      *btp = container_of(shrink,
+                                        struct xfs_buftarg, bt_shrinker);
+        if (nr_to_scan) {
+                if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags))
+                        return -1;
+                if (list_empty(&btp->bt_delwrite_queue))
+                        return -1;
+                set_bit(XBT_FORCE_FLUSH, &btp->bt_flags);
+                wake_up_process(btp->bt_task);
+        }
+        return list_empty(&btp->bt_delwrite_queue) ? -1 : 1;
 }
 
 void
@@ -1490,17 +1479,14 @@ xfs_free_buftarg(
         struct xfs_mount        *mp,
         struct xfs_buftarg      *btp)
 {
+        unregister_shrinker(&btp->bt_shrinker);
+
         xfs_flush_buftarg(btp, 1);
         if (mp->m_flags & XFS_MOUNT_BARRIER)
                 xfs_blkdev_issue_flush(btp);
         iput(btp->bt_mapping->host);
 
-        /* Unregister the buftarg first so that we don't get a
-         * wakeup finding a non-existent task
-         */
-        xfs_unregister_buftarg(btp);
         kthread_stop(btp->bt_task);
-
         kmem_free(btp);
 }
 
@@ -1597,20 +1583,13 @@ xfs_alloc_delwrite_queue(
         xfs_buftarg_t           *btp,
         const char              *fsname)
 {
-        int     error = 0;
-
-        INIT_LIST_HEAD(&btp->bt_list);
         INIT_LIST_HEAD(&btp->bt_delwrite_queue);
         spin_lock_init(&btp->bt_delwrite_lock);
         btp->bt_flags = 0;
         btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd/%s", fsname);
-        if (IS_ERR(btp->bt_task)) {
-                error = PTR_ERR(btp->bt_task);
-                goto out_error;
-        }
-        xfs_register_buftarg(btp);
-out_error:
-        return error;
+        if (IS_ERR(btp->bt_task))
+                return PTR_ERR(btp->bt_task);
+        return 0;
 }
 
 xfs_buftarg_t *
@@ -1633,6 +1612,9 @@ xfs_alloc_buftarg(
                 goto error;
         if (xfs_alloc_delwrite_queue(btp, fsname))
                 goto error;
+        btp->bt_shrinker.shrink = xfs_buftarg_shrink;
+        btp->bt_shrinker.seeks = DEFAULT_SEEKS;
+        register_shrinker(&btp->bt_shrinker);
         return btp;
 
 error:
@@ -1737,27 +1719,6 @@ xfs_buf_runall_queues(
         flush_workqueue(queue);
 }
 
-STATIC int
-xfsbufd_wakeup(
-        struct shrinker         *shrink,
-        int                     priority,
-        gfp_t                   mask)
-{
-        xfs_buftarg_t           *btp;
-
-        spin_lock(&xfs_buftarg_lock);
-        list_for_each_entry(btp, &xfs_buftarg_list, bt_list) {
-                if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags))
-                        continue;
-                if (list_empty(&btp->bt_delwrite_queue))
-                        continue;
-                set_bit(XBT_FORCE_FLUSH, &btp->bt_flags);
-                wake_up_process(btp->bt_task);
-        }
-        spin_unlock(&xfs_buftarg_lock);
-        return 0;
-}
-
 /*
  * Move as many buffers as specified to the supplied list
  * idicating if we skipped any buffers to prevent deadlocks.
@@ -1952,7 +1913,6 @@ xfs_buf_init(void)
         if (!xfsconvertd_workqueue)
                 goto out_destroy_xfsdatad_workqueue;
 
-        register_shrinker(&xfs_buf_shake);
         return 0;
 
  out_destroy_xfsdatad_workqueue:
@@ -1968,7 +1928,6 @@ xfs_buf_init(void)
 void
 xfs_buf_terminate(void)
 {
-        unregister_shrinker(&xfs_buf_shake);
         destroy_workqueue(xfsconvertd_workqueue);
         destroy_workqueue(xfsdatad_workqueue);
         destroy_workqueue(xfslogd_workqueue);
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index 383a3f37cf98..9344103e77d6 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -128,10 +128,12 @@ typedef struct xfs_buftarg {
 
         /* per device delwri queue */
         struct task_struct      *bt_task;
-        struct list_head        bt_list;
         struct list_head        bt_delwrite_queue;
         spinlock_t              bt_delwrite_lock;
         unsigned long           bt_flags;
+
+        /* LRU control structures */
+        struct shrinker         bt_shrinker;
 } xfs_buftarg_t;
 
 /*