GFS2: Use generic list_lru for quota

By using the generic list_lru code, we can now separate the
per sb quota list locking from the lru locking. The lru
lock is made into the inner-most lock.

As a result of this new lock order, we may occasionally see
items on the per-sb quota list which are "dead" so that the
two places where we traverse that list are updated to take
account of that.

As a result of this patch, the gfs2 quota shrinker is now
NUMA zone aware, and we are also laying the foundations for
further improvments in due course.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Abhijith Das <adas@redhat.com>
Tested-by: Abhijith Das <adas@redhat.com>
Cc: Dave Chinner <dchinner@redhat.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index 351586e24e30..0650db2541ef 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -31,12 +31,6 @@
 
 struct workqueue_struct *gfs2_control_wq;
 
-static struct shrinker qd_shrinker = {
-        .count_objects = gfs2_qd_shrink_count,
-        .scan_objects = gfs2_qd_shrink_scan,
-        .seeks = DEFAULT_SEEKS,
-};
-
 static void gfs2_init_inode_once(void *foo)
 {
         struct gfs2_inode *ip = foo;
@@ -87,6 +81,10 @@ static int __init init_gfs2_fs(void)
         if (error)
                 return error;
 
+        error = list_lru_init(&gfs2_qd_lru);
+        if (error)
+                goto fail_lru;
+
         error = gfs2_glock_init();
         if (error)
                 goto fail;
@@ -139,7 +137,7 @@ static int __init init_gfs2_fs(void)
         if (!gfs2_rsrv_cachep)
                 goto fail;
 
-        register_shrinker(&qd_shrinker);
+        register_shrinker(&gfs2_qd_shrinker);
 
         error = register_filesystem(&gfs2_fs_type);
         if (error)
@@ -179,7 +177,9 @@ fail_wq:
 fail_unregister:
         unregister_filesystem(&gfs2_fs_type);
 fail:
-        unregister_shrinker(&qd_shrinker);
+        list_lru_destroy(&gfs2_qd_lru);
+fail_lru:
+        unregister_shrinker(&gfs2_qd_shrinker);
         gfs2_glock_exit();
 
         if (gfs2_rsrv_cachep)
@@ -214,13 +214,14 @@ fail:
 
 static void __exit exit_gfs2_fs(void)
 {
-        unregister_shrinker(&qd_shrinker);
+        unregister_shrinker(&gfs2_qd_shrinker);
         gfs2_glock_exit();
         gfs2_unregister_debugfs();
         unregister_filesystem(&gfs2_fs_type);
         unregister_filesystem(&gfs2meta_fs_type);
         destroy_workqueue(gfs_recovery_wq);
         destroy_workqueue(gfs2_control_wq);
+        list_lru_destroy(&gfs2_qd_lru);
 
         rcu_barrier();