fsnotify: Move mark list head from object into dedicated structure

[sfrench/cifs-2.6.git] / fs / notify / fsnotify.c

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index b41515d3f0815246185b264532d71cc43824ef9a..eae621a18ac9edfd951a815f2f0900d7cbc53175 100644 (file)
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -193,6 +193,7 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
        struct hlist_node *inode_node = NULL, *vfsmount_node = NULL;
        struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;
        struct fsnotify_group *inode_group, *vfsmount_group;
+       struct fsnotify_mark_connector *inode_conn, *vfsmount_conn;
        struct mount *mnt;
        int idx, ret = 0;
        /* global tests shouldn't care about events on child only the specific event */
@@ -210,8 +211,8 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
         * SRCU because we have no references to any objects and do not
         * need SRCU to keep them "alive".
         */
-       if (hlist_empty(&to_tell->i_fsnotify_marks) &&
-           (!mnt || hlist_empty(&mnt->mnt_fsnotify_marks)))
+       if (!to_tell->i_fsnotify_marks &&
+           (!mnt || !mnt->mnt_fsnotify_marks))
                return 0;
        /*
         * if this is a modify event we may need to clear the ignored masks
@@ -226,16 +227,24 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
        idx = srcu_read_lock(&fsnotify_mark_srcu);
 
        if ((mask & FS_MODIFY) ||
-           (test_mask & to_tell->i_fsnotify_mask))
-               inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
-                                             &fsnotify_mark_srcu);
+           (test_mask & to_tell->i_fsnotify_mask)) {
+               inode_conn = lockless_dereference(to_tell->i_fsnotify_marks);
+               if (inode_conn)
+                       inode_node = srcu_dereference(inode_conn->list.first,
+                                                     &fsnotify_mark_srcu);
+       }
 
        if (mnt && ((mask & FS_MODIFY) ||
                    (test_mask & mnt->mnt_fsnotify_mask))) {
-               vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first,
-                                                &fsnotify_mark_srcu);
-               inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
-                                             &fsnotify_mark_srcu);
+               inode_conn = lockless_dereference(to_tell->i_fsnotify_marks);
+               if (inode_conn)
+                       inode_node = srcu_dereference(inode_conn->list.first,
+                                                     &fsnotify_mark_srcu);
+               vfsmount_conn = lockless_dereference(mnt->mnt_fsnotify_marks);
+               if (vfsmount_conn)
+                       vfsmount_node = srcu_dereference(
+                                               vfsmount_conn->list.first,
+                                               &fsnotify_mark_srcu);
        }
 
        /*
@@ -293,6 +302,8 @@ out:
 }
 EXPORT_SYMBOL_GPL(fsnotify);
 
+extern struct kmem_cache *fsnotify_mark_connector_cachep;
+
 static __init int fsnotify_init(void)
 {
        int ret;
@@ -303,6 +314,9 @@ static __init int fsnotify_init(void)
        if (ret)
                panic("initializing fsnotify_mark_srcu");
 
+       fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector,
+                                                   SLAB_PANIC);
+
        return 0;
 }
 core_initcall(fsnotify_init);