6 files changed, 6 insertions, 22 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 1ec872e3a926..1afb18226da8 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1719,7 +1719,7 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
         if (err)
                 return err;
 
-        bdi->ra_pages   = default_backing_dev_info.ra_pages;
+        bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE;
         bdi->congested_fn       = btrfs_congested_fn;
         bdi->congested_data     = info;
         return 0;
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index e350cc1611e4..5ae62587a71d 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -899,7 +899,7 @@ static int ceph_register_bdi(struct super_block *sb,
                         >> PAGE_SHIFT;
         else
                 fsc->backing_dev_info.ra_pages =
-                        default_backing_dev_info.ra_pages;
+                        VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE;
 
         err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%ld",
                            atomic_long_inc_return(&bdi_seq));
diff --git a/fs/super.c b/fs/super.c
index eae088f6aaae..3b4dadafdd60 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -185,8 +185,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
         }
         init_waitqueue_head(&s->s_writers.wait);
         init_waitqueue_head(&s->s_writers.wait_unfrozen);
+        s->s_bdi = &noop_backing_dev_info;
         s->s_flags = flags;
-        s->s_bdi = &default_backing_dev_info;
         INIT_HLIST_NODE(&s->s_instances);
         INIT_HLIST_BL_HEAD(&s->s_anon);
         INIT_LIST_HEAD(&s->s_inodes);
@@ -863,10 +863,7 @@ EXPORT_SYMBOL(free_anon_bdev);
 
 int set_anon_super(struct super_block *s, void *data)
 {
-        int error = get_anon_bdev(&s->s_dev);
-        if (!error)
-                s->s_bdi = &noop_backing_dev_info;
-        return error;
+        return get_anon_bdev(&s->s_dev);
 }
 
 EXPORT_SYMBOL(set_anon_super);
@@ -1111,7 +1108,6 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
         sb = root->d_sb;
         BUG_ON(!sb);
         WARN_ON(!sb->s_bdi);
-        WARN_ON(sb->s_bdi == &default_backing_dev_info);
         sb->s_flags |= MS_BORN;
 
         error = security_sb_kern_mount(sb, flags, secdata);
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index ed59dee03a71..d94077fea1f8 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -241,7 +241,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
 #define BDI_CAP_NO_ACCT_AND_WRITEBACK \
         (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
 
-extern struct backing_dev_info default_backing_dev_info;
 extern struct backing_dev_info noop_backing_dev_info;
 
 int writeback_in_progress(struct backing_dev_info *bdi);
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 74f5207bd090..0e9310905413 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -156,10 +156,8 @@ DECLARE_EVENT_CLASS(writeback_work_class,
                 __field(int, reason)
         ),
         TP_fast_assign(
-                struct device *dev = bdi->dev;
-                if (!dev)
-                        dev = default_backing_dev_info.dev;
-                strncpy(__entry->name, dev_name(dev), 32);
+                strncpy(__entry->name,
+                        bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32);
                 __entry->nr_pages = work->nr_pages;
                 __entry->sb_dev = work->sb ? work->sb->s_dev : 0;
                 __entry->sync_mode = work->sync_mode;
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 1725adb242e0..7690ec77c722 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -14,12 +14,6 @@
 
 static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
 
-struct backing_dev_info default_backing_dev_info = {
-        .name           = "default",
-        .ra_pages       = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE,
-};
-EXPORT_SYMBOL_GPL(default_backing_dev_info);
-
 struct backing_dev_info noop_backing_dev_info = {
         .name           = "noop",
         .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
@@ -250,9 +244,6 @@ static int __init default_bdi_init(void)
         if (!bdi_wq)
                 return -ENOMEM;
 
-        err = bdi_init(&default_backing_dev_info);
-        if (!err)
-                bdi_register(&default_backing_dev_info, NULL, "default");
         err = bdi_init(&noop_backing_dev_info);
 
         return err;