1 files changed, 21 insertions, 5 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3cf4cfa575c8..e83be2e4602c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -42,6 +42,8 @@
 static struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
 
+static atomic_t btrfs_bdi_num = ATOMIC_INIT(0);
+
 /*
  * end_io_wq structs are used to do processing in task context when an IO is
  * complete.  This is used during reads to verify checksums, and it is used
@@ -1342,12 +1344,25 @@ static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
         free_extent_map(em);
 }
 
+/*
+ * If this fails, caller must call bdi_destroy() to get rid of the
+ * bdi again.
+ */
 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 {
-        bdi_init(bdi);
+        int err;
+
+        bdi->capabilities = BDI_CAP_MAP_COPY;
+        err = bdi_init(bdi);
+        if (err)
+                return err;
+
+        err = bdi_register(bdi, NULL, "btrfs-%d",
+                                atomic_inc_return(&btrfs_bdi_num));
+        if (err)
+                return err;
+
         bdi->ra_pages   = default_backing_dev_info.ra_pages;
-        bdi->state              = 0;
-        bdi->capabilities       = default_backing_dev_info.capabilities;
         bdi->unplug_io_fn       = btrfs_unplug_io_fn;
         bdi->unplug_io_data     = info;
         bdi->congested_fn       = btrfs_congested_fn;
@@ -1569,7 +1584,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         fs_info->sb = sb;
         fs_info->max_extent = (u64)-1;
         fs_info->max_inline = 8192 * 1024;
-        setup_bdi(fs_info, &fs_info->bdi);
+        if (setup_bdi(fs_info, &fs_info->bdi))
+                goto fail_bdi;
         fs_info->btree_inode = new_inode(sb);
         fs_info->btree_inode->i_ino = 1;
         fs_info->btree_inode->i_nlink = 1;
@@ -1957,8 +1973,8 @@ fail_iput:
 
         btrfs_close_devices(fs_info->fs_devices);
         btrfs_mapping_tree_free(&fs_info->mapping_tree);
+fail_bdi:
         bdi_destroy(&fs_info->bdi);
-
 fail:
         kfree(extent_root);
         kfree(tree_root);