1 files changed, 4 insertions, 6 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f770e8b5cb86..23c49ab2de4c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -303,7 +303,7 @@ static int csum_tree_block(struct btrfs_fs_info *fs_info,
                 offset += cur_len;
         }
         if (csum_size > sizeof(inline_result)) {
-                result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
+                result = kzalloc(csum_size, GFP_NOFS);
                 if (!result)
                         return 1;
         } else {
@@ -1724,12 +1724,11 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 {
         int err;
 
-        bdi->capabilities = BDI_CAP_MAP_COPY;
-        err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
+        err = bdi_setup_and_register(bdi, "btrfs");
         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;
@@ -2181,7 +2180,6 @@ static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info,
          */
         fs_info->btree_inode->i_size = OFFSET_MAX;
         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
-        fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
 
         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
@@ -2530,7 +2528,7 @@ int open_ctree(struct super_block *sb,
         fs_info->free_chunk_space = 0;
         fs_info->tree_mod_log = RB_ROOT;
         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
-        fs_info->avg_delayed_ref_runtime = div64_u64(NSEC_PER_SEC, 64);
+        fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
         /* readahead state */
         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
         spin_lock_init(&fs_info->reada_lock);