fs: remove mapping->backing_dev_info

Now that we never use the backing_dev_info pointer in struct address_space
we can simply remove it and save 4 to 8 bytes in every inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 0 insertions, 3 deletions

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 16c68958aeda..52e0c7652448 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -24,7 +24,6 @@ struct backing_dev_info noop_backing_dev_info = {
         .name           = "noop",
         .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
 };
-EXPORT_SYMBOL_GPL(noop_backing_dev_info);
 
 static struct class *bdi_class;
 
diff --git a/mm/shmem.c b/mm/shmem.c
index 1b77eaf589fd..4c61d3d5bfb4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1410,7 +1410,6 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
                 inode->i_ino = get_next_ino();
                 inode_init_owner(inode, dir, mode);
                 inode->i_blocks = 0;
-                inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
                 inode->i_generation = get_seconds();
                 info = SHMEM_I(inode);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 1c137b69ecde..405923f77334 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -37,7 +37,6 @@ struct address_space swapper_spaces[MAX_SWAPFILES] = {
                 .page_tree      = RADIX_TREE_INIT(GFP_ATOMIC|__GFP_NOWARN),
                 .i_mmap_writable = ATOMIC_INIT(0),
                 .a_ops          = &swap_aops,
-                .backing_dev_info = &noop_backing_dev_info,
         }
 };