mutex_lock(&raw_mutex);
        bdev = raw_devices[minor].binding;
-       if (--raw_devices[minor].inuse == 0) {
+       if (--raw_devices[minor].inuse == 0)
                /* Here  inode->i_mapping == bdev->bd_inode->i_mapping  */
                inode->i_mapping = &inode->i_data;
-               inode->i_mapping->backing_dev_info = &default_backing_dev_info;
-       }
        mutex_unlock(&raw_mutex);
 
        blkdev_put(bdev, filp->f_mode | FMODE_EXCL);
 
 
        inode->i_mapping->a_ops = &aio_ctx_aops;
        inode->i_mapping->private_data = ctx;
-       inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
        inode->i_size = PAGE_SIZE * nr_pages;
 
        path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this);
 
        spin_unlock(&inode->i_lock);
 }
 
-/*
- * Move the inode from its current bdi to a new bdi.  Make sure the inode
- * is clean before moving so that it doesn't linger on the old bdi.
- */
-static void bdev_inode_switch_bdi(struct inode *inode,
-                       struct backing_dev_info *dst)
-{
-       spin_lock(&inode->i_lock);
-       WARN_ON_ONCE(inode->i_state & I_DIRTY);
-       inode->i_data.backing_dev_info = dst;
-       spin_unlock(&inode->i_lock);
-}
-
 /* Kill _all_ buffers and pagecache , dirty or not.. */
 void kill_bdev(struct block_device *bdev)
 {
                inode->i_bdev = bdev;
                inode->i_data.a_ops = &def_blk_aops;
                mapping_set_gfp_mask(&inode->i_data, GFP_USER);
-               inode->i_data.backing_dev_info = &default_backing_dev_info;
                spin_lock(&bdev_lock);
                list_add(&bdev->bd_list, &all_bdevs);
                spin_unlock(&bdev_lock);
                bdev->bd_queue = disk->queue;
                bdev->bd_contains = bdev;
                if (!partno) {
-                       struct backing_dev_info *bdi;
-
                        ret = -ENXIO;
                        bdev->bd_part = disk_get_part(disk, partno);
                        if (!bdev->bd_part)
                                }
                        }
 
-                       if (!ret) {
+                       if (!ret)
                                bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
-                               bdi = blk_get_backing_dev_info(bdev);
-                               bdev_inode_switch_bdi(bdev->bd_inode, bdi);
-                       }
 
                        /*
                         * If the device is invalidated, rescan partition
                        if (ret)
                                goto out_clear;
                        bdev->bd_contains = whole;
-                       bdev_inode_switch_bdi(bdev->bd_inode,
-                               whole->bd_inode->i_data.backing_dev_info);
                        bdev->bd_part = disk_get_part(disk, partno);
                        if (!(disk->flags & GENHD_FL_UP) ||
                            !bdev->bd_part || !bdev->bd_part->nr_sects) {
        bdev->bd_disk = NULL;
        bdev->bd_part = NULL;
        bdev->bd_queue = NULL;
-       bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info);
        if (bdev != bdev->bd_contains)
                __blkdev_put(bdev->bd_contains, mode, 1);
        bdev->bd_contains = NULL;
                 * dirty data before.
                 */
                bdev_write_inode(bdev->bd_inode);
-               bdev_inode_switch_bdi(bdev->bd_inode,
-                                       &default_backing_dev_info);
        }
        if (bdev->bd_contains == bdev) {
                if (disk->fops->release)
 
         */
        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,
 
        switch (inode->i_mode & S_IFMT) {
        case S_IFREG:
                inode->i_mapping->a_ops = &btrfs_aops;
-               inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
                BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
                inode->i_fop = &btrfs_file_operations;
                inode->i_op = &btrfs_file_inode_operations;
        case S_IFLNK:
                inode->i_op = &btrfs_symlink_inode_operations;
                inode->i_mapping->a_ops = &btrfs_symlink_aops;
-               inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
                break;
        default:
                inode->i_op = &btrfs_special_inode_operations;
        inode->i_fop = &btrfs_file_operations;
        inode->i_op = &btrfs_file_inode_operations;
        inode->i_mapping->a_ops = &btrfs_aops;
-       inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
 
        err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
        if (err)
        inode->i_fop = &btrfs_file_operations;
        inode->i_op = &btrfs_file_inode_operations;
        inode->i_mapping->a_ops = &btrfs_aops;
-       inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
        BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 
        err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
 
        inode->i_op = &btrfs_symlink_inode_operations;
        inode->i_mapping->a_ops = &btrfs_symlink_aops;
-       inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
        inode_set_bytes(inode, name_len);
        btrfs_i_size_write(inode, name_len);
        err = btrfs_update_inode(trans, root, inode);
        inode->i_op = &btrfs_file_inode_operations;
 
        inode->i_mapping->a_ops = &btrfs_aops;
-       inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
        BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 
        ret = btrfs_init_inode_security(trans, inode, dir, NULL);
 
        }
 
        inode->i_mapping->a_ops = &ceph_aops;
-       inode->i_mapping->backing_dev_info =
-               &ceph_sb_to_client(inode->i_sb)->backing_dev_info;
 
        switch (inode->i_mode & S_IFMT) {
        case S_IFIFO:
 
                        inode->i_flags |= S_NOATIME | S_NOCMTIME;
                if (inode->i_state & I_NEW) {
                        inode->i_ino = hash;
-                       if (S_ISREG(inode->i_mode))
-                               inode->i_data.backing_dev_info = sb->s_bdi;
 #ifdef CONFIG_CIFS_FSCACHE
                        /* initialize per-inode cache cookie pointer */
                        CIFS_I(inode)->fscache = NULL;
 
        if (inode) {
                inode->i_ino = get_next_ino();
                inode->i_mapping->a_ops = &configfs_aops;
-               inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
                inode->i_op = &configfs_inode_operations;
 
                if (sd->s_iattr) {
 
        inode->i_ino = lower_inode->i_ino;
        inode->i_version++;
        inode->i_mapping->a_ops = &ecryptfs_aops;
-       inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
 
        if (S_ISLNK(inode->i_mode))
                inode->i_op = &ecryptfs_symlink_iops;
 
                memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
        }
 
-       inode->i_mapping->backing_dev_info = sb->s_bdi;
        if (S_ISREG(inode->i_mode)) {
                inode->i_op = &exofs_file_inode_operations;
                inode->i_fop = &exofs_file_operations;
 
        set_obj_2bcreated(oi);
 
-       inode->i_mapping->backing_dev_info = sb->s_bdi;
        inode_init_owner(inode, dir, mode);
        inode->i_ino = sbi->s_nextid++;
        inode->i_blkbits = EXOFS_BLKSHIFT;
 
                if (!fc->writeback_cache || !S_ISREG(attr->mode))
                        inode->i_flags |= S_NOCMTIME;
                inode->i_generation = generation;
-               inode->i_data.backing_dev_info = &fc->bdi;
                fuse_init_inode(inode, attr);
                unlock_new_inode(inode);
        } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 
                mapping->flags = 0;
                mapping_set_gfp_mask(mapping, GFP_NOFS);
                mapping->private_data = NULL;
-               mapping->backing_dev_info = s->s_bdi;
                mapping->writeback_index = 0;
        }
 
 
        mapping->flags = 0;
        mapping_set_gfp_mask(mapping, GFP_NOFS);
        mapping->private_data = NULL;
-       mapping->backing_dev_info = sb->s_bdi;
        mapping->writeback_index = 0;
 
        spin_lock_init(&sdp->sd_log_lock);
 
                lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
                                &hugetlbfs_i_mmap_rwsem_key);
                inode->i_mapping->a_ops = &hugetlbfs_aops;
-               inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
                inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
                inode->i_mapping->private_data = resv_map;
                info = HUGETLBFS_I(inode);
 
        atomic_set(&mapping->i_mmap_writable, 0);
        mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE);
        mapping->private_data = NULL;
-       mapping->backing_dev_info = &default_backing_dev_info;
        mapping->writeback_index = 0;
-
-       /*
-        * If the block_device provides a backing_dev_info for client
-        * inodes then use that.  Otherwise the inode share the bdev's
-        * backing_dev_info.
-        */
-       if (sb->s_bdev) {
-               struct backing_dev_info *bdi;
-
-               bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
-               mapping->backing_dev_info = bdi;
-       }
        inode->i_private = NULL;
        inode->i_mapping = mapping;
        INIT_HLIST_HEAD(&inode->i_dentry);      /* buggered by rcu freeing */
 
        kernfs_get(kn);
        inode->i_private = kn;
        inode->i_mapping->a_ops = &kernfs_aops;
-       inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
        inode->i_op = &kernfs_iops;
 
        set_default_inode_attr(inode, kn->mode);
 
        if (inode) {
                atomic_set(&NCP_FINFO(inode)->opened, info->opened);
 
-               inode->i_mapping->backing_dev_info = sb->s_bdi;
                inode->i_ino = info->ino;
                ncp_set_attr(inode, info);
                if (S_ISREG(inode->i_mode)) {
 
                if (S_ISREG(inode->i_mode)) {
                        inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
                        inode->i_data.a_ops = &nfs_file_aops;
-                       inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
                } else if (S_ISDIR(inode->i_mode)) {
                        inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
                        inode->i_fop = &nfs_dir_operations;
 
        inode->i_mode = S_IFREG;
        mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
        inode->i_mapping->a_ops = &empty_aops;
-       inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
 
        ii->i_flags = 0;
        nilfs_bmap_init_gc(ii->i_bmap);
 
 
        inode->i_mode = S_IFREG;
        mapping_set_gfp_mask(inode->i_mapping, gfp_mask);
-       inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
 
        inode->i_op = &def_mdt_iops;
        inode->i_fop = &def_mdt_fops;
                               struct nilfs_shadow_map *shadow)
 {
        struct nilfs_mdt_info *mi = NILFS_MDT(inode);
-       struct backing_dev_info *bdi = inode->i_sb->s_bdi;
 
        INIT_LIST_HEAD(&shadow->frozen_buffers);
        address_space_init_once(&shadow->frozen_data);
-       nilfs_mapping_init(&shadow->frozen_data, inode, bdi);
+       nilfs_mapping_init(&shadow->frozen_data, inode);
        address_space_init_once(&shadow->frozen_btnodes);
-       nilfs_mapping_init(&shadow->frozen_btnodes, inode, bdi);
+       nilfs_mapping_init(&shadow->frozen_btnodes, inode);
        mi->mi_shadow = shadow;
        return 0;
 }
 
        return nc;
 }
 
-void nilfs_mapping_init(struct address_space *mapping, struct inode *inode,
-                       struct backing_dev_info *bdi)
+void nilfs_mapping_init(struct address_space *mapping, struct inode *inode)
 {
        mapping->host = inode;
        mapping->flags = 0;
        mapping_set_gfp_mask(mapping, GFP_NOFS);
        mapping->private_data = NULL;
-       mapping->backing_dev_info = bdi;
        mapping->a_ops = &empty_aops;
 }
 
 
 void nilfs_copy_back_pages(struct address_space *, struct address_space *);
 void nilfs_clear_dirty_page(struct page *, bool);
 void nilfs_clear_dirty_pages(struct address_space *, bool);
-void nilfs_mapping_init(struct address_space *mapping, struct inode *inode,
-                       struct backing_dev_info *bdi);
+void nilfs_mapping_init(struct address_space *mapping, struct inode *inode);
 unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
 unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
                                            sector_t start_blk,
 
        ii->i_state = 0;
        ii->i_cno = 0;
        ii->vfs_inode.i_version = 1;
-       nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode, sb->s_bdi);
+       nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode);
        return &ii->vfs_inode;
 }
 
 
        if (inode) {
                inode->i_ino = get_next_ino();
                inode_init_owner(inode, NULL, mode);
-               inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
                inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
                inc_nlink(inode);
 
 
        inode->i_ino = get_next_ino();
        inode_init_owner(inode, parent, mode);
-       inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 
        ip = DLMFS_I(inode);
 
                inode->i_ino = get_next_ino();
                inode_init_owner(inode, dir, mode);
                inode->i_mapping->a_ops = &ramfs_aops;
-               inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
                mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
                mapping_set_unevictable(inode->i_mapping);
                inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 
        case ROMFH_REG:
                i->i_fop = &romfs_ro_fops;
                i->i_data.a_ops = &romfs_aops;
-               if (i->i_sb->s_mtd)
-                       i->i_data.backing_dev_info =
-                               i->i_sb->s_mtd->backing_dev_info;
                if (nextfh & ROMFH_EXEC)
                        mode |= S_IXUGO;
                break;
 
        inode->i_mtime = inode->i_atime = inode->i_ctime =
                         ubifs_current_time(inode);
        inode->i_mapping->nrpages = 0;
-       /* Disable readahead */
-       inode->i_mapping->backing_dev_info = &c->bdi;
 
        switch (mode & S_IFMT) {
        case S_IFREG:
 
        if (err)
                goto out_invalid;
 
-       /* Disable read-ahead */
-       inode->i_mapping->backing_dev_info = &c->bdi;
-
        switch (inode->i_mode & S_IFMT) {
        case S_IFREG:
                inode->i_mapping->a_ops = &ubifs_file_address_operations;
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
 
+struct backing_dev_info;
 struct export_operations;
 struct hd_geometry;
 struct iovec;
                                loff_t pos, unsigned len, unsigned copied,
                                struct page *page, void *fsdata);
 
-struct backing_dev_info;
 struct address_space {
        struct inode            *host;          /* owner: inode, block_device */
        struct radix_tree_root  page_tree;      /* radix tree of all pages */
        pgoff_t                 writeback_index;/* writeback starts here */
        const struct address_space_operations *a_ops;   /* methods */
        unsigned long           flags;          /* error bits/gfp mask */
-       struct backing_dev_info *backing_dev_info; /* device readahead, etc */
        spinlock_t              private_lock;   /* for use by the address_space */
        struct list_head        private_list;   /* ditto */
        void                    *private_data;  /* ditto */
 
        .name           = "noop",
        .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
 };
-EXPORT_SYMBOL_GPL(noop_backing_dev_info);
 
 static struct class *bdi_class;
 
 
                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);
 
                .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,
        }
 };