1 files changed, 66 insertions, 6 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d75ca5cf59b1..f95cf5d4a69d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -46,6 +46,7 @@ struct btrfs_iget_args {
 static struct inode_operations btrfs_dir_inode_operations;
 static struct inode_operations btrfs_symlink_inode_operations;
 static struct inode_operations btrfs_dir_ro_inode_operations;
+static struct inode_operations btrfs_special_inode_operations;
 static struct inode_operations btrfs_file_inode_operations;
 static struct address_space_operations btrfs_aops;
 static struct address_space_operations btrfs_symlink_aops;
@@ -75,6 +76,7 @@ void btrfs_read_locked_inode(struct inode *inode)
         struct btrfs_root *root = BTRFS_I(inode)->root;
         struct btrfs_key location;
         u64 alloc_group_block;
+        u32 rdev;
         int ret;
 
         path = btrfs_alloc_path();
@@ -104,6 +106,8 @@ void btrfs_read_locked_inode(struct inode *inode)
         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
         inode->i_blocks = btrfs_inode_nblocks(inode_item);
         inode->i_generation = btrfs_inode_generation(inode_item);
+        inode->i_rdev = 0;
+        rdev = btrfs_inode_rdev(inode_item);
         alloc_group_block = btrfs_inode_block_group(inode_item);
         BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
                                                        alloc_group_block);
@@ -114,12 +118,6 @@ void btrfs_read_locked_inode(struct inode *inode)
         mutex_unlock(&root->fs_info->fs_mutex);
 
         switch (inode->i_mode & S_IFMT) {
-#if 0
-        default:
-                init_special_inode(inode, inode->i_mode,
-                                   btrfs_inode_rdev(inode_item));
-                break;
-#endif
         case S_IFREG:
                 inode->i_mapping->a_ops = &btrfs_aops;
                 inode->i_fop = &btrfs_file_operations;
@@ -136,6 +134,9 @@ void btrfs_read_locked_inode(struct inode *inode)
                 inode->i_op = &btrfs_symlink_inode_operations;
                 inode->i_mapping->a_ops = &btrfs_symlink_aops;
                 break;
+        default:
+                init_special_inode(inode, inode->i_mode, rdev);
+                break;
         }
         return;
 
@@ -162,6 +163,7 @@ static void fill_inode_item(struct btrfs_inode_item *item,
         btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
         btrfs_set_inode_nblocks(item, inode->i_blocks);
         btrfs_set_inode_generation(item, inode->i_generation);
+        btrfs_set_inode_rdev(item, inode->i_rdev);
         btrfs_set_inode_block_group(item,
                                     BTRFS_I(inode)->block_group->key.objectid);
 }
@@ -1070,6 +1072,58 @@ static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
         return err;
 }
 
+static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
+                        int mode, dev_t rdev)
+{
+        struct btrfs_trans_handle *trans;
+        struct btrfs_root *root = BTRFS_I(dir)->root;
+        struct inode *inode;
+        int err;
+        int drop_inode = 0;
+        u64 objectid;
+
+        if (!new_valid_dev(rdev))
+                return -EINVAL;
+
+        mutex_lock(&root->fs_info->fs_mutex);
+        trans = btrfs_start_transaction(root, 1);
+        btrfs_set_trans_block_group(trans, dir);
+
+        err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+        if (err) {
+                err = -ENOSPC;
+                goto out_unlock;
+        }
+
+        inode = btrfs_new_inode(trans, root, objectid,
+                                BTRFS_I(dir)->block_group, mode);
+        err = PTR_ERR(inode);
+        if (IS_ERR(inode))
+                goto out_unlock;
+
+        btrfs_set_trans_block_group(trans, inode);
+        err = btrfs_add_nondir(trans, dentry, inode);
+        if (err)
+                drop_inode = 1;
+        else {
+                inode->i_op = &btrfs_special_inode_operations;
+                init_special_inode(inode, inode->i_mode, rdev);
+        }
+        dir->i_sb->s_dirt = 1;
+        btrfs_update_inode_block_group(trans, inode);
+        btrfs_update_inode_block_group(trans, dir);
+out_unlock:
+        btrfs_end_transaction(trans, root);
+        mutex_unlock(&root->fs_info->fs_mutex);
+
+        if (drop_inode) {
+                inode_dec_link_count(inode);
+                iput(inode);
+        }
+        btrfs_btree_balance_dirty(root);
+        return err;
+}
+
 static int btrfs_create(struct inode *dir, struct dentry *dentry,
                         int mode, struct nameidata *nd)
 {
@@ -2526,6 +2580,7 @@ static struct inode_operations btrfs_dir_inode_operations = {
         .rename         = btrfs_rename,
         .symlink        = btrfs_symlink,
         .setattr        = btrfs_setattr,
+        .mknod          = btrfs_mknod,
 };
 
 static struct inode_operations btrfs_dir_ro_inode_operations = {
@@ -2562,6 +2617,11 @@ static struct inode_operations btrfs_file_inode_operations = {
         .setattr        = btrfs_setattr,
 };
 
+static struct inode_operations btrfs_special_inode_operations = {
+        .getattr        = btrfs_getattr,
+        .setattr        = btrfs_setattr,
+};
+
 static struct inode_operations btrfs_symlink_inode_operations = {
         .readlink       = generic_readlink,
         .follow_link    = page_follow_link_light,