Btrfs: early support for multiple devices

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ff69162829b3..e09233262af6 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -378,6 +378,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
 {
         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
                                                  GFP_NOFS);
+        struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
+                                                 GFP_NOFS);
         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
                                                GFP_NOFS);
         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
@@ -392,6 +394,7 @@ struct btrfs_root *open_ctree(struct super_block *sb)
         fs_info->running_transaction = NULL;
         fs_info->tree_root = tree_root;
         fs_info->extent_root = extent_root;
+        fs_info->dev_root = dev_root;
         fs_info->sb = sb;
         fs_info->btree_inode = new_inode(sb);
         fs_info->btree_inode->i_ino = 1;
@@ -414,6 +417,9 @@ struct btrfs_root *open_ctree(struct super_block *sb)
         memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
         memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
 
+        __setup_root(sb->s_blocksize, dev_root,
+                     fs_info, BTRFS_DEV_TREE_OBJECTID);
+
         __setup_root(sb->s_blocksize, tree_root,
                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
         fs_info->sb_buffer = read_tree_block(tree_root,
@@ -427,6 +433,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
                 return NULL;
 
         fs_info->disk_super = disk_super;
+        dev_root->node = read_tree_block(tree_root,
+                                          btrfs_super_device_root(disk_super));
         tree_root->node = read_tree_block(tree_root,
                                           btrfs_super_root(disk_super));
         BUG_ON(!tree_root->node);
@@ -519,6 +527,9 @@ int close_ctree(struct btrfs_root *root)
         if (fs_info->extent_root->node)
                 btrfs_block_release(fs_info->extent_root,
                                     fs_info->extent_root->node);
+        if (fs_info->dev_root->node)
+                btrfs_block_release(fs_info->dev_root,
+                                    fs_info->dev_root->node);
         if (fs_info->tree_root->node)
                 btrfs_block_release(fs_info->tree_root,
                                     fs_info->tree_root->node);