Btrfs: groundwork for subvolume and snapshot roots

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

1 files changed, 22 insertions, 17 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 66d9fb2288c3..3c9236ca889c 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -436,7 +436,6 @@ int fixup_tree_root_location(struct btrfs_root *root,
 {
         struct btrfs_path *path;
         struct btrfs_root_item *ri;
-        int ret;
 
         if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
                 return 0;
@@ -447,22 +446,19 @@ int fixup_tree_root_location(struct btrfs_root *root,
         BUG_ON(!path);
         mutex_lock(&root->fs_info->fs_mutex);
 
-        ret = btrfs_lookup_inode(NULL, root, path, location, 0);
-        if (ret)
-                goto out;
-        ri = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-                          path->slots[0],
-                          struct btrfs_root_item);
+        *sub_root = btrfs_read_fs_root(root->fs_info, location);
+        if (IS_ERR(*sub_root))
+                return PTR_ERR(*sub_root);
+
+        ri = &(*sub_root)->root_item;
         location->objectid = btrfs_root_dirid(ri);
         location->flags = 0;
         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
         location->offset = 0;
-        /* FIXME properly select the root */
-        *sub_root = root->fs_info->fs_root;
-out:
+
         btrfs_free_path(path);
         mutex_unlock(&root->fs_info->fs_mutex);
-        return ret;
+        return 0;
 }
 
 
@@ -494,6 +490,15 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
                 if (!inode)
                         return ERR_PTR(-EACCES);
                 if (inode->i_state & I_NEW) {
+                        if (sub_root != root) {
+                                ret = radix_tree_insert(
+                                                &root->fs_info->fs_roots_radix,
+                                                (unsigned long)sub_root,
+                                                sub_root);
+printk("adding new root for inode %lu\n", inode->i_ino);
+                                igrab(inode);
+                                sub_root->inode = inode;
+                        }
                         BTRFS_I(inode)->root = sub_root;
                         memcpy(&BTRFS_I(inode)->location, &location,
                                sizeof(location));
@@ -605,7 +610,7 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
         struct inode * inode;
         struct dentry * root_dentry;
         struct btrfs_super_block *disk_super;
-        struct btrfs_root *root;
+        struct btrfs_root *tree_root;
         struct btrfs_inode *bi;
 
         sb->s_maxbytes = MAX_LFS_FILESIZE;
@@ -613,14 +618,14 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
         sb->s_op = &btrfs_super_ops;
         sb->s_time_gran = 1;
 
-        root = open_ctree(sb);
+        tree_root = open_ctree(sb);
 
-        if (!root) {
+        if (!tree_root) {
                 printk("btrfs: open_ctree failed\n");
                 return -EIO;
         }
-        sb->s_fs_info = root;
-        disk_super = root->fs_info->disk_super;
+        sb->s_fs_info = tree_root;
+        disk_super = tree_root->fs_info->disk_super;
         printk("read in super total blocks %Lu root %Lu\n",
                btrfs_super_total_blocks(disk_super),
                btrfs_super_root_dir(disk_super));
@@ -630,7 +635,7 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
         bi->location.objectid = inode->i_ino;
         bi->location.offset = 0;
         bi->location.flags = 0;
-        bi->root = root->fs_info->tree_root;
+        bi->root = tree_root;
         btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
 
         if (!inode)