1 files changed, 53 insertions, 18 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 790f4b61a3d7..a4f531047c4a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -41,6 +41,7 @@
 
 static struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
+static void free_fs_root(struct btrfs_root *root);
 
 static atomic_t btrfs_bdi_num = ATOMIC_INIT(0);
 
@@ -951,14 +952,16 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
                      root, fs_info, objectid);
         ret = btrfs_find_last_root(tree_root, objectid,
                                    &root->root_item, &root->root_key);
+        if (ret > 0)
+                return -ENOENT;
         BUG_ON(ret);
 
         generation = btrfs_root_generation(&root->root_item);
         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
                                      blocksize, generation);
-        root->commit_root = btrfs_root_node(root);
         BUG_ON(!root->node);
+        root->commit_root = btrfs_root_node(root);
         return 0;
 }
 
@@ -1176,39 +1179,66 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
                 return fs_info->dev_root;
         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
                 return fs_info->csum_root;
-
+again:
+        spin_lock(&fs_info->fs_roots_radix_lock);
         root = radix_tree_lookup(&fs_info->fs_roots_radix,
                                  (unsigned long)location->objectid);
+        spin_unlock(&fs_info->fs_roots_radix_lock);
         if (root)
                 return root;
 
+        ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
+        if (ret == 0)
+                ret = -ENOENT;
+        if (ret < 0)
+                return ERR_PTR(ret);
+
         root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
         if (IS_ERR(root))
                 return root;
 
+        WARN_ON(btrfs_root_refs(&root->root_item) == 0);
         set_anon_super(&root->anon_super, NULL);
 
+        ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
+        if (ret)
+                goto fail;
+
+        spin_lock(&fs_info->fs_roots_radix_lock);
         ret = radix_tree_insert(&fs_info->fs_roots_radix,
                                 (unsigned long)root->root_key.objectid,
                                 root);
+        if (ret == 0)
+                root->in_radix = 1;
+        spin_unlock(&fs_info->fs_roots_radix_lock);
+        radix_tree_preload_end();
         if (ret) {
-                free_extent_buffer(root->node);
-                kfree(root);
-                return ERR_PTR(ret);
+                if (ret == -EEXIST) {
+                        free_fs_root(root);
+                        goto again;
+                }
+                goto fail;
         }
-        if (!(fs_info->sb->s_flags & MS_RDONLY)) {
-                ret = btrfs_find_dead_roots(fs_info->tree_root,
-                                            root->root_key.objectid);
-                BUG_ON(ret);
+
+        ret = btrfs_find_dead_roots(fs_info->tree_root,
+                                    root->root_key.objectid);
+        WARN_ON(ret);
+
+        if (!(fs_info->sb->s_flags & MS_RDONLY))
                 btrfs_orphan_cleanup(root);
-        }
+
         return root;
+fail:
+        free_fs_root(root);
+        return ERR_PTR(ret);
 }
 
 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                                       struct btrfs_key *location,
                                       const char *name, int namelen)
 {
+        return btrfs_read_fs_root_no_name(fs_info, location);
+#if 0
         struct btrfs_root *root;
         int ret;
 
@@ -1225,7 +1255,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                 kfree(root);
                 return ERR_PTR(ret);
         }
-#if 0
+
         ret = btrfs_sysfs_add_root(root);
         if (ret) {
                 free_extent_buffer(root->node);
@@ -1233,9 +1263,9 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                 kfree(root);
                 return ERR_PTR(ret);
         }
-#endif
         root->in_sysfs = 1;
         return root;
+#endif
 }
 
 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
@@ -2229,20 +2259,25 @@ int write_ctree_super(struct btrfs_trans_handle *trans,
 
 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 {
-        WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
+        spin_lock(&fs_info->fs_roots_radix_lock);
         radix_tree_delete(&fs_info->fs_roots_radix,
                           (unsigned long)root->root_key.objectid);
+        spin_unlock(&fs_info->fs_roots_radix_lock);
+        free_fs_root(root);
+        return 0;
+}
+
+static void free_fs_root(struct btrfs_root *root)
+{
+        WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
         if (root->anon_super.s_dev) {
                 down_write(&root->anon_super.s_umount);
                 kill_anon_super(&root->anon_super);
         }
-        if (root->node)
-                free_extent_buffer(root->node);
-        if (root->commit_root)
-                free_extent_buffer(root->commit_root);
+        free_extent_buffer(root->node);
+        free_extent_buffer(root->commit_root);
         kfree(root->name);
         kfree(root);
-        return 0;
 }
 
 static int del_fs_roots(struct btrfs_fs_info *fs_info)