Btrfs: Support for online FS resize (grow and shrink)

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

1 files changed, 24 insertions, 8 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index eebb4fb65c61..de026d9d9b2b 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -471,13 +471,17 @@ insert:
         return root;
 }
 
-struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
-                                      struct btrfs_key *location,
-                                      const char *name, int namelen)
+struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
+                                              struct btrfs_key *location)
 {
         struct btrfs_root *root;
         int ret;
 
+        if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
+                return fs_info->tree_root;
+        if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
+                return fs_info->extent_root;
+
         root = radix_tree_lookup(&fs_info->fs_roots_radix,
                                  (unsigned long)location->objectid);
         if (root)
@@ -494,6 +498,23 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                 kfree(root);
                 return ERR_PTR(ret);
         }
+        ret = btrfs_find_dead_roots(fs_info->tree_root,
+                                    root->root_key.objectid, root);
+        BUG_ON(ret);
+
+        return root;
+}
+
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
+                                      struct btrfs_key *location,
+                                      const char *name, int namelen)
+{
+        struct btrfs_root *root;
+        int ret;
+
+        root = btrfs_read_fs_root_no_name(fs_info, location);
+        if (!root)
+                return NULL;
 
         ret = btrfs_set_root_name(root, name, namelen);
         if (ret) {
@@ -509,11 +530,6 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                 kfree(root);
                 return ERR_PTR(ret);
         }
-
-        ret = btrfs_find_dead_roots(fs_info->tree_root,
-                                    root->root_key.objectid, root);
-        BUG_ON(ret);
-
         return root;
 }
 #if 0