Btrfs: Change the super to point to a tree of trees to enable persistent snapshots

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

1 files changed, 7 insertions, 8 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a6969538bca2..21f39b404697 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -82,7 +82,7 @@ int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf)
         u64 blocknr;
         int i;
 
-        if (root == root->extent_root)
+        if (!root->ref_cows)
                 return 0;
         if (btrfs_is_leaf(&buf->node))
                 return 0;
@@ -96,23 +96,22 @@ int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf)
 
 int btrfs_finish_extent_commit(struct btrfs_root *root)
 {
-        struct btrfs_root *extent_root = root->extent_root;
         unsigned long gang[8];
         int ret;
         int i;
 
         while(1) {
-                ret = radix_tree_gang_lookup(&extent_root->pinned_radix,
+                ret = radix_tree_gang_lookup(&root->pinned_radix,
                                                  (void **)gang, 0,
                                                  ARRAY_SIZE(gang));
                 if (!ret)
                         break;
                 for (i = 0; i < ret; i++) {
-                        radix_tree_delete(&extent_root->pinned_radix, gang[i]);
+                        radix_tree_delete(&root->pinned_radix, gang[i]);
                 }
         }
-        extent_root->last_insert.objectid = 0;
-        extent_root->last_insert.offset = 0;
+        root->last_insert.objectid = 0;
+        root->last_insert.offset = 0;
         return 0;
 }
 
@@ -173,7 +172,7 @@ static int __free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks)
         refs = btrfs_extent_refs(ei) - 1;
         btrfs_set_extent_refs(ei, refs);
         if (refs == 0) {
-                if (root == extent_root) {
+                if (!root->ref_cows) {
                         int err;
                         radix_tree_preload(GFP_KERNEL);
                         err = radix_tree_insert(&extent_root->pinned_radix,
@@ -513,7 +512,7 @@ static int walk_up_tree(struct btrfs_root *root, struct btrfs_path *path,
  */
 int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap)
 {
-        int ret = 0;;
+        int ret = 0;
         int wret;
         int level;
         struct btrfs_path path;