Btrfs: Fix super block updates during transaction commit

The super block written during commit was not consistent with the state of
the trees.  This change adds an in-memory copy of the super so that we can
make sure to write out consistent data during a commit.

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

1 files changed, 8 insertions, 8 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 8025e9f8ef1..7e550343aee 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -796,8 +796,8 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
 
         for (i = 0; i < extent_root->fs_info->extent_tree_insert_nr; i++) {
                 ins.objectid = extent_root->fs_info->extent_tree_insert[i];
-                super_blocks_used = btrfs_super_blocks_used(info->disk_super);
-                btrfs_set_super_blocks_used(info->disk_super,
+                super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
+                btrfs_set_super_blocks_used(&info->super_copy,
                                             super_blocks_used + 1);
                 ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
                                         sizeof(extent_item));
@@ -892,8 +892,8 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                         BUG_ON(ret);
                 }
 
-                super_blocks_used = btrfs_super_blocks_used(info->disk_super);
-                btrfs_set_super_blocks_used(info->disk_super,
+                super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
+                btrfs_set_super_blocks_used(&info->super_copy,
                                             super_blocks_used - num_blocks);
                 ret = btrfs_del_item(trans, extent_root, path);
                 if (ret) {
@@ -1032,7 +1032,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                 info->extent_tree_prealloc_nr = 0;
         }
         if (search_end == (u64)-1)
-                search_end = btrfs_super_total_blocks(info->disk_super);
+                search_end = btrfs_super_total_blocks(&info->super_copy);
         if (hint_block) {
                 block_group = btrfs_lookup_block_group(info, hint_block);
                 block_group = btrfs_find_block_group(root, block_group,
@@ -1361,8 +1361,8 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                 }
         }
 
-        super_blocks_used = btrfs_super_blocks_used(info->disk_super);
-        btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
+        super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
+        btrfs_set_super_blocks_used(&info->super_copy, super_blocks_used +
                                     num_blocks);
         ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
                                 sizeof(extent_item));
@@ -1737,7 +1737,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                                            BTRFS_BLOCK_GROUP_AVAIL);
                 }
                 if (key.objectid >=
-                    btrfs_super_total_blocks(info->disk_super))
+                    btrfs_super_total_blocks(&info->super_copy))
                         break;
         }