Btrfs: Add back file data checksumming

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

1 files changed, 9 insertions, 8 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 9a65e97a4e28..10a4c7408600 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -136,27 +136,27 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
                           u64 objectid, u64 offset,
                           char *data, size_t len)
 {
-        return 0;
-#if 0
         int ret;
         struct btrfs_key file_key;
         struct btrfs_key found_key;
         struct btrfs_path *path;
         struct btrfs_csum_item *item;
-        struct extent_buffer *leaf;
+        struct extent_buffer *leaf = NULL;
         u64 csum_offset;
+        u32 csum_result = ~(u32)0;
 
         path = btrfs_alloc_path();
         BUG_ON(!path);
 
         file_key.objectid = objectid;
         file_key.offset = offset;
-        file_key.flags = 0;
         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
 
         item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
-        if (!IS_ERR(item))
+        if (!IS_ERR(item)) {
+                leaf = path->nodes[0];
                 goto found;
+        }
         ret = PTR_ERR(item);
         if (ret == -EFBIG) {
                 u32 item_size;
@@ -226,14 +226,15 @@ csum:
         item = (struct btrfs_csum_item *)((unsigned char *)item +
                                           csum_offset * BTRFS_CRC32_SIZE);
 found:
-        /* FIXME!!!!!!!!!!!! */
-        ret = btrfs_csum_data(root, data, len, &item->csum);
+        csum_result = btrfs_csum_data(root, data, csum_result, len);
+        btrfs_csum_final(csum_result, (char *)&csum_result);
+        write_extent_buffer(leaf, &csum_result, (unsigned long)item,
+                            BTRFS_CRC32_SIZE);
         btrfs_mark_buffer_dirty(path->nodes[0]);
 fail:
         btrfs_release_path(root, path);
         btrfs_free_path(path);
         return ret;
-#endif
 }
 
 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,