Btrfs: Implement generation numbers in block pointers

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

1 files changed, 16 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 3b16051b121b..5697705f7530 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -114,6 +114,9 @@ static int __btrfs_cow_block(struct btrfs_trans_handle *trans,
         } else {
                 btrfs_set_node_blockptr(parent, parent_slot,
                                         cow->start);
+                WARN_ON(trans->transid == 0);
+                btrfs_set_node_ptr_generation(parent, parent_slot,
+                                              trans->transid);
                 btrfs_mark_buffer_dirty(parent);
                 WARN_ON(btrfs_header_generation(parent) != trans->transid);
                 btrfs_free_extent(trans, root, buf->start, buf->len, 1);
@@ -967,6 +970,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
 {
         struct extent_buffer *b;
         u64 bytenr;
+        u64 ptr_gen;
         int slot;
         int ret;
         int level;
@@ -1031,10 +1035,18 @@ again:
                         if (level == lowest_level)
                                 break;
                         bytenr = btrfs_node_blockptr(b, slot);
+                        ptr_gen = btrfs_node_ptr_generation(b, slot);
                         if (should_reada)
                                 reada_for_search(root, p, level, slot);
                         b = read_tree_block(root, bytenr,
                                             btrfs_level_size(root, level - 1));
+                        if (ptr_gen != btrfs_header_generation(b)) {
+                                printk("block %llu bad gen wanted %llu "
+                                       "found %llu\n",
+                                (unsigned long long)b->start,
+                                (unsigned long long)ptr_gen,
+                                (unsigned long long)btrfs_header_generation(b));
+                        }
                 } else {
                         p->slots[level] = slot;
                         if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
@@ -1218,6 +1230,8 @@ static int insert_new_root(struct btrfs_trans_handle *trans,
                 btrfs_node_key(lower, &lower_key, 0);
         btrfs_set_node_key(c, &lower_key, 0);
         btrfs_set_node_blockptr(c, 0, lower->start);
+        WARN_ON(btrfs_header_generation(lower) == 0);
+        btrfs_set_node_ptr_generation(c, 0, btrfs_header_generation(lower));
 
         btrfs_mark_buffer_dirty(c);
 
@@ -1261,6 +1275,8 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
         }
         btrfs_set_node_key(lower, key, slot);
         btrfs_set_node_blockptr(lower, slot, bytenr);
+        WARN_ON(trans->transid == 0);
+        btrfs_set_node_ptr_generation(lower, slot, trans->transid);
         btrfs_set_header_nritems(lower, nritems + 1);
         btrfs_mark_buffer_dirty(lower);
         return 0;