Cause we've added sub transaction, if it do not want to cow a block, we also
need to get new sub transid recorded.  This is used for log code to find the
most uptodate file extents.

Signed-off-by: Liu Bo <liubo2...@cn.fujitsu.com>
---
 fs/btrfs/ctree.c |   34 +++++++++++++++++++++++++++++++++-
 1 files changed, 33 insertions(+), 1 deletions(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 0c3b515..7e21fa9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -484,6 +484,33 @@ static noinline int __btrfs_cow_block(struct 
btrfs_trans_handle *trans,
        return 0;
 }
 
+static inline void update_block_generation(struct btrfs_trans_handle *trans,
+                                          struct btrfs_root *root,
+                                          struct extent_buffer *buf,
+                                          struct extent_buffer *parent,
+                                          int slot)
+{
+       /*
+        * If it does not need to cow this block, we still need to
+        * update the block's generation, for transid may have been
+        * changed during fsync.
+       */
+       if (btrfs_header_generation(buf) == trans->transid)
+               return;
+
+       if (buf == root->node) {
+               btrfs_set_header_generation(buf, trans->transid);
+               btrfs_mark_buffer_dirty(buf);
+               add_root_to_dirty_list(root);
+       } else {
+               btrfs_set_node_ptr_generation(parent, slot,
+                                             trans->transid);
+               btrfs_set_header_generation(buf, trans->transid);
+               btrfs_mark_buffer_dirty(parent);
+               btrfs_mark_buffer_dirty(buf);
+       }
+}
+
 static inline int should_cow_block(struct btrfs_trans_handle *trans,
                                   struct btrfs_root *root,
                                   struct extent_buffer *buf)
@@ -524,6 +551,7 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle 
*trans,
        }
 
        if (!should_cow_block(trans, root, buf)) {
+               update_block_generation(trans, root, buf, parent, parent_slot);
                *cow_ret = buf;
                return 0;
        }
@@ -1639,8 +1667,12 @@ again:
                         * then we don't want to set the path blocking,
                         * so we test it here
                         */
-                       if (!should_cow_block(trans, root, b))
+                       if (!should_cow_block(trans, root, b)) {
+                               update_block_generation(trans, root, b,
+                                                       p->nodes[level + 1],
+                                                       p->slots[level + 1]);
                                goto cow_done;
+                       }
 
                        btrfs_set_path_blocking(p);
 
-- 
1.6.5.2

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to