diff options
authorEric Sandeen <>2013-04-22 00:01:26 -0500
committerDavid Sterba <>2013-04-23 18:56:28 +0200
commit3456bf086603d11ae77b15e381d6523105f75f15 (patch)
parent4782e8ebdb583dfa3615f7b38dee729d34f62ec1 (diff)
btrfs-progs: set generation_v2 any time we write a new root
With this integration branch commit in place: 2bd1169 btrfs-progs: root_item generation_v2 is out of sync after btrfsck I started seeing generation mismatch messages from the kernel at mount time, after a fresh mkfs(!): btrfs: mismatching generation and generation_v2 found in root item... This is because the code which emits the warning does not do so if there is a mismatch but generation_v2 is 0; the above commit began setting generation_v2 to something non-zero, so the warning was emitted. The reason there is a mismatch at all is because mkfs.btrfs calls create_data_reloc_tree(), which copies a root, and then calls btrfs_set_root_generation(), bumping the original copied generation. But nothing updated generation_v2 to match on the way to disk. Fix this by updating generation_v2 in btrfs_insert_root(), as is done in the kernel. This is safe because it's a new root created by userspace, so the btrfs_root_item is guaranteed to be big enough to contain generation_v2. Signed-off-by: Eric Sandeen <>
1 files changed, 5 insertions, 0 deletions
diff --git a/root-tree.c b/root-tree.c
index c10d0684..ef2190fc 100644
--- a/root-tree.c
+++ b/root-tree.c
@@ -92,6 +92,11 @@ int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
int ret;
+ /*
+ * Make sure generation v1 and v2 match. See update_root for details.
+ */
+ btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
return ret;