btrfs: abort transaction on generation mismatch when marking eb as dirty

When marking an extent buffer as dirty, at btrfs_mark_buffer_dirty(),
we check if its generation matches the running transaction and if not we
just print a warning. Such mismatch is an indicator that something really
went wrong and only printing a warning message (and stack trace) is not
enough to prevent a corruption. Allowing a transaction to commit with such
an extent buffer will trigger an error if we ever try to read it from disk
due to a generation mismatch with its parent generation.

So abort the current transaction with -EUCLEAN if we notice a generation
mismatch. For this we need to pass a transaction handle to
btrfs_mark_buffer_dirty() which is always available except in test code,
in which case we can pass NULL since it operates on dummy extent buffers
and all test roots have a single node/leaf (root node at level 0).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 20 insertions, 16 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 4135e6ec3d7c..cb12bfb047e7 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -575,7 +575,7 @@ static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
 			btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
 		}
 	}
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 	ret = 0;
 fail:
 	btrfs_release_path(path);
@@ -623,7 +623,7 @@ static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
 			btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
 		else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
 			btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
-		btrfs_mark_buffer_dirty(leaf);
+		btrfs_mark_buffer_dirty(trans, leaf);
 	}
 	return ret;
 }
@@ -973,7 +973,7 @@ out:
  * helper to add new inline back ref
  */
 static noinline_for_stack
-void setup_inline_extent_backref(struct btrfs_fs_info *fs_info,
+void setup_inline_extent_backref(struct btrfs_trans_handle *trans,
 				 struct btrfs_path *path,
 				 struct btrfs_extent_inline_ref *iref,
 				 u64 parent, u64 root_objectid,
@@ -996,7 +996,7 @@ void setup_inline_extent_backref(struct btrfs_fs_info *fs_info,
 	type = extent_ref_type(parent, owner);
 	size = btrfs_extent_inline_ref_size(type);
 
-	btrfs_extend_item(path, size);
+	btrfs_extend_item(trans, path, size);
 
 	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
 	refs = btrfs_extent_refs(leaf, ei);
@@ -1030,7 +1030,7 @@ void setup_inline_extent_backref(struct btrfs_fs_info *fs_info,
 	} else {
 		btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
 	}
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 }
 
 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
@@ -1063,7 +1063,9 @@ static int lookup_extent_backref(struct btrfs_trans_handle *trans,
 /*
  * helper to update/remove inline back ref
  */
-static noinline_for_stack int update_inline_extent_backref(struct btrfs_path *path,
+static noinline_for_stack int update_inline_extent_backref(
+				  struct btrfs_trans_handle *trans,
+				  struct btrfs_path *path,
 				  struct btrfs_extent_inline_ref *iref,
 				  int refs_to_mod,
 				  struct btrfs_delayed_extent_op *extent_op)
@@ -1171,9 +1173,9 @@ static noinline_for_stack int update_inline_extent_backref(struct btrfs_path *pa
 			memmove_extent_buffer(leaf, ptr, ptr + size,
 					      end - ptr - size);
 		item_size -= size;
-		btrfs_truncate_item(path, item_size, 1);
+		btrfs_truncate_item(trans, path, item_size, 1);
 	}
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 	return 0;
 }
 
@@ -1203,9 +1205,10 @@ int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
 				   bytenr, num_bytes, root_objectid, path->slots[0]);
 			return -EUCLEAN;
 		}
-		ret = update_inline_extent_backref(path, iref, refs_to_add, extent_op);
+		ret = update_inline_extent_backref(trans, path, iref,
+						   refs_to_add, extent_op);
 	} else if (ret == -ENOENT) {
-		setup_inline_extent_backref(trans->fs_info, path, iref, parent,
+		setup_inline_extent_backref(trans, path, iref, parent,
 					    root_objectid, owner, offset,
 					    refs_to_add, extent_op);
 		ret = 0;
@@ -1223,7 +1226,8 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
 
 	BUG_ON(!is_data && refs_to_drop != 1);
 	if (iref)
-		ret = update_inline_extent_backref(path, iref, -refs_to_drop, NULL);
+		ret = update_inline_extent_backref(trans, path, iref,
+						   -refs_to_drop, NULL);
 	else if (is_data)
 		ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
 	else
@@ -1506,7 +1510,7 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 	if (extent_op)
 		__run_delayed_extent_op(extent_op, leaf, item);
 
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 	btrfs_release_path(path);
 
 	/* now insert the actual backref */
@@ -1670,7 +1674,7 @@ again:
 	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
 	__run_delayed_extent_op(extent_op, leaf, ei);
 
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 out:
 	btrfs_free_path(path);
 	return ret;
@@ -3149,7 +3153,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 			}
 		} else {
 			btrfs_set_extent_refs(leaf, ei, refs);
-			btrfs_mark_buffer_dirty(leaf);
+			btrfs_mark_buffer_dirty(trans, leaf);
 		}
 		if (found_extent) {
 			ret = remove_extent_backref(trans, extent_root, path,
@@ -4657,7 +4661,7 @@ static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 		btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
 	}
 
-	btrfs_mark_buffer_dirty(path->nodes[0]);
+	btrfs_mark_buffer_dirty(trans, path->nodes[0]);
 	btrfs_free_path(path);
 
 	return alloc_reserved_extent(trans, ins->objectid, ins->offset);
@@ -4732,7 +4736,7 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 		btrfs_set_extent_inline_ref_offset(leaf, iref, ref->root);
 	}
 
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 	btrfs_free_path(path);
 
 	return alloc_reserved_extent(trans, node->bytenr, fs_info->nodesize);