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, 9 insertions, 8 deletions

diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index c0e734082dcc..7b598b070700 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -89,7 +89,7 @@ static int add_new_free_space_info(struct btrfs_trans_handle *trans,
 			      struct btrfs_free_space_info);
 	btrfs_set_free_space_extent_count(leaf, info, 0);
 	btrfs_set_free_space_flags(leaf, info, 0);
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 
 	ret = 0;
 out:
@@ -287,7 +287,7 @@ int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
 	flags |= BTRFS_FREE_SPACE_USING_BITMAPS;
 	btrfs_set_free_space_flags(leaf, info, flags);
 	expected_extent_count = btrfs_free_space_extent_count(leaf, info);
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 	btrfs_release_path(path);
 
 	if (extent_count != expected_extent_count) {
@@ -324,7 +324,7 @@ int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
 		ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
 		write_extent_buffer(leaf, bitmap_cursor, ptr,
 				    data_size);
-		btrfs_mark_buffer_dirty(leaf);
+		btrfs_mark_buffer_dirty(trans, leaf);
 		btrfs_release_path(path);
 
 		i += extent_size;
@@ -430,7 +430,7 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
 	flags &= ~BTRFS_FREE_SPACE_USING_BITMAPS;
 	btrfs_set_free_space_flags(leaf, info, flags);
 	expected_extent_count = btrfs_free_space_extent_count(leaf, info);
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 	btrfs_release_path(path);
 
 	nrbits = block_group->length >> block_group->fs_info->sectorsize_bits;
@@ -495,7 +495,7 @@ static int update_free_space_extent_count(struct btrfs_trans_handle *trans,
 
 	extent_count += new_extents;
 	btrfs_set_free_space_extent_count(path->nodes[0], info, extent_count);
-	btrfs_mark_buffer_dirty(path->nodes[0]);
+	btrfs_mark_buffer_dirty(trans, path->nodes[0]);
 	btrfs_release_path(path);
 
 	if (!(flags & BTRFS_FREE_SPACE_USING_BITMAPS) &&
@@ -533,7 +533,8 @@ int free_space_test_bit(struct btrfs_block_group *block_group,
 	return !!extent_buffer_test_bit(leaf, ptr, i);
 }
 
-static void free_space_set_bits(struct btrfs_block_group *block_group,
+static void free_space_set_bits(struct btrfs_trans_handle *trans,
+				struct btrfs_block_group *block_group,
 				struct btrfs_path *path, u64 *start, u64 *size,
 				int bit)
 {
@@ -563,7 +564,7 @@ static void free_space_set_bits(struct btrfs_block_group *block_group,
 		extent_buffer_bitmap_set(leaf, ptr, first, last - first);
 	else
 		extent_buffer_bitmap_clear(leaf, ptr, first, last - first);
-	btrfs_mark_buffer_dirty(leaf);
+	btrfs_mark_buffer_dirty(trans, leaf);
 
 	*size -= end - *start;
 	*start = end;
@@ -656,7 +657,7 @@ static int modify_free_space_bitmap(struct btrfs_trans_handle *trans,
 	cur_start = start;
 	cur_size = size;
 	while (1) {
-		free_space_set_bits(block_group, path, &cur_start, &cur_size,
+		free_space_set_bits(trans, block_group, path, &cur_start, &cur_size,
 				    !remove);
 		if (cur_size == 0)
 			break;