btrfs: selftests: remove impossible inline extent at non-zero file offset

In our inode-tests.c, we create an inline offset at file offset 5, which
is no longer possible since the introduction of tree-checker.

Thus I don't think we should spend time maintaining some corner cases
which are already ruled out by tree-checker.

So this patch will:

- Change the inline extent to start at file offset 0

  Also change its length to 6 to cover the original length

- Add an extra ASSERT() for btrfs_add_extent_mapping()

  This is to make sure tree-checker is working correctly.

- Update the inode selftest

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index cd45303f344d..4a4362f5cc52 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -638,6 +638,13 @@ int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
 	int ret;
 	struct extent_map *em = *em_in;
 
+	/*
+	 * Tree-checker should have rejected any inline extent with non-zero
+	 * file offset. Here just do a sanity check.
+	 */
+	if (em->block_start == EXTENT_MAP_INLINE)
+		ASSERT(em->start == 0);
+
 	ret = add_extent_mapping(em_tree, em, 0);
 	/* it is possible that someone inserted the extent into the tree
 	 * while we had the lock dropped.  It is also possible that