1 files changed, 17 insertions, 0 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index e07f3376b7df..a5ce99a6c936 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -4396,6 +4396,23 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
         logged_end = end;
 
         list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
+                /*
+                 * Skip extents outside our logging range. It's important to do
+                 * it for correctness because if we don't ignore them, we may
+                 * log them before their ordered extent completes, and therefore
+                 * we could log them without logging their respective checksums
+                 * (the checksum items are added to the csum tree at the very
+                 * end of btrfs_finish_ordered_io()). Also leave such extents
+                 * outside of our range in the list, since we may have another
+                 * ranged fsync in the near future that needs them. If an extent
+                 * outside our range corresponds to a hole, log it to avoid
+                 * leaving gaps between extents (fsck will complain when we are
+                 * not using the NO_HOLES feature).
+                 */
+                if ((em->start > end || em->start + em->len <= start) &&
+                    em->block_start != EXTENT_MAP_HOLE)
+                        continue;
+
                 list_del_init(&em->list);
                 /*
                  * Just an arbitrary number, this can be really CPU intensive