e2fsck: skip sorting extents if there are no valid extents

At the end of a fast commit replay, e2fsck tries merging extents in a
inode. This patch fixes a bug in this logic where we were continuing
this action even if there were no extents to merge resulting in
accessing illegal memory.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>

diff --git a/e2fsck/journal.c b/e2fsck/journal.c
index fe4e018..2e86723 100644 (file)
--- a/e2fsck/journal.c
+++ b/e2fsck/journal.c
@@ -464,6 +464,9 @@ static void ex_sort_and_merge(struct extent_list *list)
                }
        }
 
+       if (list->count == 0)
+               return;
+
        /* Now sort by logical offset */
        qsort(list->extents, list->count, sizeof(list->extents[0]),
                ex_compar);