libext2fs: reset handle after inserting new extent

Commit 53422e moved the new extent insertion in
ext2fs_extent_set_bmap() prior to the modification of the original
extent, but the insert function left the handle pointing to the new
extent.  This left us modifying the -new- extent, instead of the
original one, and winding up with a corrupt extent tree something
like:

BLOCKS:
(0-1):588791-588792, (0):588791

We need to move back to the previous extent prior
to modification, if we inserted a new one.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
index 35b080e..4a4fd2c 100644 (file)
--- a/lib/ext2fs/extent.c
+++ b/lib/ext2fs/extent.c
@@ -1257,6 +1257,10 @@ again:
                                        EXT2_EXTENT_INSERT_AFTER, &newextent);
                        if (retval)
                                goto done;
+                       /* Now pointing at inserted extent; move back to prev */
+                       retval = ext2fs_extent_goto(handle, logical - 1);
+                       if (retval)
+                               goto done;
                }
                extent.e_len--;
                retval = ext2fs_extent_replace(handle, 0, &extent);