ACK: [REGRESSION/bionic] ext4: fix false negatives *and* false positives in ext4_check_descriptors()

[Tyler Hicks]

On 2019-01-29 16:08:58, Stefan Bader wrote:
> From: Theodore Ts'o <tytso at mit.edu>
> 
> BugLink: https://bugs.launchpad.net/bugs/1813727
> 
> Ext4_check_descriptors() was getting called before s_gdb_count was
> initialized.  So for file systems w/o the meta_bg feature, allocation
> bitmaps could overlap the block group descriptors and ext4 wouldn't
> notice.
> 
> For file systems with the meta_bg feature enabled, there was a
> fencepost error which would cause the ext4_check_descriptors() to
> incorrectly believe that the block allocation bitmap overlaps with the
> block group descriptor blocks, and it would reject the mount.
> 
> Fix both of these problems.
> 
> Signed-off-by: Theodore Ts'o <tytso at mit.edu>
> Cc: stable at vger.kernel.org
> 
> (cherry picked from commit 44de022c4382541cebdd6de4465d1f4f465ff1dd)
> Signed-off-by: Stefan Bader <stefan.bader at canonical.com>
> ---

Acked-by: Tyler Hicks <tyhicks at canonical.com>

Tyler