Recovery partition in the middle of the file system
To fix:


Boot into the OS as normal.
Open a terminal and type: diskutil list
Repair the disk: diskutil repairVolume /dev/disk0s3 (where disk0s3 is your recovery disk)
Verify the disk: diskutil verifyVolume /dev/disk0s3
Resize the partition: sudo diskutil resizeVolume /dev/disk0s3 650M (and enter your Mac passcode)


If successful, restart your Mac and after open disk utility and resize your core partition. Done.