5.3.12 xfs: System hangs during xfs_fsr on two-extent files with speculative preallocation

During an xfs_fsr process on extents that are generated by speculative preallocation, the code that determines whether all of the extents fit inline miscalculates because the di_nextents call that is used does not account for these extents. This results in corruption of the in-memory inode, and ultimately the code attempts to move memory structures using incorrectly calculated ranges. This causes a kernel panic. (Bug ID 25333211)