xfs: fix log reservation overflows when allocating large rt extents
Omar Sandoval reported that a 4G fallocate on the realtime device causes
filesystem shutdowns due to a log reservation overflow that happens when
we log the rtbitmap updates. Factor rtbitmap/rtsummary updates into the
the tr_write and tr_itruncate log reservation calculation.
"The following reproducer results in a transaction log overrun warning
for me: