To handle the earlier bogus ENOSPC error caused by filesystem full of block
reservation, current code falls back to non block reservation, starts to
allocate block(s) from the goal allocation block group as if there is no
block reservation.

Current code needs to re-load the corresponding block group descriptor for
the initial goal block group in this case.  The patch fixes this.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>