while chasing for I/O performance issues in virtualized environments (usecase
Open Build Service package builds for example), I noticed that btrfs in our
default kernel has asserts enabled. according to the Kconfig help setting, this
setting is purely for development purposes. 

I suggested to move the setting CONFIG_BTRFS_ASSERT only into the debug
flavors, however there was concerns that this affects finding memory
corruptions and other hardware related issues. 

On the other side, in my brief testing it appeared disabling reduced code size
noticeably (in dual-digit percentage range) and also improved IOPS on a FIO
randrw test (on a cow file) by over 20%. I will replicate the tests to be sure. 

This bug is to track how to address the issue and making asserts purely
developer only and disable them in production builds of the openSUSE
distribution.