git: HAMMER VFS - Disallow rebalancing on small-memory machines

[Matthew Dillon]

:Could this be MFC to 2.4, thanks.
:Just cherry-picking works here.
:
:ENOSPC isn't the most obvious error code:
:when testing I first thought something wasn't right,
:as 'No space left on device' isn't correct.
:What about EDEADLK?
:(could match the stall I had before this commit (issue1552))
:It seems we don't have error message just saying 'resource shortage'.
:
: -thomas

    ENOSPC is better than EDEADLK.  Go ahead and MFC it.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>