K 10
svn:author
V 6
rlibby
K 8
svn:date
V 27
2019-11-27T01:54:39.747947Z
K 7
svn:log
V 699
witness: sleepable rm locks are not sleepable in read mode

There are two classes of rm lock, one "sleepable" and one not.  But even
a "sleepable" rm lock is only sleepable in write mode, and is
non-sleepable when taken in read mode.

Warn about sleepable rm locks in read mode as non-sleepable locks.  Do
this by defining a new lock operation flag, LOP_NOSLEEP, to indicate
that a lock is non-sleepable despite what the LO_SLEEPABLE flag would
indicate, and defining a new witness lock instance flag, LI_SLEEPABLE,
to track the product of LO_SLEEPABLE and LOP_NOSLEEP on the lock
instance.

Reviewed by:	markj
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D22527

END