K 10
svn:author
V 8
rmacklem
K 8
svn:date
V 27
2022-05-16T19:28:39.893543Z
K 7
svn:log
V 841
nfsd: Fix session slot freeing for NFSv4.1/4.2

Without this patch the NFSv4.1/4.2 server erroneously
always frees session slot zero for callbacks.  This only
affects 4.1/4.2 mounts if the server has delegations
enabled or is a pNFS configuration.  Even for those
cases, the effect is mainly to only use slot 0 for
callbacks, serializing all of them.  There is a slight
chance that callbacks will fail if the client performs
them in a different order than received on the TCP
connection.

If this bug affects your server, you will see console
messages like:
  newnfs_request: Bad session slot

This patch fixes the problem.  Found during a recent
IETF NFSv4 testing event.

PR:	263728

(cherry picked from commit 271f6d52a606e86c11b366082f11fe69350f24da)

Git Hash:   81091a7ca11acd5adcc673ffd06f8e08791386ea
Git Author: rmacklem@FreeBSD.org
END