nfsd4: simplify stateid generation code, fix wraparound

Follow the recommendation from rfc3530bis for stateid generation number
wraparound, simplify some code, and fix or remove incorrect comments.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index a06f55bd38b6..c425717715f6 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -293,6 +293,9 @@ static inline void
 update_stateid(stateid_t *stateid)
 {
         stateid->si_generation++;
+        /* Wraparound recommendation from 3530bis-13 9.1.3.2: */
+        if (stateid->si_generation == 0)
+                stateid->si_generation = 1;
 }
 
 /* A reasonable value for REPLAY_ISIZE was estimated as follows: