nfsd41: use globals for DRC limits

The version 4.1 DRC memory limit and tracking variables are server wide and
session specific. Replace struct svc_serv fields with globals.
Stop using the svc_serv sv_lock.

Add a spinlock to serialize access to the DRC limit management variables which
change on session creation and deletion (usage counter) or (future)
administrative action to adjust the total DRC memory limit.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
index 2b49d676d0c9..2571f856908f 100644
--- a/include/linux/nfsd/nfsd.h
+++ b/include/linux/nfsd/nfsd.h
@@ -56,6 +56,9 @@ extern struct svc_version	nfsd_version2, nfsd_version3,
 extern u32                      nfsd_supported_minorversion;
 extern struct mutex             nfsd_mutex;
 extern struct svc_serv          *nfsd_serv;
+extern spinlock_t               nfsd_drc_lock;
+extern unsigned int             nfsd_drc_max_pages;
+extern unsigned int             nfsd_drc_pages_used;
 
 extern struct seq_operations nfs_exports_op;