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, 5 insertions, 5 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 980a216a48c8..2e6a44e3d2fe 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -430,11 +430,11 @@ static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan)
         else if (fchan->maxreqs > NFSD_MAX_SLOTS_PER_SESSION)
                 fchan->maxreqs = NFSD_MAX_SLOTS_PER_SESSION;
 
-        spin_lock(&nfsd_serv->sv_lock);
-        if (np + nfsd_serv->sv_drc_pages_used > nfsd_serv->sv_drc_max_pages)
-                np = nfsd_serv->sv_drc_max_pages - nfsd_serv->sv_drc_pages_used;
-        nfsd_serv->sv_drc_pages_used += np;
-        spin_unlock(&nfsd_serv->sv_lock);
+        spin_lock(&nfsd_drc_lock);
+        if (np + nfsd_drc_pages_used > nfsd_drc_max_pages)
+                np = nfsd_drc_max_pages - nfsd_drc_pages_used;
+        nfsd_drc_pages_used += np;
+        spin_unlock(&nfsd_drc_lock);
 
         if (np <= 0) {
                 status = nfserr_resource;