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>
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index d4c9884..78d8fcd 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -67,6 +67,16 @@
DEFINE_MUTEX(nfsd_mutex);
struct svc_serv *nfsd_serv;
+/*
+ * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
+ * nfsd_drc_max_pages limits the total amount of memory available for
+ * version 4.1 DRC caches.
+ * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
+ */
+spinlock_t nfsd_drc_lock;
+unsigned int nfsd_drc_max_pages;
+unsigned int nfsd_drc_pages_used;
+
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static struct svc_stat nfsd_acl_svcstats;
static struct svc_version * nfsd_acl_version[] = {
@@ -238,11 +248,12 @@
{
/* The percent of nr_free_buffer_pages used by the V4.1 server DRC */
#define NFSD_DRC_SIZE_SHIFT 7
- nfsd_serv->sv_drc_max_pages = nr_free_buffer_pages()
+ nfsd_drc_max_pages = nr_free_buffer_pages()
>> NFSD_DRC_SIZE_SHIFT;
- nfsd_serv->sv_drc_pages_used = 0;
- dprintk("%s svc_drc_max_pages %u\n", __func__,
- nfsd_serv->sv_drc_max_pages);
+ nfsd_drc_pages_used = 0;
+ spin_lock_init(&nfsd_drc_lock);
+ dprintk("%s nfsd_drc_max_pages %u\n", __func__,
+ nfsd_drc_max_pages);
}
int nfsd_create_serv(void)