nfsd: track memory utilization by the DRC

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

1 files changed, 17 insertions, 5 deletions

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 48f5ef944234..1f45b3353bb1 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -38,6 +38,9 @@ static unsigned int		num_drc_entries;
 /* cache misses due only to checksum comparison failures */
 static unsigned int             payload_misses;
 
+/* amount of memory (in bytes) currently consumed by the DRC */
+static unsigned int             drc_mem_usage;
+
 /*
  * Calculate the hash index from an XID.
  */
@@ -112,12 +115,15 @@ nfsd_reply_cache_alloc(void)
 static void
 nfsd_reply_cache_free_locked(struct svc_cacherep *rp)
 {
-        if (rp->c_type == RC_REPLBUFF)
+        if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) {
+                drc_mem_usage -= rp->c_replvec.iov_len;
                 kfree(rp->c_replvec.iov_base);
+        }
         if (!hlist_unhashed(&rp->c_hash))
                 hlist_del(&rp->c_hash);
         list_del(&rp->c_lru);
         --num_drc_entries;
+        drc_mem_usage -= sizeof(*rp);
         kmem_cache_free(drc_slab, rp);
 }
 
@@ -372,8 +378,10 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
         spin_unlock(&cache_lock);
         rp = nfsd_reply_cache_alloc();
         spin_lock(&cache_lock);
-        if (likely(rp))
+        if (likely(rp)) {
                 ++num_drc_entries;
+                drc_mem_usage += sizeof(*rp);
+        }
 
 search_cache:
         found = nfsd_cache_search(rqstp, csum);
@@ -415,6 +423,7 @@ search_cache:
 
         /* release any buffer */
         if (rp->c_type == RC_REPLBUFF) {
+                drc_mem_usage -= rp->c_replvec.iov_len;
                 kfree(rp->c_replvec.iov_base);
                 rp->c_replvec.iov_base = NULL;
         }
@@ -483,6 +492,7 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
         struct svc_cacherep *rp = rqstp->rq_cacherep;
         struct kvec     *resv = &rqstp->rq_res.head[0], *cachv;
         int             len;
+        size_t          bufsize = 0;
 
         if (!rp)
                 return;
@@ -504,19 +514,21 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
                 break;
         case RC_REPLBUFF:
                 cachv = &rp->c_replvec;
-                cachv->iov_base = kmalloc(len << 2, GFP_KERNEL);
+                bufsize = len << 2;
+                cachv->iov_base = kmalloc(bufsize, GFP_KERNEL);
                 if (!cachv->iov_base) {
                         nfsd_reply_cache_free(rp);
                         return;
                 }
-                cachv->iov_len = len << 2;
-                memcpy(cachv->iov_base, statp, len << 2);
+                cachv->iov_len = bufsize;
+                memcpy(cachv->iov_base, statp, bufsize);
                 break;
         case RC_NOCACHE:
                 nfsd_reply_cache_free(rp);
                 return;
         }
         spin_lock(&cache_lock);
+        drc_mem_usage += bufsize;
         lru_put_end(rp);
         rp->c_secure = rqstp->rq_secure;
         rp->c_type = cachetype;