nfsd4: drc containerization

The nfsd duplicate reply cache should not be shared between network
namespaces.

The most straightforward way to fix this is just to move every global in
the code to per-net-namespace memory, so that's what we do.

Still todo: sort out which members of nfsd_stats should be global and
which per-net-namespace.

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

1 files changed, 35 insertions, 0 deletions

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 7c686a270d60..46240c4d9184 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -127,6 +127,41 @@ struct nfsd_net {
 	 */
 	bool *nfsd_versions;
 	bool *nfsd4_minorversions;
+
+	/*
+	 * Duplicate reply cache
+	 */
+	struct nfsd_drc_bucket   *drc_hashtbl;
+	struct kmem_cache        *drc_slab;
+
+	/* max number of entries allowed in the cache */
+	unsigned int             max_drc_entries;
+
+	/* number of significant bits in the hash value */
+	unsigned int             maskbits;
+	unsigned int             drc_hashsize;
+
+	/*
+	 * Stats and other tracking of on the duplicate reply cache. All of these and
+	 * the "rc" fields in nfsdstats are protected by the cache_lock
+	 */
+
+	/* total number of entries */
+	atomic_t                 num_drc_entries;
+
+	/* cache misses due only to checksum comparison failures */
+	unsigned int             payload_misses;
+
+	/* amount of memory (in bytes) currently consumed by the DRC */
+	unsigned int             drc_mem_usage;
+
+	/* longest hash chain seen */
+	unsigned int             longest_chain;
+
+	/* size of cache when we saw the longest hash chain */
+	unsigned int             longest_chain_cachesize;
+
+	struct shrinker		nfsd_reply_cache_shrinker;
 };
 
 /* Simple check to find out if a given net was properly initialized */