NFSD: Convert the filecache to use rhashtable

Enable the filecache hash table to start small, then grow with the
workload. Smaller server deployments benefit because there should
be lower memory utilization. Larger server deployments should see
improved scaling with the number of open files.
Suggested-by: Jeff Layton <jlayton@kernel.org>
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/trace.h

@@ -778,7 +778,7 @@ DEFINE_NFSD_FILE_EVENT(nfsd_file_alloc);
 DEFINE_NFSD_FILE_EVENT(nfsd_file_put_final);
 DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash);
 DEFINE_NFSD_FILE_EVENT(nfsd_file_put);
-DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash_and_release_locked);
+DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash_and_dispose);
 
 TRACE_EVENT(nfsd_file_acquire,
 	TP_PROTO(
@@ -821,6 +821,67 @@ TRACE_EVENT(nfsd_file_acquire,
 			__entry->nf_file, __entry->status)
 );
 
+TRACE_EVENT(nfsd_file_insert_err,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct inode *inode,
+		unsigned int may_flags,
+		long error
+	),
+	TP_ARGS(rqstp, inode, may_flags, error),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(const void *, inode)
+		__field(unsigned long, may_flags)
+		__field(long, error)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->inode = inode;
+		__entry->may_flags = may_flags;
+		__entry->error = error;
+	),
+	TP_printk("xid=0x%x inode=%p may_flags=%s error=%ld",
+		__entry->xid, __entry->inode,
+		show_nfsd_may_flags(__entry->may_flags),
+		__entry->error
+	)
+);
+
+TRACE_EVENT(nfsd_file_cons_err,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct inode *inode,
+		unsigned int may_flags,
+		const struct nfsd_file *nf
+	),
+	TP_ARGS(rqstp, inode, may_flags, nf),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(const void *, inode)
+		__field(unsigned long, may_flags)
+		__field(unsigned int, nf_ref)
+		__field(unsigned long, nf_flags)
+		__field(unsigned long, nf_may)
+		__field(const void *, nf_file)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->inode = inode;
+		__entry->may_flags = may_flags;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->nf_flags = nf->nf_flags;
+		__entry->nf_may = nf->nf_may;
+		__entry->nf_file = nf->nf_file;
+	),
+	TP_printk("xid=0x%x inode=%p may_flags=%s ref=%u nf_flags=%s nf_may=%s nf_file=%p",
+		__entry->xid, __entry->inode,
+		show_nfsd_may_flags(__entry->may_flags), __entry->nf_ref,
+		show_nf_flags(__entry->nf_flags),
+		show_nfsd_may_flags(__entry->nf_may), __entry->nf_file
+	)
+);
+
 TRACE_EVENT(nfsd_file_open,
 	TP_PROTO(struct nfsd_file *nf, __be32 status),
 	TP_ARGS(nf, status),