3 files changed, 54 insertions, 7 deletions

diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index 9c6ec78e47a5..13abe013af21 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -331,6 +331,9 @@ enum p9_qid_t {
 /* size of header for zero copy read/write */
 #define P9_ZC_HDR_SZ 4096
 
+/* maximum length of an error string */
+#define P9_ERRMAX 128
+
 /**
  * struct p9_qid - file system entity information
  * @type: 8-bit type &p9_qid_t
@@ -551,6 +554,4 @@ struct p9_fcall {
 int p9_errstr2errno(char *errstr, int len);
 
 int p9_error_init(void);
-int p9_trans_fd_init(void);
-void p9_trans_fd_exit(void);
 #endif /* NET_9P_H */
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index ec1d1706f43c..78ebcf782ce5 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -11,6 +11,7 @@
 
 #include <linux/utsname.h>
 #include <linux/idr.h>
+#include <linux/tracepoint-defs.h>
 
 /* Number of requests per row */
 #define P9_ROW_MAXTAG 255
@@ -76,7 +77,7 @@ enum p9_req_status_t {
 struct p9_req_t {
 	int status;
 	int t_err;
-	struct kref refcount;
+	refcount_t refcount;
 	wait_queue_head_t wq;
 	struct p9_fcall tc;
 	struct p9_fcall rc;
@@ -227,15 +228,55 @@ struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag);
 
 static inline void p9_req_get(struct p9_req_t *r)
 {
-	kref_get(&r->refcount);
+	refcount_inc(&r->refcount);
 }
 
 static inline int p9_req_try_get(struct p9_req_t *r)
 {
-	return kref_get_unless_zero(&r->refcount);
+	return refcount_inc_not_zero(&r->refcount);
 }
 
-int p9_req_put(struct p9_req_t *r);
+int p9_req_put(struct p9_client *c, struct p9_req_t *r);
+
+/* We cannot have the real tracepoints in header files,
+ * use a wrapper function */
+DECLARE_TRACEPOINT(9p_fid_ref);
+void do_trace_9p_fid_get(struct p9_fid *fid);
+void do_trace_9p_fid_put(struct p9_fid *fid);
+
+/* fid reference counting helpers:
+ *  - fids used for any length of time should always be referenced through
+ *    p9_fid_get(), and released with p9_fid_put()
+ *  - v9fs_fid_lookup() or similar will automatically call get for you
+ *    and also require a put
+ *  - the *_fid_add() helpers will stash the fid in the inode,
+ *    at which point it is the responsibility of evict_inode()
+ *    to call the put
+ *  - the last put will automatically send a clunk to the server
+ */
+static inline struct p9_fid *p9_fid_get(struct p9_fid *fid)
+{
+	if (tracepoint_enabled(9p_fid_ref))
+		do_trace_9p_fid_get(fid);
+
+	refcount_inc(&fid->count);
+
+	return fid;
+}
+
+static inline int p9_fid_put(struct p9_fid *fid)
+{
+	if (!fid || IS_ERR(fid))
+		return 0;
+
+	if (tracepoint_enabled(9p_fid_ref))
+		do_trace_9p_fid_put(fid);
+
+	if (!refcount_dec_and_test(&fid->count))
+		return 0;
+
+	return p9_client_clunk(fid);
+}
 
 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
 
diff --git a/include/net/9p/transport.h b/include/net/9p/transport.h
index 15a4e6a9dbf7..766ec07c9599 100644
--- a/include/net/9p/transport.h
+++ b/include/net/9p/transport.h
@@ -19,6 +19,10 @@
  * @list: used to maintain a list of currently available transports
  * @name: the human-readable name of the transport
  * @maxsize: transport provided maximum packet size
+ * @pooled_rbuffers: currently only set for RDMA transport which pulls the
+ *                   response buffers from a shared pool, and accordingly
+ *                   we're less flexible when choosing the response message
+ *                   size in this case
  * @def: set if this transport should be considered the default
  * @create: member function to create a new connection on this transport
  * @close: member function to discard a connection on this transport
@@ -38,6 +42,7 @@ struct p9_trans_module {
 	struct list_head list;
 	char *name;		/* name of transport */
 	int maxsize;		/* max message size of transport */
+	bool pooled_rbuffers;
 	int def;		/* this transport should be default */
 	struct module *owner;
 	int (*create)(struct p9_client *client,
@@ -54,7 +59,7 @@ struct p9_trans_module {
 
 void v9fs_register_trans(struct p9_trans_module *m);
 void v9fs_unregister_trans(struct p9_trans_module *m);
-struct p9_trans_module *v9fs_get_trans_by_name(char *s);
+struct p9_trans_module *v9fs_get_trans_by_name(const char *s);
 struct p9_trans_module *v9fs_get_default_trans(void);
 void v9fs_put_trans(struct p9_trans_module *m);