1 files changed, 110 insertions, 14 deletions

diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index c936dd14de41..1f17f3d93727 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -26,6 +26,87 @@
 #ifndef NET_9P_CLIENT_H
 #define NET_9P_CLIENT_H
 
+/* Number of requests per row */
+#define P9_ROW_MAXTAG 255
+
+/**
+ * enum p9_trans_status - different states of underlying transports
+ * @Connected: transport is connected and healthy
+ * @Disconnected: transport has been disconnected
+ * @Hung: transport is connected by wedged
+ *
+ * This enumeration details the various states a transport
+ * instatiation can be in.
+ */
+
+enum p9_trans_status {
+        Connected,
+        Disconnected,
+        Hung,
+};
+
+/**
+ * enum p9_req_status_t - virtio request status
+ * @REQ_STATUS_IDLE: request slot unused
+ * @REQ_STATUS_ALLOC: request has been allocated but not sent
+ * @REQ_STATUS_UNSENT: request waiting to be sent
+ * @REQ_STATUS_SENT: request sent to server
+ * @REQ_STATUS_FLSH: a flush has been sent for this request
+ * @REQ_STATUS_RCVD: response received from server
+ * @REQ_STATUS_FLSHD: request has been flushed
+ * @REQ_STATUS_ERROR: request encountered an error on the client side
+ *
+ * The @REQ_STATUS_IDLE state is used to mark a request slot as unused
+ * but use is actually tracked by the idpool structure which handles tag
+ * id allocation.
+ *
+ */
+
+enum p9_req_status_t {
+        REQ_STATUS_IDLE,
+        REQ_STATUS_ALLOC,
+        REQ_STATUS_UNSENT,
+        REQ_STATUS_SENT,
+        REQ_STATUS_FLSH,
+        REQ_STATUS_RCVD,
+        REQ_STATUS_FLSHD,
+        REQ_STATUS_ERROR,
+};
+
+/**
+ * struct p9_req_t - request slots
+ * @status: status of this request slot
+ * @t_err: transport error
+ * @flush_tag: tag of request being flushed (for flush requests)
+ * @wq: wait_queue for the client to block on for this request
+ * @tc: the request fcall structure
+ * @rc: the response fcall structure
+ * @aux: transport specific data (provided for trans_fd migration)
+ * @req_list: link for higher level objects to chain requests
+ *
+ * Transport use an array to track outstanding requests
+ * instead of a list.  While this may incurr overhead during initial
+ * allocation or expansion, it makes request lookup much easier as the
+ * tag id is a index into an array.  (We use tag+1 so that we can accomodate
+ * the -1 tag for the T_VERSION request).
+ * This also has the nice effect of only having to allocate wait_queues
+ * once, instead of constantly allocating and freeing them.  Its possible
+ * other resources could benefit from this scheme as well.
+ *
+ */
+
+struct p9_req_t {
+        int status;
+        int t_err;
+        u16 flush_tag;
+        wait_queue_head_t *wq;
+        struct p9_fcall *tc;
+        struct p9_fcall *rc;
+        void *aux;
+
+        struct list_head req_list;
+};
+
 /**
  * struct p9_client - per client instance state
  * @lock: protect @fidlist
@@ -36,9 +117,20 @@
  * @conn: connection state information used by trans_fd
  * @fidpool: fid handle accounting for session
  * @fidlist: List of active fid handles
+ * @tagpool - transaction id accounting for session
+ * @reqs - 2D array of requests
+ * @max_tag - current maximum tag id allocated
  *
  * The client structure is used to keep track of various per-client
  * state that has been instantiated.
+ * In order to minimize per-transaction overhead we use a
+ * simple array to lookup requests instead of a hash table
+ * or linked list.  In order to support larger number of
+ * transactions, we make this a 2D array, allocating new rows
+ * when we need to grow the total number of the transactions.
+ *
+ * Each row is 256 requests and we'll support up to 256 rows for
+ * a total of 64k concurrent requests per session.
  *
  * Bugs: duplicated data and potentially unnecessary elements.
  */
@@ -48,11 +140,16 @@ struct p9_client {
         int msize;
         unsigned char dotu;
         struct p9_trans_module *trans_mod;
-        struct p9_trans *trans;
+        enum p9_trans_status status;
+        void *trans;
         struct p9_conn *conn;
 
         struct p9_idpool *fidpool;
         struct list_head fidlist;
+
+        struct p9_idpool *tagpool;
+        struct p9_req_t *reqs[P9_ROW_MAXTAG];
+        int max_tag;
 };
 
 /**
@@ -65,8 +162,6 @@ struct p9_client {
  * @uid: the numeric uid of the local user who owns this handle
  * @aux: transport specific information (unused?)
  * @rdir_fpos: tracks offset of file position when reading directory contents
- * @rdir_pos: (unused?)
- * @rdir_fcall: holds response of last directory read request
  * @flist: per-client-instance fid tracking
  * @dlist: per-dentry fid tracking
  *
@@ -83,8 +178,6 @@ struct p9_fid {
         void *aux;
 
         int rdir_fpos;
-        int rdir_pos;
-        struct p9_fcall *rdir_fcall;
         struct list_head flist;
         struct list_head dlist; /* list of all fids attached to a dentry */
 };
@@ -103,15 +196,18 @@ int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
                                                         char *extension);
 int p9_client_clunk(struct p9_fid *fid);
 int p9_client_remove(struct p9_fid *fid);
-int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count);
-int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count);
-int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count);
-int p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset,
-                                                                u32 count);
-int p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset,
-                                                                u32 count);
-struct p9_stat *p9_client_stat(struct p9_fid *fid);
+int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
+                                                        u64 offset, u32 count);
+int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
+                                                        u64 offset, u32 count);
+struct p9_wstat *p9_client_stat(struct p9_fid *fid);
 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
-struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset);
+
+struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
+void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
+
+int p9stat_read(char *, int, struct p9_wstat *, int);
+void p9stat_free(struct p9_wstat *);
+
 
 #endif /* NET_9P_CLIENT_H */