#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_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_ERR: 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_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
+ * @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)
+ *
+ * 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;
+ wait_queue_head_t *wq;
+ struct p9_fcall *tc;
+ struct p9_fcall *rc;
+ u16 flush_tag;
+ void *aux;
+};
+
+/**
+ * struct p9_client - per client instance state
+ * @lock: protect @fidlist
+ * @msize: maximum data size negotiated by protocol
+ * @dotu: extension flags negotiated by protocol
+ * @trans_mod: module API instantiated with this client
+ * @trans: tranport instance state and API
+ * @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.
+ */
+
struct p9_client {
spinlock_t lock; /* protect client structure */
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;
};
+/**
+ * struct p9_fid - file system entity handle
+ * @clnt: back pointer to instantiating &p9_client
+ * @fid: numeric identifier for this handle
+ * @mode: current mode of this fid (enum?)
+ * @qid: the &p9_qid server identifier this handle points to
+ * @iounit: the server reported maximum transaction size for this file
+ * @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
+ *
+ * TODO: This needs lots of explanation.
+ */
+
struct p9_fid {
struct p9_client *clnt;
u32 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_alloc(struct p9_client *, u16);
+struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
+
#endif /* NET_9P_CLIENT_H */
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