2 * include/net/9p/client.h
4 * 9P Client Definitions
6 * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to:
20 * Free Software Foundation
21 * 51 Franklin Street, Fifth Floor
22 * Boston, MA 02111-1301 USA
26 #ifndef NET_9P_CLIENT_H
27 #define NET_9P_CLIENT_H
29 /* Number of requests per row */
30 #define P9_ROW_MAXTAG 255
32 /** enum p9_proto_versions - 9P protocol versions
33 * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
34 * @p9_proto_2000u: 9P2000.u extension
35 * @p9_proto_2010L: 9P2010.L extension
38 enum p9_proto_versions{
46 * enum p9_trans_status - different states of underlying transports
47 * @Connected: transport is connected and healthy
48 * @Disconnected: transport has been disconnected
49 * @Hung: transport is connected by wedged
51 * This enumeration details the various states a transport
52 * instatiation can be in.
55 enum p9_trans_status {
62 * enum p9_req_status_t - virtio request status
63 * @REQ_STATUS_IDLE: request slot unused
64 * @REQ_STATUS_ALLOC: request has been allocated but not sent
65 * @REQ_STATUS_UNSENT: request waiting to be sent
66 * @REQ_STATUS_SENT: request sent to server
67 * @REQ_STATUS_FLSH: a flush has been sent for this request
68 * @REQ_STATUS_RCVD: response received from server
69 * @REQ_STATUS_FLSHD: request has been flushed
70 * @REQ_STATUS_ERROR: request encountered an error on the client side
72 * The @REQ_STATUS_IDLE state is used to mark a request slot as unused
73 * but use is actually tracked by the idpool structure which handles tag
78 enum p9_req_status_t {
90 * struct p9_req_t - request slots
91 * @status: status of this request slot
92 * @t_err: transport error
93 * @flush_tag: tag of request being flushed (for flush requests)
94 * @wq: wait_queue for the client to block on for this request
95 * @tc: the request fcall structure
96 * @rc: the response fcall structure
97 * @aux: transport specific data (provided for trans_fd migration)
98 * @req_list: link for higher level objects to chain requests
100 * Transport use an array to track outstanding requests
101 * instead of a list. While this may incurr overhead during initial
102 * allocation or expansion, it makes request lookup much easier as the
103 * tag id is a index into an array. (We use tag+1 so that we can accomodate
104 * the -1 tag for the T_VERSION request).
105 * This also has the nice effect of only having to allocate wait_queues
106 * once, instead of constantly allocating and freeing them. Its possible
107 * other resources could benefit from this scheme as well.
114 wait_queue_head_t *wq;
119 struct list_head req_list;
123 * struct p9_client - per client instance state
124 * @lock: protect @fidlist
125 * @msize: maximum data size negotiated by protocol
126 * @dotu: extension flags negotiated by protocol
127 * @proto_version: 9P protocol version to use
128 * @trans_mod: module API instantiated with this client
129 * @trans: tranport instance state and API
130 * @conn: connection state information used by trans_fd
131 * @fidpool: fid handle accounting for session
132 * @fidlist: List of active fid handles
133 * @tagpool - transaction id accounting for session
134 * @reqs - 2D array of requests
135 * @max_tag - current maximum tag id allocated
137 * The client structure is used to keep track of various per-client
138 * state that has been instantiated.
139 * In order to minimize per-transaction overhead we use a
140 * simple array to lookup requests instead of a hash table
141 * or linked list. In order to support larger number of
142 * transactions, we make this a 2D array, allocating new rows
143 * when we need to grow the total number of the transactions.
145 * Each row is 256 requests and we'll support up to 256 rows for
146 * a total of 64k concurrent requests per session.
148 * Bugs: duplicated data and potentially unnecessary elements.
152 spinlock_t lock; /* protect client structure */
154 unsigned char proto_version;
155 struct p9_trans_module *trans_mod;
156 enum p9_trans_status status;
158 struct p9_conn *conn;
160 struct p9_idpool *fidpool;
161 struct list_head fidlist;
163 struct p9_idpool *tagpool;
164 struct p9_req_t *reqs[P9_ROW_MAXTAG];
169 * struct p9_fid - file system entity handle
170 * @clnt: back pointer to instantiating &p9_client
171 * @fid: numeric identifier for this handle
172 * @mode: current mode of this fid (enum?)
173 * @qid: the &p9_qid server identifier this handle points to
174 * @iounit: the server reported maximum transaction size for this file
175 * @uid: the numeric uid of the local user who owns this handle
176 * @rdir: readdir accounting structure (allocated on demand)
177 * @flist: per-client-instance fid tracking
178 * @dlist: per-dentry fid tracking
180 * TODO: This needs lots of explanation.
184 struct p9_client *clnt;
193 struct list_head flist;
194 struct list_head dlist; /* list of all fids attached to a dentry */
197 int p9_client_version(struct p9_client *);
198 struct p9_client *p9_client_create(const char *dev_name, char *options);
199 void p9_client_destroy(struct p9_client *clnt);
200 void p9_client_disconnect(struct p9_client *clnt);
201 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
202 char *uname, u32 n_uname, char *aname);
203 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
204 u32 n_uname, char *aname);
205 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
207 int p9_client_open(struct p9_fid *fid, int mode);
208 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
210 int p9_client_clunk(struct p9_fid *fid);
211 int p9_client_remove(struct p9_fid *fid);
212 int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
213 u64 offset, u32 count);
214 int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
215 u64 offset, u32 count);
216 struct p9_wstat *p9_client_stat(struct p9_fid *fid);
217 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
219 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
220 void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
222 int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
223 int p9stat_read(char *, int, struct p9_wstat *, int);
224 void p9stat_free(struct p9_wstat *);
226 int p9_is_proto_dotu(struct p9_client *clnt);
227 int p9_is_proto_dotl(struct p9_client *clnt);
229 #endif /* NET_9P_CLIENT_H */