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
33 * enum p9_trans_status - different states of underlying transports
34 * @Connected: transport is connected and healthy
35 * @Disconnected: transport has been disconnected
36 * @Hung: transport is connected by wedged
38 * This enumeration details the various states a transport
39 * instatiation can be in.
42 enum p9_trans_status {
49 * enum p9_req_status_t - virtio request status
50 * @REQ_STATUS_IDLE: request slot unused
51 * @REQ_STATUS_ALLOC: request has been allocated but not sent
52 * @REQ_STATUS_UNSENT: request waiting to be sent
53 * @REQ_STATUS_SENT: request sent to server
54 * @REQ_STATUS_FLSH: a flush has been sent for this request
55 * @REQ_STATUS_RCVD: response received from server
56 * @REQ_STATUS_FLSHD: request has been flushed
57 * @REQ_STATUS_ERROR: request encountered an error on the client side
59 * The @REQ_STATUS_IDLE state is used to mark a request slot as unused
60 * but use is actually tracked by the idpool structure which handles tag
65 enum p9_req_status_t {
77 * struct p9_req_t - request slots
78 * @status: status of this request slot
79 * @t_err: transport error
80 * @wq: wait_queue for the client to block on for this request
81 * @tc: the request fcall structure
82 * @rc: the response fcall structure
83 * @aux: transport specific data (provided for trans_fd migration)
84 * @tag: tag on request (BUG: redundant)
85 * @req_list: link for higher level objects to chain requests
87 * Transport use an array to track outstanding requests
88 * instead of a list. While this may incurr overhead during initial
89 * allocation or expansion, it makes request lookup much easier as the
90 * tag id is a index into an array. (We use tag+1 so that we can accomodate
91 * the -1 tag for the T_VERSION request).
92 * This also has the nice effect of only having to allocate wait_queues
93 * once, instead of constantly allocating and freeing them. Its possible
94 * other resources could benefit from this scheme as well.
101 wait_queue_head_t *wq;
108 struct list_head req_list;
112 * struct p9_client - per client instance state
113 * @lock: protect @fidlist
114 * @msize: maximum data size negotiated by protocol
115 * @dotu: extension flags negotiated by protocol
116 * @trans_mod: module API instantiated with this client
117 * @trans: tranport instance state and API
118 * @conn: connection state information used by trans_fd
119 * @fidpool: fid handle accounting for session
120 * @fidlist: List of active fid handles
121 * @tagpool - transaction id accounting for session
122 * @reqs - 2D array of requests
123 * @max_tag - current maximum tag id allocated
125 * The client structure is used to keep track of various per-client
126 * state that has been instantiated.
127 * In order to minimize per-transaction overhead we use a
128 * simple array to lookup requests instead of a hash table
129 * or linked list. In order to support larger number of
130 * transactions, we make this a 2D array, allocating new rows
131 * when we need to grow the total number of the transactions.
133 * Each row is 256 requests and we'll support up to 256 rows for
134 * a total of 64k concurrent requests per session.
136 * Bugs: duplicated data and potentially unnecessary elements.
140 spinlock_t lock; /* protect client structure */
143 struct p9_trans_module *trans_mod;
144 enum p9_trans_status status;
146 struct p9_conn *conn;
148 struct p9_idpool *fidpool;
149 struct list_head fidlist;
151 struct p9_idpool *tagpool;
152 struct p9_req_t *reqs[P9_ROW_MAXTAG];
157 * struct p9_fid - file system entity handle
158 * @clnt: back pointer to instantiating &p9_client
159 * @fid: numeric identifier for this handle
160 * @mode: current mode of this fid (enum?)
161 * @qid: the &p9_qid server identifier this handle points to
162 * @iounit: the server reported maximum transaction size for this file
163 * @uid: the numeric uid of the local user who owns this handle
164 * @aux: transport specific information (unused?)
165 * @rdir_fpos: tracks offset of file position when reading directory contents
166 * @rdir_pos: (unused?)
167 * @rdir_fcall: holds response of last directory read request
168 * @flist: per-client-instance fid tracking
169 * @dlist: per-dentry fid tracking
171 * TODO: This needs lots of explanation.
175 struct p9_client *clnt;
185 struct p9_fcall *rdir_fcall;
186 struct list_head flist;
187 struct list_head dlist; /* list of all fids attached to a dentry */
190 struct p9_client *p9_client_create(const char *dev_name, char *options);
191 void p9_client_destroy(struct p9_client *clnt);
192 void p9_client_disconnect(struct p9_client *clnt);
193 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
194 char *uname, u32 n_uname, char *aname);
195 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
196 u32 n_uname, char *aname);
197 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
199 int p9_client_open(struct p9_fid *fid, int mode);
200 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
202 int p9_client_clunk(struct p9_fid *fid);
203 int p9_client_remove(struct p9_fid *fid);
204 int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count);
205 int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count);
206 int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count);
207 int p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset,
209 int p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset,
211 struct p9_stat *p9_client_stat(struct p9_fid *fid);
212 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
213 struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset);
215 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
216 void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
218 #endif /* NET_9P_CLIENT_H */