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1/*
2 * include/net/9p/client.h
3 *
4 * 9P Client Definitions
5 *
6 * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
8 *
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.
12 *
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.
17 *
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
23 *
24 */
25
26#ifndef NET_9P_CLIENT_H
27#define NET_9P_CLIENT_H
28
29#include <linux/utsname.h>
30
31/* Number of requests per row */
32#define P9_ROW_MAXTAG 255
33
34/** enum p9_proto_versions - 9P protocol versions
35 * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
36 * @p9_proto_2000u: 9P2000.u extension
37 * @p9_proto_2000L: 9P2000.L extension
38 */
39
40enum p9_proto_versions{
41 p9_proto_legacy,
42 p9_proto_2000u,
43 p9_proto_2000L,
44};
45
46
47/**
48 * enum p9_trans_status - different states of underlying transports
49 * @Connected: transport is connected and healthy
50 * @Disconnected: transport has been disconnected
51 * @Hung: transport is connected by wedged
52 *
53 * This enumeration details the various states a transport
54 * instatiation can be in.
55 */
56
57enum p9_trans_status {
58 Connected,
59 BeginDisconnect,
60 Disconnected,
61 Hung,
62};
63
64/**
65 * enum p9_req_status_t - status of a request
66 * @REQ_STATUS_IDLE: request slot unused
67 * @REQ_STATUS_ALLOC: request has been allocated but not sent
68 * @REQ_STATUS_UNSENT: request waiting to be sent
69 * @REQ_STATUS_SENT: request sent to server
70 * @REQ_STATUS_FLSH: a flush has been sent for this request
71 * @REQ_STATUS_RCVD: response received from server
72 * @REQ_STATUS_FLSHD: request has been flushed
73 * @REQ_STATUS_ERROR: request encountered an error on the client side
74 *
75 * The @REQ_STATUS_IDLE state is used to mark a request slot as unused
76 * but use is actually tracked by the idpool structure which handles tag
77 * id allocation.
78 *
79 */
80
81enum p9_req_status_t {
82 REQ_STATUS_IDLE,
83 REQ_STATUS_ALLOC,
84 REQ_STATUS_UNSENT,
85 REQ_STATUS_SENT,
86 REQ_STATUS_FLSH,
87 REQ_STATUS_RCVD,
88 REQ_STATUS_FLSHD,
89 REQ_STATUS_ERROR,
90};
91
92/**
93 * struct p9_req_t - request slots
94 * @status: status of this request slot
95 * @t_err: transport error
96 * @flush_tag: tag of request being flushed (for flush requests)
97 * @wq: wait_queue for the client to block on for this request
98 * @tc: the request fcall structure
99 * @rc: the response fcall structure
100 * @aux: transport specific data (provided for trans_fd migration)
101 * @req_list: link for higher level objects to chain requests
102 *
103 * Transport use an array to track outstanding requests
104 * instead of a list. While this may incurr overhead during initial
105 * allocation or expansion, it makes request lookup much easier as the
106 * tag id is a index into an array. (We use tag+1 so that we can accommodate
107 * the -1 tag for the T_VERSION request).
108 * This also has the nice effect of only having to allocate wait_queues
109 * once, instead of constantly allocating and freeing them. Its possible
110 * other resources could benefit from this scheme as well.
111 *
112 */
113
114struct p9_req_t {
115 int status;
116 int t_err;
117 wait_queue_head_t *wq;
118 struct p9_fcall *tc;
119 struct p9_fcall *rc;
120 void *aux;
121
122 struct list_head req_list;
123};
124
125/**
126 * struct p9_client - per client instance state
127 * @lock: protect @fidlist
128 * @msize: maximum data size negotiated by protocol
129 * @dotu: extension flags negotiated by protocol
130 * @proto_version: 9P protocol version to use
131 * @trans_mod: module API instantiated with this client
132 * @trans: tranport instance state and API
133 * @conn: connection state information used by trans_fd
134 * @fidpool: fid handle accounting for session
135 * @fidlist: List of active fid handles
136 * @tagpool - transaction id accounting for session
137 * @reqs - 2D array of requests
138 * @max_tag - current maximum tag id allocated
139 * @name - node name used as client id
140 *
141 * The client structure is used to keep track of various per-client
142 * state that has been instantiated.
143 * In order to minimize per-transaction overhead we use a
144 * simple array to lookup requests instead of a hash table
145 * or linked list. In order to support larger number of
146 * transactions, we make this a 2D array, allocating new rows
147 * when we need to grow the total number of the transactions.
148 *
149 * Each row is 256 requests and we'll support up to 256 rows for
150 * a total of 64k concurrent requests per session.
151 *
152 * Bugs: duplicated data and potentially unnecessary elements.
153 */
154
155struct p9_client {
156 spinlock_t lock; /* protect client structure */
157 unsigned int msize;
158 unsigned char proto_version;
159 struct p9_trans_module *trans_mod;
160 enum p9_trans_status status;
161 void *trans;
162 struct p9_conn *conn;
163
164 struct p9_idpool *fidpool;
165 struct list_head fidlist;
166
167 struct p9_idpool *tagpool;
168 struct p9_req_t *reqs[P9_ROW_MAXTAG];
169 int max_tag;
170
171 char name[__NEW_UTS_LEN + 1];
172};
173
174/**
175 * struct p9_fid - file system entity handle
176 * @clnt: back pointer to instantiating &p9_client
177 * @fid: numeric identifier for this handle
178 * @mode: current mode of this fid (enum?)
179 * @qid: the &p9_qid server identifier this handle points to
180 * @iounit: the server reported maximum transaction size for this file
181 * @uid: the numeric uid of the local user who owns this handle
182 * @rdir: readdir accounting structure (allocated on demand)
183 * @flist: per-client-instance fid tracking
184 * @dlist: per-dentry fid tracking
185 *
186 * TODO: This needs lots of explanation.
187 */
188
189struct p9_fid {
190 struct p9_client *clnt;
191 u32 fid;
192 int mode;
193 struct p9_qid qid;
194 u32 iounit;
195 kuid_t uid;
196
197 void *rdir;
198
199 struct list_head flist;
200 struct hlist_node dlist; /* list of all fids attached to a dentry */
201};
202
203/**
204 * struct p9_dirent - directory entry structure
205 * @qid: The p9 server qid for this dirent
206 * @d_off: offset to the next dirent
207 * @d_type: type of file
208 * @d_name: file name
209 */
210
211struct p9_dirent {
212 struct p9_qid qid;
213 u64 d_off;
214 unsigned char d_type;
215 char d_name[256];
216};
217
218int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
219int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
220 const char *name);
221int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
222 struct p9_fid *newdirfid, const char *new_name);
223struct p9_client *p9_client_create(const char *dev_name, char *options);
224void p9_client_destroy(struct p9_client *clnt);
225void p9_client_disconnect(struct p9_client *clnt);
226void p9_client_begin_disconnect(struct p9_client *clnt);
227struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
228 char *uname, kuid_t n_uname, char *aname);
229struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
230 char **wnames, int clone);
231int p9_client_open(struct p9_fid *fid, int mode);
232int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
233 char *extension);
234int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname);
235int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, kgid_t gid,
236 struct p9_qid *qid);
237int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
238 kgid_t gid, struct p9_qid *qid);
239int p9_client_clunk(struct p9_fid *fid);
240int p9_client_fsync(struct p9_fid *fid, int datasync);
241int p9_client_remove(struct p9_fid *fid);
242int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
243int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
244 u64 offset, u32 count);
245int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
246 u64 offset, u32 count);
247int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
248int p9dirent_read(struct p9_client *clnt, char *buf, int len,
249 struct p9_dirent *dirent);
250struct p9_wstat *p9_client_stat(struct p9_fid *fid);
251int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
252int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
253
254struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
255 u64 request_mask);
256
257int p9_client_mknod_dotl(struct p9_fid *oldfid, char *name, int mode,
258 dev_t rdev, kgid_t gid, struct p9_qid *);
259int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
260 kgid_t gid, struct p9_qid *);
261int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
262int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
263struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
264void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
265
266int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
267int p9stat_read(struct p9_client *, char *, int, struct p9_wstat *);
268void p9stat_free(struct p9_wstat *);
269
270int p9_is_proto_dotu(struct p9_client *clnt);
271int p9_is_proto_dotl(struct p9_client *clnt);
272struct p9_fid *p9_client_xattrwalk(struct p9_fid *, const char *, u64 *);
273int p9_client_xattrcreate(struct p9_fid *, const char *, u64, int);
274int p9_client_readlink(struct p9_fid *fid, char **target);
275
276#endif /* NET_9P_CLIENT_H */