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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/* Number of requests per row */
30#define P9_ROW_MAXTAG 255
31
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_2000L: 9P2000.L extension
36 */
37
38enum p9_proto_versions{
39 p9_proto_legacy,
40 p9_proto_2000u,
41 p9_proto_2000L,
42};
43
44
45/**
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
50 *
51 * This enumeration details the various states a transport
52 * instatiation can be in.
53 */
54
55enum p9_trans_status {
56 Connected,
57 BeginDisconnect,
58 Disconnected,
59 Hung,
60};
61
62/**
63 * enum p9_req_status_t - status of a request
64 * @REQ_STATUS_IDLE: request slot unused
65 * @REQ_STATUS_ALLOC: request has been allocated but not sent
66 * @REQ_STATUS_UNSENT: request waiting to be sent
67 * @REQ_STATUS_SENT: request sent to server
68 * @REQ_STATUS_FLSH: a flush has been sent for this request
69 * @REQ_STATUS_RCVD: response received from server
70 * @REQ_STATUS_FLSHD: request has been flushed
71 * @REQ_STATUS_ERROR: request encountered an error on the client side
72 *
73 * The @REQ_STATUS_IDLE state is used to mark a request slot as unused
74 * but use is actually tracked by the idpool structure which handles tag
75 * id allocation.
76 *
77 */
78
79enum p9_req_status_t {
80 REQ_STATUS_IDLE,
81 REQ_STATUS_ALLOC,
82 REQ_STATUS_UNSENT,
83 REQ_STATUS_SENT,
84 REQ_STATUS_FLSH,
85 REQ_STATUS_RCVD,
86 REQ_STATUS_FLSHD,
87 REQ_STATUS_ERROR,
88};
89
90/**
91 * struct p9_req_t - request slots
92 * @status: status of this request slot
93 * @t_err: transport error
94 * @flush_tag: tag of request being flushed (for flush requests)
95 * @wq: wait_queue for the client to block on for this request
96 * @tc: the request fcall structure
97 * @rc: the response fcall structure
98 * @aux: transport specific data (provided for trans_fd migration)
99 * @req_list: link for higher level objects to chain requests
100 *
101 * Transport use an array to track outstanding requests
102 * instead of a list. While this may incurr overhead during initial
103 * allocation or expansion, it makes request lookup much easier as the
104 * tag id is a index into an array. (We use tag+1 so that we can accommodate
105 * the -1 tag for the T_VERSION request).
106 * This also has the nice effect of only having to allocate wait_queues
107 * once, instead of constantly allocating and freeing them. Its possible
108 * other resources could benefit from this scheme as well.
109 *
110 */
111
112struct p9_req_t {
113 int status;
114 int t_err;
115 wait_queue_head_t *wq;
116 struct p9_fcall *tc;
117 struct p9_fcall *rc;
118 void *aux;
119
120 struct list_head req_list;
121};
122
123/**
124 * struct p9_client - per client instance state
125 * @lock: protect @fidlist
126 * @msize: maximum data size negotiated by protocol
127 * @dotu: extension flags negotiated by protocol
128 * @proto_version: 9P protocol version to use
129 * @trans_mod: module API instantiated with this client
130 * @trans: tranport instance state and API
131 * @conn: connection state information used by trans_fd
132 * @fidpool: fid handle accounting for session
133 * @fidlist: List of active fid handles
134 * @tagpool - transaction id accounting for session
135 * @reqs - 2D array of requests
136 * @max_tag - current maximum tag id allocated
137 *
138 * The client structure is used to keep track of various per-client
139 * state that has been instantiated.
140 * In order to minimize per-transaction overhead we use a
141 * simple array to lookup requests instead of a hash table
142 * or linked list. In order to support larger number of
143 * transactions, we make this a 2D array, allocating new rows
144 * when we need to grow the total number of the transactions.
145 *
146 * Each row is 256 requests and we'll support up to 256 rows for
147 * a total of 64k concurrent requests per session.
148 *
149 * Bugs: duplicated data and potentially unnecessary elements.
150 */
151
152struct p9_client {
153 spinlock_t lock; /* protect client structure */
154 int msize;
155 unsigned char proto_version;
156 struct p9_trans_module *trans_mod;
157 enum p9_trans_status status;
158 void *trans;
159 struct p9_conn *conn;
160
161 struct p9_idpool *fidpool;
162 struct list_head fidlist;
163
164 struct p9_idpool *tagpool;
165 struct p9_req_t *reqs[P9_ROW_MAXTAG];
166 int max_tag;
167};
168
169/**
170 * struct p9_fid - file system entity handle
171 * @clnt: back pointer to instantiating &p9_client
172 * @fid: numeric identifier for this handle
173 * @mode: current mode of this fid (enum?)
174 * @qid: the &p9_qid server identifier this handle points to
175 * @iounit: the server reported maximum transaction size for this file
176 * @uid: the numeric uid of the local user who owns this handle
177 * @rdir: readdir accounting structure (allocated on demand)
178 * @flist: per-client-instance fid tracking
179 * @dlist: per-dentry fid tracking
180 *
181 * TODO: This needs lots of explanation.
182 */
183
184struct p9_fid {
185 struct p9_client *clnt;
186 u32 fid;
187 int mode;
188 struct p9_qid qid;
189 u32 iounit;
190 uid_t uid;
191
192 void *rdir;
193
194 struct list_head flist;
195 struct list_head dlist; /* list of all fids attached to a dentry */
196};
197
198/**
199 * struct p9_dirent - directory entry structure
200 * @qid: The p9 server qid for this dirent
201 * @d_off: offset to the next dirent
202 * @d_type: type of file
203 * @d_name: file name
204 */
205
206struct p9_dirent {
207 struct p9_qid qid;
208 u64 d_off;
209 unsigned char d_type;
210 char d_name[256];
211};
212
213int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
214int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
215 const char *name);
216int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
217 struct p9_fid *newdirfid, const char *new_name);
218struct p9_client *p9_client_create(const char *dev_name, char *options);
219void p9_client_destroy(struct p9_client *clnt);
220void p9_client_disconnect(struct p9_client *clnt);
221void p9_client_begin_disconnect(struct p9_client *clnt);
222struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
223 char *uname, u32 n_uname, char *aname);
224struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
225 char **wnames, int clone);
226int p9_client_open(struct p9_fid *fid, int mode);
227int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
228 char *extension);
229int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname);
230int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, gid_t gid,
231 struct p9_qid *qid);
232int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
233 gid_t gid, struct p9_qid *qid);
234int p9_client_clunk(struct p9_fid *fid);
235int p9_client_fsync(struct p9_fid *fid, int datasync);
236int p9_client_remove(struct p9_fid *fid);
237int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
238int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
239 u64 offset, u32 count);
240int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
241 u64 offset, u32 count);
242int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
243int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,
244 int proto_version);
245struct p9_wstat *p9_client_stat(struct p9_fid *fid);
246int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
247int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
248
249struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
250 u64 request_mask);
251
252int p9_client_mknod_dotl(struct p9_fid *oldfid, char *name, int mode,
253 dev_t rdev, gid_t gid, struct p9_qid *);
254int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
255 gid_t gid, struct p9_qid *);
256int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
257int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
258struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
259void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
260
261int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
262int p9stat_read(char *, int, struct p9_wstat *, int);
263void p9stat_free(struct p9_wstat *);
264
265int p9_is_proto_dotu(struct p9_client *clnt);
266int p9_is_proto_dotl(struct p9_client *clnt);
267struct p9_fid *p9_client_xattrwalk(struct p9_fid *, const char *, u64 *);
268int p9_client_xattrcreate(struct p9_fid *, const char *, u64, int);
269int p9_client_readlink(struct p9_fid *fid, char **target);
270
271#endif /* NET_9P_CLIENT_H */
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * 9P Client Definitions
4 *
5 * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
7 */
8
9#ifndef NET_9P_CLIENT_H
10#define NET_9P_CLIENT_H
11
12#include <linux/utsname.h>
13#include <linux/idr.h>
14#include <linux/tracepoint-defs.h>
15
16/* Number of requests per row */
17#define P9_ROW_MAXTAG 255
18
19/** enum p9_proto_versions - 9P protocol versions
20 * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
21 * @p9_proto_2000u: 9P2000.u extension
22 * @p9_proto_2000L: 9P2000.L extension
23 */
24
25enum p9_proto_versions {
26 p9_proto_legacy,
27 p9_proto_2000u,
28 p9_proto_2000L,
29};
30
31
32/**
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
37 *
38 * This enumeration details the various states a transport
39 * instatiation can be in.
40 */
41
42enum p9_trans_status {
43 Connected,
44 BeginDisconnect,
45 Disconnected,
46 Hung,
47};
48
49/**
50 * enum p9_req_status_t - status of a request
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_RCVD: response received from server
55 * @REQ_STATUS_FLSHD: request has been flushed
56 * @REQ_STATUS_ERROR: request encountered an error on the client side
57 */
58
59enum p9_req_status_t {
60 REQ_STATUS_ALLOC,
61 REQ_STATUS_UNSENT,
62 REQ_STATUS_SENT,
63 REQ_STATUS_RCVD,
64 REQ_STATUS_FLSHD,
65 REQ_STATUS_ERROR,
66};
67
68/**
69 * struct p9_req_t - request slots
70 * @status: status of this request slot
71 * @t_err: transport error
72 * @wq: wait_queue for the client to block on for this request
73 * @tc: the request fcall structure
74 * @rc: the response fcall structure
75 * @req_list: link for higher level objects to chain requests
76 */
77struct p9_req_t {
78 int status;
79 int t_err;
80 refcount_t refcount;
81 wait_queue_head_t wq;
82 struct p9_fcall tc;
83 struct p9_fcall rc;
84 struct list_head req_list;
85};
86
87/**
88 * struct p9_client - per client instance state
89 * @lock: protect @fids and @reqs
90 * @msize: maximum data size negotiated by protocol
91 * @proto_version: 9P protocol version to use
92 * @trans_mod: module API instantiated with this client
93 * @status: connection state
94 * @trans: tranport instance state and API
95 * @fids: All active FID handles
96 * @reqs: All active requests.
97 * @name: node name used as client id
98 *
99 * The client structure is used to keep track of various per-client
100 * state that has been instantiated.
101 */
102struct p9_client {
103 spinlock_t lock;
104 unsigned int msize;
105 unsigned char proto_version;
106 struct p9_trans_module *trans_mod;
107 enum p9_trans_status status;
108 void *trans;
109 struct kmem_cache *fcall_cache;
110
111 union {
112 struct {
113 int rfd;
114 int wfd;
115 } fd;
116 struct {
117 u16 port;
118 bool privport;
119
120 } tcp;
121 } trans_opts;
122
123 struct idr fids;
124 struct idr reqs;
125
126 char name[__NEW_UTS_LEN + 1];
127};
128
129/**
130 * struct p9_fid - file system entity handle
131 * @clnt: back pointer to instantiating &p9_client
132 * @fid: numeric identifier for this handle
133 * @mode: current mode of this fid (enum?)
134 * @qid: the &p9_qid server identifier this handle points to
135 * @iounit: the server reported maximum transaction size for this file
136 * @uid: the numeric uid of the local user who owns this handle
137 * @rdir: readdir accounting structure (allocated on demand)
138 * @dlist: per-dentry fid tracking
139 *
140 * TODO: This needs lots of explanation.
141 */
142enum fid_source {
143 FID_FROM_OTHER,
144 FID_FROM_INODE,
145 FID_FROM_DENTRY,
146};
147
148struct p9_fid {
149 struct p9_client *clnt;
150 u32 fid;
151 refcount_t count;
152 int mode;
153 struct p9_qid qid;
154 u32 iounit;
155 kuid_t uid;
156
157 void *rdir;
158
159 struct hlist_node dlist; /* list of all fids attached to a dentry */
160 struct hlist_node ilist;
161};
162
163/**
164 * struct p9_dirent - directory entry structure
165 * @qid: The p9 server qid for this dirent
166 * @d_off: offset to the next dirent
167 * @d_type: type of file
168 * @d_name: file name
169 */
170
171struct p9_dirent {
172 struct p9_qid qid;
173 u64 d_off;
174 unsigned char d_type;
175 char d_name[256];
176};
177
178struct iov_iter;
179
180int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
181int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
182int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
183 const char *name);
184int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
185 struct p9_fid *newdirfid, const char *new_name);
186struct p9_client *p9_client_create(const char *dev_name, char *options);
187void p9_client_destroy(struct p9_client *clnt);
188void p9_client_disconnect(struct p9_client *clnt);
189void p9_client_begin_disconnect(struct p9_client *clnt);
190struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
191 const char *uname, kuid_t n_uname, const char *aname);
192struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
193 const unsigned char * const *wnames, int clone);
194int p9_client_open(struct p9_fid *fid, int mode);
195int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
196 char *extension);
197int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
198int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
199 kgid_t gid, struct p9_qid *qid);
200int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
201 kgid_t gid, struct p9_qid *qid);
202int p9_client_clunk(struct p9_fid *fid);
203int p9_client_fsync(struct p9_fid *fid, int datasync);
204int p9_client_remove(struct p9_fid *fid);
205int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
206int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
207int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
208 int *err);
209int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
210struct netfs_io_subrequest;
211void p9_client_write_subreq(struct netfs_io_subrequest *subreq);
212int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
213int p9dirent_read(struct p9_client *clnt, char *buf, int len,
214 struct p9_dirent *dirent);
215struct p9_wstat *p9_client_stat(struct p9_fid *fid);
216int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
217int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
218
219struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
220 u64 request_mask);
221
222int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode,
223 dev_t rdev, kgid_t gid, struct p9_qid *qid);
224int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
225 kgid_t gid, struct p9_qid *qid);
226int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
227int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
228void p9_fcall_fini(struct p9_fcall *fc);
229struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag);
230
231static inline void p9_req_get(struct p9_req_t *r)
232{
233 refcount_inc(&r->refcount);
234}
235
236static inline int p9_req_try_get(struct p9_req_t *r)
237{
238 return refcount_inc_not_zero(&r->refcount);
239}
240
241int p9_req_put(struct p9_client *c, struct p9_req_t *r);
242
243/* We cannot have the real tracepoints in header files,
244 * use a wrapper function */
245DECLARE_TRACEPOINT(9p_fid_ref);
246void do_trace_9p_fid_get(struct p9_fid *fid);
247void do_trace_9p_fid_put(struct p9_fid *fid);
248
249/* fid reference counting helpers:
250 * - fids used for any length of time should always be referenced through
251 * p9_fid_get(), and released with p9_fid_put()
252 * - v9fs_fid_lookup() or similar will automatically call get for you
253 * and also require a put
254 * - the *_fid_add() helpers will stash the fid in the inode,
255 * at which point it is the responsibility of evict_inode()
256 * to call the put
257 * - the last put will automatically send a clunk to the server
258 */
259static inline struct p9_fid *p9_fid_get(struct p9_fid *fid)
260{
261 if (tracepoint_enabled(9p_fid_ref))
262 do_trace_9p_fid_get(fid);
263
264 refcount_inc(&fid->count);
265
266 return fid;
267}
268
269static inline int p9_fid_put(struct p9_fid *fid)
270{
271 if (!fid || IS_ERR(fid))
272 return 0;
273
274 if (tracepoint_enabled(9p_fid_ref))
275 do_trace_9p_fid_put(fid);
276
277 if (!refcount_dec_and_test(&fid->count))
278 return 0;
279
280 return p9_client_clunk(fid);
281}
282
283void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
284
285int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type,
286 int16_t *tag, int rewind);
287int p9stat_read(struct p9_client *clnt, char *buf, int len,
288 struct p9_wstat *st);
289void p9stat_free(struct p9_wstat *stbuf);
290
291int p9_is_proto_dotu(struct p9_client *clnt);
292int p9_is_proto_dotl(struct p9_client *clnt);
293struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
294 const char *attr_name, u64 *attr_size);
295int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
296 u64 attr_size, int flags);
297int p9_client_readlink(struct p9_fid *fid, char **target);
298
299int p9_client_init(void);
300void p9_client_exit(void);
301
302#endif /* NET_9P_CLIENT_H */