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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * 9P Client Definitions
4 *
5 * Copyright (C) 2008 by Eric Van Hensbergen <[email protected]>
6 * Copyright (C) 2007 by Latchesar Ionkov <[email protected]>
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/* DEFAULT MSIZE = 32 pages worth of payload + P9_HDRSZ +
20 * room for write (16 extra) or read (11 extra) operands.
21 */
22
23#define DEFAULT_MSIZE ((128 * 1024) + P9_IOHDRSZ)
24
25/** enum p9_proto_versions - 9P protocol versions
26 * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
27 * @p9_proto_2000u: 9P2000.u extension
28 * @p9_proto_2000L: 9P2000.L extension
29 */
30
31enum p9_proto_versions {
32 p9_proto_legacy,
33 p9_proto_2000u,
34 p9_proto_2000L,
35};
36
37
38/**
39 * enum p9_trans_status - different states of underlying transports
40 * @Connected: transport is connected and healthy
41 * @Disconnected: transport has been disconnected
42 * @Hung: transport is connected by wedged
43 *
44 * This enumeration details the various states a transport
45 * instatiation can be in.
46 */
47
48enum p9_trans_status {
49 Connected,
50 BeginDisconnect,
51 Disconnected,
52 Hung,
53};
54
55/**
56 * enum p9_req_status_t - status of a request
57 * @REQ_STATUS_ALLOC: request has been allocated but not sent
58 * @REQ_STATUS_UNSENT: request waiting to be sent
59 * @REQ_STATUS_SENT: request sent to server
60 * @REQ_STATUS_RCVD: response received from server
61 * @REQ_STATUS_FLSHD: request has been flushed
62 * @REQ_STATUS_ERROR: request encountered an error on the client side
63 */
64
65enum p9_req_status_t {
66 REQ_STATUS_ALLOC,
67 REQ_STATUS_UNSENT,
68 REQ_STATUS_SENT,
69 REQ_STATUS_RCVD,
70 REQ_STATUS_FLSHD,
71 REQ_STATUS_ERROR,
72};
73
74/**
75 * struct p9_req_t - request slots
76 * @status: status of this request slot
77 * @t_err: transport error
78 * @wq: wait_queue for the client to block on for this request
79 * @tc: the request fcall structure
80 * @rc: the response fcall structure
81 * @req_list: link for higher level objects to chain requests
82 */
83struct p9_req_t {
84 int status;
85 int t_err;
86 refcount_t refcount;
87 wait_queue_head_t wq;
88 struct p9_fcall tc;
89 struct p9_fcall rc;
90 struct list_head req_list;
91};
92
93/**
94 * struct p9_client - per client instance state
95 * @lock: protect @fids and @reqs
96 * @msize: maximum data size negotiated by protocol
97 * @proto_version: 9P protocol version to use
98 * @trans_mod: module API instantiated with this client
99 * @status: connection state
100 * @trans: tranport instance state and API
101 * @fids: All active FID handles
102 * @reqs: All active requests.
103 * @name: node name used as client id
104 *
105 * The client structure is used to keep track of various per-client
106 * state that has been instantiated.
107 */
108struct p9_client {
109 spinlock_t lock;
110 unsigned int msize;
111 unsigned char proto_version;
112 struct p9_trans_module *trans_mod;
113 enum p9_trans_status status;
114 void *trans;
115 struct kmem_cache *fcall_cache;
116
117 union {
118 struct {
119 int rfd;
120 int wfd;
121 } fd;
122 struct {
123 u16 port;
124 bool privport;
125
126 } tcp;
127 } trans_opts;
128
129 struct idr fids;
130 struct idr reqs;
131
132 char name[__NEW_UTS_LEN + 1];
133};
134
135/**
136 * struct p9_fd_opts - holds client options during parsing
137 * @msize: maximum data size negotiated by protocol
138 * @prot-Oversion: 9P protocol version to use
139 * @trans_mod: module API instantiated with this client
140 *
141 * These parsed options get transferred into client in
142 * apply_client_options()
143 */
144struct p9_client_opts {
145 unsigned int msize;
146 unsigned char proto_version;
147 struct p9_trans_module *trans_mod;
148};
149
150/**
151 * struct p9_fd_opts - per-transport options for fd transport
152 * @rfd: file descriptor for reading (trans=fd)
153 * @wfd: file descriptor for writing (trans=fd)
154 * @port: port to connect to (trans=tcp)
155 * @privport: port is privileged
156 */
157struct p9_fd_opts {
158 int rfd;
159 int wfd;
160 u16 port;
161 bool privport;
162};
163
164/**
165 * struct p9_rdma_opts - Collection of mount options for rdma transport
166 * @port: port of connection
167 * @privport: Whether a privileged port may be used
168 * @sq_depth: The requested depth of the SQ. This really doesn't need
169 * to be any deeper than the number of threads used in the client
170 * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
171 * @timeout: Time to wait in msecs for CM events
172 */
173struct p9_rdma_opts {
174 short port;
175 bool privport;
176 int sq_depth;
177 int rq_depth;
178 long timeout;
179};
180
181/**
182 * struct p9_session_opts - holds parsed options for v9fs_session_info
183 * @flags: session options of type &p9_session_flags
184 * @nodev: set to 1 to disable device mapping
185 * @debug: debug level
186 * @afid: authentication handle
187 * @cache: cache mode of type &p9_cache_bits
188 * @cachetag: the tag of the cache associated with this session
189 * @uname: string user name to mount hierarchy as
190 * @aname: mount specifier for remote hierarchy
191 * @dfltuid: default numeric userid to mount hierarchy as
192 * @dfltgid: default numeric groupid to mount hierarchy as
193 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
194 * @session_lock_timeout: retry interval for blocking locks
195 * @ndentry_timeout_ms: Negative dentry lookup cache retention time in ms
196 *
197 * This strucure holds options which are parsed and will be transferred
198 * to the v9fs_session_info structure when mounted, and therefore largely
199 * duplicates struct v9fs_session_info.
200 */
201struct p9_session_opts {
202 unsigned int flags;
203 unsigned char nodev;
204 unsigned short debug;
205 unsigned int afid;
206 unsigned int cache;
207 unsigned int ndentry_timeout_ms;
208#ifdef CONFIG_9P_FSCACHE
209 char *cachetag;
210#endif
211 char *uname;
212 char *aname;
213 kuid_t dfltuid;
214 kgid_t dfltgid;
215 kuid_t uid;
216 long session_lock_timeout;
217};
218
219/* Used by mount API to store parsed mount options */
220struct v9fs_context {
221 struct p9_client_opts client_opts;
222 struct p9_fd_opts fd_opts;
223 struct p9_rdma_opts rdma_opts;
224 struct p9_session_opts session_opts;
225};
226
227/**
228 * struct p9_fid - file system entity handle
229 * @clnt: back pointer to instantiating &p9_client
230 * @fid: numeric identifier for this handle
231 * @mode: current mode of this fid (enum?)
232 * @qid: the &p9_qid server identifier this handle points to
233 * @iounit: the server reported maximum transaction size for this file
234 * @uid: the numeric uid of the local user who owns this handle
235 * @rdir: readdir accounting structure (allocated on demand)
236 * @dlist: per-dentry fid tracking
237 *
238 * TODO: This needs lots of explanation.
239 */
240enum fid_source {
241 FID_FROM_OTHER,
242 FID_FROM_INODE,
243 FID_FROM_DENTRY,
244};
245
246struct p9_fid {
247 struct p9_client *clnt;
248 u32 fid;
249 refcount_t count;
250 int mode;
251 struct p9_qid qid;
252 u32 iounit;
253 kuid_t uid;
254
255 void *rdir;
256
257 struct hlist_node dlist; /* list of all fids attached to a dentry */
258 struct hlist_node ilist;
259};
260
261/**
262 * struct p9_dirent - directory entry structure
263 * @qid: The p9 server qid for this dirent
264 * @d_off: offset to the next dirent
265 * @d_type: type of file
266 * @d_name: file name
267 */
268
269struct p9_dirent {
270 struct p9_qid qid;
271 u64 d_off;
272 unsigned char d_type;
273 char d_name[256];
274};
275
276struct iov_iter;
277
278int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
279int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
280int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
281 const char *name);
282int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
283 struct p9_fid *newdirfid, const char *new_name);
284struct p9_client *p9_client_create(struct fs_context *fc);
285void p9_client_destroy(struct p9_client *clnt);
286void p9_client_disconnect(struct p9_client *clnt);
287void p9_client_begin_disconnect(struct p9_client *clnt);
288struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
289 const char *uname, kuid_t n_uname, const char *aname);
290struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
291 const unsigned char * const *wnames, int clone);
292int p9_client_open(struct p9_fid *fid, int mode);
293int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
294 char *extension);
295int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
296int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
297 kgid_t gid, struct p9_qid *qid);
298int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
299 kgid_t gid, struct p9_qid *qid);
300int p9_client_clunk(struct p9_fid *fid);
301int p9_client_fsync(struct p9_fid *fid, int datasync);
302int p9_client_remove(struct p9_fid *fid);
303int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
304int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
305int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
306 int *err);
307int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
308struct netfs_io_subrequest;
309void p9_client_write_subreq(struct netfs_io_subrequest *subreq);
310int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
311int p9dirent_read(struct p9_client *clnt, char *buf, int len,
312 struct p9_dirent *dirent);
313struct p9_wstat *p9_client_stat(struct p9_fid *fid);
314int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
315int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
316
317struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
318 u64 request_mask);
319
320int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode,
321 dev_t rdev, kgid_t gid, struct p9_qid *qid);
322int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
323 kgid_t gid, struct p9_qid *qid);
324int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
325int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
326void p9_fcall_fini(struct p9_fcall *fc);
327struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag);
328
329static inline void p9_req_get(struct p9_req_t *r)
330{
331 refcount_inc(&r->refcount);
332}
333
334static inline int p9_req_try_get(struct p9_req_t *r)
335{
336 return refcount_inc_not_zero(&r->refcount);
337}
338
339int p9_req_put(struct p9_client *c, struct p9_req_t *r);
340
341/* We cannot have the real tracepoints in header files,
342 * use a wrapper function */
343DECLARE_TRACEPOINT(9p_fid_ref);
344void do_trace_9p_fid_get(struct p9_fid *fid);
345void do_trace_9p_fid_put(struct p9_fid *fid);
346
347/* fid reference counting helpers:
348 * - fids used for any length of time should always be referenced through
349 * p9_fid_get(), and released with p9_fid_put()
350 * - v9fs_fid_lookup() or similar will automatically call get for you
351 * and also require a put
352 * - the *_fid_add() helpers will stash the fid in the inode,
353 * at which point it is the responsibility of evict_inode()
354 * to call the put
355 * - the last put will automatically send a clunk to the server
356 */
357static inline struct p9_fid *p9_fid_get(struct p9_fid *fid)
358{
359 if (tracepoint_enabled(9p_fid_ref))
360 do_trace_9p_fid_get(fid);
361
362 refcount_inc(&fid->count);
363
364 return fid;
365}
366
367static inline int p9_fid_put(struct p9_fid *fid)
368{
369 if (!fid || IS_ERR(fid))
370 return 0;
371
372 if (tracepoint_enabled(9p_fid_ref))
373 do_trace_9p_fid_put(fid);
374
375 if (!refcount_dec_and_test(&fid->count))
376 return 0;
377
378 return p9_client_clunk(fid);
379}
380
381void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
382
383int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type,
384 int16_t *tag, int rewind);
385int p9stat_read(struct p9_client *clnt, char *buf, int len,
386 struct p9_wstat *st);
387void p9stat_free(struct p9_wstat *stbuf);
388
389int p9_is_proto_dotu(struct p9_client *clnt);
390int p9_is_proto_dotl(struct p9_client *clnt);
391struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
392 const char *attr_name, u64 *attr_size);
393int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
394 u64 attr_size, int flags);
395int p9_client_readlink(struct p9_fid *fid, char **target);
396
397int p9_client_init(void);
398void p9_client_exit(void);
399
400#endif /* NET_9P_CLIENT_H */