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 /* 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 31 enum 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 48 enum 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 65 enum 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 */ 83 struct 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 */ 108 struct 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 */ 144 struct 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 */ 157 struct 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 */ 173 struct 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 */ 201 struct 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 */ 220 struct 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 */ 240 enum fid_source { 241 FID_FROM_OTHER, 242 FID_FROM_INODE, 243 FID_FROM_DENTRY, 244 }; 245 246 struct 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 */ 268 269 struct p9_dirent { 270 struct p9_qid qid; 271 u64 d_off; 272 unsigned char d_type; 273 char d_name[256]; 274 }; 275 276 struct iov_iter; 277 278 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt); 279 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb); 280 int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid, 281 const char *name); 282 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name, 283 struct p9_fid *newdirfid, const char *new_name); 284 struct p9_client *p9_client_create(struct fs_context *fc); 285 void p9_client_destroy(struct p9_client *clnt); 286 void p9_client_disconnect(struct p9_client *clnt); 287 void p9_client_begin_disconnect(struct p9_client *clnt); 288 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid, 289 const char *uname, kuid_t n_uname, const char *aname); 290 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname, 291 const unsigned char * const *wnames, int clone); 292 int p9_client_open(struct p9_fid *fid, int mode); 293 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode, 294 char *extension); 295 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname); 296 int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname, 297 kgid_t gid, struct p9_qid *qid); 298 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode, 299 kgid_t gid, struct p9_qid *qid); 300 int p9_client_clunk(struct p9_fid *fid); 301 int p9_client_fsync(struct p9_fid *fid, int datasync); 302 int p9_client_remove(struct p9_fid *fid); 303 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags); 304 int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err); 305 int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to, 306 int *err); 307 int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err); 308 struct netfs_io_subrequest; 309 void p9_client_write_subreq(struct netfs_io_subrequest *subreq); 310 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset); 311 int p9dirent_read(struct p9_client *clnt, char *buf, int len, 312 struct p9_dirent *dirent); 313 struct p9_wstat *p9_client_stat(struct p9_fid *fid); 314 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst); 315 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr); 316 317 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid, 318 u64 request_mask); 319 320 int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode, 321 dev_t rdev, kgid_t gid, struct p9_qid *qid); 322 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode, 323 kgid_t gid, struct p9_qid *qid); 324 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status); 325 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl); 326 void p9_fcall_fini(struct p9_fcall *fc); 327 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag); 328 329 static inline void p9_req_get(struct p9_req_t *r) 330 { 331 refcount_inc(&r->refcount); 332 } 333 334 static inline int p9_req_try_get(struct p9_req_t *r) 335 { 336 return refcount_inc_not_zero(&r->refcount); 337 } 338 339 int 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 */ 343 DECLARE_TRACEPOINT(9p_fid_ref); 344 void do_trace_9p_fid_get(struct p9_fid *fid); 345 void 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 */ 357 static 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 } 366 367 static 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 } 380 381 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status); 382 383 int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, 384 int16_t *tag, int rewind); 385 int p9stat_read(struct p9_client *clnt, char *buf, int len, 386 struct p9_wstat *st); 387 void p9stat_free(struct p9_wstat *stbuf); 388 389 int p9_is_proto_dotu(struct p9_client *clnt); 390 int p9_is_proto_dotl(struct p9_client *clnt); 391 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid, 392 const char *attr_name, u64 *attr_size); 393 int p9_client_xattrcreate(struct p9_fid *fid, const char *name, 394 u64 attr_size, int flags); 395 int p9_client_readlink(struct p9_fid *fid, char **target); 396 397 int p9_client_init(void); 398 void p9_client_exit(void); 399 400 #endif /* NET_9P_CLIENT_H */ 401