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 25 enum 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 42 enum 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 59 enum 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 */ 77 struct 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 */ 102 struct 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 */ 142 enum fid_source { 143 FID_FROM_OTHER, 144 FID_FROM_INODE, 145 FID_FROM_DENTRY, 146 }; 147 148 struct 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 */ 170 171 struct p9_dirent { 172 struct p9_qid qid; 173 u64 d_off; 174 unsigned char d_type; 175 char d_name[256]; 176 }; 177 178 struct iov_iter; 179 180 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt); 181 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb); 182 int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid, 183 const char *name); 184 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name, 185 struct p9_fid *newdirfid, const char *new_name); 186 struct p9_client *p9_client_create(const char *dev_name, char *options); 187 void p9_client_destroy(struct p9_client *clnt); 188 void p9_client_disconnect(struct p9_client *clnt); 189 void p9_client_begin_disconnect(struct p9_client *clnt); 190 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid, 191 const char *uname, kuid_t n_uname, const char *aname); 192 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname, 193 const unsigned char * const *wnames, int clone); 194 int p9_client_open(struct p9_fid *fid, int mode); 195 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode, 196 char *extension); 197 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname); 198 int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname, 199 kgid_t gid, struct p9_qid *qid); 200 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode, 201 kgid_t gid, struct p9_qid *qid); 202 int p9_client_clunk(struct p9_fid *fid); 203 int p9_client_fsync(struct p9_fid *fid, int datasync); 204 int p9_client_remove(struct p9_fid *fid); 205 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags); 206 int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err); 207 int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to, 208 int *err); 209 int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err); 210 struct netfs_io_subrequest; 211 void p9_client_write_subreq(struct netfs_io_subrequest *subreq); 212 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset); 213 int p9dirent_read(struct p9_client *clnt, char *buf, int len, 214 struct p9_dirent *dirent); 215 struct p9_wstat *p9_client_stat(struct p9_fid *fid); 216 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst); 217 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr); 218 219 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid, 220 u64 request_mask); 221 222 int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode, 223 dev_t rdev, kgid_t gid, struct p9_qid *qid); 224 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode, 225 kgid_t gid, struct p9_qid *qid); 226 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status); 227 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl); 228 void p9_fcall_fini(struct p9_fcall *fc); 229 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag); 230 231 static inline void p9_req_get(struct p9_req_t *r) 232 { 233 refcount_inc(&r->refcount); 234 } 235 236 static inline int p9_req_try_get(struct p9_req_t *r) 237 { 238 return refcount_inc_not_zero(&r->refcount); 239 } 240 241 int 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 */ 245 DECLARE_TRACEPOINT(9p_fid_ref); 246 void do_trace_9p_fid_get(struct p9_fid *fid); 247 void 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 */ 259 static 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 } 268 269 static 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 } 282 283 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status); 284 285 int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, 286 int16_t *tag, int rewind); 287 int p9stat_read(struct p9_client *clnt, char *buf, int len, 288 struct p9_wstat *st); 289 void p9stat_free(struct p9_wstat *stbuf); 290 291 int p9_is_proto_dotu(struct p9_client *clnt); 292 int p9_is_proto_dotl(struct p9_client *clnt); 293 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid, 294 const char *attr_name, u64 *attr_size); 295 int p9_client_xattrcreate(struct p9_fid *fid, const char *name, 296 u64 attr_size, int flags); 297 int p9_client_readlink(struct p9_fid *fid, char **target); 298 299 int p9_client_init(void); 300 void p9_client_exit(void); 301 302 #endif /* NET_9P_CLIENT_H */ 303