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 40 enum 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 57 enum 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_RCVD: response received from server 71 * @REQ_STATUS_FLSHD: request has been flushed 72 * @REQ_STATUS_ERROR: request encountered an error on the client side 73 * 74 * The @REQ_STATUS_IDLE state is used to mark a request slot as unused 75 * but use is actually tracked by the idpool structure which handles tag 76 * id allocation. 77 * 78 */ 79 80 enum p9_req_status_t { 81 REQ_STATUS_IDLE, 82 REQ_STATUS_ALLOC, 83 REQ_STATUS_UNSENT, 84 REQ_STATUS_SENT, 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 */ 111 112 struct 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 * @fidpool: fid handle accounting for session 132 * @fidlist: List of active fid handles 133 * @tagpool - transaction id accounting for session 134 * @reqs - 2D array of requests 135 * @max_tag - current maximum tag id allocated 136 * @name - node name used as client id 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 */ 151 152 struct p9_client { 153 spinlock_t lock; /* protect client structure */ 154 unsigned int msize; 155 unsigned char proto_version; 156 struct p9_trans_module *trans_mod; 157 enum p9_trans_status status; 158 void *trans; 159 160 struct p9_idpool *fidpool; 161 struct list_head fidlist; 162 163 struct p9_idpool *tagpool; 164 struct p9_req_t *reqs[P9_ROW_MAXTAG]; 165 int max_tag; 166 167 char name[__NEW_UTS_LEN + 1]; 168 }; 169 170 /** 171 * struct p9_fid - file system entity handle 172 * @clnt: back pointer to instantiating &p9_client 173 * @fid: numeric identifier for this handle 174 * @mode: current mode of this fid (enum?) 175 * @qid: the &p9_qid server identifier this handle points to 176 * @iounit: the server reported maximum transaction size for this file 177 * @uid: the numeric uid of the local user who owns this handle 178 * @rdir: readdir accounting structure (allocated on demand) 179 * @flist: per-client-instance fid tracking 180 * @dlist: per-dentry fid tracking 181 * 182 * TODO: This needs lots of explanation. 183 */ 184 185 struct p9_fid { 186 struct p9_client *clnt; 187 u32 fid; 188 int mode; 189 struct p9_qid qid; 190 u32 iounit; 191 kuid_t uid; 192 193 void *rdir; 194 195 struct list_head flist; 196 struct hlist_node dlist; /* list of all fids attached to a dentry */ 197 }; 198 199 /** 200 * struct p9_dirent - directory entry structure 201 * @qid: The p9 server qid for this dirent 202 * @d_off: offset to the next dirent 203 * @d_type: type of file 204 * @d_name: file name 205 */ 206 207 struct p9_dirent { 208 struct p9_qid qid; 209 u64 d_off; 210 unsigned char d_type; 211 char d_name[256]; 212 }; 213 214 struct iov_iter; 215 216 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb); 217 int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid, 218 const char *name); 219 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name, 220 struct p9_fid *newdirfid, const char *new_name); 221 struct p9_client *p9_client_create(const char *dev_name, char *options); 222 void p9_client_destroy(struct p9_client *clnt); 223 void p9_client_disconnect(struct p9_client *clnt); 224 void p9_client_begin_disconnect(struct p9_client *clnt); 225 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid, 226 char *uname, kuid_t n_uname, char *aname); 227 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname, 228 char **wnames, int clone); 229 int p9_client_open(struct p9_fid *fid, int mode); 230 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode, 231 char *extension); 232 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname); 233 int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, kgid_t gid, 234 struct p9_qid *qid); 235 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode, 236 kgid_t gid, struct p9_qid *qid); 237 int p9_client_clunk(struct p9_fid *fid); 238 int p9_client_fsync(struct p9_fid *fid, int datasync); 239 int p9_client_remove(struct p9_fid *fid); 240 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags); 241 int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err); 242 int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err); 243 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset); 244 int p9dirent_read(struct p9_client *clnt, char *buf, int len, 245 struct p9_dirent *dirent); 246 struct p9_wstat *p9_client_stat(struct p9_fid *fid); 247 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst); 248 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr); 249 250 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid, 251 u64 request_mask); 252 253 int p9_client_mknod_dotl(struct p9_fid *oldfid, char *name, int mode, 254 dev_t rdev, kgid_t gid, struct p9_qid *); 255 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode, 256 kgid_t gid, struct p9_qid *); 257 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status); 258 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl); 259 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16); 260 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status); 261 262 int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int); 263 int p9stat_read(struct p9_client *, char *, int, struct p9_wstat *); 264 void p9stat_free(struct p9_wstat *); 265 266 int p9_is_proto_dotu(struct p9_client *clnt); 267 int p9_is_proto_dotl(struct p9_client *clnt); 268 struct p9_fid *p9_client_xattrwalk(struct p9_fid *, const char *, u64 *); 269 int p9_client_xattrcreate(struct p9_fid *, const char *, u64, int); 270 int p9_client_readlink(struct p9_fid *fid, char **target); 271 272 #endif /* NET_9P_CLIENT_H */ 273