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 /** 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 Disconnected, 45 Hung, 46 }; 47 48 /** 49 * enum p9_req_status_t - virtio request status 50 * @REQ_STATUS_IDLE: request slot unused 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_FLSH: a flush has been sent for this request 55 * @REQ_STATUS_RCVD: response received from server 56 * @REQ_STATUS_FLSHD: request has been flushed 57 * @REQ_STATUS_ERROR: request encountered an error on the client side 58 * 59 * The @REQ_STATUS_IDLE state is used to mark a request slot as unused 60 * but use is actually tracked by the idpool structure which handles tag 61 * id allocation. 62 * 63 */ 64 65 enum p9_req_status_t { 66 REQ_STATUS_IDLE, 67 REQ_STATUS_ALLOC, 68 REQ_STATUS_UNSENT, 69 REQ_STATUS_SENT, 70 REQ_STATUS_FLSH, 71 REQ_STATUS_RCVD, 72 REQ_STATUS_FLSHD, 73 REQ_STATUS_ERROR, 74 }; 75 76 /** 77 * struct p9_req_t - request slots 78 * @status: status of this request slot 79 * @t_err: transport error 80 * @flush_tag: tag of request being flushed (for flush requests) 81 * @wq: wait_queue for the client to block on for this request 82 * @tc: the request fcall structure 83 * @rc: the response fcall structure 84 * @aux: transport specific data (provided for trans_fd migration) 85 * @req_list: link for higher level objects to chain requests 86 * 87 * Transport use an array to track outstanding requests 88 * instead of a list. While this may incurr overhead during initial 89 * allocation or expansion, it makes request lookup much easier as the 90 * tag id is a index into an array. (We use tag+1 so that we can accomodate 91 * the -1 tag for the T_VERSION request). 92 * This also has the nice effect of only having to allocate wait_queues 93 * once, instead of constantly allocating and freeing them. Its possible 94 * other resources could benefit from this scheme as well. 95 * 96 */ 97 98 struct p9_req_t { 99 int status; 100 int t_err; 101 u16 flush_tag; 102 wait_queue_head_t *wq; 103 struct p9_fcall *tc; 104 struct p9_fcall *rc; 105 void *aux; 106 107 struct list_head req_list; 108 }; 109 110 /** 111 * struct p9_client - per client instance state 112 * @lock: protect @fidlist 113 * @msize: maximum data size negotiated by protocol 114 * @dotu: extension flags negotiated by protocol 115 * @trans_mod: module API instantiated with this client 116 * @trans: tranport instance state and API 117 * @conn: connection state information used by trans_fd 118 * @fidpool: fid handle accounting for session 119 * @fidlist: List of active fid handles 120 * @tagpool - transaction id accounting for session 121 * @reqs - 2D array of requests 122 * @max_tag - current maximum tag id allocated 123 * 124 * The client structure is used to keep track of various per-client 125 * state that has been instantiated. 126 * In order to minimize per-transaction overhead we use a 127 * simple array to lookup requests instead of a hash table 128 * or linked list. In order to support larger number of 129 * transactions, we make this a 2D array, allocating new rows 130 * when we need to grow the total number of the transactions. 131 * 132 * Each row is 256 requests and we'll support up to 256 rows for 133 * a total of 64k concurrent requests per session. 134 * 135 * Bugs: duplicated data and potentially unnecessary elements. 136 */ 137 138 struct p9_client { 139 spinlock_t lock; /* protect client structure */ 140 int msize; 141 unsigned char dotu; 142 struct p9_trans_module *trans_mod; 143 enum p9_trans_status status; 144 void *trans; 145 struct p9_conn *conn; 146 147 struct p9_idpool *fidpool; 148 struct list_head fidlist; 149 150 struct p9_idpool *tagpool; 151 struct p9_req_t *reqs[P9_ROW_MAXTAG]; 152 int max_tag; 153 }; 154 155 /** 156 * struct p9_fid - file system entity handle 157 * @clnt: back pointer to instantiating &p9_client 158 * @fid: numeric identifier for this handle 159 * @mode: current mode of this fid (enum?) 160 * @qid: the &p9_qid server identifier this handle points to 161 * @iounit: the server reported maximum transaction size for this file 162 * @uid: the numeric uid of the local user who owns this handle 163 * @aux: transport specific information (unused?) 164 * @rdir_fpos: tracks offset of file position when reading directory contents 165 * @flist: per-client-instance fid tracking 166 * @dlist: per-dentry fid tracking 167 * 168 * TODO: This needs lots of explanation. 169 */ 170 171 struct p9_fid { 172 struct p9_client *clnt; 173 u32 fid; 174 int mode; 175 struct p9_qid qid; 176 u32 iounit; 177 uid_t uid; 178 void *aux; 179 180 int rdir_fpos; 181 struct list_head flist; 182 struct list_head dlist; /* list of all fids attached to a dentry */ 183 }; 184 185 int p9_client_version(struct p9_client *); 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 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid, 190 char *uname, u32 n_uname, char *aname); 191 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname, 192 u32 n_uname, char *aname); 193 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames, 194 int clone); 195 int p9_client_open(struct p9_fid *fid, int mode); 196 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode, 197 char *extension); 198 int p9_client_clunk(struct p9_fid *fid); 199 int p9_client_remove(struct p9_fid *fid); 200 int p9_client_read(struct p9_fid *fid, char *data, char __user *udata, 201 u64 offset, u32 count); 202 int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata, 203 u64 offset, u32 count); 204 struct p9_wstat *p9_client_stat(struct p9_fid *fid); 205 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst); 206 207 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16); 208 void p9_client_cb(struct p9_client *c, struct p9_req_t *req); 209 210 int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int); 211 int p9stat_read(char *, int, struct p9_wstat *, int); 212 void p9stat_free(struct p9_wstat *); 213 214 215 #endif /* NET_9P_CLIENT_H */ 216