X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=include%2Fnet%2F9p%2Fclient.h;h=1f17f3d93727ee4873e3c7c8a7c61c8cdcbb0204;hb=60b8267338aafde5315fc65ff385f3d4d75eccfe;hp=9b9221a213920a8d18504b82559d050cb732742d;hpb=81f8320f624a785d77443ace83391d0fdee695f6;p=linux-2.6-omap-h63xx.git diff --git a/include/net/9p/client.h b/include/net/9p/client.h index 9b9221a2139..1f17f3d9372 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -3,6 +3,7 @@ * * 9P Client Definitions * + * Copyright (C) 2008 by Eric Van Hensbergen * Copyright (C) 2007 by Latchesar Ionkov * * This program is free software; you can redistribute it and/or modify @@ -25,17 +26,148 @@ #ifndef NET_9P_CLIENT_H #define NET_9P_CLIENT_H +/* Number of requests per row */ +#define P9_ROW_MAXTAG 255 + +/** + * enum p9_trans_status - different states of underlying transports + * @Connected: transport is connected and healthy + * @Disconnected: transport has been disconnected + * @Hung: transport is connected by wedged + * + * This enumeration details the various states a transport + * instatiation can be in. + */ + +enum p9_trans_status { + Connected, + Disconnected, + Hung, +}; + +/** + * enum p9_req_status_t - virtio request status + * @REQ_STATUS_IDLE: request slot unused + * @REQ_STATUS_ALLOC: request has been allocated but not sent + * @REQ_STATUS_UNSENT: request waiting to be sent + * @REQ_STATUS_SENT: request sent to server + * @REQ_STATUS_FLSH: a flush has been sent for this request + * @REQ_STATUS_RCVD: response received from server + * @REQ_STATUS_FLSHD: request has been flushed + * @REQ_STATUS_ERROR: request encountered an error on the client side + * + * The @REQ_STATUS_IDLE state is used to mark a request slot as unused + * but use is actually tracked by the idpool structure which handles tag + * id allocation. + * + */ + +enum p9_req_status_t { + REQ_STATUS_IDLE, + REQ_STATUS_ALLOC, + REQ_STATUS_UNSENT, + REQ_STATUS_SENT, + REQ_STATUS_FLSH, + REQ_STATUS_RCVD, + REQ_STATUS_FLSHD, + REQ_STATUS_ERROR, +}; + +/** + * struct p9_req_t - request slots + * @status: status of this request slot + * @t_err: transport error + * @flush_tag: tag of request being flushed (for flush requests) + * @wq: wait_queue for the client to block on for this request + * @tc: the request fcall structure + * @rc: the response fcall structure + * @aux: transport specific data (provided for trans_fd migration) + * @req_list: link for higher level objects to chain requests + * + * Transport use an array to track outstanding requests + * instead of a list. While this may incurr overhead during initial + * allocation or expansion, it makes request lookup much easier as the + * tag id is a index into an array. (We use tag+1 so that we can accomodate + * the -1 tag for the T_VERSION request). + * This also has the nice effect of only having to allocate wait_queues + * once, instead of constantly allocating and freeing them. Its possible + * other resources could benefit from this scheme as well. + * + */ + +struct p9_req_t { + int status; + int t_err; + u16 flush_tag; + wait_queue_head_t *wq; + struct p9_fcall *tc; + struct p9_fcall *rc; + void *aux; + + struct list_head req_list; +}; + +/** + * struct p9_client - per client instance state + * @lock: protect @fidlist + * @msize: maximum data size negotiated by protocol + * @dotu: extension flags negotiated by protocol + * @trans_mod: module API instantiated with this client + * @trans: tranport instance state and API + * @conn: connection state information used by trans_fd + * @fidpool: fid handle accounting for session + * @fidlist: List of active fid handles + * @tagpool - transaction id accounting for session + * @reqs - 2D array of requests + * @max_tag - current maximum tag id allocated + * + * The client structure is used to keep track of various per-client + * state that has been instantiated. + * In order to minimize per-transaction overhead we use a + * simple array to lookup requests instead of a hash table + * or linked list. In order to support larger number of + * transactions, we make this a 2D array, allocating new rows + * when we need to grow the total number of the transactions. + * + * Each row is 256 requests and we'll support up to 256 rows for + * a total of 64k concurrent requests per session. + * + * Bugs: duplicated data and potentially unnecessary elements. + */ + struct p9_client { spinlock_t lock; /* protect client structure */ int msize; unsigned char dotu; - struct p9_trans *trans; + struct p9_trans_module *trans_mod; + enum p9_trans_status status; + void *trans; struct p9_conn *conn; struct p9_idpool *fidpool; struct list_head fidlist; + + struct p9_idpool *tagpool; + struct p9_req_t *reqs[P9_ROW_MAXTAG]; + int max_tag; }; +/** + * struct p9_fid - file system entity handle + * @clnt: back pointer to instantiating &p9_client + * @fid: numeric identifier for this handle + * @mode: current mode of this fid (enum?) + * @qid: the &p9_qid server identifier this handle points to + * @iounit: the server reported maximum transaction size for this file + * @uid: the numeric uid of the local user who owns this handle + * @aux: transport specific information (unused?) + * @rdir_fpos: tracks offset of file position when reading directory contents + * @flist: per-client-instance fid tracking + * @dlist: per-dentry fid tracking + * + * TODO: This needs lots of explanation. + */ + struct p9_fid { struct p9_client *clnt; u32 fid; @@ -46,14 +178,11 @@ struct p9_fid { void *aux; int rdir_fpos; - int rdir_pos; - struct p9_fcall *rdir_fcall; struct list_head flist; struct list_head dlist; /* list of all fids attached to a dentry */ }; -struct p9_client *p9_client_create(struct p9_trans *trans, int msize, - int dotu); +struct p9_client *p9_client_create(const char *dev_name, char *options); void p9_client_destroy(struct p9_client *clnt); void p9_client_disconnect(struct p9_client *clnt); struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid, @@ -67,15 +196,18 @@ int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode, char *extension); int p9_client_clunk(struct p9_fid *fid); int p9_client_remove(struct p9_fid *fid); -int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count); -int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count); -int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count); -int p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset, - u32 count); -int p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset, - u32 count); -struct p9_stat *p9_client_stat(struct p9_fid *fid); +int p9_client_read(struct p9_fid *fid, char *data, char __user *udata, + u64 offset, u32 count); +int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata, + u64 offset, u32 count); +struct p9_wstat *p9_client_stat(struct p9_fid *fid); int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst); -struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset); + +struct p9_req_t *p9_tag_lookup(struct p9_client *, u16); +void p9_client_cb(struct p9_client *c, struct p9_req_t *req); + +int p9stat_read(char *, int, struct p9_wstat *, int); +void p9stat_free(struct p9_wstat *); + #endif /* NET_9P_CLIENT_H */