--- /dev/null
+/*
+ * include/net/9p/client.h
+ *
+ * 9P Client Definitions
+ *
+ * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ * Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to:
+ * Free Software Foundation
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA 02111-1301 USA
+ *
+ */
+
+#ifndef NET_9P_CLIENT_H
+#define NET_9P_CLIENT_H
+
+#include <linux/utsname.h>
+
+/* Number of requests per row */
+#define P9_ROW_MAXTAG 255
+
+/** enum p9_proto_versions - 9P protocol versions
+ * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
+ * @p9_proto_2000u: 9P2000.u extension
+ * @p9_proto_2000L: 9P2000.L extension
+ */
+
+enum p9_proto_versions{
+ p9_proto_legacy,
+ p9_proto_2000u,
+ p9_proto_2000L,
+};
+
+
+/**
+ * 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,
+ BeginDisconnect,
+ Disconnected,
+ Hung,
+};
+
+/**
+ * enum p9_req_status_t - status of a request
+ * @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_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_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 accommodate
+ * 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;
+ 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
+ * @proto_version: 9P protocol version to use
+ * @trans_mod: module API instantiated with this client
+ * @trans: tranport instance state and API
+ * @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
+ * @name - node name used as client id
+ *
+ * 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 */
+ unsigned int msize;
+ unsigned char proto_version;
+ struct p9_trans_module *trans_mod;
+ enum p9_trans_status status;
+ void *trans;
+
+ struct p9_idpool *fidpool;
+ struct list_head fidlist;
+
+ struct p9_idpool *tagpool;
+ struct p9_req_t *reqs[P9_ROW_MAXTAG];
+ int max_tag;
+
+ char name[__NEW_UTS_LEN + 1];
+};
+
+/**
+ * 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
+ * @rdir: readdir accounting structure (allocated on demand)
+ * @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;
+ int mode;
+ struct p9_qid qid;
+ u32 iounit;
+ kuid_t uid;
+
+ void *rdir;
+
+ struct list_head flist;
+ struct hlist_node dlist; /* list of all fids attached to a dentry */
+};
+
+/**
+ * struct p9_dirent - directory entry structure
+ * @qid: The p9 server qid for this dirent
+ * @d_off: offset to the next dirent
+ * @d_type: type of file
+ * @d_name: file name
+ */
+
+struct p9_dirent {
+ struct p9_qid qid;
+ u64 d_off;
+ unsigned char d_type;
+ char d_name[256];
+};
+
+struct iov_iter;
+
+int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
+int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
+ const char *name);
+int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
+ struct p9_fid *newdirfid, const char *new_name);
+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);
+void p9_client_begin_disconnect(struct p9_client *clnt);
+struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
+ char *uname, kuid_t n_uname, char *aname);
+struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
+ char **wnames, int clone);
+int p9_client_open(struct p9_fid *fid, int mode);
+int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
+ char *extension);
+int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname);
+int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, kgid_t gid,
+ struct p9_qid *qid);
+int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
+ kgid_t gid, struct p9_qid *qid);
+int p9_client_clunk(struct p9_fid *fid);
+int p9_client_fsync(struct p9_fid *fid, int datasync);
+int p9_client_remove(struct p9_fid *fid);
+int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
+int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
+int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
+int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
+int p9dirent_read(struct p9_client *clnt, char *buf, int len,
+ struct p9_dirent *dirent);
+struct p9_wstat *p9_client_stat(struct p9_fid *fid);
+int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
+int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
+
+struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
+ u64 request_mask);
+
+int p9_client_mknod_dotl(struct p9_fid *oldfid, char *name, int mode,
+ dev_t rdev, kgid_t gid, struct p9_qid *);
+int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
+ kgid_t gid, struct p9_qid *);
+int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
+int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
+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 status);
+
+int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
+int p9stat_read(struct p9_client *, char *, int, struct p9_wstat *);
+void p9stat_free(struct p9_wstat *);
+
+int p9_is_proto_dotu(struct p9_client *clnt);
+int p9_is_proto_dotl(struct p9_client *clnt);
+struct p9_fid *p9_client_xattrwalk(struct p9_fid *, const char *, u64 *);
+int p9_client_xattrcreate(struct p9_fid *, const char *, u64, int);
+int p9_client_readlink(struct p9_fid *fid, char **target);
+
+#endif /* NET_9P_CLIENT_H */
Code Review / kvmfornfv.git / blobdiff