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Diffstat (limited to '')
| -rw-r--r-- | include/net/9p/client.h | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/include/net/9p/client.h b/include/net/9p/client.h new file mode 100644 index 000000000..78ebcf782 --- /dev/null +++ b/include/net/9p/client.h @@ -0,0 +1,300 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * 9P Client Definitions + * + * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com> + * Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net> + */ + +#ifndef NET_9P_CLIENT_H +#define NET_9P_CLIENT_H + +#include <linux/utsname.h> +#include <linux/idr.h> +#include <linux/tracepoint-defs.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_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 + */ + +enum p9_req_status_t { + 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 + * @wq: wait_queue for the client to block on for this request + * @tc: the request fcall structure + * @rc: the response fcall structure + * @req_list: link for higher level objects to chain requests + */ +struct p9_req_t { + int status; + int t_err; + refcount_t refcount; + wait_queue_head_t wq; + struct p9_fcall tc; + struct p9_fcall rc; + struct list_head req_list; +}; + +/** + * struct p9_client - per client instance state + * @lock: protect @fids and @reqs + * @msize: maximum data size negotiated by protocol + * @proto_version: 9P protocol version to use + * @trans_mod: module API instantiated with this client + * @status: connection state + * @trans: tranport instance state and API + * @fids: All active FID handles + * @reqs: All active requests. + * @name: node name used as client id + * + * The client structure is used to keep track of various per-client + * state that has been instantiated. + */ +struct p9_client { + spinlock_t lock; + unsigned int msize; + unsigned char proto_version; + struct p9_trans_module *trans_mod; + enum p9_trans_status status; + void *trans; + struct kmem_cache *fcall_cache; + + union { + struct { + int rfd; + int wfd; + } fd; + struct { + u16 port; + bool privport; + + } tcp; + } trans_opts; + + struct idr fids; + struct idr reqs; + + 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) + * @dlist: per-dentry fid tracking + * + * TODO: This needs lots of explanation. + */ +enum fid_source { + FID_FROM_OTHER, + FID_FROM_INODE, + FID_FROM_DENTRY, +}; + +struct p9_fid { + struct p9_client *clnt; + u32 fid; + refcount_t count; + int mode; + struct p9_qid qid; + u32 iounit; + kuid_t uid; + + void *rdir; + + struct hlist_node dlist; /* list of all fids attached to a dentry */ + struct hlist_node ilist; +}; + +/** + * 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_show_client_options(struct seq_file *m, struct p9_client *clnt); +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, + const char *uname, kuid_t n_uname, const char *aname); +struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname, + const unsigned char * const *wnames, int clone); +int p9_client_open(struct p9_fid *fid, int mode); +int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode, + char *extension); +int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname); +int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname, + kgid_t gid, struct p9_qid *qid); +int p9_client_create_dotl(struct p9_fid *ofid, const 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_read_once(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, const char *name, int mode, + dev_t rdev, kgid_t gid, struct p9_qid *qid); +int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode, + kgid_t gid, struct p9_qid *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); +void p9_fcall_fini(struct p9_fcall *fc); +struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag); + +static inline void p9_req_get(struct p9_req_t *r) +{ + refcount_inc(&r->refcount); +} + +static inline int p9_req_try_get(struct p9_req_t *r) +{ + return refcount_inc_not_zero(&r->refcount); +} + +int p9_req_put(struct p9_client *c, struct p9_req_t *r); + +/* We cannot have the real tracepoints in header files, + * use a wrapper function */ +DECLARE_TRACEPOINT(9p_fid_ref); +void do_trace_9p_fid_get(struct p9_fid *fid); +void do_trace_9p_fid_put(struct p9_fid *fid); + +/* fid reference counting helpers: + * - fids used for any length of time should always be referenced through + * p9_fid_get(), and released with p9_fid_put() + * - v9fs_fid_lookup() or similar will automatically call get for you + * and also require a put + * - the *_fid_add() helpers will stash the fid in the inode, + * at which point it is the responsibility of evict_inode() + * to call the put + * - the last put will automatically send a clunk to the server + */ +static inline struct p9_fid *p9_fid_get(struct p9_fid *fid) +{ + if (tracepoint_enabled(9p_fid_ref)) + do_trace_9p_fid_get(fid); + + refcount_inc(&fid->count); + + return fid; +} + +static inline int p9_fid_put(struct p9_fid *fid) +{ + if (!fid || IS_ERR(fid)) + return 0; + + if (tracepoint_enabled(9p_fid_ref)) + do_trace_9p_fid_put(fid); + + if (!refcount_dec_and_test(&fid->count)) + return 0; + + return p9_client_clunk(fid); +} + +void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status); + +int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, + int16_t *tag, int rewind); +int p9stat_read(struct p9_client *clnt, char *buf, int len, + struct p9_wstat *st); +void p9stat_free(struct p9_wstat *stbuf); + +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 *file_fid, + const char *attr_name, u64 *attr_size); +int p9_client_xattrcreate(struct p9_fid *fid, const char *name, + u64 attr_size, int flags); +int p9_client_readlink(struct p9_fid *fid, char **target); + +int p9_client_init(void); +void p9_client_exit(void); + +#endif /* NET_9P_CLIENT_H */ |