Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 926 insertions, 0 deletions

diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
new file mode 100644
index 000000000..13abe013a
--- /dev/null
+++ b/include/net/9p/9p.h
@@ -0,0 +1,557 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * 9P protocol definitions.
+ *
+ *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ */
+
+#ifndef NET_9P_H
+#define NET_9P_H
+
+/**
+ * enum p9_debug_flags - bits for mount time debug parameter
+ * @P9_DEBUG_ERROR: more verbose error messages including original error string
+ * @P9_DEBUG_9P: 9P protocol tracing
+ * @P9_DEBUG_VFS: VFS API tracing
+ * @P9_DEBUG_CONV: protocol conversion tracing
+ * @P9_DEBUG_MUX: trace management of concurrent transactions
+ * @P9_DEBUG_TRANS: transport tracing
+ * @P9_DEBUG_SLABS: memory management tracing
+ * @P9_DEBUG_FCALL: verbose dump of protocol messages
+ * @P9_DEBUG_FID: fid allocation/deallocation tracking
+ * @P9_DEBUG_PKT: packet marshalling/unmarshalling
+ * @P9_DEBUG_FSC: FS-cache tracing
+ * @P9_DEBUG_VPKT: Verbose packet debugging (full packet dump)
+ *
+ * These flags are passed at mount time to turn on various levels of
+ * verbosity and tracing which will be output to the system logs.
+ */
+
+enum p9_debug_flags {
+	P9_DEBUG_ERROR =	(1<<0),
+	P9_DEBUG_9P =		(1<<2),
+	P9_DEBUG_VFS =		(1<<3),
+	P9_DEBUG_CONV =		(1<<4),
+	P9_DEBUG_MUX =		(1<<5),
+	P9_DEBUG_TRANS =	(1<<6),
+	P9_DEBUG_SLABS =	(1<<7),
+	P9_DEBUG_FCALL =	(1<<8),
+	P9_DEBUG_FID =		(1<<9),
+	P9_DEBUG_PKT =		(1<<10),
+	P9_DEBUG_FSC =		(1<<11),
+	P9_DEBUG_VPKT =		(1<<12),
+};
+
+#ifdef CONFIG_NET_9P_DEBUG
+extern unsigned int p9_debug_level;
+__printf(3, 4)
+void _p9_debug(enum p9_debug_flags level, const char *func,
+	       const char *fmt, ...);
+#define p9_debug(level, fmt, ...)			\
+	_p9_debug(level, __func__, fmt, ##__VA_ARGS__)
+#else
+#define p9_debug(level, fmt, ...)			\
+	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/**
+ * enum p9_msg_t - 9P message types
+ * @P9_TLERROR: not used
+ * @P9_RLERROR: response for any failed request for 9P2000.L
+ * @P9_TSTATFS: file system status request
+ * @P9_RSTATFS: file system status response
+ * @P9_TSYMLINK: make symlink request
+ * @P9_RSYMLINK: make symlink response
+ * @P9_TMKNOD: create a special file object request
+ * @P9_RMKNOD: create a special file object response
+ * @P9_TLCREATE: prepare a handle for I/O on an new file for 9P2000.L
+ * @P9_RLCREATE: response with file access information for 9P2000.L
+ * @P9_TRENAME: rename request
+ * @P9_RRENAME: rename response
+ * @P9_TMKDIR: create a directory request
+ * @P9_RMKDIR: create a directory response
+ * @P9_TVERSION: version handshake request
+ * @P9_RVERSION: version handshake response
+ * @P9_TAUTH: request to establish authentication channel
+ * @P9_RAUTH: response with authentication information
+ * @P9_TATTACH: establish user access to file service
+ * @P9_RATTACH: response with top level handle to file hierarchy
+ * @P9_TERROR: not used
+ * @P9_RERROR: response for any failed request
+ * @P9_TFLUSH: request to abort a previous request
+ * @P9_RFLUSH: response when previous request has been cancelled
+ * @P9_TWALK: descend a directory hierarchy
+ * @P9_RWALK: response with new handle for position within hierarchy
+ * @P9_TOPEN: prepare a handle for I/O on an existing file
+ * @P9_ROPEN: response with file access information
+ * @P9_TCREATE: prepare a handle for I/O on a new file
+ * @P9_RCREATE: response with file access information
+ * @P9_TREAD: request to transfer data from a file or directory
+ * @P9_RREAD: response with data requested
+ * @P9_TWRITE: reuqest to transfer data to a file
+ * @P9_RWRITE: response with out much data was transferred to file
+ * @P9_TCLUNK: forget about a handle to an entity within the file system
+ * @P9_RCLUNK: response when server has forgotten about the handle
+ * @P9_TREMOVE: request to remove an entity from the hierarchy
+ * @P9_RREMOVE: response when server has removed the entity
+ * @P9_TSTAT: request file entity attributes
+ * @P9_RSTAT: response with file entity attributes
+ * @P9_TWSTAT: request to update file entity attributes
+ * @P9_RWSTAT: response when file entity attributes are updated
+ *
+ * There are 14 basic operations in 9P2000, paired as
+ * requests and responses.  The one special case is ERROR
+ * as there is no @P9_TERROR request for clients to transmit to
+ * the server, but the server may respond to any other request
+ * with an @P9_RERROR.
+ *
+ * See Also: http://plan9.bell-labs.com/sys/man/5/INDEX.html
+ */
+
+enum p9_msg_t {
+	P9_TLERROR = 6,
+	P9_RLERROR,
+	P9_TSTATFS = 8,
+	P9_RSTATFS,
+	P9_TLOPEN = 12,
+	P9_RLOPEN,
+	P9_TLCREATE = 14,
+	P9_RLCREATE,
+	P9_TSYMLINK = 16,
+	P9_RSYMLINK,
+	P9_TMKNOD = 18,
+	P9_RMKNOD,
+	P9_TRENAME = 20,
+	P9_RRENAME,
+	P9_TREADLINK = 22,
+	P9_RREADLINK,
+	P9_TGETATTR = 24,
+	P9_RGETATTR,
+	P9_TSETATTR = 26,
+	P9_RSETATTR,
+	P9_TXATTRWALK = 30,
+	P9_RXATTRWALK,
+	P9_TXATTRCREATE = 32,
+	P9_RXATTRCREATE,
+	P9_TREADDIR = 40,
+	P9_RREADDIR,
+	P9_TFSYNC = 50,
+	P9_RFSYNC,
+	P9_TLOCK = 52,
+	P9_RLOCK,
+	P9_TGETLOCK = 54,
+	P9_RGETLOCK,
+	P9_TLINK = 70,
+	P9_RLINK,
+	P9_TMKDIR = 72,
+	P9_RMKDIR,
+	P9_TRENAMEAT = 74,
+	P9_RRENAMEAT,
+	P9_TUNLINKAT = 76,
+	P9_RUNLINKAT,
+	P9_TVERSION = 100,
+	P9_RVERSION,
+	P9_TAUTH = 102,
+	P9_RAUTH,
+	P9_TATTACH = 104,
+	P9_RATTACH,
+	P9_TERROR = 106,
+	P9_RERROR,
+	P9_TFLUSH = 108,
+	P9_RFLUSH,
+	P9_TWALK = 110,
+	P9_RWALK,
+	P9_TOPEN = 112,
+	P9_ROPEN,
+	P9_TCREATE = 114,
+	P9_RCREATE,
+	P9_TREAD = 116,
+	P9_RREAD,
+	P9_TWRITE = 118,
+	P9_RWRITE,
+	P9_TCLUNK = 120,
+	P9_RCLUNK,
+	P9_TREMOVE = 122,
+	P9_RREMOVE,
+	P9_TSTAT = 124,
+	P9_RSTAT,
+	P9_TWSTAT = 126,
+	P9_RWSTAT,
+};
+
+/**
+ * enum p9_open_mode_t - 9P open modes
+ * @P9_OREAD: open file for reading only
+ * @P9_OWRITE: open file for writing only
+ * @P9_ORDWR: open file for reading or writing
+ * @P9_OEXEC: open file for execution
+ * @P9_OTRUNC: truncate file to zero-length before opening it
+ * @P9_OREXEC: close the file when an exec(2) system call is made
+ * @P9_ORCLOSE: remove the file when the file is closed
+ * @P9_OAPPEND: open the file and seek to the end
+ * @P9_OEXCL: only create a file, do not open it
+ *
+ * 9P open modes differ slightly from Posix standard modes.
+ * In particular, there are extra modes which specify different
+ * semantic behaviors than may be available on standard Posix
+ * systems.  For example, @P9_OREXEC and @P9_ORCLOSE are modes that
+ * most likely will not be issued from the Linux VFS client, but may
+ * be supported by servers.
+ *
+ * See Also: http://plan9.bell-labs.com/magic/man2html/2/open
+ */
+
+enum p9_open_mode_t {
+	P9_OREAD = 0x00,
+	P9_OWRITE = 0x01,
+	P9_ORDWR = 0x02,
+	P9_OEXEC = 0x03,
+	P9_OTRUNC = 0x10,
+	P9_OREXEC = 0x20,
+	P9_ORCLOSE = 0x40,
+	P9_OAPPEND = 0x80,
+	P9_OEXCL = 0x1000,
+};
+
+/**
+ * enum p9_perm_t - 9P permissions
+ * @P9_DMDIR: mode bit for directories
+ * @P9_DMAPPEND: mode bit for is append-only
+ * @P9_DMEXCL: mode bit for excluse use (only one open handle allowed)
+ * @P9_DMMOUNT: mode bit for mount points
+ * @P9_DMAUTH: mode bit for authentication file
+ * @P9_DMTMP: mode bit for non-backed-up files
+ * @P9_DMSYMLINK: mode bit for symbolic links (9P2000.u)
+ * @P9_DMLINK: mode bit for hard-link (9P2000.u)
+ * @P9_DMDEVICE: mode bit for device files (9P2000.u)
+ * @P9_DMNAMEDPIPE: mode bit for named pipe (9P2000.u)
+ * @P9_DMSOCKET: mode bit for socket (9P2000.u)
+ * @P9_DMSETUID: mode bit for setuid (9P2000.u)
+ * @P9_DMSETGID: mode bit for setgid (9P2000.u)
+ * @P9_DMSETVTX: mode bit for sticky bit (9P2000.u)
+ *
+ * 9P permissions differ slightly from Posix standard modes.
+ *
+ * See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
+ */
+enum p9_perm_t {
+	P9_DMDIR = 0x80000000,
+	P9_DMAPPEND = 0x40000000,
+	P9_DMEXCL = 0x20000000,
+	P9_DMMOUNT = 0x10000000,
+	P9_DMAUTH = 0x08000000,
+	P9_DMTMP = 0x04000000,
+/* 9P2000.u extensions */
+	P9_DMSYMLINK = 0x02000000,
+	P9_DMLINK = 0x01000000,
+	P9_DMDEVICE = 0x00800000,
+	P9_DMNAMEDPIPE = 0x00200000,
+	P9_DMSOCKET = 0x00100000,
+	P9_DMSETUID = 0x00080000,
+	P9_DMSETGID = 0x00040000,
+	P9_DMSETVTX = 0x00010000,
+};
+
+/* 9p2000.L open flags */
+#define P9_DOTL_RDONLY        00000000
+#define P9_DOTL_WRONLY        00000001
+#define P9_DOTL_RDWR          00000002
+#define P9_DOTL_NOACCESS      00000003
+#define P9_DOTL_CREATE        00000100
+#define P9_DOTL_EXCL          00000200
+#define P9_DOTL_NOCTTY        00000400
+#define P9_DOTL_TRUNC         00001000
+#define P9_DOTL_APPEND        00002000
+#define P9_DOTL_NONBLOCK      00004000
+#define P9_DOTL_DSYNC         00010000
+#define P9_DOTL_FASYNC        00020000
+#define P9_DOTL_DIRECT        00040000
+#define P9_DOTL_LARGEFILE     00100000
+#define P9_DOTL_DIRECTORY     00200000
+#define P9_DOTL_NOFOLLOW      00400000
+#define P9_DOTL_NOATIME       01000000
+#define P9_DOTL_CLOEXEC       02000000
+#define P9_DOTL_SYNC          04000000
+
+/* 9p2000.L at flags */
+#define P9_DOTL_AT_REMOVEDIR		0x200
+
+/* 9p2000.L lock type */
+#define P9_LOCK_TYPE_RDLCK 0
+#define P9_LOCK_TYPE_WRLCK 1
+#define P9_LOCK_TYPE_UNLCK 2
+
+/**
+ * enum p9_qid_t - QID types
+ * @P9_QTDIR: directory
+ * @P9_QTAPPEND: append-only
+ * @P9_QTEXCL: excluse use (only one open handle allowed)
+ * @P9_QTMOUNT: mount points
+ * @P9_QTAUTH: authentication file
+ * @P9_QTTMP: non-backed-up files
+ * @P9_QTSYMLINK: symbolic links (9P2000.u)
+ * @P9_QTLINK: hard-link (9P2000.u)
+ * @P9_QTFILE: normal files
+ *
+ * QID types are a subset of permissions - they are primarily
+ * used to differentiate semantics for a file system entity via
+ * a jump-table.  Their value is also the most significant 16 bits
+ * of the permission_t
+ *
+ * See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
+ */
+enum p9_qid_t {
+	P9_QTDIR = 0x80,
+	P9_QTAPPEND = 0x40,
+	P9_QTEXCL = 0x20,
+	P9_QTMOUNT = 0x10,
+	P9_QTAUTH = 0x08,
+	P9_QTTMP = 0x04,
+	P9_QTSYMLINK = 0x02,
+	P9_QTLINK = 0x01,
+	P9_QTFILE = 0x00,
+};
+
+/* 9P Magic Numbers */
+#define P9_NOTAG	((u16)(~0))
+#define P9_NOFID	((u32)(~0))
+#define P9_MAXWELEM	16
+
+/* Minimal header size: size[4] type[1] tag[2] */
+#define P9_HDRSZ	7
+
+/* ample room for Twrite/Rread header */
+#define P9_IOHDRSZ	24
+
+/* Room for readdir header */
+#define P9_READDIRHDRSZ	24
+
+/* size of header for zero copy read/write */
+#define P9_ZC_HDR_SZ 4096
+
+/* maximum length of an error string */
+#define P9_ERRMAX 128
+
+/**
+ * struct p9_qid - file system entity information
+ * @type: 8-bit type &p9_qid_t
+ * @version: 16-bit monotonically incrementing version number
+ * @path: 64-bit per-server-unique ID for a file system element
+ *
+ * qids are identifiers used by 9P servers to track file system
+ * entities.  The type is used to differentiate semantics for operations
+ * on the entity (ie. read means something different on a directory than
+ * on a file).  The path provides a server unique index for an entity
+ * (roughly analogous to an inode number), while the version is updated
+ * every time a file is modified and can be used to maintain cache
+ * coherency between clients and serves.
+ * Servers will often differentiate purely synthetic entities by setting
+ * their version to 0, signaling that they should never be cached and
+ * should be accessed synchronously.
+ *
+ * See Also://plan9.bell-labs.com/magic/man2html/2/stat
+ */
+
+struct p9_qid {
+	u8 type;
+	u32 version;
+	u64 path;
+};
+
+/**
+ * struct p9_wstat - file system metadata information
+ * @size: length prefix for this stat structure instance
+ * @type: the type of the server (equivalent to a major number)
+ * @dev: the sub-type of the server (equivalent to a minor number)
+ * @qid: unique id from the server of type &p9_qid
+ * @mode: Plan 9 format permissions of type &p9_perm_t
+ * @atime: Last access/read time
+ * @mtime: Last modify/write time
+ * @length: file length
+ * @name: last element of path (aka filename)
+ * @uid: owner name
+ * @gid: group owner
+ * @muid: last modifier
+ * @extension: area used to encode extended UNIX support
+ * @n_uid: numeric user id of owner (part of 9p2000.u extension)
+ * @n_gid: numeric group id (part of 9p2000.u extension)
+ * @n_muid: numeric user id of laster modifier (part of 9p2000.u extension)
+ *
+ * See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
+ */
+
+struct p9_wstat {
+	u16 size;
+	u16 type;
+	u32 dev;
+	struct p9_qid qid;
+	u32 mode;
+	u32 atime;
+	u32 mtime;
+	u64 length;
+	const char *name;
+	const char *uid;
+	const char *gid;
+	const char *muid;
+	char *extension;	/* 9p2000.u extensions */
+	kuid_t n_uid;		/* 9p2000.u extensions */
+	kgid_t n_gid;		/* 9p2000.u extensions */
+	kuid_t n_muid;		/* 9p2000.u extensions */
+};
+
+struct p9_stat_dotl {
+	u64 st_result_mask;
+	struct p9_qid qid;
+	u32 st_mode;
+	kuid_t st_uid;
+	kgid_t st_gid;
+	u64 st_nlink;
+	u64 st_rdev;
+	u64 st_size;
+	u64 st_blksize;
+	u64 st_blocks;
+	u64 st_atime_sec;
+	u64 st_atime_nsec;
+	u64 st_mtime_sec;
+	u64 st_mtime_nsec;
+	u64 st_ctime_sec;
+	u64 st_ctime_nsec;
+	u64 st_btime_sec;
+	u64 st_btime_nsec;
+	u64 st_gen;
+	u64 st_data_version;
+};
+
+#define P9_STATS_MODE		0x00000001ULL
+#define P9_STATS_NLINK		0x00000002ULL
+#define P9_STATS_UID		0x00000004ULL
+#define P9_STATS_GID		0x00000008ULL
+#define P9_STATS_RDEV		0x00000010ULL
+#define P9_STATS_ATIME		0x00000020ULL
+#define P9_STATS_MTIME		0x00000040ULL
+#define P9_STATS_CTIME		0x00000080ULL
+#define P9_STATS_INO		0x00000100ULL
+#define P9_STATS_SIZE		0x00000200ULL
+#define P9_STATS_BLOCKS		0x00000400ULL
+
+#define P9_STATS_BTIME		0x00000800ULL
+#define P9_STATS_GEN		0x00001000ULL
+#define P9_STATS_DATA_VERSION	0x00002000ULL
+
+#define P9_STATS_BASIC		0x000007ffULL /* Mask for fields up to BLOCKS */
+#define P9_STATS_ALL		0x00003fffULL /* Mask for All fields above */
+
+/**
+ * struct p9_iattr_dotl - P9 inode attribute for setattr
+ * @valid: bitfield specifying which fields are valid
+ *         same as in struct iattr
+ * @mode: File permission bits
+ * @uid: user id of owner
+ * @gid: group id
+ * @size: File size
+ * @atime_sec: Last access time, seconds
+ * @atime_nsec: Last access time, nanoseconds
+ * @mtime_sec: Last modification time, seconds
+ * @mtime_nsec: Last modification time, nanoseconds
+ */
+
+struct p9_iattr_dotl {
+	u32 valid;
+	u32 mode;
+	kuid_t uid;
+	kgid_t gid;
+	u64 size;
+	u64 atime_sec;
+	u64 atime_nsec;
+	u64 mtime_sec;
+	u64 mtime_nsec;
+};
+
+#define P9_LOCK_SUCCESS 0
+#define P9_LOCK_BLOCKED 1
+#define P9_LOCK_ERROR 2
+#define P9_LOCK_GRACE 3
+
+#define P9_LOCK_FLAGS_BLOCK 1
+#define P9_LOCK_FLAGS_RECLAIM 2
+
+/* struct p9_flock: POSIX lock structure
+ * @type - type of lock
+ * @flags - lock flags
+ * @start - starting offset of the lock
+ * @length - number of bytes
+ * @proc_id - process id which wants to take lock
+ * @client_id - client id
+ */
+
+struct p9_flock {
+	u8 type;
+	u32 flags;
+	u64 start;
+	u64 length;
+	u32 proc_id;
+	char *client_id;
+};
+
+/* struct p9_getlock: getlock structure
+ * @type - type of lock
+ * @start - starting offset of the lock
+ * @length - number of bytes
+ * @proc_id - process id which wants to take lock
+ * @client_id - client id
+ */
+
+struct p9_getlock {
+	u8 type;
+	u64 start;
+	u64 length;
+	u32 proc_id;
+	char *client_id;
+};
+
+struct p9_rstatfs {
+	u32 type;
+	u32 bsize;
+	u64 blocks;
+	u64 bfree;
+	u64 bavail;
+	u64 files;
+	u64 ffree;
+	u64 fsid;
+	u32 namelen;
+};
+
+/**
+ * struct p9_fcall - primary packet structure
+ * @size: prefixed length of the structure
+ * @id: protocol operating identifier of type &p9_msg_t
+ * @tag: transaction id of the request
+ * @offset: used by marshalling routines to track current position in buffer
+ * @capacity: used by marshalling routines to track total malloc'd capacity
+ * @sdata: payload
+ *
+ * &p9_fcall represents the structure for all 9P RPC
+ * transactions.  Requests are packaged into fcalls, and reponses
+ * must be extracted from them.
+ *
+ * See Also: http://plan9.bell-labs.com/magic/man2html/2/fcall
+ */
+
+struct p9_fcall {
+	u32 size;
+	u8 id;
+	u16 tag;
+
+	size_t offset;
+	size_t capacity;
+
+	struct kmem_cache *cache;
+	u8 *sdata;
+};
+
+int p9_errstr2errno(char *errstr, int len);
+
+int p9_error_init(void);
+#endif /* NET_9P_H */
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 */
diff --git a/include/net/9p/transport.h b/include/net/9p/transport.h
new file mode 100644
index 000000000..766ec07c9
--- /dev/null
+++ b/include/net/9p/transport.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Transport Definition
+ *
+ *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ */
+
+#ifndef NET_9P_TRANSPORT_H
+#define NET_9P_TRANSPORT_H
+
+#include <linux/module.h>
+
+#define P9_DEF_MIN_RESVPORT	(665U)
+#define P9_DEF_MAX_RESVPORT	(1023U)
+
+/**
+ * struct p9_trans_module - transport module interface
+ * @list: used to maintain a list of currently available transports
+ * @name: the human-readable name of the transport
+ * @maxsize: transport provided maximum packet size
+ * @pooled_rbuffers: currently only set for RDMA transport which pulls the
+ *                   response buffers from a shared pool, and accordingly
+ *                   we're less flexible when choosing the response message
+ *                   size in this case
+ * @def: set if this transport should be considered the default
+ * @create: member function to create a new connection on this transport
+ * @close: member function to discard a connection on this transport
+ * @request: member function to issue a request to the transport
+ * @cancel: member function to cancel a request (if it hasn't been sent)
+ * @cancelled: member function to notify that a cancelled request will not
+ *             receive a reply
+ *
+ * This is the basic API for a transport module which is registered by the
+ * transport module with the 9P core network module and used by the client
+ * to instantiate a new connection on a transport.
+ *
+ * The transport module list is protected by v9fs_trans_lock.
+ */
+
+struct p9_trans_module {
+	struct list_head list;
+	char *name;		/* name of transport */
+	int maxsize;		/* max message size of transport */
+	bool pooled_rbuffers;
+	int def;		/* this transport should be default */
+	struct module *owner;
+	int (*create)(struct p9_client *client,
+		      const char *devname, char *args);
+	void (*close)(struct p9_client *client);
+	int (*request)(struct p9_client *client, struct p9_req_t *req);
+	int (*cancel)(struct p9_client *client, struct p9_req_t *req);
+	int (*cancelled)(struct p9_client *client, struct p9_req_t *req);
+	int (*zc_request)(struct p9_client *client, struct p9_req_t *req,
+			  struct iov_iter *uidata, struct iov_iter *uodata,
+			  int inlen, int outlen, int in_hdr_len);
+	int (*show_options)(struct seq_file *m, struct p9_client *client);
+};
+
+void v9fs_register_trans(struct p9_trans_module *m);
+void v9fs_unregister_trans(struct p9_trans_module *m);
+struct p9_trans_module *v9fs_get_trans_by_name(const char *s);
+struct p9_trans_module *v9fs_get_default_trans(void);
+void v9fs_put_trans(struct p9_trans_module *m);
+
+#define MODULE_ALIAS_9P(transport) \
+	MODULE_ALIAS("9p-" transport)
+
+#endif /* NET_9P_TRANSPORT_H */