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9p: Documentation updates

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The kernel-doc comments of much of the 9p system have been in disarray since
reorganization.  This patch fixes those problems, adds additional documentation
and a template book which collects the 9p information.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This commit is contained in:
Eric Van Hensbergen
2008-03-05 07:08:09 -06:00
committed by Eric Van Hensbergen
parent b32a09db4f
commit ee443996a3
18 changed files with 852 additions and 122 deletions
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235
include/net/9p/9p.h
View File

@@ -29,14 +29,31 @@
#ifdef CONFIG_NET_9P_DEBUG
#define P9_DEBUG_ERROR (1<<0)
#define P9_DEBUG_9P (1<<2)
#define P9_DEBUG_VFS (1<<3)
#define P9_DEBUG_CONV (1<<4)
#define P9_DEBUG_MUX (1<<5)
#define P9_DEBUG_TRANS (1<<6)
#define P9_DEBUG_SLABS (1<<7)
#define P9_DEBUG_FCALL (1<<8)
/**
* 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
*
* 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),
};
extern unsigned int p9_debug_level;
@@ -62,9 +79,47 @@ do { \
format , __FUNCTION__, task_pid_nr(current), ## arg); \
} while (0)
/**
* enum p9_msg_t - 9P message types
* @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 transfered 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
*/
/* Message Types */
enum {
enum p9_msg_t {
P9_TVERSION = 100,
P9_RVERSION,
P9_TAUTH = 102,
@@ -95,30 +150,71 @@ enum {
P9_RWSTAT,
};
/* open modes */
enum {
/**
* 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_OEXCL = 0x04,
P9_OTRUNC = 0x10,
P9_OREXEC = 0x20,
P9_ORCLOSE = 0x40,
P9_OAPPEND = 0x80,
P9_OEXCL = 0x1000,
};
/* permissions */
enum {
/**
* enum p9_perm_t - 9P permissions
* @P9_DMDIR: mode bite 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 bite 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,
/* 9P2000.u extensions */
P9_DMDEVICE = 0x00800000,
P9_DMNAMEDPIPE = 0x00200000,
P9_DMSOCKET = 0x00100000,
@@ -127,8 +223,26 @@ enum {
P9_DMSETVTX = 0x00010000,
};
/* qid.types */
enum {
/**
* 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 signifigant 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,
@@ -140,6 +254,7 @@ enum {
P9_QTFILE = 0x00,
};
/* 9P Magic Numbers */
#define P9_NOTAG (u16)(~0)
#define P9_NOFID (u32)(~0)
#define P9_MAXWELEM 16
@@ -147,19 +262,69 @@ enum {
/* ample room for Twrite/Rread header */
#define P9_IOHDRSZ 24
/**
* struct p9_str - length prefixed string type
* @len: length of the string
* @str: the string
*
* The protocol uses length prefixed strings for all
* string data, so we replicate that for our internal
* string members.
*/
struct p9_str {
u16 len;
char *str;
};
/* qids are the unique ID for a file (like an inode */
/**
* 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;
};
/* Plan 9 file metadata (stat) structure */
/**
* struct p9_stat - file system metadata information
* @size: length prefix for this stat structure instance
* @type: the type of the server (equivilent to a major number)
* @dev: the sub-type of the server (equivilent 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) in type &p9_str
* @uid: owner name in type &p9_str
* @gid: group owner in type &p9_str
* @muid: last modifier in type &p9_str
* @extension: area used to encode extended UNIX support in type &p9_str
* @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_stat {
u16 size;
u16 type;
@@ -179,10 +344,14 @@ struct p9_stat {
u32 n_muid; /* 9p2000.u extensions */
};
/* file metadata (stat) structure used to create Twstat message
The is similar to p9_stat, but the strings don't point to
the same memory block and should be freed separately
*/
/*
* file metadata (stat) structure used to create Twstat message
* The is identical to &p9_stat, but the strings don't point to
* the same memory block and should be freed separately
*
* See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
*/
struct p9_wstat {
u16 size;
u16 type;
@@ -335,10 +504,20 @@ struct p9_twstat {
struct p9_rwstat {
};
/*
* fcall is the primary packet structure
*
*/
/**
* 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
* @sdata: payload
* @params: per-operation parameters
*
* &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;

35
include/net/9p/client.h
View File

@@ -26,6 +26,23 @@
#ifndef NET_9P_CLIENT_H
#define NET_9P_CLIENT_H
/**
* 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
*
* The client structure is used to keep track of various per-client
* state that has been instantiated.
*
* Bugs: duplicated data and potentially unnecessary elements.
*/
struct p9_client {
spinlock_t lock; /* protect client structure */
int msize;
@@ -38,6 +55,24 @@ struct p9_client {
struct list_head fidlist;
};
/**
* 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
* @rdir_pos: (unused?)
* @rdir_fcall: holds response of last directory read request
* @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;

43
include/net/9p/transport.h
View File

@@ -26,12 +26,40 @@
#ifndef NET_9P_TRANSPORT_H
#define NET_9P_TRANSPORT_H
/**
* 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,
};
/**
* struct p9_trans - per-transport state and API
* @status: transport &p9_trans_status
* @msize: negotiated maximum packet size (duplicate from client)
* @extended: negotiated protocol extensions (duplicate from client)
* @priv: transport private data
* @close: member function to disconnect and close the transport
* @rpc: member function to issue a request to the transport
*
* This is the basic API for a transport instance. It is used as
* a handle by the client to issue requests. This interface is currently
* in flux during reorganization.
*
* Bugs: there is lots of duplicated data here and its not clear that
* the member functions need to be per-instance versus per transport
* module.
*/
struct p9_trans {
enum p9_trans_status status;
int msize;
@@ -42,6 +70,21 @@ struct p9_trans {
struct p9_fcall **rc);
};
/**
* 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
* @def: set if this transport should be considered the default
* @create: member function to create a new connection on this transport
*
* 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.
*
* Bugs: the transport module list isn't protected.
*/
struct p9_trans_module {
struct list_head list;
char *name; /* name of transport */