LXR linux/fs/9p/v9fs.h

   1/*
   2 * V9FS definitions.
   3 *
   4 *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
   5 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   6 *
   7 *  This program is free software; you can redistribute it and/or modify
   8 *  it under the terms of the GNU General Public License version 2
   9 *  as published by the Free Software Foundation.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *  GNU General Public License for more details.
  15 *
  16 *  You should have received a copy of the GNU General Public License
  17 *  along with this program; if not, write to:
  18 *  Free Software Foundation
  19 *  51 Franklin Street, Fifth Floor
  20 *  Boston, MA  02111-1301  USA
  21 *
  22 */
  23
  24/**
  25 * enum p9_session_flags - option flags for each 9P session
  26 * @V9FS_EXTENDED: whether or not to use 9P2000.u extensions
  27 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
  28 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
  29 * @V9FS_ACCESS_ANY: use a single attach for all users
  30 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
  31 *
  32 * Session flags reflect options selected by users at mount time
  33 */
  34enum p9_session_flags {
  35        V9FS_EXTENDED           = 0x01,
  36        V9FS_ACCESS_SINGLE      = 0x02,
  37        V9FS_ACCESS_USER        = 0x04,
  38        V9FS_ACCESS_ANY         = 0x06,
  39        V9FS_ACCESS_MASK        = 0x06,
  40};
  41
  42/* possible values of ->cache */
  43/**
  44 * enum p9_cache_modes - user specified cache preferences
  45 * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
  46 * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
  47 *
  48 * eventually support loose, tight, time, session, default always none
  49 */
  50
  51enum p9_cache_modes {
  52        CACHE_NONE,
  53        CACHE_LOOSE,
  54        CACHE_FSCACHE,
  55};
  56
  57/**
  58 * struct v9fs_session_info - per-instance session information
  59 * @flags: session options of type &p9_session_flags
  60 * @nodev: set to 1 to disable device mapping
  61 * @debug: debug level
  62 * @afid: authentication handle
  63 * @cache: cache mode of type &p9_cache_modes
  64 * @cachetag: the tag of the cache associated with this session
  65 * @fscache: session cookie associated with FS-Cache
  66 * @options: copy of options string given by user
  67 * @uname: string user name to mount hierarchy as
  68 * @aname: mount specifier for remote hierarchy
  69 * @maxdata: maximum data to be sent/recvd per protocol message
  70 * @dfltuid: default numeric userid to mount hierarchy as
  71 * @dfltgid: default numeric groupid to mount hierarchy as
  72 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
  73 * @clnt: reference to 9P network client instantiated for this session
  74 * @slist: reference to list of registered 9p sessions
  75 *
  76 * This structure holds state for each session instance established during
  77 * a sys_mount() .
  78 *
  79 * Bugs: there seems to be a lot of state which could be condensed and/or
  80 * removed.
  81 */
  82
  83struct v9fs_session_info {
  84        /* options */
  85        unsigned char flags;
  86        unsigned char nodev;
  87        unsigned short debug;
  88        unsigned int afid;
  89        unsigned int cache;
  90#ifdef CONFIG_9P_FSCACHE
  91        char *cachetag;
  92        struct fscache_cookie *fscache;
  93#endif
  94
  95        char *uname;            /* user name to mount as */
  96        char *aname;            /* name of remote hierarchy being mounted */
  97        unsigned int maxdata;   /* max data for client interface */
  98        unsigned int dfltuid;   /* default uid/muid for legacy support */
  99        unsigned int dfltgid;   /* default gid for legacy support */
 100        u32 uid;                /* if ACCESS_SINGLE, the uid that has access */
 101        struct p9_client *clnt; /* 9p client */
 102        struct list_head slist; /* list of sessions registered with v9fs */
 103};
 104
 105struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
 106                                                                        char *);
 107void v9fs_session_close(struct v9fs_session_info *v9ses);
 108void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 109
 110#define V9FS_MAGIC 0x01021997
 111
 112/* other default globals */
 113#define V9FS_PORT       564
 114#define V9FS_DEFUSER    "nobody"
 115#define V9FS_DEFANAME   ""
 116#define V9FS_DEFUID     (-2)
 117#define V9FS_DEFGID     (-2)
 118
 119static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 120{
 121        return (inode->i_sb->s_fs_info);
 122}
 123
 124static inline int v9fs_extended(struct v9fs_session_info *v9ses)
 125{
 126        return v9ses->flags & V9FS_EXTENDED;
 127}
 128