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  */
  34 enum 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
  51 enum 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
  83 struct 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
 105 struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
 106                                                                         char *);
 107 void v9fs_session_close(struct v9fs_session_info *v9ses);
 108 void 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
 119 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 120 {
 121         return (inode->i_sb->s_fs_info);
 122 }
 123
 124 static inline int v9fs_extended(struct v9fs_session_info *v9ses)
 125 {
 126         return v9ses->flags & V9FS_EXTENDED;
 127 }