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 #ifndef FS_9P_V9FS_H
  24 #define FS_9P_V9FS_H
  25
  26 #include <linux/backing-dev.h>
  27
  28 /**
  29  * enum p9_session_flags - option flags for each 9P session
  30  * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
  31  * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
  32  * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
  33  * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
  34  * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
  35  * @V9FS_ACCESS_ANY: use a single attach for all users
  36  * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
  37  * @V9FS_POSIX_ACL: POSIX ACLs are enforced
  38  *
  39  * Session flags reflect options selected by users at mount time
  40  */
  41 #define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
  42                          V9FS_ACCESS_USER |   \
  43                          V9FS_ACCESS_CLIENT)
  44 #define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
  45 #define V9FS_ACL_MASK V9FS_POSIX_ACL
  46
  47 enum p9_session_flags {
  48         V9FS_PROTO_2000U        = 0x01,
  49         V9FS_PROTO_2000L        = 0x02,
  50         V9FS_ACCESS_SINGLE      = 0x04,
  51         V9FS_ACCESS_USER        = 0x08,
  52         V9FS_ACCESS_CLIENT      = 0x10,
  53         V9FS_POSIX_ACL          = 0x20
  54 };
  55
  56 /* possible values of ->cache */
  57 /**
  58  * enum p9_cache_modes - user specified cache preferences
  59  * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
  60  * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
  61  *
  62  * eventually support loose, tight, time, session, default always none
  63  */
  64
  65 enum p9_cache_modes {
  66         CACHE_NONE,
  67         CACHE_MMAP,
  68         CACHE_LOOSE,
  69         CACHE_FSCACHE,
  70 };
  71
  72 /**
  73  * struct v9fs_session_info - per-instance session information
  74  * @flags: session options of type &p9_session_flags
  75  * @nodev: set to 1 to disable device mapping
  76  * @debug: debug level
  77  * @afid: authentication handle
  78  * @cache: cache mode of type &p9_cache_modes
  79  * @cachetag: the tag of the cache associated with this session
  80  * @fscache: session cookie associated with FS-Cache
  81  * @uname: string user name to mount hierarchy as
  82  * @aname: mount specifier for remote hierarchy
  83  * @maxdata: maximum data to be sent/recvd per protocol message
  84  * @dfltuid: default numeric userid to mount hierarchy as
  85  * @dfltgid: default numeric groupid to mount hierarchy as
  86  * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
  87  * @clnt: reference to 9P network client instantiated for this session
  88  * @slist: reference to list of registered 9p sessions
  89  *
  90  * This structure holds state for each session instance established during
  91  * a sys_mount() .
  92  *
  93  * Bugs: there seems to be a lot of state which could be condensed and/or
  94  * removed.
  95  */
  96
  97 struct v9fs_session_info {
  98         /* options */
  99         unsigned char flags;
 100         unsigned char nodev;
 101         unsigned short debug;
 102         unsigned int afid;
 103         unsigned int cache;
 104 #ifdef CONFIG_9P_FSCACHE
 105         char *cachetag;
 106         struct fscache_cookie *fscache;
 107 #endif
 108
 109         char *uname;            /* user name to mount as */
 110         char *aname;            /* name of remote hierarchy being mounted */
 111         unsigned int maxdata;   /* max data for client interface */
 112         kuid_t dfltuid;         /* default uid/muid for legacy support */
 113         kgid_t dfltgid;         /* default gid for legacy support */
 114         kuid_t uid;             /* if ACCESS_SINGLE, the uid that has access */
 115         struct p9_client *clnt; /* 9p client */
 116         struct list_head slist; /* list of sessions registered with v9fs */
 117         struct backing_dev_info bdi;
 118         struct rw_semaphore rename_sem;
 119         long session_lock_timeout; /* retry interval for blocking locks */
 120 };
 121
 122 /* cache_validity flags */
 123 #define V9FS_INO_INVALID_ATTR 0x01
 124
 125 struct v9fs_inode {
 126 #ifdef CONFIG_9P_FSCACHE
 127         struct mutex fscache_lock;
 128         struct fscache_cookie *fscache;
 129 #endif
 130         struct p9_qid qid;
 131         unsigned int cache_validity;
 132         struct p9_fid *writeback_fid;
 133         struct mutex v_mutex;
 134         struct inode vfs_inode;
 135 };
 136
 137 static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 138 {
 139         return container_of(inode, struct v9fs_inode, vfs_inode);
 140 }
 141
 142 struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
 143                                                                         char *);
 144 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 145 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 146 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 147 extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 148                         unsigned int flags);
 149 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 150 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
 151 extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 152                         struct inode *new_dir, struct dentry *new_dentry);
 153 extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
 154                                          struct p9_fid *fid,
 155                                          struct super_block *sb, int new);
 156 extern const struct inode_operations v9fs_dir_inode_operations_dotl;
 157 extern const struct inode_operations v9fs_file_inode_operations_dotl;
 158 extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
 159 extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 160                                               struct p9_fid *fid,
 161                                               struct super_block *sb, int new);
 162
 163 /* other default globals */
 164 #define V9FS_PORT       564
 165 #define V9FS_DEFUSER    "nobody"
 166 #define V9FS_DEFANAME   ""
 167 #define V9FS_DEFUID     KUIDT_INIT(-2)
 168 #define V9FS_DEFGID     KGIDT_INIT(-2)
 169
 170 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 171 {
 172         return (inode->i_sb->s_fs_info);
 173 }
 174
 175 static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
 176 {
 177         return dentry->d_sb->s_fs_info;
 178 }
 179
 180 static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
 181 {
 182         return v9ses->flags & V9FS_PROTO_2000U;
 183 }
 184
 185 static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
 186 {
 187         return v9ses->flags & V9FS_PROTO_2000L;
 188 }
 189
 190 /**
 191  * v9fs_get_inode_from_fid - Helper routine to populate an inode by
 192  * issuing a attribute request
 193  * @v9ses: session information
 194  * @fid: fid to issue attribute request for
 195  * @sb: superblock on which to create inode
 196  *
 197  */
 198 static inline struct inode *
 199 v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 200                         struct super_block *sb)
 201 {
 202         if (v9fs_proto_dotl(v9ses))
 203                 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
 204         else
 205                 return v9fs_inode_from_fid(v9ses, fid, sb, 0);
 206 }
 207
 208 /**
 209  * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
 210  * issuing a attribute request
 211  * @v9ses: session information
 212  * @fid: fid to issue attribute request for
 213  * @sb: superblock on which to create inode
 214  *
 215  */
 216 static inline struct inode *
 217 v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 218                             struct super_block *sb)
 219 {
 220         if (v9fs_proto_dotl(v9ses))
 221                 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
 222         else
 223                 return v9fs_inode_from_fid(v9ses, fid, sb, 1);
 224 }
 225
 226 #endif