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 #include <linux/backing-dev.h>
  24
  25 /**
  26  * enum p9_session_flags - option flags for each 9P session
  27  * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
  28  * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
  29  * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
  30  * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
  31  * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
  32  * @V9FS_ACCESS_ANY: use a single attach for all users
  33  * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
  34  * @V9FS_POSIX_ACL: POSIX ACLs are enforced
  35  *
  36  * Session flags reflect options selected by users at mount time
  37  */
  38 #define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
  39                          V9FS_ACCESS_USER |   \
  40                          V9FS_ACCESS_CLIENT)
  41 #define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
  42 #define V9FS_ACL_MASK V9FS_POSIX_ACL
  43
  44 enum p9_session_flags {
  45         V9FS_PROTO_2000U        = 0x01,
  46         V9FS_PROTO_2000L        = 0x02,
  47         V9FS_ACCESS_SINGLE      = 0x04,
  48         V9FS_ACCESS_USER        = 0x08,
  49         V9FS_ACCESS_CLIENT      = 0x10,
  50         V9FS_POSIX_ACL          = 0x20
  51 };
  52
  53 /* possible values of ->cache */
  54 /**
  55  * enum p9_cache_modes - user specified cache preferences
  56  * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
  57  * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
  58  *
  59  * eventually support loose, tight, time, session, default always none
  60  */
  61
  62 enum p9_cache_modes {
  63         CACHE_NONE,
  64         CACHE_LOOSE,
  65         CACHE_FSCACHE,
  66 };
  67
  68 /**
  69  * struct v9fs_session_info - per-instance session information
  70  * @flags: session options of type &p9_session_flags
  71  * @nodev: set to 1 to disable device mapping
  72  * @debug: debug level
  73  * @afid: authentication handle
  74  * @cache: cache mode of type &p9_cache_modes
  75  * @cachetag: the tag of the cache associated with this session
  76  * @fscache: session cookie associated with FS-Cache
  77  * @options: copy of options string given by user
  78  * @uname: string user name to mount hierarchy as
  79  * @aname: mount specifier for remote hierarchy
  80  * @maxdata: maximum data to be sent/recvd per protocol message
  81  * @dfltuid: default numeric userid to mount hierarchy as
  82  * @dfltgid: default numeric groupid to mount hierarchy as
  83  * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
  84  * @clnt: reference to 9P network client instantiated for this session
  85  * @slist: reference to list of registered 9p sessions
  86  *
  87  * This structure holds state for each session instance established during
  88  * a sys_mount() .
  89  *
  90  * Bugs: there seems to be a lot of state which could be condensed and/or
  91  * removed.
  92  */
  93
  94 struct v9fs_session_info {
  95         /* options */
  96         unsigned char flags;
  97         unsigned char nodev;
  98         unsigned short debug;
  99         unsigned int afid;
 100         unsigned int cache;
 101 #ifdef CONFIG_9P_FSCACHE
 102         char *cachetag;
 103         struct fscache_cookie *fscache;
 104 #endif
 105
 106         char *uname;            /* user name to mount as */
 107         char *aname;            /* name of remote hierarchy being mounted */
 108         unsigned int maxdata;   /* max data for client interface */
 109         unsigned int dfltuid;   /* default uid/muid for legacy support */
 110         unsigned int dfltgid;   /* default gid for legacy support */
 111         u32 uid;                /* if ACCESS_SINGLE, the uid that has access */
 112         struct p9_client *clnt; /* 9p client */
 113         struct list_head slist; /* list of sessions registered with v9fs */
 114         struct backing_dev_info bdi;
 115         struct rw_semaphore rename_sem;
 116         struct p9_fid *root_fid; /* Used for file system sync */
 117 };
 118
 119 /* cache_validity flags */
 120 #define V9FS_INO_INVALID_ATTR 0x01
 121
 122 struct v9fs_inode {
 123 #ifdef CONFIG_9P_FSCACHE
 124         spinlock_t fscache_lock;
 125         struct fscache_cookie *fscache;
 126         struct p9_qid *fscache_key;
 127 #endif
 128         unsigned int cache_validity;
 129         struct p9_fid *writeback_fid;
 130         struct inode vfs_inode;
 131 };
 132
 133 static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 134 {
 135         return container_of(inode, struct v9fs_inode, vfs_inode);
 136 }
 137
 138 struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
 139                                                                         char *);
 140 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 141 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 142 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 143 extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 144                         struct nameidata *nameidata);
 145 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 146 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
 147 extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 148                         struct inode *new_dir, struct dentry *new_dentry);
 149 extern void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd,
 150                         void *p);
 151 extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
 152                                          struct p9_fid *fid,
 153                                          struct super_block *sb);
 154 extern const struct inode_operations v9fs_dir_inode_operations_dotl;
 155 extern const struct inode_operations v9fs_file_inode_operations_dotl;
 156 extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
 157 extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 158                                               struct p9_fid *fid,
 159                                               struct super_block *sb);
 160
 161 /* other default globals */
 162 #define V9FS_PORT       564
 163 #define V9FS_DEFUSER    "nobody"
 164 #define V9FS_DEFANAME   ""
 165 #define V9FS_DEFUID     (-2)
 166 #define V9FS_DEFGID     (-2)
 167
 168 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 169 {
 170         return (inode->i_sb->s_fs_info);
 171 }
 172
 173 static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
 174 {
 175         return v9ses->flags & V9FS_PROTO_2000U;
 176 }
 177
 178 static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
 179 {
 180         return v9ses->flags & V9FS_PROTO_2000L;
 181 }
 182
 183 /**
 184  * v9fs_get_inode_from_fid - Helper routine to populate an inode by
 185  * issuing a attribute request
 186  * @v9ses: session information
 187  * @fid: fid to issue attribute request for
 188  * @sb: superblock on which to create inode
 189  *
 190  */
 191 static inline struct inode *
 192 v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 193                         struct super_block *sb)
 194 {
 195         if (v9fs_proto_dotl(v9ses))
 196                 return v9fs_inode_from_fid_dotl(v9ses, fid, sb);
 197         else
 198                 return v9fs_inode_from_fid(v9ses, fid, sb);
 199 }