fs/9p/v9fs.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * V9FS definitions.
   4  *
   5  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
   6  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   7  */
   8 #ifndef FS_9P_V9FS_H
   9 #define FS_9P_V9FS_H
  10
  11 #include <linux/backing-dev.h>
  12
  13 /**
  14  * enum p9_session_flags - option flags for each 9P session
  15  * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
  16  * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
  17  * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
  18  * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
  19  * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
  20  * @V9FS_ACCESS_ANY: use a single attach for all users
  21  * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
  22  * @V9FS_POSIX_ACL: POSIX ACLs are enforced
  23  *
  24  * Session flags reflect options selected by users at mount time
  25  */
  26 #define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
  27                          V9FS_ACCESS_USER |   \
  28                          V9FS_ACCESS_CLIENT)
  29 #define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
  30 #define V9FS_ACL_MASK V9FS_POSIX_ACL
  31
  32 enum p9_session_flags {
  33         V9FS_PROTO_2000U        = 0x01,
  34         V9FS_PROTO_2000L        = 0x02,
  35         V9FS_ACCESS_SINGLE      = 0x04,
  36         V9FS_ACCESS_USER        = 0x08,
  37         V9FS_ACCESS_CLIENT      = 0x10,
  38         V9FS_POSIX_ACL          = 0x20
  39 };
  40
  41 /* possible values of ->cache */
  42 /**
  43  * enum p9_cache_modes - user specified cache preferences
  44  * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
  45  * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
  46  *
  47  * eventually support loose, tight, time, session, default always none
  48  */
  49
  50 enum p9_cache_modes {
  51         CACHE_NONE,
  52         CACHE_MMAP,
  53         CACHE_LOOSE,
  54         CACHE_FSCACHE,
  55         nr__p9_cache_modes
  56 };
  57
  58 /**
  59  * struct v9fs_session_info - per-instance session information
  60  * @flags: session options of type &p9_session_flags
  61  * @nodev: set to 1 to disable device mapping
  62  * @debug: debug level
  63  * @afid: authentication handle
  64  * @cache: cache mode of type &p9_cache_modes
  65  * @cachetag: the tag of the cache associated with this session
  66  * @fscache: session cookie associated with FS-Cache
  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         kuid_t dfltuid;         /* default uid/muid for legacy support */
  99         kgid_t dfltgid;         /* default gid for legacy support */
 100         kuid_t 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         struct rw_semaphore rename_sem;
 104         long session_lock_timeout; /* retry interval for blocking locks */
 105 };
 106
 107 /* cache_validity flags */
 108 #define V9FS_INO_INVALID_ATTR 0x01
 109
 110 struct v9fs_inode {
 111 #ifdef CONFIG_9P_FSCACHE
 112         struct mutex fscache_lock;
 113         struct fscache_cookie *fscache;
 114 #endif
 115         struct p9_qid qid;
 116         unsigned int cache_validity;
 117         struct p9_fid *writeback_fid;
 118         struct mutex v_mutex;
 119         struct inode vfs_inode;
 120 };
 121
 122 static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 123 {
 124         return container_of(inode, struct v9fs_inode, vfs_inode);
 125 }
 126
 127 extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
 128
 129 struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
 130                                                                         char *);
 131 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 132 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 133 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 134 extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 135                         unsigned int flags);
 136 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 137 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
 138 extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 139                            struct inode *new_dir, struct dentry *new_dentry,
 140                            unsigned int flags);
 141 extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
 142                                          struct p9_fid *fid,
 143                                          struct super_block *sb, int new);
 144 extern const struct inode_operations v9fs_dir_inode_operations_dotl;
 145 extern const struct inode_operations v9fs_file_inode_operations_dotl;
 146 extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
 147 extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 148                                               struct p9_fid *fid,
 149                                               struct super_block *sb, int new);
 150
 151 /* other default globals */
 152 #define V9FS_PORT       564
 153 #define V9FS_DEFUSER    "nobody"
 154 #define V9FS_DEFANAME   ""
 155 #define V9FS_DEFUID     KUIDT_INIT(-2)
 156 #define V9FS_DEFGID     KGIDT_INIT(-2)
 157
 158 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 159 {
 160         return (inode->i_sb->s_fs_info);
 161 }
 162
 163 static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
 164 {
 165         return dentry->d_sb->s_fs_info;
 166 }
 167
 168 static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
 169 {
 170         return v9ses->flags & V9FS_PROTO_2000U;
 171 }
 172
 173 static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
 174 {
 175         return v9ses->flags & V9FS_PROTO_2000L;
 176 }
 177
 178 /**
 179  * v9fs_get_inode_from_fid - Helper routine to populate an inode by
 180  * issuing a attribute request
 181  * @v9ses: session information
 182  * @fid: fid to issue attribute request for
 183  * @sb: superblock on which to create inode
 184  *
 185  */
 186 static inline struct inode *
 187 v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 188                         struct super_block *sb)
 189 {
 190         if (v9fs_proto_dotl(v9ses))
 191                 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
 192         else
 193                 return v9fs_inode_from_fid(v9ses, fid, sb, 0);
 194 }
 195
 196 /**
 197  * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
 198  * issuing a attribute request
 199  * @v9ses: session information
 200  * @fid: fid to issue attribute request for
 201  * @sb: superblock on which to create inode
 202  *
 203  */
 204 static inline struct inode *
 205 v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 206                             struct super_block *sb)
 207 {
 208         if (v9fs_proto_dotl(v9ses))
 209                 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
 210         else
 211                 return v9fs_inode_from_fid(v9ses, fid, sb, 1);
 212 }
 213
 214 #endif