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 #include <linux/netfs.h>
  13
  14 /**
  15  * enum p9_session_flags - option flags for each 9P session
  16  * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
  17  * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
  18  * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
  19  * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
  20  * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
  21  * @V9FS_ACCESS_ANY: use a single attach for all users
  22  * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
  23  * @V9FS_POSIX_ACL: POSIX ACLs are enforced
  24  *
  25  * Session flags reflect options selected by users at mount time
  26  */
  27 #define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
  28                          V9FS_ACCESS_USER |   \
  29                          V9FS_ACCESS_CLIENT)
  30 #define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
  31 #define V9FS_ACL_MASK V9FS_POSIX_ACL
  32
  33 enum p9_session_flags {
  34         V9FS_PROTO_2000U    = 0x01,
  35         V9FS_PROTO_2000L    = 0x02,
  36         V9FS_ACCESS_SINGLE  = 0x04,
  37         V9FS_ACCESS_USER    = 0x08,
  38         V9FS_ACCESS_CLIENT  = 0x10,
  39         V9FS_POSIX_ACL      = 0x20,
  40         V9FS_NO_XATTR       = 0x40,
  41         V9FS_IGNORE_QV      = 0x80, /* ignore qid.version for cache hints */
  42         V9FS_DIRECT_IO      = 0x100,
  43         V9FS_SYNC           = 0x200
  44 };
  45
  46 /**
  47  * enum p9_cache_shortcuts - human readable cache preferences
  48  * @CACHE_SC_NONE: disable all caches
  49  * @CACHE_SC_READAHEAD: only provide caching for readahead
  50  * @CACHE_SC_MMAP: provide caching to enable mmap
  51  * @CACHE_SC_LOOSE: non-coherent caching for files and meta data
  52  * @CACHE_SC_FSCACHE: persistent non-coherent caching for files and meta-data
  53  *
  54  */
  55
  56 enum p9_cache_shortcuts {
  57         CACHE_SC_NONE       = 0b00000000,
  58         CACHE_SC_READAHEAD  = 0b00000001,
  59         CACHE_SC_MMAP       = 0b00000101,
  60         CACHE_SC_LOOSE      = 0b00001111,
  61         CACHE_SC_FSCACHE    = 0b10001111,
  62 };
  63
  64 /**
  65  * enum p9_cache_bits - possible values of ->cache
  66  * @CACHE_NONE: caches disabled
  67  * @CACHE_FILE: file caching (open to close)
  68  * @CACHE_META: meta-data and directory caching
  69  * @CACHE_WRITEBACK: write-back caching for files
  70  * @CACHE_LOOSE: don't check cache consistency
  71  * @CACHE_FSCACHE: local persistent caches
  72  *
  73  */
  74
  75 enum p9_cache_bits {
  76         CACHE_NONE          = 0b00000000,
  77         CACHE_FILE          = 0b00000001,
  78         CACHE_META          = 0b00000010,
  79         CACHE_WRITEBACK     = 0b00000100,
  80         CACHE_LOOSE         = 0b00001000,
  81         CACHE_FSCACHE       = 0b10000000,
  82 };
  83
  84 /**
  85  * struct v9fs_session_info - per-instance session information
  86  * @flags: session options of type &p9_session_flags
  87  * @nodev: set to 1 to disable device mapping
  88  * @debug: debug level
  89  * @afid: authentication handle
  90  * @cache: cache mode of type &p9_cache_bits
  91  * @cachetag: the tag of the cache associated with this session
  92  * @fscache: session cookie associated with FS-Cache
  93  * @uname: string user name to mount hierarchy as
  94  * @aname: mount specifier for remote hierarchy
  95  * @maxdata: maximum data to be sent/recvd per protocol message
  96  * @dfltuid: default numeric userid to mount hierarchy as
  97  * @dfltgid: default numeric groupid to mount hierarchy as
  98  * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
  99  * @clnt: reference to 9P network client instantiated for this session
 100  * @slist: reference to list of registered 9p sessions
 101  *
 102  * This structure holds state for each session instance established during
 103  * a sys_mount() .
 104  *
 105  * Bugs: there seems to be a lot of state which could be condensed and/or
 106  * removed.
 107  */
 108
 109 struct v9fs_session_info {
 110         /* options */
 111         unsigned int flags;
 112         unsigned char nodev;
 113         unsigned short debug;
 114         unsigned int afid;
 115         unsigned int cache;
 116 #ifdef CONFIG_9P_FSCACHE
 117         char *cachetag;
 118         struct fscache_volume *fscache;
 119 #endif
 120
 121         char *uname;            /* user name to mount as */
 122         char *aname;            /* name of remote hierarchy being mounted */
 123         unsigned int maxdata;   /* max data for client interface */
 124         kuid_t dfltuid;         /* default uid/muid for legacy support */
 125         kgid_t dfltgid;         /* default gid for legacy support */
 126         kuid_t uid;             /* if ACCESS_SINGLE, the uid that has access */
 127         struct p9_client *clnt; /* 9p client */
 128         struct list_head slist; /* list of sessions registered with v9fs */
 129         struct rw_semaphore rename_sem;
 130         long session_lock_timeout; /* retry interval for blocking locks */
 131 };
 132
 133 /* cache_validity flags */
 134 #define V9FS_INO_INVALID_ATTR 0x01
 135
 136 struct v9fs_inode {
 137         struct netfs_inode netfs; /* Netfslib context and vfs inode */
 138         struct p9_qid qid;
 139         unsigned int cache_validity;
 140         struct mutex v_mutex;
 141 };
 142
 143 static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 144 {
 145         return container_of(inode, struct v9fs_inode, netfs.inode);
 146 }
 147
 148 static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
 149 {
 150 #ifdef CONFIG_9P_FSCACHE
 151         return netfs_i_cookie(&v9inode->netfs);
 152 #else
 153         return NULL;
 154 #endif
 155 }
 156
 157 static inline struct fscache_volume *v9fs_session_cache(struct v9fs_session_info *v9ses)
 158 {
 159 #ifdef CONFIG_9P_FSCACHE
 160         return v9ses->fscache;
 161 #else
 162         return NULL;
 163 #endif
 164 }
 165
 166
 167 extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
 168
 169 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 170                                  const char *dev_name, char *data);
 171 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 172 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 173 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 174 extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 175                                       unsigned int flags);
 176 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 177 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
 178 extern int v9fs_vfs_rename(struct mnt_idmap *idmap,
 179                            struct inode *old_dir, struct dentry *old_dentry,
 180                            struct inode *new_dir, struct dentry *new_dentry,
 181                            unsigned int flags);
 182 extern struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid,
 183                                                 bool new);
 184 extern const struct inode_operations v9fs_dir_inode_operations_dotl;
 185 extern const struct inode_operations v9fs_file_inode_operations_dotl;
 186 extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
 187 extern const struct netfs_request_ops v9fs_req_ops;
 188 extern struct inode *v9fs_fid_iget_dotl(struct super_block *sb,
 189                                                 struct p9_fid *fid, bool new);
 190
 191 /* other default globals */
 192 #define V9FS_PORT       564
 193 #define V9FS_DEFUSER    "nobody"
 194 #define V9FS_DEFANAME   ""
 195 #define V9FS_DEFUID     KUIDT_INIT(-2)
 196 #define V9FS_DEFGID     KGIDT_INIT(-2)
 197
 198 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 199 {
 200         return inode->i_sb->s_fs_info;
 201 }
 202
 203 static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
 204 {
 205         return dentry->d_sb->s_fs_info;
 206 }
 207
 208 static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
 209 {
 210         return v9ses->flags & V9FS_PROTO_2000U;
 211 }
 212
 213 static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
 214 {
 215         return v9ses->flags & V9FS_PROTO_2000L;
 216 }
 217
 218 /**
 219  * v9fs_get_inode_from_fid - Helper routine to populate an inode by
 220  * issuing a attribute request
 221  * @v9ses: session information
 222  * @fid: fid to issue attribute request for
 223  * @sb: superblock on which to create inode
 224  *
 225  */
 226 static inline struct inode *
 227 v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 228                         struct super_block *sb, bool new)
 229 {
 230         if (v9fs_proto_dotl(v9ses))
 231                 return v9fs_fid_iget_dotl(sb, fid, new);
 232         else
 233                 return v9fs_fid_iget(sb, fid, new);
 234 }
 235
 236 #endif