LXR linux/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
  33enum 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};
  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
  51enum p9_cache_modes {
  52        CACHE_NONE,
  53        CACHE_MMAP,
  54        CACHE_LOOSE,
  55        CACHE_FSCACHE,
  56        nr__p9_cache_modes
  57};
  58
  59/**
  60 * struct v9fs_session_info - per-instance session information
  61 * @flags: session options of type &p9_session_flags
  62 * @nodev: set to 1 to disable device mapping
  63 * @debug: debug level
  64 * @afid: authentication handle
  65 * @cache: cache mode of type &p9_cache_modes
  66 * @cachetag: the tag of the cache associated with this session
  67 * @fscache: session cookie associated with FS-Cache
  68 * @uname: string user name to mount hierarchy as
  69 * @aname: mount specifier for remote hierarchy
  70 * @maxdata: maximum data to be sent/recvd per protocol message
  71 * @dfltuid: default numeric userid to mount hierarchy as
  72 * @dfltgid: default numeric groupid to mount hierarchy as
  73 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
  74 * @clnt: reference to 9P network client instantiated for this session
  75 * @slist: reference to list of registered 9p sessions
  76 *
  77 * This structure holds state for each session instance established during
  78 * a sys_mount() .
  79 *
  80 * Bugs: there seems to be a lot of state which could be condensed and/or
  81 * removed.
  82 */
  83
  84struct v9fs_session_info {
  85        /* options */
  86        unsigned char flags;
  87        unsigned char nodev;
  88        unsigned short debug;
  89        unsigned int afid;
  90        unsigned int cache;
  91#ifdef CONFIG_9P_FSCACHE
  92        char *cachetag;
  93        struct fscache_volume *fscache;
  94#endif
  95
  96        char *uname;            /* user name to mount as */
  97        char *aname;            /* name of remote hierarchy being mounted */
  98        unsigned int maxdata;   /* max data for client interface */
  99        kuid_t dfltuid;         /* default uid/muid for legacy support */
 100        kgid_t dfltgid;         /* default gid for legacy support */
 101        kuid_t uid;             /* if ACCESS_SINGLE, the uid that has access */
 102        struct p9_client *clnt; /* 9p client */
 103        struct list_head slist; /* list of sessions registered with v9fs */
 104        struct rw_semaphore rename_sem;
 105        long session_lock_timeout; /* retry interval for blocking locks */
 106};
 107
 108/* cache_validity flags */
 109#define V9FS_INO_INVALID_ATTR 0x01
 110
 111struct v9fs_inode {
 112        struct {
 113                /* These must be contiguous */
 114                struct inode    vfs_inode;      /* the VFS's inode record */
 115                struct netfs_i_context netfs_ctx; /* Netfslib context */
 116        };
 117        struct p9_qid qid;
 118        unsigned int cache_validity;
 119        struct p9_fid *writeback_fid;
 120        struct mutex v_mutex;
 121};
 122
 123static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 124{
 125        return container_of(inode, struct v9fs_inode, vfs_inode);
 126}
 127
 128static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
 129{
 130#ifdef CONFIG_9P_FSCACHE
 131        return netfs_i_cookie(&v9inode->vfs_inode);
 132#else
 133        return NULL;
 134#endif
 135}
 136
 137static inline struct fscache_volume *v9fs_session_cache(struct v9fs_session_info *v9ses)
 138{
 139#ifdef CONFIG_9P_FSCACHE
 140        return v9ses->fscache;
 141#else
 142        return NULL;
 143#endif
 144}
 145
 146
 147extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
 148
 149struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 150                                 const char *dev_name, char *data);
 151extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 152extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 153extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 154extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 155                                      unsigned int flags);
 156extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 157extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
 158extern int v9fs_vfs_rename(struct user_namespace *mnt_userns,
 159                           struct inode *old_dir, struct dentry *old_dentry,
 160                           struct inode *new_dir, struct dentry *new_dentry,
 161                           unsigned int flags);
 162extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
 163                                         struct p9_fid *fid,
 164                                         struct super_block *sb, int new);
 165extern const struct inode_operations v9fs_dir_inode_operations_dotl;
 166extern const struct inode_operations v9fs_file_inode_operations_dotl;
 167extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
 168extern const struct netfs_request_ops v9fs_req_ops;
 169extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 170                                              struct p9_fid *fid,
 171                                              struct super_block *sb, int new);
 172
 173/* other default globals */
 174#define V9FS_PORT       564
 175#define V9FS_DEFUSER    "nobody"
 176#define V9FS_DEFANAME   ""
 177#define V9FS_DEFUID     KUIDT_INIT(-2)
 178#define V9FS_DEFGID     KGIDT_INIT(-2)
 179
 180static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 181{
 182        return inode->i_sb->s_fs_info;
 183}
 184
 185static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
 186{
 187        return dentry->d_sb->s_fs_info;
 188}
 189
 190static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
 191{
 192        return v9ses->flags & V9FS_PROTO_2000U;
 193}
 194
 195static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
 196{
 197        return v9ses->flags & V9FS_PROTO_2000L;
 198}
 199
 200/**
 201 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
 202 * issuing a attribute request
 203 * @v9ses: session information
 204 * @fid: fid to issue attribute request for
 205 * @sb: superblock on which to create inode
 206 *
 207 */
 208static inline struct inode *
 209v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 210                        struct super_block *sb)
 211{
 212        if (v9fs_proto_dotl(v9ses))
 213                return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
 214        else
 215                return v9fs_inode_from_fid(v9ses, fid, sb, 0);
 216}
 217
 218/**
 219 * v9fs_get_new_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 */
 226static inline struct inode *
 227v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 228                            struct super_block *sb)
 229{
 230        if (v9fs_proto_dotl(v9ses))
 231                return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
 232        else
 233                return v9fs_inode_from_fid(v9ses, fid, sb, 1);
 234}
 235
 236#endif
 237