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
  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
  32enum 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
  50enum 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
  83struct 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
 110struct 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
 122static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 123{
 124        return container_of(inode, struct v9fs_inode, vfs_inode);
 125}
 126
 127extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
 128
 129struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
 130                                                                        char *);
 131extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 132extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 133extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 134extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 135                        unsigned int flags);
 136extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 137extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
 138extern int v9fs_vfs_rename(struct user_namespace *mnt_userns,
 139                           struct inode *old_dir, struct dentry *old_dentry,
 140                           struct inode *new_dir, struct dentry *new_dentry,
 141                           unsigned int flags);
 142extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
 143                                         struct p9_fid *fid,
 144                                         struct super_block *sb, int new);
 145extern const struct inode_operations v9fs_dir_inode_operations_dotl;
 146extern const struct inode_operations v9fs_file_inode_operations_dotl;
 147extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
 148extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 149                                              struct p9_fid *fid,
 150                                              struct super_block *sb, int new);
 151
 152/* other default globals */
 153#define V9FS_PORT       564
 154#define V9FS_DEFUSER    "nobody"
 155#define V9FS_DEFANAME   ""
 156#define V9FS_DEFUID     KUIDT_INIT(-2)
 157#define V9FS_DEFGID     KGIDT_INIT(-2)
 158
 159static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 160{
 161        return (inode->i_sb->s_fs_info);
 162}
 163
 164static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
 165{
 166        return dentry->d_sb->s_fs_info;
 167}
 168
 169static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
 170{
 171        return v9ses->flags & V9FS_PROTO_2000U;
 172}
 173
 174static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
 175{
 176        return v9ses->flags & V9FS_PROTO_2000L;
 177}
 178
 179/**
 180 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
 181 * issuing a attribute request
 182 * @v9ses: session information
 183 * @fid: fid to issue attribute request for
 184 * @sb: superblock on which to create inode
 185 *
 186 */
 187static inline struct inode *
 188v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 189                        struct super_block *sb)
 190{
 191        if (v9fs_proto_dotl(v9ses))
 192                return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
 193        else
 194                return v9fs_inode_from_fid(v9ses, fid, sb, 0);
 195}
 196
 197/**
 198 * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
 199 * issuing a attribute request
 200 * @v9ses: session information
 201 * @fid: fid to issue attribute request for
 202 * @sb: superblock on which to create inode
 203 *
 204 */
 205static inline struct inode *
 206v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 207                            struct super_block *sb)
 208{
 209        if (v9fs_proto_dotl(v9ses))
 210                return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
 211        else
 212                return v9fs_inode_from_fid(v9ses, fid, sb, 1);
 213}
 214
 215#endif
 216