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#include <linux/fs_parser.h>
 14#include <net/9p/client.h>
 15#include <net/9p/transport.h>
 16
 17/**
 18 * enum p9_session_flags - option flags for each 9P session
 19 * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
 20 * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
 21 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
 22 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
 23 * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
 24 * @V9FS_ACCESS_ANY: use a single attach for all users
 25 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
 26 * @V9FS_POSIX_ACL: POSIX ACLs are enforced
 27 *
 28 * Session flags reflect options selected by users at mount time
 29 */
 30#define	V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
 31			 V9FS_ACCESS_USER |   \
 32			 V9FS_ACCESS_CLIENT)
 33#define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
 34#define V9FS_ACL_MASK V9FS_POSIX_ACL
 35
 36enum p9_session_flags {
 37	V9FS_PROTO_2000U    = 0x01,
 38	V9FS_PROTO_2000L    = 0x02,
 39	V9FS_ACCESS_SINGLE  = 0x04,
 40	V9FS_ACCESS_USER    = 0x08,
 41	V9FS_ACCESS_CLIENT  = 0x10,
 42	V9FS_POSIX_ACL      = 0x20,
 43	V9FS_NO_XATTR       = 0x40,
 44	V9FS_IGNORE_QV      = 0x80, /* ignore qid.version for cache hints */
 45	V9FS_DIRECT_IO      = 0x100,
 46	V9FS_SYNC           = 0x200
 47};
 48
 49/**
 50 * enum p9_cache_shortcuts - human readable cache preferences
 51 * @CACHE_SC_NONE: disable all caches
 52 * @CACHE_SC_READAHEAD: only provide caching for readahead
 53 * @CACHE_SC_MMAP: provide caching to enable mmap
 54 * @CACHE_SC_LOOSE: non-coherent caching for files and meta data
 55 * @CACHE_SC_FSCACHE: persistent non-coherent caching for files and meta-data
 56 *
 57 */
 58
 59enum p9_cache_shortcuts {
 60	CACHE_SC_NONE       = 0b00000000,
 61	CACHE_SC_READAHEAD  = 0b00000001,
 62	CACHE_SC_MMAP       = 0b00000101,
 63	CACHE_SC_LOOSE      = 0b00001111,
 64	CACHE_SC_FSCACHE    = 0b10001111,
 65};
 66
 67/**
 68 * enum p9_cache_bits - possible values of ->cache
 69 * @CACHE_NONE: caches disabled
 70 * @CACHE_FILE: file caching (open to close)
 71 * @CACHE_META: meta-data and directory caching
 72 * @CACHE_WRITEBACK: write-back caching for files
 73 * @CACHE_LOOSE: don't check cache consistency
 74 * @CACHE_FSCACHE: local persistent caches
 75 *
 76 */
 77
 78enum p9_cache_bits {
 79	CACHE_NONE          = 0b00000000,
 80	CACHE_FILE          = 0b00000001,
 81	CACHE_META          = 0b00000010,
 82	CACHE_WRITEBACK     = 0b00000100,
 83	CACHE_LOOSE         = 0b00001000,
 84	CACHE_FSCACHE       = 0b10000000,
 85};
 86
 87/**
 88 * struct v9fs_session_info - per-instance session information
 89 * @flags: session options of type &p9_session_flags
 90 * @nodev: set to 1 to disable device mapping
 91 * @debug: debug level
 92 * @afid: authentication handle
 93 * @cache: cache mode of type &p9_cache_bits
 94 * @cachetag: the tag of the cache associated with this session
 95 * @fscache: session cookie associated with FS-Cache
 96 * @uname: string user name to mount hierarchy as
 97 * @aname: mount specifier for remote hierarchy
 98 * @maxdata: maximum data to be sent/recvd per protocol message
 99 * @dfltuid: default numeric userid to mount hierarchy as
100 * @dfltgid: default numeric groupid to mount hierarchy as
101 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
102 * @clnt: reference to 9P network client instantiated for this session
103 * @slist: reference to list of registered 9p sessions
104 *
105 * This structure holds state for each session instance established during
106 * a sys_mount() .
107 *
108 * Bugs: there seems to be a lot of state which could be condensed and/or
109 * removed.
110 */
111
112struct v9fs_session_info {
113	/* options */
114	unsigned int flags;
115	unsigned char nodev;
116	unsigned short debug;
117	unsigned int afid;
118	unsigned int cache;
119#ifdef CONFIG_9P_FSCACHE
120	char *cachetag;
121	struct fscache_volume *fscache;
122#endif
123
124	char *uname;		/* user name to mount as */
125	char *aname;		/* name of remote hierarchy being mounted */
126	unsigned int maxdata;	/* max data for client interface */
127	kuid_t dfltuid;		/* default uid/muid for legacy support */
128	kgid_t dfltgid;		/* default gid for legacy support */
129	kuid_t uid;		/* if ACCESS_SINGLE, the uid that has access */
130	struct p9_client *clnt;	/* 9p client */
131	struct list_head slist; /* list of sessions registered with v9fs */
132	struct rw_semaphore rename_sem;
133	long session_lock_timeout; /* retry interval for blocking locks */
134};
135
136/* cache_validity flags */
137#define V9FS_INO_INVALID_ATTR 0x01
138
139struct v9fs_inode {
140	struct netfs_inode netfs; /* Netfslib context and vfs inode */
141	struct p9_qid qid;
142	unsigned int cache_validity;
143	struct mutex v_mutex;
144};
145
146static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
147{
148	return container_of(inode, struct v9fs_inode, netfs.inode);
149}
150
151static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
152{
153#ifdef CONFIG_9P_FSCACHE
154	return netfs_i_cookie(&v9inode->netfs);
155#else
156	return NULL;
157#endif
158}
159
160static inline struct fscache_volume *v9fs_session_cache(struct v9fs_session_info *v9ses)
161{
162#ifdef CONFIG_9P_FSCACHE
163	return v9ses->fscache;
164#else
165	return NULL;
166#endif
167}
168
169extern const struct fs_parameter_spec v9fs_param_spec[];
170
171extern int v9fs_parse_param(struct fs_context *fc, struct fs_parameter *param);
172extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
173
174struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
175				 struct fs_context *fc);
176extern void v9fs_session_close(struct v9fs_session_info *v9ses);
177extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
178extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
179extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
180				      unsigned int flags);
181extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
182extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
183extern int v9fs_vfs_rename(struct mnt_idmap *idmap,
184			   struct inode *old_dir, struct dentry *old_dentry,
185			   struct inode *new_dir, struct dentry *new_dentry,
186			   unsigned int flags);
187extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
188					 struct p9_fid *fid,
189					 struct super_block *sb, int new);
190extern const struct inode_operations v9fs_dir_inode_operations_dotl;
191extern const struct inode_operations v9fs_file_inode_operations_dotl;
192extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
193extern const struct netfs_request_ops v9fs_req_ops;
194extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
195					      struct p9_fid *fid,
196					      struct super_block *sb, int new);
197
198/* other default globals */
199#define V9FS_PORT	564
200#define V9FS_DEFUSER	"nobody"
201#define V9FS_DEFANAME	""
202#define V9FS_DEFUID	KUIDT_INIT(-2)
203#define V9FS_DEFGID	KGIDT_INIT(-2)
204
205static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
206{
207	return inode->i_sb->s_fs_info;
208}
209
210static inline struct v9fs_session_info *v9fs_dentry2v9ses(const struct dentry *dentry)
211{
212	return dentry->d_sb->s_fs_info;
213}
214
215static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
216{
217	return v9ses->flags & V9FS_PROTO_2000U;
218}
219
220static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
221{
222	return v9ses->flags & V9FS_PROTO_2000L;
223}
224
225/**
226 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
227 * issuing a attribute request
228 * @v9ses: session information
229 * @fid: fid to issue attribute request for
230 * @sb: superblock on which to create inode
231 *
232 */
233static inline struct inode *
234v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
235			struct super_block *sb)
236{
237	if (v9fs_proto_dotl(v9ses))
238		return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
239	else
240		return v9fs_inode_from_fid(v9ses, fid, sb, 0);
241}
242
243/**
244 * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
245 * issuing a attribute request
246 * @v9ses: session information
247 * @fid: fid to issue attribute request for
248 * @sb: superblock on which to create inode
249 *
250 */
251static inline struct inode *
252v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
253			    struct super_block *sb)
254{
255	if (v9fs_proto_dotl(v9ses))
256		return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
257	else
258		return v9fs_inode_from_fid(v9ses, fid, sb, 1);
259}
260
261#endif