korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-14 15:54:15 +08:00
Code Issues Packages Projects Releases Wiki Activity
1907e0fec1
linux/fs/9p/v9fs.h
Christian Brauner e18275ae55
fs: port ->rename() to pass mnt_idmap 
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:26 +01:00

233 lines
7.2 KiB
C
Raw Blame History

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* V9FS definitions.
*
* Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*/
#ifndef FS_9P_V9FS_H
#define FS_9P_V9FS_H
#include <linux/backing-dev.h>
#include <linux/netfs.h>
/**
* enum p9_session_flags - option flags for each 9P session
* @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
* @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
* @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
* @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
* @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
* @V9FS_ACCESS_ANY: use a single attach for all users
* @V9FS_ACCESS_MASK: bit mask of different ACCESS options
* @V9FS_POSIX_ACL: POSIX ACLs are enforced
*
* Session flags reflect options selected by users at mount time
*/
#define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
V9FS_ACCESS_USER | \
V9FS_ACCESS_CLIENT)
#define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
#define V9FS_ACL_MASK V9FS_POSIX_ACL
enum p9_session_flags {
V9FS_PROTO_2000U = 0x01,
V9FS_PROTO_2000L = 0x02,
V9FS_ACCESS_SINGLE = 0x04,
V9FS_ACCESS_USER = 0x08,
V9FS_ACCESS_CLIENT = 0x10,
V9FS_POSIX_ACL = 0x20
};
/* possible values of ->cache */
/**
* enum p9_cache_modes - user specified cache preferences
* @CACHE_NONE: do not cache data, dentries, or directory contents (default)
* @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
*
* eventually support loose, tight, time, session, default always none
*/
enum p9_cache_modes {
CACHE_NONE,
CACHE_MMAP,
CACHE_LOOSE,
CACHE_FSCACHE,
nr__p9_cache_modes
};
/**
* struct v9fs_session_info - per-instance session information
* @flags: session options of type &p9_session_flags
* @nodev: set to 1 to disable device mapping
* @debug: debug level
* @afid: authentication handle
* @cache: cache mode of type &p9_cache_modes
* @cachetag: the tag of the cache associated with this session
* @fscache: session cookie associated with FS-Cache
* @uname: string user name to mount hierarchy as
* @aname: mount specifier for remote hierarchy
* @maxdata: maximum data to be sent/recvd per protocol message
* @dfltuid: default numeric userid to mount hierarchy as
* @dfltgid: default numeric groupid to mount hierarchy as
* @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
* @clnt: reference to 9P network client instantiated for this session
* @slist: reference to list of registered 9p sessions
*
* This structure holds state for each session instance established during
* a sys_mount() .
*
* Bugs: there seems to be a lot of state which could be condensed and/or
* removed.
*/
struct v9fs_session_info {
/* options */
unsigned char flags;
unsigned char nodev;
unsigned short debug;
unsigned int afid;
unsigned int cache;
#ifdef CONFIG_9P_FSCACHE
char *cachetag;
struct fscache_volume *fscache;
#endif
char *uname; /* user name to mount as */
char *aname; /* name of remote hierarchy being mounted */
unsigned int maxdata; /* max data for client interface */
kuid_t dfltuid; /* default uid/muid for legacy support */
kgid_t dfltgid; /* default gid for legacy support */
kuid_t uid; /* if ACCESS_SINGLE, the uid that has access */
struct p9_client *clnt; /* 9p client */
struct list_head slist; /* list of sessions registered with v9fs */
struct rw_semaphore rename_sem;
long session_lock_timeout; /* retry interval for blocking locks */
};
/* cache_validity flags */
#define V9FS_INO_INVALID_ATTR 0x01
struct v9fs_inode {
struct netfs_inode netfs; /* Netfslib context and vfs inode */
struct p9_qid qid;
unsigned int cache_validity;
struct p9_fid *writeback_fid;
struct mutex v_mutex;
};
static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
{
return container_of(inode, struct v9fs_inode, netfs.inode);
}
static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
{
#ifdef CONFIG_9P_FSCACHE
return netfs_i_cookie(&v9inode->netfs);
#else
return NULL;
#endif
}
static inline struct fscache_volume *v9fs_session_cache(struct v9fs_session_info *v9ses)
{
#ifdef CONFIG_9P_FSCACHE
return v9ses->fscache;
#else
return NULL;
#endif
}
extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
const char *dev_name, char *data);
extern void v9fs_session_close(struct v9fs_session_info *v9ses);
extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags);
extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
extern int v9fs_vfs_rename(struct mnt_idmap *idmap,
struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags);
extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
struct p9_fid *fid,
struct super_block *sb, int new);
extern const struct inode_operations v9fs_dir_inode_operations_dotl;
extern const struct inode_operations v9fs_file_inode_operations_dotl;
extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
extern const struct netfs_request_ops v9fs_req_ops;
extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
struct p9_fid *fid,
struct super_block *sb, int new);
/* other default globals */
#define V9FS_PORT 564
#define V9FS_DEFUSER "nobody"
#define V9FS_DEFANAME ""
#define V9FS_DEFUID KUIDT_INIT(-2)
#define V9FS_DEFGID KGIDT_INIT(-2)
static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
{
return inode->i_sb->s_fs_info;
}
static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
{
return dentry->d_sb->s_fs_info;
}
static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
{
return v9ses->flags & V9FS_PROTO_2000U;
}
static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
{
return v9ses->flags & V9FS_PROTO_2000L;
}
/**
* v9fs_get_inode_from_fid - Helper routine to populate an inode by
* issuing a attribute request
* @v9ses: session information
* @fid: fid to issue attribute request for
* @sb: superblock on which to create inode
*
*/
static inline struct inode *
v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
struct super_block *sb)
{
if (v9fs_proto_dotl(v9ses))
return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
else
return v9fs_inode_from_fid(v9ses, fid, sb, 0);
}
/**
* v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
* issuing a attribute request
* @v9ses: session information
* @fid: fid to issue attribute request for
* @sb: superblock on which to create inode
*
*/
static inline struct inode *
v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
struct super_block *sb)
{
if (v9fs_proto_dotl(v9ses))
return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
else
return v9fs_inode_from_fid(v9ses, fid, sb, 1);
}
#endif
Reference in New Issue View Git Blame Copy Permalink