mirror of
https://github.com/torvalds/linux.git
synced 2024-12-23 11:21:33 +00:00
60e78d2c99
This patch adds a persistent, read-only caching facility for 9p clients using the FS-Cache caching backend. When the fscache facility is enabled, each inode is associated with a corresponding vcookie which is an index into the FS-Cache indexing tree. The FS-Cache indexing tree is indexed at 3 levels: - session object associated with each mount. - inode/vcookie - actual data (pages) A cache tag is chosen randomly for each session. These tags can be read off /sys/fs/9p/caches and can be passed as a mount-time parameter to re-attach to the specified caching session. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
128 lines
4.2 KiB
C
128 lines
4.2 KiB
C
/*
|
|
* V9FS definitions.
|
|
*
|
|
* Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
|
|
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2
|
|
* as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to:
|
|
* Free Software Foundation
|
|
* 51 Franklin Street, Fifth Floor
|
|
* Boston, MA 02111-1301 USA
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* enum p9_session_flags - option flags for each 9P session
|
|
* @V9FS_EXTENDED: whether or not to use 9P2000.u 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_ANY: use a single attach for all users
|
|
* @V9FS_ACCESS_MASK: bit mask of different ACCESS options
|
|
*
|
|
* Session flags reflect options selected by users at mount time
|
|
*/
|
|
enum p9_session_flags {
|
|
V9FS_EXTENDED = 0x01,
|
|
V9FS_ACCESS_SINGLE = 0x02,
|
|
V9FS_ACCESS_USER = 0x04,
|
|
V9FS_ACCESS_ANY = 0x06,
|
|
V9FS_ACCESS_MASK = 0x06,
|
|
};
|
|
|
|
/* 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_LOOSE,
|
|
CACHE_FSCACHE,
|
|
};
|
|
|
|
/**
|
|
* 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
|
|
* @options: copy of options string given by user
|
|
* @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_cookie *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 */
|
|
unsigned int dfltuid; /* default uid/muid for legacy support */
|
|
unsigned int dfltgid; /* default gid for legacy support */
|
|
u32 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 p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
|
|
char *);
|
|
void v9fs_session_close(struct v9fs_session_info *v9ses);
|
|
void v9fs_session_cancel(struct v9fs_session_info *v9ses);
|
|
|
|
#define V9FS_MAGIC 0x01021997
|
|
|
|
/* other default globals */
|
|
#define V9FS_PORT 564
|
|
#define V9FS_DEFUSER "nobody"
|
|
#define V9FS_DEFANAME ""
|
|
#define V9FS_DEFUID (-2)
|
|
#define V9FS_DEFGID (-2)
|
|
|
|
static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
|
|
{
|
|
return (inode->i_sb->s_fs_info);
|
|
}
|
|
|
|
static inline int v9fs_extended(struct v9fs_session_info *v9ses)
|
|
{
|
|
return v9ses->flags & V9FS_EXTENDED;
|
|
}
|