From 60e78d2c993e58d890596d951fff77d5965adcd6 Mon Sep 17 00:00:00 2001 From: Abhishek Kulkarni Date: Wed, 23 Sep 2009 13:00:27 -0500 Subject: 9p: Add fscache support to 9p 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 Signed-off-by: Eric Van Hensbergen --- fs/9p/v9fs.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'fs/9p/v9fs.h') diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h index 38762bf102a..019f4ccb70c 100644 --- a/fs/9p/v9fs.h +++ b/fs/9p/v9fs.h @@ -51,6 +51,7 @@ enum p9_session_flags { enum p9_cache_modes { CACHE_NONE, CACHE_LOOSE, + CACHE_FSCACHE, }; /** @@ -60,6 +61,8 @@ enum p9_cache_modes { * @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 @@ -68,7 +71,7 @@ enum p9_cache_modes { * @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 - * @debugfs_dir: reference to debugfs_dir which can be used for add'l debug + * @slist: reference to list of registered 9p sessions * * This structure holds state for each session instance established during * a sys_mount() . @@ -84,6 +87,10 @@ struct v9fs_session_info { 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 */ @@ -92,11 +99,9 @@ struct v9fs_session_info { 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 dentry *debugfs_dir; + struct list_head slist; /* list of sessions registered with v9fs */ }; -extern struct dentry *v9fs_debugfs_root; - struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *, char *); void v9fs_session_close(struct v9fs_session_info *v9ses); -- cgit v1.2.3