From e03abc0c963a31cb07dfbc07c7d85d75e0d13cf4 Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Sun, 11 Feb 2007 13:21:39 -0600 Subject: 9p: implement optional loose read cache While cacheing is generally frowned upon in the 9p world, it has its place -- particularly in situations where the remote file system is exclusive and/or read-only. The vacfs views of venti content addressable store are a real-world instance of such a situation. To facilitate higher performance for these workloads (and eventually use the fscache patches), we have enabled a "loose" cache mode which does not attempt to maintain any form of consistency on the page-cache or dcache. This results in over two orders of magnitude performance improvement for cacheable block reads in the Bonnie benchmark. The more aggressive use of the dcache also seems to improve metadata operational performance. Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_dentry.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'fs/9p/vfs_dentry.c') diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c index 062daa6000a..ddffd8aa902 100644 --- a/fs/9p/vfs_dentry.c +++ b/fs/9p/vfs_dentry.c @@ -53,9 +53,30 @@ static int v9fs_dentry_delete(struct dentry *dentry) { dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry); + return 1; } +/** + * v9fs_cached_dentry_delete - called when dentry refcount equals 0 + * @dentry: dentry in question + * + * Only return 1 if our inode is invalid. Only non-synthetic files + * (ones without mtime == 0) should be calling this function. + * + */ + +static int v9fs_cached_dentry_delete(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry); + + if(!inode) + return 1; + + return 0; +} + /** * v9fs_dentry_release - called when dentry is going to be freed * @dentry: dentry that is being release @@ -87,6 +108,11 @@ void v9fs_dentry_release(struct dentry *dentry) } } +struct dentry_operations v9fs_cached_dentry_operations = { + .d_delete = v9fs_cached_dentry_delete, + .d_release = v9fs_dentry_release, +}; + struct dentry_operations v9fs_dentry_operations = { .d_delete = v9fs_dentry_delete, .d_release = v9fs_dentry_release, -- cgit v1.2.3