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_inode.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 5cf22134826b..124a085d1f2e 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -504,7 +504,10 @@ v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode, goto error; } - dentry->d_op = &v9fs_dentry_operations; + if(v9ses->cache) + dentry->d_op = &v9fs_cached_dentry_operations; + else + dentry->d_op = &v9fs_dentry_operations; d_instantiate(dentry, inode); if (nd && nd->flags & LOOKUP_OPEN) { @@ -589,7 +592,10 @@ static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) goto error; } - dentry->d_op = &v9fs_dentry_operations; + if(v9ses->cache) + dentry->d_op = &v9fs_cached_dentry_operations; + else + dentry->d_op = &v9fs_dentry_operations; d_instantiate(dentry, inode); return 0; @@ -626,7 +632,6 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, sb = dir->i_sb; v9ses = v9fs_inode2v9ses(dir); - dentry->d_op = &v9fs_dentry_operations; dirfid = v9fs_fid_lookup(dentry->d_parent); if(IS_ERR(dirfid)) @@ -697,6 +702,10 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, fid->qid = fcall->params.rstat.stat.qid; v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb); + if((fid->qid.version)&&(v9ses->cache)) + dentry->d_op = &v9fs_cached_dentry_operations; + else + dentry->d_op = &v9fs_dentry_operations; d_add(dentry, inode); kfree(fcall); @@ -1184,7 +1193,10 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry, goto free_vfid; } - dentry->d_op = &v9fs_dentry_operations; + if(v9ses->cache) + dentry->d_op = &v9fs_cached_dentry_operations; + else + dentry->d_op = &v9fs_dentry_operations; d_instantiate(dentry, inode); return 0; -- cgit v1.2.3 From c959df9f01cfb2f43b4d1f58631ee1e9c50541b6 Mon Sep 17 00:00:00 2001 From: Latchesar Ionkov Date: Mon, 23 Apr 2007 14:41:11 -0700 Subject: v9fs: don't use primary fid when removing file v9fs_insert uses v9fs_fid_lookup (which also locks the fid) to get the primary fid associated with the dentry and destroys the v9fs_fid struct after removing the file. If another process called v9fs_fid_lookup on the same dentry, it may wait undefinitely for the fid's lock (as the struct is freed). This patch changes v9fs_remove to use a cloned fid, so the primary fid is not locked and freed. Signed-off-by: Latchesar Ionkov Cc: Eric Van Hensbergen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/9p/vfs_inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 124a085d1f2e..b01b0a457932 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -415,7 +415,7 @@ static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir) file_inode = file->d_inode; sb = file_inode->i_sb; v9ses = v9fs_inode2v9ses(file_inode); - v9fid = v9fs_fid_lookup(file); + v9fid = v9fs_fid_clone(file); if(IS_ERR(v9fid)) return PTR_ERR(v9fid); -- cgit v1.2.3