From: ASANO Masahiro I'm trying to speeding up mkdir(2) for network file systems. A typical mkdir(2) calls two inode_operations: lookup and mkdir. The lookup operation would fail with ENOENT in common case. I think it is unnecessary because the subsequent mkdir operation can check it. In case of creat(2), lookup operation is called with the LOOKUP_CREATE flag, so individual filesystem can omit real lookup. e.g. nfs_lookup(). Here is a sample patch which uses LOOKUP_CREATE and O_EXCL on mkdir, symlink and mknod. This uses the gadget for creat(2). And here is the result of a benchmark on NFSv3. mkdir(2) 10,000 times: original 50.5 sec patched 29.0 sec Signed-off-by: ASANO Masahiro Signed-off-by: Andrew Morton --- fs/namei.c | 2 ++ 1 file changed, 2 insertions(+) diff -puN fs/namei.c~add-lookup-hint-for-network-file-systems fs/namei.c --- a/fs/namei.c~add-lookup-hint-for-network-file-systems +++ a/fs/namei.c @@ -1759,6 +1759,8 @@ struct dentry *lookup_create(struct name if (nd->last_type != LAST_NORM) goto fail; nd->flags &= ~LOOKUP_PARENT; + nd->flags |= LOOKUP_CREATE; + nd->intent.open.flags = O_EXCL; /* * Do the final lookup. _