On Tue, Dec 05, 2006 at 09:55:16AM -0500, Trond Myklebust wrote: > > The again statlite and > > readdirplus really are the most sane bits of these proposals as they > > fit nicely into the existing set of APIs. The filehandle idiocy on > > the other hand is way of into crackpipe land. > > ... > > a) networked filesystem specific. The mask stuff etc adds no > value whatsoever to actual "posix" filesystems. In fact it is > telling the kernel that it can violate posix semantics. I don't see what's network filesystem specific about it. Correct me if I'm wrong, but today ls -l on a local filesystem will first do readdir and then n stat calls. In the worst case scenario this will generate n+1 disk seeks. Local filesystems go through a lot of trouble to try to make the disk layout of the directory entries and the inodes optimal so that readahead and caching reduces the number of seeks. With readdirplus on the other hand, the filesystem would be able to send all the requests to the block layer and it would be free to optimize through disk elevators and what not. And this is not simply an "ls -l" optimization. Allthough I can no loger remember why, I think this is exactly what imap servers are doing when opening up big imap folders stored in maildir. -- Ragnar Kjørstad Software Engineer Scali - http://www.scali.com Scaling the Linux Datacenter - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
