Re: [PATCH] [Request for inclusion] Filesystem in Userspace

Miklos Szeredi
2004-11-18T17:31:15Z

> A normal write is a VFS write() call, I assume. While they're going
> through the page cache, the pages are dirty, right? Is it possible that
> FUSE needs more real memory after dirtying those pages in order to finish
> cleaning them?

It's possible, but I don't see why that's a problem. If it can get
more memory it's OK. If allocation fails, then the write() will fail
with ENOMEM, if OOM killer get's to work and kills the FUSE process,
then write will return with ENOTCONN or something like that.

> What about the 3rd case: private writable mapping? How does that work?

That only reads pages and never writes them. It's just like malloc,
but prefilled with the file contents.

Miklos