Re: [fuse-devel] backpressure on inode cache?

[Miklos S. <mi...@sz...>]

Sage Weil <sa...@in...> writes:

> Hi-
>
> Is there a way through the lowlevel fuse interface to exhert some sort
> of backpressure on the inode cache size?  Currently ceph-fuse client
> references to inodes pin some server-side state and I'd like to
> communicate the backpressure the server is already communicating to
> the client thru fuse to shrink the number of inodes the VFS is holding
> on to.
>
> I'm assuming that simply dropping inodes without getting a fuse forget
> call will lead to various forms of ESTALE-like badness when a getattr
> or similar request comes through down the line.

You can purge individual dentries/inodes from the cache with
fuse_lowlevel_notify_inval_entry().

There's no mechanism currently to put pressure on the inode/dentry
caches with fuse.

Thanks,
Miklos