Re: [fuse-devel] reg. generation number and inode reuse

[Satya P. GS <g.s...@gm...>]

Can somebody please reply to this.

Thanks,
Satya.

On Wed, Jul 18, 2018 at 1:42 PM, Satya Prakash GS
<g.s...@gm...> wrote:
> Hi,
>
> Ours is a distributed filesystem and we are using fuse to access our
> filesystem locally.
> Inode numbers in our filesystem get reused, however our filesystem has
> a concept similar to generation number which gets bumped up on every
> reuse. Our inode numbers are bigger than 8-bytes and we coulnd't
> squeeze in the generation number into the ino that we serve fuse
> kernel.
>
> Inode numbers created by one fuse node could potentially be deleted by
> the other node. This leads to EBUSY errors in mkdir (mkdir does "do I
> know this inode check. If kernel thinks it knows this inode then it
> complains that the inode is busy"). One way to fix this issue is by
> maintaining a replica of the kernel dentry cache in our userspace.
> Every time I serve the inode I should first check if this inode exists
> in the userspace cache and if it does, then do
> fuse_lowlevel_notify_inval_entry on that dentry. However, things could
> get a lot simpler if the generation number served in mkdir is used in
> resolving conflicts in kernel. Is this already addressed. If so,
> kindly tell me which release has this fix. We are currently in 2.7 and
> we cherry-picked few fixes from 2.9.
>
> Thanks,
> Satya.