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

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

Sorry, I just looked at my inbox.

Delete in parallel from one node while ref count of the file is still
+ve on another is an issue which we chose not to handle because these
are complex problems in distributed filesystems.

When fuse_lowlevel_notify_inval_entry is called from userspace it
seems to hang each and every time. Am I missing something ?

Thanks,
Satya.

On Thu, Aug 2, 2018 at 1:39 AM, Nikolaus Rath <Nik...@ra...> wrote:
> Hi,
>
> I replied to you on the same day..
>
> Best,
> -Nikolaus
>
> On Aug 01 2018, Satya Prakash GS <g.s...@gm...> wrote:
>> 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.
>>
>> ------------------------------------------------------------------------------
>> Check out the vibrant tech community on one of the world's most
>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>> --
>> fuse-devel mailing list
>> To unsubscribe or subscribe, visit https://lists.sourceforge.net/lists/listinfo/fuse-devel
>
>
> --
> GPG Fingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F
>
>              »Time flies like an arrow, fruit flies like a Banana.«