Re: MPSAFE VFS -- List of upcoming actions

From: Garrett Cooper <yanegomi_at_gmail.com>
Date: Wed, 25 Jul 2012 12:46:39 -0700
On Wed, Jul 25, 2012 at 10:04 AM, Attilio Rao <attilio_at_freebsd.org> wrote:
> On 7/21/12, Antony Mawer <lists_at_mawer.org> wrote:
>> On Wed, Jul 18, 2012 at 6:45 PM, Attilio Rao <attilio_at_freebsd.org> wrote:
>>> 2012/7/18, Gustau Pérez i Querol <gperez_at_entel.upc.edu>:
>>>>
>>>>     Sorry fo the delay.
>>>>
>>>>     About the ntfs support, I'd go with fuse and leave the most relevant
>>>> filesystems in kernel space. In fact filesystems not particulary
>>>> specific and not tied our kernel would go to userspace; thinks like
>>>> smbfs, nwfs, ntfs, ext2 o ext4 for example should be in userspace (the
>>>> list is incomplete and I don't really know if all of them are yet
>>>> implemenent in userspace) in my opinion. That would make them easier to
>>>> maintain (changes in the kernel would only affect fuse, once fixed all
>>>> the userspace filesystem would work again).
>>>>
>>>>     As a bonus, we would get many working fs based on fuse. In the
>>>> server side gluster is a desirable thing; in the desktop things like
>>>> gvfs (in the linux world gvfs is used not only by gnome but also by kde
>>>> or xfce) or truecrypt
>>>
>>> I'm really concerned also about ntfs and smbfs at the moment. It seems
>>> that there is also a FUSE smbfs port, but I never used it and I'm not
>>> sure about its state at all.
>>
>> From what I understand, Apple have done a considerable amount of work
>> on the FreeBSD-drived smbfs in the latest versions of OS X, based on
>> the existing smbfs in tree:
>
> I've also found that there are 2 FUSE modules for smbfs but pho_at_ and
> flo_at_ still haven't tested them. It may make sense to do so before we
> commit FUSE to -CURRENT. However, thee is a plan by a $COMPANY to work
> on the in-kernel version of smbfs and lock it before 10.0 is shipped.
> In the unlikely events this doesn't happen we will came up with a
> different plan (assuming we will adopt anyway the FUSE module, if it
> proves to work well).
>
>>     http://www.opensource.apple.com/source/smb/smb-552.5/
>>
>> I imagine things like the filesystem locking are probably somewhat
>> different, but in terms of updating smbfs itself to support newer
>> features it may be a good base (licensing permitting). smbfs at the
>> moment lacks in some areas such as DFS support, although I do not know
>> if the OS X version is any different there (given the consumer focus
>> of their OS, probably not). There was also a version spun off by
>> OpenSolaris:
>>
>>     http://hub.opensolaris.org/bin/view/Project+smbfs/
>>
>> which again was based on the FreeBSD + Apple versions.
>>
>> I also have a vested interest in NWFS continuing to work - only from a
>> legacy point of view where we still interoperate with a number of
>> Netware 6 servers through this. While those will likely eventually go
>> away, more than likely before we move to 10.x, if there is anyone
>> capable of working on it we could supply a test environment.
>> Unfortunately the actual locking of the NWFS and NCP modules is
>> outside my sphere of knowledge...
>
> If you have NCP, do you think you can try this netncp I never
> committed because lack of testing?:
> http://lists.freebsd.org/pipermail/freebsd-fs/2009-January/005617.html
>
> IIRC, Apple does a similar thing for netsmb (which suffers from a
> similar problem as netncp).
> Do you know if FUSE can support NWFS in any way?
>
> Starting providing stress-tests on the current codebase for
> NWFS/NetNCP (and report bugs found, preparing a list) could be a good
> way to start the locking effort. Interested developers then can look
> into such a list and provide necessary insight.

1. The in-kernel smbfs is so far behind the SMB spec that I'm not sure
that it's worthwhile maintaining it. It's SMB1.x based, which is
pre-Vista; SMB2.1 has been out for a while and 3.0 is rolling around
the corner in the next couple years (about the same time Windows XP is
going to be EOS).
2. According to reports I have from internal sources, the Apple
implementation is suboptimal from a performance perspective, in part
because the Apple SMB client doesn't coalesce requests. I concur on
the poor performance based on personal experience because NFS beats
SMB hands down on OSX (comes close to saturating the physical media
with NFS, and putters along at a fraction of the link speed with CIFS
on my Macbook Pro with Lion), whereas running a Windows 7 client
against samba36 yields performance I would expect (saturates gigabit).

YMMV,
-Garrett

1. http://windows.microsoft.com/en-us/windows/products/lifecycle
Received on Wed Jul 25 2012 - 17:46:41 UTC

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