Re: [PATCHSET] FUSE: extend FUSE to support more operations

[Tejun Heo <tj@kernel.org>]

Miklos Szeredi wrote:
> On Wed, 12 Nov 2008, Tejun Heo wrote:
>>> Comments about the others:
>>>
>>>   0002-FUSE-pass-nonblock-flag-to-client.patch
>>>
>>> this is not needed, f_flags are already passed to userspace for read
>>> and write.
>> Hmmm... I'll try to find out whether I can use f_flags.  There was
>> something that prevented it from working properly.  I'll dig.
> 
> Support for this was missing from libfuse, but now I fixed that in the
> CVS version.

Yeah, right, it can just use fi.flags.  0002 dropped.

>>>   0004-FUSE-implement-direct-lseek-support.patch
>>>
>>> this is trickier to get the interface right I think.  If we want to
>>> allow filesystems to implement a custom lseek, then we also want them
>>> to keep track of the file position, which means we must differentiate
>>> between a write(2) and a pwrite(2) and similarly for reads.  AFAICS
>>> this isn't needed for CUSE so we can leave this to later.
>> Read/write already passes @offset, so the only thing required is an
>> extra flag there.  I mainly wanted a way for a CUSE server to veto lseek
>> with proper error and still think it's better to have this as we don't
>> really know what wacky users are out there.  What do you think about an
>> extra flag?
> 
> OK, but that's gonna involve a fair bit of API churn, and I'm not sure
> it's worth it at this stage.  If this is not needed for the OSS
> emulation, I think we should postpone it.

Alright.

Thanks.

-- 
tejun