Re: CVS commit: [yamt-nfs-mp] src/sys

[yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)]

> On Wed, Jun 24, 2009 at 02:21:44PM +0000, YAMAMOTO Takashi wrote:
>> Module Name: src
>> Committed By:        yamt
>> Date:                Wed Jun 24 14:21:44 UTC 2009
>> 
>> Modified Files:
>>      src/sys/kern [yamt-nfs-mp]: vfs_syscalls.c
>>      src/sys/nfs [yamt-nfs-mp]: nfs_vfsops.c nfs_vnops.c
>> 
>> Log Message:
>> lock vnode when calling VOP_GETATTR because there's no reasonable way for
>> an implementation of VOP_GETATTR to prevent the vnode from being revoked.
> 
> I've not looked at the specific code, but surely a reference count is enough?
> Requiring callers to lock vnodes doesn't seem right to me - since it
> is only likely to cause locking violations in layered fs.
> 
> The fact that the caller has a reference to the vnode at all should
> really be enough, surely??

do you mean vref?
it doesn't prevent revoke(2).
thus a filesystem can't access v_data safely.

YAMAMOTO Takashi

> 
>       David
> 
> -- 
> David Laight: david%l8s.co.uk@localhost