Re: [PATCH] Re: zero-filed page on VOP_PUTPAGES

[manu%netbsd.org@localhost (Emmanuel Dreyfus)]

YAMAMOTO Takashi <yamt%mwd.biglobe.ne.jp@localhost> wrote:

> i don't think it fixes the problem as VOPs can release the lock
> before the completion of async PUFFS_VN_SETATTR.

It just prevents puffs_vnop_getattr to call uvm_vnp_setattr with a stall
value between the time dosetattr sends PUFFS_VN_SETATTR and the time it
calls uvm_vnp_setattr. This is enough to work around the issue if the
file server does not reorder requests.

> besides that, non-diagnostic uses of VOP_ISLOCKED are mostly considered bugs.

The problem is that VOP_GETATTR does not specify whether the vnode
should be locked or not. Some callers lock and others do not, therefore
the test.

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu%netbsd.org@localhost