Re: [PATCH 5/6] nfs: check all iov segments for correct memory accessrights

From: Chuck Lever
Date: Fri May 19 2006 - 15:40:26 EST

Andrew Morton wrote:
+ if (unlikely(!access_ok(type, buf, len))) {
+ retval = -EFAULT;
+ goto out;
+ }

Now what's up here? Why does NFS, at this level, care about the page's
virtual address? get_user_pages() will handle that?

I guess I'm not clear on what behavior is desired for scatter/gather if one of the segments in an iov fails.

If one of the iov's will cause an EFAULT, how is that reported back to the application, and what happens to the I/O being requested in the other segments of the vector? When do we use an "all or nothing" semantic, and when is it OK for some segments to fail?

corporate: cel at netapp dot com
personal: chucklever at bigfoot dot com
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