From: Trond Myklebust <trond.myklebust@fys.uio.no>
Subject: Re: 2.5: NFS troubles
Date: Mon, 7 Apr 2003 15:23:59 +0200
Sender: linux-kernel-owner@vger.kernel.org
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To: Robert Love <rml@tech9.net>, Siim Vahtre <siim@pld.ttu.ee>
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OK. I've managed to squash the NFS read corruption problems that I had
on my 2.5.x client setup with the following patch.
Since the two of you reported what appears to be the same problem,
would you mind trying it out?

The fix basically tightens up consistency checks in the process of
reading the skb (which is done in the sk->data_ready() callback).

Cheers,
  Trond

diff -u --recursive --new-file linux-2.5.66-10-nr_dirty/net/sunrpc/xprt.c linux-2.5.66-11-fix_read/net/sunrpc/xprt.c
--- linux-2.5.66-10-nr_dirty/net/sunrpc/xprt.c	2003-03-27 18:34:08.000000000 +0100
+++ linux-2.5.66-11-fix_read/net/sunrpc/xprt.c	2003-04-07 15:15:29.000000000 +0200
@@ -625,7 +625,8 @@
 {
 	if (len > desc->count)
 		len = desc->count;
-	skb_copy_bits(desc->skb, desc->offset, to, len);
+	if (skb_copy_bits(desc->skb, desc->offset, to, len))
+		return 0;
 	desc->count -= len;
 	desc->offset += len;
 	return len;
@@ -669,11 +670,15 @@
 		csum2 = skb_checksum(skb, desc.offset, skb->len - desc.offset, 0);
 		desc.csum = csum_block_add(desc.csum, csum2, desc.offset);
 	}
+	if (desc.count)
+		return -1;
 	if ((unsigned short)csum_fold(desc.csum))
 		return -1;
 	return 0;
 no_checksum:
 	xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_bits);
+	if (desc.count)
+		return -1;
 	return 0;
 }
 
@@ -750,7 +755,8 @@
 {
 	if (len > desc->count)
 		len = desc->count;
-	skb_copy_bits(desc->skb, desc->offset, p, len);
+	if (skb_copy_bits(desc->skb, desc->offset, p, len))
+		return 0;
 	desc->offset += len;
 	desc->count -= len;
 	return len;