Re: Problems with default ACLs over NFS

[Suresh Jayaraman <sjayaraman@suse.de>]

hooanon05@yahoo.co.jp wrote:
>> On Mon, 23 Mar 2009 22:24:27 +0100 "J.A. Magall__n" <jamagallon@ono.com> wrote:
>>
>>> Hi all...
>>>
>>> I have a strange problem with 2.6.29-rc8-git3.
>>> It looks like a kernel bug... ?
>>>
>>> I have a box with NFS autofs-mounted home directories. Server is a
>>> Solaris 10 system. This worked in previous kernel versions, so I
>>> don't blame Solaris, at this moment.
>>>
>>> With this acls set in my home:
> 	:::
>>> I get this strange message in the linux client:
>>>
>>> cicely:~> mkdir kk  
>>> mkdir: cannot create directory `kk': Invalid argument

The following patch from Trond should fix this issue, I think.


From: Trond Myklebust <Trond.Myklebust@netapp.com>
Date: Wed, 15 Apr 2009 13:58:45 -0400
Subject: [PATCH] NFS: Fix the XDR iovec calculation in nfs3_xdr_setaclargs

Commit ae46141ff08f1965b17c531b571953c39ce8b9e2 (NFSv3: Fix posix ACL code)
introduces a bug in the calculation of the XDR header iovec. In the case
where we are inlining the acls, we need to adjust the length of the iovec
req->rq_svec, in addition to adjusting the total buffer length.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---
 fs/nfs/nfs3xdr.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index e6a1932..35869a4 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -713,7 +713,8 @@ nfs3_xdr_setaclargs(struct rpc_rqst *req, __be32 *p,
 	if (args->npages != 0)
 		xdr_encode_pages(buf, args->pages, 0, args->len);
 	else
-		req->rq_slen += args->len;
+		req->rq_slen = xdr_adjust_iovec(req->rq_svec,
+				p + XDR_QUADLEN(args->len));
 
 	err = nfsacl_encode(buf, base, args->inode,
 			    (args->mask & NFS_ACL) ?



> Tracing some kernel functions, I observed several thigs.
> - xdr_buf_subsegment() returned -1 due to 'len' is not 0.
> - xdr_encode_word() call from nfsacl_encode() got this -1, and
>   nfsacl_encode/nfs3_xdr_setaclargs/nfs3_proc_setacls/nfs3_proc_setacl/nfs3_setxattr
>   returned -EINVAL.
> 
> 
> Finally I am afraid this commit might be related to this issue.
> 
> commit ae46141ff08f1965b17c531b571953c39ce8b9e2
> Author: Trond Myklebust <Trond.Myklebust@netapp.com>
> Date:   Tue Mar 10 20:33:18 2009 -0400
> 
>     NFSv3: Fix posix ACL code
>     
>     Fix a memory leak due to allocation in the XDR layer. In cases where the
>     RPC call needs to be retransmitted, we end up allocating new pages without
>     clearing the old ones. Fix this by moving the allocation into
>     nfs3_proc_setacls().
>     
>     Also fix an issue discovered by Kevin Rudd, whereby the amount of memory
>     reserved for the acls in the xdr_buf->head was miscalculated, and causing
>     corruption.
> 
> 
> 
> J. R. Okajima
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-- 
Suresh Jayaraman