2009-04-15 14:11:08

by Suresh Jayaraman

Subject: [PATCH] NFS: Fix send buffer length calculation in nfs3_xdr_setaclargs()

The recent posixacl fix(commit ae46141ff08f1965b17c531b571953c39ce8b9e2)
seems to have introduced a bug that will lead to -EINVAL errors during
normal setfacl operations on file or dir. This patch attempts to fix
this.

Signed-off-by: Suresh Jayaraman <[email protected]>
---

diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index e6a1932..7cd0069 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -702,18 +702,19 @@ nfs3_xdr_setaclargs(struct rpc_rqst *req, __be32 *p,
struct nfs3_setaclargs *args)
{
struct xdr_buf *buf = &req->rq_snd_buf;
- unsigned int base;
+ unsigned int base, len;
+ unsigned int len_in_head = 2 * (2 + 3 * NFS_ACL_MAX_ENTRIES_INLINE);
int err;

p = xdr_encode_fhandle(p, NFS_FH(args->inode));
*p++ = htonl(args->mask);
- req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
- base = req->rq_slen;
+ len = xdr_adjust_iovec(req->rq_svec, p);
+ base = len;
+ len -= len_in_head;
+ req->rq_slen = xdr_adjust_iovec(req->rq_svec, p + (len >> 2));

if (args->npages != 0)
- xdr_encode_pages(buf, args->pages, 0, args->len);
- else
- req->rq_slen += args->len;
+ xdr_encode_pages(buf, args->pages, 0, len);

err = nfsacl_encode(buf, base, args->inode,
(args->mask & NFS_ACL) ?

2009-04-15 18:25:10

by Myklebust, Trond

Subject: Re: [PATCH] NFS: Fix send buffer length calculation in nfs3_xdr_setaclargs()

On Wed, 2009-04-15 at 19:40 +0530, Suresh Jayaraman wrote:
> The recent posixacl fix(commit ae46141ff08f1965b17c531b571953c39ce8b9e2)
> seems to have introduced a bug that will lead to -EINVAL errors during
> normal setfacl operations on file or dir. This patch attempts to fix
> this.

To start with, your len_in_head is in units of 32-bit _words_, whereas
len, base, and req->rq_slen are in units of bytes.

Then, 'len' is initialised to the length of the currently encoded part
of the RPC header before subtracting 'len_in_head'. The resulting number
is then used both as the length of the page array, and to extend the
length of the req->rq_svec??? That makes absolutely no sense...


Please check if the following patch fixes things for you.

Trond
------------------------------------------------------------
>From b273b42f8b793a4a446015b50a5c1473553af48b Mon Sep 17 00:00:00 2001
From: Trond Myklebust <[email protected]>
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 <[email protected]>
---
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) ?
--
1.6.0.4


--
Trond Myklebust
Linux NFS client maintainer

NetApp
[email protected]
http://www.netapp.com