[ 3.5.y.z extended stable ] Patch "NFSv4: don't put ACCESS in OPEN compound if O_EXCL" has been added to staging queue

[Herton Ronaldo Krzesinski]

This is a note to let you know that I have just added a patch titled

    NFSv4: don't put ACCESS in OPEN compound if O_EXCL

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From 01fe6296b9dcdc0d3985ef2dca298c4ef8ba59bd Mon Sep 17 00:00:00 2001
From: Weston Andros Adamson <dros at netapp.com>
Date: Tue, 2 Oct 2012 14:49:52 -0700
Subject: [PATCH] NFSv4: don't put ACCESS in OPEN compound if O_EXCL

commit ae2bb03236fc978bdf673c19d39832500793b83c upstream.

Don't put an ACCESS op in OPEN compound if O_EXCL, because ACCESS
will return permission denied for all bits until close.

Fixes a regression due to commit 6168f62c (NFSv4: Add ACCESS operation to
OPEN compound)

Signed-off-by: Weston Andros Adamson <dros at netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust at netapp.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 fs/nfs/nfs4proc.c       |   12 +++++++++---
 fs/nfs/nfs4xdr.c        |   12 ++++++++----
 include/linux/nfs_xdr.h |    1 +
 3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 4ecc047..6bc11de 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -859,9 +859,15 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
 	p->o_arg.fh = NFS_FH(dir);
 	p->o_arg.open_flags = flags;
 	p->o_arg.fmode = fmode & (FMODE_READ|FMODE_WRITE);
-	/* ask server to check for all possible rights as results are cached */
-	p->o_arg.access = NFS4_ACCESS_READ | NFS4_ACCESS_MODIFY |
-			  NFS4_ACCESS_EXTEND | NFS4_ACCESS_EXECUTE;
+	/* don't put an ACCESS op in OPEN compound if O_EXCL, because ACCESS
+	 * will return permission denied for all bits until close */
+	if (!(flags & O_EXCL)) {
+		/* ask server to check for all possible rights as results
+		 * are cached */
+		p->o_arg.access = NFS4_ACCESS_READ | NFS4_ACCESS_MODIFY |
+				  NFS4_ACCESS_EXTEND | NFS4_ACCESS_EXECUTE;
+		p->o_res.access_request = p->o_arg.access;
+	}
 	p->o_arg.clientid = server->nfs_client->cl_clientid;
 	p->o_arg.id.create_time = ktime_to_ns(sp->so_seqid.create_time);
 	p->o_arg.id.uniquifier = sp->so_seqid.owner_id;
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 0a040cf..82855f6 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2226,7 +2226,8 @@ static void nfs4_xdr_enc_open(struct rpc_rqst *req, struct xdr_stream *xdr,
 	encode_putfh(xdr, args->fh, &hdr);
 	encode_open(xdr, args, &hdr);
 	encode_getfh(xdr, &hdr);
-	encode_access(xdr, args->access, &hdr);
+	if (args->access)
+		encode_access(xdr, args->access, &hdr);
 	encode_getfattr_open(xdr, args->bitmask, args->open_bitmap, &hdr);
 	encode_nops(&hdr);
 }
@@ -2263,7 +2264,8 @@ static void nfs4_xdr_enc_open_noattr(struct rpc_rqst *req,
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, args->fh, &hdr);
 	encode_open(xdr, args, &hdr);
-	encode_access(xdr, args->access, &hdr);
+	if (args->access)
+		encode_access(xdr, args->access, &hdr);
 	encode_getfattr(xdr, args->bitmask, &hdr);
 	encode_nops(&hdr);
 }
@@ -6271,7 +6273,8 @@ static int nfs4_xdr_dec_open(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
 	status = decode_getfh(xdr, &res->fh);
 	if (status)
 		goto out;
-	decode_access(xdr, &res->access_supported, &res->access_result);
+	if (res->access_request)
+		decode_access(xdr, &res->access_supported, &res->access_result);
 	decode_getfattr(xdr, res->f_attr, res->server);
 out:
 	return status;
@@ -6320,7 +6323,8 @@ static int nfs4_xdr_dec_open_noattr(struct rpc_rqst *rqstp,
 	status = decode_open(xdr, res);
 	if (status)
 		goto out;
-	decode_access(xdr, &res->access_supported, &res->access_result);
+	if (res->access_request)
+		decode_access(xdr, &res->access_supported, &res->access_result);
 	decode_getfattr(xdr, res->f_attr, res->server);
 out:
 	return status;
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index ccc24e0..65d8e69 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -370,6 +370,7 @@ struct nfs_openres {
 	struct nfs4_string	*owner;
 	struct nfs4_string	*group_owner;
 	struct nfs4_sequence_res	seq_res;
+	__u32			access_request;
 	__u32			access_supported;
 	__u32			access_result;
 };
--
1.7.9.5