From: Olga Kornievskaia <kolga@netapp.com>
Date: Fri, 16 Oct 2020 09:25:45 -0400
Subject: [PATCH] NFSv4.2: support EXCHGID4_FLAG_SUPP_FENCE_OPS 4.2 EXCHANGE_ID
 flag
Git-commit: 8c39076c276be0b31982e44654e2c2357473258a
Patch-mainline: v5.10
References: git-fixes

RFC 7862 introduced a new flag that either client or server is
allowed to set: EXCHGID4_FLAG_SUPP_FENCE_OPS.

Client needs to update its bitmask to allow for this flag value.

V2: changed minor version argument to unsigned int

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/nfs4proc.c         |    9 ++++++---
 include/uapi/linux/nfs4.h |    3 +++
 2 files changed, 9 insertions(+), 3 deletions(-)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7301,9 +7301,11 @@ int nfs4_proc_secinfo(struct inode *dir,
  * both PNFS and NON_PNFS flags set, and not having one of NON_PNFS, PNFS, or
  * DS flags set.
  */
-static int nfs4_check_cl_exchange_flags(u32 flags)
+static int nfs4_check_cl_exchange_flags(u32 flags, u32 version)
 {
-	if (flags & ~EXCHGID4_FLAG_MASK_R)
+	if (version >= 2 && (flags & ~EXCHGID4_2_FLAG_MASK_R))
+		goto out_inval;
+	else if (version < 2 && (flags & ~EXCHGID4_FLAG_MASK_R))
 		goto out_inval;
 	if ((flags & EXCHGID4_FLAG_USE_PNFS_MDS) &&
 	    (flags & EXCHGID4_FLAG_USE_NON_PNFS))
@@ -7580,7 +7582,8 @@ static void nfs4_exchange_id_done(struct
 	trace_nfs4_exchange_id(clp, status);
 
 	if (status == 0)
-		status = nfs4_check_cl_exchange_flags(cdata->res.flags);
+		status = nfs4_check_cl_exchange_flags(cdata->res.flags,
+						      clp->cl_mvops->minor_version);
 
 	if (cdata->xprt && status == 0) {
 		status = nfs4_detect_session_trunking(clp, &cdata->res,
--- a/include/uapi/linux/nfs4.h
+++ b/include/uapi/linux/nfs4.h
@@ -135,6 +135,8 @@
 
 #define EXCHGID4_FLAG_UPD_CONFIRMED_REC_A	0x40000000
 #define EXCHGID4_FLAG_CONFIRMED_R		0x80000000
+
+#define EXCHGID4_FLAG_SUPP_FENCE_OPS		0x00000004
 /*
  * Since the validity of these bits depends on whether
  * they're set in the argument or response, have separate
@@ -142,6 +144,7 @@
  */
 #define EXCHGID4_FLAG_MASK_A			0x40070103
 #define EXCHGID4_FLAG_MASK_R			0x80070103
+#define EXCHGID4_2_FLAG_MASK_R			0x80070107
 
 #define SEQ4_STATUS_CB_PATH_DOWN		0x00000001
 #define SEQ4_STATUS_CB_GSS_CONTEXTS_EXPIRING	0x00000002