[PATCH 4.14 095/125] NFSv4.2: support EXCHGID4_FLAG_SUPP_FENCE_OPS 4.2 EXCHANGE_ID flag

[Greg Kroah-Hartman]

From: Olga Kornievskaia <kolga@xxxxxxxxxx>

commit 8c39076c276be0b31982e44654e2c2357473258a upstream.

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@xxxxxxxxxx>
CC: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 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
@@ -7283,9 +7283,11 @@ 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))
@@ -7680,7 +7682,8 @@ static int _nfs4_proc_exchange_id(struct
 	if (status  != 0)
 		goto out;
 
-	status = nfs4_check_cl_exchange_flags(resp->flags);
+	status = nfs4_check_cl_exchange_flags(resp->flags,
+			clp->cl_mvops->minor_version);
 	if (status  != 0)
 		goto out;
 
--- a/include/uapi/linux/nfs4.h
+++ b/include/uapi/linux/nfs4.h
@@ -136,6 +136,8 @@
 
 #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
@@ -143,6 +145,7 @@
  */
 #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