[PATCH 1/1] NFSv4.2: support EXCHGID4_FLAG_SUPP_FENCE_OPS 4.2 EXCHANGE_ID flag

[PATCH 1/1] NFSv4.2: support EXCHGID4_FLAG_SUPP_FENCE_OPS 4.2 EXCHANGE_ID flag

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

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.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
CC: <stable@vger.kernel.org>
---
 fs/nfs/nfs4proc.c         | 9 ++++++---
 include/uapi/linux/nfs4.h | 1 +
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 6e95c85fe395..20f2e0f5c5ba 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -8039,9 +8039,11 @@ int nfs4_proc_secinfo(struct inode *dir, const struct qstr *name,
  * 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, int 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))
@@ -8454,7 +8456,8 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, const struct cred *cre
 	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;
 
diff --git a/include/uapi/linux/nfs4.h b/include/uapi/linux/nfs4.h
index bf197e99b98f..3faa94867fec 100644
--- a/include/uapi/linux/nfs4.h
+++ b/include/uapi/linux/nfs4.h
@@ -146,6 +146,7 @@
  */
 #define EXCHGID4_FLAG_MASK_A			0x40070103
 #define EXCHGID4_FLAG_MASK_R			0x80070103
+#define EXCHGID4_2_FLAG_MASK_R			0x80070104
 
 #define SEQ4_STATUS_CB_PATH_DOWN		0x00000001
 #define SEQ4_STATUS_CB_GSS_CONTEXTS_EXPIRING	0x00000002
-- 
2.18.2

Re: [PATCH 1/1] NFSv4.2: support EXCHGID4_FLAG_SUPP_FENCE_OPS 4.2 EXCHANGE_ID flag

[Trond Myklebust]

Hi Olga,

On Thu, 2020-10-15 at 09:35 -0400, Olga Kornievskaia wrote:
> From: Olga Kornievskaia <kolga@netapp.com>
> 
> 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.
> 
> Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> CC: <stable@vger.kernel.org>
> ---
>  fs/nfs/nfs4proc.c         | 9 ++++++---
>  include/uapi/linux/nfs4.h | 1 +
>  2 files changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 6e95c85fe395..20f2e0f5c5ba 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -8039,9 +8039,11 @@ int nfs4_proc_secinfo(struct inode *dir, const
> struct qstr *name,
>   * 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, int 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))
> @@ -8454,7 +8456,8 @@ static int _nfs4_proc_exchange_id(struct
> nfs_client *clp, const struct cred *cre
>  	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;
>  
> diff --git a/include/uapi/linux/nfs4.h b/include/uapi/linux/nfs4.h
> index bf197e99b98f..3faa94867fec 100644
> --- a/include/uapi/linux/nfs4.h
> +++ b/include/uapi/linux/nfs4.h
> @@ -146,6 +146,7 @@
>   */
>  #define EXCHGID4_FLAG_MASK_A			0x40070103
>  #define EXCHGID4_FLAG_MASK_R			0x80070103
> +#define EXCHGID4_2_FLAG_MASK_R			0x80070104
>  
>  #define SEQ4_STATUS_CB_PATH_DOWN		0x00000001
>  #define SEQ4_STATUS_CB_GSS_CONTEXTS_EXPIRING	0x00000002

Thanks! I find it very annoying that the NFSv4.2 spec allows the server
to return a new EXCHANGE_ID flag that is not backward compatible with
NFSv4.1, despite the client not changing its arguments and asking for
that behaviour.

Can you please add in a definition for EXCHGID4_FLAG_SUPP_FENCE_OPS
while we're at it, so that we can document why there is a change in the
mask?

Also please note that EXCHGID4_2_FLAG_MASK_R needs to take a value of
(EXCHGID4_FLAG_MASK_R | EXCHGID4_FLAG_SUPP_FENCE_OPS), since all the
existing flags in EXCHGID4_FLAG_MASK_R are still valid. So the above
define needs to read as

#define EXCHGID4_2_FLAG_MASK_R		0x80070107


-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com

[PATCH 1/1] NFSv4.2: support EXCHGID4_FLAG_SUPP_FENCE_OPS 4.2 EXCHANGE_ID flag

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

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.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
CC: <stable@vger.kernel.org>
---
 fs/nfs/nfs4proc.c         | 9 ++++++---
 include/uapi/linux/nfs4.h | 3 +++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 6e95c85fe395..20f2e0f5c5ba 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -8039,9 +8039,11 @@ int nfs4_proc_secinfo(struct inode *dir, const struct qstr *name,
  * 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, int 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))
@@ -8454,7 +8456,8 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, const struct cred *cre
 	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;
 
diff --git a/include/uapi/linux/nfs4.h b/include/uapi/linux/nfs4.h
index bf197e99b98f..ed5415e0f1c1 100644
--- a/include/uapi/linux/nfs4.h
+++ b/include/uapi/linux/nfs4.h
@@ -139,6 +139,8 @@
 
 #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
@@ -146,6 +148,7 @@
  */
 #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
-- 
2.18.2