[PATCH nfs-utils 0/2] fixes for protocol fallback on mount

[PATCH nfs-utils 0/2] fixes for protocol fallback on mount

[NeilBrown]

Two unrelated patches which both relate to protocol fallback
when mounting an NFS filesystem.

---

Andreas Schwab (1):
      Fix uninitialised variable usage in nfs_options2pmap

NeilBrown (1):
      Fix protocol minor version fall-back


 utils/mount/network.c |    5 ++++-
 utils/mount/stropts.c |    3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

--
Signature

[PATCH 1/2] Fix uninitialised variable usage in nfs_options2pmap

[NeilBrown]

From: Andreas Schwab <schwab@suse.com>

Commit 5bea22e33b7a introduced a regression.  Prior to that commit
nfs_nfs_version would set *version to 0 if NFS version wasn't specified.
Since that commit, version.v_mode is set to V_DEFAULT if the NFS version
isn't specified, but nfs_options2pmap uses version.major without checking
v_mode.  This can lead to incorrect behaviour.
In particular fall-ack to v3 if server doesn't support v4 can fail.

So test v_mode before using version.major.

URL: https://bugzilla.opensuse.org/show_bug.cgi?id=956743
Fixes: 5bea22e33b7a ("mount.nfs: Add struct nfs_version and generalize version parsing")
Signed-off-by: NeilBrown <neilb@suse.com>
---
 utils/mount/network.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/utils/mount/network.c b/utils/mount/network.c
index ebc39d361e2c..8a9bf1476d51 100644
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -1631,7 +1631,10 @@ int nfs_options2pmap(struct mount_options *options,
 		return 0;
 	if (!nfs_nfs_version(options, &version))
 		return 0;
-	nfs_pmap->pm_vers = version.major;
+	if (version.v_mode == V_DEFAULT)
+		nfs_pmap->pm_vers = 0;
+	else
+		nfs_pmap->pm_vers = version.major;
 	if (!nfs_nfs_protocol(options, &nfs_pmap->pm_prot))
 		return 0;
 	if (!nfs_nfs_port(options, &nfs_pmap->pm_port))

[PATCH 2/2] Fix protocol minor version fall-back

[NeilBrown]

mount.nfs currently expects mount(2) to fail with EPROTONOSUPPORT if
the kernel doesn't understand the requested NFS version.

Unfortunately if the requested minor is not known to the kernel
it returns -EINVAL.
In kernels since 3.11 this can happen in nfs4_alloc_client(), if
compiled without NFS_V4_2.

More generally it can happen in in nfs_validate_text_mount_data()
when nfs_parse_mount_options() returns 0 because nfs_parse_version_string()
didn't recognise the version.

EPROTONOSUPPORT is only returned if NFSv4 support is completely compiled out.

So nfs_autonegotiate needs to check for EINVAL as well as EPROTONOSUPPORT.

URL: https://bugzilla.opensuse.org/show_bug.cgi?id=959211
Reported-by: Takashi Iwai <tiwai@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
---
 utils/mount/stropts.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index c8f5a6d223e7..86829a902bfd 100644
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -841,6 +841,9 @@ check_result:
 	case EPROTONOSUPPORT:
 		/* A clear indication that the server or our
 		 * client does not support NFS version 4 and minor */
+	case EINVAL:
+		/* A less clear indication that our client
+		 * does not support NFSv4 minor version. */
 		if (mi->version.v_mode == V_GENERAL &&
 			mi->version.minor == 0)
 				return result;

Re: [PATCH nfs-utils 0/2] fixes for protocol fallback on mount

[Steve Dickson]

On 12/16/2015 08:56 PM, NeilBrown wrote:
> Two unrelated patches which both relate to protocol fallback
> when mounting an NFS filesystem.
> 
> ---
> 
> Andreas Schwab (1):
>       Fix uninitialised variable usage in nfs_options2pmap
> 
> NeilBrown (1):
>       Fix protocol minor version fall-back
Both patches committed! Thank you!!

steved.

> 
> 
>  utils/mount/network.c |    5 ++++-
>  utils/mount/stropts.c |    3 +++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> --
> Signature
>