[PATCH] NFS: suppressing showing of default mount port value in /proc fixed

[PATCH] NFS: suppressing showing of default mount port value in /proc fixed

[Stanislav Kinsbursky]

Default value for mount server port is set to NFS_UNSPEC_PORT (-1) and will not
be changed during parsing mount options for mound data version 6. This default
value will be showed for mountport in /proc/mounts always since current default
check is for zero value. This small mistake leads to big problem, because
during umount.nfs execution from old user-space utils (at least nfs-utils
1.0.9) this value will be used as the server port to connect to. This request
will be rejected (since port is 65535) and thus nfs mount point can't be
unmounted.

Kernel version affected: 2.6.37-rc4

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>

---
 fs/nfs/super.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 6d6e21d..fd4cac8 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -681,7 +681,8 @@ static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 
 	if (nfss->mountd_version || showdefaults)
 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
-	if (nfss->mountd_port || showdefaults)
+	if (nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT ||
+			showdefaults)
 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
 
 	nfs_show_mountd_netid(m, nfss, showdefaults);

Re: [PATCH] NFS: suppressing showing of default mount port value in /proc fixed

[Chuck Lever]

On Dec 3, 2010, at 12:11 PM, Stanislav Kinsbursky wrote:

> Default value for mount server port is set to NFS_UNSPEC_PORT (-1) and will not
> be changed during parsing mount options for mound data version 6. This default
> value will be showed for mountport in /proc/mounts always since current default
> check is for zero value. This small mistake leads to big problem, because
> during umount.nfs execution from old user-space utils (at least nfs-utils
> 1.0.9) this value will be used as the server port to connect to. This request
> will be rejected (since port is 65535) and thus nfs mount point can't be
> unmounted.

Note: this is only possible if /etc/mtab is a link to /proc/mounts.  Not all systems have this configuration.

> 
> Kernel version affected: 2.6.37-rc4
> 
> Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
> 
> ---
> fs/nfs/super.c |    3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index 6d6e21d..fd4cac8 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -681,7 +681,8 @@ static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
> 
> 	if (nfss->mountd_version || showdefaults)
> 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
> -	if (nfss->mountd_port || showdefaults)
> +	if (nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT ||
> +			showdefaults)
> 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
> 
> 	nfs_show_mountd_netid(m, nfss, showdefaults);
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
Chuck Lever
chuck[dot]lever[at]oracle[dot]com

Re: [PATCH] NFS: suppressing showing of default mount port value in /proc fixed

[Kinsbursky Stanislav]

03.12.2010 20:35, Chuck Lever пишет:
>
> On Dec 3, 2010, at 12:11 PM, Stanislav Kinsbursky wrote:
>
>> Default value for mount server port is set to NFS_UNSPEC_PORT (-1) and will not
>> be changed during parsing mount options for mound data version 6. This default
>> value will be showed for mountport in /proc/mounts always since current default
>> check is for zero value. This small mistake leads to big problem, because
>> during umount.nfs execution from old user-space utils (at least nfs-utils
>> 1.0.9) this value will be used as the server port to connect to. This request
>> will be rejected (since port is 65535) and thus nfs mount point can't be
>> unmounted.
>
> Note: this is only possible if /etc/mtab is a link to /proc/mounts.  Not all systems have this configuration.
>

I found it on CentOs 5.5 with RHEL6 kernel.
Actually, the current patch has a specific flaw: if mount port is not passed by nfs utils using mount options version 6, then it will be set to 0 and showed in /proc/mounts as "mountport=0".
Another fix solution is to call "nfs_set_port(sap, &args->nfs_server.port, 0);" when parsing mount options version 6 (like in done in default casein nfs_validate_mount_data) instead of changing 
nfs_show_mountd_options().


>>
>> Kernel version affected: 2.6.37-rc4
>>
>> Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
>>
>> ---
>> fs/nfs/super.c |    3 ++-
>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
>> index 6d6e21d..fd4cac8 100644
>> --- a/fs/nfs/super.c
>> +++ b/fs/nfs/super.c
>> @@ -681,7 +681,8 @@ static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
>>
>> 	if (nfss->mountd_version || showdefaults)
>> 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
>> -	if (nfss->mountd_port || showdefaults)
>> +	if (nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT ||
>> +			showdefaults)
>> 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
>>
>> 	nfs_show_mountd_netid(m, nfss, showdefaults);
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>


-- 
Best regards,
Stanislav Kinsbursky

Re: [PATCH] NFS: suppressing showing of default mount port value in /proc fixed

[Chuck Lever]

On Dec 3, 2010, at 1:01 PM, Kinsbursky Stanislav wrote:

> 03.12.2010 20:35, Chuck Lever пишет:
>> 
>> On Dec 3, 2010, at 12:11 PM, Stanislav Kinsbursky wrote:
>> 
>>> Default value for mount server port is set to NFS_UNSPEC_PORT (-1) and will not
>>> be changed during parsing mount options for mound data version 6. This default
>>> value will be showed for mountport in /proc/mounts always since current default
>>> check is for zero value. This small mistake leads to big problem, because
>>> during umount.nfs execution from old user-space utils (at least nfs-utils
>>> 1.0.9) this value will be used as the server port to connect to. This request
>>> will be rejected (since port is 65535) and thus nfs mount point can't be
>>> unmounted.
>> 
>> Note: this is only possible if /etc/mtab is a link to /proc/mounts.  Not all systems have this configuration.
>> 
> 
> I found it on CentOs 5.5 with RHEL6 kernel.
> Actually, the current patch has a specific flaw: if mount port is not passed by nfs utils using mount options version 6, then it will be set to 0 and showed in /proc/mounts as "mountport=0".

Right: zero and negative one are both special internal port values that should not be displayed in /proc/mounts.  Why not check if mountport > 0 instead?

> Another fix solution is to call "nfs_set_port(sap, &args->nfs_server.port, 0);" when parsing mount options version 6 (like in done in default casein nfs_validate_mount_data) instead of changing nfs_show_mountd_options().

I'm not sure I follow here.  Why would setting nfsport be the right thing to do?  The default case is for text-based mounts only.

> Kernel version affected: 2.6.37-rc4
>>> 
>>> Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
>>> 
>>> ---
>>> fs/nfs/super.c |    3 ++-
>>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>> 
>>> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
>>> index 6d6e21d..fd4cac8 100644
>>> --- a/fs/nfs/super.c
>>> +++ b/fs/nfs/super.c
>>> @@ -681,7 +681,8 @@ static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
>>> 
>>> 	if (nfss->mountd_version || showdefaults)
>>> 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
>>> -	if (nfss->mountd_port || showdefaults)
>>> +	if (nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT ||
>>> +			showdefaults)
>>> 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
>>> 
>>> 	nfs_show_mountd_netid(m, nfss, showdefaults);
>>> 
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> 
> 
> 
> -- 
> Best regards,
> Stanislav Kinsbursky

-- 
Chuck Lever
chuck[dot]lever[at]oracle[dot]com

Re: [PATCH] NFS: suppressing showing of default mount port value in /proc fixed

[Kinsbursky Stanislav]

03.12.2010 21:17, Chuck Lever пишет:
>
> On Dec 3, 2010, at 1:01 PM, Kinsbursky Stanislav wrote:
>
>> 03.12.2010 20:35, Chuck Lever пишет:
>>>
>>> On Dec 3, 2010, at 12:11 PM, Stanislav Kinsbursky wrote:
>>>
>>>> Default value for mount server port is set to NFS_UNSPEC_PORT (-1) and will not
>>>> be changed during parsing mount options for mound data version 6. This default
>>>> value will be showed for mountport in /proc/mounts always since current default
>>>> check is for zero value. This small mistake leads to big problem, because
>>>> during umount.nfs execution from old user-space utils (at least nfs-utils
>>>> 1.0.9) this value will be used as the server port to connect to. This request
>>>> will be rejected (since port is 65535) and thus nfs mount point can't be
>>>> unmounted.
>>>
>>> Note: this is only possible if /etc/mtab is a link to /proc/mounts.  Not all systems have this configuration.
>>>
>>
>> I found it on CentOs 5.5 with RHEL6 kernel.
>> Actually, the current patch has a specific flaw: if mount port is not passed by nfs utils using mount options version 6, then it will be set to 0 and showed in /proc/mounts as "mountport=0".
>
> Right: zero and negative one are both special internal port values that should not be displayed in /proc/mounts.  Why not check if mountport>  0 instead?
>

Yep, you right. I'll sent second version.

>> Another fix solution is to call "nfs_set_port(sap,&args->nfs_server.port, 0);" when parsing mount options version 6 (like in done in default casein nfs_validate_mount_data) instead of changing nfs_show_mountd_options().
>
> I'm not sure I follow here.  Why would setting nfsport be the right thing to do?  The default case is for text-based mounts only.
>
>> Kernel version affected: 2.6.37-rc4
>>>>
>>>> Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
>>>>
>>>> ---
>>>> fs/nfs/super.c |    3 ++-
>>>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
>>>> index 6d6e21d..fd4cac8 100644
>>>> --- a/fs/nfs/super.c
>>>> +++ b/fs/nfs/super.c
>>>> @@ -681,7 +681,8 @@ static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
>>>>
>>>> 	if (nfss->mountd_version || showdefaults)
>>>> 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
>>>> -	if (nfss->mountd_port || showdefaults)
>>>> +	if (nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT ||
>>>> +			showdefaults)
>>>> 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
>>>>
>>>> 	nfs_show_mountd_netid(m, nfss, showdefaults);
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>
>>
>>
>> --
>> Best regards,
>> Stanislav Kinsbursky
>


-- 
Best regards,
Stanislav Kinsbursky