[PATCH] NFS: Revert NFSROOT default mount options

[PATCH] NFS: Revert NFSROOT default mount options

[Chuck Lever]

Marek Belisko <marek.belisko@gmail.com> reports that recent attempts
to fix regressions in NFSROOT have broken his configuration:

> After update from 2.6.38-rc8 to 2.6.38 is mounting rootfs over nfs not possible.
> Log:
> VFS: Mounted root (nfs filesystem) on device 0:14.
> Freeing init memory: 132K
> nfs: server 10.146.1.21 not responding, still trying
> nfs: server 10.146.1.21 not responding, still trying
>
> This is never ending. I make short bisect (not too much commits
> between versions)
> and bad commit was reported: 53d4737580535e073963b91ce87d4216e434fab5
>
> NFS: NFSROOT should default to "proto=udp"
>
> I've tested on mini2440 board (DM9000, static IP).
> Is there some missing option or something else to be checked?

An examination of a network trace captured during the failure shows
that the mount is actually succeeding, but that the client is not
seeing READ replies larger than 16KB.

Last fall we removed the ad hoc mount option parser in fs/nfs/nfsroot.c
in favor of using the main parser in fs/nfs/super.c (see commit
56463e50 "NFS: Use super.c for NFSROOT mount option parsing").  That
commit changed the default NFSROOT mount options to be the same as
those employed by user space mounts.  As it turns out, that change is
not tolerated by many embedded systems.

Subsequently, commit 53d47375 introduced a clean way to specify
default mount options for NFSROOT, so we can restore the traditional
defaults for NFSROOT easily now:

   vers=2,udp,rsize=4096,wsize=4096

This should revert the changed default NFSROOT mount options
introduced with commit 56463e50.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

Hi-

Please test this, as I no longer have an NFSROOT rig here.

Can some responsible maintainer type see that this gets into
linux-next quickly for broader testing?

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

diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
index c541093..c4744e1 100644
--- a/fs/nfs/nfsroot.c
+++ b/fs/nfs/nfsroot.c
@@ -87,7 +87,7 @@
 #define NFS_ROOT		"/tftpboot/%s"
 
 /* Default NFSROOT mount options. */
-#define NFS_DEF_OPTIONS		"udp"
+#define NFS_DEF_OPTIONS		"vers=2,udp,rsize=4096,wsize=4096"
 
 /* Parameters passed from the kernel command line */
 static char nfs_root_parms[256] __initdata = "";

Re: [PATCH] NFS: Revert NFSROOT default mount options

[Belisko Marek]

On Fri, Mar 25, 2011 at 3:23 PM, Chuck Lever <chuck.lever@oracle.com> wrote:
> Marek Belisko <marek.belisko@gmail.com> reports that recent attempts
> to fix regressions in NFSROOT have broken his configuration:
>
>> After update from 2.6.38-rc8 to 2.6.38 is mounting rootfs over nfs not possible.
>> Log:
>> VFS: Mounted root (nfs filesystem) on device 0:14.
>> Freeing init memory: 132K
>> nfs: server 10.146.1.21 not responding, still trying
>> nfs: server 10.146.1.21 not responding, still trying
>>
>> This is never ending. I make short bisect (not too much commits
>> between versions)
>> and bad commit was reported: 53d4737580535e073963b91ce87d4216e434fab5
>>
>> NFS: NFSROOT should default to "proto=udp"
>>
>> I've tested on mini2440 board (DM9000, static IP).
>> Is there some missing option or something else to be checked?
>
> An examination of a network trace captured during the failure shows
> that the mount is actually succeeding, but that the client is not
> seeing READ replies larger than 16KB.
>
> Last fall we removed the ad hoc mount option parser in fs/nfs/nfsroot.c
> in favor of using the main parser in fs/nfs/super.c (see commit
> 56463e50 "NFS: Use super.c for NFSROOT mount option parsing").  That
> commit changed the default NFSROOT mount options to be the same as
> those employed by user space mounts.  As it turns out, that change is
> not tolerated by many embedded systems.
>
> Subsequently, commit 53d47375 introduced a clean way to specify
> default mount options for NFSROOT, so we can restore the traditional
> defaults for NFSROOT easily now:
>
>   vers=2,udp,rsize=4096,wsize=4096
>
> This should revert the changed default NFSROOT mount options
> introduced with commit 56463e50.
Work fine with below patch.
You can add my Tested by: Marek Belisko <marek.belisko@open-nandra.com>
>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>
> Hi-
>
> Please test this, as I no longer have an NFSROOT rig here.
>
> Can some responsible maintainer type see that this gets into
> linux-next quickly for broader testing?
>
>  fs/nfs/nfsroot.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
> index c541093..c4744e1 100644
> --- a/fs/nfs/nfsroot.c
> +++ b/fs/nfs/nfsroot.c
> @@ -87,7 +87,7 @@
>  #define NFS_ROOT               "/tftpboot/%s"
>
>  /* Default NFSROOT mount options. */
> -#define NFS_DEF_OPTIONS                "udp"
> +#define NFS_DEF_OPTIONS                "vers=2,udp,rsize=4096,wsize=4096"
>
>  /* Parameters passed from the kernel command line */
>  static char nfs_root_parms[256] __initdata = "";
>
>

regards,

marek

-- 
as simple and primitive as possible
-------------------------------------------------
Marek Belisko - OPEN-NANDRA
Freelance Developer

Ruska Nova Ves 219 | Presov, 08005 Slovak Republic
Tel: +421 915 052 184
skype: marekwhite
icq: 290551086
web: http://open-nandra.com

Re: [PATCH] NFS: Revert NFSROOT default mount options

[Chuck Lever]

On Mar 28, 2011, at 1:09 AM, Belisko Marek wrote:

> On Fri, Mar 25, 2011 at 3:23 PM, Chuck Lever <chuck.lever@oracle.com> wrote:
>> Marek Belisko <marek.belisko@gmail.com> reports that recent attempts
>> to fix regressions in NFSROOT have broken his configuration:
>> 
>>> After update from 2.6.38-rc8 to 2.6.38 is mounting rootfs over nfs not possible.
>>> Log:
>>> VFS: Mounted root (nfs filesystem) on device 0:14.
>>> Freeing init memory: 132K
>>> nfs: server 10.146.1.21 not responding, still trying
>>> nfs: server 10.146.1.21 not responding, still trying
>>> 
>>> This is never ending. I make short bisect (not too much commits
>>> between versions)
>>> and bad commit was reported: 53d4737580535e073963b91ce87d4216e434fab5
>>> 
>>> NFS: NFSROOT should default to "proto=udp"
>>> 
>>> I've tested on mini2440 board (DM9000, static IP).
>>> Is there some missing option or something else to be checked?
>> 
>> An examination of a network trace captured during the failure shows
>> that the mount is actually succeeding, but that the client is not
>> seeing READ replies larger than 16KB.
>> 
>> Last fall we removed the ad hoc mount option parser in fs/nfs/nfsroot.c
>> in favor of using the main parser in fs/nfs/super.c (see commit
>> 56463e50 "NFS: Use super.c for NFSROOT mount option parsing").  That
>> commit changed the default NFSROOT mount options to be the same as
>> those employed by user space mounts.  As it turns out, that change is
>> not tolerated by many embedded systems.
>> 
>> Subsequently, commit 53d47375 introduced a clean way to specify
>> default mount options for NFSROOT, so we can restore the traditional
>> defaults for NFSROOT easily now:
>> 
>>   vers=2,udp,rsize=4096,wsize=4096
>> 
>> This should revert the changed default NFSROOT mount options
>> introduced with commit 56463e50.
> Work fine with below patch.
> You can add my Tested by: Marek Belisko <marek.belisko@open-nandra.com>

Will do, thanks for your testing.

>> 
>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
>> ---
>> 
>> Hi-
>> 
>> Please test this, as I no longer have an NFSROOT rig here.
>> 
>> Can some responsible maintainer type see that this gets into
>> linux-next quickly for broader testing?
>> 
>>  fs/nfs/nfsroot.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>> 
>> diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
>> index c541093..c4744e1 100644
>> --- a/fs/nfs/nfsroot.c
>> +++ b/fs/nfs/nfsroot.c
>> @@ -87,7 +87,7 @@
>>  #define NFS_ROOT               "/tftpboot/%s"
>> 
>>  /* Default NFSROOT mount options. */
>> -#define NFS_DEF_OPTIONS                "udp"
>> +#define NFS_DEF_OPTIONS                "vers=2,udp,rsize=4096,wsize=4096"
>> 
>>  /* Parameters passed from the kernel command line */
>>  static char nfs_root_parms[256] __initdata = "";
>> 
>> 
> 
> regards,
> 
> marek
> 
> -- 
> as simple and primitive as possible
> -------------------------------------------------
> Marek Belisko - OPEN-NANDRA
> Freelance Developer
> 
> Ruska Nova Ves 219 | Presov, 08005 Slovak Republic
> Tel: +421 915 052 184
> skype: marekwhite
> icq: 290551086
> web: http://open-nandra.com

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

[PATCH] NFS: Revert NFSROOT default mount options

[Chuck Lever]

Marek Belisko <marek.belisko@gmail.com> reports that recent attempts
to fix regressions in NFSROOT have broken his configuration:

> After update from 2.6.38-rc8 to 2.6.38 is mounting rootfs over nfs not possible.
> Log:
> VFS: Mounted root (nfs filesystem) on device 0:14.
> Freeing init memory: 132K
> nfs: server 10.146.1.21 not responding, still trying
> nfs: server 10.146.1.21 not responding, still trying
>
> This is never ending. I make short bisect (not too much commits
> between versions)
> and bad commit was reported: 53d4737580535e073963b91ce87d4216e434fab5
>
> NFS: NFSROOT should default to "proto=udp"
>
> I've tested on mini2440 board (DM9000, static IP).
> Is there some missing option or something else to be checked?

An examination of a network trace captured during the failure shows
that the mount is actually succeeding, but that the client is not
seeing READ replies larger than 16KB.  This could be a local packet
filtering issue on the client, but we didn't troubleshoot this
further because of the reported "git bisect" result.

Last fall we removed the ad hoc mount option parser in
fs/nfs/nfsroot.c in favor of using the main parser in fs/nfs/super.c
(see commit 56463e50 "NFS: Use super.c for NFSROOT mount option
parsing").  That commit changed the default NFSROOT mount options to
be the same as those employed by user space mounts.

As it turns out, these new default mount options are not tolerated by
many embedded systems.  So far these problems have been due to
specific behavior of certain embedded NICs.  The NFS community does
not have such hardware on hand for running tests.

Commit 53d47375 recently introduced a clean way to specify default
mount options for NFSROOT, so we can now easily restore the
traditional defaults for NFSROOT:

   vers=2,udp,rsize=4096,wsize=4096

This should revert the new default NFSROOT mount options introduced
with commit 56463e50.

Tested-by: Marek Belisto <marek.belisto@open-nandra.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

Bruce or Trond-

Can one of you see that this gets into linux-next quickly?  We need
extended soak time on this one before it goes into mainline.

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

diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
index c541093..c4744e1 100644
--- a/fs/nfs/nfsroot.c
+++ b/fs/nfs/nfsroot.c
@@ -87,7 +87,7 @@
 #define NFS_ROOT		"/tftpboot/%s"
 
 /* Default NFSROOT mount options. */
-#define NFS_DEF_OPTIONS		"udp"
+#define NFS_DEF_OPTIONS		"vers=2,udp,rsize=4096,wsize=4096"
 
 /* Parameters passed from the kernel command line */
 static char nfs_root_parms[256] __initdata = "";