2019-08-28 10:23:58

by Murphy Zhou

[permalink] [raw]
Subject: nfs-for-5.3-3 update "breaks" NFSv4 directIO somehow

Hi,

If write to file with O_DIRECT, then read it without O_DIRECT, read returns 0.
From tshark output, looks like the READ call is missing.

LTP[1] dio tests spot this. Things work well before this update.

Bisect log is pointing to:

commit 7e10cc25bfa0dd3602bbcf5cc9c759a90eb675dc
Author: Trond Myklebust <[email protected]>
Date: Fri Aug 9 12:06:43 2019 -0400

NFS: Don't refresh attributes with mounted-on-file informatio

With this commit reverted, the tests pass again.

It's only about NFSv4(4.0 4.1 and 4.2), NFSv3 works well.

Bisect log, outputs of tshark, sample test programme derived from
LTP diotest02.c and a simple test script are attached.

If this is an expected change, we will need to update the testcases.

Thanks,
Murphy

[1] https://github.com/linux-test-project/ltp.git


Attachments:
(No filename) (848.00 B)
dio02.c (3.70 kB)
test.sh (388.00 B)
fail.tshark (2.26 kB)
pass.tshark (2.69 kB)
Download all attachments

2019-08-28 15:33:08

by Trond Myklebust

[permalink] [raw]
Subject: Re: nfs-for-5.3-3 update "breaks" NFSv4 directIO somehow

On Wed, 2019-08-28 at 18:22 +0800, Murphy Zhou wrote:
> Hi,
>
> If write to file with O_DIRECT, then read it without O_DIRECT, read
> returns 0.
> From tshark output, looks like the READ call is missing.
>
> LTP[1] dio tests spot this. Things work well before this update.
>
> Bisect log is pointing to:
>
> commit 7e10cc25bfa0dd3602bbcf5cc9c759a90eb675dc
> Author: Trond Myklebust <[email protected]>
> Date: Fri Aug 9 12:06:43 2019 -0400
>
> NFS: Don't refresh attributes with mounted-on-file
> informatio
>
> With this commit reverted, the tests pass again.
>
> It's only about NFSv4(4.0 4.1 and 4.2), NFSv3 works well.
>
> Bisect log, outputs of tshark, sample test programme derived from
> LTP diotest02.c and a simple test script are attached.
>
> If this is an expected change, we will need to update the testcases.

That is not intentional, so thanks for reporting it! Does the following
fix help?

8<------------------------
From ce61618bc085d8cea8a614b5e1eb09e16ea8e036 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <[email protected]>
Date: Wed, 28 Aug 2019 11:26:13 -0400
Subject: [PATCH] NFS: Fix inode fileid checks in attribute revalidation code

We want to throw out the attrbute if it refers to the mounted on fileid,
and not the real fileid. However we do not want to block cache consistency
updates from NFSv4 writes.

Reported-by: Murphy Zhou <[email protected]>
Fixes: 7e10cc25bfa0 ("NFS: Don't refresh attributes with mounted-on-file...")
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/inode.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index c764cfe456e5..d7e78b220cf6 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1404,10 +1404,11 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat
return 0;

/* No fileid? Just exit */
- if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
- return 0;
+ if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
+ if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
+ return 0;
/* Has the inode gone and changed behind our back? */
- if (nfsi->fileid != fattr->fileid) {
+ } else if (nfsi->fileid != fattr->fileid) {
/* Is this perhaps the mounted-on fileid? */
if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
nfsi->fileid == fattr->mounted_on_fileid)
@@ -1808,10 +1809,11 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
atomic_read(&inode->i_count), fattr->valid);

/* No fileid? Just exit */
- if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
- return 0;
+ if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
+ if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
+ return 0;
/* Has the inode gone and changed behind our back? */
- if (nfsi->fileid != fattr->fileid) {
+ } else if (nfsi->fileid != fattr->fileid) {
/* Is this perhaps the mounted-on fileid? */
if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
nfsi->fileid == fattr->mounted_on_fileid)
--
2.21.0

--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
[email protected]


2019-08-29 00:08:02

by Murphy Zhou

[permalink] [raw]
Subject: Re: nfs-for-5.3-3 update "breaks" NFSv4 directIO somehow

On Wed, Aug 28, 2019 at 03:32:25PM +0000, Trond Myklebust wrote:
> On Wed, 2019-08-28 at 18:22 +0800, Murphy Zhou wrote:
> > Hi,
> >
> > If write to file with O_DIRECT, then read it without O_DIRECT, read
> > returns 0.
> > From tshark output, looks like the READ call is missing.
> >
> > LTP[1] dio tests spot this. Things work well before this update.
> >
> > Bisect log is pointing to:
> >
> > commit 7e10cc25bfa0dd3602bbcf5cc9c759a90eb675dc
> > Author: Trond Myklebust <[email protected]>
> > Date: Fri Aug 9 12:06:43 2019 -0400
> >
> > NFS: Don't refresh attributes with mounted-on-file
> > informatio
> >
> > With this commit reverted, the tests pass again.
> >
> > It's only about NFSv4(4.0 4.1 and 4.2), NFSv3 works well.
> >
> > Bisect log, outputs of tshark, sample test programme derived from
> > LTP diotest02.c and a simple test script are attached.
> >
> > If this is an expected change, we will need to update the testcases.
>
> That is not intentional, so thanks for reporting it! Does the following
> fix help?

This patch fixed the issue. Thanks!

Murphy

>
> 8<------------------------
> From ce61618bc085d8cea8a614b5e1eb09e16ea8e036 Mon Sep 17 00:00:00 2001
> From: Trond Myklebust <[email protected]>
> Date: Wed, 28 Aug 2019 11:26:13 -0400
> Subject: [PATCH] NFS: Fix inode fileid checks in attribute revalidation code
>
> We want to throw out the attrbute if it refers to the mounted on fileid,
> and not the real fileid. However we do not want to block cache consistency
> updates from NFSv4 writes.
>
> Reported-by: Murphy Zhou <[email protected]>
> Fixes: 7e10cc25bfa0 ("NFS: Don't refresh attributes with mounted-on-file...")
> Signed-off-by: Trond Myklebust <[email protected]>
> ---
> fs/nfs/inode.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index c764cfe456e5..d7e78b220cf6 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -1404,10 +1404,11 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat
> return 0;
>
> /* No fileid? Just exit */
> - if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
> - return 0;
> + if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
> + if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> + return 0;
> /* Has the inode gone and changed behind our back? */
> - if (nfsi->fileid != fattr->fileid) {
> + } else if (nfsi->fileid != fattr->fileid) {
> /* Is this perhaps the mounted-on fileid? */
> if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
> nfsi->fileid == fattr->mounted_on_fileid)
> @@ -1808,10 +1809,11 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
> atomic_read(&inode->i_count), fattr->valid);
>
> /* No fileid? Just exit */
> - if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
> - return 0;
> + if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
> + if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> + return 0;
> /* Has the inode gone and changed behind our back? */
> - if (nfsi->fileid != fattr->fileid) {
> + } else if (nfsi->fileid != fattr->fileid) {
> /* Is this perhaps the mounted-on fileid? */
> if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
> nfsi->fileid == fattr->mounted_on_fileid)
> --
> 2.21.0
>
> --
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> [email protected]
>
>

2019-09-09 14:15:05

by Murphy Zhou

[permalink] [raw]
Subject: Re: nfs-for-5.3-3 update "breaks" NFSv4 directIO somehow

On Wed, Aug 28, 2019 at 03:32:25PM +0000, Trond Myklebust wrote:
> On Wed, 2019-08-28 at 18:22 +0800, Murphy Zhou wrote:
> > Hi,
> >
> > If write to file with O_DIRECT, then read it without O_DIRECT, read
> > returns 0.
> > From tshark output, looks like the READ call is missing.
> >
> > LTP[1] dio tests spot this. Things work well before this update.
> >
> > Bisect log is pointing to:
> >
> > commit 7e10cc25bfa0dd3602bbcf5cc9c759a90eb675dc
> > Author: Trond Myklebust <[email protected]>
> > Date: Fri Aug 9 12:06:43 2019 -0400
> >
> > NFS: Don't refresh attributes with mounted-on-file
> > informatio
> >
> > With this commit reverted, the tests pass again.
> >
> > It's only about NFSv4(4.0 4.1 and 4.2), NFSv3 works well.
> >
> > Bisect log, outputs of tshark, sample test programme derived from
> > LTP diotest02.c and a simple test script are attached.
> >
> > If this is an expected change, we will need to update the testcases.
>
> That is not intentional, so thanks for reporting it! Does the following
> fix help?

Hi Trond,

Will you queue this fix for v5.3 ?

Thanks!

>
> 8<------------------------
> From ce61618bc085d8cea8a614b5e1eb09e16ea8e036 Mon Sep 17 00:00:00 2001
> From: Trond Myklebust <[email protected]>
> Date: Wed, 28 Aug 2019 11:26:13 -0400
> Subject: [PATCH] NFS: Fix inode fileid checks in attribute revalidation code
>
> We want to throw out the attrbute if it refers to the mounted on fileid,
> and not the real fileid. However we do not want to block cache consistency
> updates from NFSv4 writes.
>
> Reported-by: Murphy Zhou <[email protected]>
> Fixes: 7e10cc25bfa0 ("NFS: Don't refresh attributes with mounted-on-file...")
> Signed-off-by: Trond Myklebust <[email protected]>
> ---
> fs/nfs/inode.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index c764cfe456e5..d7e78b220cf6 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -1404,10 +1404,11 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat
> return 0;
>
> /* No fileid? Just exit */
> - if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
> - return 0;
> + if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
> + if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> + return 0;
> /* Has the inode gone and changed behind our back? */
> - if (nfsi->fileid != fattr->fileid) {
> + } else if (nfsi->fileid != fattr->fileid) {
> /* Is this perhaps the mounted-on fileid? */
> if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
> nfsi->fileid == fattr->mounted_on_fileid)
> @@ -1808,10 +1809,11 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
> atomic_read(&inode->i_count), fattr->valid);
>
> /* No fileid? Just exit */
> - if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
> - return 0;
> + if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
> + if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> + return 0;
> /* Has the inode gone and changed behind our back? */
> - if (nfsi->fileid != fattr->fileid) {
> + } else if (nfsi->fileid != fattr->fileid) {
> /* Is this perhaps the mounted-on fileid? */
> if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
> nfsi->fileid == fattr->mounted_on_fileid)
> --
> 2.21.0
>
> --
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> [email protected]
>
>

2019-09-09 14:15:26

by Trond Myklebust

[permalink] [raw]
Subject: Re: nfs-for-5.3-3 update "breaks" NFSv4 directIO somehow

On Mon, 2019-09-09 at 10:36 +0800, Murphy Zhou wrote:
> On Wed, Aug 28, 2019 at 03:32:25PM +0000, Trond Myklebust wrote:
> > On Wed, 2019-08-28 at 18:22 +0800, Murphy Zhou wrote:
> > > Hi,
> > >
> > > If write to file with O_DIRECT, then read it without O_DIRECT,
> > > read
> > > returns 0.
> > > From tshark output, looks like the READ call is missing.
> > >
> > > LTP[1] dio tests spot this. Things work well before this update.
> > >
> > > Bisect log is pointing to:
> > >
> > > commit 7e10cc25bfa0dd3602bbcf5cc9c759a90eb675dc
> > > Author: Trond Myklebust <[email protected]>
> > > Date: Fri Aug 9 12:06:43 2019 -0400
> > >
> > > NFS: Don't refresh attributes with mounted-on-file
> > > informatio
> > >
> > > With this commit reverted, the tests pass again.
> > >
> > > It's only about NFSv4(4.0 4.1 and 4.2), NFSv3 works well.
> > >
> > > Bisect log, outputs of tshark, sample test programme derived from
> > > LTP diotest02.c and a simple test script are attached.
> > >
> > > If this is an expected change, we will need to update the
> > > testcases.
> >
> > That is not intentional, so thanks for reporting it! Does the
> > following
> > fix help?
>
> Hi Trond,
>
> Will you queue this fix for v5.3 ?
>
> Thanks!
>

It is already in 5.3-rc8:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eb3d8f42231aec65b64b079dd17bd6c008a3fe29

Cheers
Trond

> > 8<------------------------
> > From ce61618bc085d8cea8a614b5e1eb09e16ea8e036 Mon Sep 17 00:00:00
> > 2001
> > From: Trond Myklebust <[email protected]>
> > Date: Wed, 28 Aug 2019 11:26:13 -0400
> > Subject: [PATCH] NFS: Fix inode fileid checks in attribute
> > revalidation code
> >
> > We want to throw out the attrbute if it refers to the mounted on
> > fileid,
> > and not the real fileid. However we do not want to block cache
> > consistency
> > updates from NFSv4 writes.
> >
> > Reported-by: Murphy Zhou <[email protected]>
> > Fixes: 7e10cc25bfa0 ("NFS: Don't refresh attributes with mounted-
> > on-file...")
> > Signed-off-by: Trond Myklebust <[email protected]>
> > ---
> > fs/nfs/inode.c | 14 ++++++++------
> > 1 file changed, 8 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> > index c764cfe456e5..d7e78b220cf6 100644
> > --- a/fs/nfs/inode.c
> > +++ b/fs/nfs/inode.c
> > @@ -1404,10 +1404,11 @@ static int
> > nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr
> > *fat
> > return 0;
> >
> > /* No fileid? Just exit */
> > - if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
> > - return 0;
> > + if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
> > + if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> > + return 0;
> > /* Has the inode gone and changed behind our back? */
> > - if (nfsi->fileid != fattr->fileid) {
> > + } else if (nfsi->fileid != fattr->fileid) {
> > /* Is this perhaps the mounted-on fileid? */
> > if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> > &&
> > nfsi->fileid == fattr->mounted_on_fileid)
> > @@ -1808,10 +1809,11 @@ static int nfs_update_inode(struct inode
> > *inode, struct nfs_fattr *fattr)
> > atomic_read(&inode->i_count), fattr->valid);
> >
> > /* No fileid? Just exit */
> > - if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
> > - return 0;
> > + if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
> > + if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> > + return 0;
> > /* Has the inode gone and changed behind our back? */
> > - if (nfsi->fileid != fattr->fileid) {
> > + } else if (nfsi->fileid != fattr->fileid) {
> > /* Is this perhaps the mounted-on fileid? */
> > if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> > &&
> > nfsi->fileid == fattr->mounted_on_fileid)
> > --
> > 2.21.0
> >
> > --
> > Trond Myklebust
> > Linux NFS client maintainer, Hammerspace
> > [email protected]
> >
> >
Trond Myklebust
CTO, Hammerspace Inc
4300 El Camino Real, Suite 105
Los Altos, CA 94022
http://www.hammer.space

--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
[email protected]


2019-09-09 14:17:04

by Murphy Zhou

[permalink] [raw]
Subject: Re: nfs-for-5.3-3 update "breaks" NFSv4 directIO somehow

On Mon, Sep 09, 2019 at 02:58:35AM +0000, Trond Myklebust wrote:
> On Mon, 2019-09-09 at 10:36 +0800, Murphy Zhou wrote:
> > On Wed, Aug 28, 2019 at 03:32:25PM +0000, Trond Myklebust wrote:
> > > On Wed, 2019-08-28 at 18:22 +0800, Murphy Zhou wrote:
> > > > Hi,
> > > >
> > > > If write to file with O_DIRECT, then read it without O_DIRECT,
> > > > read
> > > > returns 0.
> > > > From tshark output, looks like the READ call is missing.
> > > >
> > > > LTP[1] dio tests spot this. Things work well before this update.
> > > >
> > > > Bisect log is pointing to:
> > > >
> > > > commit 7e10cc25bfa0dd3602bbcf5cc9c759a90eb675dc
> > > > Author: Trond Myklebust <[email protected]>
> > > > Date: Fri Aug 9 12:06:43 2019 -0400
> > > >
> > > > NFS: Don't refresh attributes with mounted-on-file
> > > > informatio
> > > >
> > > > With this commit reverted, the tests pass again.
> > > >
> > > > It's only about NFSv4(4.0 4.1 and 4.2), NFSv3 works well.
> > > >
> > > > Bisect log, outputs of tshark, sample test programme derived from
> > > > LTP diotest02.c and a simple test script are attached.
> > > >
> > > > If this is an expected change, we will need to update the
> > > > testcases.
> > >
> > > That is not intentional, so thanks for reporting it! Does the
> > > following
> > > fix help?
> >
> > Hi Trond,
> >
> > Will you queue this fix for v5.3 ?
> >
> > Thanks!
> >
>
> It is already in 5.3-rc8:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eb3d8f42231aec65b64b079dd17bd6c008a3fe29


Oh sorry.. I'll go to get some coffee. Checked that with this patch regression
tests looks good.

Thanks!
M

>
> Cheers
> Trond
>
> > > 8<------------------------
> > > From ce61618bc085d8cea8a614b5e1eb09e16ea8e036 Mon Sep 17 00:00:00
> > > 2001
> > > From: Trond Myklebust <[email protected]>
> > > Date: Wed, 28 Aug 2019 11:26:13 -0400
> > > Subject: [PATCH] NFS: Fix inode fileid checks in attribute
> > > revalidation code
> > >
> > > We want to throw out the attrbute if it refers to the mounted on
> > > fileid,
> > > and not the real fileid. However we do not want to block cache
> > > consistency
> > > updates from NFSv4 writes.
> > >
> > > Reported-by: Murphy Zhou <[email protected]>
> > > Fixes: 7e10cc25bfa0 ("NFS: Don't refresh attributes with mounted-
> > > on-file...")
> > > Signed-off-by: Trond Myklebust <[email protected]>
> > > ---
> > > fs/nfs/inode.c | 14 ++++++++------
> > > 1 file changed, 8 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> > > index c764cfe456e5..d7e78b220cf6 100644
> > > --- a/fs/nfs/inode.c
> > > +++ b/fs/nfs/inode.c
> > > @@ -1404,10 +1404,11 @@ static int
> > > nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr
> > > *fat
> > > return 0;
> > >
> > > /* No fileid? Just exit */
> > > - if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
> > > - return 0;
> > > + if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
> > > + if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> > > + return 0;
> > > /* Has the inode gone and changed behind our back? */
> > > - if (nfsi->fileid != fattr->fileid) {
> > > + } else if (nfsi->fileid != fattr->fileid) {
> > > /* Is this perhaps the mounted-on fileid? */
> > > if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> > > &&
> > > nfsi->fileid == fattr->mounted_on_fileid)
> > > @@ -1808,10 +1809,11 @@ static int nfs_update_inode(struct inode
> > > *inode, struct nfs_fattr *fattr)
> > > atomic_read(&inode->i_count), fattr->valid);
> > >
> > > /* No fileid? Just exit */
> > > - if (!(fattr->valid & NFS_ATTR_FATTR_FILEID))
> > > - return 0;
> > > + if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
> > > + if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> > > + return 0;
> > > /* Has the inode gone and changed behind our back? */
> > > - if (nfsi->fileid != fattr->fileid) {
> > > + } else if (nfsi->fileid != fattr->fileid) {
> > > /* Is this perhaps the mounted-on fileid? */
> > > if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
> > > &&
> > > nfsi->fileid == fattr->mounted_on_fileid)
> > > --
> > > 2.21.0
> > >
> > > --
> > > Trond Myklebust
> > > Linux NFS client maintainer, Hammerspace
> > > [email protected]
> > >
> > >
> Trond Myklebust
> CTO, Hammerspace Inc
> 4300 El Camino Real, Suite 105
> Los Altos, CA 94022
> http://www.hammer.space
>
> --
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> [email protected]
>
>