2007-06-14 15:56:31

by Kalpak Shah

[permalink] [raw]
Subject: [PATCH 4/6] add noversion mount option

This patch adds a "noversion" mount option to disable inode version
updates.

Signed-off-by: Andreas Dilger <[email protected]>
Signed-off-by: Kalpak Shah <[email protected]>
---
fs/ext4/inode.c | 4 +++-
fs/ext4/super.c | 6 +++++-
include/linux/ext4_fs.h | 1 +
3 files changed, 9 insertions(+), 2 deletions(-)


Attachments:
ext4_no_version.patch (2.18 kB)

2007-06-14 20:50:17

by Mingming Cao

[permalink] [raw]
Subject: Re: [PATCH 4/6] add noversion mount option

On Thu, 2007-06-14 at 21:26 +0530, Kalpak Shah wrote:
> This patch adds a "noversion" mount option to disable inode version
> updates.

Can you explain a bit more why we need this mount option? Is it because
of performance concern?

Mingming

2007-06-14 21:42:44

by Andreas Dilger

[permalink] [raw]
Subject: Re: [PATCH 4/6] add noversion mount option

On Jun 14, 2007 13:50 -0700, Mingming Cao wrote:
> On Thu, 2007-06-14 at 21:26 +0530, Kalpak Shah wrote:
> > This patch adds a "noversion" mount option to disable inode version
> > updates.
>
> Can you explain a bit more why we need this mount option? Is it because
> of performance concern?

This is the "disable i_version updates for Lustre" option we previously
agreed on in the concall.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.

2007-06-14 21:53:21

by Kalpak Shah

[permalink] [raw]
Subject: Re: [PATCH 4/6] add noversion mount option

On Thu, 2007-06-14 at 13:50 -0700, Mingming Cao wrote:
> On Thu, 2007-06-14 at 21:26 +0530, Kalpak Shah wrote:
> > This patch adds a "noversion" mount option to disable inode version
> > updates.
>
> Can you explain a bit more why we need this mount option? Is it because
> of performance concern?

Lustre requires the counter to be globally unique on the entire
filesystem and hence needs to turnoff per-inode version updates. So in
the interlock meeting on 5th June, Ted has suggested the this approach.

"- Ted suggested having a flag in the superblock for i_version, with an
additional option of having a global counter for Lustre's requirements.
i_version would be on by default, but give users who do not use the
feature the option to turn it off and avoid any performance impact."

Thanks,
Kalpak.

>
> Mingming
>
> -
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2007-06-14 22:28:44

by Mingming Cao

[permalink] [raw]
Subject: Re: [PATCH 4/6] add noversion mount option

On Fri, 2007-06-15 at 03:22 +0530, Kalpak Shah wrote:
> On Thu, 2007-06-14 at 13:50 -0700, Mingming Cao wrote:
> > On Thu, 2007-06-14 at 21:26 +0530, Kalpak Shah wrote:
> > > This patch adds a "noversion" mount option to disable inode version
> > > updates.
> >
> > Can you explain a bit more why we need this mount option? Is it because
> > of performance concern?
>
> Lustre requires the counter to be globally unique on the entire
> filesystem and hence needs to turnoff per-inode version updates. So in
> the interlock meeting on 5th June, Ted has suggested the this approach.
>
> "- Ted suggested having a flag in the superblock for i_version, with an
> additional option of having a global counter for Lustre's requirements.
> i_version would be on by default, but give users who do not use the
> feature the option to turn it off and avoid any performance impact."
>
Right. Somehow my impression is that we have agreed to do this through
tune2fs. I was just double checking if the mount option is for the
Lustre use. Anyway, I am fine with a mount option.


> Thanks,
> Kalpak.
>
> >
> > Mingming
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
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