[RFC PATCH 0/3] Moving lustre procfs stuff to sysfs & questions.

[RFC PATCH 0/3] Moving lustre procfs stuff to sysfs & questions.

[green]

From: Oleg Drokin <green@linuxhacker.ru>

Greg, I wonder if you can take at least a brief look and tell me if this
is the direction you were envisioning wrt this particular cleanup.

It's not all-inclusive, but I have a long flight tomorrow so
if the direction is right, I can convert more of this stuff.

This does not touch some of the multi-value stuff that would probably
need to move to debugfs or other places, that would be a next step.

Additionally some questions:
I know sysfs is supposedly 1 file 1 value, though I see some exceptions, e.g.:
# cat /sys/kernel/vmcoreinfo 
2b57500 1024

So we have this /proc/fs/lustre/devices that prints status of all
"lustre internal devices (or obd for short)" like this:
# cat /proc/fs/lustre/devices 
  0 UP mgc MGC192.168.10.226@tcp d6815182-b36d-c4ba-6aa6-065aeb9e9769 5
  1 UP lov lustre-clilov-ffff8800bd617800 32be3f55-891e-ed82-cae9-6add0770d503 4
...

Obviously I cannot retain it as a single file, but do I really need to
create a tree that would look like:
/sys/fs/lustre/obd/[1...]/{status,name,type,uuid,refcount}
(or possibly even /sys/devices/virtual/lustre_obd/... )
or can I get away with just
/sys/fs/lustre/obd/[1...] files where there's one line per obd like:
  0 UP mgc MGC192.168.10.226@tcp d6815182-b36d-c4ba-6aa6-065aeb9e9769 5
(frankly, I have not figured out yet how to dynamically add files
to sysfs dir).

What about /proc/sys stuff - /proc/sys/lustre and /proc/sys/lnet?
Hopefully it's ok to leave those where they are?

Also I found that cgroup does calls into kernfs directly, gaining
ability to register seq_file files and otherwise do all sorts of
stuff that would be cool to do from lustre too ;)

These patches compile and run, but I imagine it's not a great idea
to merge them yet.

Thanks.

Oleg Drokin (3):
  staging/lustre: Generic helpers for sysfs
  staging/lustre: Move /proc/fs/lustre root level files to sysfs
  staging/lustre/llite: move some procfs files to sysfs

 .../staging/lustre/lustre/include/lprocfs_status.h |  26 +++
 .../staging/lustre/lustre/llite/llite_internal.h   |   4 +
 drivers/staging/lustre/lustre/llite/llite_lib.c    |   7 +-
 drivers/staging/lustre/lustre/llite/lproc_llite.c  | 190 ++++++++++++---------
 drivers/staging/lustre/lustre/llite/super25.c      |  11 +-
 .../lustre/lustre/obdclass/linux/linux-module.c    | 116 ++++++++-----
 .../lustre/lustre/obdclass/lprocfs_status.c        |  24 +++
 7 files changed, 246 insertions(+), 132 deletions(-)

-- 
2.1.0

Re: [RFC PATCH 0/3] Moving lustre procfs stuff to sysfs & questions.

[Greg Kroah-Hartman]

On Sat, May 02, 2015 at 11:10:05PM -0400, green@linuxhacker.ru wrote:
> From: Oleg Drokin <green@linuxhacker.ru>
> 
> Greg, I wonder if you can take at least a brief look and tell me if this
> is the direction you were envisioning wrt this particular cleanup.
> 
> It's not all-inclusive, but I have a long flight tomorrow so
> if the direction is right, I can convert more of this stuff.
> 
> This does not touch some of the multi-value stuff that would probably
> need to move to debugfs or other places, that would be a next step.
> 
> Additionally some questions:
> I know sysfs is supposedly 1 file 1 value, though I see some exceptions, e.g.:
> # cat /sys/kernel/vmcoreinfo 
> 2b57500 1024
> 
> So we have this /proc/fs/lustre/devices that prints status of all
> "lustre internal devices (or obd for short)" like this:
> # cat /proc/fs/lustre/devices 
>   0 UP mgc MGC192.168.10.226@tcp d6815182-b36d-c4ba-6aa6-065aeb9e9769 5
>   1 UP lov lustre-clilov-ffff8800bd617800 32be3f55-891e-ed82-cae9-6add0770d503 4
> ...
> 
> Obviously I cannot retain it as a single file, but do I really need to
> create a tree that would look like:
> /sys/fs/lustre/obd/[1...]/{status,name,type,uuid,refcount}
> (or possibly even /sys/devices/virtual/lustre_obd/... )
> or can I get away with just
> /sys/fs/lustre/obd/[1...] files where there's one line per obd like:
>   0 UP mgc MGC192.168.10.226@tcp d6815182-b36d-c4ba-6aa6-065aeb9e9769 5
> (frankly, I have not figured out yet how to dynamically add files
> to sysfs dir).

Either make a tree of kobjects, or individual files, but not one big
file, that's not acceptable for sysfs, sorry.

> What about /proc/sys stuff - /proc/sys/lustre and /proc/sys/lnet?
> Hopefully it's ok to leave those where they are?

Nope, please remove.  If you aren't a process value, you can't add new
proc files.

> Also I found that cgroup does calls into kernfs directly, gaining
> ability to register seq_file files and otherwise do all sorts of
> stuff that would be cool to do from lustre too ;)

If you want to make lustrefs, be my guest, you can do whatever you want
in that, using kernfs, but that's not ok for sysfs, sorry.

thanks,

greg k-h

Re: [RFC PATCH 0/3] Moving lustre procfs stuff to sysfs & questions.

[Oleg Drokin]

On May 3, 2015, at 2:15 PM, Greg Kroah-Hartman wrote:

>> Also I found that cgroup does calls into kernfs directly, gaining
>> ability to register seq_file files and otherwise do all sorts of
>> stuff that would be cool to do from lustre too ;)
> If you want to make lustrefs, be my guest, you can do whatever you want
> in that, using kernfs, but that's not ok for sysfs, sorry.

If only __kernfs_create_file was exported… ;)

Otherwise you cannot really do that from modules.

Bye,
    Oleg--
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