Re: [PATCH] sysfs: add /sys/dev/{char, block} to lookup sysfs path by major:minor

["Dan Williams" <dan.j.williams@intel.com>]

On Mon, Apr 14, 2008 at 8:13 PM, SL Baur <steve@xemacs.org> wrote:
> On 4/14/08, Dan Williams <dan.j.williams@intel.com> wrote:
>
>  >  This is the second revision of the patch originally posted here:
>  >  http://marc.info/?l=linux-kernel&m=120795638915272&w=2
>  >
>  >  * Fixed up ENOMEM handling in devices_init()
>  >  * Added a short blurb in Documentation/filesystems/sysfs.txt
>  >
>  >   Documentation/filesystems/sysfs.txt |    6 +++++
>  >   drivers/base/core.c                 |   46 ++++++++++++++++++++++++++++++++++-
>  >   2 files changed, 51 insertions(+), 1 deletions(-)
>
>  I've looked this patch over and I have some comments.  The logic looks
>  correct, but there are two ugly lines.
>
>
>  >  @@ -775,6 +783,7 @@ int device_add(struct device *dev)
>  >         struct device *parent = NULL;
>  >         struct class_interface *class_intf;
>  >         int error;
>  >  +       char devt_str[25];
>
>
> >  @@ -925,12 +944,16 @@ void device_del(struct device *dev)
>  >   {
>  >         struct device *parent = dev->parent;
>  >         struct class_interface *class_intf;
>  >  +       char devt_str[25];
>
>  May I ask why `25'?  The only other user of format_dev_t that I could find
>  in a quick grep is md (device-mapper) and they used a hardcoded `15' there.
>  The real problem is format_dev_t and print_dev_t.
>
>  If the only other user of those macros which want to be C inlines with
>  buffer size parameters is md, perhaps now would be a good time to clean
>  them up before adding more users?
>
>  Otherwise, the logic looks O.K.
>

Thanks for looking it over.  To be honest I was iffy about those
buffer sizes as well, and looking closer they are overkill.  Although,
they are smaller than the 32-byte buffer in bsg.c :-). 13-bytes is all
that is needed given a 12-bit major and 20-bit minor.  Care to send a
patch to fix up format_dev_t and print_dev_t?

>  Add my
>  Reviewed-by: SL Baur <steve@xemacs.org>
>  if that is appropriate.
>

Yes, appropriate.

Thanks,
Dan