Messages in this thread | | | Date | Mon, 3 Dec 2012 16:54:36 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] block: Restore /proc/partitions to not display non-partitionable removable devices |
| |
On Mon, 03 Dec 2012 18:40:32 -0600 Josh Hunt <johunt@akamai.com> wrote:
> On 12/03/2012 06:06 PM, Andrew Morton wrote: > > On Mon, 19 Nov 2012 18:56:49 -0800 > > Josh Hunt <johunt@akamai.com> wrote: > > > >> We found with newer kernels we started seeing the cdrom device showing > >> up in /proc/partitions, but it was not there before. Looking into this I found > >> that commit d27769ec... block: add GENHD_FL_NO_PART_SCAN introduces this change > >> in behavior. It's not clear to me from the commit's changelog if this change was > >> intentional or not. This comment still remains: > >> /* Don't show non-partitionable removeable devices or empty devices */ > >> so I've decided to send a patch to restore the behavior of not printing > >> unpartitionable removable devices. > > > > d27769ec was merged in August 2011, so I after all this time, your fix > > could be viewed as "changing existing behaviour". > > > > So perhaps it would be best to leave things alone. Is there any > > particular problem with the post-Aug, 2011 behaviour? > > > > We caught this by a script that parses /proc/partitions and made some > assumptions about the contents therein. It had worked fine up until when > this behavior changed. We were able to modify our script to get what we > needed. > > The patch was meant to do two things: 1) understand if this was an > unintended change and 2) if so, propose a solution to resolve it. Since > the comment was left in the source I believe either a) my patch should > be applied or b) a new patch with the comment removed should be put in > since it's no longer correct. I did not think this type of change to > kernel abi was generally acceptable. > > While the commit is over a year old, it changes behavior which had been > in tact for a while (years?) from what I can tell. We were running 3.0 > with stable updates until we upgraded to 3.2 and hit this. Neither of > these are what I would consider "old" kernels. >
Yes, this is difficult. Removing existing entries is more likely to cause damage than adding new ones, so I suspect the safest approach is to just leave things as they now are.
In which case yes, we should repair that comment. ie: change it to a comment which explains *why* we display removable devices. Unlike the existing comment which tells us "what" but not "why", when "why" is what we wanted to know, sigh.
| |