Messages in this thread | | | Date | Fri, 5 Feb 2016 09:34:13 +0100 | From | Johannes Thumshirn <> | Subject | Re: [PATCH 5/6] ibmvscsi: Remove unsupported host config MAD and sysfs interface |
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On Thu, Feb 04, 2016 at 09:48:23AM -0800, Tyrel Datwyler wrote: > On 02/04/2016 12:03 AM, Johannes Thumshirn wrote: > > On Wed, Feb 03, 2016 at 05:28:33PM -0600, Tyrel Datwyler wrote: > >> A VIOSRP_HOST_CONFIG_TYPE management datagram (MAD) has existed in > >> the code for some time. From what information I've gathered from > >> Brian King this was likely implemented on the host side in a SLES 9 > >> based VIOS, which is no longer supported anywhere. Further, it is > >> not defined in PAPR or supported by any AIX based VIOS. > >> > >> Treating as bit rot and removing the sysfs interface and associated > >> host config code accordingly. > > > > Doesn't removing a sysfs interface potentially break userspace code? > > > > In the general case yes, but I feel in this case no. First, Reading from > this config attribute of a vscsi host adapter always returns nothing. > Second, any userspace code using this attribute better be checking for > the existence of config. Just a quick look for > /sys/class/scsi_host/host*/config under other host adapters on my system > I find that attribute doesn't exist for any of them. > > If there is truly enough concern that somebody may actually be accessing > this useless attribute from userspace then we can still strip out the > unsupported code, but leave the attribute and return nothing directly > from the show function.
Which is what I kinda prefer. Slowly deprecate and phase out, but don't break userspace. You never know who is writing some obscure piece of code relaying on some sysfs attribute.
Thanks, Johannes
-- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
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