On 09/30/2015 12:35 PM, Boaz Harrosh wrote: > On 09/30/2015 12:28 PM, Hannes Reinecke wrote: > <> >> Pushing things into the background is typically not the best of >> ideas; actually I've been running into issues with udev not being >> complete by the time the next round is started. So more often than >> not I would be greeted with messages: >> >> 'write: no such file or directory' >> >> when executing this line. Removing the '&' at the end made this >> warning go away. >> >> And actually I'm not sure if the above script is a valid testcase; > > So are you saying it is allowed to crash the Kernel with a crappy > script? > I'm just saying there might be race conditions lurking in the sysfs code which just now came to light, without the patch being the actual culprit. >> from what I've seen there is no locking / reference counting when >> accessing sysfs attributes. So as soon as you _can_ access the sysfs >> attribute it is implicitly assumed to be valid. >> In your case you will be _removing_ the sysfs attribute even though >> it is still accessed, which of course will crash. >> > > Is that allowed? for usermode script to race and crash the Kernel? > > From the original email it sounds like this used to be fine and it > now crashes (with the &) > Yeah, it is not meant to be as an excuse. Just an observation. I still would like to see the results with my ALUA handler update; there's a fair chance the issue is solved with that. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
