Date: Fri, 23 May 2008 19:40:04 GMT From: Volker Werth <vwe@freebsd.org> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/123908: panic: vinvalbuf: dirty bufs Message-ID: <200805231940.m4NJe4uA071286@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
The following reply was made to PR kern/123908; it has been noted by GNATS. From: Volker Werth <vwe@freebsd.org> To: =?ISO-8859-1?Q?Nejc_=A9koberne?= <nejc@skoberne.net> Cc: bug-followup@FreeBSD.org Subject: Re: kern/123908: panic: vinvalbuf: dirty bufs Date: Fri, 23 May 2008 21:12:41 +0200 On 05/22/08 23:43, Nejc Škoberne wrote: > Hi, > > I really don't want to bother and waste your time. I will just briefly > express my > humble opinion. To me, if kernel panics when I do something a regular > user could > do by accident (i.e. unplug the USB stick while still mounted), this is > worth fixing. > Is there really no other way for kernel to let the user know he did > something stupid > than panicking? I understand this should be the behaviour when > unplugging some more > "fixed" device like non-hotplug hard drive, RAM memory, or CPU :). But > for USB sticks? > Were not they created for the purpose to be easily removable and > portable? I also > understand that FreeBSD uses the same subsystem (if I understand > correctly) for > USB devices as for SCSI devices (i.e. also SCSI hard drives), that's why > we see USB > devices as /dev/da*. > > On the other hand, the panic in this case doesn't happen when the user > unplugs the USB > device while mounted, but when it is plugged back in after it was > unplugged (while > mounted). Maybe you are saying that after doing something "prohibited" > like unplugging > the USB stick when still mounted leaves the system (without the user > being explicitly > notified?) in a completely unstable and undefined state (plugging the > device back is, I > assume an always legal operation)? If so (since the system does not > _yet_ panick when > the device is unplugged), then I guess the user should be somehow > notified about this > condition so he can manually reboot the system and bring it back to a > consistent and > defined state. > > So what I don't know is: is this behaviour recognized as a bug at all? > Or is it just > normal behaviour all users should live with? > > Thanks for your time, > Nejc > Nejc, I thought I might have been as clear as possible in my PR closing note. The behavior you've seen (a kernel panic while a device with active mounts is being removed from the system) is a bug - this is not questionable. The reason for closing your PR is really simple (and I already told you about that): The problem is well known, which means, it's been reported many, many times. As we (the bugbusting team) need to keep the house clean (which is by itself a hard job), we can not accept and we do not want to have 20 open PRs, or how often an issue ever caused a panic on an user machine, for the real same issue. If you find a problem, first please check Jeremy's "commonly reported issues" page at: http://wiki.freebsd.org/JeremyChadwick/Commonly_reported_issues Note to Jeremy (do you read?): Your wiki page is not linked on the main wiki page. Can you please put a link under the bugbusting section? You'll find your issue also listed on that commonly reported issues page. If an issue you're experiencing is not listed there, please check our GNATS database (try it with different search parameters to make sure, it's not already reported). If an issue already has been reported and you think you can contribute valuable information for the bugbusting team to analyze or the maintainers to fix an issue, please file a followup to an already filed PR. Often it might help to ask on a mailing list first and have a discussion about an issue before filing a PR which might not get attention for some time and die old later. Sorry to have you confused so much, but please understand we're currently facing 5300 open problem tickets and we can not deal with duplicates. Thank you for your understanding! Volker
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200805231940.m4NJe4uA071286>