Date: Sat, 16 May 2015 16:16:23 -0600 From: Ian Lepore <ian@freebsd.org> To: Mattia Rossi <mattia.rossi.mailinglists@gmail.com> Cc: freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: Random Kernel Panic on Dreamplug (FS related) Message-ID: <1431814583.91685.39.camel@freebsd.org> In-Reply-To: <542ABE45.3020402@gmail.com> References: <542559BC.7090100@gmail.com> <20140929040126.GG43300@funkthat.com> <54291B74.5010307@gmail.com> <20140930112937.GU43300@funkthat.com> <542A9EA4.70109@gmail.com> <20140930123010.GZ43300@funkthat.com> <542AB897.3020309@gmail.com> <1412086795.66615.363.camel@revolution.hippie.lan> <542ABE45.3020402@gmail.com>
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On Tue, 2014-09-30 at 16:29 +0200, Mattia Rossi wrote: > Am 30.09.2014 16:19, schrieb Ian Lepore: > > On Tue, 2014-09-30 at 16:05 +0200, Mattia Rossi wrote: > >> Am 30.09.2014 14:30, schrieb John-Mark Gurney: > >>> Mattia Rossi wrote this message on Tue, Sep 30, 2014 at 14:14 +0200: > >>>> Am 30.09.2014 13:29, schrieb John-Mark Gurney: > >>>>> Mattia Rossi wrote this message on Mon, Sep 29, 2014 at 10:42 +0200: > >>>>>> Am 29.09.2014 06:01, schrieb John-Mark Gurney: > >>>>>>> Mattia Rossi wrote this message on Fri, Sep 26, 2014 at 14:19 +0200: > >>>>>>>> This might be part of the weird FFS issues the Dreamplug has and no-one > >>>>>>>> knows why they're happening. > >>>>>>> Are you running w/ FFS journaling? If so, try turning it off, but > >>>>>>> keeping softupdates on.. > >>>>>> No journaling, no softupdates. I'll try enabling softupdates next time. > >>>>>> don't know if it will panic though > >>>>>>>> data_abort_handler() at data_abort_handler+0x5c0 > >>>>>>>> pc = 0xc0de7a28 lr = 0xc0dd711c (exception_exit) > >>>>>>>> sp = 0xde019898 fp = 0xde019a20 > >>>>>>>> r4 = 0xffffffff r5 = 0xffff1004 > >>>>>>>> r6 = 0xc3f3f6c0 r7 = 0x00001000 > >>>>>>>> r8 = 0xc443e880 r9 = 0x00000000 > >>>>>>>> r10 = 0xc3d69000 > >>>>>>>> exception_exit() at exception_exit > >>>>>>>> pc = 0xc0dd711c lr = 0xc0d53828 (ffs_truncate+0xaa8) > >>>>>>>> sp = 0xde0198e8 fp = 0xde019a20 > >>>>>>>> r0 = 0xd0238120 r1 = 0x00000e60 > >>>>>>>> r2 = 0x00000000 r3 = 0x00000000 > >>>>>>>> r4 = 0x00000120 r5 = 0x00000000 > >>>>>>>> r6 = 0xc3f3f6c0 r7 = 0x00001000 > >>>>>>>> r8 = 0xc443e880 r9 = 0x00000000 > >>>>>>>> r10 = 0xc3d69000 r12 = 0xd0238120 > >>>>>>>> memset() at memset+0x48 > >>>>>>>> pc = 0xc0de521c lr = 0xc0d53828 (ffs_truncate+0xaa8) > >>>>>>>> sp = 0xde0198e8 fp = 0xde019a20 > >>>>>>>> Unwind failure (no registers changed) > >>>>>>> No more beyond this? If you could run addr2line on 0xc0d53828 so > >>>>>>> that we know where in ffs_truncate it's failing, that'd be very > >>>>>>> nice... > >>>>>> So I was trying to save the coredump in order to reboot and run > >>>>>> addr2line, but that failed: > >>>>>> > >>>>>> Physical memory: 504 MB > >>>>>> Dumping 67 MB:(da0:umass-sim0:0:0:0): WRITE(10). CDB: 2a 00 01 d5 1f20 > >>>>>> 00 00 01 00 <sip:2000000100> > >>>>>> (da0:umass-sim0:0:0:0): CAM status: Resource Unavailable > >>>>>> (da0:umass-sim0:0:0:0): Error 5, Retries exhausted > >>>>>> Aborting dump due to I/O error. > >>>>>> > >>>>>> ** DUMP FAILED (ERROR 5) ** > >>>>>> > >>>>>> So I guess this error is related to the CAM errors I'm getting from time > >>>>>> to time. I was hoping that those errors were related to the INVARIANTS > >>>>>> option that slowed down the system and thus might have triggered CAM > >>>>>> errors, but obviously the SD Card seems to be the real issue here. > >>>>>> So no crashdump for further analysis. > >>>>> That's fine.. w/ the addr2line we have some lines to explore... > >>>>> > >>>>>> Interestingly the CAM errors didn't show up on the terminal as other > >>>>>> times, the kernel just panicked straight away. > >>>>> Hmm.. that is odd.. someone who knows the SD card layer should look > >>>>> at this part... It could be that the SD card driver doesn't handle > >>>>> dumping (there is this global flag that gets set) properly and the driver > >>>>> needs to behave differently when it's set... > >>>> I also need to grab a new SD card, just to make sure it's really not the > >>>> card. > >>>> > >>>>>> But I've got the addr2line output, even though I'm not sure it makes any > >>>>>> difference: > >>>>>> > >>>>>> addr2line -f -e /mnt/kernel.debug 0xc0d53828 > >>>>>> > >>>>>> ffs_truncate > >>>>>> /usr/devel/dreamplug/sys/ufs/ffs/ffs_inode.c:321 > >>>>> can you give me the contents of the line? and a few lines of context > >>>>> around it? In HEAD's source, this is DOINGASYNC, and there is no call > >>>>> to memset, nor a variable assignment that would result in memset being > >>>>> called... > >>>> Same here.. The file hasn't been changed in a while (Fri, 31 May 2013): > >>>> > >>>> ip->i_size = length; > >>>> DIP_SET(ip, i_size, length); > >>>> if (bp->b_bufsize == fs->fs_bsize) > >>>> bp->b_flags |= B_CLUSTEROK; > >>>> if (flags & IO_SYNC) > >>>> bwrite(bp); > >>>> 321: else if (DOINGASYNC(vp)) > >>>> bdwrite(bp); > >>>> else > >>>> bawrite(bp); > >>>> ip->i_flag |= IN_CHANGE | IN_UPDATE; > >>>> return (ffs_update(vp, !DOINGASYNC(vp))); > >>>> > >>>> No idea what's going on. > >>> ok, could you send me the output of objdump -dSl, but you only need > >>> to include the part from XXXXX <ffs_truncate>: to the next XXX<func>: > >>> line... probably off list as it'll be quite long... > >> I'm sorry, but given that I just broke all my working worlds using fsck, > >> I'm not going to be able to do that until I'm back from holidays.... > >> currently working on the stuff remotely and after today's work day, I'm > >> not going to be able to get my hands on the dreamplug. > >> > >> > > BTW, for anyone playing with this problem, step one is to edit > > your /etc/fstab and set the fsck pass number to 0 for all filesystems. > > There's a risk of filesystem corruption after a crash, but it's smaller > > than the 100% corruption rate of letting fsck run. :) > > > Of course! Great idea :-) Sometimes just can't think of the right tweak > to save a lot of pain... > > Anyhow, I just found out, that I was rebooting the dreamplug from the sd > card instead of the usb stick the whole time, and the usb stick hasn't > been damaged enough by fsck, so it actually booted :-) I'll send the > objdump soon. A (very) late update on this.... It looks like we may have tracked the change that started all this down to the introduction of unmapped IO, almost 2 years ago now. I still can't find the root cause, but I think disabling unmapped IO on armv4/5 is a viable workaround, which Warner committed this morning as r283014. --Ian
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