Messages in this thread | | | Subject | Re: UBIFS: Oops while rebooting 2.6.34-rc6 | From | Artem Bityutskiy <> | Date | Fri, 07 May 2010 18:23:46 +0300 |
| |
On Fri, 2010-05-07 at 15:16 +0200, Daniel Mack wrote: > Hi, > > We've had a kernel Oops today when rebooting an ARM PXA based machine > while file I/O via SSH was outstanding. > > Daniel > > # reboot > # [ 671.190085] UBIFS: un-mount UBI device 0, volume 1 > The system is going down NOW! > Sent SIGTERM to all processes > [ 672.083833] Unable to handle kernel NULL pointer dereference at virtual address 000000ac > [ 672.094587] pgd = c0004000 > [ 672.097301] [000000ac] *pgd=00000000 > [ 672.100850] Internal error: Oops: 817 [#1] > [ 672.104919] last sysfs file: /sys/devices/platform/spi_gpio.0/spi0.2/value
It's Firday, and I want to go home, so here is another quick idea for you where to dig.
When the system reboots it re-mounts the FS to RO mode, usually. And there is some emergency remount business (see do_emergency_remount()), which will re-mount the FS even if there are files opened for writing.
So, if there is a UBIFS or VFS bug, and somehow one process is in make_reservation() and is about to write something, and another process managed to re-mount the FS to R/O mode, then we may ooops, because UBIFS frees these 'wbuf' objects when it is mounted to R/O (see ubifs_remount_ro()).
So, inject printks to ubifs_remount_ro() to check this theory.
Have a nice weekend and bughunting!
-- Best Regards, Artem Bityutskiy (Артём Битюцкий)
-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |