On Sat, 9 Feb 2002, John Baldwin wrote: > On 09-Feb-02 Mikhail Teterin wrote: > > While attempting to ``fdisk fd0.1440''. Or ``fdisk fd0''. Or > > ``newfs_msdos fd0.1440'' with or without the floppy inside :-\ > > With todays or Jan 3rd kernel (my previous upgrade). > > Only use fdisk on hard disks. Still it shouldn't panic. The bdwrite is just > extra garbage, the real panic is due to a NULL pointer dereference:
This is a well known bug in the device layer. I reported it on 2001/12/26 and fixed it locally a little later. See the thread in -current about "panic during fdisk'ing a md(4) device" for patches. > I'm guessing that devsw() is returning NULL here. You could add a KASSERT() to > this macro just before the call to d_strategy() along the lines of > > KASSERT(devsw((bp)->bio_dev) != NULL, ("no devsw for bio")); \ Right. From my original bug report: ! "fdisk /dev/fd0" now causes a null pointer panic in readdisklabel(). ! This is because fdioctl() attempts to construct a (slightly wrong) ! device using dkmodpart(), but dkmodpart() only constructs a half-baked ! device since it only calls makedev(). The device is missing a devsw ! so DEV_STRATEGY() in readdisklabel() panics on it. Bruce To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message