Re: FreeBSD 9: fdisk -It crashes kernel

看板FB_stable作者時間12年前 (2013/04/27 13:33), 編輯推噓0(0推 0噓 0→)
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On Apr 25, 2013, at 10:58 AM, Jeremy Chadwick <jdc@koitsu.org> wrote: > On Thu, Apr 25, 2013 at 09:06:49AM -0500, Guy Helmer wrote: >> Encountered a surprise when my disk resizing rc.d script caused FreeBSD = 9.1-STABLE to crash. I used "fdisk -It ada0" to determine what the availabl= e size of the disk (which happened to be the root disk), and on FreeBSD 9.1= the kernel comes crashing down: >> = >> + fdisk -It ada0 >> + /rescue/sed -En 's,.*start ([0-9]+).*size ([0-9]+).*,\1 + \2,p' >> vnode_pager_getpages: I/O read error >> vm_fault: pager read error, pid 65 (fdisk) >> pid 65 (fdisk), uid 0: exited on signal 11 >> eval: arithmetic expression: expecting primary: "" >> Entropy harvesting: point_to_pointeval: date: Device not configured >> eval: df: Device not configured >> eval: dmesg: Device not configured >> cat: /bin/ls: Device not configured >> kickstart. >> eval: cannot open /etc/fstab: Device not configured >> eval: cannot open /etc/fstab: Device not configured >> eval: swapon: Device not configured >> Warning! No /etc/fstab: skipping disk checks >> fstab: /etc/fstab:0: Device not configured >> = >> Fatal trap 12: page fault while in kernel mode >> cpuid =3D 1; apic id =3D 01 >> fault virtual address =3D 0x0 >> fault code =3D supervisor read, page not present >> instruction pointer =3D 0x20:0xc0825fc4 >> stack pointer =3D 0x28:0xc5a088c8 >> frame pointer =3D 0x28:0xc5a08914 >> code segment =3D base 0x0, limit 0xfffff, type 0x1b >> =3D DLP 0, pres 1, def32 1, gran 1 >> processor eflags =3D interrupt enabled, resume, IOPL =3D 0 >> current process =3D 91 (mount) >> [ thread pid 91 tid 100056 ] >> Stopped at g_access+0x24: mlvl 0(%ebx),%eax >> db> where >> Tracing pid 91 tid 100056 td 0xc84c42f0 >> g_access(c8481d34,0,1,1,0,=85) at g_access+0x24/frame 0xc5a08914 >> ffs_mount(c8481d34,c0d78380,2,c5a08c00,c829ae6c,=85) af ffs_mount+0xf74/= frame 0xc5a08a34 >> vfs_donmount(c84c42f0,10000,0,c84cf200,c84cf200,=85) at vfs_donmount+0x1= 423/frame 0xc5a08c24 >> sys_nmount(c84c42f0,c5a08ccc,c5a08cc4,1010006,c5a08d08,=85) at sys_nmoun= t+0x7f/frame 0xc5a08c48 >> syscall(c5a08d08) at syscall+0x443/frame 0xc508cfc >> Xint0x80_syscall() at Xint0x80_syscall+0x21/frame 0xc5a08cfc >> --- syscall (378, FreeBSD ELF32, sys_nmount), eip =3D 0x480d5feb, esp = =3D 0xbfbfce1c, ebp =3D 0xbfbfd378 --- >> = >> I'll fix my script to not do this, but it seems odd that fdisk -It can m= ake the disk "go away". > = > Please provide a full, unmodified copy of your script. > = > What's confusing to me is that after your sed call (which I don't even > understand, because it doesn't appear to be operating on anything except > stdin/stdout, and we don't know what that is -- again, show the script), > the kernel starts outputting indications that the root disk/filesystem > or its related metadata disappeared: > = >> vnode_pager_getpages: I/O read error >> vm_fault: pager read error, pid 65 (fdisk) >> pid 65 (fdisk), uid 0: exited on signal 11 > = > Except the kernel stack trace indicates something called sys_nmount(), > which called vfs_donmount(), which called ffs_mount(), which calls > g_access(). All of those scream to me "someone tried to mount > something". fdisk does not do mounting. Right, which is why I copied the entire screen output -- it appears to me t= hat the rc scripts had stumbled on until the kernel panicked. > = > fdisk also shouldn't be writing to LBA 0 (the MBR) if you used -I -t. > I've been staring at fdisk.c for about 20 minutes now and I can't work > out a situation where -I -t would cause the MBR to be rewritten > actively. > = > The only GEOM calls I see in fdisk.c that would get called are > g_device_path(), g_open(), and g_close(). Actual device I/O uses read() > and write() (only in write_s0() which shouldn't be called). > = > Furthermore, GEOM has foot-shooting-prevention mechanisms in place (I'm > talking about kern.geom.debugflags) to keep LBA 0 from being modified. > Is your script setting that sysctl to 16/0x10 blindly? Ahem. No. The script is intended only to work for drives other than the one conta= ining the boot partition. > = > It would also help if you could state exactly what 9.1-STABLE source > you're using; if using svn provide revision (rXXXXXX), else provide > uname -a output. rev 249788 > = > Finally: I would suggest using gpart(8) instead going forward. This is > a separate recommendation though; if somehow I'm overlooking something > in fdisk.c where writes to LBA 0 really do happen, then that needs to > get fixed. But gpart(8) is what you should use in general these days > anyway. > = Seems like gpart was giving me some frustration with earlier versions of Fr= eeBSD (7, I think) so I went with fdisk instead. Might work OK now... I have included the full script below. #!/bin/sh # # PROVIDE: growfs_vm # REQUIRE: root # BEFORE: disks # # Check the disks and partitions on them to see whether partitions # need to be resized. # # Copyright 2011 Palisade Systems, Inc. # # $Id: growfs_vm.sh 6687 2012-06-13 19:53:29Z ghelmer $ .. /etc/rc.subr prefix=3D"/usr/local" name=3D"growfs_vm" rcvar=3D$(set_rcvar) load_rc_config "${name}" growfs_vm_enable=3D${growfs_vm_enable-"YES"} start_cmd=3D"growfs_vm_start" growfs_vm_min_increase=3D${growfs_vm_min_increase-"16384"} SED=3D/rescue/sed disk_mounted() { local DISK=3D$1 local mounts mounts=3D$(mount | $SED -En -e "s,^/dev/(${DISK})s[0-9]+[a-z]+ on .*,\1= ,p") if [ -z "$mounts" ]; then return 1 fi return 0 } grow_disk() { local DISK=3D$1 local physsize local curroff local currsize local delta local part local bsd_part local old_label local new_label # The last partititon offset + size is the disk size. physsize=3D$(($(fdisk -It $DISK | $SED -En 's,.*start ([0-9]+).*size ([= 0-9]+).*,\1 + \2,p'))) eval $(fdisk -v $DISK | $SED -En 's,.*start ([0-9]+).*size ([0-9]+).*,c= urroff=3D\1 currsize=3D\2,p') delta=3D$(($physsize - $curroff - $currsize)) if [ $delta -le $growfs_vm_min_increase ]; then echo "No change in size for disk ${DISK}: delta ${delta} <=3D min ${growfs= _vm_min_increase}" return 0 fi # Get the index of the last FreeBSD partition on the disk. part=3D$(gpart show $DISK | $SED -En 's,^ *[0-9]+ +[0-9]+ +(4) +freebsd= .*,\1,p') if [ -z "$part" ]; then part=3D$(gpart show $DISK | $SED -En 's,^ *[0-9]+ +[0-9]+ +(3) +freebsd .*= ,\1,p') fi if [ -z "$part" ]; then part=3D$(gpart show $DISK | $SED -En 's,^ *[0-9]+ +[0-9]+ +(2) +freebsd .*= ,\1,p') fi if [ -z "$part" ]; then part=3D$(gpart show $DISK | $SED -En 's,^ *[0-9]+ +[0-9]+ +(1) +freebsd .*= ,\1,p') fi # Extend the partition to the end of the disk. gpart resize -i $part $DISK if [ "$?" -ne 0 ]; then echo "gpart resize -i $part $DISK failed" return 1 fi # Now, find the last BSD partition and extend it. old_label=3D$(bsdlabel "${DISK}s${part}") bsd_part=3D$(echo "$old_label" | $SED -En 's,^ *(g): +[0-9]+ +[0-9]+ +4= \.2BSD .*,\1,p') if [ -z "$bsd_part" ]; then bsd_part=3D$(echo "$old_label" | $SED -En 's,^ *(f): +[0-9]+ +[0-9]+ +4\.2= BSD .*,\1,p') fi if [ -z "$bsd_part" ]; then bsd_part=3D$(echo "$old_label" | $SED -En 's,^ *(e): +[0-9]+ +[0-9]+ +4\.2= BSD .*,\1,p') fi if [ -z "$bsd_part" ]; then bsd_part=3D$(echo "$old_label" | $SED -En 's,^ *(d): +[0-9]+ +[0-9]+ +4\.2= BSD .*,\1,p') fi # Extend 'c' pseudo-partition and the last BSD partition # to the end of the disk. new_label=3D$(echo "$old_label" | $SED -E \ -e "s,c: ([0-9]+),c: *," \ -e "s,${bsd_part}: ([0-9]+),${bsd_part}: *,") echo "$new_label" | bsdlabel -R "${DISK}s${part}" /dev/stdin if [ "$?" -ne 0 ]; then echo "bsdlabel -R ${DISK}s${part} failed" return 1 fi # Finally, run growfs on the extended partition. growfs -y "${DISK}s${part}${bsd_part}" if [ "$?" -ne 0 ]; then echo "growfs -y ${DISK}s${part}${bsd_part} failed" return 1 fi return 0 } growfs_vm_start() { local maker maker=3D`/bin/kenv smbios.system.maker` if [ "$maker" =3D "VMware, Inc." ]; then echo 'growfs_vm starting.' disks=3D$(gpart show | $SED -En -e 's,=3D> +[0-9]+ +[0-9]+ +([a-z]+[0-9]+)= +MBR .*,\1,p') for disk in $disks; do if disk_mounted $disk; then echo "Disk ${disk} is mounted: skipping" else grow_disk $disk fi done echo 'growfs_vm finished.' mounted_root=3D$(mount | $SED -En -e 's,(^/dev/|^)([a-z]+[0-9a-z]+) on / .= *,\2,p') if [ "$mounted_root" =3D 'cd0' -o "$mounted_root" =3D 'acd0' ]; then # We're running off a boot CD. echo "Finished growfs_vm. Remove virtual CD and reboot." halt fi fi } run_rc_command "$1" _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"
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文章代碼(AID): #1HUsCWbb (FB_stable)
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文章代碼(AID): #1HUsCWbb (FB_stable)