Bug#589413: mdadm: Segmentation fault when converting to RAID6 from RAID5

Björn Påhlsson belorn at fukt.bsnet.se
Sat Jul 17 13:49:22 UTC 2010 

Package: mdadm
Version: 3.1.2-2
Severity: normal

Assuming /dev/md0 is not used, the following commands can be used to
reproduce a segmentation fault in the mdadm command:

# for a in dev0 dev1 dev2 dev3; do dd if=/dev/zero count=256 bs=$((1024*1024)) of="$a"; done
# for a in 0 1 2 3; do losetup /dev/loop$a dev$a; done
# mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/loop0 /dev/loop1 /dev/loop2
# mkfs -t ext3 /dev/md0		# Just to make it sync
# mdadm --verbose /dev/md0 --add /dev/loop3
# mdadm --verbose --grow /dev/md0 --level=raid6 --raid-devices=4

The output of that last command is:

mdadm level of /dev/md0 changed to raid6
Segmentation fault

And the contents of /proc/mdstat is:
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid6 loop3[4](S) loop2[3] loop1[1] loop0[0]
      523264 blocks super 1.2 level 6, 512k chunk, algorithm 18 [4/3] [UUU_]

unused devices: <none>

/Björn

-- Package-specific info:
--- mdadm.conf
DEVICE partitions
CREATE owner=root group=disk mode=0660 auto=yes
HOMEHOST <system>
MAILADDR root

--- /etc/default/mdadm
INITRDSTART='all'
AUTOSTART=true
AUTOCHECK=true
START_DAEMON=false
DAEMON_OPTIONS="--syslog"
VERBOSE=false

--- /proc/mdstat:
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md0 : active raid6 loop3[4](S) loop2[3] loop1[1] loop0[0]
      523264 blocks super 1.2 level 6, 512k chunk, algorithm 18 [4/3] [UUU_]
      
unused devices: <none>

--- /proc/partitions:
major minor  #blocks  name

   8        0  117220824 sda
   8        1     248976 sda1
   8        2          1 sda2
   8        5   97458291 sda5
   8        6     248832 sda6
   8        7   19262464 sda7
 254        0   97457263 dm-0
 254        1   95453184 dm-1
 254        2    2002944 dm-2
   7        0     262144 loop0
   7        1     262144 loop1
   7        2     262144 loop2
   7        3     262144 loop3
   7        4     262144 loop4
   9        0     523264 md0

--- LVM physical volumes:
  PV         VG     Fmt  Attr PSize  PFree
  /dev/dm-0  braxen lvm2 a-   92.94g    0 
--- mount output
/dev/dm-1 on / type ext3 (rw,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
/dev/sda1 on /boot type ext2 (rw)
overflow on /tmp type tmpfs (rw,size=1048576,mode=1777)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)

--- initrd.img-2.6.34-1-amd64:
cpio: write error: No space left on device

gzip: stdout: Broken pipe

--- initrd's /conf/conf.d/md:
no conf/md file.

--- /proc/modules:
dm_crypt 10736 1 - Live 0xffffffffa0268000
raid10 18553 0 - Live 0xffffffffa025d000
raid456 45132 1 - Live 0xffffffffa024a000
async_raid6_recov 5242 1 raid456, Live 0xffffffffa0243000
async_pq 3551 2 raid456,async_raid6_recov, Live 0xffffffffa023d000
raid6_pq 77179 2 async_raid6_recov,async_pq, Live 0xffffffffa0224000
async_xor 2550 3 raid456,async_raid6_recov,async_pq, Live 0xffffffffa021e000
async_memcpy 1206 2 raid456,async_raid6_recov, Live 0xffffffffa0211000
async_tx 1774 5 raid456,async_raid6_recov,async_pq,async_xor,async_memcpy, Live 0xffffffffa020b000
raid1 18769 0 - Live 0xffffffffa0200000
raid0 5541 0 - Live 0xffffffffa01f9000
multipath 6083 0 - Live 0xffffffffa01f2000
linear 3495 0 - Live 0xffffffffa01ec000
md_mod 78646 6 raid10,raid456,raid1,raid0,multipath,linear, Live 0xffffffffa01ce000
dm_mirror 11833 0 - Live 0xffffffffa01c5000
dm_region_hash 6816 1 dm_mirror, Live 0xffffffffa01bd000
dm_log 7693 2 dm_mirror,dm_region_hash, Live 0xffffffffa01b6000
dm_mod 55398 11 dm_crypt,dm_mirror,dm_log, Live 0xffffffffa019d000

--- /var/log/syslog:

--- volume detail:
/dev/sda is not recognised by mdadm.
/dev/sda1 is not recognised by mdadm.
/dev/sda2 is not recognised by mdadm.
/dev/sda5 is not recognised by mdadm.
/dev/sda6 is not recognised by mdadm.
/dev/sda7 is not recognised by mdadm.

--- /proc/cmdline
BOOT_IMAGE=/vmlinuz-2.6.34-1-amd64 root=/dev/mapper/braxen-root ro quiet

--- grub2:
set root='(hd0,msdos1)'
set root='(hd0,msdos1)'
set root='(hd0,msdos1)'
	set root='(hd0,msdos1)'
	linux	/vmlinuz-2.6.34-1-amd64 root=/dev/mapper/braxen-root ro  quiet
	set root='(hd0,msdos1)'
	linux	/vmlinuz-2.6.34-1-amd64 root=/dev/mapper/braxen-root ro single 
	set root='(hd0,msdos1)'
	linux	/vmlinuz-2.6.32-5-amd64 root=/dev/mapper/braxen-root ro  quiet
	set root='(hd0,msdos1)'
	linux	/vmlinuz-2.6.32-5-amd64 root=/dev/mapper/braxen-root ro single 
	set root='(hd0,msdos1)'
	set root='(hd0,msdos1)'
	set root='(hd0,msdos1)'
	set root='(hd0,msdos1)'
set root=(hd0,6)

--- udev:
ii  udev           160-1          /dev/ and hotplug management daemon
4a574fcd059040d33ea18a8aa605a184  /lib/udev/rules.d/64-md-raid.rules

--- /dev:
brw-rw---- 1 root disk 9, 0 Jul 17 15:35 /dev/md0

/dev/disk/by-id:
total 0
lrwxrwxrwx 1 root root  9 Jul 17 15:27 ata-SAMSUNG_HM121HI_S11JJD0P711641 -> ../../sda
lrwxrwxrwx 1 root root 10 Jul 17 12:51 ata-SAMSUNG_HM121HI_S11JJD0P711641-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jul 17 12:51 ata-SAMSUNG_HM121HI_S11JJD0P711641-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Jul 17 12:51 ata-SAMSUNG_HM121HI_S11JJD0P711641-part5 -> ../../sda5
lrwxrwxrwx 1 root root 10 Jul 17 12:51 ata-SAMSUNG_HM121HI_S11JJD0P711641-part6 -> ../../sda6
lrwxrwxrwx 1 root root 10 Jul 17 12:51 ata-SAMSUNG_HM121HI_S11JJD0P711641-part7 -> ../../sda7
lrwxrwxrwx 1 root root 10 Jul 17 12:51 dm-name-braxen-root -> ../../dm-1
lrwxrwxrwx 1 root root 10 Jul 17 12:51 dm-name-braxen-swap -> ../../dm-2
lrwxrwxrwx 1 root root 10 Jul 17 12:51 dm-name-sda5_crypt -> ../../dm-0
lrwxrwxrwx 1 root root 10 Jul 17 12:51 dm-uuid-CRYPT-LUKS1-78b0a63f081148f78e9a471693e30c8f-sda5_crypt -> ../../dm-0
lrwxrwxrwx 1 root root 10 Jul 17 12:51 dm-uuid-LVM-GMTL2dSegQ3Srdb4rjtipiR3Gdd0Y1VEF98jIUxiX1cGeBLmXoYg9TFvXcT4ODEG -> ../../dm-2
lrwxrwxrwx 1 root root 10 Jul 17 12:51 dm-uuid-LVM-GMTL2dSegQ3Srdb4rjtipiR3Gdd0Y1VEIZbUpH1MFc1ytVL0ELldBCl2N2dtcHZ3 -> ../../dm-1
lrwxrwxrwx 1 root root  9 Jul 17 15:35 md-name-braxen:0 -> ../../md0
lrwxrwxrwx 1 root root  9 Jul 17 15:35 md-uuid-38d7254f:6070327f:d41ae1bb:3d415913 -> ../../md0
lrwxrwxrwx 1 root root  9 Jul 17 15:27 scsi-SATA_SAMSUNG_HM121HIS11JJD0P711641 -> ../../sda
lrwxrwxrwx 1 root root 10 Jul 17 12:51 scsi-SATA_SAMSUNG_HM121HIS11JJD0P711641-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jul 17 12:51 scsi-SATA_SAMSUNG_HM121HIS11JJD0P711641-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Jul 17 12:51 scsi-SATA_SAMSUNG_HM121HIS11JJD0P711641-part5 -> ../../sda5
lrwxrwxrwx 1 root root 10 Jul 17 12:51 scsi-SATA_SAMSUNG_HM121HIS11JJD0P711641-part6 -> ../../sda6
lrwxrwxrwx 1 root root 10 Jul 17 12:51 scsi-SATA_SAMSUNG_HM121HIS11JJD0P711641-part7 -> ../../sda7
lrwxrwxrwx 1 root root  9 Jul 17 15:27 wwn-0x50f0000000711641 -> ../../sda
lrwxrwxrwx 1 root root 10 Jul 17 12:51 wwn-0x50f0000000711641-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jul 17 12:51 wwn-0x50f0000000711641-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Jul 17 12:51 wwn-0x50f0000000711641-part5 -> ../../sda5
lrwxrwxrwx 1 root root 10 Jul 17 12:51 wwn-0x50f0000000711641-part6 -> ../../sda6
lrwxrwxrwx 1 root root 10 Jul 17 12:51 wwn-0x50f0000000711641-part7 -> ../../sda7

/dev/disk/by-label:
total 0
lrwxrwxrwx 1 root root 10 Jul 17 12:51 \x2f -> ../../dm-1
lrwxrwxrwx 1 root root 10 Jul 17 12:51 \x2fboot -> ../../sda6

/dev/disk/by-path:
total 0
lrwxrwxrwx 1 root root  9 Jul 17 12:51 pci-0000:00:1f.1-scsi-0:0:0:0 -> ../../sr0
lrwxrwxrwx 1 root root  9 Jul 17 15:27 pci-0000:00:1f.2-scsi-0:0:0:0 -> ../../sda
lrwxrwxrwx 1 root root 10 Jul 17 12:51 pci-0000:00:1f.2-scsi-0:0:0:0-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jul 17 12:51 pci-0000:00:1f.2-scsi-0:0:0:0-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Jul 17 12:51 pci-0000:00:1f.2-scsi-0:0:0:0-part5 -> ../../sda5
lrwxrwxrwx 1 root root 10 Jul 17 12:51 pci-0000:00:1f.2-scsi-0:0:0:0-part6 -> ../../sda6
lrwxrwxrwx 1 root root 10 Jul 17 12:51 pci-0000:00:1f.2-scsi-0:0:0:0-part7 -> ../../sda7

/dev/disk/by-uuid:
total 0
lrwxrwxrwx 1 root root 10 Jul 17 12:51 03e51aea-e85e-4a7e-af1b-bed00a51fdf5 -> ../../dm-1
lrwxrwxrwx 1 root root 10 Jul 17 12:51 094c07e4-ff9a-4a4f-9513-3cb0ab10e0ca -> ../../sda7
lrwxrwxrwx 1 root root 10 Jul 17 12:51 4537d4aa-df9c-4354-a201-167b1aabac66 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jul 17 12:51 5071213c-4b3b-4be6-bb5e-3c84e21bebd4 -> ../../sda6
lrwxrwxrwx 1 root root 10 Jul 17 12:51 78b0a63f-0811-48f7-8e9a-471693e30c8f -> ../../sda5

/dev/md:
total 0

Auto-generated on Sat, 17 Jul 2010 15:45:12 +0200
by mdadm bugscript 3.1.2-2

-- System Information:
Debian Release: squeeze/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'stable'), (50, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.34-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages mdadm depends on:
ii  debconf                       1.5.33     Debian configuration management sy
ii  libc6                         2.11.2-2   Embedded GNU C Library: Shared lib
ii  lsb-base                      3.2-23.1   Linux Standard Base 3.2 init scrip
ii  makedev                       2.3.1-89   creates device files in /dev
ii  udev                          160-1      /dev/ and hotplug management daemo

Versions of packages mdadm recommends:
ii  masqmail [mail-transport-agen 0.2.21-8   mail transport agent for intermitt
ii  module-init-tools             3.12-1     tools for managing Linux kernel mo

mdadm suggests no packages.

-- debconf information:
  mdadm/autostart: true
* mdadm/initrdstart: all
  mdadm/initrdstart_notinconf: false
  mdadm/initrdstart_msg_errexist:
  mdadm/initrdstart_msg_intro:
  mdadm/initrdstart_msg_errblock:
* mdadm/start_daemon: false
  mdadm/mail_to: root
  mdadm/initrdstart_msg_errmd:
  mdadm/initrdstart_msg_errconf:
* mdadm/autocheck: true

More information about the pkg-mdadm-devel mailing list