* Re: mdadm-3.2.5: segfault in "--grow --continue"
2012-07-10 13:02 ` NeilBrown
@ 2012-07-10 16:51 ` Sebastian Hegler
2012-07-11 2:26 ` NeilBrown
0 siblings, 1 reply; 6+ messages in thread
From: Sebastian Hegler @ 2012-07-10 16:51 UTC (permalink / raw)
To: NeilBrown; +Cc: linux-raid, 681056
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Hi!
Am 10.07.2012 um 15:02 schrieb NeilBrown:
> On Tue, 10 Jul 2012 12:46:19 +0200 Sebastian Hegler <sebastian.hegler@tu-dresden.de> wrote:
>> I had to shut down a server with a raid grow operation (cleanly). After some hassles I got the array assembled again (manually), but it would not continue to grow. When trying
>>
>> mdadm --grow --continue /dev/md127
>>
>> (as per the manpage) I receive a segfault. Compiling from source, and using gdb, I see:
>>
>> root@kuiper:~/mdadm-3.2.5# gdb ./mdadm
>> [SNIP]
>> Reading symbols from /root/mdadm-3.2.5/mdadm...done.
>> (gdb) set args --grow --continue /dev/md127
>> (gdb) run
>> Starting program: /root/mdadm-3.2.5/mdadm --grow --continue /dev/md127
>>
>> Program received signal SIGSEGV, Segmentation fault.
>> Grow_continue_command (devname=0x7fffffffe8cc "/dev/md127", fd=7, backup_file=0x0, verbose=0) at Grow.c:4118
>> 4118 if (verify_reshape_position(content,
>> (gdb) bt
>> #0 Grow_continue_command (devname=0x7fffffffe8cc "/dev/md127", fd=7, backup_file=0x0, verbose=0) at Grow.c:4118
>> #1 0x0000000000407ac2 in main (argc=4, argv=0x7fffffffe678) at mdadm.c:1701
>>
>>
>>
>> The same bug is present in the git repository, but another location:
>>
>> root@kuiper:~/mdadm.git# gdb ./mdadm
>> [SNIP]
>> Reading symbols from /root/mdadm.git/mdadm...done.
>> (gdb) set args --grow --continue /dev/md127
>> (gdb) run
>> Starting program: /root/mdadm.git/mdadm --grow --continue /dev/md127
>>
>> Program received signal SIGSEGV, Segmentation fault.
>> Grow_continue_command (devname=0x7fffffffe8d0 "/dev/md127", fd=7, backup_file=0x0, verbose=0) at Grow.c:4086
>> 4086 if (verify_reshape_position(content,
>> (gdb) bt
>> #0 Grow_continue_command (devname=0x7fffffffe8d0 "/dev/md127", fd=7, backup_file=0x0, verbose=0) at Grow.c:4086
>> #1 0x0000000000406c39 in main (argc=4, argv=0x7fffffffe678) at mdadm.c:1447
>>
>>
>> I also filed a bug against Debian's BTS, but I did not receive a bug number yet. In the meantime, I'd be very happy about any information on how to get my RAID array back into growing. I'm not on the list, please CC me.
>
> --grow --continue should only be needed if the array was assembled with --freeze-reshape (I think).
>
> Normally, the reshape should continue automatically.
Well, it did not.
> cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md127 : active raid6 sdi[14] sdh[22] sdt[11] sdp[16] sdq[13] sdo[17] sdn[18] sdu[12] sdm[19] sdl[20] sdk[21] sdj[15]
17581629312 blocks super 1.2 level 6, 128k chunk, algorithm 2 [12/12] [UUUUUUUUUUUU]
> mdadm -E ....
root@kuiper:~# for i in /sys/block/md127/md/dev-sd* ; do mdadm -E /`basename $i |tr - / ` ; done
/dev/sdh:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : active
Device UUID : f281deb2:b5de8070:487c1900:0078e6e1
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:45 2012
Checksum : 16d3efce - correct
Events : 6245853
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 11
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdi:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : active
Device UUID : b67b1847:cb68ac69:7ab0b4ee:894a268b
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:45 2012
Checksum : 3c147a5b - correct
Events : 6245853
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 0
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdj:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 5c4e03cc:e2fe014e:bd3d17a9:517d34f5
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : c9c5a324 - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 1
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdk:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : e276dc2b:048e6135:2364e8d0:00566eed
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : 310959e7 - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 2
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdl:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 547956df:6be81839:89424cbc:664bc6d6
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : bcf68a8b - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 3
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdm:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 72a0a33b:faa5ecd4:7b543389:f49798a2
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : 4dd0cdb7 - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 4
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdn:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 11c4c3ac:ac1be81a:d4750037:45a85a60
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : 707b98b0 - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 6
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdo:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 76692433:04aab129:7f46b4f6:d2d93ffd
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : 623ecea5 - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 7
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdp:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : f62ba0d8:17345ece:55a5d1bf:39540cc5
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : 3d50f475 - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 9
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdq:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : a4091eff:68556278:3a22b428:aa59ea46
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : f89375c5 - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 8
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdt:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : f8425467:c7533842:df4c4da6:424e107f
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : e05eccb3 - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 10
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
/dev/sdu:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : 42683d6d:6479d415:492ede77:6fe9437b
Name : kuiper:scratch2G (local to host kuiper)
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Raid Devices : 12
Avail Dev Size : 3907028736 (1863.02 GiB 2000.40 GB)
Array Size : 19535143680 (18630.17 GiB 20003.99 GB)
Data Offset : 432 sectors
Super Offset : 8 sectors
State : clean
Device UUID : acde8544:51d21dcd:e6b6827e:c258f274
Reshape pos'n : 6220766720 (5932.59 GiB 6370.07 GB)
Delta Devices : 1 (11->12)
Update Time : Tue Jul 10 16:10:46 2012
Checksum : 168d5b7a - correct
Events : 6245852
Layout : left-symmetric
Chunk Size : 128K
Device Role : Active device 5
Array State : AAAAAAAAAAAA ('A' == active, '.' == missing)
> mdadm -D ...
root@kuiper:~# mdadm -D /dev/md127
/dev/md127:
Version : 1.2
Creation Time : Fri Apr 16 12:26:18 2010
Raid Level : raid6
Array Size : 17581629312 (16767.15 GiB 18003.59 GB)
Used Dev Size : 1953514368 (1863.02 GiB 2000.40 GB)
Raid Devices : 12
Total Devices : 12
Persistence : Superblock is persistent
Update Time : Tue Jul 10 16:11:23 2012
State : clean
Active Devices : 12
Working Devices : 12
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 128K
Delta Devices : 1, (11->12)
Name : kuiper:scratch2G (local to host kuiper)
UUID : 42683d6d:6479d415:492ede77:6fe9437b
Events : 6245852
Number Major Minor RaidDevice State
14 8 128 0 active sync /dev/sdi
15 8 144 1 active sync /dev/sdj
21 8 160 2 active sync /dev/sdk
20 8 176 3 active sync /dev/sdl
19 8 192 4 active sync /dev/sdm
12 65 64 5 active sync /dev/sdu
18 8 208 6 active sync /dev/sdn
17 8 224 7 active sync /dev/sdo
13 65 0 8 active sync /dev/sdq
16 8 240 9 active sync /dev/sdp
11 65 48 10 active sync /dev/sdt
22 8 112 11 active sync /dev/sdh
> would be helpful, maybe together with kernel logs if there are any.
Please see the attached files. I truncated the file up until the first segfault of mdadm. Short wrapup of the contents:
* Bad interaction: "mpt-sas ioc1" is too slow for md. md is assembling RAID arrays from the disks it sees, creating some MD devices, one partially broken and recovering where there is no need (if md had waited), and two incomplete arrays actually belonging to one array (timestamps: 35.655213, 34.528229). Some disks are also completely missing thanks to failed slots in the enclosure.
* I then removed all drives belonging to the array I interrupted in the Grow procedure (via "/sys/block/sd*/delete"), re-inserted them into the enclosure, and re-assembled the RAID array manually. Finish is at "1397.498460": "md/raid:md127: reshape will continue"
* At "1565.278839" The RAID array is in "auto-read-only" mode. I mount the FS, wondering about not seeing the enclosure LEDs blink. After checking "/proc/mdstat", I see that everything is quiet, although I expected a progress bar.
* At "2612.464768" (fourth-to-last line) mdadm segfaults with the command "mdadm --grow --continue /dev/md127"
After yet another reboot, and careful manual re-assembly of the RAID array in question, everything works fine. Grow operation continued after mounting the file system.
The issue was assigned bug number 681056 in the Debian BTS in the meantime: CCing the BTS.
Yours,
Sebastian
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