Comment # 6 on bug 1049599 from Jiri Slaby

Right, the crash is fixed,
opensuse-Staging:L-Staging2-DVD-x86_64-Build139.1-RAID10@64bit is green now.

The warning still remains and is as follows:

md/raid10:md0: not clean -- starting background reconstruction
md/raid10:md0: active with 4 out of 4 devices
md0: detected capacity change from 0 to 16779182080
md: resync of RAID array md0
md/raid1:md1: not clean -- starting background reconstruction
md/raid1:md1: active with 4 out of 4 mirrors
md1: detected capacity change from 0 to 311361536
md: delaying resync of md1 until md0 has finished (they share one or more
physical units)
md2: detected capacity change from 0 to 427687936
Btrfs loaded, crc32c=crc32c-generic, assert=on
BTRFS: device fsid 47d14b73-f12e-490c-b139-63b60bb41655 devid 1 transid 5
/dev/md0
BTRFS info (device md0): disk space caching is enabled
BTRFS info (device md0): has skinny extents
BTRFS info (device md0): flagging fs with big metadata feature
BTRFS info (device md0): creating UUID tree
BTRFS info (device md0): setting 2 feature flag
BTRFS info (device md0): disk space caching is enabled
BTRFS info (device md0): has skinny extents
BTRFS info (device md0): disk space caching is enabled
BTRFS info (device md0): has skinny extents
Adding 417660k swap on /dev/md2.  Priority:-1 extents:1 across:417660k FS
BTRFS info (device md0): disk space caching is enabled
BTRFS info (device md0): has skinny extents
EXT4-fs (md1): mounted filesystem with ordered data mode. Opts: acl,user_xattr
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5537 at ../drivers/md/md.h:779
raid10_sync_request+0x1578/0x1ab0 [raid10]
Modules linked in: btrfs dm_multipath dm_mod raid10 raid456 async_raid6_recov
async_memcpy libcrc32c async_pq async_xor xor async_tx raid6_pq raid1 raid0
md_mod parport_pc parport nls_utf8 isofs usb_storage 8021q garp mrp stp llc
arc4 fan thermal nfs lockd grace fscache nls_iso8859_1 nls_cp437 af_packet sg
st iscsi_ibft iscsi_boot_sysfs sunrpc sr_mod cdrom hid_generic usbhid cirrus
ttm ehci_pci drm_kms_helper ehci_hcd ata_generic usbcore drm floppy ata_piix
qemu_fw_cfg syscopyarea sysfillrect sysimgblt button fb_sys_fops virtio_net
virtio_scsi virtio_blk i2c_piix4 scsi_dh_rdac scsi_dh_emc scsi_dh_alua edd
squashfs loop [last unloaded: ppa]
CPU: 0 PID: 5537 Comm: md0_resync Not tainted 4.12.2-5-default #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
task: ffff8f4d8480c1c0 task.stack: ffffb7e440d18000
RIP: 0010:raid10_sync_request+0x1578/0x1ab0 [raid10]
RSP: 0018:ffffb7e440d1bc38 EFLAGS: 00010212
RAX: 0000000000000010 RBX: ffff8f4db643d600 RCX: 0000000000000011
RDX: ffff8f4d884ae490 RSI: ffff8f4d8319e900 RDI: ffff8f4d8b89a050
RBP: 0000000000001000 R08: 0000000000000002 R09: ffff8f4db6446e00
R10: ffffe2aa40032020 R11: 00000000008a9500 R12: 0000000000000008
R13: 0000000001152a08 R14: 0000000000000000 R15: ffff8f4db643d600
FS:  0000000000000000(0000) GS:ffff8f4dba200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3817800000 CR3: 000000001b71f000 CR4: 00000000000006f0
Call Trace:
 ? call_timer_fn+0x150/0x150
 ? is_mddev_idle+0xfa/0x10c [md_mod]
 md_do_sync+0x8a4/0xec0 [md_mod]
 ? finish_wait+0x80/0x80
 ? find_pers+0x70/0x70 [md_mod]
 ? md_thread+0x109/0x140 [md_mod]
 md_thread+0x109/0x140 [md_mod]
 kthread+0x118/0x130
 ? kthread_create_on_node+0x40/0x40
 ret_from_fork+0x25/0x30
Code: 48 a0 6e 7c c0 75 d9 48 8b 47 08 48 8b 40 60 48 8b 80 80 00 00 00 3e 01
a8 00 04 00 00 c7 47 10 00 00 00 00 e8 ea 64 bc e4 eb b5 <0f> ff 31 f6 e9 71 ff
ff ff 41 bc 08 00 00 00 bd 00 10 00 00 e9
---[ end trace 1a6bcd14bc423205 ]---
md: md0: resync done.
md: resync of RAID array md1
md: md1: resync done.