Re: 4.7.0-rc7 ext4 error in dx_probe

[TÃrÃk Edwin]

Hi,


I have just encountered a similar problem after I've recently upgraded to 4.7.0:
[Wed Aug  3 11:08:57 2016] EXT4-fs error (device dm-1): dx_probe:740: inode #13295: comm python: Directory index failed checksum
[Wed Aug  3 11:08:57 2016] Aborting journal on device dm-1-8.
[Wed Aug  3 11:08:57 2016] EXT4-fs (dm-1): Remounting filesystem read-only
[Wed Aug  3 11:08:57 2016] EXT4-fs error (device dm-1): ext4_journal_check_start:56: Detected aborted journal

I've rebooted in single-user mode, fsck fixed the filesystem, and rebooted, filesystem is rw again now.

inode #13295 seems to be this and I can list it now:
stat /usr/lib64/python3.4/site-packages
  File: '/usr/lib64/python3.4/site-packages'
  Size: 12288     	Blocks: 24         IO Block: 4096   directory
Device: fd01h/64769d	Inode: 13295       Links: 180
Access: (0755/drwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2016-05-09 11:29:44.056661988 +0300
Modify: 2016-08-01 00:34:24.029779875 +0300
Change: 2016-08-01 00:34:24.029779875 +0300
 Birth: -

The filesystem was /, I only noticed it was readonly after several hours when I tried to install something:
/dev/mapper/vg--ssd-root on / type ext4 (rw,noatime,errors=remount-ro,data=ordered)

$ uname -a
Linux bolt 4.7.0-gentoo-rr #1 SMP Thu Jul 28 11:28:56 EEST 2016 x86_64 AMD FX(tm)-8350 Eight-Core Processor AuthenticAMD GNU/Linux

FWIW I've been using ext4 for years and this is the first time I see this message.
Prior to 4.7 I was on 4.6.1 -> 4.6.2 -> 4.6.3 -> 4.6.4.

The kernel is from gentoo-sources + a patch for enabling AMD LWP (I had that patch since 4.6.3 and its not related to I/O).

If I see this message again what should I do to obtain more information to trace down the root cause?

Best regards,
-- 
Edwin TÃrÃk | Co-founder and Lead Developer

Skylable open-source object storage: reliable, fast, secure
http://www.skylable.com