linux-btrfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mark Zealey <mark@markandruth.co.uk>
To: linux-btrfs@vger.kernel.org
Subject: Filesystem hang on kernel 4.2.0 with copy reflink
Date: Mon, 4 Jan 2016 10:35:43 +0200	[thread overview]
Message-ID: <568A2EDF.6090909@markandruth.co.uk> (raw)

Hi there, I've run into a very strange hang with btrfs. I was trying to 
restore a directory (postgres database) from a readonly snapshot. To do 
this i used the command `cp -ar --reflink=always`. This worked fine for 
100s of files, however when it got to a particular file 16 kworker 
threads (I have 8 processors in this system) got marked as being in D 
state (with 0 cpu usage or disk usage) and I could not access the btrfs 
file system any more. I can't see any kernel message or OOPS. Can you 
please let me know what additional debug information I can provide to 
help track this issue down in the kernel?

System is latest ubuntu 14.04 LTS with a backported wily kernel (package 
linux-image-4.2.0-22-generic):

4.2.0-22-generic #27~14.04.1-Ubuntu SMP Fri Dec 18 10:57:53 UTC 2015 
x86_64 x86_64 x86_64 GNU/Linux

Thanks

Mark

             reply	other threads:[~2016-01-04  8:52 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-04  8:35 Mark Zealey [this message]
2016-01-04 10:41 ` Filesystem hang on kernel 4.2.0 with copy reflink Jack Wang
2016-01-04 12:11   ` Mark Zealey
2016-01-09  9:28     ` Duncan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=568A2EDF.6090909@markandruth.co.uk \
    --to=mark@markandruth.co.uk \
    --cc=linux-btrfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).