On Mon, 1 Apr 2013 23:15:07 -0700 (PDT), Christian Kujau <lists@xxxxxxxxxxxxxxx> wrote:
> Hi,
>
> my machine (PowerBook G4) just crashed and the only thing netconsole was
> able to transmit was:
>
> ------------[ cut here ]------------
> kernel BUG at /usr/local/src/linux-git/fs/ext4/inode.c:1591!
>
> But (unfortunately) nothing more. I have no clear way to reproduce this,
> but I have some kind of a (longish) backstory to this, see below. The
> system is running 3.9-rc4, its .config and dmesg:
>
> http://nerdbynature.de/bits/3.9.0-rc1/config.gz (oldconfig'ed to -rc4)
> http://nerdbynature.de/bits/3.9.0-rc1/dmesg.txt (w/o the calltrace at the end)
>
>
> I was having trouble all day downloading a file via bittorrent to an
> ext4 filesystem. It came always back as corrupted, though I won't be able
> to point out the corruption, as don't know the contents of the source
> file. The ext4 filesystem sits on top of a dm-crypt LUKS device:
>
> /dev/mapper/wdc0 on /mnt/data type ext4 (rw,nosuid,nodev,noexec,relatime,data=ordered)
>
> While looking around as to why the file would be corrupt, the internet
> suggested "bad memory" or "bad disk" or "kernel bugs". I have dismissed
> the first two, as the system is rock-stable otherwise and dmesg has no
> kernel messages suggesting disk or filesystem problems.
Unfortunately it is like a regression which we missed
due to s390x and ppc is not well tested.
>
> The file in question is ~800 MB in size. Not getting any further on a
> solution to my corrupted file, I decided to download a 4.3GB Fedora
> installation image via bittorrent to the same filesystem and that's when
> the machine crashed, leaving only the single BUG message as a hint.
Ohh that is sad. Unfortunately I can't reproduce this on my own
environment. I have power mac pro G5 but w/o graphics card, so i cant
install linux on it. If you know how to do that w/o monitor please let
me know.
So you just do bunch of writes/mmap to fallocated area.
The only guess I have is that some bug in extent status tree
Please run test with a patch which was posted here:
http://marc.info/?l=linux-kernel&m=136455173926544&w=2
This patch enable sanity checks for extent_status tree.
Also please try following patch. It voluntary disable es_lookup functionality.
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index fe3337a..95d27cd 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -689,6 +689,7 @@ int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
trace_ext4_es_lookup_extent_enter(inode, lblk);
es_debug("lookup extent in block %u\n", lblk);
+ return 0;
tree = &EXT4_I(inode)->i_es_tree;
read_lock(&EXT4_I(inode)->i_es_lock);
>
> The system is back now, e2fsck-1.42.5 came back with no errors.
>
> Thanks for reading,
> Christian.
>
> PS: somewhat off-topic, but: is there a way to have BUG_ON print only
> fs/ext4/inode.c:1591! instead of the full pathname? Is there are
> config option for this?
> --
> BOFH excuse #339:
>
> manager in the cable duct
