Re: XFS Mount Hangs the Partition (on latest kernel + many old 2.6.x ones)

[Nathan Scott <nathans@sgi.com>]

On Wed, Dec 07, 2005 at 01:57:38PM +0200, Shlomi Fish wrote:
> Hi all!

Hi there,

> (Please CC me on replies)
> 
> I encountered a problem with the Linux kernel handling of XFS, in which
> attempting to mount a certain XFS partition (but not a different one on the
> same hard-disk) caused the mount process to hang, and all other XFS-aware
> apps (like "xfs_check" or "xfs_repair") to hang too. However, running 
> xfs_check
> or xfs_repair before the first mount (after a reboot) worked, and eventually
> resolved this problem.
> 
> I blogged about it (relatively incoherently) here:
> 
> http://www.livejournal.com/~shlomif/7182.html?mode=reply
> http://www.livejournal.com/~shlomif/7547.html?mode=reply

Unfortunately there's not much information here in your mail or
there that would help us to analyse this further.  If you see this
behaviour again could you:
- get sysrq-t information for all hung processes, esp. mount;
- send xfs_info output for the filesystem in question;
- dump the log (xfs_logprint -C) and send it to us.

> It all happened after I detected some problems on my Mandriva 2006 system 
> (that was using kernel 2.4.15-rc2 from Linus), and then rebooted twice, 
> thinking something went wrong. Then a loadlin-booted kernel was unable to 
> load the kernel. 
> 
> Knoppix ran fine, but it also hang up on attempting to mount the XFS 
> partition. It used a much older kernel. I then tried to boot Kubuntu (which
> was on another XFS partition on the same disk) and it booted fine. Still, it
> was unable to mount the partition. (It too had an older kernel). 
> 
> After I compiled a 2.6.14.3 kernel, and booted Kubuntu with it, it again
> could not mount the XFS partition, and after doing that xfs_check and 
> xfs_repair both hanged up as well. After a reboot, I tried running xfs_check

This was probably caused by the block device being held open
exclusively by the stuck mount process.

> right away on that partition and it worked. So I ran xfs_repair, and after it
> finished, tried to mount the partition it worked. Then Mandriva booted fine.
> 
> I did not had any problems since then (I have an uptime of 11 days now using
> kernel 2.6.14.3), and so it doesn't seem like a hard disk problem. Something
> using kernel 2.6.15-rc2 caused the XFS partition to become defected, and 
> worse - something in all the kernels starting from that of the first official
> Kubuntu release, (or the Knoppix I had), caused an attempt to mount the 
> Mandriva partition to hang the process, and subsequent accesses to the 
> partition by xfs_check and xfs_repair to fail as well.
> 
> I can no longer reproduce the problem, but it might be worth going over the 
> code. If it helps I can privately send a dump of the first 131,072,000 bytes
> of the XFS partition to someone trustworthy. 

Thats unlikely to help now - repair will have wiped your log clean,
so all evidence of the problem will be gone.

cheers.

-- 
Nathan