[OpenAFS-devel] Re: Problems on 8-way Itanium2 system

[Kris Van Hees]

On Wed, Mar 02, 2005 at 11:12:51PM +0100, Martin MOKREJ? wrote:
> Kris Van Hees wrote:
> >Pending a patch I am still working on, you *may* run into an issue with an
> >ext3 cache.  Basically, if you are writing a file to an AFS volume, and 
> >that
> >file is larger than the cache, and the cache is its own ext3 partition, it
> >is possible that a race condition pops up between the journal commit 
> >process
> >and the AFS client.  The journal commit process can at times be too slow in
> >writing truncate commit records to disk, which causes cache blocks to be
> >considered available by the AFS client while the ext3 fs will not be able 
> >to
> >allocate those blocks yet.
> >
> >Result: partition full error from the fs layer, and thus the write aborts.
> >
> >Patch is being worked on (actually, I have a patch - I just need to test it
> >more to see what (if any) the performance impact is).
> 
> Do you think this could be the case for bug #17740, while on ext2?

The ext2 filesystem should not experience this problem because it is not a
journaled filesystem.  Also, note that in the scenario I described, the write
operation would have logged a message to the console (also showing up in dmesg
output):

afs: failed to store file (partition full)

	Kris

	Kris