On Tue, Jul 02, 2013 at 11:22:00AM +0200, Michal Hocko wrote:
> On Mon 01-07-13 18:10:56, Dave Chinner wrote:
> > On Mon, Jul 01, 2013 at 09:50:05AM +0200, Michal Hocko wrote:
> > > On Mon 01-07-13 11:25:58, Dave Chinner wrote:
> > That is the recycle stat, which indicates we've found an inode being
> > reclaimed. When it's found an inode that have been evicted, but not
> > yet reclaimed at the XFS level, that stat will increase. If the
> > inode is still valid at the VFS level, and igrab() fails, then we'll
> > get EAGAIN without that stat being increased. So, igrab() is
> > failing, and that means I_FREEING|I_WILL_FREE are set.
> >
> > So, it looks to be the same case as the ext4 hang, and it's likely
> > that we have some dangling inode dispose list somewhere. So, here's
> > the fun part. Use tracing to grab the inode number that is stuck
> > (tracepoint xfs::xfs_iget_skip),
>
> $ cat /sys/kernel/debug/tracing/trace_pipe > demon.trace.log &
> $ pid=$!
> $ sleep 10s ; kill $pid
> $ awk '{print $1, $9}' demon.trace.log | sort -u
> cc1-7561 0xf78d4f
> cc1-9100 0x80b2a35
.....
>
> > and the dispose list that it is on should be the on the
> > inode->i_lru_list.
>
> crash> struct inode.i_lru ffff88000c09e2f8
> i_lru = {
> next = 0xffff88000c09e3e8,
> prev = 0xffff88000c09e3e8
> }
Hmmm, that's empty.
> crash> struct inode.i_flags ffff88000c09e2f8
> i_flags = 4096
I asked for the wrong field, I wanted i_state, but seeing as you:
> The full xfs_inode dump is attached.
Dumped the whole inode, I got it from below :)
> i_state = 32,
so, i_state = I_FREEING.
IOWs, we've got an inode marked I_FREEING that isn't on a dispose
list but hasn't passed through evict() correctly.
> crash> struct xfs_inode ffff88000c09e1c0
> struct xfs_inode {
.....
> i_flags = 0,
XFS doesn't see the inode as reclaimable yet, either.
Ok, so it's been leaked from a dispose list somehow. Thanks for the
info, Michal, it's time to go look at the code....
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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