Re: [patch 1/3] fix illogical behavior in balance_dirty_pages()

Kris Corwin
2007-04-03T18:52:00Z

I think I'm seeing the same VM behavior with NFS/ext3 that was described
with fuse.

I have a shared storage unit with 2 servers. The local filesystem is
ext3 and I'm failing
the ext3 mounting and NFS serving from one node to another. I'm running
I/O on the NFS
mount point to the active server. If I failover to the server that is
also executing the I/O,
I can hang the machine. Looking at the stack traces, the NFS writes are
stuck in
balance_dirty_pages(). NFS start up is causing rpc.mountd to write to
the local
ext3 filesystem, but it gets blocked in balance_dirty_pages() too.
Deadlock. Without
the NFS server successfully started, the kernel can't write the dirty pages.

I'm running a 2.6.9-42 RH kernel. Early in my debugging, I had tried
several kernel
versions. All 2.6 kernels saw this behavior and the 2.4 kernel I tried
did not.

Kris Corwin