Re: [PATCH v2 1/3] xfs: add scan owner field to xfs_eofblocks

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Fri, May 23, 2014 at 07:52:28AM -0400, Brian Foster wrote:
> The scan owner field represents an optional inode number that is
> responsible for the current scan. The purpose is to identify that an
> inode is under iolock and as such, the iolock shouldn't be attempted
> when trimming eofblocks. This is an internal only field.

xfs_free_eofblocks already does a trylock, and without that calling it
from one iolock holding process to another would be a deadlock waiting
to happen.

I have to say I'm still not very easy with iolock nesting, even if it's
a trylock.