Re: [PATCH 09/19] XFS: ensure xfs_file_*_read cannot deadlock in memory allocation.

Dave Chinner
2014-04-16T06:31:33Z

On Wed, Apr 16, 2014 at 04:04:59PM +1000, Dave Chinner wrote:
> On Wed, Apr 16, 2014 at 02:03:36PM +1000, NeilBrown wrote:
> > xfs_file_*_read holds an inode lock while calling a generic 'read'
> > function. These functions perform read-ahead and are quite likely to
> > allocate memory.
>
> Yes, that's what reading data from disk requires.
>
> > So set PF_FSTRANS to ensure they avoid __GFP_FS and so don't recurse
> > into a filesystem to free memory.
>
> We already have that protection via the

Oops, stray paste. Ignore that comment.

-Dave.
--
Dave Chinner
david@fromorbit.com