Re: xfs: Uninitialized memory read at xlog_write

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Wed, Sep 20, 2017 at 10:46:39AM +1000, Dave Chinner wrote:
> On Mon, Sep 18, 2017 at 11:21:21AM -0700, Darrick J. Wong wrote:
> > On Fri, Sep 15, 2017 at 08:44:31AM +1000, Dave Chinner wrote:
> > > xfs: Don't log uninitialised fields in inode structures
> > > 
> > > From: Dave Chinner <dchinner@redhat.com>
> > > 
> > > Prevent kmemcheck from throwing warnings about reading uninitialised
> > > memory when formatting inodes into the incore log buffer. There are
> > > several issues here - we don't always log all the fields in the
> > > inode log format item, and we never log the inode the
> > > di_next_unlinked field.
> > > 
> > > In the case of the inode log format item, this is aused b cerbated
> > 
> > "is aused b cerbated" ?
> 
> vi fail when replacing the word "used" with "exacerbated". :)
> 
> > > by the old xfs_inode_log_format structure padding issue. Hence make
> > > the padded, 64 bit aligned version of the structure the one we always
> > > use for formatting the log and get rid of the 64 bit variant. This
> > > means we'll always log the 64-bit version and so recovery only needs
> > > to convert from the unpadded 32 bit version from older 32 bit
> > > kernels.
> > 
> > And those old 32-bit kernels can read the xfs_inode_log_format{,_64}
> > structures, right?
> 
> Yes. With the in-memory format now being the same as the old
> xfs_inode_log_format_64 structure in the log, we only need a
> conversion from "32 bit in log to 64 bit in memory" on all
> platforms.

Ok, that's what I thought.  Will await a positive test result + proper
patch submission. :)

--D

> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@fromorbit.com
> --
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