Re: [PATCH v2 10/9] xfs: add debug knob to slow down writeback for fun

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Nov 29, 2022 at 12:34:53PM +1100, Dave Chinner wrote:
> On Mon, Nov 28, 2022 at 05:21:18PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@xxxxxxxxxx>
> > 
> > Add a new error injection knob so that we can arbitrarily slow down
> > writeback to test for race conditions and aberrant reclaim behavior if
> > the writeback mechanisms are slow to issue writeback.  This will enable
> > functional testing for the ifork sequence counters introduced in commit
> > 745b3f76d1c8 ("xfs: maintain a sequence count for inode fork
> > manipulations").
> > 
> > Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> > ---
> > v2: this time with tracepoints
> > ---
> .....
> 
> > @@ -267,6 +270,14 @@ xfs_errortag_valid(
> >  	return true;
> >  }
> >  
> > +bool
> > +xfs_errortag_enabled(
> > +	struct xfs_mount	*mp,
> > +	unsigned int		tag)
> > +{
> > +	return mp->m_errortag && mp->m_errortag[tag] != 0;
> > +}
> 
> Perhaps consider using the new xfs_errortag_valid() helper? i.e.
> 
> {
> 	if (!mp->errortag)
> 		return false;
> 	if (!xfs_errortag_valid(tag))
> 		return false;
> 	return mp->m_errortag[tag] != 0;

Fixed.

> }
> 
> > +
> >  bool
> >  xfs_errortag_test(
> >  	struct xfs_mount	*mp,
> > diff --git a/fs/xfs/xfs_error.h b/fs/xfs/xfs_error.h
> > index 5191e9145e55..936d0c52d6af 100644
> > --- a/fs/xfs/xfs_error.h
> > +++ b/fs/xfs/xfs_error.h
> > @@ -45,6 +45,17 @@ extern bool xfs_errortag_test(struct xfs_mount *mp, const char *expression,
> >  		const char *file, int line, unsigned int error_tag);
> >  #define XFS_TEST_ERROR(expr, mp, tag)		\
> >  	((expr) || xfs_errortag_test((mp), #expr, __FILE__, __LINE__, (tag)))
> > +bool xfs_errortag_enabled(struct xfs_mount *mp, unsigned int tag);
> > +#define XFS_ERRORTAG_DELAY(mp, tag)		\
> > +	do { \
> > +		if (!xfs_errortag_enabled((mp), (tag))) \
> > +			break; \
> > +		xfs_warn_ratelimited((mp), \
> > +"Injecting %ums delay at file %s, line %d, on filesystem \"%s\"", \
> > +				(mp)->m_errortag[(tag)], __FILE__, __LINE__, \
> > +				(mp)->m_super->s_id); \
> > +		mdelay((mp)->m_errortag[(tag)]); \
> > +	} while (0)
> 
> Putting a might_sleep() in this macro might be a good idea - that
> will catch delays being added inside spin lock contexts...

Done.  Thanks for the review!

--D

> Other than that, it looks fine.
> 
> Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
> 
> -- 
> Dave Chinner
> david@xxxxxxxxxxxxx



[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [NTFS 3]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [NTFS 3]     [Samba]     [Device Mapper]     [CEPH Development]

  Powered by Linux