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* [PATCH v2] xfs: Fix rounding in xfs_alloc_fix_len()
@ 2014-06-04 16:53 Jan Kara
  2014-06-04 18:44 ` Brian Foster
  0 siblings, 1 reply; 5+ messages in thread
From: Jan Kara @ 2014-06-04 16:53 UTC (permalink / raw)
  To: xfs; +Cc: Brian Foster, Jan Kara

Rounding in xfs_alloc_fix_len() is wrong. As the comment states, the
result should be a number of a form (k*prod+mod) however due to sign
mistake the result is different. As a result allocations on raid arrays
could be misaligned in some cases.

This also seems to fix occasional assertion failure:
	XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0)
in xfs_alloc_ag_vextent_size().

Also add an assertion that the result of xfs_alloc_fix_len() is of
expected form.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/xfs/xfs_alloc.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index c1cf6a336a72..1351a24d3cdc 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -257,16 +257,14 @@ xfs_alloc_fix_len(
 	k = rlen % args->prod;
 	if (k == args->mod)
 		return;
-	if (k > args->mod) {
-		if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
-			return;
-	} else {
-		if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
-		    (int)args->minlen)
-			return;
-	}
-	ASSERT(rlen >= args->minlen);
-	ASSERT(rlen <= args->maxlen);
+	if (k > args->mod)
+		rlen = rlen - (k - args->mod);
+	else
+		rlen = rlen - args->prod + (args->mod - k);
+	if ((int)rlen < (int)args->minlen)
+		return;
+	ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
+	ASSERT(rlen % args->prod == args->mod);
 	args->len = rlen;
 }
 
-- 
1.8.1.4

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH v2] xfs: Fix rounding in xfs_alloc_fix_len()
  2014-06-04 16:53 [PATCH v2] xfs: Fix rounding in xfs_alloc_fix_len() Jan Kara
@ 2014-06-04 18:44 ` Brian Foster
  2014-06-13 15:02   ` Jan Kara
  0 siblings, 1 reply; 5+ messages in thread
From: Brian Foster @ 2014-06-04 18:44 UTC (permalink / raw)
  To: Jan Kara; +Cc: xfs

On Wed, Jun 04, 2014 at 06:53:53PM +0200, Jan Kara wrote:
> Rounding in xfs_alloc_fix_len() is wrong. As the comment states, the
> result should be a number of a form (k*prod+mod) however due to sign
> mistake the result is different. As a result allocations on raid arrays
> could be misaligned in some cases.
> 
> This also seems to fix occasional assertion failure:
> 	XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0)
> in xfs_alloc_ag_vextent_size().
> 
> Also add an assertion that the result of xfs_alloc_fix_len() is of
> expected form.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---

Looks good to me. Thanks Jan.

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/xfs_alloc.c | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
> index c1cf6a336a72..1351a24d3cdc 100644
> --- a/fs/xfs/xfs_alloc.c
> +++ b/fs/xfs/xfs_alloc.c
> @@ -257,16 +257,14 @@ xfs_alloc_fix_len(
>  	k = rlen % args->prod;
>  	if (k == args->mod)
>  		return;
> -	if (k > args->mod) {
> -		if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
> -			return;
> -	} else {
> -		if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
> -		    (int)args->minlen)
> -			return;
> -	}
> -	ASSERT(rlen >= args->minlen);
> -	ASSERT(rlen <= args->maxlen);
> +	if (k > args->mod)
> +		rlen = rlen - (k - args->mod);
> +	else
> +		rlen = rlen - args->prod + (args->mod - k);
> +	if ((int)rlen < (int)args->minlen)
> +		return;
> +	ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
> +	ASSERT(rlen % args->prod == args->mod);
>  	args->len = rlen;
>  }
>  
> -- 
> 1.8.1.4
> 
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH v2] xfs: Fix rounding in xfs_alloc_fix_len()
  2014-06-04 18:44 ` Brian Foster
@ 2014-06-13 15:02   ` Jan Kara
  2014-06-13 23:56     ` Dave Chinner
  0 siblings, 1 reply; 5+ messages in thread
From: Jan Kara @ 2014-06-13 15:02 UTC (permalink / raw)
  To: Brian Foster; +Cc: dchinner, Jan Kara, xfs

On Wed 04-06-14 14:44:40, Brian Foster wrote:
> On Wed, Jun 04, 2014 at 06:53:53PM +0200, Jan Kara wrote:
> > Rounding in xfs_alloc_fix_len() is wrong. As the comment states, the
> > result should be a number of a form (k*prod+mod) however due to sign
> > mistake the result is different. As a result allocations on raid arrays
> > could be misaligned in some cases.
> > 
> > This also seems to fix occasional assertion failure:
> > 	XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0)
> > in xfs_alloc_ag_vextent_size().
> > 
> > Also add an assertion that the result of xfs_alloc_fix_len() is of
> > expected form.
> > 
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
> 
> Looks good to me. Thanks Jan.
> 
> Reviewed-by: Brian Foster <bfoster@redhat.com>
  Ping Dave? Are you going to pick up this patch?

							Honza
 
> >  fs/xfs/xfs_alloc.c | 18 ++++++++----------
> >  1 file changed, 8 insertions(+), 10 deletions(-)
> > 
> > diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
> > index c1cf6a336a72..1351a24d3cdc 100644
> > --- a/fs/xfs/xfs_alloc.c
> > +++ b/fs/xfs/xfs_alloc.c
> > @@ -257,16 +257,14 @@ xfs_alloc_fix_len(
> >  	k = rlen % args->prod;
> >  	if (k == args->mod)
> >  		return;
> > -	if (k > args->mod) {
> > -		if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
> > -			return;
> > -	} else {
> > -		if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
> > -		    (int)args->minlen)
> > -			return;
> > -	}
> > -	ASSERT(rlen >= args->minlen);
> > -	ASSERT(rlen <= args->maxlen);
> > +	if (k > args->mod)
> > +		rlen = rlen - (k - args->mod);
> > +	else
> > +		rlen = rlen - args->prod + (args->mod - k);
> > +	if ((int)rlen < (int)args->minlen)
> > +		return;
> > +	ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
> > +	ASSERT(rlen % args->prod == args->mod);
> >  	args->len = rlen;
> >  }
> >  
> > -- 
> > 1.8.1.4
> > 
> > _______________________________________________
> > xfs mailing list
> > xfs@oss.sgi.com
> > http://oss.sgi.com/mailman/listinfo/xfs
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH v2] xfs: Fix rounding in xfs_alloc_fix_len()
  2014-06-13 15:02   ` Jan Kara
@ 2014-06-13 23:56     ` Dave Chinner
  2014-06-16  9:00       ` Jan Kara
  0 siblings, 1 reply; 5+ messages in thread
From: Dave Chinner @ 2014-06-13 23:56 UTC (permalink / raw)
  To: Jan Kara; +Cc: Brian Foster, xfs, dchinner

On Fri, Jun 13, 2014 at 05:02:07PM +0200, Jan Kara wrote:
> On Wed 04-06-14 14:44:40, Brian Foster wrote:
> > On Wed, Jun 04, 2014 at 06:53:53PM +0200, Jan Kara wrote:
> > > Rounding in xfs_alloc_fix_len() is wrong. As the comment states, the
> > > result should be a number of a form (k*prod+mod) however due to sign
> > > mistake the result is different. As a result allocations on raid arrays
> > > could be misaligned in some cases.
> > > 
> > > This also seems to fix occasional assertion failure:
> > > 	XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0)
> > > in xfs_alloc_ag_vextent_size().
> > > 
> > > Also add an assertion that the result of xfs_alloc_fix_len() is of
> > > expected form.
> > > 
> > > Signed-off-by: Jan Kara <jack@suse.cz>
> > > ---
> > 
> > Looks good to me. Thanks Jan.
> > 
> > Reviewed-by: Brian Foster <bfoster@redhat.com>
>   Ping Dave? Are you going to pick up this patch?

I did - it's already in Linus' tree for 3.16:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/fs/xfs/xfs_alloc.c?id=30265117ee1e23fa91920f337a3ea91207f700dc

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH v2] xfs: Fix rounding in xfs_alloc_fix_len()
  2014-06-13 23:56     ` Dave Chinner
@ 2014-06-16  9:00       ` Jan Kara
  0 siblings, 0 replies; 5+ messages in thread
From: Jan Kara @ 2014-06-16  9:00 UTC (permalink / raw)
  To: Dave Chinner; +Cc: Brian Foster, xfs, Jan Kara, dchinner

On Sat 14-06-14 09:56:22, Dave Chinner wrote:
> On Fri, Jun 13, 2014 at 05:02:07PM +0200, Jan Kara wrote:
> > On Wed 04-06-14 14:44:40, Brian Foster wrote:
> > > On Wed, Jun 04, 2014 at 06:53:53PM +0200, Jan Kara wrote:
> > > > Rounding in xfs_alloc_fix_len() is wrong. As the comment states, the
> > > > result should be a number of a form (k*prod+mod) however due to sign
> > > > mistake the result is different. As a result allocations on raid arrays
> > > > could be misaligned in some cases.
> > > > 
> > > > This also seems to fix occasional assertion failure:
> > > > 	XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0)
> > > > in xfs_alloc_ag_vextent_size().
> > > > 
> > > > Also add an assertion that the result of xfs_alloc_fix_len() is of
> > > > expected form.
> > > > 
> > > > Signed-off-by: Jan Kara <jack@suse.cz>
> > > > ---
> > > 
> > > Looks good to me. Thanks Jan.
> > > 
> > > Reviewed-by: Brian Foster <bfoster@redhat.com>
> >   Ping Dave? Are you going to pick up this patch?
> 
> I did - it's already in Linus' tree for 3.16:
> 
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/fs/xfs/xfs_alloc.c?id=30265117ee1e23fa91920f337a3ea91207f700dc
  Ah, sorry. I was expecting some email about acceptance. I'll check the git
tree next time.

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2014-06-16  9:00 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-06-04 16:53 [PATCH v2] xfs: Fix rounding in xfs_alloc_fix_len() Jan Kara
2014-06-04 18:44 ` Brian Foster
2014-06-13 15:02   ` Jan Kara
2014-06-13 23:56     ` Dave Chinner
2014-06-16  9:00       ` Jan Kara

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