| Message ID | 1482436822-31546-3-git-send-email-hch@lst.de (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Thu, Dec 22, 2016 at 09:00:19PM +0100, Christoph Hellwig wrote: > The way the alignment field is used the minimum possible alignment is 1. > By setting it to 0 we'll mess up calculations that rely on this. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > fs/xfs/libxfs/xfs_bmap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c > index 2760bc3..19c05e9 100644 > --- a/fs/xfs/libxfs/xfs_bmap.c > +++ b/fs/xfs/libxfs/xfs_bmap.c > @@ -3796,7 +3796,7 @@ xfs_bmap_btalloc( > */ > args.type = atype; > args.fsbno = ap->blkno; > - args.alignment = 0; > + args.alignment = 1; Ok, but we have the following near the top of xfs_alloc_vextent(): if (args->alignment == 0) args->alignment = 1; ... so I'm not sure the commit log description is accurate. That aside: Reviewed-by: Brian Foster <bfoster@redhat.com> Brian > if ((error = xfs_alloc_vextent(&args))) > return error; > } > -- > 2.1.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jan 04, 2017 at 09:34:05AM -0500, Brian Foster wrote: > Ok, but we have the following near the top of xfs_alloc_vextent(): > > if (args->alignment == 0) > args->alignment = 1; > > ... so I'm not sure the commit log description is accurate. That aside: > > Reviewed-by: Brian Foster <bfoster@redhat.com> Well, in that case we might not actually need it. This was just a a drive-by patch from investigating what the alignmnet - 1 mean in the allocator. Either way this could be cleaned up, but probably shouldn't be in a minimal bugfix series. -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Jan 08, 2017 at 11:31:34AM +0100, Christoph Hellwig wrote: > On Wed, Jan 04, 2017 at 09:34:05AM -0500, Brian Foster wrote: > > Ok, but we have the following near the top of xfs_alloc_vextent(): > > > > if (args->alignment == 0) > > args->alignment = 1; > > > > ... so I'm not sure the commit log description is accurate. That aside: > > > > Reviewed-by: Brian Foster <bfoster@redhat.com> > > Well, in that case we might not actually need it. This was just a > a drive-by patch from investigating what the alignmnet - 1 mean in > the allocator. > > Either way this could be cleaned up, but probably shouldn't be in > a minimal bugfix series. We could also just replace it with something like ASSERT(args->alignment > 0) before the use of (alignment - 1), which is kind of self-documenting (but still probably not worth a patch on its own). But fair enough either way... Brian > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 2760bc3..19c05e9 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3796,7 +3796,7 @@ xfs_bmap_btalloc( */ args.type = atype; args.fsbno = ap->blkno; - args.alignment = 0; + args.alignment = 1; if ((error = xfs_alloc_vextent(&args))) return error; }
The way the alignment field is used the minimum possible alignment is 1. By setting it to 0 we'll mess up calculations that rely on this. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/libxfs/xfs_bmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)