From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:40932 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753AbdFCEuq (ORCPT ); Sat, 3 Jun 2017 00:50:46 -0400 Date: Fri, 2 Jun 2017 21:50:41 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH] xfs: avoid -Wint-in-bool-context warning in xfs_bmap_util.c Message-ID: <20170603045041.GF5636@birch.djwong.org> References: <20170603042107.17469-1-ebiggers3@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170603042107.17469-1-ebiggers3@gmail.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Eric Biggers Cc: linux-xfs@vger.kernel.org, Eric Biggers On Fri, Jun 02, 2017 at 09:21:07PM -0700, Eric Biggers wrote: > From: Eric Biggers > > XFS triggers gcc 7's -Wint-in-bool-context warning (on by default with > -Wall), which warns about arithmetic in a boolean context that has no > effect on the result: > > In file included from fs/xfs/xfs_inode.h:22:0, > from fs/xfs/xfs_bmap_util.c:29: > fs/xfs/xfs_bmap_util.c: In function ‘xfs_swap_extents_check_format’: > fs/xfs/libxfs/xfs_inode_fork.h:90:30: warning: ‘<<’ in boolean context, did you mean ‘<’ ? [-Wint-in-bool-context] > #define XFS_IFORK_BOFF(ip) ((int)((ip)->i_d.di_forkoff << 3)) > ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > fs/xfs/xfs_bmap_util.c:1620:7: note: in expansion of macro ‘XFS_IFORK_BOFF’ > if (XFS_IFORK_BOFF(ip) && > ^~~~~~~~~~~~~~ > fs/xfs/libxfs/xfs_inode_fork.h:90:30: warning: ‘<<’ in boolean context, did you mean ‘<’ ? [-Wint-in-bool-context] > #define XFS_IFORK_BOFF(ip) ((int)((ip)->i_d.di_forkoff << 3)) > ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > fs/xfs/xfs_bmap_util.c:1630:7: note: in expansion of macro ‘XFS_IFORK_BOFF’ > if (XFS_IFORK_BOFF(tip) && > ^~~~~~~~~~~~~~ > > This is more or less a false positive, because the useless arithmetic is > just the left shift in XFS_IFORK_BOFF(). Use XFS_IFORK_Q() instead to > make the warnings go away, while having the same behavior and being more > consistent with other places in XFS which also use XFS_IFORK_Q(). > > Signed-off-by: Eric Biggers Arnd Bergmann already sent the exact same patch[1] for 4.13, but, er, thanks for spotting this! :) --D [1] https://marc.info/?l=linux-xfs&m=149498134833721&w=2 > --- > fs/xfs/xfs_bmap_util.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c > index 7ac80a1facf2..05a6fdf5976d 100644 > --- a/fs/xfs/xfs_bmap_util.c > +++ b/fs/xfs/xfs_bmap_util.c > @@ -1613,7 +1613,7 @@ xfs_swap_extents_check_format( > * extent format... > */ > if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) { > - if (XFS_IFORK_BOFF(ip) && > + if (XFS_IFORK_Q(ip) && > XFS_BMAP_BMDR_SPACE(tip->i_df.if_broot) > XFS_IFORK_BOFF(ip)) > return -EINVAL; > if (XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <= > @@ -1623,7 +1623,7 @@ xfs_swap_extents_check_format( > > /* Reciprocal target->temp btree format checks */ > if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) { > - if (XFS_IFORK_BOFF(tip) && > + if (XFS_IFORK_Q(tip) && > XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > XFS_IFORK_BOFF(tip)) > return -EINVAL; > if (XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <= > -- > 2.13.0 > > -- > 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