On Thu, 2017-05-11 at 14:49 +0200, Arnd Bergmann wrote:
> gcc-7 flags the use of integer math inside of a condition
> as a potential bug:
>
> fs/xfs/xfs_bmap_util.c: In function 'xfs_swap_extents_check_format':
> fs/xfs/xfs_bmap_util.c:1619:8: error: '<<' in boolean context, did you mean
> '<' ? [-Werror=int-in-bool-context]
> fs/xfs/xfs_bmap_util.c:1629:8: error: '<<' in boolean context, did you mean
> '<' ? [-Werror=int-in-bool-context]
>
> This one is clearly fine, and we can add a comparison to zero
> to shut up the warning.
[]
> diff --git 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_BOFF(ip) != 0) &&
As far as I can tell, this suggestion makes no sense.
$ git grep -E "define\s+XFS_IFORK_BOFF"
fs/xfs/libxfs/xfs_inode_fork.h:#define XFS_IFORK_BOFF(ip)
((int)((ip)->i_d.di_forkoff << 3))
$ git grep -w di_forkoff|grep -P "\w+\s+di_forkoff\s*;"
fs/xfs/libxfs/xfs_format.h: __u8 di_forkoff; /* attr fork
offs, <<3 for 64b align */
fs/xfs/libxfs/xfs_inode_buf.h: __uint8_t di_forkoff; /* attr fork
offs, <<3 for 64b align */
fs/xfs/libxfs/xfs_log_format.h: __uint8_t di_forkoff; /* attr fork
offs, <<3 for 64b align */
