On Tue, Mar 19, 2024 at 05:19:51PM +1000, Christoph Hellwig wrote:
> Add a strategic IS_ENABLED to let the compiler eliminate the unused
> non-crc code is CONFIG_XFS_SUPPORT_V4 is disabled.
>
> This saves almost 20k worth of .text for my .config:
>
> $ size xfs.o.*
> text data bss dec hex filename
> 1351126 294836 592 1646554 191fda xfs.o.new
> 1371453 294868 592 1666913 196f61 xfs.o.old
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> fs/xfs/xfs_mount.h | 7 ++++++-
> fs/xfs/xfs_super.c | 22 +++++++++++++---------
> 2 files changed, 19 insertions(+), 10 deletions(-)
>
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index e880aa48de68bb..24fe6e7913c49f 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -327,6 +327,12 @@ static inline void xfs_add_ ## name (struct xfs_mount *mp) \
> xfs_sb_version_add ## name(&mp->m_sb); \
> }
>
> +static inline bool xfs_has_crc(struct xfs_mount *mp)
> +{
> + return IS_ENABLED(CONFIG_XFS_SUPPORT_V4) &&
> + (mp->m_features & XFS_FEAT_CRC);
Can you save even more text bytes by defining
xfs_has_{nlink,v3inodes,projid32,lazysbcount,pquotino,attr2} to 1?
And I guess defining noattr2 to 0?
--D
> +}
> +
> /* Superblock features */
> __XFS_ADD_FEAT(attr, ATTR)
> __XFS_HAS_FEAT(nlink, NLINK)
> @@ -341,7 +347,6 @@ __XFS_HAS_FEAT(lazysbcount, LAZYSBCOUNT)
> __XFS_ADD_FEAT(attr2, ATTR2)
> __XFS_HAS_FEAT(parent, PARENT)
> __XFS_ADD_FEAT(projid32, PROJID32)
> -__XFS_HAS_FEAT(crc, CRC)
> __XFS_HAS_FEAT(v3inodes, V3INODES)
> __XFS_HAS_FEAT(pquotino, PQUOTINO)
> __XFS_HAS_FEAT(ftype, FTYPE)
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 6828c48b15e9bd..7d972e1179255b 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1580,17 +1580,21 @@ xfs_fs_fill_super(
> if (error)
> goto out_free_sb;
>
> - /* V4 support is undergoing deprecation. */
> - if (!xfs_has_crc(mp)) {
> -#ifdef CONFIG_XFS_SUPPORT_V4
> + /*
> + * V4 support is undergoing deprecation.
> + *
> + * Note: this has to use an open coded m_features check as xfs_has_crc
> + * always returns false for !CONFIG_XFS_SUPPORT_V4.
> + */
> + if (!(mp->m_features & XFS_FEAT_CRC)) {
> + if (!IS_ENABLED(CONFIG_XFS_SUPPORT_V4)) {
> + xfs_warn(mp,
> + "Deprecated V4 format (crc=0) not supported by kernel.");
> + error = -EINVAL;
> + goto out_free_sb;
> + }
> xfs_warn_once(mp,
> "Deprecated V4 format (crc=0) will not be supported after September 2030.");
> -#else
> - xfs_warn(mp,
> - "Deprecated V4 format (crc=0) not supported by kernel.");
> - error = -EINVAL;
> - goto out_free_sb;
> -#endif
> }
>
> /* ASCII case insensitivity is undergoing deprecation. */
> --
> 2.39.2
>
>
