Re: [PATCH v6 6/9] xfs: switch to multigrain timestamps

Darrick J. Wong
2024-07-15T18:47:44Z

On Mon, Jul 15, 2024 at 08:48:57AM -0400, Jeff Layton wrote:
> Enable multigrain timestamps, which should ensure that there is an
> apparent change to the timestamp whenever it has been written after
> being actively observed via getattr.
>
> Also, anytime the mtime changes, the ctime must also change, and those
> are now the only two options for xfs_trans_ichgtime. Have that function
> unconditionally bump the ctime, and ASSERT that XFS_ICHGTIME_CHG is
> always set.
>
> Finally, stop setting STATX_CHANGE_COOKIE in getattr, since the ctime
> should give us better semantics now.
>
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

Looks good,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> fs/xfs/libxfs/xfs_trans_inode.c | 6 +++---
> fs/xfs/xfs_iops.c | 10 +++-------
> fs/xfs/xfs_super.c | 2 +-
> 3 files changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_trans_inode.c b/fs/xfs/libxfs/xfs_trans_inode.c
> index 69fc5b981352..1f3639bbf5f0 100644
> --- a/fs/xfs/libxfs/xfs_trans_inode.c
> +++ b/fs/xfs/libxfs/xfs_trans_inode.c
> @@ -62,12 +62,12 @@ xfs_trans_ichgtime(
> ASSERT(tp);
> xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
>
> - tv = current_time(inode);
> + /* If the mtime changes, then ctime must also change */
> + ASSERT(flags & XFS_ICHGTIME_CHG);
>
> + tv = inode_set_ctime_current(inode);
> if (flags & XFS_ICHGTIME_MOD)
> inode_set_mtime_to_ts(inode, tv);
> - if (flags & XFS_ICHGTIME_CHG)
> - inode_set_ctime_to_ts(inode, tv);
> if (flags & XFS_ICHGTIME_CREATE)
> ip->i_crtime = tv;
> }
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index a00dcbc77e12..d25872f818fa 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -592,8 +592,9 @@ xfs_vn_getattr(
> stat->gid = vfsgid_into_kgid(vfsgid);
> stat->ino = ip->i_ino;
> stat->atime = inode_get_atime(inode);
> - stat->mtime = inode_get_mtime(inode);
> - stat->ctime = inode_get_ctime(inode);
> +
> + fill_mg_cmtime(stat, request_mask, inode);
> +
> stat->blocks = XFS_FSB_TO_BB(mp, ip->i_nblocks + ip->i_delayed_blks);
>
> if (xfs_has_v3inodes(mp)) {
> @@ -603,11 +604,6 @@ xfs_vn_getattr(
> }
> }
>
> - if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
> - stat->change_cookie = inode_query_iversion(inode);
> - stat->result_mask |= STATX_CHANGE_COOKIE;
> - }
> -
> /*
> * Note: If you add another clause to set an attribute flag, please
> * update attributes_mask below.
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 27e9f749c4c7..210481b03fdb 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -2052,7 +2052,7 @@ static struct file_system_type xfs_fs_type = {
> .init_fs_context = xfs_init_fs_context,
> .parameters = xfs_fs_parameters,
> .kill_sb = xfs_kill_sb,
> - .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
> + .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME,
> };
> MODULE_ALIAS_FS("xfs");
>
>
> --
> 2.45.2
>
>