xfs: switch to multigrain timestamps

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.

Acked-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230807-mgctime-v7-11-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_trans_inode.c b/fs/xfs/libxfs/xfs_trans_inode.c
index 6b2296f..ad22656 100644 (file)
--- 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);
        ASSERT(xfs_isilocked(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->i_mtime = 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 1c1e617..2ededd3 100644 (file)
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -573,10 +573,10 @@ xfs_vn_getattr(
        stat->gid = vfsgid_into_kgid(vfsgid);
        stat->ino = ip->i_ino;
        stat->atime = inode->i_atime;
-       stat->mtime = inode->i_mtime;
-       stat->ctime = inode_get_ctime(inode);
        stat->blocks = XFS_FSB_TO_BB(mp, ip->i_nblocks + ip->i_delayed_blks);
 
+       fill_mg_cmtime(stat, request_mask, inode);
+
        if (xfs_has_v3inodes(mp)) {
                if (request_mask & STATX_BTIME) {
                        stat->result_mask |= STATX_BTIME;
@@ -917,7 +917,7 @@ xfs_setattr_size(
        if (newsize != oldsize &&
            !(iattr->ia_valid & (ATTR_CTIME | ATTR_MTIME))) {
                iattr->ia_ctime = iattr->ia_mtime =
-                       current_time(inode);
+                       current_mgtime(inode);
                iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME;
        }
 

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 8185102..4b10edb 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -2009,7 +2009,7 @@ static struct file_system_type xfs_fs_type = {
        .init_fs_context        = xfs_init_fs_context,
        .parameters             = xfs_fs_parameters,
        .kill_sb                = kill_block_super,
-       .fs_flags               = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
+       .fs_flags               = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME,
 };
 MODULE_ALIAS_FS("xfs");