mount: Remove warning for impending timestamp expiry

Take out this, this hmm, well say 'officious' warning about timestamp expiry in 2038.
A nicer approach would be to make it configurable via kernel_config

Basically this reverts http://lkml.iu.edu/hypermail/linux/kernel/1908.2/01441.html

fs/namespace.c

@@ -2592,27 +2592,6 @@ static void set_mount_attributes(struct mount *mnt, unsigned int mnt_flags)
 	touch_mnt_namespace(mnt->mnt_ns);
 }
 
-static void mnt_warn_timestamp_expiry(struct path *mountpoint, struct vfsmount *mnt)
-{
-	struct super_block *sb = mnt->mnt_sb;
-
-	if (!__mnt_is_readonly(mnt) &&
-	   (ktime_get_real_seconds() + TIME_UPTIME_SEC_MAX > sb->s_time_max)) {
-		char *buf = (char *)__get_free_page(GFP_KERNEL);
-		char *mntpath = buf ? d_path(mountpoint, buf, PAGE_SIZE) : ERR_PTR(-ENOMEM);
-		struct tm tm;
-
-		time64_to_tm(sb->s_time_max, 0, &tm);
-
-		pr_warn("%s filesystem being %s at %s supports timestamps until %04ld (0x%llx)\n",
-			sb->s_type->name,
-			is_mounted(mnt) ? "remounted" : "mounted",
-			mntpath,
-			tm.tm_year+1900, (unsigned long long)sb->s_time_max);
-
-		free_page((unsigned long)buf);
-	}
-}
 
 /*
  * Handle reconfiguration of the mountpoint only without alteration of the
@@ -2646,8 +2625,6 @@ static int do_reconfigure_mnt(struct path *path, unsigned int mnt_flags)
 	unlock_mount_hash();
 	up_read(&sb->s_umount);
 
-	mnt_warn_timestamp_expiry(path, &mnt->mnt);
-
 	return ret;
 }
 
@@ -2693,8 +2670,6 @@ static int do_remount(struct path *path, int ms_flags, int sb_flags,
 		up_write(&sb->s_umount);
 	}
 
-	mnt_warn_timestamp_expiry(path, &mnt->mnt);
-
 	put_fs_context(fc);
 	return err;
 }
@@ -2962,8 +2937,6 @@ static int do_new_mount_fc(struct fs_context *fc, struct path *mountpoint,
 	if (IS_ERR(mnt))
 		return PTR_ERR(mnt);
 
-	mnt_warn_timestamp_expiry(mountpoint, mnt);
-
 	mp = lock_mount(mountpoint);
 	if (IS_ERR(mp)) {
 		mntput(mnt);