xfs: add blockdev name to kthreads

This allows to see in `ps` and similar tools which kthreads are
allotted to which block device/filesystem, similar to what jbd2
does. As the process name is a fixed 16-char array, no extra
space is needed in tasks.

  PID TTY      STAT   TIME COMMAND
    2 ?        S      0:00 [kthreadd]
  197 ?        S      0:00  \_ [jbd2/sda2-8]
  198 ?        S      0:00  \_ [ext4-dio-unwrit]
  204 ?        S      0:00  \_ [flush-8:0]
 2647 ?        S      0:00  \_ [xfs_mru_cache]
 2648 ?        S      0:00  \_ [xfslogd/0]
 2649 ?        S      0:00  \_ [xfsdatad/0]
 2650 ?        S      0:00  \_ [xfsconvertd/0]
 2651 ?        S      0:00  \_ [xfsbufd/ram0]
 2652 ?        S      0:00  \_ [xfsaild/ram0]
 2653 ?        S      0:00  \_ [xfssyncd/ram0]

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 29f1edc..e8ad6dd 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -789,18 +789,18 @@
 	 * Setup xfs_mount buffer target pointers
 	 */
 	error = ENOMEM;
-	mp->m_ddev_targp = xfs_alloc_buftarg(ddev, 0);
+	mp->m_ddev_targp = xfs_alloc_buftarg(ddev, 0, mp->m_fsname);
 	if (!mp->m_ddev_targp)
 		goto out_close_rtdev;
 
 	if (rtdev) {
-		mp->m_rtdev_targp = xfs_alloc_buftarg(rtdev, 1);
+		mp->m_rtdev_targp = xfs_alloc_buftarg(rtdev, 1, mp->m_fsname);
 		if (!mp->m_rtdev_targp)
 			goto out_free_ddev_targ;
 	}
 
 	if (logdev && logdev != ddev) {
-		mp->m_logdev_targp = xfs_alloc_buftarg(logdev, 1);
+		mp->m_logdev_targp = xfs_alloc_buftarg(logdev, 1, mp->m_fsname);
 		if (!mp->m_logdev_targp)
 			goto out_free_rtdev_targ;
 	} else {
@@ -902,7 +902,8 @@
 	struct xfs_ail	*ailp)
 {
 	ailp->xa_target = 0;
-	ailp->xa_task = kthread_run(xfsaild, ailp, "xfsaild");
+	ailp->xa_task = kthread_run(xfsaild, ailp, "xfsaild/%s",
+				    ailp->xa_mount->m_fsname);
 	if (IS_ERR(ailp->xa_task))
 		return -PTR_ERR(ailp->xa_task);
 	return 0;