[PATCH] mdadm: add man page for --add-journal

[Song Liu <songliubraving@fb.com>]

Add the following to man page:

--add-journal
      Recreate journal for RAID-4/5/6 array that losts journal
      devices. In current implementation, this command cannot
      add journal to an array that had failed journal.  To
      avoid  interrupting  on-going  write  opertions,
      --add-journal only works for array in Read-Only state.

Reported-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
---
 mdadm.8.in | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/mdadm.8.in b/mdadm.8.in
index 1a04bd1..a335c53 100644
--- a/mdadm.8.in
+++ b/mdadm.8.in
@@ -1444,6 +1444,14 @@ number. The receiving node must acknowledge this message
 with \-\-cluster\-confirm. Valid arguments are <slot>:<devicename> in case
 the device is found or <slot>:missing in case the device is not found.
 
+.TP
+.BR \-\-add-journal
+Recreate journal for RAID-4/5/6 array that losts journal devices. In current
+implementation, this command cannot add journal to an array that had failed
+journal. To avoid interrupting on-going write opertions,
+.B \-\-add-journal
+only works for array in Read-Only state.
+
 .P
 Each of these options requires that the first device listed is the array
 to be acted upon, and the remainder are component devices to be added,
-- 
2.8.0.rc2