MD: add journal with array suspended

Hot add journal disk in recovery thread context brings a lot of trouble
as IO could be running. Unlike spare disk hot add, adding journal disk
with array suspended makes more sense and implmentation is much easier.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 29a4bbf62be5..8753dee3983b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2455,15 +2455,20 @@ static int add_bound_rdev(struct md_rdev *rdev)
 {
         struct mddev *mddev = rdev->mddev;
         int err = 0;
+        bool add_journal = test_bit(Journal, &rdev->flags);
 
-        if (!mddev->pers->hot_remove_disk) {
+        if (!mddev->pers->hot_remove_disk || add_journal) {
                 /* If there is hot_add_disk but no hot_remove_disk
                  * then added disks for geometry changes,
                  * and should be added immediately.
                  */
                 super_types[mddev->major_version].
                         validate_super(mddev, rdev);
+                if (add_journal)
+                        mddev_suspend(mddev);
                 err = mddev->pers->hot_add_disk(mddev, rdev);
+                if (add_journal)
+                        mddev_resume(mddev);
                 if (err) {
                         unbind_rdev_from_array(rdev);
                         export_rdev(rdev);