[PATCH 2/3] xen/balloon: make the balloon wait interruptible

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

So it can be killed, or else processes can get hung indefinitely
waiting for balloon pages.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
---
 drivers/xen/balloon.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 3cb10ed32557..292413b27575 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -568,11 +568,13 @@ static int add_ballooned_pages(int nr_pages)
        if (xen_hotplug_unpopulated) {
                st = reserve_additional_memory();
                if (st != BP_ECANCELED) {
+                       int rc;
+
                        mutex_unlock(&balloon_mutex);
-                       wait_event(balloon_wq,
+                       rc = wait_event_interruptible(balloon_wq,
                                   !list_empty(&ballooned_pages));
                        mutex_lock(&balloon_mutex);
-                       return 0;
+                       return rc ? -ENOMEM : 0;
                }
        }
 
-- 
2.27.0