[PATCH 4.19 167/168] xen/balloon: make the balloon wait interruptible

Greg Kroah-Hartman
2020-08-17T17:20:18Z

From: Roger Pau Monne <roger.pau@citrix.com>

commit 88a479ff6ef8af7f07e11593d58befc644244ff7 upstream.

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

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200727091342.52325-3-roger.pau@citrix.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/xen/balloon.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -570,11 +570,13 @@ static int add_ballooned_pages(int nr_pa
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;
}
}