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From:   Roger Pau Monne <roger.pau@citrix.com>
To:     <linux-kernel@vger.kernel.org>
CC:     Roger Pau Monne <roger.pau@citrix.com>, <stable@vger.kernel.org>,
        "Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
        Juergen Gross <jgross@suse.com>,
        Stefano Stabellini <sstabellini@kernel.org>,
        <xen-devel@lists.xenproject.org>
Subject: [PATCH 2/3] xen/balloon: make the balloon wait interruptible
Date:   Thu, 23 Jul 2020 10:45:22 +0200
Message-ID: <20200723084523.42109-3-roger.pau@citrix.com>
In-Reply-To: <20200723084523.42109-1-roger.pau@citrix.com>
References: <20200723084523.42109-1-roger.pau@citrix.com>
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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>
Cc: stable@vger.kernel.org
---
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: xen-devel@lists.xenproject.org
---
 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