block/iscsi: take iscsilun->mutex in iscsi_timed_check_events()

Commit d045c466d9e62b4321fadf586d024d54ddfd8bd4 ("iscsi: do not use
aio_context_acquire/release") introduced iscsilun->mutex but appears to
have overlooked iscsi_timed_check_events() when introducing the mutex.

iscsi_service() and iscsi_set_events() must be called with
iscsilun->mutex held.

iscsi_timed_check_events() is invoked from the AioContext and does not
take the mutex.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180203061621.7033-3-stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/block/iscsi.c b/block/iscsi.c
index a4e3730a82..1924a2b58e 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -344,6 +344,8 @@ static void iscsi_timed_check_events(void *opaque)
 {
     IscsiLun *iscsilun = opaque;
 
+    qemu_mutex_lock(&iscsilun->mutex);
+
     /* check for timed out requests */
     iscsi_service(iscsilun->iscsi, 0);
 
@@ -356,6 +358,8 @@ static void iscsi_timed_check_events(void *opaque)
      * to return to service once this situation changes. */
     iscsi_set_events(iscsilun);
 
+    qemu_mutex_unlock(&iscsilun->mutex);
+
     timer_mod(iscsilun->event_timer,
               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
 }