[RFC PATCH 9/9] virtiofsd: (work around) Comment qsort in inflight I/O tracking

[Jiachen Zhang <zhangjiachen.jaycee@bytedance.com>]

This is a work around. The qsort function will malloc memory instead of use
stack memory when the resubmit_num is larger than 64 (total size larger than
1024 Bytes). This will cause seccomp kill virtiofsd, so we comment qsort.
This work around will not affect the correctness of inflight I/O tracking.

Signed-off-by: Jiachen Zhang <zhangjiachen.jaycee@bytedance.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
---
 contrib/libvhost-user/libvhost-user.c | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index 8c97013e59..c226d5d915 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -1167,20 +1167,6 @@ vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
     return true;
 }
 
-static int
-inflight_desc_compare(const void *a, const void *b)
-{
-    VuVirtqInflightDesc *desc0 = (VuVirtqInflightDesc *)a,
-                        *desc1 = (VuVirtqInflightDesc *)b;
-
-    if (desc1->counter > desc0->counter &&
-        (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
-        return 1;
-    }
-
-    return -1;
-}
-
 static int
 vu_check_queue_inflights(VuDev *dev, VuVirtq *vq)
 {
@@ -1236,10 +1222,6 @@ vu_check_queue_inflights(VuDev *dev, VuVirtq *vq)
             }
         }
 
-        if (vq->resubmit_num > 1) {
-            qsort(vq->resubmit_list, vq->resubmit_num,
-                  sizeof(VuVirtqInflightDesc), inflight_desc_compare);
-        }
         vq->counter = vq->resubmit_list[0].counter + 1;
     }
 
-- 
2.20.1