[PATCH 15/24] DAX: virtiofsd: Perform an unmap on destroy

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Force unmap all remaining dax cache entries on a destroy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 tools/virtiofsd/passthrough_ll.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index badac23fef..21ddb434ae 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -2947,6 +2947,17 @@ static void lo_destroy(void *userdata, struct 
fuse_session *se)
 {
     struct lo_data *lo = (struct lo_data *)userdata;
 
+    if (fuse_lowlevel_is_virtio(se)) {
+        VhostUserFSSlaveMsg msg = { 0 };
+
+        msg.len[0] = ~(uint64_t)0; /* Special: means 'all' */
+        msg.c_offset[0] = 0;
+        if (fuse_virtio_unmap(se, &msg)) {
+            fuse_log(FUSE_LOG_ERR, "%s: unmap during destroy failed\n",
+                     __func__);
+        }
+    }
+
     pthread_mutex_lock(&lo->mutex);
     while (true) {
         GHashTableIter iter;
-- 
2.29.2