virtiofsd: Add attr_flags to fuse_entry_param

fuse_entry_param is converted to fuse_attr on the line (by
fill_entry()), so it should have a member that mirrors fuse_attr.flags.

fill_entry() should then copy this fuse_entry_param.attr_flags to
fuse_attr.flags.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200909184028.262297-4-mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

tools/virtiofsd/fuse_lowlevel.c

@@ -329,7 +329,8 @@ static unsigned int calc_timeout_nsec(double t)
     }
 }
 
-static void fill_entry(struct fuse_entry_out *arg,
+static void fill_entry(struct fuse_session *se,
+                       struct fuse_entry_out *arg,
                        const struct fuse_entry_param *e)
 {
     *arg = (struct fuse_entry_out){
@@ -341,6 +342,10 @@ static void fill_entry(struct fuse_entry_out *arg,
         .attr_valid_nsec = calc_timeout_nsec(e->attr_timeout),
     };
     convert_stat(&e->attr, &arg->attr);
+
+    if (se->conn.capable & FUSE_CAP_ATTR_FLAGS) {
+        arg->attr.flags = e->attr_flags;
+    }
 }
 
 /*
@@ -365,7 +370,7 @@ size_t fuse_add_direntry_plus(fuse_req_t req, char *buf, size_t bufsize,
 
     struct fuse_direntplus *dp = (struct fuse_direntplus *)buf;
     memset(&dp->entry_out, 0, sizeof(dp->entry_out));
-    fill_entry(&dp->entry_out, e);
+    fill_entry(req->se, &dp->entry_out, e);
 
     struct fuse_dirent *dirent = &dp->dirent;
     *dirent = (struct fuse_dirent){
@@ -403,7 +408,7 @@ int fuse_reply_entry(fuse_req_t req, const struct fuse_entry_param *e)
     size_t size = sizeof(arg);
 
     memset(&arg, 0, sizeof(arg));
-    fill_entry(&arg, e);
+    fill_entry(req->se, &arg, e);
     return send_reply_ok(req, &arg, size);
 }
 
@@ -416,7 +421,7 @@ int fuse_reply_create(fuse_req_t req, const struct fuse_entry_param *e,
     struct fuse_open_out *oarg = (struct fuse_open_out *)(buf + entrysize);
 
     memset(buf, 0, sizeof(buf));
-    fill_entry(earg, e);
+    fill_entry(req->se, earg, e);
     fill_open(oarg, f);
     return send_reply_ok(req, buf, entrysize + sizeof(struct fuse_open_out));
 }

tools/virtiofsd/fuse_lowlevel.h

@@ -102,6 +102,11 @@ struct fuse_entry_param {
      *  large value.
      */
     double entry_timeout;
+
+    /**
+     * Flags for fuse_attr.flags that do not fit into attr.
+     */
+    uint32_t attr_flags;
 };
 
 /**