common/admin_socket: report error code as part of output string

This isn't ideal, but it's better than nothing.

Net behavior change here is that calling an non-existant command now
succeeds with an error message instead of exiting with an error code
and no informative output.

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/common/admin_socket.cc b/src/common/admin_socket.cc
index e71e6543b7306f03c999751dc710064f7fc14213..c5af715090b3b52703edc8e3ee9f78b1df655335 100644 (file)
--- a/src/common/admin_socket.cc
+++ b/src/common/admin_socket.cc
@@ -284,7 +284,7 @@ void AdminSocket::chmod(mode_t mode)
   }
 }
 
-bool AdminSocket::do_accept()
+void AdminSocket::do_accept()
 {
   struct sockaddr_un address;
   socklen_t address_length = sizeof(address);
@@ -295,7 +295,7 @@ bool AdminSocket::do_accept()
     int err = errno;
     lderr(m_cct) << "AdminSocket: do_accept error: '"
                           << cpp_strerror(err) << dendl;
-    return false;
+    return;
   }
   ldout(m_cct, 30) << "AdminSocket: finished accept" << dendl;
 
@@ -310,7 +310,7 @@ bool AdminSocket::do_accept()
                     << cpp_strerror(ret) << dendl;
       }
       retry_sys_call(::close, connection_fd);
-      return false;
+      return;
     }
     if (cmd[0] == '\0') {
       // old protocol: __be32
@@ -344,7 +344,7 @@ bool AdminSocket::do_accept()
     if (++pos >= sizeof(cmd)) {
       lderr(m_cct) << "AdminSocket: error reading request too long" << dendl;
       retry_sys_call(::close, connection_fd);
-      return false;
+      return;
     }
   }
 
@@ -355,28 +355,27 @@ bool AdminSocket::do_accept()
 
   // Unfortunately, the asok wire protocol does not let us pass an error code,
   // and many asok command implementations return helpful error strings.  So,
-  // let's interpret all but -ENOSYS as a "success" so that the user can still
-  // see those messages.  This provides the same behavior as what users saw
-  // pre-octopus; the only drawback is that net new 'tell-style' commands that
-  // return error codes will also be seen as "success" via asok unless/until
-  // we extend the socket protocol.
-  if (rval != -ENOSYS) {
-    rval = 0; // sigh.. fixme someday!
-    uint32_t len = htonl(out.length());
-    int ret = safe_write(connection_fd, &len, sizeof(len));
-    if (ret < 0) {
-      lderr(m_cct) << "AdminSocket: error writing response length "
-          << cpp_strerror(ret) << dendl;
-      rval = -EIO;
-    } else {
-      if (out.write_fd(connection_fd) < 0) {
-       rval = -EIO;
-      }
+  // let's prepend an error string to the output if there is an error code.
+  if (rval < 0) {
+    ostringstream ss;
+    ss << "ERROR: " << cpp_strerror(rval) << "\n";
+    bufferlist o;
+    o.append(ss.str());
+    o.claim_append(out);
+    out.claim_append(o);
+  }
+  uint32_t len = htonl(out.length());
+  int ret = safe_write(connection_fd, &len, sizeof(len));
+  if (ret < 0) {
+    lderr(m_cct) << "AdminSocket: error writing response length "
+                << cpp_strerror(ret) << dendl;
+  } else {
+    if (out.write_fd(connection_fd) < 0) {
+      lderr(m_cct) << "AdminSocket: error writing response payload "
+                  << cpp_strerror(ret) << dendl;
     }
   }
-
   retry_sys_call(::close, connection_fd);
-  return rval >= 0;
 }
 
 void AdminSocket::do_tell_queue()

diff --git a/src/common/admin_socket.h b/src/common/admin_socket.h
index a866cae7685e5e31c81369db1001a79a23d30c80..d38dd7c3998f6f3107167a52e9e3998049dc5a96 100644 (file)
--- a/src/common/admin_socket.h
+++ b/src/common/admin_socket.h
@@ -123,7 +123,7 @@ private:
 
   std::thread th;
   void entry() noexcept;
-  bool do_accept();
+  void do_accept();
   void do_tell_queue();
 
   CephContext *m_cct;