From d366b2bc4e89ed5807f0221afc25e66cb3d289ed Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>

Date: Wed, 9 Dec 2020 11:23:37 +0100

Subject: [PATCH 1/2] xwayland: Don't spew warnings when looking for X11

 displays

It's not important, so only show it when doing MUTTER_DEBUG=wayland.

Instead report what display numbers were eventually found.

---

 src/wayland/meta-xwayland.c | 123 +++++++++++++++++++++++++++---------

 1 file changed, 92 insertions(+), 31 deletions(-)

diff --git a/src/wayland/meta-xwayland.c b/src/wayland/meta-xwayland.c

index 15c85df69..699d5561c 100644

--- a/src/wayland/meta-xwayland.c

+++ b/src/wayland/meta-xwayland.c

@@ -146,9 +146,10 @@ meta_xwayland_is_xwayland_surface (MetaWaylandSurface *surface)

 }

 static gboolean

-try_display (int    display,

-             char **filename_out,

-             int   *fd_out)

+try_display (int      display,

+             char   **filename_out,

+             int     *fd_out,

+             GError **error)

 {

   gboolean ret = FALSE;

   char *filename;

@@ -164,11 +165,32 @@ try_display (int    display,

       char pid[11];

       char *end;

       pid_t other;

+      int read_bytes;

       fd = open (filename, O_CLOEXEC, O_RDONLY);

-      if (fd < 0 || read (fd, pid, 11) != 11)

+      if (fd < 0)

         {

-          g_warning ("can't read lock file %s: %m", filename);

+          g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                       "Failed to open lock file %s: %s",

+                       filename, g_strerror (errno));

+          goto out;

+        }

+

+      read_bytes = read (fd, pid, 11);

+      if (read_bytes != 11)

+        {

+          if (read_bytes < 0)

+            {

+              g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                           "Failed to read lock file %s: %s",

+                           filename, g_strerror (errno));

+            }

+          else

+            {

+              g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,

+                           "Failed to read lock file %s",

+                           filename);

+            }

           goto out;

         }

       close (fd);

@@ -178,7 +200,8 @@ try_display (int    display,

       other = strtol (pid, &end, 0);

       if (end != pid + 10)

         {

-          g_warning ("can't parse lock file %s", filename);

+          g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_DATA,

+                       "Can't parse lock file %s", filename);

           goto out;

         }

@@ -187,18 +210,23 @@ try_display (int    display,

           /* Process is dead. Try unlinking the lock file and trying again. */

           if (unlink (filename) < 0)

             {

-              g_warning ("failed to unlink stale lock file %s: %m", filename);

+              g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                           "Failed to unlink stale lock file %s: %m", filename);

               goto out;

             }

           goto again;

         }

+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,

+                   "Lock file %s already occupied", filename);

       goto out;

     }

   else if (fd < 0)

     {

-      g_warning ("failed to create lock file %s: %m", filename);

+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,

+                   "Failed to create lock file %s: %s",

+                   filename, g_strerror (errno));

       goto out;

     }

@@ -223,24 +251,34 @@ try_display (int    display,

 }

 static char *

-create_lock_file (int display, int *display_out)

+create_lock_file (int      display,

+                  int     *display_out,

+                  GError **error)

 {

+  g_autoptr (GError) local_error = NULL;

   char *filename;

   int fd;

-

   char pid[12];

   int size;

   int number_of_tries = 0;

-  while (!try_display (display, &filename, &fd))

+  while (!try_display (display, &filename, &fd, &local_error))

     {

+      meta_verbose ("Failed to open display %d: %s\n",

+                    display, local_error->message);

+      g_clear_error (&local_error);

+

       display++;

       number_of_tries++;

       /* If we can't get a display after 50 times, then something's wrong. Just

        * abort in this case. */

       if (number_of_tries >= 50)

-        return NULL;

+        {

+          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,

+                       "Tried to bind 50 display numbers, giving up");

+          return NULL;

+        }

     }

   /* Subtle detail: we use the pid of the wayland compositor, not the xserver

@@ -248,11 +286,22 @@ create_lock_file (int display, int *display_out)

    * it _would've_ written without either the NUL or the size clamping, hence

    * the disparity in size. */

   size = snprintf (pid, 12, "%10d\n", getpid ());

+  errno = 0;

   if (size != 11 || write (fd, pid, 11) != 11)

     {

+      if (errno != 0)

+        {

+          g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                       "Failed to write pid to lock file: %s",

+                       g_strerror (errno));

+        }

+      else

+        {

+          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,

+                       "Failed to write pid to lock file");

+        }

       unlink (filename);

       close (fd);

-      g_warning ("failed to write pid to lock file %s", filename);

       g_free (filename);

       return NULL;

     }

@@ -264,8 +313,8 @@ create_lock_file (int display, int *display_out)

 }

 static int

-bind_to_abstract_socket (int       display,

-                         gboolean *fatal)

+bind_to_abstract_socket (int        display,

+                         GError   **error)

 {

   struct sockaddr_un addr;

   socklen_t size, name_size;

@@ -274,8 +323,8 @@ bind_to_abstract_socket (int       display,

   fd = socket (PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);

   if (fd < 0)

     {

-      *fatal = TRUE;

-      g_warning ("Failed to create socket: %m");

+      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                   "Failed to create socket: %s", g_strerror (errno));

       return -1;

     }

@@ -285,17 +334,18 @@ bind_to_abstract_socket (int       display,

   size = offsetof (struct sockaddr_un, sun_path) + name_size;

   if (bind (fd, (struct sockaddr *) &addr, size) < 0)

     {

-      *fatal = errno != EADDRINUSE;

-      g_warning ("failed to bind to @%s: %m", addr.sun_path + 1);

+      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                   "Failed to bind to @%s: %s",

+                   addr.sun_path + 1, g_strerror (errno));

       close (fd);

       return -1;

     }

   if (listen (fd, 1) < 0)

     {

-      *fatal = errno != EADDRINUSE;

-      g_warning ("Failed to listen on abstract socket @%s: %m",

-                 addr.sun_path + 1);

+      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                   "Failed to listen on abstract socket @%s: %s",

+                   addr.sun_path + 1, g_strerror (errno));

       close (fd);

       return -1;

     }

@@ -304,7 +354,8 @@ bind_to_abstract_socket (int       display,

 }

 static int

-bind_to_unix_socket (int display)

+bind_to_unix_socket (int      display,

+                     GError **error)

 {

   struct sockaddr_un addr;

   socklen_t size, name_size;

@@ -321,13 +372,18 @@ bind_to_unix_socket (int display)

   unlink (addr.sun_path);

   if (bind (fd, (struct sockaddr *) &addr, size) < 0)

     {

-      g_warning ("failed to bind to %s: %m\n", addr.sun_path);

+      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                   "Failed to bind to %s: %s",

+                   addr.sun_path, g_strerror (errno));

       close (fd);

       return -1;

     }

   if (listen (fd, 1) < 0)

     {

+      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),

+                   "Failed to listen on %s: %s",

+                   addr.sun_path, g_strerror (errno));

       unlink (addr.sun_path);

       close (fd);

       return -1;

@@ -385,7 +441,6 @@ choose_xdisplay (MetaXWaylandManager *manager)

 {

   int display = 0;

   char *lock_file = NULL;

-  gboolean fatal = FALSE;

   if (display_number_override != -1)

     display = display_number_override;

@@ -394,33 +449,37 @@ choose_xdisplay (MetaXWaylandManager *manager)

   do

     {

-      lock_file = create_lock_file (display, &display);

+      g_autoptr (GError) error = NULL;

+

+      lock_file = create_lock_file (display, &display, &error);

       if (!lock_file)

         {

-          g_warning ("Failed to create an X lock file");

+          g_warning ("Failed to create an X lock file: %s", error->message);

           return FALSE;

         }

-      manager->abstract_fd = bind_to_abstract_socket (display, &fatal);

+      manager->abstract_fd = bind_to_abstract_socket (display, &error);

       if (manager->abstract_fd < 0)

         {

           unlink (lock_file);

-          if (!fatal)

+          if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_ADDRESS_IN_USE))

             {

+              meta_verbose ("Failed to bind abstract socket: %s\n", error->message);

               display++;

               continue;

             }

           else

             {

-              g_warning ("Failed to bind abstract socket");

+              g_warning ("Failed to bind abstract socket: %s", error->message);

               return FALSE;

             }

         }

-      manager->unix_fd = bind_to_unix_socket (display);

+      manager->unix_fd = bind_to_unix_socket (display, &error);

       if (manager->unix_fd < 0)

         {

+          meta_verbose ("Failed to bind unix socket: %s\n", error->message);

           unlink (lock_file);

           close (manager->abstract_fd);

           display++;

@@ -435,6 +494,8 @@ choose_xdisplay (MetaXWaylandManager *manager)

   manager->display_name = g_strdup_printf (":%d", manager->display_index);

   manager->lock_file = lock_file;

+  g_message ("Using X11 display %s for Xwayland", manager->display_name);

+

   return TRUE;

 }

-- 

2.29.2