From 8345b59a168f464ee7d488ec0dc25b0203fa2e1f Mon Sep 17 00:00:00 2001
From: Hong Jen Yee (PCMan) <pcman.tw@gmail.com>
Date: Sat, 26 Feb 2011 16:43:53 +0800
Subject: [PATCH] Fix #34710 - [udisks] CD-ROM polling failed due to O_EXCL flag (poller.c).

---
 src/poller.c |   51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 51 insertions(+), 0 deletions(-)

Index: udisks-1.0.2/src/poller.c
===================================================================
--- udisks-1.0.2.orig/src/poller.c	2011-03-11 11:57:48.000000000 +0100
+++ udisks-1.0.2/src/poller.c	2011-03-11 11:58:28.000000000 +0100
@@ -119,6 +119,41 @@
 
 static guint poller_timeout_id = 0;
 
+
+/* Check if a filesystem on a special device file is mounted */
+/* Reference: [linux/hotplug/udev.git]/extras/cdrom_id/cdrom_id.c */
+static gboolean
+is_mounted (const gchar *device_file)
+{
+  struct stat statbuf;
+  int major, minor;
+  FILE* f;
+  gboolean ret;
+  gchar line[100];
+
+  if (stat (device_file, &statbuf) < 0)
+      return FALSE;
+
+  ret = FALSE;
+  f = fopen ("/proc/self/mountinfo", "r");
+  if (f)
+    {
+      while (fgets(line, 100, f))
+        {
+          if (sscanf(line, "%*s %*s %d:%d", &major, &minor) == 2)
+            {
+              if (makedev(major, minor) == statbuf.st_rdev)
+                {
+                  ret = TRUE;
+                  break;
+                }
+            }
+        }
+      fclose(f);
+    }
+  return ret;
+}
+
 static void
 poller_check_ide_cdrom (int fd, PollerDevice *device)
 {
@@ -193,6 +228,22 @@
        *  - use O_EXCL to avoid interferring with cd burning software / audio playback / etc
        */
       fd = open (device->dev_path, O_RDONLY | O_NONBLOCK | O_EXCL);
+      if (fd == -1 && errno == EBUSY)
+        {
+          /* From hal/hald/linux/addons/addon-storage.c: */
+          /* this means the disc is mounted or some other app,
+           * like a cd burner, has already opened O_EXCL */
+
+          /* HOWEVER, when starting hald, a disc may be
+           * mounted; so check /etc/mtab to see if it
+           * actually is mounted. If it is we retry to open
+           * without O_EXCL
+           */
+          if (is_mounted (device_file))
+            {
+              fd = open (device_file, O_RDONLY | O_NONBLOCK);
+            }
+        }
       if (fd != -1)
         {
           if (device->is_ide_cdrom)