libdrm: Make chown check for return value

If call was interrupted by signal we have to make call again.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

diff --git a/libdrm/xf86drm.c b/libdrm/xf86drm.c
index 1a5cee4..26dd812 100644 (file)
--- a/libdrm/xf86drm.c
+++ b/libdrm/xf86drm.c
@@ -270,6 +270,36 @@ static int drmMatchBusID(const char *id1, const char *id2)
 }
 
 /**
+ * Handles error checking for chown call.
+ *
+ * \param path to file.
+ * \param id of the new owner.
+ * \param id of the new group.
+ *
+ * \return zero if success or -1 if failure.
+ *
+ * \internal
+ * Checks for failure. If failure was caused by signal call chown again.
+ * If any other failure happened then it will output error mesage using
+ * drmMsg() call.
+ */
+static int chown_check_return(const char *path, uid_t owner, gid_t group)
+{
+       int rv;
+
+       do {
+               rv = chown(path, owner, group);
+       } while (rv != 0 && errno == EINTR);
+
+       if (rv == 0)
+               return 0;
+
+       drmMsg("Failed to change owner or group for file %s! %d: %s\n",
+                       path, errno, strerror(errno));
+       return -1;
+}
+
+/**
  * Open the DRM device, creating it if necessary.
  *
  * \param dev major and minor numbers of the device.
@@ -307,7 +337,7 @@ static int drmOpenDevice(long dev, int minor, int type)
        if (!isroot)
            return DRM_ERR_NOT_ROOT;
        mkdir(DRM_DIR_NAME, DRM_DEV_DIRMODE);
-       chown(DRM_DIR_NAME, 0, 0); /* root:root */
+       chown_check_return(DRM_DIR_NAME, 0, 0); /* root:root */
        chmod(DRM_DIR_NAME, DRM_DEV_DIRMODE);
     }
 
@@ -320,7 +350,7 @@ static int drmOpenDevice(long dev, int minor, int type)
     }
 
     if (drm_server_info) {
-       chown(buf, user, group);
+       chown_check_return(buf, user, group);
        chmod(buf, devmode);
     }
 #else
@@ -363,7 +393,7 @@ wait_for_udev:
        remove(buf);
        mknod(buf, S_IFCHR | devmode, dev);
        if (drm_server_info) {
-           chown(buf, user, group);
+           chown_check_return(buf, user, group);
            chmod(buf, devmode);
        }
     }