[PATCH] fix long delay for all devices in namedev

Now we only sleep if we can't find the device file, and we have
a hack to sleep for 1 second if we are on a partition.  This will be
removed when the libsysfs change gets made...

diff --git a/namedev.c b/namedev.c
index c77b0f8ef43a598d46b4437fef5e0e991ccde7d3..1e600bbe6d2b997112325133dbc03c980c2d12d7 100644 (file)
--- a/namedev.c
+++ b/namedev.c
@@ -624,57 +624,51 @@ static struct sysfs_device *get_sysfs_device(struct sysfs_class_device *class_de
        struct sysfs_device *sysfs_device;
        struct sysfs_class_device *class_dev_parent;
        int loop;
-
-       /* FIXME!!! */
-       /* This is needed here as we can easily out-race the placement of the
-        * device symlink by the kernel.  The call to sleep(1); will be removed
-        * once libsysfs can be queried for sysfs_get_classdev_device()
-        * multiple times and have it return the proper information when the
-        * class device really shows up.  For now, we live with the time
-        * delay...
+       char filename[SYSFS_PATH_MAX + 6];
+       int retval;
+       char *temp;
+       int partition = 0;
+
+       /* Figure out where the device symlink is at.  For char devices this will
+        * always be in the class_dev->path.  But for block devices, it's different.
+        * The main block device will have the device symlink in it's path, but
+        * all partitions have the symlink in its parent directory.
+        * But we need to watch out for block devices that do not have parents, yet
+        * look like a partition (fd0, loop0, etc.)  They all do not have a device
+        * symlink yet.  We do sit and spin on waiting for them right now, we should
+        * possibly have a whitelist for these devices here...
         */
-       sleep(1);
+       strcpy(filename, class_dev->path);
+       dbg("filename = %s", filename);
+       if (strcmp(class_dev->classname, SYSFS_BLOCK_NAME) == 0) {
+               if (isdigit(class_dev->path[strlen(class_dev->path)-1])) {
+                       temp = strrchr(filename, '/');
+                       if (temp) {
+                               partition = 1;
+                               *temp = 0x00;
+                               char *temp2 = strrchr(filename, '/');
+                               dbg("temp2 = %s", temp2);
+                               if (temp2 && (strcmp(temp2, "/block") == 0)) {
+                                       /* oops, we have no parent block device, so go back to original directory */
+                                       strcpy(filename, class_dev->path);
+                                       partition = 0;
+                               }
+                       }
+               }
+       }
+       strcat(filename, "/device");
 
-#if 0  /* FIXME
-          Something like this could also work, but for some reason doesn't,
-          I also tried just stat() on the device symlink, but that still
-          has nasty races, I'm probably doing something stupid... :( */
-       loop = 10;
+       loop = 2;
        while (loop--) {
                struct stat buf;
-               int retval;
-               char filename[SYSFS_PATH_MAX + 6];
-
-               strcpy(filename, class_dev->path);
-               strcat(filename, "/device");
                dbg("looking for '%s'", filename);
                retval = stat(filename, &buf);
                if (!retval)
                        break;
-
-               /* bah, let's go backwards up a level to see if the device is there,
-                * as block partitions don't point to the physical device.  Need to fix that
-                * up in the kernel...
-                */
-               if (strcmp(class_dev->classname, SYSFS_BLOCK_NAME) == 0) {
-                       if (isdigit(class_dev->path[strlen(class_dev->path)-1])) {
-                               class_dev_parent = sysfs_get_classdev_parent(class_dev);
-                               if (class_dev_parent == NULL) {
-                                       dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name);
-                               } else {
-                                       strcpy(filename, class_dev_parent->path);
-                                       strcat(filename, "/device");
-                                       dbg("looking for '%s'", filename);
-                                       retval = stat(filename, &buf);
-                                       if (!retval)
-                                               break;
-                               }
-                       }
-               }
                /* sleep to give the kernel a chance to create the device file */
                sleep(1);
        }
-#endif
+
        loop = 1;       /* FIXME put a real value in here for when everything is fixed... */
        while (loop--) {
                /* find the sysfs_device for this class device */
@@ -683,28 +677,28 @@ static struct sysfs_device *get_sysfs_device(struct sysfs_class_device *class_de
                if (sysfs_device != NULL)
                        goto exit;
 
-               /* bah, let's go backwards up a level to see if the device is there,
-                * as block partitions don't point to the physical device.  Need to fix that
-                * up in the kernel...
-                */
-               if (strcmp(class_dev->classname, SYSFS_BLOCK_NAME) == 0) {
-                       dbg("looking at block device");
-                       if (isdigit(class_dev->path[strlen(class_dev->path)-1])) {
-                               dbg("really is a partition");
-                               class_dev_parent = sysfs_get_classdev_parent(class_dev);
-                               if (class_dev_parent == NULL) {
-                                       dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name);
-                               } else {
-                                       dbg("class_dev_parent->name='%s'", class_dev_parent->name);
-                                       sysfs_device = sysfs_get_classdev_device(class_dev_parent);
-                                       if (sysfs_device != NULL)
-                                               goto exit;
-                               }
+               /* if it's a partition, we need to get the parent device */
+               if (partition) {
+                       /* FIXME  HACK HACK HACK HACK
+                        * for some reason partitions need this extra sleep here, in order
+                        * to wait for the device properly.  Once the libsysfs code is
+                        * fixed properly, this sleep should go away, and we can just loop above.
+                        */
+                       sleep(1);
+                       dbg("really is a partition");
+                       class_dev_parent = sysfs_get_classdev_parent(class_dev);
+                       if (class_dev_parent == NULL) {
+                               dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name);
+                       } else {
+                               dbg("class_dev_parent->name='%s'", class_dev_parent->name);
+                               sysfs_device = sysfs_get_classdev_device(class_dev_parent);
+                               if (sysfs_device != NULL)
+                                       goto exit;
                        }
                }
                /* sleep to give the kernel a chance to create the link */
-               sleep(1);
-
+               /* FIXME remove comment...
+               sleep(1); */
        }
        dbg("Timed out waiting for device symlink, continuing on anyway...");
 exit: