From: Anton Vorontsov <cbou@mail.ru>

Because add_disk() getting driverfs_dev twice but putting it only once,
ide-{disk,cd,floppy} should put_device() themselfs. This is workaround
for the bug found in genhd, which causes deadlock in ide_unregister()
at wait_for_completion(&drive->gendev_rel_comp) after
device_unregister(&drive->gendev). That happens by reason of
ide-probe.c:drive_release_dev() not called because of driverfs_dev
(which is drive->gendev) still referenced by add_disk().

Index: drivers/ide/ide-cd.c
===================================================================
RCS file: /cvs/linux/kernel26/drivers/ide/ide-cd.c,v
retrieving revision 1.21
diff -u -p -b -B -r1.21 ide-cd.c
--- drivers/ide/ide-cd.c	23 Aug 2006 18:35:05 -0000	1.21
+++ drivers/ide/ide-cd.c	18 Oct 2006 21:18:52 -0000
@@ -3240,6 +3240,7 @@ static void ide_cd_release(struct kref *
 	blk_queue_prep_rq(drive->queue, NULL);
 	g->private_data = NULL;
 	put_disk(g);
+	put_device(&drive->gendev);
 	kfree(info);
 }
 
Index: drivers/ide/ide-disk.c
===================================================================
RCS file: /cvs/linux/kernel26/drivers/ide/ide-disk.c,v
retrieving revision 1.19
diff -u -p -b -B -r1.19 ide-disk.c
--- drivers/ide/ide-disk.c	23 Aug 2006 18:35:05 -0000	1.19
+++ drivers/ide/ide-disk.c	18 Oct 2006 21:18:52 -0000
@@ -1021,6 +1021,7 @@ static void ide_disk_release(struct kref
 	drive->devfs_name[0] = '\0';
 	g->private_data = NULL;
 	put_disk(g);
+	put_device(&drive->gendev);
 	kfree(idkp);
 }
 
Index: drivers/ide/ide-floppy.c
===================================================================
RCS file: /cvs/linux/kernel26/drivers/ide/ide-floppy.c,v
retrieving revision 1.16
diff -u -p -b -B -r1.16 ide-floppy.c
--- drivers/ide/ide-floppy.c	23 Aug 2006 18:35:05 -0000	1.16
+++ drivers/ide/ide-floppy.c	18 Oct 2006 21:18:52 -0000
@@ -1893,6 +1893,7 @@ static void ide_floppy_release(struct kr
 	drive->driver_data = NULL;
 	g->private_data = NULL;
 	put_disk(g);
+	put_device(&drive->gendev);
 	kfree(floppy);
 }