[PATCH] fix block layer ioctl bug

If the blockdev doesn't implement BLKFLSBUF and returns -ENOTTY we should
still go ahead and perform the VFS-level sync.  We need to test for both
ENOTTY and EINVAL because some SCSI drivers incorrectly return EINVAL.
Signed-off-by: Ed L Cashin <ecashin@coraid.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/block/ioctl.c

@@ -194,7 +194,8 @@ int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
 			return -EACCES;
 		if (disk->fops->ioctl) {
 			ret = disk->fops->ioctl(inode, file, cmd, arg);
-			if (ret != -EINVAL)
+			/* -EINVAL to handle old uncorrected drivers */
+			if (ret != -EINVAL && ret != -ENOTTY)
 				return ret;
 		}
 		fsync_bdev(bdev);