Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761338AbXEJMNZ (ORCPT ); Thu, 10 May 2007 08:13:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759593AbXEJMNE (ORCPT ); Thu, 10 May 2007 08:13:04 -0400 Received: from vervifontaine.sonytel.be ([80.88.33.193]:36159 "EHLO vervifontaine.sonycom.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1759194AbXEJMNB (ORCPT ); Thu, 10 May 2007 08:13:01 -0400 Date: Thu, 10 May 2007 14:12:59 +0200 (CEST) From: Geert Uytterhoeven To: Linux Kernel Development , linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org Subject: HDIO_DRIVE_CMD and hdparm Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2326 Lines: 83 Hi, `hdparm -t' uses HDIO_DRIVE_CMD(null) to flush the disk's buffer. When using it on my own block device (the new PS3 disk storage driver), hdparm gives the following error message: | HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device When using it on an ATA or SCSI device, no such error message is printed. According to the hdparm sources, hdparm expects the HDIO_DRIVE_CMD(null) ioctl to either succeed, or to fail with errno EINVAL. Apparently handling of ioctls is different for the different device types: - ATA/SATA handle HDIO_DRIVE_CMD(null) (and a few other variants) => fine for hdparm - SCSI doesn't handle HDIO_DRIVE_CMD(null), and returns EINVAL => fine for hdparm - If a block device doesn't support the ioctl, blkdev_driver_ioctl() returns ENOTTY => hdparm error message Which one is correct? - blkdev_ioctl()/blkdev_driver_ioctl() return -ENOTTY - scsi_cmd_ioctl() returns -ENOTTY - scsi_ioctl() returns -EINVAL - cdrom_ioctl() returns -ENOSYS to mean not handled, continue - some block layer routines return -ENOIOCTLCMD to mean not handled, continue This causes constructs with different tests like e.g.: sr_block_ioctl() { ... ret = cdrom_ioctl(...); if (ret != -ENOSYS) return ret; ... return scsi_ioctl(...); } cdrom_ioctl() { ... ret = scsi_cmd_ioctl(...); if (ret != -ENOTTY) return ret; ... return -ENOSYS; } blkdev_ioctl() { ... ret = blkdev_locked_ioctl(...); ... if (ret != -ENOIOCTLCMD) return ret; return blkdev_driver_ioctl(...); } My questions: 1. Does any of these have to be fixed? 2. Shall I add a dummy HDIO_DRIVE_CMD(null) handler to my block device to return -EINVAL? 3. Shall I just ignore the hdparm error message? Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- Sony Network and Software Technology Center Europe (NSCE) Geert.Uytterhoeven@sonycom.com ------- The Corporate Village, Da Vincilaan 7-D1 Voice +32-2-7008453 Fax +32-2-7008622 ---------------- B-1935 Zaventem, Belgium - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/