From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH 2/3 ver2] block layer extended-cdb support Date: Sun, 13 Apr 2008 09:07:55 -0500 Message-ID: <1208095676.4707.6.camel@localhost.localdomain> References: <47F522A6.3080806@panasas.com> <20080404114614.GJ29686@kernel.dk> <47F89948.9060503@panasas.com> <20080412145152C.tomof@acm.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from accolon.hansenpartnership.com ([76.243.235.52]:37803 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757447AbYDMOIF (ORCPT ); Sun, 13 Apr 2008 10:08:05 -0400 In-Reply-To: <20080412145152C.tomof@acm.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: FUJITA Tomonori Cc: bharrosh@panasas.com, jens.axboe@oracle.com, hch@infradead.org, linux-scsi@vger.kernel.org, akpm@linux-foundation.org On Sat, 2008-04-12 at 14:52 +0900, FUJITA Tomonori wrote: > bsg are created only for scsi devices (and scsi objects like sas host) > now. Are there other means to send commands except for ioctl? Right now they are ... but the design was to allow for arbitrary packet commands (like the frame in/frame out type that SMP needs), so the anticipation is that it will be usable by arbitrary packet commands for any block conforming device, examples of which would be ide taskfiles, raid firmware commands and any other weirder native protocols. On the other hand, this is future work and won't depend on the legacy 16 byte cmd size. The only block device I know that implements SG_IO is cciss, so perhaps there's no need to support a legacy mode at all for large packet commands. James