From: James Bottomley <James.Bottomley@SteelEye.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Anton Blanchard <anton@samba.org>,
Dipankar Sarma <dipankar@in.ibm.com>,
SCSI Mailing List <linux-scsi@vger.kernel.org>,
Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [2.6.14-rc1] sym scsi boot hang
Date: Wed, 14 Sep 2005 16:35:13 -0400 [thread overview]
Message-ID: <1126730113.4825.12.camel@mulgrave> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0509141052410.5064-100000@iolanthe.rowland.org>
On Wed, 2005-09-14 at 11:49 -0400, Alan Stern wrote:
> (James, I see a possible problem with scsi_insert_special_req. It adds to
> the queue a request with REQ_DONTPREP set. How can such a request, with
> no associated scsi_cmnd, ever work? Also, won't scsi_end_request and
> __scsi_release_request end up putting the same scsi_command twice?)
It's a historical anomaly which will hopefully die when we finally
manage to get sg and st converted to the generic request infrastructure.
Then scsi_request can be killed and this along with it.
What used to happen (as the comment implies) is that drivers would
allocate a single request and then reuse it for multiple independent
commands. Since they weren't too picky about cleaning it up after each
use, we had to reset the DONTPREP flag to ensure each new invocation was
actually correctly prepared.
James
next prev parent reply other threads:[~2005-09-14 20:35 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-13 12:48 [2.6.14-rc1] sym scsi boot hang Dipankar Sarma
2005-09-13 13:17 ` Anton Blanchard
2005-09-13 14:29 ` Anton Blanchard
2005-09-13 16:35 ` James Bottomley
2005-09-13 16:47 ` Anton Blanchard
2005-09-13 17:32 ` James Bottomley
2005-09-13 17:13 ` Anton Blanchard
2005-09-13 17:33 ` Dipankar Sarma
2005-09-14 8:06 ` Anton Blanchard
2005-09-14 15:49 ` Alan Stern
2005-09-14 16:52 ` Mike Christie
2005-09-14 16:53 ` Mike Christie
2005-09-14 20:35 ` James Bottomley [this message]
2005-09-14 16:57 ` James Bottomley
2005-09-14 20:19 ` Alan Stern
2005-09-14 20:44 ` James Bottomley
2005-09-14 21:33 ` Alan Stern
2005-09-15 13:56 ` James Bottomley
2005-09-15 14:13 ` Alan Stern
2005-09-15 17:52 ` Alan Stern
2005-09-16 10:28 ` Anton Blanchard
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