From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Ravish Tayal <ravish.tayal@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: generic_make_request fucntion for scsi_disk
Date: Sat, 20 Jun 2009 09:20:40 -0500 [thread overview]
Message-ID: <1245507640.4255.6.camel@mulgrave.site> (raw)
In-Reply-To: <e42309110906200705j6a731ecay204969f639af5330@mail.gmail.com>
On Sat, 2009-06-20 at 19:35 +0530, Ravish Tayal wrote:
> I am debugging Filesystem code for USB mass storage devices. I need
> help to figure out after generic_make_request how the request is
> placed to scsi disk (sd) requeset queue and than how sd qeueuecommand
> to usb_storeage thread. (in which context, is it system call context)
requests out of the lower end of block come from the elevators. The
elevators can operate in a variety of contexts: user, kernel thread or
softirq depending on state.
The mechanism for queueing to the USB thread is in
scsiglue.c:queuecommand() it's basically a simple single command
consumer model: fill in slot and wake thread.
James
next prev parent reply other threads:[~2009-06-20 14:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-20 14:05 generic_make_request fucntion for scsi_disk Ravish Tayal
2009-06-20 14:20 ` James Bottomley [this message]
[not found] ` <e42309110906200741x28595685jf56cd505d01cc795@mail.gmail.com>
2009-06-20 14:53 ` James Bottomley
[not found] ` <e42309110906200705j6a731ecay204969f639af5330-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-20 14:39 ` Alan Stern
[not found] <e42309110906200746u441b82acvec4e3e513253af0@mail.gmail.com>
2009-06-20 14:56 ` Alan Stern
2009-06-20 15:33 ` Ravish Tayal
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