Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262566AbVAUWUr (ORCPT ); Fri, 21 Jan 2005 17:20:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262564AbVAUWUL (ORCPT ); Fri, 21 Jan 2005 17:20:11 -0500 Received: from mail0.lsil.com ([147.145.40.20]:969 "EHLO mail0.lsil.com") by vger.kernel.org with ESMTP id S262566AbVAUWTS (ORCPT ); Fri, 21 Jan 2005 17:19:18 -0500 Message-ID: <0E3FA95632D6D047BA649F95DAB60E5705A70B74@exa-atlanta> From: "Mukker, Atul" To: "'James Bottomley'" , "'Matt Domsch'" Cc: "'Salyzyn, Mark'" , "Bagalkote, Sreenivas" , "'brking@us.ibm.com'" , "'Linux Kernel'" , "'SCSI Mailing List'" , "'bunk@fs.tum.de'" , "'Andrew Morton'" , "Ju, Seokmann" , "Doelfel, Hardy" , "Mukker, Atul" Subject: RE: How to add/drop SCSI drives from within the driver? Date: Fri, 21 Jan 2005 17:11:17 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2657.72) Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2744 Lines: 77 All right! The implementation is complete for this and the driver has thoroughly gone through testing. Everything looks good except for a minor glitch. After the new logical drives are created with "- - -" written to the scsi_host scan attribute, there is a highly noticeable delay before device names (e.g., sda) appears in the /dev directory. If the management application tried to access the device immediately after creating new, the access fails. Putting a 1 second delay helped, but of course this is not a deterministic solution. What are the other possibilities? Thanks -Atul Mukker LSI Logic > -----Original Message----- > From: James Bottomley [mailto:James.Bottomley@SteelEye.com] > Sent: Wednesday, December 15, 2004 1:49 PM > To: Matt Domsch > Cc: Salyzyn, Mark; Bagalkote, Sreenivas; brking@us.ibm.com; > Linux Kernel; SCSI Mailing List; bunk@fs.tum.de; Andrew > Morton; Ju, Seokmann; Doelfel, Hardy; Mukker, Atul > Subject: Re: How to add/drop SCSI drives from within the driver? > > On Wed, 2004-12-15 at 01:24 -0600, Matt Domsch wrote: > > James, I've been thinking about this a little more, and you > may be on > > to something here. Let each driver add files as such: > > > > /sys/class/scsi_host > > |-- host0 > > | |-- add_logical_drive > > | |-- remove_logical_drive > > | `-- rescan_logical_drive > > > > Then we can go 2 ways with this. > > 1) driver functions directly call scsi_add_device(), > > scsi_remove_device(), and something for rescan (option 2 > handles this > > one cleanly for us). ATM, megaraid_mbox doesn't implement a rescan > > function, so this point may be moot. > > > > 2) driver functions call a midlayer library function, which invokes > > /sbin/hotplug with appropriate data, and add a new /etc/hotplug.d > > helper app which would then write to these files: > > > > /sys/class/scsi_host > > |-- host0 > > | |-- scan > > /sys/devices/pci0000:0x/0000:0x:0x.0/host0 > > |-- 0:0:0:0 > > | |-- delete > > | |-- rescan > > > > to do likewise. > > I'll buy this (option 2).. it seems like a good way to export > the megaraid specific information and at the same time > integrate it more fully into the evolving hotplug infrastructure. > > James > > > - > 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/ > - 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/