RE: [PATCH 1/1] cciss: scsi error handling

From: Cameron, Steve
Date: Fri Nov 11 2005 - 14:38:36 EST


Jeff Garzik wrote:

> Two comments:
>
> 1) CONFIG_CISS_SCSI_TAPE should be CONFIG_CCISS_SCSI_TAPE, IMO
>
> 2) is any locking needed in your scsi eh reset handlers? recent
> kernels eliminate the lock that's been traditionally held around
> the handlers.

About the locking first,

So, there's one part that I was a little worried about, where
it does this in a couple places:

c = (ctlr_info_t **) &scsicmd->device->host->hostdata[0];

(gets our adapter structure by following pointers in the scsi
command)

So, if that pointer chain can change suddenly, then my code is bad.

Can doing "echo scsi remove-single-device . . . > /proc/scsi/scsi"
cause that pointer chain to break? I noticed I can yank a disk
out from under a mounted filesystem with
"echo scsi remove-single-device" It wasn't obvious to me whether
doing that would affect that pointer chain though, though I could
imagine it might.

Or am I barking up the wrong tree worrying about
the scsicmd->device->host->hostdata pointer chain
getting yanked out from under me?

Apart from possibly the two places where I do that,
I think it's ok.

About the CONFIG_CISS_SCSI_TAPE, we can change that, although
it's been that way for years, and was following the
BLK_CPQ_CISS_DA which was there since the drivers inception.
Does it unnecessarily break people's existing .config files?
(not badly of course.)

-- steve

-----Original Message-----
From: Jeff Garzik [mailto:jgarzik@xxxxxxxxx]
Sent: Fri 11/11/2005 5:36 AM
To: Miller, Mike (OS Dev)
Cc: axboe@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; Cameron, Steve
Subject: Re: [PATCH 1/1] cciss: scsi error handling

mike.miller@xxxxxx wrote:
> PATCH 1 of 1
>
> This patch adds SCSI error handling code to the SCSI portion
> of the cciss driver.
>
> Signed-off-by: Stephen M. Cameron <steve.cameron@xxxxxx>
> Acked-by: Mike Miller <mike.miller@xxxxxx>

> +#ifdef CONFIG_CISS_SCSI_TAPE

Two comments:

1) CONFIG_CISS_SCSI_TAPE should be CONFIG_CCISS_SCSI_TAPE, IMO

2) is any locking needed in your scsi eh reset handlers? recent kernels
eliminate the lock that's been traditionally held around the handlers.

Jeff



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