From: Pavel Machek <pavel@suse.cz>
To: Steve Whitehouse <Steve@ChyGwyn.com>, andrea@suse.de
Cc: linux-kernel@vger.kernel.org
Subject: Re: NBD Hangs
Date: Sun, 25 Feb 2001 20:00:40 +0100 [thread overview]
Message-ID: <20010225200040.A3186@bug.ucw.cz> (raw)
In-Reply-To: <200102251217.MAA19785@gw.chygwyn.com>
In-Reply-To: <200102251217.MAA19785@gw.chygwyn.com>; from Steve Whitehouse on Sun, Feb 25, 2001 at 12:17:25PM +0000
Hi!
> I've been having some NBD hangs with the 2.4.2 kernel. It appears that
> block devices which don't use plugging will not have their request
> functions called when the request is queued. I propose the following
> patch to ll_rw_blk.c which seems to do the trick for me. Also I have
> done a small amount of tidying in nbd.c.
Thanx for nbd cleanups. All but two changes look good. Please submit
them to Linus and tell him I approved.
Pavel
> Btw, do you know what the deadlock problem is when plugging is enabled
> on nbd ? I had a good look through the code and did some tests and there
> certainly are problems with deadlocks with plugging enabled but I couldn't
> quite pin down the source. I guessed it might have something to do with
> blocking in the request function.
Sorry, no clues.
> diff -u -r linux-2.4.2-zc1/drivers/block/nbd.c linux/drivers/block/nbd.c
> --- linux-2.4.2-zc1/drivers/block/nbd.c Mon Oct 30 22:30:33 2000
> +++ linux/drivers/block/nbd.c Sun Feb 25 11:23:45 2001
> @@ -174,8 +175,11 @@
> }
>
> #define HARDFAIL( s ) { printk( KERN_ERR "NBD: " s "(result %d)\n", result ); lo->harderror = result; return NULL; }
> +
> +/*
> + * NULL returned = something went wrong, inform userspace
> + */
> struct request *nbd_read_stat(struct nbd_device *lo)
> - /* NULL returned = something went wrong, inform userspace */
> {
> int result;
> struct nbd_reply reply;
I do not like this one. Comment before function should describe what
it does.
> @@ -493,9 +493,7 @@
> MAJOR_NR);
> return -EIO;
> }
> -#ifdef MODULE
> printk("nbd: registered device at major %d\n", MAJOR_NR);
> -#endif
> blksize_size[MAJOR_NR] = nbd_blksizes;
> blk_size[MAJOR_NR] = nbd_sizes;
> blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), do_nbd_request);
Keep this ifdef module. I want module to say something, but not to
pollute kernel messages.
--
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
prev parent reply other threads:[~2001-02-25 19:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-02-25 12:17 NBD Hangs Steve Whitehouse
2001-02-25 19:00 ` Pavel Machek [this message]
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