From: Jens Axboe <axboe@suse.de>
To: Matthew Wilcox <willy@debian.org>
Cc: Steven Dake <sdake@mvista.com>,
linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: kernel BUG using multipath on 2.6.0-test5
Date: Fri, 26 Sep 2003 14:26:46 +0200 [thread overview]
Message-ID: <20030926122646.GA15415@suse.de> (raw)
In-Reply-To: <20030926121703.GG24824@parcelfarce.linux.theplanet.co.uk>
On Fri, Sep 26 2003, Matthew Wilcox wrote:
> On Thu, Sep 25, 2003 at 06:57:15PM -0700, Steven Dake wrote:
> > kernel BUG at drivers/scsi/scsi_lib.c:544!
>
> BUG_ON(!cmd->use_sg);
>
> > [<c01f631d>] scsi_init_io+0x7a/0x13d
>
> static int scsi_init_io(struct scsi_cmnd *cmd)
> struct request *req = cmd->request;
> cmd->use_sg = req->nr_phys_segments;
> sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
>
> > [<c01f6455>] scsi_prep_fn+0x75/0x171
>
> static int scsi_prep_fn(struct request_queue *q, struct request *req)
> struct scsi_cmnd *cmd;
> cmd->request = req;
> ret = scsi_init_io(cmd);
>
> .. this is getting outside my area of confidence. Ask axboe why we might
> get a zero nr_phys_segments request passed in.
Looks like an mp bug. I'd suggest adding something ala
if (!rq->nr_phys_segments || !rq->nr_hw_segments) {
blk_dump_rq_flags(req, "scsi_init_io");
return BLKPREP_KILL;
}
inside the first
} else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
drivers/scsi/scsi_lib.c:scsi_prep_fn(). That will show the state of such
a buggy request. I'm pretty sure this is an mp bug though.
--
Jens Axboe
next prev parent reply other threads:[~2003-09-26 12:26 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-26 1:57 kernel BUG using multipath on 2.6.0-test5 Steven Dake
2003-09-26 12:17 ` Matthew Wilcox
2003-09-26 12:26 ` Jens Axboe [this message]
2003-09-26 20:14 ` Steven Dake
2003-09-27 0:34 ` [PATCH] fixes defect with " Steven Dake
2003-09-27 8:33 ` Jens Axboe
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