Re: [PATCH RFC v3 00/41] scsi: enable reserved commands for LLDDs

From: Hannes Reinecke <hare@suse.de>
To: John Garry <john.garry@huawei.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>,
	James Bottomley <james.bottomley@hansenpartnership.com>,
	Ming Lei <ming.lei@redhat.com>,
	Bart van Assche <bvanassche@acm.org>,
	"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>
Subject: Re: [PATCH RFC v3 00/41] scsi: enable reserved commands for LLDDs
Date: Sat, 2 May 2020 14:23:46 +0200	[thread overview]
Message-ID: <9489fadc-3d80-1ea2-057c-8cef37684fe1@suse.de> (raw)
In-Reply-To: <55c7aaf0-6863-a3ac-9e22-31eec1a359e4@huawei.com>

On 5/1/20 2:01 PM, John Garry wrote:
> On 30/04/2020 14:18, Hannes Reinecke wrote:
> 
> Thanks for this.
> 
>> Conversion of the SAS drivers hisi_sas, pm8001, and mv_sas are
>> compile tested only; I'd be grateful if someone could give
>> these patches a spin on that hardware, too.
> 
> So after some build fixups, I get this a NULL pointer deref:
> 
> [ 5.565899]  sas_find_dev_by_rphy+0x3c/0x104
> [ 5.570182]  sas_target_alloc+0x18/0x84
> [ 5.574029]  scsi_alloc_target+0x20c/0x304
> [ 5.578136]  scsi_get_virtual_dev+0x44/0xec
> [ 5.582331]  sas_register_ha+0xd0/0x258
> [ 5.586178]  hisi_sas_probe+0x2ec/0x36c
> [ 5.590024]  hisi_sas_v2_probe+0x34/0x64
> [ 5.593958]  platform_drv_probe+0x4c/0xa0
> [ 5.597978]  really_probe+0xd8/0x334
> [ 5.601561]  driver_probe_device+0x58/0xe8
> [ 5.605669]  device_driver_attach+0x68/0x70
> [ 5.609864]  __driver_attach+0x9c/0xf8
> [ 5.613622]  bus_for_each_dev+0x50/0xa0
> [ 5.617468]  driver_attach+0x20/0x28
> [ 5.621051]  bus_add_driver+0x148/0x1fc
> [ 5.624897]  driver_register+0x6c/0x124
> [ 5.628742]  __platform_driver_register+0x48/0x50
> [ 5.633463]  hisi_sas_v2_driver_init+0x18/0x20
> [ 5.637921]  do_one_initcall+0x50/0x194
> [ 5.641767]  kernel_init_freeable+0x1e4/0x24c
> 
> And so we need this change:
> 
> commit 51f607bf91853026af102367d9e6666605cdec61 (HEAD)
> Author: John Garry <john.garry@huawei.com>
> Date:   Fri May 1 12:30:32 2020 +0100
> 
>      scsi: libsas: Don't attempt to find scsi host rphy in target alloc
> 
>      It doesn't have one.
> 
>      Signed-off-by: John Garry <john.garry@huawei.com>
> 
> diff --git a/drivers/scsi/libsas/sas_scsi_host.c 
> b/drivers/scsi/libsas/sas_scsi_host.c
> index 585e0df5fce2..f1a823d51044 100644
> --- a/drivers/scsi/libsas/sas_scsi_host.c
> +++ b/drivers/scsi/libsas/sas_scsi_host.c
> @@ -822,8 +825,15 @@ struct domain_device *sas_find_dev_by_rphy(struct 
> sas_rphy *rphy)
> 
>   int sas_target_alloc(struct scsi_target *starget)
>   {
> -       struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
> -       struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
> +       struct device *parent = starget->dev.parent;
> +       struct sas_rphy *rphy;
> +       struct domain_device *found_dev;
> +
> +       if (scsi_is_host_device(parent))
> +               return 0;
> +
> +       rphy = dev_to_rphy(parent);
> +       found_dev = sas_find_dev_by_rphy(rphy);
> 
> 
Thank you, will be including it in the next round.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
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