[PATCH] scsi: don't look for NULL devices handlers by name

[PATCH] scsi: don't look for NULL devices handlers by name

[Johannes Thumshirn]

Currently scsi_dh_lookup() doesn't check for NULL as a device
name. This combined with nvme over dm-mapth results in the following
messages emitted by device-mapper:

 device-mapper: multipath: Could not failover device 259:67: Handler scsi_dh_(null) error 14.

Let scsi_dh_lookup() fail fast on NULL names.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/scsi/scsi_dh.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c
index b88b5dbbc444..188f30572aa1 100644
--- a/drivers/scsi/scsi_dh.c
+++ b/drivers/scsi/scsi_dh.c
@@ -112,6 +112,9 @@ static struct scsi_device_handler *scsi_dh_lookup(const char *name)
 {
 	struct scsi_device_handler *dh;
 
+	if (!name || strlen(name) == 0)
+		return NULL;
+
 	dh = __scsi_dh_lookup(name);
 	if (!dh) {
 		request_module("scsi_dh_%s", name);
-- 
2.13.6

Re: [PATCH] scsi: don't look for NULL devices handlers by name

[Hannes Reinecke]

On Fri, 23 Mar 2018 14:37:05 +0100
Johannes Thumshirn <jthumshirn@suse.de> wrote:

> Currently scsi_dh_lookup() doesn't check for NULL as a device
> name. This combined with nvme over dm-mapth results in the following
> messages emitted by device-mapper:
> 
>  device-mapper: multipath: Could not failover device 259:67: Handler
> scsi_dh_(null) error 14.
> 
> Let scsi_dh_lookup() fail fast on NULL names.
> 
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> ---
>  drivers/scsi/scsi_dh.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c
> index b88b5dbbc444..188f30572aa1 100644
> --- a/drivers/scsi/scsi_dh.c
> +++ b/drivers/scsi/scsi_dh.c
> @@ -112,6 +112,9 @@ static struct scsi_device_handler
> *scsi_dh_lookup(const char *name) {
>  	struct scsi_device_handler *dh;
>  
> +	if (!name || strlen(name) == 0)
> +		return NULL;
> +
>  	dh = __scsi_dh_lookup(name);
>  	if (!dh) {
>  		request_module("scsi_dh_%s", name);

Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes

Re: [PATCH] scsi: don't look for NULL devices handlers by name

[Bart Van Assche]

On Fri, 2018-03-23 at 14:37 +0100, Johannes Thumshirn wrote:
> Currently scsi_dh_lookup() doesn't check for NULL as a device
> name. This combined with nvme over dm-mapth results in the following
> messages emitted by device-mapper:
> 
>  device-mapper: multipath: Could not failover device 259:67: Handler scsi_dh_(null) error 14.
> 
> Let scsi_dh_lookup() fail fast on NULL names.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>

Re: [PATCH] scsi: don't look for NULL devices handlers by name

[Martin K. Petersen]

Johannes,

> Currently scsi_dh_lookup() doesn't check for NULL as a device
> name. This combined with nvme over dm-mapth results in the following
> messages emitted by device-mapper:

Applied to 4.16/scsi-fixes. Thank you!

-- 
Martin K. Petersen	Oracle Linux Engineering