* [PATCH] virtio_scsi: check on resp->sense_len instead of 'sense_buffer'
@ 2014-07-18 14:57 Ming Lei
2014-07-18 15:00 ` Paolo Bonzini
0 siblings, 1 reply; 3+ messages in thread
From: Ming Lei @ 2014-07-18 14:57 UTC (permalink / raw)
To: James E.J. Bottomley, Paolo Bonzini
Cc: linux-scsi, Christoph Hellwig, Ming Lei
The 'sense_buffer' of 'struct scsi_cmnd' is always true, but
resp->sense_len is only set if there is sense available.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
---
drivers/scsi/virtio_scsi.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index eee1bc0..4d2d3b2 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -194,11 +194,10 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
}
WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE);
- if (sc->sense_buffer) {
+ if (resp->sense_len) {
memcpy(sc->sense_buffer, resp->sense,
min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE));
- if (resp->sense_len)
- set_driver_byte(sc, DRIVER_SENSE);
+ set_driver_byte(sc, DRIVER_SENSE);
}
sc->scsi_done(sc);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] virtio_scsi: check on resp->sense_len instead of 'sense_buffer'
2014-07-18 14:57 [PATCH] virtio_scsi: check on resp->sense_len instead of 'sense_buffer' Ming Lei
@ 2014-07-18 15:00 ` Paolo Bonzini
2014-07-18 15:09 ` Ming Lei
0 siblings, 1 reply; 3+ messages in thread
From: Paolo Bonzini @ 2014-07-18 15:00 UTC (permalink / raw)
To: Ming Lei, James E.J. Bottomley; +Cc: linux-scsi, Christoph Hellwig
Il 18/07/2014 16:57, Ming Lei ha scritto:
> - if (sc->sense_buffer) {
> + if (resp->sense_len) {
In the (unlikely) case that sc->sense_buffer == NULL, you'd pass a NULL
to memcpy.
If you want, you can change this if to
if (sc->sense_buffer && resp->sense_len)
but frankly it seems like slightly pointless churn to me.
Paolo
> memcpy(sc->sense_buffer, resp->sense,
> min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE));
> - if (resp->sense_len)
> - set_driver_byte(sc, DRIVER_SENSE);
> + set_driver_byte(sc, DRIVER_SENSE);
> }
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] virtio_scsi: check on resp->sense_len instead of 'sense_buffer'
2014-07-18 15:00 ` Paolo Bonzini
@ 2014-07-18 15:09 ` Ming Lei
0 siblings, 0 replies; 3+ messages in thread
From: Ming Lei @ 2014-07-18 15:09 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: James E.J. Bottomley, Linux SCSI List, Christoph Hellwig
On Fri, Jul 18, 2014 at 11:00 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Il 18/07/2014 16:57, Ming Lei ha scritto:
>> - if (sc->sense_buffer) {
>> + if (resp->sense_len) {
>
> In the (unlikely) case that sc->sense_buffer == NULL, you'd pass a NULL
> to memcpy.
Every valid scsi_cmnd should have non NULL sc->sense_buffer, please
see scsi_host_alloc_command().
Thanks,
--
Ming Lei
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-07-18 15:09 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2014-07-18 14:57 [PATCH] virtio_scsi: check on resp->sense_len instead of 'sense_buffer' Ming Lei
2014-07-18 15:00 ` Paolo Bonzini
2014-07-18 15:09 ` Ming Lei
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