RE: [PATCH] storvsc: add more logging for error and warning messages

Long Li
2015-12-04T02:55:45Z

Thanks Joe.

I'll send out another patch.

> -----Original Message-----
> From: Joe Perches [mailto:joe@perches.com]
> Sent: Thursday, December 3, 2015 6:28 PM
> To: Long Li <longli@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
> Haiyang Zhang <haiyangz@microsoft.com>; James E.J. Bottomley
> <JBottomley@odin.com>
> Cc: devel@linuxdriverproject.org; linux-scsi@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH] storvsc: add more logging for error and warning
> messages
>
> On Thu, 2015-12-03 at 19:47 -0800, Long Li wrote:
> > Introduce a logging level for storvsc to log certain error/warning
> > messages. Those messages are helpful in some environments, e.g.
> > Microsoft Azure, for customer support and troubleshooting purposes.
> []
> > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
> []
> > +static inline bool do_logging(int level) {
> > + return (logging_level >= level) ? true : false;
>
> The ternary is not necessary
>
> return logging_level >= level;
>
> is enough
>
> > +}
> > +
> > +
> >  struct vmscsi_win8_extension {
> >   /*
> >    * The following were added in Windows 8 @@ -1183,7 +1198,7 @@
> > static void storvsc_command_completion(struct storvsc_cmd_request
> > *cmd_request)
> >
> >   scmnd->result = vm_srb->scsi_status;
> >
> > - if (scmnd->result) {
> > + if (scmnd->result && do_logging(STORVSC_LOGGING_ERROR)) {
> >   if (scsi_normalize_sense(scmnd->sense_buffer,
> >   SCSI_SENSE_BUFFERSIZE, &sense_hdr))
> >   scsi_print_sense_hdr(scmnd->device, "storvsc",
>
> Is it appropriate to make this scsi_normalize_sense call conditional on
> do_logging here?
>
> > @@ -1239,12 +1254,25 @@ static void storvsc_on_io_completion(struct
> hv_device *device,
> >   stor_pkt->vm_srb.sense_info_length =
> >   vstor_packet->vm_srb.sense_info_length;
> >
> > + if (vstor_packet->vm_srb.scsi_status != 0 ||
> > + vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
> > + if (do_logging(STORVSC_LOGGING_WARN))
> > + dev_warn(&device->device,
> > + "cmd 0x%x scsi status 0x%x srb status
> 0x%x\n",
> > + stor_pkt->vm_srb.cdb[0],
> > + vstor_packet->vm_srb.scsi_status,
> > + vstor_packet->vm_srb.srb_status);
>
> It might make some sense to use another macro indirection like
>
> #define svc_log_warn(dev, level, fmt, ...) \
> do { \
> if (do_logging(STORSVC_LOGGING_##level) \
> dev_warn(&(dev)->device, fmt, ##__VA_ARGS__); \
> } while (0)
>
> So a use could be:
>
> if (vstore_packet...)
> svc_log_warn(device, WARN, ...);
>
> >