> On May 16, 2017, at 10:00 AM, Benjamin Block <bbl...@linux.vnet.ibm.com>
> wrote:
>
> Hello,
>
> On Wed, May 03, 2017 at 05:50:13PM -0700, Song Liu wrote:
>> This patch adds capability for SCSI layer to generate uevent for SCSI
>> sense code. The feature is gated by CONFIG_SCSI_SENSE_UEVENT.
>>
>> We can configure which sense keys generate uevent for each device
>> through sysfs entry sense_event_filter. For example, the following
>> enables uevent for MEDIUM_ERROR (0x03) and HARDWARE_ERROR (0x04)
>> on scsi drive sdc:
>>
>> echo 0x000c > /sys/block/sdc/device/sense_event_filter
>>
>
> I know its an RFC, but the user-interface definitely needs better
> documentation. You also don't mention the 'wildcard' you document in the
> code below.
>
> Would there be any public tooling for this, when it gets in?
>
> There is already some events we can generate.. for example when the
> host-mapping changed, but I am not aware of any tooling that would ever
> make use of them (although, this probably would even be vert useful).
> And in the end that seems like dead-code for me. But maybe thats just me
> not knowing the tooling.
Hi Benjamin,
Thanks for these feedbacks. I will incorporate them into next version.
In term of tooling, we will open source useful tools we build to consume
these events.
>>
>> Here is an example output captured by udevadm:
>>
>> KERNEL[1214.945358] change /devices/pci0000:00/XXXXXXX
>> ACTION=change
>> DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/host6/XXXXXXX
>> DEVTYPE=scsi_device
>> DRIVER=sd
>> LBA=0
>> MODALIAS=scsi:t-0x00
>> SDEV_UA=SCSI_SENSE
>> SENSE_CODE=3/11/14
>> SEQNUM=4536
>> SIZE=4096
>> SUBSYSTEM=scsi
>>
>> Signed-off-by: Song Liu <songliubrav...@fb.com>
>> ---
>> drivers/scsi/Kconfig | 14 +++++++++++
>> drivers/scsi/scsi_error.c | 26 ++++++++++++++++++++
>> drivers/scsi/scsi_lib.c | 27 +++++++++++++++++++--
>> drivers/scsi/scsi_sysfs.c | 60
>> ++++++++++++++++++++++++++++++++++++++++++++++
>> include/scsi/scsi_device.h | 26 +++++++++++++++++++-
>> 5 files changed, 150 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
>> index 3c52867..4f7f211 100644
>> --- a/drivers/scsi/Kconfig
>> +++ b/drivers/scsi/Kconfig
>> @@ -237,6 +237,20 @@ config SCSI_LOGGING
>> there should be no noticeable performance impact as long as you have
>> logging turned off.
>>
>> +config SCSI_SENSE_UEVENT
>> + bool "SCSI sense code logging"
>> + depends on SCSI
>> + default n
>> + ---help---
>> + This turns on uevent for SCSI sense code.
>> +
>> + You can configure which sense keys generate uevent for each device
>> + through sysfs entry sense_event_filter. For example, the following
>> + enables uevent for MEDIUM_ERROR (0x03) and HARDWARE_ERROR (0x04)
>> + on scsi drive sdc:
>> +
>> + echo 0x000c > /sys/block/sdc/device/sense_event_filter
>> +
>> config SCSI_SCAN_ASYNC
>> bool "Asynchronous SCSI scanning"
>> depends on SCSI
>> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
>> index d70c67c..eda150e 100644
>> --- a/drivers/scsi/scsi_error.c
>> +++ b/drivers/scsi/scsi_error.c
>> @@ -426,6 +426,31 @@ static void scsi_report_sense(struct scsi_device *sdev,
>> }
>> }
>>
>> +/*
>> + * generate uevent when receiving sense code from device
>> + */
>> +static void scsi_send_sense_uevent(struct scsi_device *sdev,
>> + struct scsi_cmnd *scmd,
>> + struct scsi_sense_hdr *sshdr)
>> +{
>> +#ifdef CONFIG_SCSI_SENSE_UEVENT
>> + struct scsi_event *evt;
>> +
>> + if (!test_bit(sshdr->sense_key & 0xf,
>> + &sdev->sense_event_filter))
>> + return;
>> + evt = sdev_evt_alloc(SDEV_EVT_SCSI_SENSE, GFP_ATOMIC);
>> + if (!evt)
>> + return;
>> +
>> + evt->sense_evt_data.lba = scsi_get_lba(scmd);
>> + evt->sense_evt_data.size = blk_rq_bytes(scmd->request);
>> + memcpy(&evt->sense_evt_data.sshdr, sshdr,
>> + sizeof(struct scsi_sense_hdr));
>> + sdev_evt_send(sdev, evt);
>> +#endif
>> +}
>> +
>
> So when I turn this CONFIG_ off, do I get all kinds of warning about
> unused variables?
I don't get any warning at this time. I will keep testing w/ and w/o
the config enabled.
Thanks,
Song
