storvsc: add logging for error/warning messages

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.

Signed-off-by: Long Li <longli@microsoft.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 3fba42ad9fb8aee55d5015167a9cb9ad601fb1a7..c41f6748823a7658050fb369178f3cadb4778b89 100644 (file)
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -164,6 +164,26 @@ static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 */
 static int vmstor_proto_version;
 
+#define STORVSC_LOGGING_NONE   0
+#define STORVSC_LOGGING_ERROR  1
+#define STORVSC_LOGGING_WARN   2
+
+static int logging_level = STORVSC_LOGGING_ERROR;
+module_param(logging_level, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(logging_level,
+       "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
+
+static inline bool do_logging(int level)
+{
+       return logging_level >= level;
+}
+
+#define storvsc_log(dev, level, fmt, ...)                      \
+do {                                                           \
+       if (do_logging(level))                                  \
+               dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
+} while (0)
+
 struct vmscsi_win8_extension {
        /*
         * The following were added in Windows 8
@@ -941,7 +961,8 @@ static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
 
        if (scmnd->result) {
                if (scsi_normalize_sense(scmnd->sense_buffer,
-                               SCSI_SENSE_BUFFERSIZE, &sense_hdr))
+                               SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
+                   do_logging(STORVSC_LOGGING_ERROR))
                        scsi_print_sense_hdr(scmnd->device, "storvsc",
                                             &sense_hdr);
        }
@@ -995,6 +1016,13 @@ 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)
+               storvsc_log(device, STORVSC_LOGGING_WARN,
+                       "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);
 
        if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
                /* CHECK_CONDITION */
@@ -1002,6 +1030,10 @@ static void storvsc_on_io_completion(struct hv_device *device,
                        SRB_STATUS_AUTOSENSE_VALID) {
                        /* autosense data available */
 
+                       storvsc_log(device, STORVSC_LOGGING_WARN,
+                               "stor pkt %p autosense data valid - len %d\n",
+                               request, vstor_packet->vm_srb.sense_info_length);
+
                        memcpy(request->cmd->sense_buffer,
                               vstor_packet->vm_srb.sense_data,
                               vstor_packet->vm_srb.sense_info_length);