[SCSI] libosd: SCSI/OSD Sense decoding support

Implementation of the osd_req_decode_sense() API. Can be called by
library users to decode what failed in command executions.

Add SCSI_OSD_DPRINT_SENSE Kconfig variable. Possible values are:
0 - Do not print any errors to messages file <KERN_ERR>
1 - (Default) Print only decoded errors that are not recoverable.
    Recoverable errors are those that the target has complied with
    the request but with a warning. For example read passed end of
    object will return zeros after the last valid byte.
2- Print all errors.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/osd/Kbuild

@@ -20,6 +20,12 @@ ccflags-y += -DCONFIG_SCSI_OSD_INITIATOR -DCONFIG_SCSI_OSD_INITIATOR_MODULE
 CONFIG_SCSI_OSD_ULD=m
 ccflags-y += -DCONFIG_SCSI_OSD_ULD -DCONFIG_SCSI_OSD_ULD_MODULE
 
+# CONFIG_SCSI_OSD_DPRINT_SENSE =
+#	0 - no print of errors
+#	1 - print errors
+#	2 - errors + warrnings
+ccflags-y += -DCONFIG_SCSI_OSD_DPRINT_SENSE=1
+
 # Uncomment to turn debug on
 # ccflags-y += -DCONFIG_SCSI_OSD_DEBUG
 

drivers/scsi/osd/osd_initiator.c

@@ -42,6 +42,8 @@
 #include <scsi/osd_initiator.h>
 #include <scsi/osd_sec.h>
 #include <scsi/osd_attributes.h>
+#include <scsi/osd_sense.h>
+
 #include <scsi/scsi_device.h>
 
 #include "osd_debug.h"
@@ -1339,6 +1341,195 @@ int osd_finalize_request(struct osd_request *or,
 }
 EXPORT_SYMBOL(osd_finalize_request);
 
+#define OSD_SENSE_PRINT1(fmt, a...) \
+	do { \
+		if (__cur_sense_need_output) \
+			OSD_ERR(fmt, ##a); \
+	} while (0)
+
+#define OSD_SENSE_PRINT2(fmt, a...) OSD_SENSE_PRINT1("    " fmt, ##a)
+
+int osd_req_decode_sense_full(struct osd_request *or,
+	struct osd_sense_info *osi, bool silent,
+	struct osd_obj_id *bad_obj_list __unused, int max_obj __unused,
+	struct osd_attr *bad_attr_list, int max_attr)
+{
+	int sense_len, original_sense_len;
+	struct osd_sense_info local_osi;
+	struct scsi_sense_descriptor_based *ssdb;
+	void *cur_descriptor;
+#if (CONFIG_SCSI_OSD_DPRINT_SENSE == 0)
+	const bool __cur_sense_need_output = false;
+#else
+	bool __cur_sense_need_output = !silent;
+#endif
+
+	if (!or->request->errors)
+		return 0;
+
+	ssdb = or->request->sense;
+	sense_len = or->request->sense_len;
+	if ((sense_len < (int)sizeof(*ssdb) || !ssdb->sense_key)) {
+		OSD_ERR("Block-layer returned error(0x%x) but "
+			"sense_len(%u) || key(%d) is empty\n",
+			or->request->errors, sense_len, ssdb->sense_key);
+		return -EIO;
+	}
+
+	if ((ssdb->response_code != 0x72) && (ssdb->response_code != 0x73)) {
+		OSD_ERR("Unrecognized scsi sense: rcode=%x length=%d\n",
+			ssdb->response_code, sense_len);
+		return -EIO;
+	}
+
+	osi = osi ? : &local_osi;
+	memset(osi, 0, sizeof(*osi));
+	osi->key = ssdb->sense_key;
+	osi->additional_code = be16_to_cpu(ssdb->additional_sense_code);
+	original_sense_len = ssdb->additional_sense_length + 8;
+
+#if (CONFIG_SCSI_OSD_DPRINT_SENSE == 1)
+	if (__cur_sense_need_output)
+		__cur_sense_need_output = (osi->key > scsi_sk_recovered_error);
+#endif
+	OSD_SENSE_PRINT1("Main Sense information key=0x%x length(%d, %d) "
+			"additional_code=0x%x\n",
+			osi->key, original_sense_len, sense_len,
+			osi->additional_code);
+
+	if (original_sense_len < sense_len)
+		sense_len = original_sense_len;
+
+	cur_descriptor = ssdb->ssd;
+	sense_len -= sizeof(*ssdb);
+	while (sense_len > 0) {
+		struct scsi_sense_descriptor *ssd = cur_descriptor;
+		int cur_len = ssd->additional_length + 2;
+
+		sense_len -= cur_len;
+
+		if (sense_len < 0)
+			break; /* sense was truncated */
+
+		switch (ssd->descriptor_type) {
+		case scsi_sense_information:
+		case scsi_sense_command_specific_information:
+		{
+			struct scsi_sense_command_specific_data_descriptor
+				*sscd = cur_descriptor;
+
+			osi->command_info =
+				get_unaligned_be64(&sscd->information) ;
+			OSD_SENSE_PRINT2(
+				"command_specific_information 0x%llx \n",
+				_LLU(osi->command_info));
+			break;
+		}
+		case scsi_sense_key_specific:
+		{
+			struct scsi_sense_key_specific_data_descriptor
+				*ssks = cur_descriptor;
+
+			osi->sense_info = get_unaligned_be16(&ssks->value);
+			OSD_SENSE_PRINT2(
+				"sense_key_specific_information %u"
+				"sksv_cd_bpv_bp (0x%x)\n",
+				osi->sense_info, ssks->sksv_cd_bpv_bp);
+			break;
+		}
+		case osd_sense_object_identification:
+		{ /*FIXME: Keep first not last, Store in array*/
+			struct osd_sense_identification_data_descriptor
+				*osidd = cur_descriptor;
+
+			osi->not_initiated_command_functions =
+				le32_to_cpu(osidd->not_initiated_functions);
+			osi->completed_command_functions =
+				le32_to_cpu(osidd->completed_functions);
+			osi->obj.partition = be64_to_cpu(osidd->partition_id);
+			osi->obj.id = be64_to_cpu(osidd->object_id);
+			OSD_SENSE_PRINT2(
+				"object_identification pid=0x%llx oid=0x%llx\n",
+				_LLU(osi->obj.partition), _LLU(osi->obj.id));
+			OSD_SENSE_PRINT2(
+				"not_initiated_bits(%x) "
+				"completed_command_bits(%x)\n",
+				osi->not_initiated_command_functions,
+				osi->completed_command_functions);
+			break;
+		}
+		case osd_sense_response_integrity_check:
+		{
+			struct osd_sense_response_integrity_check_descriptor
+				*osricd = cur_descriptor;
+			const unsigned len =
+					  sizeof(osricd->integrity_check_value);
+			char key_dump[len*4 + 2]; /* 2nibbles+space+ASCII */
+
+			hex_dump_to_buffer(osricd->integrity_check_value, len,
+				       32, 1, key_dump, sizeof(key_dump), true);
+			OSD_SENSE_PRINT2("response_integrity [%s]\n", key_dump);
+		}
+		case osd_sense_attribute_identification:
+		{
+			struct osd_sense_attributes_data_descriptor
+				*osadd = cur_descriptor;
+			int len = min(cur_len, sense_len);
+			int i = 0;
+			struct osd_sense_attr *pattr = osadd->sense_attrs;
+
+			while (len < 0) {
+				u32 attr_page = be32_to_cpu(pattr->attr_page);
+				u32 attr_id = be32_to_cpu(pattr->attr_id);
+
+				if (i++ == 0) {
+					osi->attr.attr_page = attr_page;
+					osi->attr.attr_id = attr_id;
+				}
+
+				if (bad_attr_list && max_attr) {
+					bad_attr_list->attr_page = attr_page;
+					bad_attr_list->attr_id = attr_id;
+					bad_attr_list++;
+					max_attr--;
+				}
+				OSD_SENSE_PRINT2(
+					"osd_sense_attribute_identification"
+					"attr_page=0x%x attr_id=0x%x\n",
+					attr_page, attr_id);
+			}
+		}
+		/*These are not legal for OSD*/
+		case scsi_sense_field_replaceable_unit:
+			OSD_SENSE_PRINT2("scsi_sense_field_replaceable_unit\n");
+			break;
+		case scsi_sense_stream_commands:
+			OSD_SENSE_PRINT2("scsi_sense_stream_commands\n");
+			break;
+		case scsi_sense_block_commands:
+			OSD_SENSE_PRINT2("scsi_sense_block_commands\n");
+			break;
+		case scsi_sense_ata_return:
+			OSD_SENSE_PRINT2("scsi_sense_ata_return\n");
+			break;
+		default:
+			if (ssd->descriptor_type <= scsi_sense_Reserved_last)
+				OSD_SENSE_PRINT2(
+					"scsi_sense Reserved descriptor (0x%x)",
+					ssd->descriptor_type);
+			else
+				OSD_SENSE_PRINT2(
+					"scsi_sense Vendor descriptor (0x%x)",
+					ssd->descriptor_type);
+		}
+
+		cur_descriptor += cur_len;
+	}
+
+	return (osi->key > scsi_sk_recovered_error) ? -EIO : 0;
+}
+EXPORT_SYMBOL(osd_req_decode_sense_full);
+
 /*
  * Implementation of osd_sec.h API
  * TODO: Move to a separate osd_sec.c file at a later stage.

include/scsi/osd_initiator.h

@@ -216,6 +216,55 @@ int osd_execute_request(struct osd_request *or);
 int osd_execute_request_async(struct osd_request *or,
 	osd_req_done_fn *done, void *private);
 
+/**
+ * osd_req_decode_sense_full - Decode sense information after execution.
+ *
+ * @or:           - osd_request to examine
+ * @osi           - Recievs a more detailed error report information (optional).
+ * @silent        - Do not print to dmsg (Even if enabled)
+ * @bad_obj_list  - Some commands act on multiple objects. Failed objects will
+ *                  be recieved here (optional)
+ * @max_obj       - Size of @bad_obj_list.
+ * @bad_attr_list - List of failing attributes (optional)
+ * @max_attr      - Size of @bad_attr_list.
+ *
+ * After execution, sense + return code can be analyzed using this function. The
+ * return code is the final disposition on the error. So it is possible that a
+ * CHECK_CONDITION was returned from target but this will return NO_ERROR, for
+ * example on recovered errors. All parameters are optional if caller does
+ * not need any returned information.
+ * Note: This function will also dump the error to dmsg according to settings
+ * of the SCSI_OSD_DPRINT_SENSE Kconfig value. Set @silent if you know the
+ * command would routinely fail, to not spam the dmsg file.
+ */
+struct osd_sense_info {
+	int key;		/* one of enum scsi_sense_keys */
+	int additional_code ;	/* enum osd_additional_sense_codes */
+	union { /* Sense specific information */
+		u16 sense_info;
+		u16 cdb_field_offset; 	/* scsi_invalid_field_in_cdb */
+	};
+	union { /* Command specific information */
+		u64 command_info;
+	};
+
+	u32 not_initiated_command_functions; /* osd_command_functions_bits */
+	u32 completed_command_functions; /* osd_command_functions_bits */
+	struct osd_obj_id obj;
+	struct osd_attr attr;
+};
+
+int osd_req_decode_sense_full(struct osd_request *or,
+	struct osd_sense_info *osi, bool silent,
+	struct osd_obj_id *bad_obj_list, int max_obj,
+	struct osd_attr *bad_attr_list, int max_attr);
+
+static inline int osd_req_decode_sense(struct osd_request *or,
+	struct osd_sense_info *osi)
+{
+	return osd_req_decode_sense_full(or, osi, false, NULL, 0, NULL, 0);
+}
+
 /**
  * osd_end_request - return osd_request to free store
  *