Re: T10-PI: Getting failed tag info

Martin K. Petersen
2014-12-12T03:12:17Z

>>>>> "Vlad" == Vladislav Bolkhovitin <vst@vlnb.net> writes:

Vlad,

Vlad> We are currently developing a SCSI target system with T10-PI. We
Vlad> are using block integrity interface and found a problem that this
Vlad> interface fundamentally can not pass Oracle T10-PI certification
Vlad> tests. Those tests require to receive on the initiator side
Vlad> information about which particular tag failed the target checks,
Vlad> but the block integrity interface does not preserve this
Vlad> information, hence the target can not deliver it to the initiator
Vlad> => certification failure. The storage provides the right sense,
Vlad> but then in scsi_io_completion() it is dropped and replaced by a
Vlad> single EILSEQ.

Vlad> What would be the best way to fix that? By making a patch
Vlad> introducing new -EXXXXXX error codes for the PI errors?

I posted such a patch a while back. We use that in our qualification
tooling to ensure that the right things are reported when a PI error is
injected at various places in the stack.

One thing that needs to be done is to make returning these new errors to
userland conditional on !BIP_BLOCK_INTEGRITY. I'll put that on my list.

--
Martin K. Petersen Oracle Linux Engineering

block: Add specific data integrity errors

Introduce a set of error codes that can be used by the block integrity
subsystem to signal which class of error was encountered by either the
I/O controller or the storage device.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/block/blk-core.c b/block/blk-core.c
index 6f8dba161bfe..bde1de440b03 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2442,6 +2442,18 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
case -ENODATA:
error_type = "critical medium";
break;
+ case -ECTRLGRD:
+ case -ECTRLAPP:
+ case -ECTRLREF:
+ case -EDISKGRD:
+ case -EDISKAPP:
+ case -EDISKREF:
+ case -EKERNGRD:
+ case -EKERNAPP:
+ case -EKERNREF:
+ case -EILSEQ:
+ error_type = "data integrity";
+ break;
case -EIO:
default:
error_type = "I/O";
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index f4167b013d99..c05e86f4dded 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1210,6 +1210,15 @@ static int noretry_error(int error)
case -EOPNOTSUPP:
case -EREMOTEIO:
case -EILSEQ:
+ case -ECTRLGRD:
+ case -ECTRLAPP:
+ case -ECTRLREF:
+ case -EDISKGRD:
+ case -EDISKAPP:
+ case -EDISKREF:
+ case -EKERNGRD:
+ case -EKERNAPP:
+ case -EKERNREF:
case -ENODATA:
case -ENOSPC:
return 1;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 85cf0ef843f6..9f9e5770606b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -837,7 +837,20 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
action = ACTION_REPREP;
} else if (sshdr.asc == 0x10) /* DIX */ {
action = ACTION_FAIL;
- error = -EILSEQ;
+ switch (sshdr.ascq) {
+ case 0x1:
+ error = -ECTRLGRD;
+ break;
+ case 0x2:
+ error = -ECTRLAPP;
+ break;
+ case 0x3:
+ error = -ECTRLREF;
+ break;
+ default:
+ error = -EILSEQ;
+ break;
+ }
/* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
} else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
action = ACTION_FAIL;
@@ -847,8 +860,22 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
break;
case ABORTED_COMMAND:
action = ACTION_FAIL;
- if (sshdr.asc == 0x10) /* DIF */
- error = -EILSEQ;
+ if (sshdr.asc == 0x10) { /* DIF */
+ switch (sshdr.ascq) {
+ case 0x1:
+ error = -EDISKGRD;
+ break;
+ case 0x2:
+ error = -EDISKAPP;
+ break;
+ case 0x3:
+ error = -EDISKREF;
+ break;
+ default:
+ error = -EILSEQ;
+ break;
+ }
+ }
break;
case NOT_READY:
/* If the device is in the process of becoming
diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-generic/errno.h
index 1e1ea6e6e7a5..d89af4ba1e04 100644
--- a/include/uapi/asm-generic/errno.h
+++ b/include/uapi/asm-generic/errno.h
@@ -110,4 +110,15 @@

#define EHWPOISON 133 /* Memory page has hardware error */

+/* data integrity errors */
+#define ECTRLGRD 134 /* I/O controller detected guard tag error */
+#define ECTRLAPP 135 /* I/O controller detected app tag error */
+#define ECTRLREF 136 /* I/O controller detected ref tag error */
+#define EDISKGRD 137 /* Storage device detected guard tag error */
+#define EDISKAPP 138 /* Storage device detected app tag error */
+#define EDISKREF 139 /* Storage device detected ref tag error */
+#define EKERNGRD 140 /* Kernel detected guard tag error */
+#define EKERNAPP 141 /* Kernel detected app tag error */
+#define EKERNREF 142 /* Kernel detected ref tag error */
+
#endif