zinject: make iotype extendable

I'm about to add a new "type", and I need somewhere to put it!

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #16947

cmd/zinject/zinject.c

@@ -242,6 +242,35 @@ err_to_str(int err)
 	return ("[unknown]");
 }
 
+static const char *const iotypestrtable[ZINJECT_IOTYPES] = {
+	[ZINJECT_IOTYPE_NULL]	= "null",
+	[ZINJECT_IOTYPE_READ]	= "read",
+	[ZINJECT_IOTYPE_WRITE]	= "write",
+	[ZINJECT_IOTYPE_FREE]	= "free",
+	[ZINJECT_IOTYPE_CLAIM]	= "claim",
+	[ZINJECT_IOTYPE_FLUSH]	= "flush",
+	[ZINJECT_IOTYPE_TRIM]	= "trim",
+	[ZINJECT_IOTYPE_ALL]	= "all",
+};
+
+static zinject_iotype_t
+str_to_iotype(const char *arg)
+{
+	for (uint_t iotype = 0; iotype < ZINJECT_IOTYPES; iotype++)
+		if (iotypestrtable[iotype] != NULL &&
+		    strcasecmp(iotypestrtable[iotype], arg) == 0)
+			return (iotype);
+	return (ZINJECT_IOTYPES);
+}
+
+static const char *
+iotype_to_str(zinject_iotype_t iotype)
+{
+	if (iotype >= ZINJECT_IOTYPES || iotypestrtable[iotype] == NULL)
+		return ("[unknown]");
+	return (iotypestrtable[iotype]);
+}
+
 /*
  * Print usage message.
  */
@@ -435,10 +464,6 @@ static int
 print_device_handler(int id, const char *pool, zinject_record_t *record,
     void *data)
 {
-	static const char *iotypestr[] = {
-	    "null", "read", "write", "free", "claim", "flush", "trim", "all",
-	};
-
 	int *count = data;
 
 	if (record->zi_guid == 0 || record->zi_func[0] != '\0')
@@ -465,7 +490,7 @@ print_device_handler(int id, const char *pool, zinject_record_t *record,
 
 	(void) printf("%3d  %-15s  %llx  %-5s  %-10s  %8.4f%%  "
 	    "%6lu  %6lu\n", id, pool, (u_longlong_t)record->zi_guid,
-	    iotypestr[record->zi_iotype], err_to_str(record->zi_error),
+	    iotype_to_str(record->zi_iotype), err_to_str(record->zi_error),
 	    freq, record->zi_match_count, record->zi_inject_count);
 
 	return (0);
@@ -866,7 +891,7 @@ main(int argc, char **argv)
 	int quiet = 0;
 	int error = 0;
 	int domount = 0;
-	int io_type = ZIO_TYPES;
+	int io_type = ZINJECT_IOTYPE_ALL;
 	int action = VDEV_STATE_UNKNOWN;
 	err_type_t type = TYPE_INVAL;
 	err_type_t label = TYPE_INVAL;
@@ -1060,19 +1085,8 @@ main(int argc, char **argv)
 			}
 			break;
 		case 'T':
-			if (strcasecmp(optarg, "read") == 0) {
+			io_type = str_to_iotype(optarg);
-				io_type = ZIO_TYPE_READ;
+			if (io_type == ZINJECT_IOTYPES) {
-			} else if (strcasecmp(optarg, "write") == 0) {
-				io_type = ZIO_TYPE_WRITE;
-			} else if (strcasecmp(optarg, "free") == 0) {
-				io_type = ZIO_TYPE_FREE;
-			} else if (strcasecmp(optarg, "claim") == 0) {
-				io_type = ZIO_TYPE_CLAIM;
-			} else if (strcasecmp(optarg, "flush") == 0) {
-				io_type = ZIO_TYPE_FLUSH;
-			} else if (strcasecmp(optarg, "all") == 0) {
-				io_type = ZIO_TYPES;
-			} else {
 				(void) fprintf(stderr, "invalid I/O type "
 				    "'%s': must be 'read', 'write', 'free', "
 				    "'claim', 'flush' or 'all'\n", optarg);
@@ -1194,7 +1208,7 @@ main(int argc, char **argv)
 		}
 
 		if (error == EILSEQ &&
-		    (record.zi_freq == 0 || io_type != ZIO_TYPE_READ)) {
+		    (record.zi_freq == 0 || io_type != ZINJECT_IOTYPE_READ)) {
 			(void) fprintf(stderr, "device corrupt errors require "
 			    "io type read and a frequency value\n");
 			libzfs_fini(g_zfs);
@@ -1209,9 +1223,9 @@ main(int argc, char **argv)
 
 		if (record.zi_nlanes) {
 			switch (io_type) {
-			case ZIO_TYPE_READ:
+			case ZINJECT_IOTYPE_READ:
-			case ZIO_TYPE_WRITE:
+			case ZINJECT_IOTYPE_WRITE:
-			case ZIO_TYPES:
+			case ZINJECT_IOTYPE_ALL:
 				break;
 			default:
 				(void) fprintf(stderr, "I/O type for a delay "

include/sys/zfs_ioctl.h

@@ -456,6 +456,24 @@ typedef enum zinject_type {
 	ZINJECT_DELAY_EXPORT,
 } zinject_type_t;
 
+typedef enum zinject_iotype {
+	/*
+	 * Compatibility: zi_iotype used to be set to ZIO_TYPE_, so make sure
+	 * the corresponding ZINJECT_IOTYPE_ matches. Note that existing here
+	 * does not mean that injections are possible for all these types.
+	 */
+	ZINJECT_IOTYPE_NULL	= ZIO_TYPE_NULL,
+	ZINJECT_IOTYPE_READ	= ZIO_TYPE_READ,
+	ZINJECT_IOTYPE_WRITE	= ZIO_TYPE_WRITE,
+	ZINJECT_IOTYPE_FREE	= ZIO_TYPE_FREE,
+	ZINJECT_IOTYPE_CLAIM	= ZIO_TYPE_CLAIM,
+	ZINJECT_IOTYPE_FLUSH	= ZIO_TYPE_FLUSH,
+	ZINJECT_IOTYPE_TRIM	= ZIO_TYPE_TRIM,
+	ZINJECT_IOTYPE_ALL	= ZIO_TYPES,
+	/* Room for future expansion for ZIO_TYPE_* */
+	ZINJECT_IOTYPES		= 16,
+} zinject_iotype_t;
+
 typedef struct zfs_share {
 	uint64_t	z_exportdata;
 	uint64_t	z_sharedata;

module/zfs/zio_inject.c

@@ -376,6 +376,27 @@ zio_inject_bitflip_cb(void *data, size_t len, void *private)
 	return (1);	/* stop after first flip */
 }
 
+/* Test if this zio matches the iotype from the injection record. */
+static boolean_t
+zio_match_iotype(zio_t *zio, uint32_t iotype)
+{
+	ASSERT3P(zio, !=, NULL);
+
+	/* Unknown iotype, maybe from a newer version of zinject. Reject it. */
+	if (iotype >= ZINJECT_IOTYPES)
+		return (B_FALSE);
+
+	/* Standard IO types, match against ZIO type. */
+	if (iotype < ZINJECT_IOTYPE_ALL)
+		return (iotype == zio->io_type);
+
+	/* Match any standard IO type. */
+	if (iotype == ZINJECT_IOTYPE_ALL)
+		return (B_TRUE);
+
+	return (B_FALSE);
+}
+
 static int
 zio_handle_device_injection_impl(vdev_t *vd, zio_t *zio, int err1, int err2)
 {
@@ -410,9 +431,8 @@ zio_handle_device_injection_impl(vdev_t *vd, zio_t *zio, int err1, int err2)
 			}
 
 			/* Handle type specific I/O failures */
-			if (zio != NULL &&
+			if (zio != NULL && !zio_match_iotype(zio,
-			    handler->zi_record.zi_iotype != ZIO_TYPES &&
+			    handler->zi_record.zi_iotype))
-			    handler->zi_record.zi_iotype != zio->io_type)
 				continue;
 
 			if (handler->zi_record.zi_error == err1 ||
@@ -635,10 +655,8 @@ zio_handle_io_delay(zio_t *zio)
 			continue;
 
 		/* also match on I/O type (e.g., -T read) */
-		if (handler->zi_record.zi_iotype != ZIO_TYPES &&
+		if (!zio_match_iotype(zio, handler->zi_record.zi_iotype))
-		    handler->zi_record.zi_iotype != zio->io_type) {
 			continue;
-		}
 
 		/*
 		 * Defensive; should never happen as the array allocation