Correct compilation errors reported by GCC 10/11

cmd/zfs/zfs_iter.c

@@ -453,23 +453,21 @@ zfs_for_each(int argc, char **argv, int flags, zfs_type_t types,
 		cb.cb_flags |= ZFS_ITER_RECURSE;
 		ret = zfs_iter_root(g_zfs, zfs_callback, &cb);
 	} else {
-		int i;
-		zfs_handle_t *zhp;
-		zfs_type_t argtype;
+		zfs_handle_t *zhp = NULL;
+		zfs_type_t argtype = types;
 
 		/*
 		 * If we're recursive, then we always allow filesystems as
 		 * arguments.  If we also are interested in snapshots or
 		 * bookmarks, then we can take volumes as well.
 		 */
-		argtype = types;
 		if (flags & ZFS_ITER_RECURSE) {
 			argtype |= ZFS_TYPE_FILESYSTEM;
 			if (types & (ZFS_TYPE_SNAPSHOT | ZFS_TYPE_BOOKMARK))
 				argtype |= ZFS_TYPE_VOLUME;
 		}
 
-		for (i = 0; i < argc; i++) {
+		for (int i = 0; i < argc; i++) {
 			if (flags & ZFS_ITER_ARGS_CAN_BE_PATHS) {
 				zhp = zfs_path_to_zhandle(g_zfs, argv[i],
 				    argtype);

cmd/zpool_influxdb/zpool_influxdb.c

@@ -278,7 +278,7 @@ get_vdev_name(nvlist_t *nvroot, const char *parent_name)
 		    vdev_type);
 	} else {
 		(void) snprintf(vdev_name, sizeof (vdev_name),
-		    "%s/%s-%llu",
+		    "%.220s/%s-%llu",
 		    parent_name, vdev_type, (u_longlong_t)vdev_id);
 	}
 	return (vdev_name);

include/sys/fs/zfs.h

@@ -50,6 +50,7 @@ extern "C" {
  * combined into masks that can be passed to various functions.
  */
 typedef enum {
+	ZFS_TYPE_INVALID	= 0,
 	ZFS_TYPE_FILESYSTEM	= (1 << 0),
 	ZFS_TYPE_SNAPSHOT	= (1 << 1),
 	ZFS_TYPE_VOLUME		= (1 << 2),

lib/libzfs/libzfs_dataset.c

@@ -3972,13 +3972,10 @@ zfs_clone(zfs_handle_t *zhp, const char *target, nvlist_t *props)
 	/* do the clone */
 
 	if (props) {
-		zfs_type_t type;
+		zfs_type_t type = ZFS_TYPE_FILESYSTEM;
 
-		if (ZFS_IS_VOLUME(zhp)) {
+		if (ZFS_IS_VOLUME(zhp))
 			type = ZFS_TYPE_VOLUME;
-		} else {
-			type = ZFS_TYPE_FILESYSTEM;
-		}
 		if ((props = zfs_valid_proplist(hdl, type, props, zoned,
 		    zhp, zhp->zpool_hdl, B_TRUE, errbuf)) == NULL)
 			return (-1);

lib/libzfs/libzfs_sendrecv.c

@@ -807,8 +807,9 @@ dump_ioctl(zfs_handle_t *zhp, const char *fromsnap, uint64_t fromsnap_obj,
 		char errbuf[1024];
 		int error = errno;
 
-		(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
-		    "warning: cannot send '%s'"), zhp->zfs_name);
+		(void) snprintf(errbuf, sizeof (errbuf), "%s '%s'",
+		    dgettext(TEXT_DOMAIN, "warning: cannot send"),
+		    zhp->zfs_name);
 
 		if (debugnv != NULL) {
 			fnvlist_add_uint64(thisdbg, "error", error);
@@ -4196,7 +4197,7 @@ zfs_receive_one(libzfs_handle_t *hdl, int infd, const char *tosnap,
 	nvlist_t *rcvprops = NULL; /* props received from the send stream */
 	nvlist_t *oxprops = NULL; /* override (-o) and exclude (-x) props */
 	nvlist_t *origprops = NULL; /* original props (if destination exists) */
-	zfs_type_t type;
+	zfs_type_t type = ZFS_TYPE_INVALID;
 	boolean_t toplevel = B_FALSE;
 	boolean_t zoned = B_FALSE;
 	boolean_t hastoken = B_FALSE;

lib/libzfs/os/freebsd/libzfs_compat.c

@@ -199,18 +199,18 @@ execvpe(const char *name, char * const argv[], char * const envp[])
 	return (execvPe(name, path, argv, envp));
 }
 
-#define	ERRBUFLEN 256
+#define	ERRBUFLEN 1024
 
 static __thread char errbuf[ERRBUFLEN];
 
 const char *
 libzfs_error_init(int error)
 {
 	char *msg = errbuf;
-	size_t len, msglen = ERRBUFLEN;
+	size_t msglen = sizeof (errbuf);
 
 	if (modfind("zfs") < 0) {
-		len = snprintf(msg, msglen, dgettext(TEXT_DOMAIN,
+		size_t len = snprintf(msg, msglen, dgettext(TEXT_DOMAIN,
 		    "Failed to load %s module: "), ZFS_KMOD);
 		msg += len;
 		msglen -= len;
@@ -285,7 +285,6 @@ zfs_jail(zfs_handle_t *zhp, int jailid, int attach)
 {
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	zfs_cmd_t zc = {"\0"};
-	char errbuf[1024];
 	unsigned long cmd;
 	int ret;
 
@@ -314,6 +313,10 @@ zfs_jail(zfs_handle_t *zhp, int jailid, int attach)
 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
 		    "vdevs can not be jailed"));
 		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
+	case ZFS_TYPE_INVALID:
+		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+		    "invalid zfs_type_t: ZFS_TYPE_INVALID"));
+		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
 	case ZFS_TYPE_POOL:
 	case ZFS_TYPE_FILESYSTEM:
 		/* OK */

lib/libzutil/os/linux/zutil_import_os.c

@@ -754,6 +754,9 @@ encode_device_strings(const char *path, vdev_dev_strs_t *ds,
 
 	return (ret);
 #else
+	(void) path;
+	(void) ds;
+	(void) wholedisk;
 	return (ENOENT);
 #endif
 }

module/zfs/zcp_get.c

@@ -76,9 +76,8 @@ get_objset_type(dsl_dataset_t *ds, zfs_type_t *type)
 static int
 get_objset_type_name(dsl_dataset_t *ds, char *str)
 {
-	int error;
-	zfs_type_t type;
-	error = get_objset_type(ds, &type);
+	zfs_type_t type = ZFS_TYPE_INVALID;
+	int error = get_objset_type(ds, &type);
 	if (error != 0)
 		return (error);
 	switch (type) {
@@ -230,7 +229,7 @@ get_special_prop(lua_State *state, dsl_dataset_t *ds, const char *dsname,
 	char *strval = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
 	char setpoint[ZFS_MAX_DATASET_NAME_LEN] =
 	    "Internal error - setpoint not determined";
-	zfs_type_t ds_type = -1;
+	zfs_type_t ds_type = ZFS_TYPE_INVALID;
 	zprop_type_t prop_type = zfs_prop_get_type(zfs_prop);
 	(void) get_objset_type(ds, &ds_type);
 
@@ -497,8 +496,7 @@ get_zap_prop(lua_State *state, dsl_dataset_t *ds, zfs_prop_t zfs_prop)
 boolean_t
 prop_valid_for_ds(dsl_dataset_t *ds, zfs_prop_t zfs_prop)
 {
-	int error;
-	zfs_type_t zfs_type;
+	zfs_type_t zfs_type = ZFS_TYPE_INVALID;
 
 	/* properties not supported */
 	if ((zfs_prop == ZFS_PROP_ISCSIOPTIONS) ||
@@ -509,7 +507,7 @@ prop_valid_for_ds(dsl_dataset_t *ds, zfs_prop_t zfs_prop)
 	if ((zfs_prop == ZFS_PROP_ORIGIN) && (!dsl_dir_is_clone(ds->ds_dir)))
 		return (B_FALSE);
 
-	error = get_objset_type(ds, &zfs_type);
+	int error = get_objset_type(ds, &zfs_type);
 	if (error != 0)
 		return (B_FALSE);
 	return (zfs_prop_valid_for_type(zfs_prop, zfs_type, B_FALSE));